! Fanta

! Anna

! Kirki

! Anastasiya

! Douglas

! Anish

! Nirakar

! Joy

Hugo

Remediation! of! soil! contaminated! by! polycyclic! aromatic! hydrocarbons! (PAHs)! is! an! important! societal,! environmental,! economical! and! technological! challenge,! due! to! the! high! number! of! sites! contaminated! by! these! persistent! and! toxic! compounds.! Environmental! engineering! companies! using! conventional! bioremediation! processes! often! fails! to! reach! sufficient! PAH! removal! rates! from! historically! contaminated! soils.! Therefore,!there!is!a!real!need!for!the!development!of!innovative!solutions.! In! the! present! work,! the! characterization! of! 6! historically! tar! oilFcontaminated! soils! showed! that! 42! to! 86%! of! PAH! are! located! in! the! sand! fraction,! either! adsorbed! on! various! coal/coke/wood! particles! or! integrated! in! resinified! and! weathered! tar! oil! particles.! Thus,! either! selective! separation! of! the! most! contaminated! fraction! or! surfactantFenhanced! soil! washing! (SW)! appears! to! be! promising! alternatives! to! bioremediation,!according!to!the!level!of!sequestration!of!PAHs.!Further!investigations! were!performed!on!the!surfactantFenhanced!SW!process,!which!is!based!on!the!transfer! of! PAHs! from! the! soilFsorbed! fraction! to! the! washing! solution.! This! process! generates! SW! solutions! containing! a! large! amount! of! surfactant! and! pollutant.! They! have! to! be! treated! in! order! to! avoid! environmental! contamination! and! ensure! the! costF effectiveness!of!the!whole!process.! Anodic! oxidation! (AO)! was! identified! as! a! suitable! and! promising! process! for! the! treatment! of! SW! solutions! containing! PAHs! and! Tween ® ! 80! as! extracting! agent.! The! detailed! understanding! of! mechanisms! involved! in! the! removal! of! organic! compounds! from! SW! solutions! during! AO! allowed! the! implementation! of! two! different! treatment! strategies:! • First,!it!was!emphasized!that!the!use!of!AO!at!low!current!intensity!during!long! treatment! times! (23! h)! allows! the! selective! degradation! of! target! pollutants! (PAHs)!and!the!reuse!of!the!SW!solution!for!additional!SW!steps.!Thus,!the!large! amount! of! Tween ® ! 80! saved! strongly! improves! the! costFeffectiveness! and! ecological!footprint!of!SW!processes,!particularly!when!the!high!sequestration!of! pollutants!requires!several!SW!steps!using!high!surfactant!concentrations.!! ! iv! • In! contrast,! high! removal! rates! of! organic! compounds! and! production! of! more! biodegradable!byFproducts!was!observed!during!short!treatment!times!(3!h)!by! AO! at! high! current! intensity.! Thus,! synergistic! effects! were! obtained! for! the! combination! of! AO! with! a! biological! postFtreatment.! High! removal! rates! with! optimized!operating!costs!can!be!achieved.!Moreover,!AO!can!also!be!used!as!a! postFtreatment! (polishing! step)! for! the! removal! of! hardlyFbiodegradable! compounds.! This! treatment! strategy! aims! at! avoiding! environmental! contamination!by!SW!solutions.! Both! treatment! strategies! have! to! be! considered! for! a! suitable! management! of! SW! solutions.! In! view! of! promising! results! obtained,! scientific! challenges! related! to! the! scaleFup!of!this!process

! xi!

TABLE'OF'CONTENT'

Acknowledgements!!!!! ! ! ! ! ! ! ! !!!!!!!!!! i! Abstract!! !!! !! ! ! ! ! ! ! ! !!!!!!!!!!!!!iii! Résumé!! ! ! ! ! ! ! ! ! ! !!! v! Sintesi!! ! xii!
!! ! ! !!!!!!!! !!!!!!!!!!!!116! 2.3.!Particle!size!separation!! ! ! ! ! ! !!!!!!!!!!!!117! 2.4.!Optical!evalution! ! ! ! ! ! ! ! !!!!!!!!!!!!117! 2.5.!Total!organic!carbon!(TOC)!and!black!carbon!analysis! ! !!!!!!!!!!!!117! 2.6.!PAH!extraction!and!analysis! ! ! ! ! !! !!!!!!!!!!!!117! 2.7.!Enrichment!factor! ! ! ! ! ! ! !!!!!!!!!!!!118! 2.8.!Selective!separation!procedure! ! ! ! ! ! !!!!!!!!!!!!119!
3.'Results'' ' ' ' ' ' ' ' ' ' ''''''''''''120' (ii)" possible" pathways" for" direct" and" indirect" contact" between" pollutants" and" people" (bioavailability)" [4]"and"(iii)"presence"of"people"exposed"to"this"contamination" [5].""

3.1.!Identification!of!black!particles! ! ! ! ! ! !!!!!!!!!!!!120! 3.2.!Role!of!black!particles!in!PAH!distribution!for!aged!tar!oilFcontaminated!! soils! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!124! 3.
! 2.1.!Chemicals! ! ! ! ! ! ! ! !!!!!!!!!!!!147! 2.2.!Preparation!of!solutions!of!humic!acids! ! ! ! !!!!!!!!!!!!147! 2.3.!Electrochemical!treatments! ! ! ! ! ! !!!!!!!!!!!!147! 2.4.!Analytical!procedures! ! ! ! ! ! ! !!!!!!!!!!!!148! 2.5.!Mathematical!modeling!! ! ! ! ! ! !!!!!!!!!!!!149! 3
!!!!!!!!!!!!152! 3.1.1.!Experimental!results!! ! ! ! ! ! !!!!!!!!!!!!152! 3.1.2.!Mathematical!modeling!! ! ! ! ! ! !!!!!!!!!!!!155! 3.2.!Removal!of!humic!acids!during!EFFPt!and!EFFBDD!processes! !!!!!!!!!!!!156! 3.2.1.!Experimental!results!! ! ! ! ! ! !!!!!!!!!!!!156! 3.2.2.!Mathematical!modeling!! ! ! ! ! ! !!!!!!!!!!!!161! 3.3.!Discussion!about!the!model! ! ! ! ! ! !!!!!!!!!!!!
Abstract!! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!176! Graphical!abstract!! ! ! ! ! ! ! ! ! !!!!!!!!!!!!
! ! ! ! ! ! !!!!!!!!!!!!182! 2.2.!Synthetic!and!real!soil!washing!solutions! ! ! ! !!!!!!!!!!!!182! 2.3.!Anodic!oxidation! ! ! ! ! ! ! ! !!!!!!!!!!!!183! 2.4.!Adsorption!experiments! ! ! ! ! ! !!!!!!!!!!!!
References!! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!201! ! !!!!!!!!!!!!215! 2.4.!Analytical!procedures! ! ! ! ! ! ! !!!!!!!!!!!!216! 2.4.1.!Phenanthrene!! ! ! ! ! ! ! !!!!!!!!!!!!216! 2.4.2.!Tween ® !80!! ! ! ! ! ! ! !!!!!!!!!!!!216! 2.4.3.!Chemical!oxygen!demand!! ! ! ! ! !!!!!!!!!!!!217! 2.4.4.!Biodegradability!! ! ! ! ! ! ! !!!!!!!!!!!!217! 2.4.5.!Carboxylic!acids!! ! ! ! ! ! ! !!!!!!!!!!!!217! 2.4.6.!Acute!toxicity!! ! ! ! ! ! ! !!!!!!!!!!!!218!
The" implementation" of" a" common" soil" framework" directive" by" the" EU" is" an" important" political"challenge"for"the"following"years." "

1.2.!A!focus!on!polycyclic!aromatic!hydrocarbon!contaminated!soils!

PAHs" are" chemically" stable" hydrophobic" organic" compounds" made" of" two" or" more" condensed" aromatic" rings." There" are" some" natural" sources" such" as" forest" fires" or" volcanic" eruptions" since" they" are" generated" by" pyrolysis" or" incomplete" combustion" of" organic" compounds" [6,7]." However," their" main" origin" is" anthropogenic;" they" are" common"constituents"of"soot"particles,"coal"tars,"mineral"oils,"etc." [8]."The"development"

of"manufactured"gas"plant"and"the"rise"of"tar"oil"use"during"the"19 th "and"20 th "centuries" strongly"increased"anthropogenic"emissions"and"contaminations"by"PAHs."Due"to"their" toxic," mutagenic" and" carcinogenic" properties" [9,10]," PAHs" are" now" a" critical" environmental"concern."

Here"are"the"main"physicochemical"properties"of"PAHs"that"govern"their"environmental" fate:"

• They" have" a" high" octanol/water" (Kow)" and" organic" carbon" (Koc)" partition" coefficient" as" well" as" a" low" solubility" in" water." Therefore," they" are" persistent" in" the"environment"and"interact"strongly"with"solid"surfaces,"soil"organic"matter"and" non\aqueous"phase"liquid"(NAPL)" [11]."

Introduction 6"
easy"and"relevant"monitoring"of"contaminated"sites"(they"have"been"listed"by"the"United"

States"Environmental"Protection"Agency"(USEPA))" [12]."

There" is" a" strong" heterogeneity" of" regulations" about" PAH\contaminated" soils."

Regulations"depend"on"the"future"use"of"the"soil"and"specific"national"laws."For"example,"

in"France,"a"threshold"of"50"mg"ΣPAH"kg \1 "has"been"defined"for"landfill"disposal"of"inert"

wastes" [13]." In" contrast," Denmark" enforced" a" threshold" value" of" 1.5" mg" ΣPAH" kg \1 " for"

sensitive" land" use." Some" other" countries" also" prefer" to" add" or" to" consider" only" a" threshold"value"for"benzo(a)pyrene,"which"is"one"of"the"most"toxic"PAH" [14]." "

1.3.!Soil!washing!and!other!soil!remediation!processes!

Soil"remediation"is"an"area"of"environmental"engineering"that"did"not"yet"reach"maturity."

Cost\effectiveness" and" robustness" of" most" of" processes" currently" used" have" still" to" be"

further" improved." The" diagnostic" of" a" contaminated" site" is" also" a" critical" step."

Particularly,"the"nature"and"the"location"of"a"contamination"have"to"be"carefully"defined."

Then," there" are" three" main" types" of" treatment," which" have" a" direct" influence" on"

treatment" costs:" inFsitu" (without" excavation)," on\site" (with" excavation," 7" €" t \1 )" and" exF situ" (with" excavation" and" transportation" of" contaminated" soils" to" a" treatment" center," 0.2"€"t \1 "km \1 )" [18]." It" is" also" worth" to" mention" that" soil" remediation" processes" usually" follow"the"following"order"of"effectiveness:"exFsitu">"on\site">"inFsitu."

Several" different" remediation" processes" are" currently" used." However," here" is" a" rapid" overview" of" the" main" drawbacks" of" the" most" widespread" soil" treatment" processes" [19,20]:"

• All" processes" based" on" biodegradation" (natural" attenuation," bioaugmentation," biostimulation," aerobic/anaerobic" biological" treatment," composting," bioslurry)" are" strongly" hindered" by" the" presence" of" highly" sequestrated" and" poorly" bioavailable" pollutants" in" real" historically" polluted" soils." Moreover," in\situ" biodegradation"processes"require"very"long"treatment"times."

Introduction 9"
pollutants"instead"of"total"concentration"in"soils"appears"to"be"a"potential"compromise"

for" the" reduction" of" treatment" costs." But" this" does" not" take" into" account" that" the" currently" non\available" fraction" may" be" then" (partly)" mobilized," either" because" a" new" equilibrium"is"established"after"the"removal"of"the"available"fraction"from"the"aqueous" phase"or"because"environmental"conditions"change"and"the"equilibrium"shifts"towards"a"

higher" solubility" of" pollutants," thus" leading" to" long\term" contaminations." Thus," for" reaching"requirements"based"on"the"total"concentration"of"pollutants"within"reasonable" times" in" case" of" low" (bio)availability" of" pollutants," surfactant\enhanced" SW" might" be" a" more"suitable"process"than"bioremediation" [26]."

" "

Introduction 11"

3.!Objectives!and!thesis!structure!

The"objectives"of"the"treatment"of"SW"solutions"are:"

• to" efficiently" destroy" PAHs" present" in" SW" solutions" and" to" avoid" environmental" contamination"from"discharge"of"SW"solutions;"

• to" reuse" SW" solutions" for" additional" SW" steps" in" order" to" improve" SW" effectiveness,"reduce"surfactant"consumption"and"ensure"the"cost\effectiveness"of" the"whole"process."

This"thesis"is"organized"around"2"main"parts,"as"described"in" Here"is"a"short"description"of"the"6"chapters"following"this"general"introduction:"

• Chapter"1"is"a"literature"review"on"the"treatment"of"SW"solutions."A"large"range"of" processes" are" presented" and" compared" as" regards" to" the" specific" issue" of" SW" solutions."

• Chapter" 2" is" a" study" performed" during" the" mobility" at" the" Helmholtz" Center" for"

Environmental" Research" (Leipzig," Germany)." Characteristics" of" historically" tar" oil\contaminated"soils"are"investigated"and"discussed."A"new"treatment"strategy" is"proposed"and"tested"for"the"most"highly"sequestrated"PAHs."

• Chapter" 3" is" dedicated" to" the" comparison" of" several" different" EAOPs" (AO" and" electro\Fenton,"with"various"electrode"materials)"for"the"removal"of"humic"acids"

(one"of"the"main"component"of"the"soil"organic"matter)."During"electrolysis,"both" sorption"and"oxidation"processes"are"observed,"discussed"and"modeled."

• Chapter" 4" is" a" study" focused" on" the" degradation" mechanisms" of" Tween ® " 80" micelles" and" organic" compounds" entrapped" inside" micelles" during" AO." The" optimal" conditions" for" the" selective" degradation" of" target" pollutants" are" identified." The" reuse" of" a" real" SW" solution" is" tested" on" a" historically" PAH\ contaminated"soil."

Introduction 13"

4.!Novelty!of!the!thesis!!

PAH" contaminated" soils" and" treatment" of" SW" solutions" are" very" challenging" issues" for" environmental"engineering"companies."The"interest"of"the"research"project"carried"out" during" this" thesis" relied" on" the" global" consideration" of" these" issues:" from" the" characterization" of" contaminated" soils" to" the" identification" of" the" most" relevant" treatment"strategies"and"to"the"removal"of"target"pollutants"from"SW"solutions."All"these" aspects"have"to"be"considered"at"the"same"time"in"order"to"provide"suitable"and"relevant" improvements."

The"following"chapters"report"and"discuss"the"new"results"and"scientific"challenges"that" have"been"faced"during"this"thesis."All"the"conferences"attended"and"papers"(published,"

accepted"or"submitted)"related"to"this"thesis"are"listed"in"Appendix"1."

" "

17"

" Chapter 1

24#

widely#reviewed#in#the#literature#either#with#surfactants# [10,11,19,20] The#electrokinetic#surfactant]aided#SF# [24]#can#also#be#used.#In#the#classical#SF#process,# the# driving# force# is# the# pressure# gradient,# while# there# is# a# voltage# gradient# in# the# electrokinetic#surfactant]aided#SF.# The# SF# process# is# appealing# due# to# the# absence# of# a# preliminary# excavation# step,# low# environmental# disruption,# and# reduction# of# worker# exposure# to# hazardous# materials# [25].# However,# this# in:situ# technique# may# lead# to# low# effectiveness# according# to# soil# heterogeneities,# permeability,# porosity# and# type# of# contamination# [23].# Moreover,# displacement#and#extension#of#the#contaminated#zone#is#sometimes#observed#when#the# pumping#system#is#not#well#managed# [23].# #

2.2.(Soil(washing(process(

The# SW# process# is# an# ex' situ# process,# i.e.,# the# soil# has# to# be# excavated# before# the# treatment.# It# is# operated# at# a# certain# solid/liquid# ratio,# in# the# range# 1]100%# [21]# and# most#frequently#between#5#and#40%.#EAs#are#supplied#to#the#system#in#order#to#improve# the# removal# of# contaminants# sorbed# to# the# soil# [26].# The# SW# process# enhances# the# contact# between# EAs# and# soil# pollutants,# thereby# allowing# a# reduction# of# treatment# Chapter 1

27#

times#as#well#as#better#treatment#efficiency#and#treatment#monitoring,#compared#to#the# SF#process# [21].# For# reaching# maximum# removal# rates# and# minimum# costs# related# to# EA# consumption,# the# most# important# parameters# to# consider# are# (i)# the# extraction# capacity# of# the# EA# chosen#(ii)#its#cost#(iii)#its#sorption#to#soil,#which#can#lead#to#important#loss#of#EA#and# adverse# effects# on# the# quality# of# soil# (iv)# the# operating# parameters,# including# concentration# of# EA,# soil/liquid# ratio,# contact# time,# mixing# conditions# and# number# of# successive# washing# steps# [21].# Usually,# preliminary# tests# and# treatability# studies# allow# the#determination#of#the#optimal#parameters#for#the#implementation#of#the#SW#process,# which#depend#mainly#on#the#nature#and#level#of#sequestration#of#pollutants.#Besides,#soil# characteristics# have# also# to# be# considered,# for# example,# high# organic# matter# and# clay# content#could#have#strong#adverse#effects#such#as#competitive#solubilization#of#natural# SOM,#mobilization#of#hardly#settling#particles#and#high#soil#adsorption#of#EAs# [20].#Last# but#not#least,#the#horizontal#and#vertical#location#of#the#contaminated#soil#has#also#to#be# carefully#studied#before#to#excavate#the#soil#fraction#that#will#be#treated.#Excavation#and# treatment#of#non]polluted#soil#strongly#decrease#the#cost]efficiency#of#the#process.# #

2.3.(Extracting(agents((

Extracting#aqueous#solutions#with#or#without#additives#are#employed#to#mobilize#HOCs# from#the#soil#to#the#SW/SF#solution.#Additives#are#used#for#increasing#aqueous#solubility# of#HOCs,#since#it#is#one#of#the#main#controlling#mechanisms#for#SW#efficiency.#These#EAs# reduce#the#time#necessary#to#treat#a#site#compared#to#the#use#of#water#alone.#Aside#from# their#extracting#and#solubilizing# capacities,#they#must#be#of#low#ecotoxicity#for#the#soil# and#biodegradable# [10].#Besides,#they#can#also#lead#to#the#mobilization#of#heavy#metals,# as#it#has#been#recently#reviewed#by #Mao#et#al.#[11].# Chapter 1

29# Among# EAs,# synthetic# surfactants# have# the# best# extraction# effectiveness# [10,27].# However,#some#of#them#are#hardly#biodegradable# [28]#and#affected#by#precipitation#or# sorption# onto# soil,# requiring# larger# amounts# and# possibly# damaging# soils# [19,20] [30]# observed# that# rhamnolipid# (RHA)# and# saponin# (biosurfactants)# exhibited# higher# petroleum#hydrocarbons#removal#efficiency#from#soil#than#TW80#and#TX100#(synthetic# surfactants).# Other# advantages# of# biosurfactants# include# higher# biodegradability,# ecological# safety,# lower# toxicity# and# the# possibility# to# be# produced# in' situ# [29,31].# However,# the# main# issue# that# currently# impairs# their# use# in# SW/SF# processes# is# their# economically#reasonable#production# [29,[START_REF] Khalil | Role" of" Weathered" Coal" Tar" Pitch" in" the" Partitioning" of" Polycyclic" Aromatic" Hydrocarbons" in" Manufactured" Gas" Plant" Site" Sediments[END_REF].## hydrophobic'organic'compounds'(HOCs).'Adapted'from'the'reference' [34].'

There# are# also# many# derivative# β]CDs# such# as# hydroxypropyl]β]CD# (HPCD),# carboxymethyl]β]CD# (CMCD),# methyl]β]CD# (MCD)# or# randomly# methylated]β]CD# (RAMEB).#These#CDs#have#higher#solubility#(in#the#range#100#to#1000#g#L ]1 )#compared#to# the#native#β]CD#(18.5#g#L ]1 #at#25#°C).#
CD]enhanced# SW/SF# processes# have# been# recently# reviewed# [21].# CDs# enhance# water# solubilization#of#many#HOCs# [START_REF] Benhabib | Characteristics"of"a"solid"coal"tar"sampled"from"a" contaminated" soil" and" of" the" organics" transferred" into" water[END_REF].#The#β]CD#is#considered#as#the#most#accessible#and#less# The# • OH# has# the# ability# to# degrade# most# of# organic# and# organo]metallic# pollutants# [47,48]#by#dehydrogenation,#hydroxylation#or#redox#reactions# [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF].#The#degradation#of# organic# compounds# involves# the# formation# of# several# by]products# until# total# mineralization,# i.e.,# conversion# into# carbon# dioxide# (CO2),# water# and# inorganic# ions# [50,51].#This#is#the#reason#why#mineralization#rates#are#much#slower#than#degradation# rates# [50].#Furthermore,#some#by]products#more#toxic#than#the#parent#compound#can#be# formed# [START_REF] Hinds | Aerosol"technology[END_REF].# Therefore,# the# identification# of# these# by]products,# the# understanding# of# degradation#pathways# [START_REF]The$ stock$ solution$ was$ prepared$ L Q1 $of$commercial$HAs$in$milliQQ$water$at$pH$3.$This$solution$was$filtered$ /F$filter$$μm$as$pore$diameter).$Then,$HAs$were$ and$ the$ solution$ was$ centrifuged[END_REF]54]#and#the#evolution#of#the#treated#solution#toxicity#are#also# relevant#parameters#to#study# [55].##

Inclusion$Complex$
The#use#of#ozone,#biological#treatments#and#combined#processes#is#also#discussed#in#this# subsection.#

The# efficiency# of# each# process# for# SW/SF# solutions# treatment# must# be# assessed# as# a# function#of#the#following#specific#objectives# [15,16,56]:## photocatalytic(treatment(of(a(SW/SF(solution.(Adapted(from(the(reference([79].(

The# nature# of# the# surfactant# for# concentrations# much# higher# than# the# CMC# has# an# important# influence# [65].# In# real# SW/SF# solutions# containing###########################
methyl (3,4Tdichlorophenyl) Bandala#et#al.#[109]#reported#the#higher#efficiency#of#the#photoNFenton#process#by#using# SDS# as# EA:# the# degradation# of# 2,4Ndichlorophenoxyacetic# acid# (2,4ND)# after# 50# min# of# treatment# was# <# 5%,# 50%# and# ># 99%# for# UV# irradiation,# Fenton# and# photoNFenton# processes,#respectively.#

#iron#(Fe 2+ ).#Fenton#reaction#is#the#catalytic#decomposition#of#H2O2#by#iron#salts.# It# is# initiated# by# the# formation# of# • OH# in# accordance# with# the# classical# Fenton# reaction# (Eq.#3)#at#acidic#pH#(pH#≈#3)#[47,91]:# Chapter 1 44# !" !! + ! ! ! ! → !" !! + !" ! • + !" ! ##########(k2#=#63#M N1 #s N1 )! (Eq.#3)# Then,#the#process#is#propagated#by#the#catalytic#behavior#of#the#Fe(III)/Fe(II)#couple.#It# can# also# be# coupled# to# catalytic# processes# leading# to# further# ferrous# ions# production.# This# process# presents# some# drawbacks# such# as# the# use# of# high# reagent# concentration,# occurrence#of#parasitic#reactions#consuming# • OH#and#formation#of#process#sludge#under# the# form# of# Fe(OH)3# [90].# One# of# the# wellNknown# way# for# improving# the# efficiency# of# Fenton's# chemistry# is# to# combine# the# classical# Fenton# process# with# UVNA# [92-96]# or# solar#light#[97]#irradiation#(photoNFenton#process).#The#action#of#photons#is#complex#but# mainly#described#by#the#following#reaction#(Eq.#4)#[98].# !"(!") !! + ℎ! → !" !! + !" ! • # (Eq.#4)# Fe(OH) 2+ #is#the#preNeminent#form#of#Fe(III)#in#the#pH#range#2.8#N#3.5#and#UV#light#has#the# ability# to# perform# the# reductive# photolysis# of# Fe(OH) 2+ .# The# benefits# are# twice:# in*situ# generation# of# Fe 2+ # that# catalyzes# the# Fenton# reaction# (Eq.# 3)# and# formation# of# further# • OH.# A# major# drawback# of# the# Fenton# process# is# the# production# of# sludge# from# iron# (III
Results# obtained# by# different# research# groups# are# summarized# in# Table# 1.2.# Fenton# process#has#been#applied#to#different#kinds#of#SW/SF#solutions#with#low#efficiency.#For# Chapter 1 45# example,#it#has#been#reported#46%#removal#of#365#mg#ΣPAHs#L N1 #in#a#solution#containing# 0.1#g#L N1 #of#CAS#(amphoteric#surfactant)#by#using#1.7#mM#of#Fe 2+ #and#17.6#mM#H2O2#at## pH#4#for#the#Fenton#process#[108].#
Similarly#to#adverse#effects#from#SOM,#the#presence#of#high#surfactant#concentration#has# strong#adverse#effects#on#the#efficiency#of#the#Fenton#process#[116].#For#example,#Yang# and# Wang# (2009)# [117]# reported# a# decrease# in# methyl# orange# degradation# rate# with## surfactant#concentration#increasing.#Much#higher#reagent#doses#are#necessary#to#reach# degradation# of# target# pollutants# in# SW/SF# solutions# containing# surfactants# and# SOM# [115].#As# • OH#act#in#a#nonRselective#way,#a#significant#amount#is#wasted#in#the#reactions# with#the#SOM#and#surfactants.#This#is#one#of#the#main#limiting#factor#in#determining#the# economic# feasibility# of# the# process# [116].# Therefore,# it# could# be# concluded# that# the# classical# Fenton# process# is# not# enough# efficient# for# the# treatment# of# SW/SF# solutions# containing# high# surfactant# concentrations.# Besides,# the# use# of# the# photoRFenton# improves#performances#but#also#increases#process#cost.# # ! CDs:+influence+of+nature+and+dose+ A#study#has#compared#the#treatment#of#a#SW#solution#containing#trinitrotoluene#(TNT)# as#target#pollutant#by#the#photoRFenton#process,#with#and#without#the#use#of#CDs#as#EA# [113].#It#has#been#shown#that#the#process#efficiency#is#improved#by#using#MCD.#The#use# of#5#mM#MCD#increased#the#concentration#of#TNT#in#the#SW#solution#by#a#factor#of#2.1;#it# also# improved# the# photoRFenton# oxidation# efficiency.# The# TNT# degradation# rate# was##### 1.3#times#higher#compared#to#the#degradation#in#distilled#water,#despite#the#presence#of# SOM# in# the# real# SF# solution.# In# fact,# MCD# reduced# the# • OH# scavenging# effect# from# nonR target#organic#compounds.#This#has#been#ascribed#to#the#formation#of#a#ternary#complex# (TNTRCDRFe(II))# [113].# The# enhanced# Fenton# degradation# of# PCBs# and# PAHs# by# simultaneous# iron# and# pollutant# complexation# with# CDs# has# also# been# emphasized# by# another# study# [111].# CMCD# is# able# to# remove# HOCs# from# SOM# binding# sites# while# complexing# Fe 2+ # at# the# same# time# [111].# The# formation# of# the# ternary# complex# allows# the#formation#of#radical#species#close#to#the#included#target#molecule#[56].#Interestingly,# it#has#also#been#shown#that#too#low#concentrations#of#iron#could#decrease#the#pollutant# degradation#rate.#This#is#ascribed#to#an#isolation#of#pollutants#away#from# • OH,#because#a# Chapter 1 49# too# small# fraction# of# CMCD# is# bounded# to# iron# [111].# The# formation# of# the# ternary# complex# depends# on# the# functional# group# present# on# the# external# shape.# Iron# is# coordinated# in# different# functional# groups# with# each# CD# [111].# For# example,# metal# binding# is# stronger# with# the# oxygen# in# the# carboxyl# group# of# CMCD# compared# to# the# alcohol#groups#of#native#βRCD.#This#is#the#reason#why#βRCD#and#αRCD#have#lower#ability# to#form#this#ternary#complex#compared#to#CMCD#[111].#Moreover,#Fenton#degradation#of# benzo[a]pyrene#(BAP)#in#the#presence#of#a#radical#scavenger#was#improved#with#HPCD# but# not# in# the# presence# of# RAMEB# [112].# This# confirms# the# importance# of# CD# nature.# Analysis#bringing#evidence#of#the#ternary#complex#formation#include#spectrophotometry# [56],#fluorescence#and#nuclear#magnetic#resonance#spectroscopy#[118,119].# # 3.2.2.2.#Influence#of#operating#conditions# ! Fenton's+reagent+dose+ As# the# oxidizable# organic# matter# in# the# reaction# medium# is# comprised# of# target#
pollutants#as#well#as#EAs#and#SOM,#the#Fenton's#reagent#dose#has#to#be#greatly#increased.# By#using#PCB#as#target#pollutant#(6.4#mg#L R1 )#and#LAS#as#surfactant#(300 [5,46,[137][START_REF] Polcaro | # Oxidation# at# boron# doped# diamond# electrodes:# An# effective# method# to# mineralise# triazines[END_REF][139]

#mg#L R1 ),#3#g#L R1 # of#H2O2#has#been#used#to#reach#more#than#99%#of#PCB#degradation#at#the#end#of#2#h#of# treatment# by# the# photoRFenton# process# [115].# However,# this# high# H2O2# concentration# was#not#sufficient#to#reach#a#sufficient#mineralization#rate,#which#stopped#around#19%.# 30# g# L R1 # of# H2O2# has# been# necessary# to# reach# a# mineralization# rate# of# 96%.# Therefore,# similarly#to#the#classical#Fenton#process,#the#photoRFenton#process#also#requires#the#use# of# large# amounts# of# Fenton's# reagent# during# the# treatment# of# SW/SF# solution# [109].# Another# example,# more# than# 95%# degradation# of# dichlorodiphenyltrichloroethane# (DDT),# dichlorodiphenyldichloroethylene# (DDE),# diesel# and# at# least# 95%# COD# removal# has# been# reported# after# 6# h# of# treatment# by# the# photoRFenton# process# [17].# However,# operating# conditions# included# high# Fenton's# reagent# dose:# FeSO4# at# 12# mM# and# a# sequential# addition# of# 80# mM# of# H2O2# every# 20# min# (i.e.# 1440# mM# of# H2O2# addition# during#the#whole#treatment).# The#use#of#CDs#as#EA#favors#the#removal#of#HOCs#by#Fenton's#reaction#based#processes# [111],#however,#further#comparative#studies#would#be#necessary#in#order#to#determine# Chapter 1 50# how# much# Fenton's# reagent# is# saved# with# the# use# of# CDs,# compared# to# the# use# of# synthetic#surfactants.# It# is# also# well# known# that# the# efficiency# of# the# Fenton# process# depends# on# the# ratio# R#=#[H2O2]/[Fe]# [94,120].# In# most# of# cases,# the# ratio# R# used# for# SW/SF# solutions# treatment#is#chosen#according#to#previous#studies.#For#example,#Tang#and#Huang#[120]# determined# the# optimal# R# as# 11# for# the# degradation# of# 2,4Rdichlorophenol# in# pure# aqueous#solution.# Interestingly,# it# has# been# noticed# that# the# Fenton# process# could# be# performed# without# external#iron#addition,#due#to#the#extraction#of#iron#and#other#transition#metals#from#the# soil#during#the#SW/SF#process#[15].#The#use#of#EAs#with#high#chelating#ability#could#also# be# investigated# in# order# to# improve# this# phenomenon.# However,# it# would# involve# the# investigation#of#other#issues#such#as#cost#and#toxicity#of#the#chelating#agent,#extraction#of# toxic#metals,#etc.#[15].# # ! pH+ It#has#been#reported#that#the#best#pH#to#perform#the#Fenton#process#is#2.8#[98].#However# Fenton# oxidation# of# real# SW/SF# solutions# could# be# successfully# performed# without# pH# adjustment.# This# is# ascribed# to# the# presence# of# substances# able# to# keep# Fe 3+ # in# the# solution#at#near#neutral#pH#(SOM#or#CDs#when#it#is#used#as#EA)#and/or#to#the#formation# of#acidic#degradation#byRproducts#(particularly#carboxylic#acids)#allowing#the#decrease# of#the#pH#around#3#during#the#treatment#[15].# # ! Irradiation+light+(for+the+photo;Fenton+process)+ In# regards# to# the# photoRFenton# process,# the# choice# of# the# irradiation# light# is# an# important# parameter.# Both# UV# lamp# [115]# and# sunlight# [43]# have# been# used# as# irradiation# light# for# the# treatment# of# SW/SF# solutions.# However,# it# is# not# possible# to# clearly#determine#the#influence#of#the#irradiation#light#since#other#operating#conditions# ([H2O2],# [Fe],# R,# pH)# must# be# taken# into# account# for# the# comparison.# A# study# has# investigated#the#effect#of#illumination#source#wavelength#on#the#degradation#of#PCBs#in# Chapter 1 51# SW/SF#solutions#[114].#Iron#(III)#complexes#absorb#more#the#radiation#at#254#nm#than#at# 366#and#440#nm.#This#allows#a#higher#photoreduction#rate#of#iron#(III)#to#iron#(II)#(Eq.#4)# at#254#nm.#Therefore,#higher#effectiveness#was#obtained#by#using#an#illumination#source# centered#at#254.# # 3.3.#Ozone#processes# 3.3.1.#General#considerations# Ozone# (O3)# is# a# strong# oxidant# with# the# fifth# highest# standard# redox# potential# (E°#=#2.07#V/SHE,#at#25#°C)#[45].#Thus,#ozone#processes#have#the#ability#to#oxidize#many# organic# compounds# [123-126].# Ozone# is# produced# by# electrical# discharge# over# site# where# it# will# be# used,# because# of# its# unstable# nature.# Then,# it# is# bubbled# inside# the# effluent#and#transferred#from#the#gas#phase#to#the#liquid#phase.#Ozonation#can#be#limited# by#the#difficulty#to#reach#high#ozone#concentrations#in#water.## The#degradation#of#organic#pollutants#in#water#by#ozone#processes#depends#strongly#on# the#pH#of#the#solution#[126].#If#the#ozonation#is#developed#under#acidic#conditions,#the# main# pathway# for# degradation# of# organics# is# the# direct# oxidation.# Ozone# acts# in# a# selective#way#with#lower#kinetic#rate#constants#(for#example,#in#the#range#1#R#10 3 #M R1 #s R1 # with# chlorophenols)# than# • OH# [57,127].# It# reacts# with# functional# groups# of# organic# pollutants# through# electrophilic,# nucleophilic,# and# dipolar# addition# reactions# [128].# At# higher# pH,# the# decomposition# of# ozone# by# hydroxyl# ions# is# faster# and# the# indirect# process# occurs# following# a# complex# pathway# described# by# PeraRTitus# et# al.# [57].# The# indirect# oxidation# occurs# through# • OH# generation,# which# react# immediately# and# nonR selectively#with#the#organic#matter.#Overall,#at#pH<4#the#direct#oxidation#dominates;#at# 4<pH<9# both# mechanisms# are# present;# at# pH>9# the# indirect# pathway# is# the# main# reaction#[57].# Ozonation#can#also#be#combined#with#homogeneous#promoters#in#presence#or#absence# of# UV# light# (O3/H2O2,# O3/H2O2/UV,# O3/Fe 2+ ,# O3/Fe 2+ /UV)# in# order# to# increase# the# production# of# • OH# [123,124,129].# Moreover,# the# photolysis# of# ozone# leads# to# the# formation#of#H2O2#which#is#further#degraded#into#two# • OH#under#UVRC#irradiation#[125].# Chapter 1 52# 3.3.2.#Removal#efficiency# Ozone# is# often# used# for# in+ situ# chemical# oxidation,# particularly# by# combining# ozone# oxidation# with# a# postRbiological# treatment# of# the# soil# [13].# Some# data# have# also# been# obtained#for#the#treatment#of#SW/SF#solutions#by#ozone#processes.#First,#the#influence#of# pH# and# ozone# dose# on# the# efficiency# of# the# treatment# of# a# SW# solution# containing# 200#mg#L R1 # of# PAHs# has# been# studied# [130].# It# has# not# been# observed# any# significant# effect#from#the#pH#in#the#range#3#R#10.#Only#the#higher#doses#(more#than#500#mg#O3#L R1 )# decreased#the#amount#of#PAHs#(45R65%#removal)#in#the#solution.#Similar#efficiency#has# been# obtained# for# the# treatment# of# SW/SF# solutions# containing# 340# R# 600# mg# L R1 # of# chlorophenols#[131].#Interestingly,#for#lower#doses#(less#than#50#mg#L R1 #of#O3#consumed),# an# increase# in# total# PAH# concentration# has# been# observed.# This# has# been# attributed# to# the# better# extraction# efficiency# of# PAHs# for# analysis,# due# to# the# release# of# PAHs# entrapped#in#humic#substances#after#a#mild#ozonation#[130].# The# NAP# removal# in# Brij# 30# (B30)# containing# solutions# by# an# ozone# process# has# also# been#investigated#[132].#It#has#been#observed#that#an#increase#in#B30#concentration#(in# the#range#100#-#1000#mg#L R1 )#strongly#decreases#NAP#removal#efficiency.#
#compared#to#conventional#contactors#[132].# As#only#few#authors#have#studied#the#use#of#ozone#processes#for#the#treatment#of#SW/SF# solutions,#there#is#a#lack#of#data#on#the#influence#of#operating#conditions#and#nature#of# SW/SF#solutions.# # # # # # Chapter 1 53# 3.4.#Electrochemical#processes# 3.4.1.#General#considerations# In#electrochemical#processes,#the#application#of#an#electric#current#or#potential#between# two#electrodes#in#an#electrochemical#reactor#induces#electron#transfer#(redox)#reactions# resulting# in# direct# or# indirect# destruction# of# organic# compounds# [133-136].# Different# mechanisms#are#involved#according#to#operating#conditions#
.# Direct# electrolysis# results# from# electron# exchange# between# organic# pollutants# and# the# electrode#surface#without#involvement#of#other#substances.#This#is#theoretically#possible# in#the#potential#region#of#water#stability#(low#potential).#However,#adsorption#of#organic# compounds# onto# the# anode# material# and# formation# of# a# polymer# layer# on# the# anode# surface# can# lead# to# the# deactivation# of# the# anode# (poisoning# effect)# [5].# The# anode# fouling# effect# is# avoided# by# performing# oxidation# in# the# potential# region# of# water# discharge# i.e.+ high# anodic# potentials.# In# this# case,# formation# of# heterogeneous# • OH# (M( ! OH),#M#being#the#anode#material)#from#oxidation#of#water#can#occur#at#the#surface#of# the# anode# material.# This# is# an# EAOP# named# as# anodic# oxidation# (AO)# process# [5].# Two# classes# of# anodes# are# distinguished# in# AO:# "active"# and# "nonRactive"# electrodes# [137].# Particularly,# anodes# with# high# oxygen# evolution# overpotential# (called# nonRactive# electrodes)# allow# the# accumulation# of# large# amounts# of# physisorbed# M( • OH)# at# the# anode#surface,#leading#to#the#complete#mineralization#of#organics#to#CO2#[5]#(Eq.#5).## ! + ! ! ! → ! !" ! • + ! ! + ! ! #########! (Eq.#5)# The# production# of# some# other# electrochemically# generated# redox# reagents# can# simultaneously#occur#with#the#generation#of#M( • OH).#This#can#come#from#the#oxidation# of# compounds# used# as# electrolyte.# For# example,# active# chlorine# species# (Cl2,# HOCl,# ClO R # and# oxychloro# species# formed# by# oxidation# of# Cl -# on# the# anode# surface)# are# the# most# traditional# ones# used# [140,141].# It# is# named# mediated# oxidation.# However,# chlorinated# organic#compounds#can#also#be#produced,#leading#to#the#increase#of#wastewater#toxicity# [142].# Indirect# electrolysis# can# also# occur# through# production# of# ozone,# persulfate,# percarbonate,#perphosphate#[143-145].#
Electrochemistry# can# be# combined# with# Fenton's# chemistry;# this# has# been# extensively# studied# during# the# last# decades# [44,46].# The# very# popular# EAOP# called# electroRFenton# β-CD (10) HPCD (10) RHA (10) humic substances (10) Aerobic treatment. Pure culture of PAHdegrading bacteria, Sphingomonas sp. AJ1 (10 8 CFU mL CFU mL -1 ) PYR ( 50) None 24 w < 5

Chapter 1 54# (EF)# allows# avoiding# the# main# drawbacks# of# the# classical# Fenton# process,# i.e.# reagent's# cost,# waste# reactions# and# sludge# formation# [138].# It# is# based# on# the# in+ situ# electrocatalytic#generation#of#the#Fenton's#reagent#(the#mixture#of#H2O2#and#iron#(II))#in# the#homogeneous#medium#[136].#H2O2#is#continuously#supplied#to#the#solution#from#the# twoRelectron#reduction#of#dissolved#O2#on#the#cathode,#as#follows#(Eq.#6):# ! !(!) + 2! ! + 2! ! → ! ! ! ! # (Eq.#6)# Oxygen#required#for#H2O2#production#can#be#partially#formed#at#the#anode#by#oxidation# of#water#(particularly#with#Pt#anode)#and/or#directly#injected#as#compressed#air#[136].# The#oxidation#power#of#H2O2#is#strongly#enhanced#in#acidic#medium#in#the#presence#of#a# catalytic# amount# of# Fe 2+ # ions# [136].# This# comes# from# the# production# of# • OH# via# the# Fenton# reaction# (Eq.# 3).# Ferric# iron# formed# by# this# reaction# is# then# reduced# at# the# cathode#[146]#(Eq.#7).# !" !! + ! ! → !" !! # (Eq.#7)# This#allows#catalyzing#efficiently#the#Fenton#reaction,#through#continuous#regeneration# of#ferrous#iron.#Thus,# • OH#are#continuously#produced#in#the#solution#to#be#treated#via#
during+the+treatment+of+SW/SF+solutions+by+EAOPs.+ # # Radical$species$ !H 2 O 2 ! Fe 2+ ! Direct$electro4oxida6on$ Anode& Cathode& Fe 3+ ! Power!supply! ! O 2 ! Cl A !,!SO 4 2A !(electrolyte)! H 2 O! organic!compounds! M( ! OH)$ ! OH$
• OH)# (Table#1.3).# Finally,#the#efficiency#of#electrochemical#processes#depends#on#the#experimental#design# of# the# electrolytic# cell.# This# parameter# is# difficult# to# compare# between# the# different# research#groups.# # ! Nature)and)dose)of)the)electrolyte) Nature# and# concentration# of# electrolyte# is# of# great# importance.# It# has# been# shown# that# the# addition# of# Na2SO4# is# required# to# reduce# energy# consumption# and# treatment# costs# [156].# Moreover,# the# increase# Na2SO4# concentration# up# to# 0.1# M# improved# PAH# degradation# rates# [158].# The# effectiveness# of# electrochemical# oxidation# is# often# influenced#
[177] HPCD ( 10 ,aqueous,phase,partition,coefficient,of,the,target,pollutant.,I,is,the, equilibrium,between,the,hemi>micellar,layer,around,the,bacteria,cells,and,micelles,in,the, aqueous,phase.,II,is,the,equilibrium,between,pollutants,solubilized,in,hemi>micelles,around, the,bacteria,cells,and,micelles,in,the,aqueous,phase Extracting agent µ max (h -1 ) B30 (300 mg L -1 ) 0.32 B30 (1300 mg L -1 ) 0.08 B35 (300 mg L -1 ) < 0.02 TX100 (300 mg L -1 ) 0.32

! !" !" = - 1 ! ! !"# ⋅ ! 1 + ! ! ! + ! 1 + ! ! -!# (Eq.#8)# !" !" = ! !"# ⋅ ! 1 + ! ! ! + ! 1 + ! ! -!"# (Eq.#9)# where# µmax# is# the# maximum# substrate# utilization# rate;# S# is# the# concentration# of# target# substrate#(HOC);#Ks#is#the#halfEsaturation#constant;#X#is#the#biomass#concentration;#Y#is# the# yield# coefficient# (mass#
K s (mg L -
Triton N 101 (300 mg L -1 ) 0.34 1 "α"comes"from"the"expression"of" "="α.K p "with"K p "="C/C m "(C:"aqueous"phase"solute"concentration;"C m :"micelle"phase"solute"concentration)."α"is"a"fitted"parameter"that" characterizes"availability"of"micellar"phenanthrene"for"transport"into"actively"growing"cells."

!! = (1 - ! ! ! ! ×! ! )×100# (Eq.#10)# with,# ! ! = ! ! ! !" × ! ! ! ! # (

4.4.$Adsorption$processes$

Adsorption# processes# recently# received# great# attention,# due# to# promising# results# obtained# for# EA# recovery# [18].# Activated# carbon# is# the# most# widespread# sorbent# material#used#(Table # 1 Phenanthrene; 2,8,14,15 117"

! = ! ! !",! ! !,! × ! !,!" ! !",!" # (Eq.#12)# whereby# CSM,j0 is# the# concentration# of# the# target# pollutant# sorbed# onto# the# sorbent# material#(mg#g G1 ),0Cl,j0is#the#concentration#of#the#target#pollutant#in#the#liquid#phase#(mg# L G1 ),0 Cl,SA0 is# the# concentration# of# EA# in# the# liquid# phase# (g# L G1 )# and# CSM,SA0 is# the# concentration#of#EA#onto#the#sorbent#material#(g#g G1

2.3.(Particle(size(separation(

Wet" sieving" was" performed" for" particle" size" separation" [31]." Three" fractions" were" analyzed:" (i)" <63" µm" (fine" fraction," silt" and" clay)," (ii)" 63H200" µm" (fine" sand)" and"""""""""""" (iii)"200H2000"µm"(medium"to"coarse"sand)."The"duration"of"wet"sieving"and"volume"of" water" used" were" minimized" (ratio" soil:water" <1:3)" in" order" to" limit" the" loss" of" low" molecular"weight"PAHs."Particle"size"separation"on"the"soil"VS"was"not"performed"due"to" limited"amount"of"sample"available." "

2.4.(Optical(evaluation(

Soil"particles"of"various"samples"(initial"soil,"fully"oxidized"soil,"acetoneHtreated"soil"and" the"different"granulometric"fractions)"were"optically"inspected"using"a"stereomicroscope" (Carl" Zeiss," Stemi" DRC," Germany)" with" digital" camera" (Carl" Zeiss," AxioCam" ERc" 5s," Germany)" (total" magnification" of" 10H20" fold)." The" nature" of" the" particles" was" assessed" according" to" their" respective" size," color" and" shape." Black" particles" (BPs)" (i.e." particles" identified"as"either"solid"aggregates"of"resinified"and"weathered"tar"oil"(RWTO)"or"wood," coke" and" coalHlike" materials)" were" then" manually" separated" with" tweezers" from" the" sand"fraction." "

2.5.(Total(organic(carbon((TOC)(and(black(carbon(analysis(

Analyses"were"performed"using"a"combustion"furnace"(Ströhlein"Instruments,"Germany)" coupled" with" an" infrared" detector" (Seifert" Laborgeräte," C/S" max," Germany)." TOC" was" obtained" from" the" analysis" of" initial" soil" samples," whereas" BC" was" analyzed" after" oxidation"at"375"°C"of"the"nonHBC"materials" [START_REF] Khalil | Role" of" Weathered" Coal" Tar" Pitch" in" the" Partitioning" of" Polycyclic" Aromatic" Hydrocarbons" in" Manufactured" Gas" Plant" Site" Sediments[END_REF]."TOC"and"BC"content"in"Rositz"and"VS" soils"were"not"analyzed"due"to"limited"amount"of"sample"available." !

2.6.(PAH(extraction(and(analysis.(

PAH"extraction"from"soil"was"performed"following"the"method"of"Eschenbach"et"al." [37]" based"on"two"successive"steps,"including"an"organic"solvent"extraction"and"a"methanolic"

Chapter 2

118"

hydrolysis" (saponification)." Briefly," organic" solvent" extraction" was" performed" using""" 0.5"H"3"g"of"soil"mixed"with"3"mL"ethylacetate"(HPLC"grade)"into"10"mL"glass"Hugate"tube" sealed" with" screw" caps" (Schott" Duran," US)" and" ultrasonicating" the" mixture" for" 30" min" (Bandelin," Sonrex" Super," Germany)." After" centrifugation" of" the" slurry" (3500" rpm,"

15"min)," the" extract" was" sampled" for" analysis" of" its" PAH" content." Then," methanolic" hydrolysis" was" performed" using" saponification" leach" (2.8" mL" methanol" (HPLC" grade)," 0.2"mL"2"N"KOH)"and"incubating"the"samples"at"95"°C"for"1"h."Samples"were"centrifuged,"

an"aliquot"of"the"supernatant"was"pipetted"and"PAHs"were"extracted"by"means"of"three" successive" extractions" with" 1" mL" hexane." PAHs" were" quantified" using" a" gas" chromatograph" (7890A," Agilent" Technologies)" equipped" with" a" BPX5" column"""""""""""""""" (30"m"×"0.25"mm"id,"0.25"μm"film,"SGE"Analytical"Science,"Melbourne,"Australia)"coupled" to" a" quadrupole" mass" spectrometer" (5975C," Agilent" Technologies)." The" GC" oven" temperature" was" programmed" as" follows:" initial" 40" °C," hold" for" 2" min," then" heat" to" 180"°C"at"40"°C"min H1 ,"2Hmin"hold,"heat"to"240"°C"at"5"°C"min H1 ,"2Hmin"hold"and"heat"to"a" final"temperature"of"300"°C"at"15"°C"min H1 ,"5Hmin"hold,"with"a"helium"flow"of"1.5"mL"min H1 "

The" injector" was" set" to" 280" °C." The" mass" spectrometer" was" operated" in" the" electron" impact"ionization"mode"at"70"eV."Concentration"of"the"16"USEPA"PAH"was"obtained"by" means" of" the" internal" standard" method," using" deuterated" phenanthrene" and" chrysene" from" Sigma" Aldrich" as" internal" standard." Total" PAH" concentration" in" soil" samples" was" calculated" from" the" analysis" of" both" organic" solvent" extraction" and" methanolic" hydrolysis." All" soil" samples" were" analyzed" in" triplicate," allowing" the" calculation" of" standard"deviations"for"the"PAH"concentration"of"each"soil"sample." "

2.7.(Enrichment(factors(

Enrichment"factor"(EFS;f;i)"of"the"compound"S"(i.e."PAH,"TOC"or"BC)"in"the"fraction"f"(BPs"

or"the"different"granulometric"fractions)"of"the"soil"i"was"calculated"as"follows:""

!" !;!;! = ! [!] !;! [!] ! " (Eq."1)" Chapter 2
119"

whereby"[S]f;i"is"the"concentration"of"the"compound"S"in"the"fraction"f"of"the"soil"i"and"[S]i" is"the"concentration"of"the"compound"S"in"the"total"soil"i." "

2.8.(Selective(separation(procedure(

A" simple" procedure" was" proposed" in" order" to" test" the" possibility" of" developing" a"

selective" separation" process" for" the" most" contaminated" fraction." All" particles" were" suspended"in"water"(ratio"soil:water"of"1:2)"by"agitation"on"a"rotary"flatbed"shaker."The" agitation" was" then" stopped" and" particles" settled" according" to" their" respective" settling" velocity."The"procedure"was"applied"to"the"total"soil"as"well"as"to"different"granulometric" fractions."LowHdensity"BPs"in"the"sand"fraction"allowed"the"formation"of"an"upper"black" layer."The"supernatant"was"discarded;"the"upper"layer"was"carefully"removed"manually,"

weighted" and" analyzed" for" its" PAH" content." Resuspension" and" sedimentation" were" repeated" with" the" remaining" lower" layer." Once" again," the" two" different" layers" were" manually"separated,"weighted"and"analyzed"for"their"respective"PAH"contents."

" "

Chapter 2 120"

3.(Results(

3.1.(Identification(of(black(particles(

At"first"sight,"a"historically"tar"oil"polluted"soil"often"does"not"show"visual"evidence"of"its" contamination," e.g." the" untreated" brown" soil" VS" shown" in" Figure " 2.1" A1." However,"

adding"several"drops"of"acetone"to"the"parent"soil"material"causes"a"black"color"to"appear" on" some" particles" from" solubilization" of" residual" resinified" and" weathered" tar" oil" (RWTO;"Figure"2.1"A2)."The"full"oxidation"method"for"brown"humic"matter"qualitatively"

indicates" the" presence" of" solidHstate" BC" materials" in" the" white" or" glassy" solid" mineral" phase" (Figure"2.1"A3)."Similarly,"wet"sieving"of"the"soil"IdF"allowed"many"distinct"BPs"to" appear,"mainly"in"sand"fractions"(63H200"and"200H2000"μm)"(Figure "2.1"B)," due" to" the" removal"of"fine"materials"adhering"on"the"surface"of"sand"particles."

Particular" consideration" was" given" to" the" identification" of" BPs" by" stereomicroscopic" analysis,"resulting"in"Figure "2.1"CHF:"(i)"coalHlike"particles,"(ii)"porous"materials"such"as" coke"particles,"(iii)"glassy"slag"particles,"(iv)"solid"aggregates"of"RWTO,"often"mixed"with" sand,"silt,"clay"or"natural"soil"organic"matter."Various"other"types"of"BPs"observed,"such"

as" woodHlike" particles," are" given" in" Figure " 2.2." Based" upon" these" analyses," BPs" were" divided" into" two" main" classes:" RWTO" particles" and" wood/coke/coalHlike" particles." BPs"

were" observed" in" all" 6" soils" analyzed," as" shown" for" the" 63H200" μm" fractions" in" Figure "   2.3;"however,"differences"were"observed"in"terms"of"amount"and"nature."A"lower"amount" of" BPs" was" observed" in" the" Sobeslav" and" NoF" soils." Many" woodHlike" materials" were" identified" in" the" Sobeslav" soil," while" mainly" RWTO" particles" were" identified" in" NoF." A" large"variety"of"coalH"and"cokeHlike"materials"as"well"as"RWTO"aggregates"were"observed" in"the"Michle,"VS,"Rositz"and"IdF"soils." 124"

3.2.(Role(of(black(particles(in(PAH(distribution(for(aged(tar(oil/contaminated(soils(

BPs"were"manually"separated"from"the"sand"fraction"of"each"soil"and"analyzed"for"their"

PAH"content" (Figure"2.3)."The"enrichment"factor"for"the"sum"of"the"16"USEPA"PAHs"in"

BPs" was" 10," 10," 6," 6," 3" and" 2" for" the" Michle," Rositz," IdF," NoF," VS" and" Sobeslav" soils," respectively." A" slight" but" significant" higher" enrichment" of" the" heaviest" PAHs" was" observed"in"BPs,"as"shown"by"the"statistical"analysis"in"Supporting"Information" (Figure" 2.4)."The"patterns"of"16"USEPA"PAHs"distributions"were"also"different"between"the"sites."

While"the"full"PAH"spectrum"was"observed"in"the"IdF,"Rositz"and"VS"soils,"the"other"soils" contained"a"lower"amount"of"heavy"PAHs." BP;BP;-

Chapter 2
125" PAH"distribution"within"the"granulometric"fractions"<63,"63H200"and"200H2000"μm"was" then" investigated" (Figure" 2.5" A)." The" fraction" of" PAH" in" the" sand" fraction" (>63" μm)"

amounted"to"86,"71,"66,"53"and"42%"of"the"total"PAH"content"for"the"Rositz,"Michle,"IdF,"

Sobeslav"and"NoF"soils,"respectively."

TOC" and" BC" contents" of" bulk" soils" and" of" the" various" granulometric" fractions" were" determined" (see" Table" 2.1)." Good" linear" correlation" (factor" 1.02;" R 2 " =" 0.90)" was" observed" between" PAH" and" TOC" enrichment" factors" within" the" various" granulometric" fractions." Similar" correlation" was" observed" between" PAH" and" BC" enrichment" factor" (factor"1.00;"R 2 "="0.86)"( Figure and-NoF,-according-to-granulometric-fractions.-VS-and-Rositz-were-not-analyzed.-Tot:-totalsoil;-2000:-20092000-µm;-200:-639200-

3.3.(Implication(for(remediation(actions(-(New(treatment(strategy(

For"assessing"potential"treatment"options,"a"simple"BPHseparation"technique"was"tested" based"upon"the"differences"of"bulk"density"and"settling"velocity."IdF"was"selected"as"the" model" soil" due" to" the" high" amount" of" PAHs" in" its" sand" fraction" and" the" observation" of" nearly"all"BP"types."Unfortunately,"no"selective"separation"was"achieved"for"the"total"soil" and" the" fine" fraction," but" the" application" of" the" procedure" to" various" sand" fractions" allowed"the"formation"of"a"visible"black"upper"layer"representing"10"to"25%"of"the"total" height"and"containing"a"greater"amount"of"BPs"and"PAHs" (Figure"2.6)."Manual"separation" of" the" upper" layer" resulted" in" the" following" order" of" separation" effectiveness" (i.e." ratio" between"the" percentage"of"PAHs"removed"and"the"percentage"of"soil"removed)"for"the" most"contaminated"fraction:"63H200"μm">"200H2000"μm">"63H2000"μm."For"example,"the" PAH" concentration" in" the" upper" layer" of" the" 63H200" μm" fraction" was" 9.9" times" higher" than" in" the" residual" fraction." Thus," 76%" of" PAHs" contained" in" this" fraction" was" recovered," while" only" 24%" of" the" weight" of" this" soil" fraction" was" removed" (separation" effectiveness"="3.2)." Various" tarHoilHcontaminated" soils" with" a" wide" range" of" properties" were" analyzed,"

including" contaminations" by" raw" tar" oils" (full" PAH" spectrum)" and" specific" tar" oil" products" or" distillates" such" as" creosote," wood" impregnation" products" or" middleH distillates."However,"these"soils"are"obviously"characterized"by"the"absence"of"free"tar"oil" phases."Only"RWTO"and"wood/coke/coalHlike"particles"were"identified,"resulting"in"the" accumulation"of"PAHs"in"the"sand"fraction"and"mostly"exclusive"association"of"BPs"and"

PAHs" in" these" aged" tar" oilHcontaminated" soils." The" nature" and" amount" of" BPs" in" a" soil" thus"strongly"depend"on"the"contamination"history"at"the"site,"leading"to"impacts"on"the" characteristics" of" the" contamination" that" are" different" from" what" was" previously" considered."The"following"discussion"aims"at"explaining"these"results"and"emphasizing" their" implications" for" remediation" actions." Based" upon" the" present" results," a" new" treatment"approach"for"such"contaminated"soils"was"proposed"and"tested."" TarHoil"contaminations"are"complex"because"the"industrial"history"of"each"site"is"unique."

For" example," tar" oil" residues" were" often" dumped" in" open" pits" and" later" solidified" with" other"waste"materials"present"at"these"sites,"e.g."coal"powders,"coke"particles,"and"ashes" [38]." These" particles" were" observed" in" sand" fractions" of" all" contaminated" soils" studied"

( Figures" 3.1," 3.2" and" 3.3)." Moreover," the" BC/TOC" ratios" for" the" Michle" (0.76),"

Sobeslav"(0.32)," IdF" (0.44)" and" NoF" (0.30)" soils" were" high," i.e." similar" or" greater" than" values"observed"for"fireHimpacted"soils"(0.30"-"0.45)" [26]."This"is"related"to"the"nature"of" these"carbonaceous"materials"being"dumped"and"spilled."

Tar" oil" weathering" and" resinification," leading" to" solid" aggregate" formation," is" a" major" phenomenon"which"must"be"considered"when"describing"real"historically"contaminated" sites"and"assessing"bioavailable"fractions" [39]."Pure"WRTO"particles"and"various"mixed" aggregates"with"native"soil"organic"matter"or"mineral"particles"were"visualized"(Figure "   2.1" F" and" Figure" 2.2" BHG)." Weathering" of" tar" oil" from" a" NAPL" to" a" solid" phase" can" be" attributed" to" various" mechanisms." Luthy" et" al." [20]" were" the" first" to" report" that" shortH term"experiments"with"fresh"coal"tar"may"not"accurately"reflect"field"conditions"due"to"

Chapter 2 130"
the"formation"of"a"viscous"film"at"an"undisturbed"coal"tar"oilHwater"interface"after"only"

3"days." This" was" identified" as" an" interaction" phase," embedding" water" into" amphiphilic" molecules" of" the" interface." Interaction" between" water" and" tar" oil" compounds" was" reported" to" lead" to" the" formation" of" highly" viscous" phase" [40]." This" formation" of" solidified" films" could" also" result" from" the" adsorption" of" high" molecular" weight" compounds" at" the" interface," as" reported" for" crudeHoil" /" water" systems" [20]. " However," this"process"may"also"be"accelerated"by"enrichment"of"amphiphilic"molecules"from"soil" organic" matter" (e.g." from" microbial" lipids)" at" the" oil" phase" /" water" interface" and" polymerization" of" organic" compounds" by" oxidative" coupling" [START_REF] Paul | Soil"Biochemistry[END_REF]," finally" resulting" in" resinification" of" the" interface." According" to" Fick´s" 1 st " law" [40]," the" diffusion" over" this" rigid" interface" (Eq." 2" and" 3)" mostly" depends" on" the" viscosity" h" of" the" interface" layer," since"all"the"other"parameters"including"the"gradient"are"moreHorHless"similar."

" ! !"# = ! !" !" = ! -! • ! • !" !" !!!" (Eq."2)" " ! = !•! !!•!!!•!!!•!! !"#$ !!" "(Eq."3)"
where" JPAH" =" flux" of" PAH," n-=" amount" of" PAH;" t" =" time," D" =" diffusion" constant," A" ="

interface"area,"c"="concentration,"x"="thickness"of"the"interface,"k"="Boltzmann"constant,"T" ="temperature,"h"="viscosity,"rRWTO"="radius"of"RWTO"particle."

The"following"model"can"describe"the"mass"transfer"processes."Interfaces"of"increasing" viscosity" result" in" two" massHtransferHlimiting" interface" layers:" one" towards" the" water"

phase"and"one"towards"the"oil"phase"of"lower"(original)"viscosity" (Figure"2.7)."This"leads" to" PAH" concentration" shifts" at" each" interface," finally" resulting" in" much" lower" mass" transfer" in" comparison" to" an" interface" of" a" tar" oil" drop" with" homogeneous" viscosity."

Furthermore,"this"also"results"in"behavioral"differences"between"externally"added"PAHs" and"the"aged"PAH"matrix"in"experiments"with"real"contaminated"sites,"e.g."when"spiked"

with"radiolabeled"PAHs.""" Increasing"extension"of"the"resinified"interface"towards"the"center"of"the"oil"drop"finally" results"in"the"formation"of"(semiH)solid"particles"with"very"low"mass"transfer;"this"effect" was"technically"applied"for"caulking"wooden"ship"planks"with"pine"tar"oil."At"later"stages," the"depletion"in"the"NAPL"of"the"most"soluble"and"biodegradable"compounds"may"lead" to"the"precipitation"of"a"portion"of"the"coal"tar,"due"to"the"increase"of"the"mole"fraction"of" barely" soluble" compounds" above" their" solubility" limit" [42,[START_REF] Peters | Multicomponent" NAPL" Solidification" Thermodynamics[END_REF]." This" could" explain" the" higher"enrichment"of"heavy"PAHs"in"BPs" (Figure"2.4),"compared"to"respective"bulk"soils," due" to" their" lower" solubility" limit," in" particular" in" WRTO" [44]." Higher" shifts" towards" heavy"PAHs"in"the"PAH"pattern"distribution"would"be"observed"compared"to"the"initial" tar"oil,"since"light"PAHs"are"more"easily"biodegraded" [45]."Overall,"these"processes"lead" to"coal"tar"ageing"and"formation"of"organic"particles"with"a"grain"size"similar"to"that"of" sand"materials" [22]."These"particles"contain"large"amounts"of"PAHs,"which"are"integral"to" the" material" and" present" throughout" the" interior" [START_REF] Khalil | Role" of" Weathered" Coal" Tar" Pitch" in" the" Partitioning" of" Polycyclic" Aromatic" Hydrocarbons" in" Manufactured" Gas" Plant" Site" Sediments[END_REF]." This" may" explain" the" high" PAH"

140"

"

! Chapter 3
145# management#of#the#NOM#is#also#crucial#for#the#treatment#strategy#combining#EAOPs#and# membrane#processes#because#it#is#the#main#responsible#of#membrane#fouling# [31,[START_REF] Khalil | Role" of" Weathered" Coal" Tar" Pitch" in" the" Partitioning" of" Polycyclic" Aromatic" Hydrocarbons" in" Manufactured" Gas" Plant" Site" Sediments[END_REF].## Hydroxyl# radicals# react# with# a# wide# spectrum# of# NOM# of# both# hydrophobic# and# hydrophilic# character.# Rate# constants# for# reactions# with# NOM# have# been# measured# at### 1-5#×#10 8 # M -1 # s -1 # [33].# One# of# the# most# popular# EAOPs# is# the# anodic# oxidation# (AO)# process,#where#organic#compounds#directly#react#with#heterogeneous#hydroxyl#radicals# M( ! OH)# [34]#formed#by#oxidation#of#water#at#the#surface#of#anodes#(M)#with#high#oxygen# overpotential# [START_REF] Benhabib | Characteristics"of"a"solid"coal"tar"sampled"from"a" contaminated" soil" and" of" the" organics" transferred" into" water[END_REF][START_REF] Kästner | Formation"of"bound"residues"during" microbial"degradation"of"[14C]anthracene"in"soil[END_REF]#(Eq.#1).#Particularly,#boron#doped#diamond#(BDD)#anode#have#very# high#catalytic#activity#and#allows#producing#large#amount#of# ! OH.##

M + H ! O → M OH ! • + ! H ! + e ! ## (Eq.#1)# The#other#popular#EAOP#is#the#electroMFenton#(EF)#process,#in#which# ! OH#are#produced# homogeneously# in# the# bulk# of# treated# solution# from# the# electrochemically# generated# Fenton's# reagent# (mixture# of# H2O2# and# Fe 2+ )# [37-40]# (Eq.# 2).# H2O2# is# in# situ# electrogenerated#at#the#cathode#from#the#twoMelectrons#reduction#of#dissolved#O2#(Eq.#3)# [17,40].#A#catalytic#amount#of#ferrous#iron#salt#is#sufficient#to#turn#up#the#process,#due#to#
the#catalytic#electroMregeneration#of#ferrous#iron#at#the#cathode#(Eq.#4)# [START_REF] Paul | Soil"Biochemistry[END_REF][42][START_REF] Peters | Multicomponent" NAPL" Solidification" Thermodynamics[END_REF].#

Fe !! + H ! O ! → Fe !! + OH • + OH ! #############(k#=#63#M M1 #s M1 )## (Eq.#2)# O ! + 2H ! + 2e ! → H ! O ! !!!!!!!!!# (Eq.#3)# Fe !! + e ! → Fe !! !!!!!!!!!!# (Eq.#4)#
These#homogeneous#and#heterogeneous# ! OH#can#then#react#with#the#organic#matter#(R)#

and#oxidize#it#until#ultimate#oxidation#state#is#reached,#i.e.,#mineralization#(Eq.#5):# 149# Iron#concentration#was#analyzed#using#a#Perkin#Elmer#Optima#8300#ion#coupled#plasma# optical# emission# spectrometer# (ICPMOES).# Some# samples# were# analyzed# after# filtration# through#0.7#μm#glass#fiber#filters,#while#the#total#iron#concentration#was#analyzed#after# mineralization# of# samples# by# addition# of# hydrogen# peroxide# and# nitric# acid# in# a# water# bath#(95°C).# #

R + OH/M OH ! • • → M + CO ! + H ! O! + !mineral!ions ## (Eq.#5)# To#the#best#of#our#knowledge,#it#is#the#first#time#that#

2.5.(Mathematical(modeling(

A#model#was#developed#in#order#to#monitor#the#evolution#of#TOC#in#the#solution#during# various# EAOPs.# The# software# Aquasim# was# used# [48].# Both# sorption# and# oxidation# processes#were#considered.#

First,# it# was# assumed# that# organics# degradation# in# the# electrochemical# cell# originates# only# from# reaction# with# ! OH# (either# ! OH# from# homogeneous# catalysis# during# EF# or# M( ! OH)# from# heterogeneous# catalysis# at# the# surface# of# BDD# anode),# a# strong# oxidizing# agent# and# nonMselective# reagent# with# a# standard# reduction# potential# of####################### E°( ! OH#/H2O)#=#2.8#V/SHE#[21].#
Then,# the# use# of# the# highly# porous# CS# cathode# led# to# the# adsorption# of# HAs# onto# its# surface.#The#kinetics#of#sorption#from#a#solution#onto#an#adsorbent#was#well#explored#by#

Azizian# [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF].# The# author# showed# that# the# sorption# process# obeys# the# pseudoMsecondM

order#model,#provided#that#the#initial#concentration#of#solute#is#not#too#high#compared# to#the#active#surface#area#of#the#sorbent#material#(Eq.#6),# d! dt = !(! ! -!) ! # (Eq.#6)#
where# q# and# qe# are# the# milligrams# of# HAs# sorbed# per# gram# of# sorbent# at# any# time# and# equilibrium,# respectively,# and# k# is# the# pseudoMsecondMorder# rate# constant# of# sorption.# One#can#also#rewrite#Eq.#6#as#follows,#

d[HA !"# ] dt = ! ! ( HA !"# !" -[HA !"# ]) ! # (Eq.#7)# Chapter 3 150# where#k'#is#the#observed#pseudoMsecondMorder#rate#constant#((mg#L M1 ) M1 #h M1 )#and#[HAads]#
and#[HAads]eq#are#the#milligrams#of#carbon#of#HAs#sorbed#per#litre#of#solution#(mg#L M1 )#at# any#time#and#equilibrium,#respectively;#i.e.,# Agreement# (IoA)# (Eq.# 13)# [50][51][START_REF] Hinds | Aerosol"technology[END_REF].# Unknown# parameters# were# determined# by# optimizing#these#three#criteria.#

HA !"# = ! ! ! ! !"# !# ###(Eq.#8)# where# mc# is# the# mass# of# sorbent# (g),# Vsol#(L)# is# the# volume# of# the# solution# and# η# is# the# mass#fraction#of#carbon#in#HA#molecules.# Azizian# [49]# also# reported# that# the# pseudoMsecondMorder# rate# constant# of# sorption# is# a# function#of#the#initial#concentration#of#solute.#During#electrolysis,#oxidation#of#organics# modifies# the# total# HAs# concentration.# Thus,# it# was# proposed# to# express# k'# as# a# simple# function#of#the#total#HA#concentration,#as#follows,# !′ = ! !"# [HA] !"! # #(Eq.#9)# where#[HA]tot#is#the#sum#of#[
RMSE = ! (y ! -y ! ! ) ! ! !!! K # #(Eq.#11)# Chapter 3 151# ME = 1 -! (y ! -y ! ! ) ! ! !!! (y ! -! ! ) ! ! !!! # #(Eq.#12)# IoA = 1 -! (! ! -! ! ! ) ! ! !!! ( ! ! ! -! ! + ! ! -! ! ) ! ! !!! ! #(Eq.#13)# where#K#is#the#number#of#observed#values,#! ! #is#the#single#numerically#simulated#value,# ! ! ! #is# the# corresponding# experimentally# observed# value,# ! ! #is# the# average# of#

Experimental results

The# evolution# of# TOCsol# and# TOCads# during# the# EFMPt# process# at# 300# mA# is# depicted# in#

k min_BDD k ads k HA k HA_ads k HABP (h -1 ) (h -1 ) (h -1 ) (h -1 ) (h -1 )
AO-SS 0.17

1.(Introduction(

Surfactants%are%amphiphilic%molecules%made%of%a%hydrophilic%head%and%hydrophobic%tail% mainly% characterized% by% their% critical% micelle% concentration% (CMC)% and% hydrophilicO lipophilic% balance% (HLB)% [1].% At% concentration% C<CMC,% surfactant% monomers% lower% the% surface% tension% of% a% solution% and% it% is% only% at% C>CMC% that% surfactant% aggregates% called% micelles% are% formed% [2].% Micelles% create% a% hydrophobic% space% in% which% hydrophobic% organic% compounds% (HOCs)% are% entrapped,% thus% leading% to% strong% HOCs% solubility% enhancement% [3,4].% HOCs% partitioning% between% the% micellar% and% aqueous% phase% is% determined%by%the%micellar%/%aqueous%phase%partitioning%coefficient%Km%(Eq.%1)% [3],%which% usually%follows%similar%trend%than%the%octanol%/%water%partitioning%coefficient%Kow.%Many% surfactants% with% different% chemical% structures% have% been% developed.% They% are% divided% into% four% main% categories,% including% anionic,% cationic,% amphoteric% and% nonOionic% surfactants% and% their% toxicity% has% been% reported% to% be% strongly% dependent% on% their% chemical%structure% [5,6].%

! ! = ! ! ! ! % (Eq.%1)%
whereby% Xm% and% Xa% are% mole% fraction% of% target% pollutants% in% the% micellar% pseudoOphase% and%aqueous%phase,%respectively.% Surfactants% are% important% components% in% the% formulation% of% most% of% detergents% and% a% large% range% of% industrial% activities% (textile,% paint,% food,% pharmaceutical% and% pulpOpaper% industries)% also% requires% the% use% of% these% compounds% because% of% the% possibility% to% use% them% as% emulsifiers,% solubilizing% agents,% softeners,% lubricants,% wetting% agents,% dying% agents,%etc.%% [7].%Thus,%dozens%of%million%tons%of%surfactants%are%produced%every%year%and% they% are% among% the% most% widely% disseminated% xenobiotic% in% aquatic% environments% [8].% Therefore,% regulation% authorities% usually% impose% an% effective% treatment% of% surfactantO containing% industrial% wastewaters% [8].% Besides,% the% use% of% environmentally% friendly% surfactants% as% extracting% agent% in% chemically% enhanced% soil% washing% (SW)% and% soil% flushing%(SF)%processes%is%a%promising%treatment%strategy%for%the%removal%of%HOCs%from% contaminated%soils% [1,[9][10][11].%However,%this%generates%SW/SF%solutions%containing%large% amounts% of% soil% pollutants,% natural% soil% organic% matter% and% surfactants.% The% low%

Chapter 4 180 availability% of% pollutants% in% historically% contaminated% soils% requires% the% use% of% high% surfactant%concentration%and/or%implementation%of%several%successive%SW%steps% [9,12].% Thus,%the%main%drawback%of%SW/SF%processes%is%the%consumption%of%too%much%(costly)% surfactant.%Therefore,%an%optimal%treatment%of%SW/SF%solutions%aims%at%the%total%removal% of%target%HOCs%together%with%the%recovery%of%surfactants%for%reuse%of%the%SW/SF%solution% in%order%to%improve%the%costOeffectiveness%of%the%whole%process% [9,[13][14][15].%% Aerobic% biological% processes% are% the% most% common% treatment% strategy% for% surfactant% containing%wastewaters.%However,%such%treatment%is%sometimes%not%suitable%for%hardly% degradable%surfactants%or%when%strong%foaming%issues%occur% [8].%Therefore,%alternative% remediation%techniques%have%been%developed%such%as%coagulation%processes%(for%anionic% surfactants)% [8,16,17]% as% well% as% membrane% [18]% and% oxidation% processes% [19][20][21][22].%

Particularly,%anodic%oxidation%(AO)%is%a%promising%technique%since%it%can%lead%to%the%fast% and%total%mineralization%of%all%organic%compounds,%including%surfactants% [23][24][25][26][27][28][29][30][31].%For%the% treatment% of% SW/SF% solutions,% air% stripping% [18],% solvent% extraction% [START_REF] Khalil | Role" of" Weathered" Coal" Tar" Pitch" in" the" Partitioning" of" Polycyclic" Aromatic" Hydrocarbons" in" Manufactured" Gas" Plant" Site" Sediments[END_REF]% or% adsorption% processes% [33]%can%lead%to%the%selective%separation%of%target%HOCs%from%SW%solutions%but% only% few% studies% reported% the% implementation% of% degradation% processes% for% selective% degradation% of% target% pollutants% [9,14].% Selective% degradation% is% very% challenging% since% target%HOCs%are%entrapped%in%surfactant%micelles,%which%form%a%protective%environment% around%the%pollutant% [9,13,34].% This%study%focuses%on%the%use%of%an%electrochemical%advanced%oxidation%process,%i.e.%AO% process%using%boron%doped%diamond%(BDD)%anode%for%the%treatment%of%SW%solutions.%It%is% based% on% the% production% of% hydroxyl% radicals% BDD( • OH)% from% water% oxidation% on% the% surface%of%BDD%anode%(Eq.%2)% [23,29,[START_REF] Benhabib | Characteristics"of"a"solid"coal"tar"sampled"from"a" contaminated" soil" and" of" the" organics" transferred" into" water[END_REF][START_REF] Kästner | Formation"of"bound"residues"during" microbial"degradation"of"[14C]anthracene"in"soil[END_REF].%The% • OH%is%the%second%most%reactive%oxidant% species% [37],%which%is%also%characterized%by%a%very%short%lifetime.%Therefore,%a%thin%layer% of% BDD( • OH)% is% formed% on% the% BDD% surface;% the% BDD( • OH)% concentration% follows% an%% exponential%distribution%from%the%BDD%surface%up%to%few%nm/μm,%according%to%operating% conditions% [38,39].% The% amount% of% BDD( • OH)% generated% and% the% thickness% of% the% BDD( • OH)%layer%is%directly%dependent%on%the%current%intensity%applied%and%concentration% /%reactivity%of%organic%compounds%in%the%solution% [38,39].%Organic%pollutants%react%then% with% BDD( • OH)% either% under% mass% transport% or% current% intensity% control,% according% to% the% ratio% between% the% amount% of% BDD( • OH)% produced% and% concentration% of% organic% compounds% [START_REF] Benhabib | Characteristics"of"a"solid"coal"tar"sampled"from"a" contaminated" soil" and" of" the" organics" transferred" into" water[END_REF].% However,% recent% studies% on% the% treatment% of% SW% solutions% by% AO% Chapter 4

181 process%suggested%that%a%steric%hindrance%phenomenon%might%occur%for%the%oxidation%of% surfactant% micelles% on% the% surface% of% the% BDD% anode,% due% to% the% low% thickness% of% the% BDD( • OH)% layer% [34,40].% Degradation% of% organic% pollutants% during% AO% at% high% current% intensity% can% also% occur% by% mediated% oxidation,% e.g.% the% generation% of% strong% oxidant% species% such% as% persulfate% or% ozone% has% been% observed% to% promote% the% degradation% of% organic%compounds%in%the%bulk% [23,34,[START_REF] Kästner | Formation"of"bound"residues"during" microbial"degradation"of"[14C]anthracene"in"soil[END_REF][START_REF] Paul | Soil"Biochemistry[END_REF].%

BDD + H ! O → BDD OH ! • + H ! + e ! % (Eq.%2)%
In% the% present% study,% Tween ® % 80% (TW80)% was% chosen% as% model% nonOionic% surfactant% because% several% studies% reported% its% high% efficiency% for% the% removal% of% HOCs% from% contaminated% soils% [42,[START_REF] Peters | Multicomponent" NAPL" Solidification" Thermodynamics[END_REF].% Besides,% polycyclic% aromatic% hydrocarbons% (PAHs)% were% studied%as%target%pollutants%(by%using%either%phenanthrene%(PHE)%as%model%pollutant%or% real% SW% solutions)% since% soil% contamination% by% PAHs% is% a% major% environmental% issue.% Results% were% also% compared% with% the% use% of% pOhydroxybenzoic% acid% (HBA),% which% presents%a%much%higher%solubility%(36%mM)%than%PAHs%(for%example,%0.007%mM%for%PHE).% The% specific% objectives% of% this% study% are% to% investigate% for% the% first% time% (i)% the% mechanisms% of% surfactant% oxidation% during% AO,% which% strongly% depends% on% current% intensity% and% surfactant% concentration% and% (ii)% the% oxidation% mechanisms% of% HOCs% solubilized% in% surfactantOcontaining% solutions% in% order% to% provide% sound% recommendations% for% the% treatment% of% SW/SF% solutions,% including% very% promising% results% for% surfactant% recycling% and% SW% solution% reuse% using% a% soil% historically% contaminated%by%PAHs.% % % The% treatment% of% a% real% SW% solution% was% also% investigated.% The% soil% used% during% all% experiments% originates% from% a% historically% contaminated% site% (polluted% by% industrial% activities% of% bituminous% production).% SW% experiments% were% performed% on% the% sand% fraction% (>63% μm),% which% was% previously% identified% as% the% most% contaminated% and% less% treatable% fraction,% due% to% the% presence% of% large% amount% of% solid% particles% of% weathered% and% resinified% tar% oil% [45][46][47].% Four% PAHs% were% monitored% including% PHE,% anthracene% (ANT),% pyrene% (PYR)% and% fluoranthene% (FLUO).% The% total% amount% of% these% PAHs% in% the% soil% fraction% used% during% SW% experiments% was% determined% by% the% extraction% method% developed% by% Eschenbach% et% al.% [48].% It% contained% 78% mg% PHE% kg O1 ,% 36% mg% ANT% kg O1 ,% 117%mg% PYR% kg O1 % and% 75% mg% FLUO% kg O1 .% The% protocol% used% for% SW% experiments% was% similar%to%the%protocol%described%by%Mousset%et%al.% [12].%SW%was%performed%in%bottles%of% 2%L%filled%with%1.5%L%of%fresh%SW%solution%containing%5%mM%of%TW80.%The%ratio%soil/liquid% was% 10%.% The% contact% time% in% the% rotary% shaker% (20% rpm)% was% 24% h.% At% the% end% of% the% experiment,% the% SW% solution% was% allowed% to% settle% during% 2% h% and% then,% centrifuged% at% 3500% rpm% during% 15% min.% The% same% procedure% was% performed% for% investigation% of% the% Germany)%ensured%constant%current%supply%in%the%range%50%-%1000%mA.%All%experiments% with% single% compounds% and% binary% mixtures% (HBA/TW80% or% PHE/TW80)% were% performed%at%pH%3%by%using%H2SO4%for%pH%adjustment.%The%treatment%of%SW%solutions%was% performed%at%the%natural%pH%(synthetic%SW%solution:%5.5;%real%SW%solution:%7.2),%however% the% pH% rapidly% decreased% between% 3O4% during% the% treatment% due% to% the% formation% of% degradation% byOproducts% such% as% carboxylic% acids% [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF].% It% has% been% reported% that% the% efficiency% of% the% AO% process% does% not% depend% on% the% pH% of% the% solution% [27];% contradictory%results%have%also%been%reported%in%the%literature% [50] degradation(of(Tween ® 80((TW80)(and(phenanthrene((PHE)(and(mineralization(of(humic( acids((HA),(as(a(function(of(current(intensity((I)(during(anodic(oxidation( ([Na2SO4](=(0.05 (M;(V0(=(330(mL).( [56,57].% However,% in% the% case% of% a% SW% solution% containing% high% TW80% concentration,% the% large% amount% of% surfactant% led% to% the% higher% inhibitory% effect;% 768%mgC% L O1 % (1% mM)% decreased% the% apparent% rate% constant% of% PHE% degradation% by% a% factor% 10.% In% addition% to% the% BDD( • OH)% scavenging% effect,% TW80% micelles% form% a% protective% environment% for% PHE% and% reduce% the% availability% of% PHE% towards% BDD( • OH)% [9,13].% This% latter% phenomenon% was% further% emphasized% in% Figure% 4. (pseudo3first(order)(degradation(kinetics((kapp)(of(phenanthrene(([PHE]0(=(0.1(μM)(in (a( binary(mixture(phenanthrene3humic(acid(or(phenanthrene3Tween ® (80(treated(by(AO(at( 300(mA(([Na2SO4](=(0.05 (M;(V0(=(330(mL) ((1(mM(TW80(=(768(mgC(L 31 ).( (a( binary(mixture(treated(by(anodic(oxidation(at(1000(mA(([Na2SO4](=(0.05 (M;(V0(=(330(mL) (condition((C(=(7.5(μM)(by(competition(kinetics(method( using(HBA((0.1(mM)(as(standard(competitor,(during(treatment(by(AO(under(the(following( operating(conditions:(BDD(anode,(SS(cathode,([Na2SO4](=(0.05 (M;(V0(=(330(mL;(I(=(200(mA;( pH(3.(Error(bars(refer(to(triplicate(experiments.( Therefore,% this% study% also% investigated% the% evolution% of% the% degradation% of% organic% compounds%in%a%binary%mixture%target%molecule%/%TW80%for%TW80%concentrations%above% the%CMC.%Particularly,%the%selective%(or%preferential)%degradation%of%target%molecules%was% assessed%by%using%the%ratio%R%(Eq.%4),%defined%as%follows:% ! = ! !"" ! ! !"" !"!" % (Eq.%4)% where%! !"" ! %is% the% apparent% (pseudoOfirst% order)% rate% constant% of% the% degradation% of% a% target% molecule% X% (HBA% or% PHE)% and%! !!! !"!" %is% the% apparent% rate% constant% of% TW80% degradation.% Interestingly,%the%ratio%R%varied%between%0.43%and%10%by%using%HBA%as%target%molecule,% according%to%current%intensity%and%TW80%concentration%(Figures%4.5a%and%4.5b).% (M;(V0(=(330(mL). ((a):(ratio(R(between(the(apparent((pseudo3first( order)(degradation(kinetics((kapp)(of(HBA(([HBA]0(=(0.2(mM) (and(TW80,(as(a(function(of( TW80(concentration((AO(at(I(=(1000(mA). ((b):(ratio(R(between(kapp(of(HBA( ([HBA]0(=(0.2(mM) (and(TW80(([TW80]0(=(1(mM),(as(a(function(of(current(intensity.(((((((((( (c):(ratio(R(between(kapp(of(PHE(([PHE]0(=(0.14(mM)(and(TW80(([TW80]0(=(1(mM),(as (a( function(of(current(intensity.(Error(bars(refer(to(triplicate(experiments.( (concentration(are(calculated(from(the( model(of(Kapalka(et(al.([39](with([TW80](= (1(mM(and(different(current(intensities.( Also,% one% should% consider% that% mediated% oxidation% in% the% bulk% can% occur% during% AO.% Particularly,% at% high% current% intensity% (1000% mA),% it% was% observed% a% significant% higher% degradation% kinetic% of% TW80% by% using% Na2SO4% as% supporting% electrolyte,% compared% to% NaClO4% (Figure% 4.7).% This% might% be% related% to% the% generation% of% highly% oxidant% species% such%as%persulfates,%which%promoted%the%oxidation%of%TW80%micelles%in%the%bulk% [23,60].% This%phenomenon%was%not%observed%at%200%mA%because%low%current%intensity%does%not% allow% the% production% of% such% oxidant% species% at% a% sufficient% concentration.% Overall,% the% absence% of% mediated% oxidation% combined% to% the% steric% hindrance% phenomenon% can% explain% the% strong% decrease% of% degradation% kinetics% of% TW80% micelles% at% low% current% intensity.% (treatment(by(AO(at(200(mA(and( 1000(mA.(Error(bars(refer(to(triplicate(experiments.( Besides,% it% was% also% observed% that% the% ratio% R% depends% on% the% TW80% concentration.% At% 1000% mA,% experimental% results% showed% that% the% lower% the% TW80% concentration,% the% lower%the%ratio%R%(Figure%4.5a).%However,%the%decrease%of%the%TW80%concentration%led%to% the%increase%of%the%apparent%rate%constant%of%HBA%degradation,%due%to%a%lower%BDD( 1(M(or(5(M)(concentrations(during(treatment(of(the(synthetic(SW(solution(by(AO(at(50(mA( ([Na2SO4](=(0.05 (M;(V0(=(330(mL).(

2.(Materials(and(methods(

!!!! ! ! ! ! ! !!! ! ! !(a)!! !!!!!!HBA!/!TW80! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!!! !!! ! ! !(b)!! !!!!!!HBA!/!TW80! ! ! ! ! ! ! ! ! !!!!!!!!!! ! ! !! !!(c)!! !!!!!!!!PHE!/!
For% the% treatment% of% the% real% SW% solution,% lower% degradation% kinetics% of% target% PAHs% were%observed%compared%to%the%synthetic%SW%solution,%due%to%the%competition%of%a%large% range% of% dissolved% organic% compounds% as% well% as% fine% particles% from% the% clayOhumus% complex.% After% 23% h% of% treatment,% 83%,% 90%,% 77%% and% 75%% of% 0.014% mM% PHE,% 0.0031%mM% ANT,% 0.015% mM% PYR% and% 0.011% mM% FLUO% was% degraded,% respectively.% Furthermore,%the%extraction%capacity%of%the%SW%solution%after%23%h%of%treatment%was%only% 5%%lower%than%a%fresh%SW%solution%(Figure%4.9).%This%is%ascribed%to%the%low%degradation% of% TW80% as% well% as% possible% formation% of% TW80% oxidation% byOproducts% with% extracting% properties.% A%decrease%of%the%pH%around%3.8%was%observed%after%a%treatment%time%of%23%h,%due%to%the% production%of%oxidation%byOproducts%such%as%carboxylic%acids.%However,%the%reuse%of%the% treated%SW%solution%may%not%affect%the%pH%of%the%soil%since%a%real%soil%has%a%much%higher% buffer%capacity%than%the%reused%SW%solution% [12].%Moreover,%Trellu%et%al.% [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF]%observed% that%the%treatment%of%a%SW%solution%by%AO%leads%to%the%production%of%more%hydrophilic% and%more%biodegradable%byOproducts,%therefore,%intermediates%are%not%expected%to%affect% the%soil%microbial%activity% [12].% In%this%study,%one%SW%step%using%5%mM%of%TW80%only%removed%from%soil%24%%of%the%total% of%the%4%PAHs%analyzed%(Figure%4.9).%This%is%due%to%the%strong%sequestration%of%PAHs%in% solid% particles% of% weathered% and% resinified% tar% oil% [45][46][47].% Thus,% either% additional% SW% solution% steps% or% a% higher% TW80% concentration% would% be% required% to% reach% the% regulation%discharge%for%contaminated%soils.%This%is%the%reason%why%selective%oxidation%of% target%pollutants%at%low%current%intensity%is%an%attractive%treatment%strategy%for%recycling% the%SW%solution%for%required%additional%SW%steps.%Moreover,%it%has%been%widely%reported% in%the%literature%that%low%current%intensity%increases%treatment%times%but%reduces%energy% consumption% [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF]65];% 23% h% of% treatment% at% 50% mA% led% to% the% consumption% of% only% 13.2%kWh%m O3 .%By%comparison,%a%previous%study%reported%that%5%h%of%treatment%by%AO%at% 1000%mA%of%the%same%synthetic%SW%solution%than%the%one%used%in%this%study%(with%1%mM% TW80)%led%to%the%consumption%of%127%kWh%m O3 % [START_REF] Ghosh | ParticleHScale"Measurement"of"PAH"Aqueous"Equilibrium"Partitioning" in"Impacted"Sediments[END_REF].% contaminated(soil(of(a(fresh(SW(solution(containing(5(mM(of(Tween ® (80,(a(SW(solution( reused(after(treatment(by(anodic(oxidation((AO)(at(50(mA(during(23(h(and(a(SW(solution( reused(after(treatment(by(activated(carbon((AC)(at(1(g(L 31 ,(2(g(L 31 (or(3.5(g(L 31

LANGUAGES

• French: mother tongue.

• English: proficient user (oral and written).

• German: basic user.

PROJECT MANAGEMENT

• Design and planning of experimental procedures in collaboration with various research groups and private partners (AREVA). • Integration into 3 different international research teams during the doctoral thesis.

• Supervision of 2 research assistants (bachelor level, 3 months) and a Master's thesis (5 months). Mousset E., Pechaud Y., Huguenot D., van Hullebusch E.D., Esposito G., Oturan M.A., 2016. Removal of hydrophobic organic pollutants from soil washing/flushing solutions: A critical review. Journal of Hazardous Materials,306,

  3.!Implication!for!remediation!action!-!New!treatment!strategy! !!!!!!!!!!!Characteristics!of!aged!tar!oilFcontaminated!soils!and!role!of!black!particles! in!PAH!distribution!

  Removal!of!humic!acids!during!AOFCS!and!AOFSS!processes!!

  Degradation!kinetics!of!single!compounds! ! ! ! !!!!!!!!!!!!186! 3.2.!Inhibitory!effect!of!Tween ® !80!and!humic!acids!on!phenanthrene! degradation!Tween ® !80!degradation!kinetic!and!mechanism!during!the!AO!process!!!!189! 3.4.!Degradation!mechanism!of!organic!compounds!solubilized!in!Tween ® Application!-!Reuse!of!soil!washing!solutions!by!selective!degradation!of! target!pollutants!during!AO!at!low!current!intensity! ! ! !!!!!!!!!!!!195!3.6.!Comparison!with!selective!adsorption!on!activated!carbon!for!soil!washing! solution!treatment!and!reuse!

Figure' 1 . 2 .Figure' 1 . 4 .Figure' 1 . 7 .Figure' 1 . 8 .Figure' 1 . 9 .Figure' 2 . 2 .Figure' 2 . 3 .Figure' 2 . 4 .Figure' 2 . 5 :Figure' 2 . 6 .Figure' 2 . 7 .Figure' 3 . 1 .Figure' 3 . 2 .Figure' 3 . 4 .Figure' 3 . 5 .Figure' 3 . 6 .Figure' 4 . 1 .Figure' 4 . 2 .Figure' 4 . 3 .Figure' 4 . 4 .Figure' 4 . 5 !Figure' 4 . 6 .Figure' 4 . 7 .Figure' 4 . 9 .Figure' 5 . 1 .Figure' 5 . 3 .Figure' 5 . 4 .Figure' 5 . 5 !Figure' 5 . 6 .Figure' 6 . 1 .

 121417181922232425262731323435364142434445464749515354555661 Figure'1.!Structure!of!the!thesis.! ! ! ! ! ! ! ! 11!

Figure

  Figure!1.%Structure%of%the%thesis.!

  photo]Fenton),# ozonation,# electrochemical# processes,# biological# treatments# and# the# combination# of# advanced# oxidation# processes# (AOPs)# with# a# biological# treatment#have#been#investigated.#

Figure( 1 . 2 .

 12 Figure(1.2.#Surface'tension'and'hydrophobic'organic'compounds'(HOCs)'solubility'enhancement'factor'as'a'function'of'surfactant'concentration.' '

  .# Moreover,#surfactants#may#also#form#emulsions#with#high#viscosity#that#are#difficult#to# manage#and#remove.# There# are# four# major# surfactant# categories,# which# include# anionics# (such# as# sodium# dodecylsulfate# (SDS)# or# linear# alkylbenzene# sulfonate# (LAS)),# cationics# (such# as# quaternary# ammonium# derivatives),# amphoterics# (such# as# cocoamidopropyl# hydroxysultaïne# (CAS))# and# nonionics# (such# as# Brij# 35# (B35),# Tween# 80# (TW80)# or#Triton# X# 100# (TX100)).# Non]ionic# surfactants# are# preferably# used# compared# to# ionic# surfactants# due# to# their# lower# soil# sorption# ability,# higher# solubilization# capacity# and# higher#cost]effectiveness#[10]# also# amphiphilic# compounds# able# to# form# micelles.# They# are# of# microbial# origin# and# produced# from# renewable# resources.# Similarly# to# synthetic# surfactants,#biosurfactants#have#high#extraction#capacity#[19,29].#For#example,#Lai#et#al.#

Figure( 1 . 3 .

 13 Figure(1.3.#Structure'of'native'cyclodextrins'(CDs)'and'inclusion'complex'formed'with'

Figure' 1 . 5 .

 15 Figure'1.5.#Partition(equilibria(of(target(pollutant(during(the(heterogeneous(

FentonNlike

  )# hydroxides#precipitation.#This#has#been#partly#solved#by#the#development#of#FentonNlike# processes#(i.e.#the#use#of#solid#ironNcontaining#catalysts#such#as#zeolites,#alumina,#pyrite# or#other#iron#oxides)#[99-102].## The#use#of#other#metallic#ions#as#catalyst#has#also#been#studied.#For#example,#Co,#Cu#and# Mn#could#be#used#to#act#as#catalysts#of#the#Fenton#reaction#[103].# Some# authors# have# also# reported# promising# results# by# coupling# sonochemistry# and# Fenton's#chemistry#for#organoxenobiotic#degradation#[104,105].#Further#combination#of# processes# have# also# been# investigated# such# as# sonoNphotoNFenton# [106]# or# photoN

  The#presence# of# the# surfactant# decreased# gas-liquid# mass# transfer# for# both# NAP# and# ozone.# This# directly#affects#NAP#removal#mechanisms#i.e.#volatilization#and#ozonolysis#(lower#ozone# transfer#from#the#gas#to#the#liquid#phase).#Therefore,#the#use#of#a#rotating#packed#bed#as# ozone# contactor# would# be# more# suitable.# It# allows# increasing# gasRliquid# mass# transfer# coefficients

  the# electrochemically#assisted#Fenton#reaction.#Several#studies#reported#the#degradation#of# a# large# range# of# persistent# organic# pollutants# by# the# EF# process#[46,[147][148][149][150].# This# process#can#also#lead#to#high#TOC#and#COD#removal#from#wastewaters,#indicating#total# mineralization#of#organics#to#CO2#[151].# The#efficiency#of#the#EF#process#can#be#enhanced#by#irradiating#the#EF#reactor#with#an# UV# lamp# (photoREF# process)# or# solar# light# (solar# photoREF# process)# [152,153].# As# explained#above#(see#technologies#based#on#Fenton#reaction#chemistry),#the#interest#is# double:#additional#production#of# • OH#and#ferrous#iron#regeneration#enhancement.# # 3.4.2.#Removal#efficiency#and#kinetics# Electrochemical# processes# have# been# successfully# applied# for# the# treatment# of# SW/SF# solutions# by# using# different# operating# conditions# involving# different# mechanisms# (Figure#1.6).#This#is#why#a#large#range#of#kinetics#has#been#obtained#(0.01#R#2#h R1 )#(Table#

  Figure#1.6.#Schematized+view+of+mechanisms+and+competition+effects,+which+can+occur+

  2.1.#Influence#of#extracting#agents#Concentration# and# nature# of# the# EA# greatly# influence# the# efficiency# of# the# process.# Particularly,# the# high# carbon# content# (EAs,# target# HOCs# and# SOM)# leads# to# high# competition# effects# for# oxidation# with# • OH#(Figure# 1.6).# However,# similarly# to# Fenton# and#photoNFenton#processes,#higher#efficiency#is#usually#obtained#with#the#EF#process#by# using#CDs#as#EA#due#to#the#formation#of#the#ternary#complex#HOCNCDNFe(II)#[56].# A#variety#of#behaviors#and#efficiencies#have#also#been#observed#according#to#the#nature# of# the# surfactant# used,# due# to# different# degradation# pathways# [157].# For# example,# the# COD# removal# of# model# solutions# containing# alkylbenzyldimethylammonium# chlorid# (a# cationic# surfactant)# was# higher# compared# to# the# use# of# SDS.# The# aromatic# structure# of# the# cationic# surfactant# enhanced# the# organic# load# removal# through# the# formation# of# insoluble# species,# while# the# generation# of# oxidationNrefractory# compounds# took# place# with#SDS#(aliphatic#structure)#[157].## Besides,# using# continuous# treatment,# it# has# been# reported# more# than# 80%# of# PAH# degradation# during# the# first# 18# h# of# treatment#by# electroNoxidation# with# DSA# anode# [155].# Thereafter,# removal# efficiency# decreased# owing# to# the# formation# of# a# polymeric# film#on#the#anode#surface#leading#to#its.#This#fouling#phenomenon#has#been#studied#by# investigating#the#influence#of#surfactants#and#anode#materials#during#electroNoxidation# of# phenols# [164].# By# using# graphite# as# anode,# Sripriya# et# al# [164]# observed# that# both# cationic# (cetyltrimethylammonium# bromide)# and# anionic# (SDS)# surfactants# had# an# adverse# effect# on# phenol# removal.# These# surfactants# adsorbed# onto# the# anode# surface,# leading# to# a# blocking# effect.# Using# oxide# coated# titanium# anode,# negative# effects# have# been# observed# with# SDS# and# TW80,# while# positive# effects# have# been# obtained# with# cetyltrimethylammonium# bromide.# In# fact,# this# surfactant# may# have# blocked# the# adsorption# onto# the# electrode# surface# of# cation# radicals# generated# from# phenol# oxidation# and# facilitated# the# chlorine# evolution# reaction# by# increasing# the# surface# concentration#of#chloride#ions#through#formation#of#a#complex#with#chloride#ions#[164].# Recently,#it#has#been#studied#the#influence#of#particle#size#of#micelles#(organic#compound# microNdrop#covered#by#a#layer#of#surfactant)#during#the#treatment#of#real#SW#solutions# containing# atrazine# and# SDS# (anionic# surfactant)# by# AO# using# boron# doped# diamond# (BDD)#anode#[163].#Particularly,#it#has#been#reported#that#the#higher#the#amount#of#SDS# Chapter 1 59# used#during#the#washing#process,#the#lower#the#particle#size#and#the#more#negative#the# superficial# charge# of# particles# [163].# This# is# an# important# parameter# to# take# into# consideration#since#steric#hindrance#of#the#large#micelles#could#prevent#their#oxidation# on#the#anode#surface#[165].#This#is#why#homogeneous#production#of#oxidant#species#in# the#bulk#by#mediated#oxidation#has#to#be#considered#for#the#understanding#of#surfactant# degradation#during#electroNoxidation#of#SW#solutions#[163].#Therefore,#despite#the#steric# hindrance# phenomenon,# it# has# been# observed# a# continuous# decrease# of# the# size# of# particles#during#electrolysis#and#a#complete#mineralization#of#organic#compounds#[165].# # 3.4.2.2.#Influence#of#operating#conditions# ! Electrode)material)The# use# of# active# anode# materials# with# low# oxygen# overpotential# such# as# platinum# or# graphite# led# to# kinetic# degradation# rates# in# the# range# 0.01# N# 0.2# h N1 # (Table# 1.3).# Better# results# have# been# obtained# for# EF# and# AO# processes# using# anodes# with# higher# oxygen# overpotential#(rate#constants#in#the#range#0.5#N#2#h N1 ).#These#latter#EAOPs#have#the#ability# to# produce# significantly# larger# amounts# of# M( • OH),# leading# to# higher# degradation/mineralization#kinetics#[147].# In#a#comparative#study,#better#results#have#been#obtained#by#using#Ti/SnO2#compared#to# Ti/IrO2#as#anode#material#[155].#This#is#explained#by#the#fact#that#Ti/SnO2#has#a#higher# O2#overpotential#(1.9#V#vs#SHE#in#0.05#M#of#H2SO4#for#Ti/SnO2#versus#1.52#V#vs#SHE#in# 0.5#M# of# H2SO4# for# Ti/IrO2#[5]),# leading# to# higher# M( • OH)# accumulation# on# the# anode# surface#[5,155].# The# same# trend# has# been# reported# with# SDS,# which# has# been# more# efficiently# degraded# and# mineralized# on# BDD# anode# than# on# PbO2# anode#[166].# For# similar#reasons,#it#has#also#been#reported#that#a#dimensionally#stable#anode#(DSA)#was# inefficient#for#the#treatment#of#SW#solutions#containing#PHE,#10#g#L N1 #surfactant#and#COD# of# 20,000# mg# O2# L N1 #[157].# In# contrast,# a# BDD# anode# exhibited# much# higher# efficiency#[157].#Recently,#BDD#anodes#have#shown#very#promising#results,#due#to#their#corrosion# stability,# inert# surface# and# high# oxygen# overpotential# (2.3# V# vs# SHE# in# 0.5# M# of# H2SO4)#[5,[START_REF] Haritash | #Biodegradation#aspects#of#polycyclic#aromatic#hydrocarbons#(PAHs):#A# review[END_REF].#However,#their#main#drawback#is#currently#their#high#investment#cost.# Chapter 1 60# Regarding# the# EF# process,# the# choice# of# the# cathode# has# a# significant# influence# on# the# efficiency#of#the#process,#particularly#for#H2O2#accumulation#and#Fe 2+ #regeneration.#Best# results# for# practical# applications# are# usually# obtained# with# gas# diffusion# electrodes# (GDEs)# and# threeNdimensional# electrodes# using# carbonNbased# porous# materials,# in# particular#carbon#felt#cathodes#[168].# Other#mechanisms#than#the#production#of# • OH#on#the#anode#surface#or#in#the#bulk#from# the#Fenton#reaction#can#also#occur#during#electrochemical#processes,#depending#on#the# choice# of# operating# conditions.# Particularly,# oxidation# mechanisms# involved# in# the# electrochemical#treatment#applied#by#the#Sanromán's#group#also#include#direct#electroN oxidation# and# oxidation# mediated# by# oxidants# generated# from# during# the# treatment# from#salts#contained#in#the#wastewater#[159].#However,#lower#degradation#kinetics#have# been#obtained#by#comparison#with#the#EF#process#and#the#AO#process#using#anode#with# higher# oxygen# overpotential# (due# to# the# production# of# larger# amounts# of#

  by#the#choice#of#the#supporting#electrolyte#(K3PO4,#Na2SO4#and#NaCl),#due#to# the# formation# of# oxidant# species# from# the# electrolyte# (mediated# oxidation)#[169].# Furthermore,# it# can# also# affect# the# degradation# pathway# of# organic# compounds:# a# mechanistic#study#on#NAP#and#PYR#electroNoxidation#showed#that#the#oxidation#pathway# included# both# oxidation# by# • OH# produced# on# the# anode# surface# and# chlorine# mediated# electrolysis#[108].# # #of#the#current#density#can#improve#degradation#rates#of#organics#but#also# increases#the#energy#consumption#of#electrochemical#processes.#The#high#COD#content# of# SW/SF# solutions# usually# allows# reaching# high# current# efficiency#[5].# However,# a# too# high# current# density# can# increase# the# portion# of# current# wasted# due# to# the# increase# of# secondary# reactions# (such# as# oxygen# evolution# at# the# anode# and# H2# evolution# at# the# cathode)#[5].# Besides,# degradation# efficiency# of# organic# compounds# can# also# decrease# when#too#high#potentials#are#applied.#For#example,#Tran#et#al.#defined#an#optimal#current# density#of#9.2#mA#cm N2 #for#the#treatment#of#a#mixture#creosote#oil#/#synthetic#surfactant# with# a# Ti/RuO2# anode[156].# The# optimization# of# the# current# density# applied# to# the# electrochemical# cell# is# also# particularly# important# during# the# EF# process.# A# too# high#potential# favors# waste# reactions# and# can# decrease# H2O2# accumulation# in# the# solution#[46].#Finally,#the#balance#between#the#effectiveness#of#electrochemical#processes#and#the# energy#consumption#has#to#be#further#investigated.# # ! pH)A#pH#between#2#and#4#is#usually#required#for#the#EF#process,#while#the#optimal#pH#has# been# defined# as# 3.0#[46].# However,# in# the# area# of# SW/SF# solutions,# the# presence# of# compounds#such#as#SOM#or#CDs#can#allows#keeping#Fe 3+ #in#the#solution#at#near#neutral# pH,# thus# allowing# starting# the# process# at# pH# >4#[56].# Moreover,# the# accumulation# of# carboxylic# acids# during# the# electrochemical# treatment# of# SW/SF# solutions# also# lead# to# decrease#the#pH#around#3#during#the#treatment#[154,157].#Besides,#by#using#a#Ti/RuO2# anode#for#the#electroNoxidation#of#creosote#oil#in#the#presence#of#CAS,#the#initial#pH#did# not# have# any# significant# influence# in# the# range# 2# -# 9# [156].# However,# contradictory# results#have#also#been#reported#on#the#influence#of#the#pH#during#AO#[164].#is#nowadays#one#of#the#most#popular#and#costNeffective#process#in# water#treatment#for#removal#of#organic#compounds#[165].#It#is#based#on#the#metabolism# of#organics#by#a#large#range#of#microorganisms.#Physical,#chemical,#and#microbiological# aspects# of# a# particular# environment# have# to# be# taken# into# consideration# for# understanding# biological# degradation# mechanisms# of# a# given# compound.# Different# microorganisms# and# degradation# pathways# are# involved# depending# on# operating# conditions# in# reactors,# including# composition# of# the# effluent# to# be# treated,# oxygen# concentration,# pH,# temperature,# etc.# [166,167].# Particularly,# biological# processes# are# divided# into# three# main# categories# depending# on# the# final# electron# acceptor:# aerobic,# anaerobic#and#anoxic.#Mainly#aerobic#biodegradation#processes#have#been#applied#to#SW# solutions#due#to#higher#microbial#growth#rates#leading#to#faster#removal#kinetics#[18].# Microorganisms# have# evolved# an# extensive# range# of# enzymes,# pathways,# and# control# mechanisms#that#are#responsible#for#catabolism#of#a#large#range#of#organic#compounds# [168].# Thus,# biological# degradation# is# a# powerful# treatment# used# to# alleviate# a# lot# of# environmental# pollution# issues.# For# example,# several# studies# reported# that# biological# processes#are#able#to#treat#a#variety#of#organic#compounds#such#as#halogenated#organics# [168],#nitroaromatic#compounds#[169],#petroleum#hydrocarbons#[170],#polychlorinated# dibenzodioxins#[171]#or#PCBs#[172].# However,# some# organic# compounds# can# be# recalcitrant# to# biodegradation# for# different# reasons# such# as# the# absence# of# microorganism# able# to# use# them# as# substrate,# the# presence# of# toxic# concentrations# of# a# specific# organic# compound# or# the# decrease# of# bioavailability# of# organic# compounds# due# to# the# physicochemical# parameters# of# the# environment#

Figure$ 1 . 7 .

 17 Figure$1.7.#Organic,pollutant,uptake,by,bacteria,in,soil,washing,solutions.,Km,is,the,micellar,phase,/,aqueous,phase,partition,coefficient,of,the,target,pollutant.,I,is,the,

  of# bacteria# per# mass# of# substrate# consumed);# b# is# the# firstE order# endogenous# respiration# coefficient;# η# is# a# term# linked# to# HOC# solubility# enhancement# by# surfactant;# γ# is# a# term# linked# to# the# bioavailable# fraction# of# micelle# bound#contaminants;#ν#is#a#term#linked#to#the#mass#transfer#between#air#and#gas#phase.# The# model# considers# that# the# enhanced# biodegradation# in# solutions# containing# EAs# is# mainly# attributed# to# an# increased# aqueous# solubility# of# HOCs# (parameter# η# in# Eq.# 8)#[177,178,180,181].#In#contrast,#high#EA#concentrations#exhibit#adverse#effects#due#to#the# inhibition#of#the#direct#contact#between#microbial#cells#and#target#pollutants#by#partition# into#CD#inclusion#complex#or#micelles#(parameter#γ#in#Eq.#8;#parameters#α#in#Table#1.5)#[174,175].#Particularly,#this#approach#introduced#a#bioavailability#parameter#(γ in Eq. 8,α#in#Table#1.5)#assessing#the#bioavailability#of#a#pollutant#in#the#micellar#pseudoEphase.# The#value#1#means#a#total#bioavailability#of#the#target#pollutant#while#the#value#0#means# a# total# nonEbioavailability.# This# parameter# is# strongly# dependant# on# the# nature# and# concentration# of# the# EA,# as# reported# in# Table# 1.5.# This# is# ascribed# to# various# micelle# characteristics# and# HOC# partitioning,# leading# to# a# different# level# of# inhibition# of# the# # microbial# cells# and# target# pollutants.# For# example,# the# low# bioavailability# of# pollutants# in# solutions# containing# Brij ® # 35# was# attributed# to# its# very# long#hydrophilic#chain,#which#may#reduce#the#interaction#and#the#transfer#of#PHE#from# the#micelle#to#the#microbial#cell#[174].# Overall,# the# following# trend# is# usually# observed# for# both# surfactants# and# CDs:# the# presence# of# low# concentration# of# EAs# (below# or# close# to# the# CMC# for# surfactants)# enhances# biodegradation# of# HOCs,# but# the# bioavailability# and# biodegradability# is# reduced# with# increasing# the# EA# concentration# [173]# (Table# 1.5).# Other# potential# mechanisms# of# biodegradation# inhibition# include# toxicity# of# EAs# to# microorganism# [182,183]#and#preferential#microbial#uptake#of#EAs#as#substrate#[183-185].# Finally,# surfactants# can# also# affect# the# oxygen# transfer# coefficient# from# the# gas# to# the# liquid# phase,# which# is# an# important# parameter# in# aerobic# biological# degradation# [186,187].# It# has# been# observed# that# surfactants# influence# the# process# of# bubble# generation.# Particularly,# specific# interfacial# area,# bubble# diameters,# volumetric# mass# transfer#coefficient#and#liquidEside#mass#transfer#coefficient#can#be#modified#[187]

•

  Figure#1.8#depicts#an#explicative#scheme#of#this#mechanism.#

  Eq.#11)# whereby,# C0,# Cm,# Caq# are# the# molar# pollutant# concentration# in# the# total# solution,# in# the# micellar# phase# and# in# the# aqueous# phase,# respectively,# Sm# is# the# molar# surfactant# concentration#in#micelles#and#Ks#is#a#simplified#micellar#partition#coefficient.0In#this#simple#approach,#it#is#assumed#that#Cm#<<#Sm#and#concentration#polarization#is#not# taken#into#consideration,#while#it#has#been#reported#that#this#can#significantly#improve# separation#efficiency#[203].#It#is#also#worth#to#note#that#the#CMC#of#the#surfactant#is#an# #to#consider,#since#it#influences#the#amount#of#surfactant#monomers# passing#through#the#membrane.# Besides,#the#main#drawback#of#membrane#technologies#is#related#to#fouling#issues,#which# lead# to# a# dramatic# increase# of#operating# costs.# Particularly,# natural# organic# matter# is# widely#recognised#to#be#involved#in#the#fouling#of#lowGpressure#membranes#[221,222].# Thus,# SW# solutions# containing# high# load# of# fouling# materials# and# the# increase# of# the# surfactant#concentration#at#the#membrane#surface#can#lead#to#the#formation#of#a#stable# viscous# phase# resistant# to# the# permeate# flow# [223].# This# effect# of# concentration# polarization# depends# on# nature# and# concentration# of# the# surfactant# [203]# and# can# strongly#increase#operating#costs#of#the#process.#However,#a#field#demonstration#showed# that# the# operation# of# MEUF# for# surfactant# reGconcentration# after# an# airGstripping# unit# was#simple#and#trouble#free#[206].# In# contrast# to# most# studies,# Ang# et# al.# [224]# reported# a# selective# removal# of# target# pollutants#by#using#an#ultrafiltration#system:#67%#of#the#surfactant#was#recovered#in#the# permeate,#while#more#than#90%#of#polychlorobiphenyls#and#83%#of#oils#were#retained,# due#to#the#formation#of#oil#droplets#readily#rejected#by#the#membrane.# #

5 . 1 .•# 5 . 2 .Figure

 5152 Figure#1.9#shows#target#pollutant#degradation#kinetics#that#could#be#achieved#as#regards# to#the#degradation#process#used.#Table#1.7#shows#an#overview#of#main#advantages#and# drawbacks#of#each#process#previously#described.#However,#further#studies#about#global# treatment# costs# would# be# necessary,# including# energy# consumption,# reagent# consumption,# transport# of# soil# and/or# effluent,# implementation# and# maintenance# costs# of#the#treatment#plant.#

Figure( 2 . 3 .

 23 Figure(2.1.((Stereomicroscopic-pictures.-A1:-VS-soil-untreated;-A2:-VS-soil-acetone9treated;-A3:-VS-soil-fully-oxidized;-B1:-IdF-soil-untreated;-B2:-20092000-μm-fraction-of-IdF-soil;-B3:-639200-μm-fraction-of-IdF-soil;-B4:-<63-μm-of-IdF-soil;-C:-coal-particle-(from-IdF);-D:-cokeparticle-(from-VS);-E:-glassy-slag-particle-(from-NoF);-F:-solid-aggregates-ofresinified/weathered-tar-oil-and-embedded-soil-particles-(F1:-from-VS,-F2:-from-IdF,-F3:from-Michle).-

  Figure(2.4.-Box-plot-of-the-evolution-towards-heavier-PAHs-of-the-distribution-of-the-16-USEPA-PAHs-in-BPs-of-the-6-soils-analyzed,-compared-to-the-respective-PAH-distribution-in-the-bulk-soils.-Normalized-enrichment-factor-of-PAHs-in-BPs-refers-to-the-ratio-between-the-

  Figure(2.5.-Impact-of-the-presence-of-black-particles-on-PAH-partitioning-behavior-in-aged-tar9oil9contaminated-soils.-A-9-PAH-fraction-according-to-granulometric-fraction-in-Michle,-Sobeslav,-IdF,-NoF-and-Rositz-soils.-PAH-recovery-after-wet-sieving-was-always-above-90%-

  µm;-<63:-<63-µm.-

  Figure(2.6.-PAH-recovery-and-soil-weight-recovery-after-the-two9step-separationprocedure,-according-to-granulometric-fraction-of-IdF-soil.-The-PAH-concentration-in-theupper-black-layer-is-much-higher-than-in-the-lower-layer.-

  Figure(2.7.-Scheme-of-the-course-of-PAH-concentrations-(C)-from-a-tar-oil-phase-over-the-oil9water-interface-into-the-surrounding-water-phase.-Upper-curve:-concentration-profile-ofa-tar-oil-phase-with-homogeneous-viscosity;-lower-dashed-curve:-concentration-profile-fromthe-tar-oil-over-the-resinified-(solidified)-interphase-with-two-mass9transfer-interfaces-(ηoilof-the-tar-oil-phase-is-much-lower-than-ηI-of-the-interfacial-layer);-dotted-line:-externalmass-transfer-from-the-water-phase-into-the-tar-oil-phase-with-solidified-interface.-

  the#following#processes#are#studied# for#the#removal#of#HAs:#AO#using#boron#doped#diamond#(BDD)#anode,#EF#using#Platinum# (Pt)#anode,#and#EF#using#BDD#anode.#Carbon#sponge#(CS)#was#used#as#cathode,#since#it# produces#high#amount#of#H2O2#for#the#EF#process#[44].#Stainless#steel#(SS)#and#CS#were# also# compared# as# cathode# material# for# the# AO# process.# Sorption# of# HAs# onto# the# CS# cathode# was# emphasized# and# the# impact# of# this# phenomenon# on# the# electrocatalytic# # HAs# was# assessed.# Therefore# the# goal# of# this# study# was# (i)# to# show# the# ability# of# EAOPs# for# total# removal# of# HAs# from# water# (ii)# to# assess# and# compare# the# effectiveness# of# various# EAOPs# for# the# removal# of# HAs# from# aqueous# solutions# (iii)# to# understand# HAs# removal# mechanisms# during# EAOPs# (iv)# to# propose# a# new# modeling# approach# to# monitor# TOC# removal# by# taking# into# account# both# sorption# and# oxidation# purchased# from# Acros# Organics.# A# purification# step# was# performed# as# described# below.# Iron# (II)# sulphate# heptahydrated# and# sulphuric# acid# were# of# reagent# grade#obtained#from#Acros#Organics.#Sodium#sulphate#was#of#reagent#grade#purchased# from# Sigma# Aldrich.# Solutions# were# prepared# with# ultrapure# water# from# a# Millipore# MilliMQ#system#(Molsheim,#France)#with#a#resistivity#>18#MΩ#cm.# #2.2.(Preparation(of(solutions(of(HAs(A#purification#step#of#commercial#HAs#was#performed,#similarly#to#the#protocol#of#Arai#et# al.#[45].#The#stock#solution#was#prepared#by#dissolving#1#g#of#commercial#HAs#in#2#L#of# MilliMQ#water#at#pH#3.#This#solution#was#filtered#through#Whatman#GF/F#filter#(0.7#μm#as# pore# diameter).#Then,# HAs# were# precipitated# by# decreasing# the# pH# at# 1.2# and# the# solution# was# centrifuged# at# 3000# rpm# during# 20# min.# The# supernatant# was# then# removed#and#precipitated#HAs#were#dissolved#in#deionized#water#and#stocked#at#pH#3# treatments# were# carried# out# during# 9# h# in# a# 400# mL# batch# electrochemical# cell# containing# 330# mL# of# HAs# solution# at# initial# TOC# concentration# of# 16.2#mg#L M1 #(TOC0).#The#anode#material#was#either#a#plate#of#Pt#(14#cm 2 #x#0.1#cm)#from# Platecxis#(NoisyMleMSec,#France)#or#a#plate#made#of#a#thinMfilm#BDD#onto#a#Nb#substrate# (24# cm 2 # x# 0.2# cm)# purchased# from# Condias# Gmbh# (Itzehoe,# Germany).# The# cathode# material#was#a#CS#(24#cm 2 #×#1.2#cm,#60#pores#per#inch)#from#Magneto#BV#Holland#(The#Netherlands)#or#a#SS#plate#(24#cm 2 #x#0.2#cm)#from#Goodfellow#(France).#Electrodes#were# set# up# with# a# gap# of# 3# cm# between# the# anode# and# the# cathode.# The# constant# current# intensity#was#provided#by#a#power#supply#(HAMEG,#Germany#(model#7042M5)).#Air#was# continuously# bubbled# inside# the# solution# through# a# glass# frit# in# order# to# keep# enough# dissolved# oxygen# in# the# solution# for# the# hydrogen# peroxide# production# at# the# cathode# .# A# magnetic# stirrer# ensured# the# homogenization# of# the# solution# in# the# electrochemical#cell.#Similarly#to#optimal#experimental#conditions#determined#by#Özcan# et# al.# [44],# a# suitable# amount# of# electrolyte# was# dissolved# in# the# solution# (Na2SO4# at# 0.05#M)# and# pH# was# adjusted# at# 3.0# with# 1# M# H2SO4.# For# the# EF# process,# an# optimal# concentration#of#0.1#mM#Fe 2+ #(under#the#form#of#ferrous#sulphate#heptahydrated)#was# added#[44].#According#to#the#electrochemical#cell#configuration,#processes#were#denoted# as#AOMSS#(BDD#anode,#SS#cathode),#AOMCS#(BDD#anode,#CS#cathode),#EFMPt#(Pt#anode,#CS# cathode,#0.1#mM#Fe 2+ )#and#EFMBDD#(BDD#anode,#CS#cathode,#0.1#mM#Fe 2+ ).# # 2.4.(Analytical(procedures( Due# to# the# complexity# of# the# HA# mixture,# organic# matter# content# concentration# was# determined# by# a# global# parameter,# i.e.# the# total# organic# carbon# (TOC)# content# of# the# solution# (TOCsol),# in# mg# L M1 .# Samples# (3.5# mL)# were# collected# at# 8# or# 9# different# time# points#during#the#electrolysis.#TOC#was#measured#by#using#a#Shimadzu#TOCMV#analyzer.# Potassium#hydrogen#phthalate#(99.5%,#Merck)#was#used#for#the#calibration.# For# the# analytic# determination# of# organics# adsorbed# onto# the# CS# cathode# (TOCads),# the# treated# solution# was# removed# from# the# electrochemical# cell.# Then,# 330# mL# of# NaOH# at# 0.1# M# was# used# for# desorption# of# HAs# from# the# cathode,# similarly# to# the# extraction# method# of# HAs# from# soil# [46].# After# 15# min# of# continuous# stirring,# a# sample# was# analyzed#after#inorganic#carbon#removal#from#the#solution#by#decreasing#the#pH#at#3#and# purging# the# sample# with# O2# gas.# Values# were# given# in# mg# L M1 ,# based# on# the# amount# of# carbon# adsorbed# on# the# cathode# compared# to# the# volume# of# the# solution# treated.# Therefore,#the#total#TOC#(TOCtot)#in#the#solution#was#deduced#as#TOCtot#=#TOCsol#+#TOCads.# The# evolution# of# the# UV# spectrum# of# the# solution# and# compounds# adsorbed# onto# the# cathode# was# analyzed# by# using# a# Perkin# Elmer# Lambda# 10# UV/VIS.# Absorbance# values# were#given#in#unit#absorbance#(UA).# Generated# carboxylic# acids# were# monitored# by# ionMexclusion# HPLC,# as# detailed# by# OlveraMVargas#et#al.#[47].# Chapter 3

  HAads]#and#HA#concentration#in#the#bulk#([HAsol]),#and#kads#is# the#fitting#parameter#for#the#model#(h M1 ).# Therefore,#the#following#Eq.#10#is#the#general#equation#for#the#sorption#process#of#HAs# onto#the#CS#cathode#during#the#electrolysis,#d[HA !"# ] dt = ! !"# [HA] !"! ( HA !"# !" -[HA !"# ]) ! # #(Eq.#10)# Additional# assumptions# took# into# consideration# for# the# model# are# discussed# in# the# 'results#and#discussion'#part,#according#to#the#experimental#results#observed.# Calibration# of# the# model# was# performed# by# adjusting# unknown# parameters# until# the# model#outputs#adequately#fit#the#experimental#observations.#Three#methods#were#used# for# the# comparison# of# model# results# with# experimental# measurements,# the# Root# Mean# Square# Error# (RMSE)# (Eq.# 11),# the# Modeling# Efficiency# (ME)# (Eq.# 12)# and# the# Index# of#

Figure( 3 . 2 .

 32 Figure(3.1.#Evolution#of#TOCsol#during#the#electrolysis#of#HAs#(TOC0#=#16.2#mg#L N1 )#in# 0.05#M#Na2SO4#solution#by#the#AONSS#process#according#to#the#current#intensity#applied# (300#-#600#-#1000#mA).#Error#bars#refer#to#triplicate#experiments.#Lines#report#model# results.#

Figure# 3 Figure( 3 . 5 .

 335 Figure# 3.4.# A# fast# decrease# of# TOCsol# was# observed# during# the# first# 40# min# of# the# treatment.# Simultaneously,# more# than# 85%# of# the# initial# TOC# adsorbed# onto# the# CS# cathode.#The#enhancement#of#the#adsorption#process#could#be#ascribed#to#the#formation# of# a# complex# between# HAs# and# iron# ions,# leading# to# charge# neutralization# of# HAs.# This# was# confirmed# by# iron# analysis# during# the# EFMPt# process.# After# 15# min# of# treatment,# 45%#of#the#iron#in#the#solution#was#in#the#fraction#>0.7#μm.#This#indicates#the#formation# of# macro# complex# between# iron# and# HAs.# Then,# this# ratio# continuously# decreased# and# reached#26%#after#7#h#of#treatment.#This#can#be#attributed#to#the#lower#affinity#between# HABPs#and#iron#ions,#leading#to#a#lower#formation#of#complex.#

Figure( 3 . 6 .

 36 Figure(3.6.#Evolution#of#TOCsol#and#TOCads#during#the#electrolysis#of#HAs#solution#(TOC0#=# 16.2#mg#L N1 )#by#EFNBDD#process#at#300#mA#(0.05#M#Na2SO4;#0.1#mM#Fe 2+ ).#Symbols#report# experimental#results.#Error#bars#refer#to#triplicate#experiments.#Lines#report#model#results.#

#

  As#regards#to#the#sorption#process,#the#predetermined#value#of#[HA]ads_eq#for#the#AOMCS# process# allowed# a# good# fitting# with# the# evolution# of# TOCads.# The# proposed# sorption# model#also#fitted#well#with#the#low#TOCsol#and#high#TOCads#concentration#reached#after# 40# min# of# treatment# during# the# EFMPt# and# EFMBDD# processes.# However,# high# RMSE# as# well#as#low#ME#and#IoA#values#were#calculated#for#the#evolution#of#TOCsol#during#EFMPt# and#EFMBDD#processes.#This#is#due#to#the#overestimation#of#the#kinetic#of#TOCsol#decrease# during# the# first# 40# min# of# the# treatment.# Without# taking# into# account# experimental# points#at#t#=#0.17#h#and#t#=#0.33#h,#ME#values#are#greatly#improved#for#EFMPt#and#EFMBDD# (0.994#and#0.997,#respectively).#Interestingly,#the#use#of#a#lower#kads#parameter#did#not# improve#the#global#model#quality.#It#led#to#an#underestimation#of#the#adsorption#rate#of# HAs,# since# a# greater# amount# of# HAs# is# degraded# (formation# of# HABPs)# before# to# be# adsorbed.# Therefore,# the# experimental# results# could# only# be# explained# by# considering# additional# mass# transfer# limitations.# Particularly,# this# could# be# related# to# a# diffusion/convection#mechanism#corresponding#to#the#time#necessary#for#the#solution#to# fully# penetrate# into# the# porous# CS# cathode.# In# fact,# the# real# CS# surface# available# for# adsorption#of#HAs#and#H2O2#production#is#progressively#increasing#during#the#beginning# of#the#process.#Further#investigations#and#experimental#results#would#be#necessary#for# the#calibration#of#this#process.# # were# developed# for# EAOPs# in# order# to# monitor# the# degradation# of# single# model# organic# compounds# such# as# phenol# [39]# by# following# the# generation# of# oxidation# byMproducts# until# total# mineralization.# However,# in# a# complex# mixture# of# organic# compounds# such# as# HAs,# alternative# model# based# on# global# parameters# (TOC,# chemical# oxygen# demand)# are# required.# Moreover,# it# is# the# first# time# that# sorption# processes#are#taken#into#consideration#for#the#modelling#of#TOC#removal#during#EAOPs.# The#next#step#would#be#to#combine#this#model#with#previous#research#works#modeling# the#generation#and#the#role#of# ! OH#according#to#operating#conditions#[25,59-61].# #reported#for#the#first#time#the#removal#of#HAs#by#various#EAOPs.#Here#are#the# following#main#results#and#conclusions#drawn#from#results#obtained:# • More#than#99%#of#TOC#of#initial#solution#(16.2#mg#L M1 )#was#removed#after#7#h#of# treatment# at# 1000# mA# using# AO# process# with# BDD# anode# and# SS# cathode.# This# process#generates#low#amount#of#intermediates#and#led#to#rapid#mineralization#of# HAs#to#CO2.# • The# use# of# CS# material# as# cathode# led# to# significant# adsorption# of# HAs# onto# its# surface.#This#resulted#in#a#lower#amount#of#HAs#oxidized#during#the#AO#process.# Addition# of# iron# during# the# EF# process# strongly# enhanced# both# kinetic# and# capacity#of#HA#adsorption#onto#the#CS#cathode.# • Hydroxyl# radicals# produced# from# the# Fenton's# reaction# oxidized# organic# compounds#adsorbed#onto#the#cathode,#as#they#are#produced#in#a#homogeneous# way#in#the#bulk.#This#resulted#in#the#release#of#hydrophilic#HABPs#in#the#solution.## • The# mineralization# to# CO2# of# HABPs# was# much# more# efficient# by# using# the# BDD# anode,# compared# to# the# Pt# anode,# due# to# its# higher# catalytic# activity# for# heterogeneous# ! OH#production.# • The#proposed#model#allowed#monitoring#TOCsol#and#TOCads#evolution#during#AOM SS,# AOMCS,# EFMPt# and# EFMBDD# process.# It# took# into# account# both# sorption# and# oxidation# processes# as# well# as# two# different# types# of# organics# (low# or# nonM degraded# HAs# and# hydrophilic# HABPs).# However,# the# reliability# of# this# model# should#be#validated#with#different#experimental#conditions,#such#as#various#initial# concentrations,# nature# of# organics,# current# intensity.# Moreover,# it# was# emphasized# that# diffusion/convection# of# the# solution# inside# the# CS# cathode# should# be# also# considered# for# the# assessment# of# the# catalytic# activity# of# this# material#for#H2O2#generation#as#well#as#for#sorption#processes.# To#conclude,#EAOPs#are#promising#processes#for#the#production#of#high#quality#organicM free# water,# particularly# when# BDD# anode# is# used.# As# regards# to# drinking# water# #issues,#it#would#be#interesting#to#evaluate#the#evolution#of#the#potential# of# formation# of# disinfection# byMproducts# in# parallel# with# energy# consumption# optimization.

  Figure(4.3.(Effect(of(initial(Tween® (80(concentration(on(the(apparent((pseudo3first(order)( degradation(kinetics((kapp)(of(phenanthrene(([PHE]0(=(0.1(μM)(and(Tween ® (80((TW80)(in(a(

  Figure(4.4.(Determination(of(the(absolute((second3order)(rate(constant(for(oxidation(of( Tween ® (80(by(BDD( • OH)(at(C<CMC(condition((C(=(7.5(μM)(by(competition(kinetics(method(

  Figure(4.5.(Treatment(of(a(binary(mixture((HBA(/(TW80((a(and(b)(or(PHE(/(TW80((c))(by( AO(([Na2SO4](=(0.05(M;(V0(=(330(mL).((a):(ratio(R(between(the(apparent((pseudo3first(

  Figure(4.7.%Influence(of(the(supporting(electrolyte((either(0.05(M(Na2SO4(or(0.1(M(NaClO4)( on(the(degradation(of(Tween ® (80(([TW80]0(=(1(M)(during(treatment(by(AO(at(200(mA(and(

  Figure(4.8.%Time(course(of(phenanthrene(([PHE]0(=(0.14(mM)(and(Tween ® (80(([TW80]0(=(

  Figure(4.9.%PAHs((PHE,(ANT,(FLUO,(PYR)(extraction(efficacy(from(a(historically(

(Figure( 5 . 4 .

 54 Figure$ 5.1.$ At$ increasing$ current$ intensity,$ the$ degradation$ of$ organic$ compounds$ was$ faster.$ More$ than$ 95%$ removal$ of$ PHE$ was$ observed$ after$ 5$ h$ of$ treatment$ at$ 1$ A$ constant$ current$ electrolysis.$ However,$ faster$ degradation$ kinetics$ had$ already$ been$ reported$by$using$AO$with$a$similar$setup.$Complete$degradation$of$0.1$mM$atrazine$in$ pure$aqueous$solution$had$been$observed$in$20$min$of$treatment$by$AO$at$500$mA$[24],$ while$the$absolute$degradation$rate$of$atrazine$by$hydroxyl$radicals$was$5$times$lower$ than$that$obtained$for$PHE$[START_REF] Sanly | #A#study#on#the#removal#of#humic#acid#using# advanced# oxidation# processes[END_REF]59].$In$this$study,$a$slower$degradation$rate$was$mainly$ attributed$to$the$presence$of$high$amount$of$additional$organic$compounds$(TW80,$HAs)$ acting$ as$ hydroxyl$ radical$ scavengers$[60].$ The$ partition$ of$ PHE$ inside$ TW80$ micelles$ may$also$reduce$the$availability$of$PHE$towards$hydroxyl$radicals$[33,61].$$

• 5 232

 5 Figure(5.5$(a)#TimeQcourse#of#the#concentration#of#the#main#shortQchain#carboxylic#acids# produced#during#the#AO#of#the#SW#solution#(I#=#500#mA;#[Na2SO4]#=#0.05#M;#VT#=#330#mL);# (b)#TimeQcourse#of#the#sum#of#the#shortQchain#carboxylic#acids#detected#during#the#AO#of# the#SW#solution,#in#dependence#on#the#current#intensity.#

•

  Practicum -Industrial regulation (52 h) -University of Paris-Est (France).• Lecture courses -Industrial regulation (12 h) -University of Paris-Est (France).

3.'Removal'of'hydrophobic'organic'compounds'from'soil'washing/flushing' solutions'by'degradation'processes

		'	'	'	'	'	'	'	33'
	3.1.!Heterogeneous!photocatalysis!!!	!	!	!	!	!	34!
	3.1.1.!General!considerations!! !	!	!	!	!	!	34!
	3.1.2.!Removal!efficiency!and!kinetics!! !	!	!	!	!	35!
	3.1.2.1.!Influence!of!extracting!agents!!	!	!	!	!	39!
	3.1.2.1.!Influence!of!operating!conditions! !	!	!	!	42!
	3.2.!Technologies!based!on!Fenton!reaction!chemistry! !	!	!	43!
	3.2.1.!General!considerations!! !	!	!	!	!	!	43!
	3.2.2.!Removal!efficiency!and!kinetics!! !	!	!	!	!	44!
	3.2.2.1!Influence!of!extracting!agents!!	!	!	!	!	48!
	3.2.2.2!Influence!of!operating!conditions! !	!	!	!	49!
	3.3.!Ozone!processes!!	!	!	!	!	!	!	!	51!
	3.3.1.!General!considerations!! !	!	!	!	!	!	51!
	3.3.2.!Removal!efficiency!	!	!	!	!	!	!	52!
	3.4.!Electrochemical!processes!!	!	!	!	!	!	!	53!
	3.4.1.!General!considerations!! !	!	!	!	!	!	53!
	3.4.2.!Removal!efficiency!and!kinetics!! !	!	!	!	!	54!
	3.4.2.1.!Influence!of!extracting!agents!!	!	!	!	!	58!
	3.4.2.2.!Influence!of!operating!conditions! !	!	!	!	59!
	3.5.!Biological!treatments!! !	!	!	!	!	!	!	62!
	3.5.1.!General!considerations!! !	!	!	!	!	!	62!
	3.5.2.!Removal!efficiency!!	!	!	!	!	!	!	62!
	3.5.3.!Influence!of!extracting!agents! !	!	!	!	!	65!
	3.6.!Combination!of!advanced!oxidation!processes!and!biological!processes! 69!
	3.7.!Selective!degradation!of!target!pollutants! !	!	!	!	70!
	4

.'Selective'separation'of'target'pollutants'from'soil'washing/flushing''''''''

												'
	solutions'	'	'	'	'	'	'	'	'	'	'	75'
	4.1.!GasFliquid!extraction!! !	!	!	!	!	!	!	75!
	4.2.!LiquidFliquid!extraction!!	!	!	!	!	!	!	76!
	4.3.!Membrane!processes!! !	!	!	!	!	!	!	78!
	4.4.!Adsorption!processes!! !	!	!	!	!	!	!	79!
	5.'Conclusions'and'recommendations' '	'	'	'	'	'	83'
	5.1.!Decontamination!of!soil!washing/flushing!solutions!by!degradation!
	processes!! !	!	!	!	!	!	!	!	!	83!
	5.2.!Recovery!of!extracting!agents!and!soil!washing!solution!reuse!	!	86!
	References

Table !

 !

			Introduction
	1."Area%of%identified%contaminated%sites%and%estimated%maximum%area%of%current%
	potentially%contaminating%industry%(‰%of%the%total%country%area)%in%the%different%member%
		states%of%European%Union.%Data%from%[2].%
		Total country area (km 2 )	Area (‰) of identified contaminated sites Min Max	Estimated max area (‰) of current potentially contaminating industry
	Austria	83858	0.2
	Belgium	30528	4.2
	Bulgaria	110879	7.0
	Cyprus	9250	-		-
	Czech Rep	78870	1.1	12
	Denmark	43100	6.5	69
	Estonia	45227	0.1	1.4
	Finland	338144	0.1	1.2
	France	675417	0.1	1.4
	Germany	357022	0.8	8.4
	Greece	131960	-
	Hungary	93028	0.2	1.7
	Ireland	70273	0.0	0.5
	Italy	301263	8.3
	Latvia	64189	0.1	0.8
	Lithuania	65300	7.2
	Luxembourg	2600	7.7	81
	Malta	316	<0.1	6.3	-
	Netherlands	41543	5.3	56	120
	Poland	312685	35
	Portugal	92200	-
	Romania	238291	15
	Slovakia	49033	0.1	0.9
					5"

Table ! 2."Some%physicochemical%properties%of%the%16%USEPA%PAHs.%Data%from%[15-17].%

 !

					Water		Henry
	PAHs	Formula	MW (g mol -1 )	Density	Solubility at 25°C	Log Koc	constant at 25°C
					(mg L -1 )		(Pa m 3 mol -1 )
	Naphthalene	C 10 H 8	128.2	1.162	32	3.2	49
	Acenaphthylene	C 12 H 8	152.2	1.194	3.9	3.4	-
	Acenaphthene	C 12 H 10	154.2	1.024	3.4	3.7	15
	Fluorene	C 13 H 10	166.2	1.203	1.9	3.9	9.2
	Phenanthrene	C 14 H 10	178.2	1.172	1.3	4.2	4.0
	Anthracene	C 14 H 10	178.2	1.240	7.0×10 -2	4.2	5.0
	Fluoranthene	C 16 H 10	202.3	1.236	2.6×10 -1	4.6	1.5
	Pyrene	C 16 H 10	202.3	1.271	1.4×10 -1	4.6	1.1×10 -3
	Benzo[a]anthracene	C 18 H 12	228.3	1.174	1.0×10 -2	5.3	2.0×10 -2
	Chrysene	C 18 H 12	228.3	1.274	2.0×10 -3	5.3	1.0×10 -2
	Benzo[b]fluoranthene	C 20 H 12	252.3	-	1.5×10 -3	5.7	5.0×10 -2
	Benzo[k]fluoranthene	C 20 H 12	252.3	-	8.0×10 -3	5.7	6.9×10 -2
	Benzo[a]pyrene	C 20 H 12	252.3	1.284	3.8×10 -3	6.7	5.0×10 -2
	Indeno[1,2,3-cd]pyrene C 22 H 12	276.3	-	2.0×10 -4	6.2	2.9×10 -2
	Dibenzo[a,h]anthracene C 22 H 14	278.3	1.252	5.0×10 -4	6.5	4.8×10 -3

Introduction

7"

3.4.(Organic(cosolvents(and(vegetable(oil(

			Chapter 1
	expensive# among# the# native# ones# [21].# However,# its# low# solubility# increases# its# soil#
	sorption# and# limits# its# application# for# SW/SF# experiments.# Consequently,# derivative#######
	β]CDs# have# been# marketed# and# proved# their# high# water]solubility# and# efficiency.#
	Moreover,#derivative#CDs#exhibit#better#extracting#capacity#than#the#native#ones#[21].#
	The# analysis# of# the# enhancement# of# HOCs# solubility# by# using# different# surfactants# and#
	CDs# revealed# that# CDs# have# a# lower# ability# to# solubilize# HOCs# than# traditional#
	surfactants#[36].#They#are#usually#ten#times#less#efficient,#depending#on#the#nature#of#the#
	CD#and#surfactant#used#[21].#
	#	1.37!nm!	1.53!nm!	1.69!nm!
		0.57!nm!	0.78!nm!	0.95!nm!
	0.78!nm! 2.The#use#of#organic#co]solvents#(esters,#ketones,#alcohols,#alkylamines#and#aromatics#for#
	example)# is# no# longer# considered# to# be# a# promising# technique.# It# implies# several#
	αACD! important#drawbacks,#such#as#high#costs,#risks#of#handling#and#storing,#toxicity#and#soil# βACD! γACD!
	permeability# disturbing# [29].# Moreover,# their# effect# is# usually# not# significant# until# the#
	volume]fraction#concentration#used#is#above#10%#[21].#
	Hydrophilic!part! However,#it#has#been#shown#that#vegetable#oil#could#favorably#replace#costly,#toxic#and# HOC$
	Hydrophobic!part! low]biodegradable#organic#solvents#for#HOCs#removal#from#soil#[29].#For#instance,#more#
	than#90%#of#the#total#PAHs#from#a#heavily#contaminated#soil#has#been#removed#by#using#
	a# sunflower# oil]soil# ratio# of# 2:1# (v/w)# [37].# It# is# worth# to# mention# that# further#
	assessment# of# costs,# ecological# risks,# and# treatment/disposal# of# contaminated# oil# is#
	necessary# because# of# huge# quantities# of# vegetable# oil# needed# [38].# Moreover,# the#
	production#of#the#vegetable#oil#also#involves#large#areas#of#cultivated#fields#as#well#as#the#
	use#of#high#amounts#of#pesticides#increasing#environmental#risks.##
	#
	2.3
				31#

.5.(Other(alternative(extracting(agents(

	Chapter 1 Chapter 1
	surfactant# foams# leading# to# homogeneous# displacement# fronts# [23]# and# gemini# 3
	surfactants# for# their# low# CMC# [11].# However,# further# studies# are# necessary# to# assess#
	their# efficiency# in# different# remediation# cases.# Moreover,# the# production# at# industrial#
	scale# of# some# of# them# is# still# the# main# issue# for# their# extensive# application# in# soil#
	remediation#[11].#
	Some#other#alternative#EAs#have#also#been#reported,#including#salmon#deoxyribonucleic#
	acid# [16]# and# humic# acids# [39]# for# their# amphiphilic# properties,# soil# nano]particles#
	(composed# mainly# by# organic# carbon# and# inorganic# clay# material)# due# to# their#
	adsorption# capacities# [40],# polymers# for# their# ability# to# change# water# viscosity# [23],#
	32#	33#

.( Removal( of( hydrophobic( organic( compounds( from( soil( washing/flushing(solutions(by(degradation(processes(

	Electrochemical# advanced# oxidation# processes# (EAOPs),# heterogeneous# photocatalysis#
	and# technologies# based# on# Fenton# reaction# chemistry# (including# homogeneous#
	photocatalysis# such# as# photo]Fenton)# have# been# largely# applied# to# the# treatment# of#
	SW/SF#solutions#[41-43].#These#AOPs#are#based#on#the#generation#of#strong#oxidants,#in#
	particular,#hydroxyl#radicals#( • OH).#The#main#characteristics#of#this#radical#are#[44-46]:#
	• a#very#strong#oxidizing#power:#E °(• OH#/H2O)#=#2.8#V/SHE;#
	• a#non]selective#feature#towards#organic#compounds;#
	• a#very#short#average#lifetime#of#few#nanoseconds#in#water.#

.(Heterogeneous(photocatalysis( 3.1.1.(General(considerations(

	Chapter 1 Chapter 1
	Removal#of#HOCs#from#SW/SF#is#investigated#either#in#synthetic#SW/SF#solutions#[56]#or# degradation# of# organic# contaminants# by# heterogeneous# photocatalysis# [58,61,63].# This#
	in# real# SW/SF# solutions# [17].# With# synthetic# solutions,# chemical# substances/pollutants# process#is#schematically#described#in#Figure#1.4.##
	initially# present# in# the# solution# are# totally# controlled:# concentration# of# pollutants,#
	surfactants/cosolvents,# or# other# initial# parameters# such# as# the# presence# of# dissolved#
	organic#matter.#The#use#of#simple#systems#like#synthetic#solutions#makes#the#control#of#
	selected#parameters#easier#and#leads#to#a#better#understanding#of#mechanisms#involved#
	during# the# treatment.# However,# it# does# not# reproduce# real# parameters# affecting# the#
	process#efficiency.#A#lot#of#synergetic,#competing#or#scavenging#effects#can#occur#in#real#
	SW/SF# solutions,# depending# on# the# presence# of# different# nature# and# concentration# of#
	pollutants,#SOM,#or#metallic#ions,#for#example.#This#is#the#reason#why#the#efficiency#of#a#
	process#for#SW/SF#solution#treatment#has#to#be#assessed#by#using#real#SW/SF#solutions.#
	Therefore,#both#kinds#of#studies#are#complementary.#
	#
	3.1Photolysis# of# organic# compounds# is# an# important# mechanism# in# natural# environment#
	(solar#photolysis)#but#this#process#is#not#effective#enough#for#industrial#applications#on#
	highly#contaminated#wastewaters.#However,#coupling#light#irradiation#with#the#addition#
	of#a#photocatalyst#increases#the#efficiency#due#to#the#formation#of# • OH.#Several#authors#
	have# reviewed# the# application# of# this# photocatalytic# process# for# the# treatment# of#
	hazardous#organic#compounds#in#wastewaters#[57-62].#The#process#is#based#on#the#use#
	of#semiconductors#exhibiting#a#band#gap#region#in#which#no#energy#levels#are#available#
	to# promote# the# recombination# of# an# electron# and# hole# produced# by# photoactivation# in#
	the# solid# semiconductor# (Eq.# 2).# This# band# gap# (Eg)# extends# from# the# top# of# the# filled#
	valence#band#to#the#bottom#of#the#vacant#conduction#band.#
	• target# pollutants# removal:# influence# of# operating# conditions# and# specific# SW/SF# ℎ! + !"#$%&'()%*&+! → ℎ ! + ! ! # (Eq.#2)#
	solution# characteristics# (particularly# high# EA# concentrations)# on# degradation#
	kinetics;# By# far,# titanium# dioxide# (TiO2)# is# the# most# largely# used# compared# to# other#
	• operating# cost# optimization# (reagent# consumption,# treatment# time,# energy# semiconductor#photocatalysts#due#to#its#cost]effectiveness,#inert#nature#(i.e.#stable#under#
	consumption,#sludge#production#etc.);# different# reaction# conditions)# and# photostability# (i.e.# able# to# promote# reactions#
	• recovery#of#EAs#and#reuse#of#SW/SF#solutions.# efficiently# upon# repetitive# use).# Several# authors# have# reviewed# and# described# the#
	34#	35#

# #

Figure(1.4.#Schematic'representation'of'the'oxidation'mechanism'of'organic'compounds'

	(R)'by'the'photocatalytic'process.'Adapted'from'the'reference'[63].'

3.1.2.(Removal(efficiency(and(kinetics(

		Chapter 1	Chapter 1
	Since# • OH#have#a#non]selective#reactivity#towards#organic#compounds,#the#SOM#acts#as#a# Table&1.1
	strong# • OH#scavenger#[67-69].#
	Most# of# the# studies# only# investigated# the# first# step# of# target# pollutant# degradation.#
	O 2(ads) Further# studies# about# total# organic# carbon# (TOC)# and# chemical# oxygen# demand# (COD)# hν
	removal# as# well# as# toxicity# evolution# would# be# necessary# since# these# measurements# TiO 2 Reduction provide# reliable# and# significant# results# concerning# the# efficiency# of# the# treatment# and#
	Conducting band quality#of#the#effluent.#		O 2 !-, H 2 O 2
	#	e -	! OH	R
	Band gap	Recombination
		h +
	Valence band		OH -, H 2 O
		Oxidation
	hν	! OH
			37#
	Complete# degradation# of# target# pollutants# has# been# achieved# with# degradation# rate#
	constants# in# the# range# of# 0.1# ]# 10# h ]1 # and# by# using# several# kinds# of# pollutants# and#EAs#
	(Table#1.1).#
	A# decrease# in# degradation# rates# is# observed# with# real# SW/SF# solutions.# Thus,# the#
	process#needs#to#last#longer#in#order#to#reach#similar#effectiveness#than#with#synthetic#
	SW/SF#solutions#[64-66].#This#is#ascribed#to#adverse#effects#from#the#presence#of#SOM.#
	36#

.#SW/SF%solution%treatment%by%photocatalytic%processes.# Pollutant (concentration) Extracting agent (concentration) Synthetic (S) / Real (R) solution Volume Operating conditions Degradation rate constant Observations Reference

	Chapter 1 Chapter 1	Chapter 1
	Semiconductor (concentration) TiO 2 (0.4 g L -1 ) TiO 2 (1.7 g L -1 ) The# use# of# low# surfactant# concentrations# (below# or# close# to# the# CMC)# improves# the# Irradiation light (°C) NAP 1 (0.03 mM) B35 (1.2 mM) S 5 mL W) with 340 filter 5 mL 0.78 h -1 PCP 2 (0.2 mM) -CD, MCD, HPCD (0-5 mM) S 35 mL UV lamp (125 W) 7; 11 19 0.3-5.3 h -1 cm -2 ) PCP 2 (0.018 mM) TX100 (0.023-1.01 mM) S 500 mL (39.0-27.5 mW 1.8-9.3 h -1 Solar light ! Surfactant:*influence*of*nature*and*dose* TiO 2 (0.4 g L -1 ) filter 5.7 -La-B codoped nm cut-off R lamp with 400 0.1-3.3 h -1 nm cut-off 3 -(400 W): Xe characteristics#of#the#photocatalyst.## Visible light Xe lamp (1500 2.04 h -1 PHE 4 (0.16 mM) and PYR 5 (0.05 mM) MCD (83 mM) S W) depends# on# pollutant# and# surfactant# properties# and# concentration# as# well# as# surface# -TiO 2 (1 g L -1 ) nm) lamp (150 6 22 -oxidant#species#such#as# • OH#formed#at#the#surface#of#the#catalyst#(Figure#1.4).#Adsorption# UV (200-280 pH T SWEP 3 residues (17 mg L -1 ) C 12 E 8 ; SDS; hexadecyltrimethylammo-nium bromide (8.6 mM) S; R 500 mL TiO 2 (0.2-1.0 g L -1 ) Hg lamp (125 3.0; 3.1.2.1.#Influence#of#extracting#agents# Lower# effectiveness# for# degradation# of# HOCs# by# photocatalysis# has# been# obtained# by# W) with 300 nm cut-off filter 5.6; 8.0 25 -increasing# surfactant# concentration# higher# than# the# CMC# (such# as# in# SW/SF# solutions)# The#efficiency#of#the#process#tightly#relies#on#the#adsorption#capacity#of#target#pollutants# onto# the# photocatalyst# [75]# because# it# promotes# the# oxidation# of# organics# by# highly# [75].# This# is# due# to# the# competitive# partition# of# target# pollutants# in# the# micelle# that#	real SW/SF solution with the same B35 concentration. The higher CD concentration, the lower PCP degradation rate Photocatalytic degradation kinetics are directly linked to adsorption properties particularly above the CMC. the lower PCP degradation rate, The higher the TX100 concentration, degradation rate constant is 4 times lower with B35 and 10 times lower in Compared to solutions without B35, Very slow degradation rate The presence of surfactants largely affects degradation kinetics. Important influence of the nature of the surfactant. Bubbling air improved treatment performances.	[71] [75] [70] [74] [65]
	NAP 1 (0.2 mM) PCB (53 mg L -1 ) alkylphenols removal#of#HOCs.#This#beneficial#effect#has#been#explained#by#the#following#mechanism# TX100 (0.04-0.13 mM) S 1 L TiO 2 (0.1 g L -1 ) Solar light simulator (50 µW cm -2 ) 7 30 1.9-4.2 h -1 soya lecithin and TX100 R 1 L TiO 2 (0.5 g L -1 ) Fluorescent lamp (330-400 nm) (8 W) -20 -S 5 mL TiO 2 (0.1 g L -1 ) Xe lamp (1500 0.1-4.9 h -1 [75].#First,#nonNionic#surfactant#monomers#quickly#combine#with#the#modified#surface#of# B35 (1 and 10 mM); C 12 E 8 (1 and 10 mM); SDS (15 W) with 340 nm cut-off -55 the# catalyst.# This# comes# from# the# interaction# with# hydrophobic# sites# on# the# catalyst# mM); mixtures filter R 5 mL TiO 2 (0.2 and 0.05-1.86 h -1 surface.#Thus,#a#superficial#reactive#monolayer#is#formed#on#the#catalyst#surface.#Finally,# 0.5 g L -1 ) the#target#pollutant#implants#into#the#hydrophobic#space#among#the#surfactant#head#and#	The higher TX100 concentration, the lower NAP 1 degradation rate and TX100 recovery Low degradation rate (treatment time = 15 days). Better results for PCB Important influence of the nature of the surfactant degradation rate with soya lecithin as extracting agent.	[72] [73] [76]
	Aromatic compounds PHE 4 (0.006 mM) the# catalyst# surface# system.# This# promotes# its# availability# to# photogenerated# oxidant# B35 (25 mM) S 5 mL TiO 2 (0.5 g L -1 ) Xe lamp (1500 W) with 340 nm cut-off filter -55 0.12-3.48 h -1 (for individual pollutants) TX100 (1.6-4.8 mM) S -TiO2 (0.1-0.5 g L -1 ) Monochromatic (254 nm) UV lamp (8 W) 3.6; 8.1 25 1.4-3.5 M -1 min -1 species#[75].#	Addition of peroxydisulfates has improved treatment performances Effect of O 2 , H 2 O 2 and radical scavengers has also been studied	[66] [77]
	Cationic# surfactants# also# greatly# enhance# the# adsorption# of# target# pollutants# at# low#
	surfactant# concentration# [78,79].# The# superficial# reactive# monolayer# formation# at# the#
	surface# of# the# catalyst# is# ascribed# to# electrostatic# interactions.# Besides,# higher#
	effectiveness# for# photocatalytic# degradation# has# been# obtained# in# solutions# containing#
	38# mixed# cationic-nonionic# surfactants# compared# to# solutions# with# single# surfactants,#
	indicating#synergistic#effects#in#complex#systems#[78].#
	However,# it# is# important# to# mention# that# the# effect# of# surfactants# on# more# hydrophilic#
	compounds#(such#as#oxidation#byNproducts)#is#less#favorable,#even#at#low#concentration#
	[79].# This# may# be# attributed# to# the# lower# fraction# of# organic# compounds# implanted# in#
	the#superficial#hydrophobic#reactive#monolayer#(lower#Km)#and/or#to#a#different#locus#of#
	implementation# of# these# organic# compounds# inside# this# monolayer# (closer# to# the#
	hydrophilic#heads#of#surfactants),#which#decrease#their#availability#for#oxidant#species.##
	#
	40#	39#

Surfactant monomer Pollutant Micelle Reactive superficial monolayer TiO 2

	Chapter 1 Chapter 1 Chapter 1
	following# order# of# effectiveness# for# bentazone# degradation# was# obtained# [64]:# B35# 3.1.2.2.#Influence#of#operating#conditions# ! pH*
	(C12E23)#>#poly(oxyethylene)#dodecyl#ether#(C12E8)#>#C12E5.#The#lower#inhibitory#effect#of# ! Nature*and*dose*of*the*photocatalyst* The# pH# can# also# influence# oxidation# mechanisms# and# surface# properties# of#
	B35#has#been#explained#by#the#bigger#dimension#of#its#hydrated#polar#head.#It#reduces#
	the# surfactant# adsorption# on# TiO2# surface# and,# therefore,# the# competition# between# The# nature# of# the# photocatalyst# has# a# great# influence# on# the# efficiency# of# the# process# photocatalysts,# leading# to# adverse# effects# such# as# aggregation# of# semiconductor#
	bentazone#and#B35#for#occupation#of#active#sites#on#the#catalyst#surface.# particles,#repulsion#force#between#organic#compounds#and#the#photocatalyst#surface#or# [61].# For# example,# Liu# et# al.# [75]# showed# that# La-B# coNdoped# TiO 2# has# better# performances#than#the#commercial#P25#TiO2#for#the#treatment#of#SW/SF#solutions,#due# lower#production#of# " OH#from#hydroxide#ions#reaction#with#holes# [61,77] .#Therefore,#the#
	# to#higher#adsorption#of#pollutants#on#the#catalyst#surface#and#stronger#absorption#in#the# pKa#of#target#pollutants#and#the#isoelectric#point#of#photocatalysts#have#to#be#taken#into#
	! CDs:*influence*of*nature*and*dose* visible#light. # consideration#for#optimal#pH#adjustment# [64] .#
	At#low#concentrations#(<0.5#mM),#CDs#enhance#the#photocatalytic#degradation#of#target# Regarding# the# amount# of# photocatalyst# used,# an# optimal# dose# has# to# be# determined# #
	pollutants.# This# has# been# shown# with# a# dye# [81],# bisphenol# A# [82],# bisphenol# E# [83],### according# to# specific# characteristics# of# the# SW/SF# solution# and# nature# of# the# ! Oxygen*supply*
	4,4'Nbiphenol# [84].# Using# low# concentration,# the# enhancement# of# target# pollutant# photocatalyst#used.#For#example,#it#has#been#observed#that#the#higher#the#dose#(in#the#
	degradation#is#explained#by#the#adsorption#of#the#complex#CDNpollutant#onto#the#surface# range# 0.1# N# 0.5# g# L N1 ),# the# higher# the# photocatalytic# degradation# rate# of# PHE# [77] .# Molecular#oxygen#plays#an#important#role#on#the#photocatalytic#process:#its#main#role#is#
	However,# further# addition# of# TiO2# caused# the# light# obstruction# and# increased# filtration# of#the#photocatalyst#[84].#This#promotes#interactions#between#oxidant#species#and#target# to# act# as# an# electron# sink# for# photogenerated# electrons# (Figure# 1.4)# in# order# to# avoid#
	pollutants# [81].# Therefore,# a# high# inclusion# constant# between# CDs# and# HOCs# promotes# the# photocatalytic# degradation# of# HOCs.# Without# formation# of# this# complex,# a# delay# in# their# recombination# with# holes# [63] .# Moreover,# UV# photolysis# of# H2O2# formed# from# costs# [77] ,#decreasing#thus#the#costNefficiency#of#the#process.# oxygen#reduction#can#generate#additional#free# " OH#in#the#bulk#(Figure#1.4).#Oxygen#can#
	the#degradation#of#target#pollutants#can#occur#[84].#This#is#ascribed#to#the#higher#affinity# # also# either# hinder# or# support# the# reaction# according# to# degradation# mechanisms# of#
	of#CDs#onto#the#TiO2#surface#compared#to#organic#pollutants#and#competition#reactions# ! Irradiation*light* pollutants# [61] .# As# regards# to# SW/SF# solutions,# it# has# been# observed# a# significant#
	with# • OH.# increase#of#SWEP#residues#degradation#by#saturating#the#irradiated#suspension#with#air#
	The# nature# of# the# irradiation# light# (intensity# and# wavelength)# strongly# influences# the# bubbling# [65] .#
	Studies# using# high# CD# concentrations# reported# strong# inhibitory# effects.# Using# 83# mM# efficiency#of#the#process.#In#a#comparative#study,#Liu#et#al.# [75] #showed#that#solar#light#
	MCD,# very# low# efficiency# for# the# photocatalytic# degradation# of# pyrene# (PYR)# and# leads#to#faster#PCP#degradation#rate#compared#to#visible#light#(Table#1.1).#This#could#be# #
	phenanthrene#(PHE)#has#been#reported#[74].#It#has#also#been#shown#that#the#higher#the# explained#by:#
	CD# concentration# (in# the# range# 1# N# 5# mM),# the# lower# the# degradation# rate# of#
	pentachlorophenol# (PCP)# [71].# Similarly# to# solutions# containing# high# concentrations# of# • the# larger# amount# of# electron-hole# pairs# resulting# from# a# higher# light# strength#
	surfactants,# high# CD# concentrations# inhibit# the# photocatalytic# degradation# of# target# [75];#
	pollutants# by# occupying# all# active# sites# on# the# surface# of# the# photocatalyst# and# by# • the#larger#amount#of#photons#with#wavelengths#shorter#than#the#absorption#edge#
	providing#a#protective#environment#in#the#bulk#[74].# of#TiO2,#which#are#the#only#ones#to#result#in#reaction#[61];#
	carbamate#(SWEP)#residues,#the#process#was#more#efficient# by#using#SDS#compared#to#hexadecyltrimethylammonium#bromide#(cationic#surfactant)# # • PCP#photolysis#caused#by#the#UV#portion#of#solar#light#[75].##
	and# poly(oxyethylene)# dodecyl# ether# (C12E8,# nonTionic# surfactant)# [65].# Alkylphenol# # # #
	degradation# was# also# less# inhibited# with# SDS# than# with# nonTionic# surfactants# for# high# #
	surfactant#concentrations#[76].#In#a#similar#study#from#the#same#research#group,#three#
	nonTionic#surfactants#(at#10#mM,#much#higher#than#the#CMC)#have#been#tested#and#the#
	42#	41# 43#

3.2.'Technologies'based'on'Fenton'reaction'chemistry' 3.2.1.'General'considerations'

	Technologies# using# Fenton# reaction# chemistry# have# been# widely# studied# due# to# the#
	production# of# large# amounts# of# • OH# for# the# oxidation# of# organic# pollutants# [89].# The#
	effectiveness#of#these#AOPs#has#been#recently#reviewed#[44,90].#They#are#based#mainly#
	on#the#use#of#the#Fenton's#reagent,#which#is#a#mixture#of#hydrogen#peroxide#(H2O2)#and#
	ferrous

3.5.2.$Removal$efficiency$

  Only#few#authors#have#reported#kinetic#studies,#data#at#pilot#or#real#scale#and#used#real# SW/SF#solutions#[174,175].#In#the#area#of#biological#processes,#these#kinds#of#studies#are#

	Chapter 1
	Table&1.4.
	particularly# important# to# raise# understanding# of# biodegradation# mechanisms# and#
	efficiency.# However,# some# authors# have# investigated# biodegradation# effectiveness# by#
	using# batch# reactors# (Table# 1.4).# With# different# solution# characteristics# and#
	microorganism# cultures,# they# obtained# a# large# range# of# effectiveness.# Treatment# times#
	necessary# to# achieve# sufficient# removal# effectiveness# can# reach# several# weeks# (Table#
	1.4).# Biodegradation# effectiveness# strongly# depends# on# SW/SF# characteristics# such# as#
	64#

nature#of#the#target#pollutant#as#well#as#nature#and#dose#of#the#EA#(Table

#1

.4).#Different# surfactants# may# have# different# influence# for# a# same# bacterial# culture.# Likewise,# biodegradation# effectiveness# can# differ# for# a# same# surfactant# when# different# microorganisms# are# used# [173].# Therefore,# the# adaptation# and# acclimatization# of# microorganisms# to# the# mixture# surfactantNtarget# pollutant# is# an# important# parameter# [173].#Besides,#the#removal#of#(semiN)#volatile#HOCs#can#also#occur#through#volatilization# during#aerobic#treatment.# #

#Removal(effectiveness(for(biological(treatment(in(batch(reactors(of(solutions(containing(HOCs(and(extracting(agents.(

	Biodegradation experiment Target HOC (mg L -1 ) Extracting agent (g L -1 )	Treatment time	% Removal	Reference
		TX100 (10)		2
	Aerobic treatment.	anilines, benzenes,
	Microorganisms obtained from the contaminated soil	thiophenes and PAHs (pollutant concentration:	63 d		[176]
	during the SW step	85 -167 mg L -1 )

  .,,

	Chapter 1
	Only#few#authors#have#investigated#the#influence#of#EAs#on#biodegradation#mechanisms#
	and# kinetics.# Therefore,# it# is# difficult# to# discuss# results# obtained# and# to# highlight# clear#
	trends.# Certain# authors# [174,175]# have# assumed# that# some# EAs# (nonEionic# surfactants,#
	biosurfactants)#do#not#alter#HOC#degradation#kinetics#in#the#aqueous#phase.#Therefore,#
	based#on#Monod#equation,#the#following#model#has#been#proposed#(Eq.#8#and#9)#in#order#
	to#describe#substrate#and#biomass#evolution#during#the#biological#treatment#of#HOCs#in#
	the#presence#of#EAs#[174,175].#Kinetic#parameters#obtained#are#reviewed#in#Table#1.5.#
	Large# differences# have# been# obtained# for# maximum# specific# growth# rates.# This# is#
	ascribed#to#the#use#of#different#nature#of#microorganisms#(pure#culture,#mixed#culture)#
	and#substrate#(including#target#HOCs#and#EAs).#
	66#

Table $

 $

				Chapter 2
		1.8.#Important0operating0conditions,0target0pollutant0and0extracting0agent0
		characteristics0to0consider0according0to0the0choice0of0the0process0used0for0extracting0
		recovery0from0SW/SF0solutions.0CMC:0critical0micellar0concentration;0Km:0micellar0phase0/0
		aqueous0phase0partition0coefficient;0KCD:0complex0stability0(or0equilibrium)0constant0
			between0organic0compounds0and0cyclodextrins.0
		Process	Important target pollutant characteristics (optimal*)	Important EA characteristics (optimal*)	Important operating conditions
		Gas-liquid extraction	Henry constant (low), saturated vapor pressure (high), K m /K CD (low)	Henry constant (high), concentration (low), K m /K CD (low)	Limitation of foaming (hollow fiber membranes, vacuum processes)
	# #	Liquid-liquid extraction	Solvent-water partition coefficient (high), K m /K CD (low)	Solvent-water partition coefficient (low), concentration (low), K m /K CD (low)	Limitation of emulsification and amount of solvent used (hollow fiber membranes), highly hydrophobic solvent
				Concentration, K m ,
	#	Membrane processes	removal), K m Oil-containing mixture (for selective	concentration micelle size, CMC, effect on	fouling control Ultrafiltration (for micellar-enhanced ultrafiltration),
	#			polarization
	# #	Adsorption processes	Partition coefficient on the sorbent material (high), K m /K CD (low)	Partition coefficient on the sorbent material (low), (low) concentration, K m /K CD	Sorbent material and dose
	# !	Degradation processes	Degradation kinetic (fast), K m /K CD !	Degradation kinetic (slow), concentration, nature, K m /K CD	Optimized for selective degradation of target pollutants

Table ( 3.2.#Calibration#of#model#parameters.# Process (I=300mA)

 (

.1.(Apparent((pseudo3first(order)(rate(constant((kapp)(obtained(for(the(

	3.(Results(and(discussion%
	3.1.(Degradation(kinetics(of(single(compounds(
	The%first%experiments%were%performed%to%study%separately%the%oxidation%kinetics%of%the%
	main%components%of%a%synthetic%SW%solution,%according%to%the%current%intensity%supplied%
	during%AO%(PHE%as%model%target%pollutants,%TW80%as%extracting%agent%and%HA%as%model%
	soil% organic% matter).% Degradation% kinetics% of% PHE% and% TW80% as% well% as% mineralization%
	kinetics% of% HA% proceeded% according% to% a% pseudoOfirst% order% kinetic;% apparent% (pseudoO
	first%order)%rate%constants%(kapp)%are%reported%in%Figure%4.1.%The%degradation%of%PHE%was%
	studied%at%a%concentration%below%its%solubility%limit,%while%the%degradation%of%TW80%and%
	HAs%was%studied%using%concentrations%relevant%with%respect%to%the%issue%of%SW%solutions.%
	%
	.%
	%
	2.4.(Adsorption(experiments(
	The%adsorption%material%used%during%all%experiments%was%activated%carbon%fibers%from%
	Dacarb% (France)% with% a% specific% surface% area% of% 1200% m 2 % g O1 .% Glass% bottles% (500% mL)%
	containing%350%mL%of%SW%solution%and%various%amount%of%activated%carbon%(in%the%range% %
	0.1% -% 3.5% g% L O1 )% were% shaken% at% 20% rpm% in% a% rotary% shaker% for% 72% h% (preliminary%
	experiments% showed% that% the% equilibrium% is% reached% after% 72% h).% Control% tests% without% Figure(4
	activated% carbon% confirmed% that% PAH% loss% by% volatilization% or% degradation% was% lower%
	than%5%.%Analyses%were%performed%on%the%liquid%phase.%%

.2.(Effect(of(initial(HA(and(TW80(concentration((in(mgC(L 31

	Chapter 4
	rate% constant% of% TW80% degradation,% whereas% it% was% observed% that% the% degradation% of%
	PHE%in%single%compoundOcontaining%solutions%was%much%faster%than%the%degradation%of%
	TW80.% These% results% indicate% that% micelle% degradation% is% required% for% allowing% the%
	oxidation%of%a%PHE%molecule%entrapped%in%a%TW80%micelle.%The%locus%of%solubilization%of%
	target% molecules% in% micelles% depends% on% the% hydrophobicity% of% the% target% organic%
	compounds% [58].% Highly% hydrophobic% compounds% are% entrapped% in% the% very%
	hydrophobic%space%formed%at%the%middle%of%micelles,%while%the%locus%of%solubilization%of%
	less%hydrophobic%compounds%is%closer%to%the%external%shape%of%the%micelle%(hydrophilic%
	head%of%surfactants).%Therefore,%a%higher%protective%effect%of%micelles%might%be%expected%
	for%the%most%hydrophobic%compounds.%%
	%
	%
	Figure(4
	3.% By% using% high%
	current%intensity%and%various%concentrations%of%TW80%above%the%CMC,%it%was%observed%
	that%the%apparent%rate%constant%of%PHE%degradation%was%always%similar%to%the%apparent%
	188

)

(on(the(apparent(

.( 3.3.(Tween ® (80(degradation(kinetic(and(mechanism(during(the(AO(process(

	Due% to% the% crucial% role% of% surfactants% during% the% treatment% of% SW% solutions,% the%
	mechanisms%of%TW80%oxidation%during%AO%was%further%investigated%in%this%study.%First,%
	the% absolute% rate% constant% of% TW80% monomer% oxidation% by% BDD( • OH)% was% assessed% at%
	C<CMC% condition,% using% the% competition% kinetics% method% with% HBA% as% standard%
	competitor%(Figure%4.4).%The%value%determined%as%(2.97%±%0.60)%×%10 9 %M O1 %s O1 %showed%that%
	BDD( • OH)% react% quickly% with% TW80% monomers.% The% value% obtained% was% much% higher%
	than% the% one% reported% by% Mousset% et% al.% [13].% The% reason% might% be% that% this% previous%
	study%used%TW80%at%a%concentration%of%0.6%mM%(above%the%CMC),%while%the%formation%of%
	micelles%strongly%changes%the%oxidation%mechanism%and%kinetics.%

( Application( -( Reuse( of( soil( washing( solutions( by( selective( degradation( of( target(pollutants(during(AO(at(low(current(intensity(

	Chapter 4 Chapter 4
	3.4.( Degradation( mechanism( of( organic( compounds( solubilized( in( Tween ® ( 80T in% order% to% ensure% the% costOeffectiveness% of% the% process% [9].% Therefore,% treatment% of%
	containing(solutions(( synthetic%and%real%SW%solutions%by%AO%at%low%current%intensity%was%investigated%in%order%
	In% contrast% to% experiments% performed% at% 1000% mA,% low% current% intensity% (200% mA)% to%assess%the%degradation%of%target%pollutants%and%the%extraction%capacity%of%the%treated%
	allowed% reaching% higher% apparent% rate% constants% for% target% molecules% (HBA% or% PHE)% SW% solution.% Using% a% synthetic% SW% solution% (containing% PHE,% TW80% and% HAs),% it% was%
	degradation% than% for% TW80% degradation% (R>1)% (Figure% 4.5b% and% 4.5c).% This% does% not% observed%that%after%15%h%of%AO%at%50%mA,%87%%of%PHE%and%50%%of%TW80%was%removed%
	mean% that% surfactant% does% not% act% anymore% as% a% protective% environment% for% target% from%a%solution%containing%1%mM%TW80,%while%83%%of%PHE%and%only%19%%of%TW80%was%
	molecules% entrapped% inside( micelles.% It% can% be% explained% by% considering% the% micellar% /% removed% from% a% solution% containing% 5% mM% TW80% (Figure% 4.8).% This% confirmed% that% the%
	aqueous%phase%partitioning%coefficient%Km.%A%significant%amount%of%target%molecules%are% treatment% at% low% current% intensity% of% SW% solutions% containing% high% surfactant%
	not%entrapped%inside%micelles%and%are%directly%available%for%oxidation%by%BDD( • OH).%After% concentrations% is% a% promising% process% for% selective% degradation% of% target% pollutants.%
	oxidation% of% free% extraOmicellar% target% molecules,% other% molecules% can% be% continuously% Particularly,% this% is% consistent% with% results% from% the% Figure% 4.5a;% the% increase% of% the%
	released% in% the% aqueous% phase% according% to% Km.% This% transfer% process% is% not% a% kinetic% TW80% concentration% has% a% stronger% adverse% effect% on% TW80% degradation% kinetics% than%
	limiting%step,%since%the%relaxation%time%of%micelles%is%in%the%range%of%milliseconds%to%few% on%target%pollutant%degradation%kinetics,%due%to%the%decrease%of%the%ratio%Cmonomer%/%Cmicelle%
	seconds,% according% to% surfactant% concentration% and% nature% [61,62].% At% low% current% that%strongly%hinders%the%oxidation%of%TW80.%Besides,%the%decrease%of%the%TOC%was%very%
	intensity,%the%increase%of%the%availability%of%target%molecules%entrapped%in%TW80%micelles% low,%11%%at%1%mM%TW80%and%3%%at%5%mM%TW80,%indicating%a%low%mineralization%rate%of%
	is%more%controlled%by%this%pathway%than%by%the%degradation%of%micelles%(because%of%the%
	inhibition%of%micelle%oxidation%as%explained%previously).%This%phenomenon%is%consistent%
	with%the%higher%ratio%R%observed%by%using%HBA%as%target%molecule%since%this%latter%has%a%
	much%lower%Km%than%PHE%(having%a%higher%hydrophobicity),%leading%to%the%presence%of%a%
	larger%amount%of%free%extraOmicellar%compounds.%
	The%phenomena%observed%in%this%study%are%schematically%explained%in%Figure%4.7.%	• OH)%
	scavenging%effect%and%to%a%higher%concentration%of%free%extraOmicellar%HBA.%But,%overall,% %
	the% decrease% of% the% ratio% R% was% ascribed% to% the% strong% increase% of% TW80% degradation%
	kinetic% at% low% concentration.% At% C>CMC,% the% concentration% of% surfactant% monomer% is% Cmonomer% =% CMC% and% Cmicelle% =% [TW80]total% -% CMC% [3].% Besides,% the% availability% towards% oxidant%species%of%surfactant%monomers%is%expected%to%be%much%higher%than%the%one%of% 3.5.These% experiments% showed% that% high% TW80% concentration% and% low% current% intensity%
	surfactant%micelles,%due%to%(i)%the%steric%hindrance%phenomenon%described%previously%for% favor% the% selective% degradation% of% target% molecules% solubilized% in% a% TW80Ocontaining%
	micelles,% (ii)% the% spatial% configuration% of% micelles,% which% reduces% the% availability% of% the% solution,% due% to% the% strong% decrease% of% the% oxidation% rate% of% TW80% micelles.% These%
	hydrophobic%tail%of%surfactant%towards%oxidant%species.%This%is%why%the%increase%of%the% results% have% interesting% applications% for% the% treatment% of% SW% solutions.% In% the% case% of%
	ratio% Cmonomer% /% Cmicelle% at% low% TW80% concentration% strongly% promoted% the% oxidation% of% high% sequestration% of% pollutants% in% an% aged% contaminated% soil,% large% amounts% of% costly%
	TW80.% Lower% current% intensity% is% expected% to% enhance% this% trend% due% to% the% lower% extracting%agents%(such%as%TW80)%is%required%for%the%effective%removal%of%pollutants%from%
	availability% of% TW80% micelles% for% oxidation% by% BDD( • OH)% and% absence% of% mediated% soil%[63,64].%Then,%extracting%agents%must%be%recovered%and%reused%for%further%SW%steps%
	oxidation.%
	196	195

.( 3.6.( Comparison( with( selective( adsorption( on( activated( carbon( for( soil( washing( solution(treatment(and(reuse((

	Chapter 4 Chapter 4
	insufficient% removal% of% organic% compounds% entrapped% in% micelles% (mainly% at% low% 4.(Conclusions%
	activated% carbon% dose)% and% the% loss% of% TW80% by% adsorption% onto% the% activated% carbon%
	(mainly% at% high% activated% carbon% dose).% Thus,% it% was% observed% a% lower% extraction% Solubilization%of%organic%compounds%in%surfactantOcontaining%solutions%strongly%reduces%
	capacity%from%SW%solutions%treated%by%activated%carbon,%by%comparison%to%the%use%of%AO% their% availability% towards% oxidant% species% because% micelles% act% as% a% protective%
	at% low% current% intensity.% Moreover,% the% use% of% the% adsorption% process% requires% a% postO environment.%Moreover,%it%was%found%that%the%formation%of%micelles%has%strong%adverse%
	treatment%step%of%the%contaminated%sorbent%material,%while%the%use%of%AO%at%low%current% effects% on% surfactant% degradation% kinetics% during% AO,% due% to% a% lower% availability% of%
	intensity%allows%both%target%pollutant%degradation%and%SW%solution%recirculation.% surfactant% molecules% towards% • OH.% This% is% mainly% ascribed% to% a% steric% hindrance%
	% phenomenon;%the%BDD( • OH)%layer%generated%at%the%surface%of%the%BDD%anode%is%too%thin% (
	compared%to%the%size%of%micelles.%This%is%the%reason%why%current%intensity%and%surfactant%
	concentration% are% two% critical% parameters% to% consider.% Low% current% intensity% strongly%
	reduces%micelle%degradation%kinetics%due%to%the%steric%hindrance%phenomenon%combined%
	to% the% absence% of% mediated% oxidation% in% the% bulk.% The% decrease% of% the% ratio% Cmonomer% /%
	Cmicelle% at% high% surfactant% concentration% is% also% unfavorable% for% surfactant% degradation,%
	since% monomers% have% a% higher% availability% towards% oxidant% species% than% micelles.%
	Besides,%the%degradation%of%target%molecules%entrapped%in%micelles%occurs%either%through%
	the%degradation%of%micelles%followed%by%their%degradation%or%by%oxidation%of%free%extraO
	micellar% compounds.% Therefore,% selective% degradation% of% target% molecules% can% be%
	observed% by% implementing% low% current% intensity% and% high% surfactant% concentration.%
	These% operating% conditions% strongly% hinder% TW80% degradation,% while% free% (extraO
	micellar)% can% be% oxidized% and% continuously% released% from% micelles% according% to% the%
	partitioning%coefficient%Km.%Particularly,%this%study%reported%that%the%treatment%by%AO%at%
	50% mA% of% a% real% SW% solution% containing% PAHs% and% 5% mM% of% TW80% allows% the% selective%
	A% comparison% was% made% with% the% use% of% activated% carbon% for% selective% adsorption% of% degradation% of% PAHs% and% the% reuse% of% the% treated% SW% solution% with% similar% extraction%
	target%pollutants,%which%has%been%recently%proposed%for%extracting%agent%recovery%from% capacity%than%a%fresh%TW80%solution.%
	SW% solutions% [33,66-69].% Very% promising% results% were% obtained% for% the% selective% % %
	adsorption% of% 0.14% mM% of% PHE% in% a% binary% mixture% with% 5% mM% of% TW80.% For% example,%
	0.5%g% L O1 % of% activated% carbon% allowed% the% removal% of% 96%% of% PHE,% while% 97%% of% TW80%
	was% still% in% the% solution.% However,% the% efficiency% of% PAHs% adsorption% in% the% real% SW%
	solution% was% much% lower.% By% using% 1,% 2% and% 3.5% g% L O1 % of% activated% carbon,% the% removal%
	rate%of%the%sum%of%the%4%PAHs%analyzed%reached%46%,%72%%and%95%,%respectively,%while%
	200	199

the% decrease% of% the% extraction% capacity% of% the% treated% SW% solution% was% 25%,% 18%% and% 14%,% respectively.% The% decrease% of% the% extraction% capacity% is% ascribed% to% both% the%

  2013AREVA and Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), France)(6 months) Master's thesis -Supervisor: Prof. Hervé Gallard "Treatment of uranium mine water". On-site sampling protocols; chemical equilibrium; speciation; sorption and precipitation mechanisms. Research assistant -Supervisor: Dr. Assiyeh Tabatabai and Prof. Maria Kennedy "Ultrafiltration systems for seawater reverse osmosis pretreatment during periods of severe algal blooms". Solid-liquid interactions; membrane fouling; process engineering. Process engineering, water and soil analysis • Laboratory skills: implementation and monitoring of electrochemical, biological and membrane reactors; extraction of pollutants from soil; sampling protocols. • Metrology and analysis: liquid chromatography (detector: DAD, Fluo); gas chromatographymass spectrometry; ionic chromatography, ICP-OES, TOC analyzer; spectroscopy (UV-vis, Fluo, Raman); standardized methods for analysis of wastewater effluents and sludge, respirometry. • Modeling: development and calibration of dynamic models 1-D; chemical equilibrium and speciation (Minteq software). • Imaging: stereomicroscope. Computer skills • Programming: Matlab, Aquasim. • Operating systems: Microsoft Windows, MAC OS.

	2012	UNESCO-IHE, Delft (The Netherlands)
	(4 months)
	EXPERTISE!
	!
	SCIENTIFIC SKILLS

Naphtalene,

Pentachlorophenol,

Methyl(3,4-dichlorophenyl)carbamate,

Phenanthrene,

Pyrene

!soil!washing;!

!anodic!oxidation;!

!boronNdoped!diamond;!

!stainless!steel;!

!phenanthrene;!

!anthracene;!

!fluoranthene;!

!pyrene!

! all! the! organizations! that! provided! me! financial! support! to! perform! this! thesis! work:! (i)! the! European! Commission! through! the! Erasmus! Mundus! Joint! Doctorate! programme! ETeCoS 3 ! for! funding! this! 3! yearFPhD! (ii)! the! Italian! government!and!the!Mediterranean!Office!of!Youth!for!the!mobility!grant!obtained!for! the!mobility!in!Cassino!(Italy),!(iii)!the!University!ParisFEst,!through!the!doctoral!school! Sciences,!Ingénierie,!Environnement,!for!partial!funding!of!conference!fees.

• First#study#on#the#removal#of#humic#acids#from#water#by#electrochemical#AOPs#

• Modeling#of#TOC#removal#by#taking#into#account#sorption#and#oxidation#processes# Trellu%C.,%Oturan%N.,%Pechaud%Y.,%van%Hullebusch%E.D.,%Esposito%G.,%Oturan%M.A.,%Anodic%oxidation% of% surfactants% and% organic% compounds% entrapped% in% micelles% -% Selective% degradation% mechanisms%and%soil%washing%solution%reuse.%% %

Abstract(

This% study% pointed% out% that% the% formation% of% micelles% at% high% surfactant% concentration% strongly% modifies% oxidation% mechanisms% and% kinetics% of% organic% pollutants% during% anodic% oxidation% (AO)% using% boron% doped% diamond% (BDD)% anode.% While% the% nonOionic% surfactant% monomers% Tween ® % 80% (TW80)% reacts% quickly% with% BDD(

2.8.(Competition(kinetics(method%

The% absolute% rate% constant% of% TW80% degradation% by% BDD( • OH)% during% AO% was% determined%by%the%competition%kinetics%method%using%HBA%as%standard%competitor%(with% absolute% rate% constant% of% 1.63% ×% 10 9 % M O1 % s O1 % [START_REF] Hinds | Aerosol"technology[END_REF]).% BDD( • OH)% cannot% be% accumulated% in% the% electrochemical% celle% due% to% their% very% short% lifetime.% Therefore,% a% quasiOstationary% state% approximation% can% be% made% for% its% concentration% [START_REF]The$ stock$ solution$ was$ prepared$ L Q1 $of$commercial$HAs$in$milliQQ$water$at$pH$3.$This$solution$was$filtered$ /F$filter$$μm$as$pore$diameter).$Then,$HAs$were$ and$ the$ solution$ was$ centrifuged[END_REF].% This% allows% considering% pseudoOfirst% order% reaction% kinetics% for% the% oxidation% of% TW80% and% HBA% by% BDD( • OH).% Thus,%kinetic%analysis%allows%the%determination%of%the%apparent%rate%constants%(kapp)%and% then%the%absolute%rate%constant%(kabs)%by%means%of%the%Eq.%3% [13,54].% • AO$ resulted$ in$ higher$ removal$ rates$ and$ production$ of$ more$ biodegradable$ byQ products.$

• AO/BT$combination$gave$synergistic$effects,$leading$to$80%$COD$removal.$