ChemicalHRPsin wastewater 2
GangWu,JinfengWang,JinjuGeng,PhD StateKeyLaboratoryofPollutionControlandResourceReuse,SchooloftheEnvironment,Nanjing University,Nanjing,China
Chapteroutline
2.1Heavymetals....................................................................................................... 6
2.1.1Sourcesofheavymetalsinwastewater.................................................6
2.1.2Occurrenceandconcentrationsofheavymetalsinwastewater................7
2.1.3Migrationandtransformationofheavymetalsinwastewater.................10
2.2Persistentorganicpollutants.............................................................................. 10
2.2.1SourcesofPOPsinwastewater..........................................................12
2.2.2OccurrenceandconcentrationsofPOPsinwastewater.........................16
2.2.3MigrationandtransformationofPOPsinwastewater...........................16
2.3Pharmaceuticalandpersonalcareproducts........................................................ 18
2.3.1SourcesofPPCPsinwastewater........................................................18
2.3.2OccurrenceandconcentrationsofPPCPsinwastewater.......................19
2.3.3MigrationandtransformationofPPCPsinwastewater..........................19
2.4Endocrine-disruptingchemicals.......................................................................... 22
2.4.1SourcesofEDCsinwastewater..........................................................22
2.4.2OccurrenceandconcentrationsofEDCsinwastewater.........................23
2.4.3MigrationandtransformationofEDCsinwastewater...........................23
2.5OtherHRPs........................................................................................................ 23
2.5.1SourcesofotherHRPsinwastewater.................................................26
2.5.2OccurrenceandconcentrationsofotherHRPsinwastewater................26
2.5.3MigrationandtransformationofotherHRPsinwastewater...................27
2.6Summary........................................................................................................... 27 References............................................................................................................... 28 FurtherReading........................................................................................................ 39
Inrecentyears,moreandmorechemicalsaresynthesizedandusedtomeetpeople’s risinglivingstandards.ItisreportedthatthechemicalsregisteredundertheChemicalAbstractService(CAS)havebeenover140million(LiandSuh,2019).Once theyareusedanddischarged,thesechemicalswillexistinvariousenvironmentmedium.Humanbeingscanbeexposedtothesechemicals.Thisraisesaseriousissue forpeopletopaymoreattentionontheadverseeffectofthesechemicalson
High-RiskPollutantsinWastewater. https://doi.org/10.1016/B978-0-12-816448-8.00002-2 Copyright © 2020ElsevierInc.Allrightsreserved.
ecosystem.However,itisimpracticaltofocusonallthechemicalsregisteredinCAS (Whaleyetal.,2016).Someprioritizedchemicals,especiallyforthechemicalswith highrisk,shouldbegivenenoughattentionfirstly.
Chemicalhigh-riskpollutants(HRPs)refertothechemicalswithhighecological risktoecosystem(Rasheedetal.2019; Zhouetal.,2019).TheseHRPs(anthropogenicornatural)includebutarenotlimitedtoheavymetals,persistentorganicpollutants(POPs),pharmaceuticalsandpersonalcareproducts(PPCPs),andendocrine disruptingchemicals(EDCs)(LiandSuh,2019).Generally,wastewaterisoneofthe majorsinkfortheseHRPsoncetheybecomeconsumerproducts.Theoccurrenceof theseHRPsinwastewaterwillposesomepotentialadverseeffectonthedownside ecosysteminevitably(Tranetal.2017).Therefore,chemicalHRPsinwastewater shouldbegivenenoughattention.Understandingtheenvironmentalbehaviorand transformationcharacteristicsofchemicalHRPsisimportantfortheirremoval andriskreductioninenvironment.Inthischapter,thecategory,source,concentrations,migration,andtransformationofchemicalHRPsinwastewateraresummarizedindetail.ThisisbeneficialtofilltheknowledgegapofchemicalHRPsin wastewater.
2.1 Heavymetals
Heavymetalsrefertoanymetallicelementthathasarelativelyhighatomicmass(＞ 5g/cm3)andaretoxicorpoisonousevenatalowconcentration(Nagajyotietal., 2010).Heavymetals,whicharesignificantlytoxictoenvironmentalecology,mainly includecadmium(Cd),chromium(Cr),nickel(Ni),mercury(Hg),lead(Pb),manganese(Mn),copper(Cu),andzinc(Zn).Thesource,occurrenceandcontamination level,andfateofheavymetalsinwastewater,whichwillprovideaclearunderstandingonecologicalriskofmetalsinwastewatertoreaders,aresummarizedasfollows.
2.1.1 Sourcesofheavymetalsinwastewater
Industrialactivitiesareasignificantsourceofheavymetals(SantosandJudd,2010). Miningoperationsandoreprocessing,textiles,metallurgyandelectroplating,dyes andpigments,papermills,tannery,andpetroleumrefiningarethemainsourcesof heavymetalsinwastewater.Minewastewaterareoftenacidicandcontaindissolved heavymetals,suchasCd,Cr,Zn,andMn(HedrichandJohnson,2014),which mainlycomefrommineralprocessingandwashing(Zaranyikaetal.,2017).Plating rinsingprocessoftenintroducesCr,Cu,andHgintometallurgyandelectroplating wastewater(Hideyukietal.,2003).Metallizedcomplexedazodyeproductioncontributesthepresenceofmostoftheheavymetalsintextileswastewater(Edwards andFreeman,2010).Heavymetalsindyesandpigmentsmainlyarederivedfrom textilewarpsize,dye,andsurface-activeagents(HalimoonandGohsooYin, 2010).PapermillscontributetoahighconcentrationofHginwastewater(ElShafey,2010).Cristhedominantheavymetalintannerywastewater(Mella
etal.,2015).Heavymetalsfrompetroleumrefiningarederivedfromwasteoilrefiningcatalyst,whichmainlyincludeNi,Hg,Pb,Cr,andCd.Inaddition,some heavymetals,suchasCd,Cr,Hg,Ni,Pd,andAshavealsobeenrecognizedin municipalwastewatertreatmentplants.
2.1.2 Occurrenceandconcentrationsofheavymetalsin wastewater
Convergingfromdifferentsources,heavymetals,forexample,Cd,Cr,Ni,Hg,Pb, Mn,Cu,andZn,havebeenfrequentlydetectedinmunicipalandindustrialwastewater.Forexample, Ustun(2009) investigatedninemetals(Al,Cd,Cr,Cu,Fe, Mn,Ni,Pb,andZn)inwastewatertreatmentplants(WWTPs)inBursa(Turkey) for23monthsin2002and2007andfoundthatallthemetalsweredetectable. Teijon etal.(2010) assessedthecontaminantsleveloffourheavymetals(Cd,Ni,Hg,and Pb)inWWTPsandonlyAgwasoccasionallyunderthedetectionlimit.Despiteof thewidedistributionofdifferentheavymetalsinWWTPsingeologicallydifferent regions,theconcentrationlevelsofheavymetalsshowgreatvariation. Tables2.1 2.6 listthemainheavymetalsandtheirconcentrationsinbothmunicipal wastewaterandindustrialwastewaterlocatedindifferentcountries.
Aslistedin Table2.1,CdandPbshowhighdetectionfrequencyintheWWTPs of13countries.ConcentrationsofCdrangefromnotdetected(ND)to220 mg/L, withthehighestconcentrationintheWWTPsofTurkey.Meanwhile,concentrations ofPbrangefromNDto6860 mg/L,withthehighestconcentrationintheWWTPsof China.Inaddition,NiandCrwerefoundtohavehighlevelsinthewastewaterfrom GreeceandItaly,respectively.
Aslistedin Table2.2,Cdoftenoccursintheindustrialwastewatergeneratedfrom miningoperationsandoreprocessing,petroleumrefining,textilesproduction,metallurgyandelectroplating,dyesandpigments,papermills,andtannery.Concentrations ofCdinindustrialwastewaterrangefromNDto200mg/L,andmetallurgyandelectroplatingwastewateroftencontainshighconcentrationsofCd(upto200mg/L).
Asshownin Table2.3,Croftenoccursintheindustrialwastewatergenerated fromminingoperations,oreprocessing,petroleumrefining,textilesproduction, metallurgyandelectroplating,papermills,andtannery.ConcentrationsofCrinindustrialwastewatersvarygreatly,rangingfrom12 mg/Ltoover1700mg/L.Among thedifferenttypesofindustrialwastewater,tannerywastewateroftencontainsthe highestconcentrationsofCr(sometimesover500mg/L).
Hgoftenoccursintheindustrialwastewatergeneratedfromminingoperations,ore processing,metallurgy,andelectroplating. ConcentrationsofHginindustrialwastewater arenotveryhigh,usuallybelow1mg/L(Rahmanetal.,2017;Chojnackaetal.,2004).
Asshownin Table2.4,Nioftenoccursintheindustrialwastewatergenerated fromminingoperations,oreprocessing,petroleumrefining,textilesproduction, metallurgyandelectroplating,papermills,andtannery.ConcentrationsofNiinindustrialwastewaterrangefromNDtoover50mg/L,andmetallurgyandelectroplatingwastewateroftencontainhighconcentrationsofNi.
Table2.1 Concentrationsofheavymetalsinmunicipalwastewaterfromdifferentcountries.
Country
Poland7 70 <20n.d.10 2010 150 a Chipasa(2003);Kulbatetal.(2003)
Greece0.8 320 275n.d.11 77037 103 a Karvelasetal.(2003);Spanosetal.(2016)
Turkey20 22020 212 <0.120 2026 358 a Arslan-Alatonetal.(2007;Ustun(2009)
Italy0.2
31 Busettietal.(2005);Carlettietal.(2008);Hu etal.(2016)
Spain5 a 0.447.55.2 a Teijonetal.(2010)
USA0.4238.69n.d.7.397.055.05 Shaferetal.(1998);Raheemetal.(2017)
Cheng,2003;(Fengetal.,2018)
a daSilvaOliveiraetal.(2007)
France0.39 0.67
<
a -:nodatainthereference.
Buzieretal.(2006)
Edokpayietal.(2015)
AlEnezietal.(2004)
Chanpiwatetal.(2010)
Table2.2 ConcentrationsofCdinindustrialwastewaterfromdifferent countries.
SourceCodea Country
Mining operations andore processing
Petroleum refining
Textiles production
CACzech Republic
Concentrations(mg/ L)Reference
0.227
Sweden1.0
Egypt0 1
China0.002 0.022
MATunisia0.6
HAPakistan0.07 0.51
Malaysia0.409
Iran0.28
Rwanda0.05 0.14
Egypt40.65
Pakistan0.004 0.51
Metallurgy and electroplating
Dyesand pigments
SAPoland3.81
Dousova ´ etal.(2005)
HedrichandJohnson (2014)
Nosier(2003)
ChongyuLan(1992); Huetal.(2014)
BenHarizetal.(2013)
Alietal(2009); (Noreenetal.,2017)
Al-Zoubietal.(2015)
Ghorbaniand Eisazadeh(2013)
Sekomoetal.(2012)
Mahmouedetal., 2010
Alietal.(2009); Mahmouedetal. (2010)
Chojnackaetal. (2004)
Egypt100 200 Nosier(2003)
IARwanda0.05 0.14
PapermillsLAIndia0.01 0.78
TanneryJAPakistan0.02 0.59
Mexico22
India1.22
a CategorizingaccordingtoISO22447.
Sekomoetal.(2012)
Arivolietal.(2015); Chandraetal.(2017); Kumaretal.(2016)
Alietal.(2009);Tariq etal.(2006,2009)
Contreras-Ramos etal.(2004)
Chandraetal.(2009)
Asshownin Table2.5,Pboftenoccursintheindustrialwastewatergenerated fromminingoperations,oreprocessing,petroleumrefining,textilesproduction, metallurgyandelectroplating,papermills,andtannery.ConcentrationsofPbinindustrialwastewaterrangefromNDtoover60mg/L,andmetallurgyandelectroplatingwastewatercontainshighconcentrationsofPd.
Asoftenoccursintheindustrialwastewatergeneratedfromminingoperations, oreprocessing,andtextilesproduction.ConcentrationsofAsinindustrial
wastewatersrangefromNDto54mg/L(Dousova ´ etal.,2005;Sekomoetal.,2012; HedrichandJohnson,2014;Limetal.,2010).
2.1.3 Migrationandtransformationofheavymetalsinwastewater
Whenheavymetalsaredischargedintowastewater,thedistributionofmetalsbetweentheaqueousandthesolidphaseofwastewateroccursinevitably(Karvelas etal.,2003;Shaferetal.,1998). Karvelasetal.(2003) investigateddistributionof metalsbetweentheaqueousandthesolidphaseofwastewater,revealinghighexponentialcorrelationbetweenthemetalpartitioncoefficient(logKp)andthesuspendedsolidsconcentration.Inaddition,differenttransformationreactionscan occurinwastewatertreatmentprocesses.Methylationisacommontransformation reactionofheavymetalsbymicroorganisms.Forexample, Maoetal.(2016) investigatedthefateofHginWWTPsandfoundinfluentMeHgmasswasdegraded,indicatingthatWWTPsareanimportantsinkforsewage-borneHg.Inaddition, chelationreactionisanothercommonreactioninWWTPs.Heavymetalsinwastewatermayoccurasattachedtosuspendedsolidsviasurfaceboundorganicligands oradsorbedontoamajorinsolublematrixcomponent(e.g.,iron(III)oxide, aluminumhydroxideetc.),insolublesalts,inorganiccomplexsolids,orasfreeor organicallyboundsolubleforms.Theirspeciationmaydependontheinfluentmetal concentration,influentchemicaloxygendemand,hardness,alkalinity,andpHofthe wastewater(SantosandJudd,2010). Wangetal.(2003) investigatedtheinteractions ofsilverinwastewaterconstituentsandfoundthatchloride,sludgeparticulates,and dissolvedorganicmatter(DOM)hadaninteractionwithsilverandthevolumeof adsorptiontoDOMsubstantiallyaffectedbythevalueofpH.
Duetothetoxicityeffectofheavymetalstowardecosystem,theremovalofheavy metalsinWWTPsisneeded(Qureshietal.,2016).Generally,heavymetalsareresistanttobiodegradeinWWTPs,andsomephysicochemicaltreatmentmethodsrather thantraditionalbiologicaltreatmenthavebeenverifiedtobeeffectiveinremovalof heavymetalsfromwastewater(Karvelasetal.,2003).Forexample, FuandWang (2011) evaluatedthecurrentmethodsthathavebeenusedtotreatheavymetalwastewaterincludingchemicalprecipitation,ion-exchange,adsorption,membranefiltration, coagulation-flocculation,flotation,andelectrochemicalmethods.Theyfoundthat adsorptionandmembranefiltrationarethemostfrequentlystudiedprocessesforthe treatmentofheavymetalsinwastewater.Inaddition,biosorptionisanotherpromising methodtoeliminateheavymetalsinwastewater(VeglioandBeolchini,1997).
2.2 Persistentorganicpollutants
POPsrefertoonegroupoforganiccompoundscharacterizedwithhightoxicity,environmentalpersistence,transportingoveralongdistancethroughvariousenvironmentalmedium,andaccumulatinginbiologicalbodieseasily(Tieyuetal.,2005). ThewidelyknownadverseeffectsofPOPstowardhumanbeingsarecarcinogenesis,
Table2.3 ConcentrationsofCrinindustrialwastewaterfromdifferent countries.
SourceCode
Petroleum refining
India1.3 2.0
Spain0.2
China0.6 2.08
MATunisia3.3
Textiles production HAPakistan0.023 1.67
India0.0152 7.854
Turkey45.7 66.6
Metallurgyand electroplating
Shabalalaetal.(2017)
Mishraetal.(2008); Saha etal.(2017)
Jime ´ nez-Rodrı´guez etal. (2009)
Maetal.(2015)
BenHarizetal.(2013);Hu etal.(2014)
Alietal.(2009); Manzoor etal.(2006)
SanmugaPriyaand SenthamilSelvan(2017)
Ertugruletal.(2009)
Malaysia0.056 Al-Zoubietal.(2015)
Rwanda1.27 2.83
Sekomoetal.(2012)
SASaudi Arabia 93.2 Al-Shannagetal.(2015)
Argentina0.012 1.45
Maineetal.(2017) China1.6 16.7 Wuetal.(2017)
PapermillsLAIndia0.11
Chandraetal.(2017) TanneryJAPakistan0.037 592.2
Alietal.(2009); Tariqetal. (2006,2009); Tariqetal. (2005)
Mexico1475
India9.38
Contreras-Ramosetal. (2004)
Chandraetal.(2009)
Northern Ireland 49 Boshoffetal.(2004)
USA1.7 55
a CategorizingaccordingtoISO22447.
PolatandErdogan(2007)
tetratogenesis,andmutagenesiseffects(Dietzetal.,2018;Raffettietal.,2018). Generally,POPsincludepolychlorinatedbiphenyls(PCBs),polycyclicaromatichydrocarbons(PAHs),perfluorooctanoicacids(PFOA)andperfluorooctanesulfonate (PFOS),short-chainchlorinatedparaffins(SCCPs),andorganicpesticides(OCPs) (Baoetal.,2012;Gallistletal.,2017;Mremaetal.,2013).Furthermore,28substances orsubstancegroupsofPOPslistedintheStockholmconventiondeservemoreattention(Fernandesetal.,2019;MagulovaandPriceputu,2016;Weietal.,2007;Zapata etal.,2018).Inthissection,thesource,occurrenceandcontaminationlevel,andfate
Table2.4 ConcentrationsofNiinindustrialwastewaterfromdifferent countries.
SourcesCode a Country
Mining operations andore processing
CASouth Africa
Concentration
0.6 1.3
Sweden0.3
India <0.001
China1.03
Shabalalaetal.(2017)
HedrichandJohnson (2014)
Sahaetal.(2017)
Huetal.(2014)
Petroleum refining MATunisia4 BenHarizetal.(2013)
Textiles production
Metallurgyand electroplating
HAPakistan0.67 Alietal.(2009)
Malaysia <0.001 Limetal.(2010)
India0.5 3 SanmugaPriyaand SenthamilSelvan(2017)
Turkey38.1 47.9 Ertugruletal.(2009)
Poland0.0693 0.11 Al-Zoubietal.(2015, CempelandNikel(2005)
SASaudi Arabia 57.6 Al-Shannagetal.(2015)
Argentina0.004 0.101
Maineetal.(2017)
Poland0.218 Chojnackaetal.(2004)
India6.704 Radhakrishnanetal. (2014)
PapermillsLAIndia0.06 3.30
Arivolietal. (2015);,Chandraetal. (2017); Kumaretal. (2016)
TanneryJAPakistan0.116 0.671 Tariqetal.(2006,2009); Tariqetal.(2005)
India0.44 Chandraetal.(2009)
a CategorizingaccordingtoISO22447.
ofPOPsinwastewater,whichwillprovideaclearunderstandingonecologicalriskof POPsinwastewatertoreaders,aresummarizedasfollows.
2.2.1
SourcesofPOPsinwastewater
ThesourcesofdifferentcategoriesofPOPsaregenerallydifferent.Thepresenceof pesticidesinWWTPsismainlyduetononagriculturalusages,suchasgrassmanagement(golfcourses,educationalfacilities,parks,andcemeteries),industrial vegetationcontrol(industrialfacilities,electricutilities,roadways,railroads,pipelines),publichealth(mosquito-abatementdistricts,rodent-controlareas,andaquatic areas),andnonagriculturalcropssuchascommercialforestryandhorticultureand plantnurseries(Kock-Schulmeyeretal.,2013).
Table2.5 ConcentrationsofPbinindustrialwastewaterfromdifferent countries.
SourceCode a
Miningoperations andore processing
CASouth
Africa <0.03
Ghana0.140
China0.087 1.57
Shabalalaetal.(2017)
Acheampongetal. (2010)
ChongyuLan(1992); Maetal.(2015)
PetroleumrefiningMATunisia5 BenHarizetal.(2013)
TextilesproductionHAPakistan0.1 0.49 Alietal.(2009); Noreenetal.(2017)
Malaysia0.08 0.643
Metallurgyand electroplating
Al-Zoubietal.(2015); Limetal.(2010)
Rwanda0.25 0.67 Sekomoetal.(2012)
SAPoland1.52 10 3 Chojnackaetal. (2004)
China67.8 Wuetal.(2017)
PapermillsLAIndia0.22 1.05
TanneryJAPakistan0.196 0.872
Mexico9.1
Chandraetal.(2017); Kumaretal.(2016)
Tariqetal.(2006, 2009);Tariqetal. (2005)
Contreras-Ramos etal.(2004)
India0.34 Chandraetal.(2009)
a CategorizingaccordingtoISO22447.
ThewideuseofPCBsaspaints,inks,lubricants,andotheradditives,aswellas insulationfluidsintransformersandcapacitorsduring1950 1983isthedominant sourceofPCBsintovariousenvironmentalmedium,especiallyinwastewater (Rodenburgetal.,2011).IthasbeenindicatedthatoldWWTPsremainadominant sourceofPCBstotheenvironmentalthoughtheproductionhasbeenbannedfor 4decades(NeedhamandGhosh,2019).
ThesourcesofPAHsarecomplexandcanbedividedintonaturalandanthropogenicones.Generally,PAHsareformedbytheincompletecombustionofcoal,oil,tar, gas,wood,garbage,andcharbroiledmeatduringnaturaloranthropogenicprocesses. OthersourcesofPAHsincludeheavypetroleum,dieselfuels,kerosene,aviationfuel, heavyhome-heatingoils,oils,wasteoil,andmanylubricants(Khadharetal.,2010). Inapresentstudy,cokeproductionhasbeenidentifiedasoneofthemajorsourcesof China,whichcontributes16%ofthetotalPAHsinChina(Zhangetal.,2012).
PFOAandPFOSarewidelyusedintextile,fire-fightingfoam,leather,foodpackaging,carpet,floorgrinding,andshampoo.Theproduction,marketing,anduseof
Table2.6 ConcentrationsofPOPsinwastewaterfromdifferentcountries.
OCPsAldrinGreeceMunicipal wastewater 10 a Katsoyiannisand Samara(2004)
SpainMunicipal wastewater n.d.120 Barco-Bonilla etal.(2013)
DieldrinGreeceMunicipal wastewater 278.9 Katsoyiannisand Samara(2004)
CyprusMunicipal wastewater 12n.d. Fattaetal.(2007)
p,p’-DDDChinaMunicipal wastewater 2.42n.d. Lietal.(2008)
p,p’-DDTChinaMunicipal wastewater 13.55.23 Lietal.(2008)
DiuronSpainMunicipal wastewater n.d.250 Barco-Bonilla etal.(2013)
SpainMunicipal wastewater 93127Kock-Schulmeyer etal.(2013)
PAHsNaphtaleneSpainMunicipal wastewater 45003490 Sanchez-Avila etal.(2009)
AcenaphtylSpainMunicipal wastewater 30n.d. Sanchez-Avila etal.(2009)
FluoreneSpainMunicipal wastewater n.d.250 Barco-Bonilla etal.(2013)
SpainMunicipal wastewater 1150200 Sanchez-Avila etal.(2009)
ChinaCokingwastewater700,000350,000 Zhangetal.(2012)
ChinaPetrochemical wastewater n.d.1080 Wangetal.(2007)
PCBsPentachlorobiphenylUSAMunicipal wastewater 0.5950.397 PhamandProulx (1997)
TetrachlorobiphenylUSAMunicipal wastewater 0.6300.229 PhamandProulx (1997)
NaphthaleneChinaMunicipal wastewater 205.656.7 Tianetal.(2012)
AcenaphtheneChinaMunicipal wastewater 5.30.4 Tianetal.(2012)
FluoreneChinaMunicipal wastewater 23028.9 Tianetal.(2012)
PFOASingaporeMunicipal wastewater 16.35 Yuetal.(2009)
ChinaMunicipal wastewater 46,0002,200,000 Chenetal.(2012)
DenmarkMunicipal wastewater 18.62 Bossietal.(2008)
PFOSSingaporeMunicipal wastewater 13.97.3 Yuetal.(2009)
ChinaMunicipal wastewater 88.937.9 Chenetal.(2012)
DenmarkMunicipal wastewater 3.31.5 Bossietal.(2008)
a -:nodatainthereference.
commercialproductscontainingPFOAandPFOSmaterials,aswellastheuseof productscontainingPFOAandPFOSwillcausethesechemialsoccurinwastewater treatmentsystemthroughsurfacerunoffandsewernetworks(Guoetal.,2010).
SCCPsareaclassofhighlycomplextechnicalmixtures,andcontainagreatvarietyofisomers,diastereomers,andenantiomers.Generally,SCCPsareproducedin polyvinylchloride,flameretardant,andmetalcuttingfluidindustries(Weietal., 2016).DischargeofSCCPsintowastewatercanoccurduringproduction,usage, anddisposalorrecyclingoftheseproducts(Zengetal.,2012).
2.2.2 OccurrenceandconcentrationsofPOPsinwastewater
TheconcentrationsofPOPsindifferentWWTPsvarygreatly. Table2.6 summarizes theinformationregardingtheoccurrenceandconcentrationsofPPCPsinwastewaterindifferentcountries.
TheconcentrationsofmostofPOPssuchasOCPs,PAHs,PCBs,andPFOSlisted in Table2.6 rangefromng/Lto mg/L.OnlyPFOAreportedby Chenetal.(2012) in municipalwastewaterinChinaisuptotheconcentrationof2.2mg/L.Comparingthe concentrationofPOPsinmunicipalwastewaterwiththeminindustrialwastewater, themarkedlyhigherconcentrationdetectedinindustrialwastewatercanbefound. Forexample,theconcentrationofPAHsinmunicipalwastewaterrangesfromND to1150ng/L.However,theconcentrationofPAHsincokingwastewateris 700,000ng/Land35,000ng/Lforinfluentandeffluent,respectively.Inpetrochemical wastewater,theconcentrationofPAHsineffluentisupto1080ng/L.Moreover,the concentrationsofPOPsinwastewateraregeographicallydifferent.Forexample,dieldrinhastheconcentrationsof27and12ng/Lintheinfluentofmunicipalwastewater inGreeceandCyprus,respectively,whilePFOShastheconcentrationsof7.3,37.9, and1.5ng/LineffluentinSingapore,China,andDenmark,respectively.Higherlevels ofPFOScanbedetectedinWWTPsofChinathanintheothercountries,becauseindustrialwastewaterisoftendischargedintoWWTPsafterpretreatmentinChina.Itis worthnotedthatsomePOPs,suchasdiuron,aldrin,fluorene,andPFOA,havehigher concentrationsineffluentthanthoseininfluent,whichcouldbeexplainedbythat POPsarestoredintheactivatedsludgeofWWTPsandthenreleasedintotheaqueous phaseduringwastewatertreatmentprocess(Chenetal.,2012).
2.2.3 MigrationandtransformationofPOPsinwastewater
Inwastewater,hydrolyzation,volatilizationtogasphase,photolysis,adsorptionto activatedsludgeorsuspendedparticles,andbiodegradationprocessarethemajor migrationandtransformationroutesforPOPs(Kwonetal.,2014).Dependingon thechemicalpropertiesofPOPs,differenttypesofPOPsundergodifferentmigrationandtransformationprocesses.
BiodegradationandadsorptionarethemainremovalroutesforOCPsinwastewater.Forexample, Kwonetal.(2014) investigatedthefateoflindaneinthe WWTPsandfoundthatsorptiononprimarysludgesolidswasthemajorremoval
mechanism.Asignificantlinearcorrelationbetweenthecompound’spartitioncoefficientandtheorganicfractionofprimarysludgewasfound. Stasinakisetal.(2009) investigateddiuronbiodegradationinactivatedsludgebatchreactorsunderaerobic andanoxicconditions.Theresultsindicatedthatalmost60%ofdiuronisbiodegradedunderaerobicconditions,andtheexistenceofanoxicconditionsincreased diuronbiodegradationtomorethan95%.
PCBscanbeadsorbed,biodegraded,andbioaccumulatedduringwastewater treatmentprocesses.Becaus eoftheirhighlipidsolubility,PCBshavemuchhigher concentrationsinsedimentsandsuspendedsubstancesthaninwastewater(Balasubramanietal.,2014).AccordingtotheKow,(thevalueisgenerallylargerwhen PCBsiswithahighnumberofchlorineatoms)PCBswithalownumberofchlorineatomspresentedloweradsorptionstrengthinsedimentscomparedwithahigh numberofchlorineatoms.ItisnoteworthythatPCBsinsedimentscanberereleasedintowaterbodiesthroughthemethodofbiodegradation(Balasubramani etal.,2014).PlentyofstudieshaveinvestigatedthebiodegradationofPCBsby aerobicmicroorganismsinactivatedsl udge,andtheresultsindicatedthatPCBs withone,two,three,andfourchlorineatomshavegoodbiodegradationperformance,whileothercounterpartPCBs areresistanttobebiodegraded( Bergqvist etal.,2006 ).Thecounterpartswithhighcontentchlorineatomcanbedegraded inanaerobicconditionsth roughreduceddechlorina tion,whichisbeneficialto theformationoflowchlorinatedbiphenyls.Furthermore,lowchlorinatedbiphenylswillbedegradedbyaerobicdegradation( Balasubramanietal.,2014 ).Due tothehighlipidsolubilityofPCBs,theyt endtoaccumulateinfattytissues.The accumulationofPCBsinfattytissueisinfluencedbyexposurelevel,exposure time,molecularstructureofthecompound,andtypeofsubstitution.Generally, PCBswithmorechlorineatomsare conductivetotheaccumulation( Dinn etal.,2012).
PAHsgenerallyareremovedpartiallyinwastewatertreatmentsystem.Themain mechanismsforPAHsremovalintheseprocessesincludeadsorptionontosuspended solidsandsludge,biotransformation(biodegradation),andvolatilization.Other abioticdegradationroutes,suchasphotolysisandhydrolyzation,mayalsooccur naturally.Inconventionalactivatedsludgesystem,significantamountsofPAHs removalratehavebeenobserved(Caoetal.,2018).AdsorptionofPAHstobacterial cells,includingactivesurfacereactionandnonspecificpartitioningphenomena,has beenconsideredasthemostlikelyremovalprocess(Zhangetal.,2019).BiotransformationofPAHsmainlyincludesmetabolicreactiononmixedsubstrateandcometabolicreaction.Inmetabolicreaction,microorganismsusetargetpollutants togetherwithothercompoundsasenergyand/orcarbonsourceforcellmaintenance, growth,andreproduction.Microorganismsutilizeothersubstratesastheirenergy and/orcarbonsourceforcometabolicreaction.Furthermore,unspecificenzymes, suchasmonooxygenases,dioxygenases,andhydrolases,orcofactors,producedduringtransformationofgrowthsubstratecoulddegradethemicropollutantsbysidereactions.Generally,themechanismofaerobicbiodegradationofPAHsisthat dioxygenaseenzymesinitiallyoxidizethebenzeneringsofPAHsfortheformation
ofcis-dihydrodiols,andthenbioconvertedtodehydroxylatedintermediatesbydehydrogenationandendedwithCO2 andH2Oproductions(Gongetal.,2017).
Accordingtothepreviousstudies,PFOAandPFOSseemnottobeconsistently removedduringsecondarybiologicaltreatmentduetothehydrophobicandoleophobic(Arvanitietal.,2012).Insomecases,theconcentrationsofspecificPFOAand PFOSintreatedwastewaterarehighercomparedtorawsewage(Loganathanetal., 2007),indicatingtheirformationviabiotransformationofprecursorcompounds.In apreviousstudy, Keyetal.(1998) reportedthatPFOSismicrobiologicallyinertunderaerobicconditionsbyapurebacterialculture.Recently, Kwonetal.(2014) foundthatPFOScanbedecomposedupto67%byaspecificmicroorganism(Pseudomonasaeruginosa),buttheformationoffluorideionfromPFOSdegradationwas notobserved.However,PFBSandPFHxSweredetectedasminorproducts.The biodegradationandtransformationofPFOAhavebeenexaminedby Liouetal. (2010) employingfivedifferentanaerobicmicrobialcommunities,whichoriginated fromWWTPs,industrialsediment,agriculturalsoil,andsoilsoftwofiretraining areas,separately.Moreover,theresultsindicatedthatPFOAisbiologicallyinactive underalltheexaminedconditions.Sorptioncouldbeanotherimportantmechanism forPFOAsremovalduringwastewatertreatment.Generally,distributioncoefficients (Kd)andorganiccarbondistributioncoefficients(Koc)forPFOSandPFOAare recognizedasimportantfactorsonadsorptionvolume(SinclairandKannan,2006).
2.3 Pharmaceuticalandpersonalcareproducts
PPCPscontainawiderangeoforganiccompounds,includingpharmaceuticalssuch asantibiotics,hormones,analgesics,andantiinflammatorydrugs,antiepileptic drugs,bloodlipidregulators, b-blockers,contrastmedia,cytostaticdrugs,licitstimulants,andillicitdrugs.Moreover,personalcareproductsmainlyconsistofantimicrobialagents/disinfectants,syntheticmusks/fragrances,insectrepellants, preservatives,andsunscreenUVfilters(LiuandWong,2013).Theyhaveraisedsignificantconcernsinrecentyearsfortheirpersistentinputandpotentialthreatto ecologicalenvironmentandhumanhealth(Daietal.,2014;Wuetal.,2019).This sectionintroducesthesource,occurrence,concentrations,migration,andtransformationofthesePPCPsinwastewater,whichwillprovideaclearunderstanding onecologicalriskofPPCPsinwastewatertoreaders.
2.3.1 SourcesofPPCPsinwastewater
Aspeoplepaymoreattentiontotheirownhealth,pharmaceuticalsareproducedin largequantities.Generally,thepharmaceuticalfactoryisanimportantsourcefor pharmaceuticalintoenvironmentwaterbodies(Leietal.,2010).Inaddition,alarge volumeofpharmaceuticalsisusedasveterinarydrug,whichareoftenoverusedto keeppoultryhealthy.Therefore,someproportionofpharmaceuticalsareexcretedin poultrydroppingsandthenreleasedintothesurroundingwater(Jiangetal.,2013).
Inanalogy,forhumanbeings,manydrugsareexcretedwithoutmetabolismand consequentlyenterwastewatereitherintheirparentormetabolizedform(FattaKassinosetal.,2011). VienoandSillanpaa(2014) pointedthatonly6% 7%of diclofenacisabsorbedwhiletherestiswashedofftheskinorgluedtotheclothing. Furthermore,65% 67%ofdiclofenacisexcretedbyurine,and20% 30%ispresentinfeceswithaparentdrugormetaboliteforms.
Forpersonalcareproducts,differentusedpersonalcareproductscomefrom differentsourcesgenerally.Antimicrobials/disinfectantsaregenerallyusedforthe therapeutictreatmentofbacterialdiseasesforhumanbeings,andsomearealso usedforanimals,suchascattle,fish,andpoultryforgrowthpromotionandfordiseasetherapyandtreatment(Miaoetal.,2004).Therefore,thesourceofantimicrobials/disinfectantsisbasicallythesameasthesourceofpharmaceuticalsin wastewater.Forsyntheticmusks/fragrances,thelow-costsubstitutesfornatural muskshavebeenlargelyusedasfragrancesinmostofcleaningagentsandcosmetic products(Liuetal.,2014).Forpreservatives,theygenerallyareusedinawiderange oftoothpastes,cosmetics,hairstylingproducts,andsunscreens(Kimuraetal., 2014).MostofPPCPsarereleasedintothewastewaterthroughsewerlinessystem.
2.3.2
OccurrenceandconcentrationsofPPCPsinwastewater
Aspresentedin Table2.7,theconcentrationofPPCPsinwastewaterrangedbetween ng/Land mg/Llevel.Generally,theconcentrationofPPCPsinhospitalwastewater orpharmaceuticalwastewaterismarkedlyhigherthanthatitinmunicipalwastewater.SimilartrendfortheconcentrationofPPCPs,suchasciprofloxacin,diclofenac,andnaproxen,inmunicipalwastewater,hospitalwastewater,and pharmaceuticalwastewatercanalsobefound.Indifferentcountries,theconcentrationofdifferentPPCPsinwastewaterisdifferent.Forexample,theconcentrationof sulfamethoxazoleinwastewaterinSingaporeandChinawaswithsignificantdifference.TheconcentrationofciprofloxacininwastewaterinKoreaandCroatiaisatthe samelevel.However,theconcentrationofatenololintheUnitedKingdomisobviouslyhigherthanthatinGermany.Similartrendcanbefoundforbezafibratein ChinaandGermany.TheconcentrationofPPCPsdecreasesduringwastewatertreatmentprocess,whichdemonstratesthatwastewatertreatmentplantsplayaconsiderablerolefortheremovalofPPCPs.
2.3.3 MigrationandtransformationofPPCPsinwastewater
PPCPscanberemovedorberetainedinWWTPsafterenteringthewastewater.Generally,biodegradation,adsorption,volatilization,hydrolyzation,andphotolysisarethe likelytransformationroutesinwastewatertreatmentprocess(LiandZhang,2010). FormostofPPCPs,removalcausedbyvolatilizationisinsignificantattributedto therelativelygreatermolecularweight(Yangetal.,2017a).Similarly,photolysis generallycannotaccountforamentionableproportionofremovalforPPCPsin WWTPs.ThiscanbeexplainedbytheturbidityinWWTPsthatisunbeneficialto
Table2.7 ConcentrationofPPCPsinwastewaterindifferentcountries.
CategoryCompoundCountry
AntibioticsSulfamethoxazoleSingaporeMunicipal wastewater 1172311.3 Tranetal.(2016)
ChinaMunicipal wastewater 340.764.1 Benetal.(2018)
FranceHospital wastewater a 2100 Dinhetal.(2017)
ChinaBreeding wastewater a 40 Zhietal.(2018)
Republic ofKorea Pharmaceutical wastewater 166,000137,000 Simetal.(2011)
SulfamethazineSingaporeMunicipal wastewater 802.8135.9 Tranetal.(2016)
CiprofloxacinRepublic ofKorea Hospital wastewater 19803080 Simetal.(2011)
Republic ofKorea Pharmaceutical wastewater 87101860 Simetal.(2011)
CroatiaMunicipal wastewater 2610 a Sentaetal.(2013)
Nonsteroidal antiinflammatory drugs
DiclofenacChinaMunicipal wastewater 290190 Suietal.(2011)
USAMunicipal wastewater 28012 Yuetal.(2013)
Canada216,000214,000 Lajeunesseand Gagnon(2007)
NaproxenUKMunicipal wastewater 838370 KasprzykHordernetal. (2009)
FinlandMunicipal wastewater 4900840 Lindqvistetal. (2005) Republic ofKorea Pharmaceutical wastewater 59,70013,300 Simetal.(2011)
AntiepilepticdrugsCarbamazepineGermanyMunicipal wastewater 660740 Wicketal.(2009)
UKMunicipal wastewater 950826 KasprzykHordernetal. (2009)
b-blockersAtenololGermanyMunicipal wastewater 540300 Wicketal.(2009)
UKMunicipal wastewater 12,9132870 KasprzykHordernetal. (2009)
ContrastmediaIohexolChinaMunicipal wastewater 8.28.16 Yangetal. (2017b)
LicitstimulantsCaffeineChinaMunicipal wastewater 1083.65 Yangetal. (2017b)
IndiaMunicipal wastewater 75913 Mohapatraetal. (2016)
LipidregulatorsBezafibrateChinaMunicipal wastewater 72.611.4 Mohapatraetal. (2016)
GermanyMunicipal wastewater 1500500 Gurkeetal.(2015)
a ,nodatainthereference.
phototransformation.Biodegradationgenerallyplaysacrucialroleindegrading PPCPs.Forexample,biodegradationofdiclofenacaccountedforabout80%forthe totalremovalvolumeinactivatedsludge(Wuetal.,2019).ForotherPPCPssuch asantibiotic,theremovalattributedtoadsorption,hydrolyzation,volatilization,and biodegradationprocesshasbeenexploredby LiandZhang(2010) andtheresults demonstratedthatotherthanbiodegradation,otherremovalroutesplayedalimited role(less20%)fortheremovalofantibioticinwastewater.ItisnotedthatPPCPs generallycannotbeeliminatedcompletelybybiologicaltreatmentmethods(Tran etal.2017).Someadvancedtreatmentmethodssuchasadvancedoxidationprocesses (Zhangetal.,2016b;Fuetal.,2019a)anddisinfection(Zhangetal.,2015b)arepromisingapproachestoeffectivelyremovePPCPsinwastewatereffluents.
DuetoPPCPscannotbemetabolizedcompletelyinwastewatertreatmentsystem, someintermediateproductsaregeneratedinwastewatertreatmentprocess(Gulde etal.,2016;Helblingetal.,2010).Withthedevelopmentoftechnologyinidentifying transformationproducts,microbialmediatedtransformationproductsofPPCPshave increasinglyreceivedattention.Sometransformationproductshavebeendetectedand quantifiedinWWTPsconcurrentwithparentPPCPs(Beretsouetal.,2016).Inaddition,sometransformationproductshavebeenfoundtobemoretoxicantthanparent compounds(Gaoetal.,2018;EscherandFenner,2011).Therefore,transformation productsandparentcompoundsshouldreceiveequivalentattention.
2.4 Endocrine-disruptingchemicals
Endocrine-disruptingcompoundsreferto‘‘exogenoussubstancesthatalterfunction(s)oftheendocrinesystemandconsequentlycauseadversehealtheffectsin anintactorganism,oritsprogeny,or(sub)-populations’’(WHO/IPCS,2002).Therefore,anycompoundsthatcantriggerreproductivechangecanberegardedasEDCs. Generally,EDCsconsistofestrogensandsomeplantmetabolites,somepesticides suchasdichlorodiphenyltrichloroethanedieldrin,andlindane,industrialchemical productssuchasdioxinsanddioxin-likecompounds,theformerlywidelyused shipantifoulingagenttributyltin,organotincompoundsusedinpolyvinylchloride waterpipemanufacture(Aurioletal.,2006).Inthissection,themainsources,concentration,andfateofEDCsinwastewaterareintroduced.
2.4.1 SourcesofEDCsinwastewater
ThesourceofEDCscategorizedaspesticideisgenerallyagriculturalareasandsurfacerunoff.Inaddition,innonagriculturalcropssuchascommercialforestryand horticultureandplantnurseries,pesticidecanalsobewidelyusedanddischarged intowastewater(Kock-Schulmeyeretal.,2013).ForEDCslikehormones,pharmaceuticalfactoriesareanimportantpointsource.Inaddition,hospitalwastewaterand humanandanimalexcretionarealsoimportantsources(HamidandEskicioglu, 2012).ForEDCslikeindustrialchemicalproducts,themajorsourceforthemis
