229 11 Removal of Endocrine Disruptors and Pharmaceuticals during Water Treatment Shane A. Snyder, Hongxia Lei, and Eric C. Wert 11.1 INTRODUCTION Over the past decade a great amount of interest has arisen regarding the occurrence andfateoftraceorganiccontaminantsintheaquaticenvironment.Ofparticular concern are human hormones and pharmaceuticals, many of which are ubiquitous contaminants in conventional municipal wastewater treatment plant efuents when measured with ng/L detection limits. As analytical procedures and bioassay tech- niques become more readily available and increasingly sensitive, new contaminants will be discovered. The presence or absence of any chemical in a wastewater efu- entisessentiallyafunctionofanalyticaldetectioncapability.Thisposesaunique challengefordrinkingwatertreatmentplantsintentontheremovaloforganiccon- taminants,ascompleteremovalismerelyareectionofreportinglimits.Theproj- ect described in this chapter was designed to investigate the attenuation of a group of structurally diverse emerging contaminants by conventional and advanced water treatment processes. Contents 11.1 Introduction 229 11 .2 Background 230 11.3 Selection of Target Compounds 232 11.4 Analytical Methods 234 11.5 Bench-Scale Evaluations 235 11.5.1 Bench-Scale Experimental Procedures 235 11.5.2 Results from Bench-Scale Studies 237 11.6 P ilot-Scale Evaluat ions 245 11.6.1 Pilot-Scale Experimental Procedures 245 11.6.2 Results from Pilot-Scale Studies 246 11.7 Full-Scale Evaluations 249 11.8 Conclusion 252 Ack nowledg ments 254 References 255 © 2008 by Taylor & Francis Group, LLC 230 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems Thesedatarepresentaportionofthendingsfromastudysponsoredbythe American Water Works Association Research Foundation (AwwaRF) entitled “Removal of EDCs and Pharmaceuticals in Drinking and Reuse Processes” (Project #2758). This project sought to determine the treatment efcacy of various processes atbench,pilot,andfullscalefortheremovalofemergingcontaminantsbymonitor - in g the concentration decrease of the parent compounds. Reaction byproducts and thecorrespondingstructuralchangeswerebeyondthescopeofthisstudy;however, oxidative processes generally do not result in appreciable mineralization, and reac- ti on byproducts are expected. This chapter focuses on ndings related to oxidation, magnetic ion-exchange, and activated carbon. For the sake of brevity, experiments using Colorado River water (CRW) will be the highlight of this chapter while noting AwwaRF Project 2758 investigated several natural waters. This study shows that the majority of emerging contaminants can be readily oxidized using ozone or ultraviolet (UV)-advanced oxidation. Free chlorination effectively removed more target compounds than chloramination. Magnetic ion- exchange (MIEX ® )providedminimalcontaminantremoval;however,contaminants that were negatively charged at ambient pH were well removed. Activated carbon, bothinpowderedandgranularforms,waseffectiveforcontaminantadsorption. Carbontype,contacttime,anddoseorregenerationareinuentialparametersin removal efcacy by activated carbon. Although not discussed in this chapter, tight membrane ltration (reverse osmosis and nanoltration) was more effective than loose membrane ltration (ultraltration and microltration). No single treatment process was capable of removing all contaminants consistently to below the analyti - cal method reporting limit. Moreover, each treatment process provided advantages and disadvantages that will be discussed in this chapter. A multibarrier approach wouldprovidethemostcomprehensiveremovalstrategyforthetreatmentoforganic contaminants. 11.2 BACKGROUND In 1965, Stumm-Zollinger and Fair of Harvard University published the rst known report indicating that steroid hormones are not completely eliminated by wastewater treatment. 1 In an article published in 1970, Tabak and Bunch investigated the fate of human hormones during wastewater treatment and stated “since they (hormones) are physiologically active in very small amounts, it is important to determine to what extent the steroids are biodegraded.” 2 As early as the 1940s, scientists were aware that certain chemicals had the ability to mimic endogenous estrogens and andro- gens. 3,4 In 1977 researchers from the University of Kansas published the rst known reportspecicallyaddressingthedischargeofpharmaceuticalsfromawastewater treatment plant. 5 Despitetheseearlyndings,theissueofsteroidsandpharmaceu- ticals in wastewater outfalls did not gain signicant attention until the 1990s, when the occurrence of natural and synthetic steroid hormones in wastewater was linked toreproductiveimpactsinshlivingdownstreamofoutfalls. 6–8 Since the initial link between trace contaminants (sub-µg/L) in wastewater efu- entsandecologicalimpactsinreceivingwaters,manystudieshavefocusedonthe occurrence of these contaminants. 9–17 As a result, pharmaceuticals and steroid hor- moneshavebeendetectedinmanywaterbodiesaroundtheworld. 16,18,19 One major © 2008 by Taylor & Francis Group, LLC Removal of Endocrine Disruptors and Pharmaceuticals 231 contributor of such widespread contamination is municipal wastewater discharge, whichimpactssurfacewaterqualitybycontaminatingreceivingwaterbodieswith chemicals not completely removed by current wastewater treatment processes. Indi - rect potable water reuse, either planned or unplanned, can occur when wastewater treatment plant discharge comprises a signicant portion of the receiving stream’s totalow.Insomecases,efuent-dominatedsurfacewatersareusedassource watersfordrinkingwatertreatmentfacilities.Globalwatersustainabilitydepends in part upon effective reuse of water. In particular the reuse of municipal wastewater is critical for irrigation and augmentation of potable water supplies. However, public perception and concern regarding trace hormones and pharmaceuticals has gener - ate dresistancetoreuseprojects.Itisnecessarytoobtainaccurateinformationon the elimination of these contaminants from wastewater, the impact of wastewater dischargeonsurfacewaterorgroundwaterdrinkingwatersupplies,andtheremoval efciencyoftheremainingcontaminantsbyconventionalandadvanceddrinking water treatment processes. Asignicantnumberofarticleshaveinvestigatedthefateoftracehormonesand pharmaceuticals through water treatment processes. 13,20–33 The ability of a particular treatment process to remove organic contaminants depends mostly on the structure andconcentrationofthecontaminant.Inaddition,theoperationalparametersof the process (e.g., oxidant dose and contact time) will also determine the degree of attenuation of a particular contaminant. Tixier et al. studied the concentration variation of six pharmaceuticals in waste - w at er efuent and river waters. 34 The concentration proles of these contaminants in thewatercolumnofalakeinSwitzerlandweremeasuredover3months.Phototrans- f o rmation, adsorption, and biodegradation were identied as the main elimination processes for these contaminants in the lake water. Loraine and Pettigrove reported the occurrence of pharmaceuticals and personal-care products in raw drinking water at four water treatment plants impacted by sewage treatment plant efuent. 35 Some compounds were detected in nished drinking water, demonstrating that the treat- m e ntprocessesemployedwerenotcapableofcompleteremovalofalltracecon- t a minants. The concentrations in raw water showed high seasonal variations during lowandhighowconditionsinoneofitstwosourcewaters.Temperaturechange can also result in seasonal variation of pharmaceuticals, as observed in Finland at a drinking water plant that was impacted by wastewater. 36 The treatment efciency of pharmaceuticals was evaluated in a few full-scale treatment facilities. Results obtained from one with two-stage coagulation, followed by granular activated carbon (GAC) ltration and chlorine disinfection, have con - rmedpreviousndingsfromlaboratoryinvestigations, 36 where pharmaceuticals werepoorlyremovedbycoagulation,whileGACwasveryefcientinremoving these contaminants. 25,32,37 Anotherteaminvestigatedaconventionalfull-scaledrink- ing water treatment plant, consisting of coagulation, ltration, and disinfection for the treatment efciency of organic contaminants. Pharmaceuticals and other waste - wat er-related organic contaminants were monitored during low ow conditions. 38 Fortyofthemonitoredcompoundsweredetectedinraworsourcewaterandseveral were detected in nished water, suggesting some contaminants were persistent and demonstrated the inefciency of commonly employed treatment processes. © 2008 by Taylor & Francis Group, LLC 232 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems To date, the number and type of organic contaminants investigated are still lim- ited considering the large pool of undetected chemicals. The sparse information on the occurrence and removal efciency of many yet-to-be investigated organic con- ta minants stimulated the work presented in this chapter, which was performed at both bench and pilot scales, and subsequently evaluated by full-scale investigations. 11.3 SELECTION OF TARGET COMPOUNDS Target compounds were selected from various classications of organic contami- nants. Classes included pharmaceuticals, hormones, personal-care products, sus- pected endocrine disruptors, and other model compounds. Pharmaceuticals were selected to encompass several therapeutic classications including: antibiotics, analgesics, birth control, psychoactive drugs, and cholesterol-lowering medications. Target compounds included seven hormones that represent both estrogens and andro - ge ns.Severalsuspectedendocrinedisruptors,includingatrazineandtriclosan,were also included. These compounds present a diverse group of chemical structures, such that the fate of future contaminants can be predicted based upon their structure. Four primarycriteriawereconsideredduringtheselectionprocess. Therstcriterionwaslikelihoodofoccurrenceintheenvironment.Previous publications from peer-reviewed journals and government reports were considered. Pharmaceuticals have been identied in surface waters, groundwaters, and wastewa - te rs in the United States, Europe, Asia, and other continents around the world. 35,39–44 Among these, the nationwide occurrence surveys conducted byU.S.G eologicalSur- vey(USGS)draw themostattention,forwhichpharmaceuticalscompriseasig- nicant portion of the contaminants investigated. 16,45 These reports were considered during the initial selection process to warrant the inclusion (or rejection) of various candidate contaminants. Thesecondcriterionwastoxicologicalrelevanceandpublicinterest.Pharma- ce uticals were selected based on concerns over long-term, low-dose exposure, which have been implicated as a possibility in increased antibiotic resistance and allergic reactions. 46–48 Steroids were considered because they are biologically active at low concentrationsandfrequentlyincludedinmanystudiesduetoseriousconcernof theirestrogeniceffecttoaquaticspecies. Thethirdcriterionwasstructuraldiversityandtreatability.Thisisreectedby thewiderangeofmolecularweight(MW),watersolubility(S),octanol/waterpar - ti tioningcoefcient(logK ow ), and acidic/basic properties (Table 11.1). The removal of each compound is intrinsically linked to its chemical structure and the particu- la r treatment process. For instance, phenolic compounds are amenable to oxidation treatment and hydrophobic compounds can readily adsorb to GAC. An herbicide, a pesticide, two fragrances, and a ame retardant were included to increase structural diversity. This breadth of chemical structure ensures a reasonable span of treatability foranobjectiveevaluationofeachunitprocess. The fourth and nal criterion was analytical capability. The limiting factors are the availability of analytical standards and method performance for specic compounds with analytical equipment available. Compounds for which puried standards were not commercially available were not included. Signicant quanti - ti es of compounds were required in order to conduct the spiked batch and dynamic © 2008 by Taylor & Francis Group, LLC Removal of Endocrine Disruptors and Pharmaceuticals 233 treatmentstudies.Somecompoundscouldnotbeconsideredduetoalackof,orthe costof,availablestandards.Sinceallcompoundswereintendedtobeextractedbya single solid-phase extraction (SPE) method, some analytes could not be accommo - dated with the operational parameters considered. 49 TABLE 11.1 Physicochemical Properties of Selected Pharmaceuticals* Compounds Classes CAS MW S (mg/L) Log K OW pKa Acetaminophen Analgesic 103-90-2 151.2 1.40E+4 0.46 9.38 Androstenedione Hormone 63-05-8 286.4 57.8 2.75 na Atrazine Herbicide 1912-24-9 215.7 34.7 2.61 1.7 Caffeine Psychoactive 58-08-2 194.2 2.16E+4 –0.07 10.4 Carbamazepine Psychoactive 298-46-4 236.3 18 50 2.45 13.9 51 DEET** Insect repellant 134-62-3 191.3 9.9 52 2.18 0.7 (est) Diazepam Psychoactive 439-14-5 284.7 50 2.82 3.4 Diclofenac Analgesic 15307-86-5 296.2 2.37 4.51 4.15 Dilantin Psychoactive 57-41-0 252.3 32 2.47 8.33 Erythromycin Antimicrobial 114-07-8 733.9 1.44 (est) 3.06 8.88 Estriol Hormone 50-27-1 288.4 441 (est) 2.45 9.85 (est) Estradiol Hormone 50-28-2 272.4 3.6 4.01 10.4 53 Estrone Hormone 53-16-7 270.4 30 3.13 10.4 53 Ethynyl estradiol Hormone 57-63-6 296.4 11.3 3.67 10.4 54 Fluoxetine Psychoactive 54910-89-3 309.3 60.3 (est) 4.05 10.3 (est) Galaxolide Fragrance 1222-05-5 258.4 1.75 55 5.9 55 na Gembrozil Antilipidemic 25812-30-0 250.3 19 (est) 4.33 (est) 4.42 Hydrocodone Analgesic 125-29-1 299.4 6870 (est) 2.16 (est) 8.35 (est) Ibuprofen Analgesic 15687-27-1 206.3 21 3.97 4.91 Iopromide x-ray contrast agent 73334-07-3 791.1 23.8 (est) –2.05 10.2 (est) Meprobamate Psychoactive 57-53-4 218.3 4700 0.7 10.9 (est) Metolachlor Pesticide 51218-45-2 283.8 530 3.13 na Musk ketone Fragrance 81-14-1 294.3 0.46, 56 1.9 57 4.3 56 na Naproxen Analgesic 22204-53-1 230.3 15.9 3.18 4.15 Pentoxifylline Vasodilator 6493-05-6 278.3 7.70E+4 0.29 1.49 (est) Progesterone Hormone 57-83-0 314.5 8.81 3.87 na Sulfamethoxazole Antimicrobial 723-46-6 253.3 610 0.89 5.5 58 TCEP*** Flame retardant 115-96-8 285.5 7000 1.44 na Testosterone Hormone 58-22-0 288.4 23.4 3.32 na Triclosan Antimicrobial 3380-34-5 289.5 10 4.76 7.9 59 Trimethoprim Antimicrobial 738-70-5 290.3 400 0.91 7.12 *Unless indicated, all are experimental values from Environmental Science Database SRC PhysProp ** Chemical name: N,N-diethyl-meta-toluamide *** Chemical name: Tri(chloroethyl)phosphate © 2008 by Taylor & Francis Group, LLC 234 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems Table 11.1 provides the list of target compounds discussed in this chapter follow- ing the aforementioned selection criteria. Also summarized in this table are the com- pound classication and molecular properties pertinent to water treatment processes. These particular properties provide information on molecular size, hydrophobicity, and molecular charge under ambient pH. 11.4 ANALYTICAL METHODS One-liter samples were collected in silanized amber glass bottles for bench-, pilot-, andfull-scaleinvestigations.SampleswerepreservedbyadjustingthepHto2for microbialactivitycontrolandascorbicacidwasusedtoquenchdisinfectantresid- ual. 17 ThepHadjustmentwasfoundimportanttopreventthebiodegradationofcer- tain steroids and the pharmaceuticals trimethoprim, acetaminophen, and uoxetine. 17 Grab samples were taken by personnel from each utility with general water qualities monitoredsimultaneously.Foreachplant,atleastonesitewasselectedfordupli- ca tesamples(usuallytherawwater)forqualitycontrol.Additionally,travelblanks, laboratoryblanks,andmatrixspikeswerepreparedwitheachsamplingevent.The sampleswereshippedbacktothelaboratoryinanice-packedcoolerbyovernight express shipping. Allsampleswereextractedinbatchesofsixsamplesusingautomated-SPE (ASPE) utilizing 500-mg hydrophilic-lipophilic balance (HLB) cartridges from Waters Corp. (Millford, Massachusetts). Cartridges were sequentially precondi - ti oned by methyl tertbutyl ether (MTBE),met hanol, and reagent water. The absorbed analytes were then eluted with 10/90 (v/v) methanol/MTBE solution and pure metha- nol,followedbyconcentrationtoavolumeof1mLwithnitrogen. Pharmaceuticals, hormones, and atrazine were analyzed by liquid chromatogra- phy with tandem mass spectrometric detection (LC-MS/MS) using electrospray ion- ization (ESI) in both positive and negative modes and atmospheric pressure chemical ionization (APCI) in positive mode following a method published previously. 17 The remaining chemicals were analyzed by gas chromatography with tandem mass spectrometric detection (GC-MS/MS). 49 The same SPE procedure was used; however,aportionoftheresultingextractwasremovedandreextractedusingdichlo- romethaneinordertoremovecompoundsthatinterferewithGC-MS/MSanalysis. 49 Method performance in terms of instrument detection limits (IDLs) and spiked recoveries remain unchanged from previously published work. 17,49 The spike recov- eries of most target compounds were generally above 70% for LC-MS/MS and above 60% for GC-MS/MS analysis with the exception of acetaminophen and galaxolide (41% and 30%, respectively). A conservative method reporting limit (MRL) of 1 ng/LformostLC-MS/MScompoundsand10ng/LforGC-MS/MScompoundswas established for this method. While concentrations are reported without adjustment for the recovery, all treatment data are shown as percent removal through a treatment process. The percent removal is not impacted by analytical recovery, since the recov - e r ywasconstantinboththe“raw”and“nished”waterofeachprocess. © 2008 by Taylor & Francis Group, LLC Removal of Endocrine Disruptors and Pharmaceuticals 235 11.5 BENCH-SCALE EVALUATIONS 11.5.1 B ENCH-SCALE EXPERIMENTAL PROCEDURES Evaluation of contaminant oxidation by chlorine, chloramine, ozone, and UV, and adsorptionbyGACandMIEXwasperformedusingColoradoRiverwater(CRW) spikedwith100to300ng/Lofeachofthetargetcompounds.Thespikingconcentra- ti on was selected such that removal to the MRL would provide approximately 2-log removal(99%).ExperimentalconditionsforevaluationaresummarizedinTable11.2. T heCRWquality,assampledfromtheSouthernNevadaWaterAuthorityintakesin LakeMead,isrelativelystablewithaveragevaluesprovidedinTable1 1.3. Ch lorination experiments were performed using liquid sodium hypochlorite (NaOCl, Fisher Scientic,Pittsburgh,P ennsylvania).Stock solutionsofchlorinewere initiallypreparedindeionized(DI)waterat1200mg/L.Chlorinewasdoseddirectly into 1-L bottles containing the source water. Chlorine doses were determined based uponthechlorinedemandinordertoachievearesidualgoalofapproximately0.5 mg/L after 24 hours. Free chlorine residuals were measured by the N,N-diethyl-p- phehylenediamine (DPD) Method using a Hach DR4000 spectrophotometer (U.S. Environmental Protecton Agency [USEPA]-approved Hach Method #8021, Hach Company, Loveland, Colorado). Experiments were conducted at ambient water pH and at a suppressed pH of 5.5. After the 24-hour contact time, residual chlorine was quenched with 50 mg/L of ascorbic acid. Analytical surrogates sensitive to chlo - ri newereaddedjustpriortosolid-phaseextraction;therefore,analyticalrecovery of these surrogates provided denitive information on whether or not the chlorine residual was quenched. Chloramineexperimentswereperformedbyrstaddingammoniatoa1-Lsam - pl e of raw water followed by sodium hypochlorite addition. Stock solutions of each chemical were created from 29% ammonium hydroxide (J.T. Baker, Phillipsburg, N ewJersey)an d5%s odium hypochlorite (NaOCl, Fisher Scientic). A chlorine: ammoniaratioof4:1wastargetedbecausethisiscommonlyusedindrinkingwater treatment. This sequence of chemical addition was selected over preformed mono- ch loramine solution to closely simulate actual water treatment plant conditions. The TABLE 11.2 Experimental Matrix for Bench-Scale Studies Tests Dosage Contact Time Ozone 2.5 mg/L 5 min Free chlorine 3, 3.5 mg/L 24 hr UV 40 mJ/Cm 2 Chloramine 2, 3 mg/L 24 hr MIEX 5, 15, 20 mL/L 10 min GAC n/a 7.6 min EBCT* * EBCT: Empty bed contact time. © 2008 by Taylor & Francis Group, LLC 236 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems experiments were conducted at room temperatures (approximately 20°C) at ambient pH.Thechloramineresidualwasquenchedwithascorbicacidusingaratioof20:1 ascorbic acid:chlorine. Ozone experiments were conducted by injecting a high concentration of dis - so lvedozoneintoa1-Lsamplebottlecontainingthesourcewater.Dissolvedozone stocksolutionwaspreparedbydissolvingahighconcentrationofgaseousozoneinto DI water at 2°C. Dissolved ozone stock solution concentrations and dissolved ozone residuals were measured spectrophotometrically using the indigo method (Standard Methods 4500-O 3 ). The ozone dose was determined using an ozone demand/decay curvegeneratedfortheCRW. 30 MIEXisaprocessthatutilizesmagneticpolymermicrospheresasanion exchange resin. The resin is composed of a polymer and inorganic magnetic mate- ri als such as Fe 3 O 4 ,Fe 2 O 3 ,nickel,andcobaltsothattheresinexhibitsthechar- acteristics of both ionic exchange and magnetism in order to achieve rapid and improvedseparationforregenerationandrecycle.MIEXresin(OricaWatercare, Inc.,Watkins,Colorado)fromanon-sitepilotplantprovidedtheresinforthejar testing. Gravity separation of the resin is very efcient because of the “magneti - ca lly” enhanced agglomeration of individual resin beads that yields resin settling againsttherapidlyrisingwaterinthesettler.SincetheMIEXresinusedforbench- scaletestingwascycledseveraltimesthroughthepilotsystem,thebindingcapacity waslikelydecreased,andwasmorerepresentativeofaresinthatwouldbeinservice TABLE 11.3 Average Water Quality of Colorado River Water Water Quality Parameter Average Minimum Maximum pH 7.79 7.68 7.99 Temperature ( o C) 21 20 22 Turbidity (NTU) 0.73 0.35 1.5 UV254 (1/cm) 0.029 0.025 0.037 Alkalinity (mg/L) 133 131 134 Bromide (mg/L) 0.08 0.05* 0.10 Chloride (mg/L) 84 75 94 Hardness (mg/L) 288 260 310 Sulfate (mg/L) 246 230 250 SUVA 1.2 — — TDS (mg/L) 619 602 642 TOC (mg/L) 3.23 2.9 3.4 * Below method reporting level. © 2008 by Taylor & Francis Group, LLC Removal of Endocrine Disruptors and Pharmaceuticals 237 ascomparedtovirginmaterial.MIEXconcentrationsof5,15,and20mL/Lwere evaluated with a 10-minute contact time. These experiments mimicked conditions used during previous pilot testing. 60 Bench-scale testing was conducted using rapid small-scale column tests (RSSCTs) to predict GAC performance. A detailed description of these tests was published previously. 31 The RSSCT design used constant diffusivity similitude, wheretheratioofemptybedcontacttimeisproportionaltothesquareoftheratioof the grain diameters. 61 Constant diffusivity similitude was selected because Critten- denandothershavefoundthistobemoreappropriatethanproportionaldiffusivity for“smaller”molecularweightdiscretemoleculesthatdonothaveahighcharge. 61 Proportionaldiffusivityhasbeenfoundmostappropriatefornaturalorganicmat- te rwithanaveragemolecularweightof1000Daltonsorhigher,whichalsohasa considerable charge, and for highly charged inorganic species such as perchlorate. 62 Moreover,constantdiffusivityisthemore“conservative”similitudetouse(i.e.,if RSSCTexhibitsthatanorganicmoleculewillberemovedwithinacertainbedlife whenusingconstantdiffusivity,thenthepredictedbedlifeatfullscalewillbethe same or longer). Tests were performed with the lignite-based GAC Hydrodarco 4000 (HD4000)manufacturedbyNorit.Inaccordancewithconstantdiffusivitysimili - tudeforthetargetcompounds,acolumnwith0.307-cm 3 empty bed volume was utilized with the test carbons crushed and wet-sieved to 75 to 90-μm particle size (170 × 200 US mesh). With this design, RSSCTs simulated a full-scale column that operatesata7.6-minuteemptybedcontacttime(EBCT).CRWwasspikedwith 100to200ng/Lofthetargetcompounds.Thetestcolumnwasmaintainedatroom temperature between 20 and 25ºC. UV bench-scale experiments were conducted using a collimated beam system equipped with medium pressure lamp (Calgon Carbon Corporation, Pittsburgh, Pennsylvania). Aliquots of spiked CRW (500 mL) were irradiated in a 600-mL glass beakeronamagneticstirplatecenteredwithrespecttothelightbeam.Sampleswere irradiated for predetermined periods of time corresponding to selected UV uences (UV dose). Irradiance measurements were collected with a 1700 International Light Research Radiometer with SED40 detector, calibrated at each wavelength within a200-to340-nmrange.UVuenceswerecalculatedusingaspreadsheetbased on the incident irradiance, sample geometry, and water absorption spectrum, as described elsewhere. 63 During advanced oxidation experiments, hydrogen peroxide wasadded1minutepriortoexposure,and r esiduals were quenched with 0.2 mg/L bovine catalase. 11.5.2 RESULTS FROM BENCH-SCALE STUDIES ThecomparisonsfortheremovaloftargetanalytesbyUV,freechlorine,andozone are presented in Figure 11.1 t hroughFigure 11 .5, according to compound classi- cations.Overall,UVisnotabletoprovidesignicantremovaltomosttargetana- ly tesunderacommondisinfectiondoseof40mJ/cm 2 . Free chlorine disinfection is signicantly more efcient than UV disinfection for contaminant removal, while ozone disinfection can oxidize nearly all target compounds investigated. It should be © 2008 by Taylor & Francis Group, LLC 238 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems notedthatnoprocesswascapableofremovingalltargetcompoundstolessthanthe method reporting limits. TwoprincipalmechanismsforcontaminantremovalbyUVirradiationarepos- sible.First,UVcandirectlycleavebondsinorganicmoleculesbydirectphotolysis ofthetargetmolecule.Second,UVreactswithinorganicconstituentsinwaterto form highly reactive intermediates, with the formation of hydroxyl radicals (HO • ) 0 20406080100 Trimethoprim Triclosan Sulfamethoxazole Erythromycin % Removal UV 40 mJ Ozone 2.5 mg/LChlorine 3.5 mg/L FIGURE 11.2 Removal of antimicrobials by UV, chlorine, and ozone. 0 20406080100 Ethynylestradiol Estrone Estriol Estradiol Progesterone Androstenedione Testosterone % Removal UV 40 mJ Ozone 2.5 mg/LChlorine 3.5 mg/L FIGURE 11.1 Removal of hormones by UV, chlorine, and ozone. © 2008 by Taylor & Francis Group, LLC [...]... detected at the greatest concentration in drinking waters Atrazine was detected in 85% of raw waters and 75% of finished waters, with maximum concentrations of 571 and 430 ng/L, respectively Drinking water treatment processes evaluated here were largely ineffective for the removal of atrazine, with the exception of activated carbon The antibiotic sulfamethoxazole occurred in 85% of raw water samples... relatively low and explains the minimal removal observed at disinfection dosages This finding is consistent with a study conducted by Rosenfeldt and Linden who examined the degradation of 17 -ethynyl estradiol and 17 -estradiol © 2008 by Taylor & Francis Group, LLC 240 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems UV 40 mJ Chlorine 3.5 mg/L Ozone 2.5 mg/L DEET Atrazine Metolachlor... Impact of scaling at an ozone dose of 2.5 mg/L obtained with the 23-L/min © 2008 by Taylor & Francis Group, LLC 248 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems the only target compounds with less than 50% reduction at the minimum UV-AOP dose applied (Table 11. 4) A constant UV dose of approximately 370 mJ/cm2 was applied with hydrogen peroxide doses of 5.8 and 7.6 mg/L Interestingly,... Removal of Endocrine Disruptors and Pharmaceuticals 249 11. 7 FULL-SCALE EVALUATIONS Samples of raw and finished drinking water were collected from 20 drinking water treatment plants from geographically diverse locations across the United States Treatment plants were selected based upon known wastewater influence in the source water Therefore, these utilities have the highest potential to contain EDC/PPCP... Kow values are for the neutral form of the molecules For these species, the octanol water distribution coefficient (Dow) should be more appropriate to represent their hydrophobicity and relate to their removal tendency Dow is the ratio of the sum of the concentrations of all species of the compound in octanol to the sum of the concentrations of all species of the compound in water, and its value highly... was detected in 30% of the raw water samples at low concentrations ranging from 1 to 30 ng/L, while it was detected in only one finished water sample at 45 ng/L The facility that contained the highest level of triclosan in the raw water also contained the only detection of triclosan in the finished water This utility was also the only location with sulfamethoxazole detected in the finished water Both... stronger oxidizing and substituting agent than OCl-.69 The oxidative power of aqueous chlorine highly depends on pH Results summarized in Figure 11. 6 confirmed this point The removal capability of free chlorine almost doubled when pH decreased from 8.2 to 5.5 Chloramine in the form of monochloramine is commonly used for the distribution system in drinking water supplies to maintain chlorine residual... detected in one finished drinking water sample This facility had 40 ng/L of sulfamethoxazole in the raw water and 20 ng/L in the finished water, thus 50% of this antibiotic was removed through the plant The poor removal at this facility can be explained by the use of chloramines for primary disinfection, which was shown to be much less reactive with sulfamethoxazole than free chlorine (Figure 11. 6) The pharmaceuticals. .. detected in 90% of raw water samples with maximum concentrations of 39 and 13 ng/L, respectively In finished drinking water, carbamazepine and dilantin were less frequently detected (55 and 70%, respectively) with maximum concentrations of 5.7 and 6.7 ng/L, respectively These data show that drinking water treatment will significantly reduce the concentrations of these pharmaceuticals Atrazine was detected... Summarily, these results show that removal of trace contaminants in a full-scale drinking water treatment plant will largely be a function of the primary disinfectant, the secondary disinfectant, and contact time Carbon adsorption and membranes are also viable removal tools, but are far less common in drinking water treatment applications 11. 8 CONCLUSION The use of oxidants for the attenuation of trace . gener - ate dresistancetoreuseprojects.Itisnecessarytoobtainaccurateinformationon the elimination of these contaminants from wastewater, the impact of wastewater dischargeonsurfacewaterorgroundwaterdrinkingwatersupplies,andtheremoval efciencyoftheremainingcontaminantsbyconventionalandadvanceddrinking water. identied as the main elimination processes for these contaminants in the lake water. Loraine and Pettigrove reported the occurrence of pharmaceuticals and personal-care products in raw drinking water at. contaminants. 25,32,37 Anotherteaminvestigatedaconventionalfull-scaledrink- ing water treatment plant, consisting of coagulation, ltration, and disinfection for the treatment efciency of organic contaminants. Pharmaceuticals and other waste - wat er-related