Potential of Advanced Oxidation Potential of Advanced Oxidation Processes (AOP) for Processes (AOP) for

Simultaneous Disinfection and Simultaneous Disinfection and Polishing of Drinking WaterPolishing of Drinking Water

ASCE New Orleans Branch – LA Civil Engineering Conference & Show, Kenner, LA

September 13, 2002

Jennifer E. HollandJennifer E. HollandTulane University, New Orleans, LATulane University, New Orleans, LA

Glen R. Boyd, Ph.D., PEGlen R. Boyd, Ph.D., PEDept. of Civil & Environmental EngineeringDept. of Civil & Environmental Engineering

Robert S. Reimers, Ph.D. FAICRobert S. Reimers, Ph.D. FAICAndrew J. Andrew J. EnglandeEnglande, Ph.D., P.E., Ph.D., P.E.

Dept. of Environmental Health SciencesDept. of Environmental Health Sciences

IntroductionIntroductionScope of PresentationScope of Presentation

•• Potential application of advanced oxidation processes Potential application of advanced oxidation processes (AOP) for drinking water treatment (AOP) for drinking water treatment

Specific ObjectivesSpecific Objectives

1.1. Overview of conventional treatment for disinfection and Overview of conventional treatment for disinfection and micropollutantsmicropollutants

2.2. EDCsEDCs/PPCPs as emerging micropollutants/PPCPs as emerging micropollutants3.3. Potential applications of AOP in meeting conventional Potential applications of AOP in meeting conventional

treatment goals for micropollutantstreatment goals for micropollutants4.4. Ongoing research at Tulane UniversityOngoing research at Tulane University

OutlineOutlineBackgroundBackground

•• MicropollutantsMicropollutants -- EDC/PPCPsEDC/PPCPs•• Conventional WTConventional WT

Ongoing Research at TulaneOngoing Research at Tulane•• Occurrence of EDC/PPCP in SE Louisiana Occurrence of EDC/PPCP in SE Louisiana •• Advanced Oxidation Processes (Advanced Oxidation Processes (AOPsAOPs))

MethodsMethods

Preliminary ConclusionsPreliminary Conclusions

Next StepsNext Steps

Background Background -- Contaminated Contaminated Drinking Water SourcesDrinking Water Sources

MicropollutantsMicropollutants

•• Pesticides, fertilizers, industrial Pesticides, fertilizers, industrial solventssolvents

Toxics, carcinogensToxics, carcinogens

•• Typical concentrations in Miss River Typical concentrations in Miss River Water Water

AtrazineAtrazine = 1 ppb (Source: = 1 ppb (Source: GoolsbyGoolsbyand Pereira, USGS)and Pereira, USGS)

•• Seasonal characteristics (e.g., Seasonal characteristics (e.g., storm events) storm events)

AtrazineAtrazine = 7 ppb = 7 ppb MCL = 3 ppb MCL = 3 ppb (Source: (Source: GoolsbyGoolsbyand Pereira, USGS)and Pereira, USGS)

•• Emerging lowEmerging low--level contaminants level contaminants Endocrine disrupting chemicals (Endocrine disrupting chemicals (EDCsEDCs))Pharmaceuticals and personal care Pharmaceuticals and personal care products (PPCPs)

Barber et al., www.usgs.gov

products (PPCPs)

BackgroundBackground----EDCsEDCs

Chemicals which Chemicals which affect the endocrine affect the endocrine systemsystem

Trussel, R. R. 2001, JAWWA 93(2):58-65

Background Background -- MicropollutantsMicropollutantsWhy are low levels of EDCs a cause for concern?

DOSE RESPONSE

Dose Calculation

Theoretical Concentration in Drinking Water Source

= 100 ppt (ng/L)

70 kg Adult drinks 2 L of water per day

Dose = (100 * 2)/70,000

= 0.003 ng/gVom Saal et al., 1997

http://www.safewater.org/conferences/proceedings/lawrence.htm

BackgroundBackground----MicropollutantsMicropollutantsSynergistic effect of mixture of Synergistic effect of mixture of EDCsEDCs? ? ----> 0.003 ng/g dose?> 0.003 ng/g dose?

Background Background –– Conventional WTConventional WT

J. Lawrence “Drinking Water Treatment Present and Future Developments” http://www.safewater.org/conferences/proceedings/lawrence.htm

Some PPCPs/EDCsare soluble and refractory-->

not removed by conventional water treatment

Background Background –– Chlorine in Chlorine in Conventional WTConventional WT

Chlorine does kill harmful Chlorine does kill harmful microorganismsmicroorganisms

Fecal Fecal coliformcoliformE. coliE. coliEntercocciEntercocci

Does not kill protozoan Does not kill protozoan oocystsoocysts

CryptosporidiumCryptosporidiumGiardiaGiardia

BackgroundBackground----Chlorine for Chlorine for Conventional WTConventional WT

Chlorine combines with natural organic Chlorine combines with natural organic matter (NOM) to form disinfection matter (NOM) to form disinfection byproducts (byproducts (DBPsDBPs))

TrihalomethanesTrihalomethanes ((THMsTHMs))

Effects of ClEffects of Cl22 on organic micropollutants on organic micropollutants (EDC/PPCPs)? (EDC/PPCPs)?

Possible formation of chlorinated metabolitesPossible formation of chlorinated metabolitesNeed more researchNeed more research

Background Background –– Conventional WTConventional WTGranular Activated Carbon (GAC)

May be used to remove organicsMay be used to remove organicsAdsorbs organic chemicalsAdsorbs organic chemicalsDependent on solubility of chemicalDependent on solubility of chemical

•• Many drugs designed to be highly water soluble (check Many drugs designed to be highly water soluble (check KKowow))

Can be used at water treatment plantCan be used at water treatment plant•• Highly expensiveHighly expensive•• Must be regeneratedMust be regenerated

Also implemented at point of use (Brita, Also implemented at point of use (Brita, PurPur))

Background Background -- AOPsAOPsAdvanced Oxidation Processes Advanced Oxidation Processes ---- generate free generate free radicals (OHradicals (OH••, O, O33

••, OH, OH22••))

Hydroxyl radicals indiscriminately oxidize Hydroxyl radicals indiscriminately oxidize organic matterorganic matter

Recalcitrant organicsRecalcitrant organicsCell walls of protozoan Cell walls of protozoan oocystsoocystsProcess combines disinfection/oxidation into one stepProcess combines disinfection/oxidation into one step

May be more effective than ClMay be more effective than Cl22 and GACand GAC

Background Background -- AOPsAOPs

1.71.7Chlorate (ClOChlorate (ClO44))

1.71.7Chlorite (ClOChlorite (ClO33))

1.71.7Chlorine Dioxide (ClOChlorine Dioxide (ClO22) )

1.61.6Chlorine (ClChlorine (Cl22/OCl/OCl-))

1.81.8Hydrogen Peroxide (HHydrogen Peroxide (H22OO22))

2.12.1Ozone (OOzone (O33))

2.62.6Hydroxyl Radical (OHHydroxyl Radical (OH··))

Oxidizing Power (V)Oxidizing Power (V)OxidantOxidant

Research at Tulane Research at Tulane ––EDC/PPCPs in Source WatersEDC/PPCPs in Source Waters

Target Compounds and Detection LimitsTarget Compounds and Detection Limits

Target compounds and Method Detection Limits (MDL)

Target Compound

IDL [ng/L]

Average % Recov.

% RSD

Compl of Deriv (%)

MDL* [ng/L]

Clofibric acid 3 60.8 12.6 100 0.6Estrone 3 91.9 5.1 100 0.517β-Estradiol 1 90.5 9.1 100 0.1Ibuprofen 13 47.1 26.9 0 3.5Naproxen 3 87.9 2.8 0 0.4Acetaminophen 45 N.D. N.D. 100 N.D.Bisphenol-A 0.6 99.7 3.5 100 0.1Chlorophene 0.6 71.7 5.9 100 0.1Triclosan 1 53.8 24 100 0.2

Research at Tulane Research at Tulane ––EDC/PPCPsEDC/PPCPs

MonitoringMonitoringLake Lake PontchartrainPontchartrain

&&Mississippi River

Sampling Site

date 9/14/01 9/24/01 9/14/01 9/24/01Target Compound ng/L ng/L ng/L ng/LNaproxen 107 22 37 39Bisphenol-A-d14* 13.6% 13.9% 68.0% 75.0%Estrone-d4* 52.6% 28.9% 103.4% 119.4%Acetaminophen-d4* 1.1% 1.2% N.D. N.D.

LakePontchartrain

MississippiRiver

Mississippi River

Research at Tulane Research at Tulane –– AOPsAOPsBench Scale Experiments

Comparison of four different Comparison of four different AOPsAOPs::

1.1. PeroxonePeroxone•• OO33 + H+ H22OO22 OHOH••

2.2. Ozone plus UVOzone plus UV•• OO33 + UV + UV OHOH••

3.3. Hydrogen Peroxide plus UVHydrogen Peroxide plus UV•• HH22OO22 + UV + UV OHOH••

4.4. Mixed OxidantsMixed Oxidants•• High energy vapor including OHHigh energy vapor including OH••

Research at Tulane Research at Tulane -- AOPsAOPs

oxygenfeed gas

(P, Q)

chiller (T)

ozone generator

(P, Q)ozone

monitor

stabilization tank (T, P)

ozone monitor

254 nm UV lamp

Mixed oxidant generator

sampling valve

contact chamber

water recirculation

diffuser

3-way valve

ozone destruction chamber

Research at Tulane Research at Tulane -- AOPsAOPsPreliminary Preliminary

ConclusionsConclusionsMixed oxidants have a slightly Mixed oxidants have a slightly greater oxidizing power than ozone greater oxidizing power than ozone alonealone

Mixed oxidants are an effective Mixed oxidants are an effective disinfectantdisinfectant

Mixed oxidants were more effective Mixed oxidants were more effective in the oxidation of micropollutants in the oxidation of micropollutants (MTBE) than ozone alone(MTBE) than ozone alone---- more more research neededresearch needed

MethodsMethodsUse Use AOPsAOPs bench scale apparatus to investigate removal of EDC bench scale apparatus to investigate removal of EDC and PPCP micropollutantsand PPCP micropollutants

•• NaproxynNaproxyn•• 1717ββ--EstradiolEstradiol•• BisphenolBisphenol--AA

Spike DI water samplesSpike DI water samples0 to 10 0 to 10 µµg/Lg/L

Spike Mississippi River samples Spike Mississippi River samples 10 to 100 ng/L10 to 100 ng/L

Isolate using SPE, Isolate using SPE, derivatizederivatize using BSTFA, analyze using GC/MSusing BSTFA, analyze using GC/MS

Methods Methods -- NaproxynNaproxyn

AntiAnti--inflammatory inflammatory prescription drugprescription drug

No known endocrine No known endocrine disrupting effectsdisrupting effects

Log Log KKowow ~ 3.10~ 3.10

Methods Methods -- 1717ββ--EstradiolEstradiol

HormoneHormone

Endocrine DisruptorEndocrine Disruptor

Log Log KKowow = 3.94= 3.94

Methods Methods -- BisphenolBisphenol--AA

Plasticizing agentPlasticizing agent

Suspected endocrine Suspected endocrine disruptordisruptor

Log Log KKowow = 3.32= 3.32

MethodsMethods

Study each compound separately in a DI water matrix

Determine doses of ozone, peroxide, UV light Determine doses of ozone, peroxide, UV light and mixed oxidants required for complete and mixed oxidants required for complete mineralizationmineralization

Compare material and power costs of Compare material and power costs of AOPsAOPs to to ClCl22 and GAC estimated values

Overview of Experiments

Study each compound separately in a DI water matrix

and GAC estimated values

Preliminary ConclusionsPreliminary Conclusions

AOPsAOPs may be a more cost effective means may be a more cost effective means to disinfect and polish potable water to disinfect and polish potable water compared to chlorine and GACcompared to chlorine and GAC

Data from bench scale experiments at Data from bench scale experiments at Tulane University may be used in the Tulane University may be used in the design of a pilot scale AOP system for design of a pilot scale AOP system for New Orleans drinking waterNew Orleans drinking water

Next StepsNext Steps

Complete ongoing AOP experimentsComplete ongoing AOP experiments----optimization of Tulane mixed oxidant processoptimization of Tulane mixed oxidant process

Develop laboratory standards and analytical Develop laboratory standards and analytical procedures for EDC/PPCP procedures for EDC/PPCP micrpollutantsmicrpollutants

Complete AOP experiments for treatment of Complete AOP experiments for treatment of spiked DI and Miss. R. water samplesspiked DI and Miss. R. water samples

Compare results to GAC data

Oct 2002

Dec 2002

Mar 2003

June 2003Compare results to GAC data

AcknowledgementsAcknowledgementsSevern Trent Services, Inc.Severn Trent Services, Inc.

Gordon Austin, Peter Brown, Glenn Gordon Austin, Peter Brown, Glenn SemelSemel --New Orleans Sewerage and Water BoardNew Orleans Sewerage and Water Board

Dr. D. Grimm Dr. D. Grimm -- Coordinated Instrumentation Coordinated Instrumentation Facility, Tulane UniversityFacility, Tulane University

HelgeHelge ReemstmaReemstma, , BingenBingen University, GermanyUniversity, Germany