PNWS AWWA 2008 Annual Conference Vancouver, Washington

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PNWS AWWA 2008 Annual PNWS AWWA 2008 Annual Conference Conference Vancouver, Washington Vancouver, Washington Contaminants of Emerging Contaminants of Emerging Concern in Water and Concern in Water and Wastewater Treatment Wastewater Treatment John Bratby John Bratby Brown and Caldwell Brown and Caldwell

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PNWS AWWA 2008 Annual Conference Vancouver, Washington. Contaminants of Emerging Concern in Water and Wastewater Treatment John Bratby Brown and Caldwell. Contaminants of Emerging Concern in Water and Wastewater Treatment. Nature of CECs Removal mechanisms of CECs - PowerPoint PPT Presentation

Transcript of PNWS AWWA 2008 Annual Conference Vancouver, Washington

Page 1: PNWS AWWA 2008 Annual Conference Vancouver, Washington

PNWS AWWA 2008 Annual ConferencePNWS AWWA 2008 Annual ConferenceVancouver, WashingtonVancouver, Washington

Contaminants of Emerging Concern Contaminants of Emerging Concern in Water and Wastewater Treatmentin Water and Wastewater Treatment

John BratbyJohn Bratby

Brown and CaldwellBrown and Caldwell

Page 2: PNWS AWWA 2008 Annual Conference Vancouver, Washington

Contaminants of Emerging Concern in Contaminants of Emerging Concern in Water and Wastewater TreatmentWater and Wastewater Treatment

Nature of CECsNature of CECs Removal mechanisms of CECsRemoval mechanisms of CECs Removal efficiencies of CECs during Removal efficiencies of CECs during

treatmenttreatment Do membrane bioreactors provide Do membrane bioreactors provide

enhanced removal of CECs?enhanced removal of CECs? Other advanced treatment for higher Other advanced treatment for higher

levels of CEC removallevels of CEC removal

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Recent AP articleRecent AP article ““Mary Buzby -- director of environmental technology for drug Mary Buzby -- director of environmental technology for drug

maker Merck & Co. Inc.: maker Merck & Co. Inc.: "There's no doubt about it, pharmaceuticals "There's no doubt about it, pharmaceuticals are being detected in the environment and there is genuine concern that are being detected in the environment and there is genuine concern that these compounds….could be causing impacts to human health or to these compounds….could be causing impacts to human health or to aquatic organisms.“aquatic organisms.“

Recent laboratory research has found that small amounts of Recent laboratory research has found that small amounts of medication have affected human embryonic kidney cells, medication have affected human embryonic kidney cells, human blood cells and human breast cancer cells. The human blood cells and human breast cancer cells. The cancer cells proliferated too quickly; the kidney cells grew too cancer cells proliferated too quickly; the kidney cells grew too slowly; and the blood cells showed biological activity slowly; and the blood cells showed biological activity associated with inflammation.associated with inflammation.

Some scientists stress … that the documented health Some scientists stress … that the documented health problems in wildlife are disconcerting.problems in wildlife are disconcerting.

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Removal Pathways of Groups of CECs Removal Pathways of Groups of CECs in Wastewater Treatmentin Wastewater Treatment

Steroid compoundsSteroid compounds PhytoestrogensPhytoestrogens SurfactantsSurfactants Pesticides, herbicides, fungicidesPesticides, herbicides, fungicides Polyaromatic compoundsPolyaromatic compounds Organic oxygen compounds (Bisphenol A, Organic oxygen compounds (Bisphenol A,

Phthalates, Dioxins, Organotins)Phthalates, Dioxins, Organotins)

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Potency of Steroid CompoundsPotency of Steroid Compounds

Estradiol 1 ng/l <0.2 - 3 ng/l

Ethinyl estradiol 0.1 ng/l <0.2 - 3 ng/l

Nonylphenol 14,000 ng/l <80 - 923 ng/l

Bisphenol A 25,000 ng/l 8 - 33 ng/l

(German study - Berlin-Ruhleben WWTP - Hansen et al, 1998)

Lowest observed effective concentration (LOEC) -

Rainbow troutEDC

WWTP effluent concentrations

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SurfactantsSurfactants Main surfactants of interest for ED are the alkylphenols (APs) and Main surfactants of interest for ED are the alkylphenols (APs) and

their ethoxylates (APEOs) – particularly the nonylphenol (NP) their ethoxylates (APEOs) – particularly the nonylphenol (NP) compoundscompounds

Alkyl Phenol Ethoxylates (APEO) widely used in industries as well Alkyl Phenol Ethoxylates (APEO) widely used in industries as well as commercial and household functionsas commercial and household functions

Detergents, lubrication, defoamers, emulsifiers, paints, pesticidesDetergents, lubrication, defoamers, emulsifiers, paints, pesticides Cleaners for machinery, metal working, textiles, and personal productsCleaners for machinery, metal working, textiles, and personal products

Nonylphenol ethoxylate is the most commonNonylphenol ethoxylate is the most common APEOs tend to be degraded to more potent endocrine disrupting APEOs tend to be degraded to more potent endocrine disrupting

compounds during wastewater treatmentcompounds during wastewater treatment The ethoxylates can be degraded to produce NP which is more The ethoxylates can be degraded to produce NP which is more

persistent and toxic than the ethoxylatespersistent and toxic than the ethoxylates Highest freshwater concentrations of NP observed near WWTPs, Highest freshwater concentrations of NP observed near WWTPs,

pulp mills, and regions of heavy industrypulp mills, and regions of heavy industry

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PesticidesPesticides Largest group of EDCsLargest group of EDCs DDT, dieldrin, 2,4-D, tributyltin, atrazine, metolachlor, DDT, dieldrin, 2,4-D, tributyltin, atrazine, metolachlor,

cyanazine, alachlorcyanazine, alachlor All herbicides, fungicides, pesticidesAll herbicides, fungicides, pesticides Atrazine one of the most difficult to removeAtrazine one of the most difficult to remove

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Understand Properties to Understand Properties to Predict Physical ProcessesPredict Physical Processes

Kow values are an indicator of hydrophobicity, and have been used as a surrogate for removal during water treatment

Property Potential Units Low High

Water Solubility Dissolving mg/l <1 1000

Henry's Law ConstantEvaporation/ Volatilization atm m3/mole >10-2 <10-7

Organic/Carbon Partition Coefficient

Degradation log Koc <3 >3

Log octanol/water partition

Sorption log Kow <2.5 >4

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CEC removal in Biological Treatment CEC removal in Biological Treatment – Dependent on parameters such as:– Dependent on parameters such as:

Temperature Sludge age, SRT HRT Influent concentrations Co-metabolite transformations Treatment type (AS, TF, MBRs)

Probably lower EDC concentrations from MBR systems due to retention of both particulate and colloidal material. Membrane systems appear to form colloid complexes to a greater extent than conventional systems

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WWTP Removals for Select EDCsWWTP Removals for Select EDCs

Trickling filter (TF) 90%

Activated sludge (AS) 96%

TF-AS 99%

NP AS - High load non-nitrifying 37%

As - Low load nitrifying 77%

AS - High load non-nitrifying -3%

AS - Low load nitrifying 31%

AS - High load non-nitrifying -5%

AS - Low load nitrifying 91%

AS - High load non-nitrifying 78%

AS - Low load nitrifying 98%

AS - High load non-nitrifying -5%

AS - Low load nitrifying 91%

Steroid estrogen - E1 AS - SRT 6 to 11 days, 20oC 75 to 98%

Steroid estrogen - E2 AS - SRT 6 to 11 days, 20oC 75 to 94%

Sand filtration - Microfiltration 70%

Reverse osmosis 95%

Primary treatment -5%

Secondary treatment 91%

Tertiary treatment 98%

Triazines Conventional two stage <40%

Organotins

Treatment Process

NP6EO

NP2EO

17 estradiol/17 ethinylestradiol (removals from influent)

EDC Removal Efficiency

PCB

NP1EO

NP2EO

Removals of E1 and E2 Removals of E1 and E2 reduced to 64 to 94% at reduced to 64 to 94% at 1515ooC (SRT 6 to 11 d)C (SRT 6 to 11 d)

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Removal Rates of Steroid Estrogens at Removal Rates of Steroid Estrogens at Varying Retention TimesVarying Retention Times

From: Johnson A.C., Belfroid From: Johnson A.C., Belfroid A., Di Corcia A. (2000)A., Di Corcia A. (2000)

E1 Loss E2 Loss E1 Loss E2 Loss

18-hour HRT 6-day SRT

64% 92% 75% -

18-hour HRT 11-day SRT

94% 98% >98% -

26-hour HRT 20-day SRT

66% >75% 98% >94%

13 - 15 ºC 18 - 19 ºC

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Influent and Effluent Concentrations of Influent and Effluent Concentrations of Alkylphenolic Compounds in WWTPsAlkylphenolic Compounds in WWTPs

WWTP Location

Number of

WWTPs

Type of Plants

Influent Concentration

(µg/l)

Effluent Concentration

(µg/l)

<10 - 35 NPSwitzerland 3 24 - 133 NP1EO

<10 - 70 NP2EO

14 NP 8 NPSwitzerland 1 18 NP1EO 49 NP1EO

18 NP2EO 44 NP2EO

Switzerland 5Mechanical -

biological844 - 2250 NPEO + NP 40 - 369 NPEO + NP

Switzerland 11 1090 - 2060 NP 240 - 760 NP

U.K. 12 <0.2 - 330 NP

Italy 1Mechanical -

biological800 NPEO 8 NPEO

U.S. 1 143 - 272 NPEC

Mechanical - biological

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NTA – Nitrilotriacetic acid – considered as a detergent builder in place of phosphates

Acclimation Times Required for NTA Acclimation Times Required for NTA Removal With Activated Sludge TreatmentRemoval With Activated Sludge Treatment

From: Rossin A.C., Lester J.N., From: Rossin A.C., Lester J.N., Perry R. (1982)Perry R. (1982)

SRT (days)

NTA Influent Concentration

(mg/l)

MLSS (mg/l)

Acclimation Time (days)

4 7.5 1514 15

4 15 - 20

9 7.5 3049 12

9 15 - 16

12 7.5 3536 6

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Comparison between MBR and CAS systemsComparison between MBR and CAS systems(from Scruggs C. (from Scruggs C. et alet al., WE&T, March 2005; Mansell ., WE&T, March 2005; Mansell et alet al., WEFTEC, 2005)., WEFTEC, 2005)::

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Hormones: Removal comparison between MBR Hormones: Removal comparison between MBR and CAS systemsand CAS systems (from Mansell (from Mansell et alet al., WEFTEC, 2005)., WEFTEC, 2005)::

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Granular activated carbon

Advanced oxidation

Reverse osmosis

CEC removal: CEC removal: Advanced treatment Advanced treatment processes following secondary treatmentprocesses following secondary treatment

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Coagulation or Chemical PrecipitationCoagulation or Chemical Precipitation Most compounds of concern are relatively polar (KMost compounds of concern are relatively polar (Kowow

values < 3)values < 3) Neither alum or iron coagulation or lime softening Neither alum or iron coagulation or lime softening

effective for atrazine or antibiotic removalseffective for atrazine or antibiotic removals Coagulation ineffective with several pharmaceuticals Coagulation ineffective with several pharmaceuticals

and with several pesticidesand with several pesticides Some pesticides (PAHs pyrene, fluoranthene and Some pesticides (PAHs pyrene, fluoranthene and

anthracene) removed ~50% by coagulationanthracene) removed ~50% by coagulation Coagulation only expected to remove hydrophobic Coagulation only expected to remove hydrophobic

compounds associated with particulate or colloidal compounds associated with particulate or colloidal materialmaterial

EDCs and PPCPs not associated with colloidal or EDCs and PPCPs not associated with colloidal or particulate material very poorly removed (<10%)particulate material very poorly removed (<10%)

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AdsorptionAdsorption Activated carbon (AC) effective for many different Activated carbon (AC) effective for many different

pesticides, PPCPs and EDCspesticides, PPCPs and EDCs Hydrophobic interactions dominant mechanism (weak Hydrophobic interactions dominant mechanism (weak

ion exchange interactions also contribute to ion exchange interactions also contribute to adsorption)adsorption)

AC can remove neutral organic compounds with AC can remove neutral organic compounds with hydrophobic compounds (logKhydrophobic compounds (logKowow>2)>2)

NOM in water competes for adsorption sites and NOM in water competes for adsorption sites and decreases AC effectiveness for micropollutantsdecreases AC effectiveness for micropollutants

PAC can be effective; GAC probably more efficientPAC can be effective; GAC probably more efficient PAC could be good emergency measure at WTPs, PAC could be good emergency measure at WTPs,

particularly during low streamflow, and with upstream particularly during low streamflow, and with upstream wastewater dischargeswastewater discharges

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Membrane FiltrationMembrane Filtration Most organic EDCs and PPCPs are 150 to 500 Most organic EDCs and PPCPs are 150 to 500

daltonsdaltons Most can be removed in RO and tight NF Most can be removed in RO and tight NF

membranesmembranes Microfiltration and ultrafiltration will only remove Microfiltration and ultrafiltration will only remove

those EDCs and PPCPs associated with colloidal those EDCs and PPCPs associated with colloidal and particulate matterand particulate matter

Polar and charged compounds that interact with Polar and charged compounds that interact with membrane surfaces will be better removedmembrane surfaces will be better removed

Hydrophobicity also affects removals. Removals Hydrophobicity also affects removals. Removals by RO and NF membranes correlates with logKby RO and NF membranes correlates with logKowow

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Effectiveness of Effectiveness of Treatment Treatment

Processes with Processes with Some CECsSome CECs

Effluent to be treated

Off-gasE

fflu

ent

Treatment Targeted CommentsProcess EDCs

GAC

APs, APEOs, PCP, methoxychlor,

endosulfan, diethyl phthalate, di-(2ethyl

hexyl) phthalate, PCBs

EPA BAT for some

contaminants

Reverse osmosis

Alkylphenol polyethoxy

carboxylates (APnECs), PCP

Most EDC compounds

removed by RO.

UV+catalystAPs, bisphenol A, E2, EE2, lindane,

2,4-D,

Ozone+H2O2 Atrazine2 min. EBCT.

EU regs may not be met

Coagulation, sedimentation and filtration

2,3,7,8 TCDDAdsorbed to floc

particles

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General removal efficiencies of General removal efficiencies of treatment processestreatment processes

EDC Classification

Coagulation/ Flocculation

Softening/ metal oxides

CL2/ ClO2

UVOzone/ AOPs

Activated Carbon

BAC NF RO

Pesticides <20% 70-90% 70->90% >90% 20->90% >90% >90% 70->90% >90%

Industrial chemicals

<20-40% <20-40% <20% >90% 40-90% >90% >90% >90% >90%

Steroids <20% <20-40% >90% >90% >90% >90% >90% 70->90% >90%

Metals 40-90% 40-90% <20% <20% <20% 70-90% 70-90% 70->90% >90%

Inorganics <20% 70-90% <20% <20% <20% <20-40% 40-70% 70->90% >90%

Organometalics <20-40% <20-40% <20-70% 40-90% 20->90% 70->90% 70->90% 70->90% >90%