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G‐0005‐stock‐2010

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plate Final.ppt

Efficacy and Energy Requirements for Trace Contaminant Removal in Water Reuse Systems

Ben Stanford, Ph.D. andJean Debroux, Ph.D.withShane Snyder, Dan Gerrity, and Megan Plumlee

Texas Water Reuse ConferenceJuly 12, 2013

Austin, TX

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WRF‐08‐05Use of Ozone in 

Water Reclamation for Contaminant 

OxidationSouthern Nevada Water Authority

WRF‐08‐08Oxidative 

Technologies for Reducing Membrane 

FoulingSouthern Nevada Water Authority

WRF‐09‐10Use of UV and 

Fluorescence Spectra as Surrogates for Contaminant Oxidation and Disinfection

Southern Nevada Water Authority

WRF‐10‐11Ozone Pretreatment of a Non‐Nitrified Secondary Effluent 

before Microfiltration

TrussellTechnologies

WRF‐11‐01Monitoring for Reliability and 

Process Control of Potable Reuse ApplicationsUniversity of Arizona

WRF‐11‐02Equivalency of Advanced 

Treatment Trains for Potable Reuse

TrussellTechnologies

WRF‐11‐08Formation of 

Nitrosamines and Perfluorochemicalsduring Ozonation in 

Water ReuseSouthern Nevada Water Authority

• Ozone/AOP• Potable Reuse• Process Control• Monitoring• Contaminants• Microbes

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Contaminants in CA Reuse Context

• CA Regulates microbes and CECs “12‐10‐10” rule for viruses, Giardia, and Cryptosporidium Specific log removal for CECs

• 0.5‐log (69%) for most indicators• 0.3‐log (50%) for recalcitrant indicators

BUT, removal is based on Full Advanced Treatment or “FAT” – MF + RO + UV/AOP Is there a “non‐FAT” option? Is it effective for CECs and pathogens? How Much Does it Cost?

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City of Las Vegas Water MBR‐Ozone‐RO

Ozonation of Secondary/Tertiary Effluents

MF O3 BAC

Membrane Fouling

(Contaminant Oxidation)

Contaminant Oxidation and Disinfection

UV/H2O2

Final Disinfection

O3

MFO3 BAC

Contaminant Oxidation /

Increased UV Transmittance

UV

O3

O3MF

Primary Clarifier EffluentAerobic Basin 1

Anoxic Basin

MembraneAerobic Basin 2

MBR Effluent MBR ControlsHiPOx(Ozone AOP)

HiPOx Effluent

NaOCl NH4Cl Anti‐Scalant Reverse Osmosis Pilot Effluent

6

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MBR‐HiPOx‐RO: Reuse Treatment

UnitsMBR

InfluentMBR

FiltrateHiPOxEffluent

HiPOxEffluent

RO Permeate

RO Permeate

6.0 mg/L O3

6.0 mg/L O3+2.1 mg/L

H2O2

(no oxidation treatment)

(1.5 mg/L O3 pre-

oxidation)Atenolol ng/L 3000 600 <25 57 <25 <25Atrazine ng/L <10 <10 <10 <10 <10 <10Carbamazepine ng/L 180 150 <10 <10 110 <10DEET ng/L 130 85 30 28 <25 <25Meprobamate ng/L 2000 430 383 360 <10 <10Dilantin ng/L 240 170 65 47 <10 <10Primidone ng/L 310 170 84 68 <10 <10Sulfamethoxazole ng/L 2800 1400 <25 38 <25 <25Trimethoprim ng/L 1500 100 <10 <10 <10 <10TCEP ng/L 800 540 480 450 <200 <200Bisphenol A ng/L 250 <50 <50 <50 <50 <50Diclofenac ng/L 700 160 <25 <25 <25 <25Gemfibrozil ng/L 5200 62 <10 <10 <10 <10Ibuprofen ng/L 30000 30 <25 <25 <25 <25Musk Ketone ng/L <100 <100 <100 <100 <100 <100Naproxen ng/L 29000 31 <25 <25 <25 <25Triclosan ng/L 67 160 <25 <25 <25 <25

Indirect Potable ReuseFull Available

Treatment (FAT):

Membrane Fouling

(Contaminant Oxidation)

O3MBR

Indirect Potable Reuse

Advantages of O3-BAC Disadvantages of O3-BAC

Source: Sundaram et al. (2009) WateReuse Research Symposium

FAT:

Non-FAT:

MF O3 BAC Recharge

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Effluent

Indirect Potable Reuse Pilot Project

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Deep Bed Filter ‐ Ozone ‐ BAC

Atrazin

e

Carbam

azep

ine

Dilanti

n (Phe

nytoi

n)Fluo

xetin

eGem

fibro

zilIo

prom

ideNap

roxe

n

n-Nitro

sodim

ethyla

mine

Sulfam

ethox

azole

Triclos

anC

once

ntra

tion

(ng/

L)

0

10

20

30

200

400

600

800

1000

1200

Influent Post Ozone Post BAC

0

5

10

15

20

25

30

35

NDMA Co

ncen

tration (ng/L)

Background NDMA Concentration in Pilot Studies

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Trace Organic Contaminant Removal by Ozone (Pisarenko, Stanford, et al)

Indirect Potable Reuse

Advantages of O3-BAC

Nearly complete TOrC removal

Eliminates concentrated brine stream

Reduced energy consumption

Disadvantages of O3-BAC

No reduction in salinity

Potential for bacterial regrowth

Higher TOC in effluent

NDMA formation?Source: Sundaram et al. (2009) WateReuse Research Symposium

FAT:

Non-FAT:

MF O3 BAC Recharge

Difficulty with Control & Monitors:Ozone Disinfection in Wastewater

• CT concept is not applicable to ascertain if disinfection or contaminant removal has beenachieved

Drinking Water Wasetwater

[O3] [O3]

Time Time

CT

CT

How can we verify our transferred ozone dose in real‐time?

0

0.03

0.06

0.09

0.12

0.15

240 280 320 360 400 440 480 520 560 600

Wavelength (nm)

Abs

orba

nce

(cm

-1)

O3:TOC = 0O3:TOC = 0.25O3:TOC = 0.5O3:TOC = 1.0O3:TOC = 1.5

Increasing Ozone / •OH Exposure

O3:TOC = 0 O3:TOC = 0.25 O3:TOC = 0.5 O3:TOC = 1.0 O3:TOC = 1.5

UV=0 mJ/cm2 UV=23 mJ/cm2 UV=45 mJ/cm2 UV=225 mJ/cm2 UV=680 mJ/cm2

Change in Fluorescence during Ozonation

Change in Fluorescence during UV/H2O2 (10 mg/L H2O2)

How can we verify our transferred ozone dose in real‐time?

3D Excitation Emission Matrices (EEMs)

Humic‐Like Substances

Fulvic‐Like Substances

Microbial Byproducts

Regional Integration Method

Chen et al. (2003) ES&T 37: 5701‐5710

O3:TOC = 0 O3:TOC = 0.25 O3:TOC = 0.5 O3:TOC = 1.0 O3:TOC = 1.5

UV=0 mJ/cm2 UV=23 mJ/cm2 UV=45 mJ/cm2 UV=225 mJ/cm2 UV=680 mJ/cm2

Change in Fluorescence during Ozonation

Change in Fluorescence during UV/H2O2 (10 mg/L H2O2)

How can we verify our transferred ozone dose in real‐time?

O3:TOC 0.25 0.5 1.0 1.5

UV254 Reduction 22% 32% 46% 57%

UV254 absorbance is:• more consistent than fluorescence at low O3:TOC ratios

• less consistent than fluorescence at high O3:TOC ratios

Possibly related to higher H2O2 doses at high O3:TOC ratios during O3/H2O2experiments

How can we verify our transferred ozone dose in real‐time?

O3:TOC 0.25 0.5 1.0 1.5

TF Reduction 51% 65% 83% 96%

Total fluorescence is:• less consistent than UV254 at low O3:TOC ratios

• but more consistentthan UV254 at high O3:TOC ratios

How can we verify our transferred ozone dose in real‐time?

Carbamazepine (Group 1) DEET (Group 3)

How can we estimate contaminant oxidation in real-time?

Carbamazepine (Group 1) DEET (Group 3)

How can we estimate contaminant oxidation in real-time?

Carbamazepine (Group 1) DEET (Group 3)

How can we estimate contaminant oxidation in real-time?

E. coli

How can we estimate microbial inactivation in real-time?

E. coli

MS2

How can we estimate microbial inactivation in real-time?

MS2

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How Do We Estimate TOrC/CEC Removal Costs?

O3 Dose 1.5 mg/L 3 mg/L 6 mg/L 9 mg/LO3:TOC Ratio 0.25 0.5 1.0 1.5

Average Percent Destruction of Target Compounds (CECs)

Group 1 >90% >90% >90% >90%

Group 2 >60% >90% >90% >90%

Group 3 >30% >60% >90% >90%

Group 4 >15% >30% >60% >80%

Group 5 <5% >5% >15% >20%

Oxidation efficacy at 50 MGD O3‐BAC Treatment Plant

‐ Based on 10 minute EBCT for BAC process

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Ozone System Size

CapacityOzone 

Contactor Capital Cost

Equipment Capital Cost

Total Project Cost

Capital Unit Cost

lb/day MGD mil $ mil $ mil $ mil$/MGD250 10 0.098 1.27 7.63 0.764400 16 0.133 1.38 8.46 0.529534 21 0.161 2.34 14.0 0.6551020 41 0.244 1.25 8.35 0.2051300 52 0.285 2.80 17.2 0.3325000 200 1.002 3.50 25.2 0.1267200 288 1.404 5.00 35.8 0.1249750 389 1.972 7.50 52.9 0.13613400 535 2.682 10.0 70.9 0.132

y = 2.011x‐0.474R² = 0.876

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 100 200 300 400 500 600

Capital Costs ($M/M

GD)

Flow (MGD)

Relative Ozone Capital Costs ‐ 10 to 535 MGD ‐ 2011 Costs (ENRCCI = 9116)

CapEX and O&M Costs Developed for Multiple Technologies

• Curves developed as stand‐alone unit processes

• Ozone• BAC

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BAC costing assumptions and results

• Based on drinking water GAC designs• Costs estimated for 10 and 20 minute Empty Bed Contact Times (EBCTs)

• Cost curves separated into <10 MGD and ≥10 MGD to develop better curve fit 

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Other Cost Curves Developed• UV/AOP (assumes 400 mJ/cm2 and 10 mg/L peroxide dose)

• MF• RO

y = 0.251x‐0.056R² = 0.274

0.000.050.100.150.200.250.300.350.400.450.50

0 20 40 60 80 100Capital Costs ($

M/M

GD)

Flow (MGD)

y = 1.893x‐0.223R² = 0.962

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 20 40 60 80 100

Capital Costs ($

M/M

GD)

Flow (MGD)

y = 0.303x‐0.219R² = 0.803

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0 10 20 30 40 50 60

O&M Costs ($

M/M

GD)

Flow (MGD)

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Group 1 Group 2 Group 3 Group 4 Group 5

Indicator Naproxen Atenolol Ibuprofen Atrazine TCEP

10% Reduction 0.25 0.65

30% Reduction 0.25 0.50 >1.50

50% Reduction 0.25 0.35 0.80

70% Reduction 0.40 0.55 1.20

90% Reduction 0.25 0.65 1.05 >1.50

WateReuse 08‐05: O3:TOC Ratios for Contaminant Removal

We can modify the cost curves to account for changes in ozone dose

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O3 Dose 3 mg/L Ozone

6 mg/L Ozone

12 mg/L Ozone

O3:TOC Ratio 0.3 0.6 1.2Capital Costs $29M $30.6M $32.2MAnnual O&M $2.8M $3.1M $3.6MGroup 1, % Removal >90% >90% >90%Group 2, % Removal 50 – 70% 70 – 90% >90%Group 3, % Removal ~50% ~70% >90%Group 4, % Removal 10 – 30% 30 – 50% ~70%Group 5, % Removal <10% ~10% 10 – 30 %

WateReuse Research Project 08‐05, Costs for Contaminant Destruction @ 50 MGD Facility with 10 mg/L TOC (EfOM)

(Accounts for Ozone + BAC)

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Process Trains and Capital Costs ($M/MGD)

Capacity (MGD)

O3‐BACMF‐O3‐BAC

MF‐ROMF‐RO‐UV/AOP

MF‐O3‐RO

1 $4.0 $5.9 $5.7 $5.9 $7.8

5 $1.8 $3.1 $4.0 $4.2 $4.9

10 $1.3 $2.4 $3.4 $3.6 $4.1

25 $0.82 $1.8 $2.8 $3.0 $3.2

50 $0.58 $1.4 $2.4 $2.6 $2.7

80 $0.46 $1.2 $2.2 $2.4 $2.4

Flow‐Normalized Capital Costs

Combinations of Processes

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Flow‐Normalized O&M Costs

Process Trains and Annual O&M Costs ($M/MGD)

Capacity (MGD)

O3‐BACMF‐O3‐BAC

MF‐ROMF‐RO‐UV/AOP

MF‐O3‐RO

1 $0.08 $0.38 $0.54 $0.58 $0.55

5 $0.06 $0.27 $0.51 $0.55 $0.52

10 $0.06 $0.24 $0.48 $0.51 $0.48

25 $0.06 $0.20 $0.42 $0.46 $0.43

50 $0.06 $0.18 $0.38 $0.41 $0.39

80 $0.05 $0.17 $0.36 $0.39 $0.36

Combinations of Processes

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Closing Remarks• What is the major driver for treatment choice selection in potable reuse applications?

• What water quality goals are required?• Are there ways to minimize capital and O&M costs to achieve the water quality goals?

• Ozone + BAC may be a possible option for indirect potable reuse

• Other factors should be considered Specific water chemistry Removal objectives End use of water Engineered or environmental buffers

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bstanford@hazenandsawyer.com

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Ozone Generators

Ozone System Size

CapacityOzone 

Contactor Capital Cost

Equipment Capital Cost

Total Project Cost

Capital UnitCost

‐ lb/day MGD mil $ mil $ mil $ mil$/MGD2x125 250 10 0.098 1.27 7.63 0.7642x200 400 16 0.133 1.38 8.46 0.5292x267 534 21 0.161 2.34 14.0 0.6551x1020 1020 41 0.244 1.25 8.35 0.2052x650 1300 52 0.285 2.80 17.2 0.3322x2500 5000 200 1.002 3.50 25.2 0.1263x2400 7200 288 1.404 5.00 35.8 0.1243x3250 9750 389 1.972 7.50 52.9 0.1364x3350 13400 535 2.682 10.0 70.9 0.132