use of o /doc and uv/doc as dosing parameters for advanced oxidation processes … · 2016. 11....

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Use of O3/DOC and UV/DOC as Dosing Parameters for Advanced Oxidation Processes in Potable Reuse Applications

Transformation of Bulk Organic Matter andPrediction of Trace Organic Compound Elimination

Dr. Daniel GerrityAssistant Professor

Department of Civil & Environmental Engineering and Construction

Email: [email protected]: http://faculty.unlv.edu/wpmu/dgerrity/

CA-NV AWWA – Annual Fall Conference – 2015

mailto:[email protected]

http://faculty.unlv.edu/wpmu/dgerrity/

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Potable Reuse Paradigms

Source: Gerrity et al. (2013) AQUA 62(6), 321-337

IPR DPR

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Role of Advanced Oxidation or UV in Potable Reuse

• Environmental Discharge (de facto Reuse)– Reduction in estrogenicity (e.g., fish feminization)– Trace organic compound (TOrC) mitigation– Disinfection

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• Environmental Buffer (Indirect Potable Reuse or IPR)– Bulk organic matter transformation (for subsequent biofiltration)– TOrC mitigation upstream/downstream of biofiltration– Disinfection

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• Environmental Buffer (Indirect Potable Reuse or IPR)– Bulk organic matter transformation (for subsequent biofiltration)– TOrC mitigation upstream/downstream of biofiltration– Disinfection

• Engineered Storage Buffer (Direct Potable Reuse or DPR)– Reductions in organic fouling on membranes– TOrC mitigation upstream/downstream of membranes– Disinfection

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(Reverse Osmosis and Advanced Oxidation)

“Full Advanced Treatment” for Potable Reuse


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Advanced Treatment for Potable Reuse


(Ozone and Biological Filtration)

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• Included in U.S. EPA Contaminant Candidate List 3 (CCL3) and Draft 4 (CCL4)

• Australia/CA DDW Target = 10 ng/L

• Current Analytical Limit ≈ 1 ng/L

• Drinking Water Equivalent Level (10-6 lifetime risk) = 0.69 ng/L

N-nitrosodimethylamine (NDMA)

Source: Gerrity et al. (2014) Water Res. 72, 251-261; WateReuse-08-05

Mitigation is possible: • Biological filtration• High dose UV photolysis

NDMA Formation During Ozonation (O3/DOC = 0.5)(even higher in other wastewaters)

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Full Advanced Treatment:

Focus of this Presentation:

Alternative Advanced Treatment:

UV or UV/H2O2

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UV or UV/H2O2

• Use of ozone and/or high dose UV in secondary/tertiary effluent applications

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UV or UV/H2O2

• Use of ozone and/or high dose UV in secondary/tertiary effluent applications

• How can we achieve similar water quality objectives in different wastewaters

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Target Compounds and Rate ConstantsTOrCs kO3,pH=7

(M-1 s-1)kOH

(M-1 s-1)

Bisphenol A 7x105 1x1010

Carbamazepine 3x105 9x109

Diclofenac 1x106 8x109

Naproxen 2x105 1x1010

Sulfamethoxazole 3x106 6x109

Triclosan 4x107 1x1010

Trimethoprim 3x105 7x109

Atenolol 2x103 8x109

Gemfibrozil 5x104 1x1010

DEET <10 5x109

Ibuprofen 10 7x109

pCBA <0.1 5x109

Phenytoin <10 6x109

Primidone 1 7x109

1,4-Dioxane <1 3x109

Atrazine 6 2x109

Meprobamate <1 4x109

TCEP <1 6x108

NDMA <0.1 5x108

TOrCs kUV(mJ/cm2)-1

kOH(M-1 s-1)

Diclofenac 7x10-3 8x109

Triclosan 5x10-3 1x1010

NDMA 5x10-3 5x108

Sulfamethoxazole 2x10-3 6x109

Phenytoin 1x10-3 6x109

Naproxen 4x10-4 1x1010

Bisphenol A 2x10-4 1x1010

Atrazine 7x10-4 2x109

Ibuprofen 1x10-4 7x109

pCBA 2x10-4 5x109

Carbamazepine 9x10-5 9x109

Gemfibrozil 6x10-5 1x1010

Trimethoprim 8x10-5 7x109

Atenolol 7x10-5 8x109

Primidone 8x10-5 7x109

DEET 6x10-5 5x109

Meprobamate <5x10-5 4x109

1

2

3

4

O3Grouping

UV/H2O2Grouping

1

3

4

5

6

2

5

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Target Compounds and Rate ConstantsTOrCs kO3,pH=7

(M-1 s-1)kOH

(M-1 s-1)

Bisphenol A 7x105 1x1010

Carbamazepine 3x105 9x109

Diclofenac 1x106 8x109

Naproxen 2x105 1x1010

Sulfamethoxazole 3x106 6x109

Triclosan 4x107 1x1010

Trimethoprim 3x105 7x109

Atenolol 2x103 8x109

Gemfibrozil 5x104 1x1010

DEET <10 5x109

Ibuprofen 10 7x109

pCBA <0.1 5x109

Phenytoin <10 6x109

Primidone 1 7x109

1,4-Dioxane <1 3x109

Atrazine 6 2x109

Meprobamate <1 4x109

TCEP <1 6x108

NDMA <0.1 5x108

TOrCs kUV(mJ/cm2)-1

kOH(M-1 s-1)

Diclofenac 7x10-3 8x109

Triclosan 5x10-3 1x1010

NDMA 5x10-3 5x108

Sulfamethoxazole 2x10-3 6x109

Phenytoin 1x10-3 6x109

Naproxen 4x10-4 1x1010

Bisphenol A 2x10-4 1x1010

Atrazine 7x10-4 2x109

Ibuprofen 1x10-4 7x109

pCBA 2x10-4 5x109

Carbamazepine 9x10-5 9x109

Gemfibrozil 6x10-5 1x1010

Trimethoprim 8x10-5 7x109

Atenolol 7x10-5 8x109

Primidone 8x10-5 7x109

DEET 6x10-5 5x109

Meprobamate <5x10-5 4x109

1

2

3

4

O3Grouping

UV/H2O2Grouping

1

3

4

5

6

2

5

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Kinetics of Ozone-Based Advanced Oxidation

O3 and O3/H2O2 (both generate OH):

Source: Lee et al. (2013) ES&T 47, 5872-5881; WateReuse-08-05

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For disinfection, ozone “Ct” ( ) is critical for spore-forming microbes, although

OH “Ct” ( ) is also effective for the inactivation of viruses and vegetative

bacteria.



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bacteria.

For TOrC oxidation, only the most reactive compounds (kO3>105 M-1 s-1) are oxidized

by molecular ozone. In these cases, even low ozone doses achieve nearly complete

‘elimination’.



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bacteria.


For TOrC oxidation, only the most reactive compounds (kO3>105 M-1 s-1) are oxidized

by molecular ozone. In these cases, even low ozone doses achieve nearly complete

‘elimination’.

Many TOrCs are primarily oxidized by OH (kO3<10 M-1 s-1), in which case the ozone

contribution in the equation above is negligible.


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Kinetics of UV Photolysis

UV:

ε254 = Decadic molar absorptivity of the target compound at 254 nm (cm-1 M-1)

φ254 = Quantum yield of the target compound at 254 nm (moles/einstein)

U254 = Molar photon energy at 254 nm = 4.72x105 J/einstein

kUV = pseudo first order photolysis rate constant (mJ/cm2)-1

UV Dose = UV dose at 254 nm (mJ/cm2)

(1 einstein = 1 mole of photons)

Source: Lee et al. (2015) In preparation; Gerrity et al. (2015) In preparation

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UV:

ε254 = Decadic molar absorptivity of the target compound at 254 nm (cm-1 M-1)

φ254 = Quantum yield of the target compound at 254 nm (moles/einstein)


kUV = pseudo first order photolysis rate constant (mJ/cm2)-1

UV Dose = UV dose at 254 nm (mJ/cm2)

(1 einstein = 1 mole of photons)

Few TOrCs are susceptible to UV photolysis alone (kUV<10-3 (mJ/cm2)-1), thereby necessitating the

addition of H2O2 to generate OH. A notable exception is NDMA, which is highly resistant to OH but

relatively susceptible to UV photolysis (kUV=5x10-3 (mJ/cm2)-1).

Kinetics of UV Photolysis


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Kinetics of UV/H2O2 Advanced OxidationUV/H2O2:

In the UV/H2O2 process, OH generation is based on the kinetics of H2O2 photolysis at 254

nm (H2O2 is split into 2 OH).


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Kinetics of UV/H2O2 Advanced Oxidation

UV/H2O2:

OH Generation Rate (M s-1)

OH Scavenging Rate Constant (s-1)

In the UV/H2O2 process, OH generation is based on the kinetics of H2O2 photolysis at 254

nm (H2O2 is split into 2 OH).


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Kinetics of UV/H2O2 Advanced Oxidation

UV/H2O2:

εH2O2 = 19.6 cm-1 M-1

φH2O2 = 1.0 moles/einstein

[H2O2] = H2O2 concentration (M)

UV Dose = UV Dose at 254 nm (mJ/cm2)


= OH scavenging rate constant (s-1)

Process-specific

Wastewater-specific


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Kinetics of Advanced Oxidation

Take home messages:

With ozone and UV-based advanced oxidation, OH is often the major species

contributing to TOrC destruction so its generation rate and scavenging rate are

critical parameters affecting process performance.

Source: Lee et al. (2013) ES&T 47, 5872-5881; Gerrity et al. (2015) In preparation

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Take home messages:





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Take home messages:




Dissolved organic carbon (DOC) is generally the major scavenger in both types of

advanced oxidation (sometimes nitrite is significant for UV/H2O2).

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Take home messages:




Dissolved organic carbon (DOC) is generally the major scavenger in both types of

advanced oxidation (sometimes nitrite is significant for UV/H2O2).

O3 and O3/H2O2: UV/H2O2: Avg. NO2- Correction



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Relative Contributions to OH Scavenging

10 Different Secondary Effluents 10 Different Secondary Effluents

O3 and O3/H2O2 UV/H2O2

Major Scavengers

DOC

• DOC dominates OH scavenging in ozone AOP (nitrite reacts rapidly and completely with O3before OH is present)

• DOC and nitrite dominate OH scavenging for UV AOP


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1) Dissolved organic carbon is the major scavenger for advanced oxidation processes

when treating secondary/tertiary effluent.

Source: Lee et al. (2013) ES&T 47, 5872-5881

Assumptions


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2) The second order rate constant between OH and dissolved organic carbon in

secondary/tertiary effluent is relatively constant between different wastewaters:

kOH,DOC = (2.1±0.6)x104 (mgC/L)-1 s-1.


Assumptions


10 Different Secondary Effluents

k O

H,D

OC

(mgC

/L)-1

s-1

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2) The second order rate constant between OH and dissolved organic carbon in

secondary/tertiary effluent is relatively constant between different wastewaters:

kOH,DOC = (2.1±0.6)x104 (mgC/L)-1 s-1.


10 Different Secondary Effluents

k O

H,D

OC

(mgC

/L)-1

s-1 Therefore, we can achieve similar TOrC

removals in different wastewaters by normalizing dose to DOC:• O3/DOC• UV/DOC

We can also correlate changes in bulk organic parameters to TOrC removal:• ΔTOrC vs. ΔUV254 Absorbance• ΔTOrC vs. ΔFluorescence

Assumptions


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OH Exposure vs. O3/DOC for 10 Secondary Effluents

O3/DOC


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O3/DOC Validation for 9 Secondary Effluents


O3/DOC Ratio ≈ 0.25, 0.5, 1.0, 1.5)

Mep

roba

mat

eAt

razi

neTC

EP

% E

limin

atio

n%

Elim

inat

ion

% E

limin

atio

n

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Simplified Equations for UV/H2O2

Source: Gerrity et al. (2015) In preparation

(simplified from earlier slides)

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For UV-resistant TOrCs:




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OH Exposure vs. UV/DOC for 10 Secondary Effluents

Theoretical Relationship:

Experimental Relationship:10 mg/L of H2O2


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For UV-resistant TOrCs:




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UV/DOC Validation for 10 Secondary Effluents

Source: Gerrity et al. (2015) In preparationH2O2 = 10 mg/L

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UV/DOC Implementation for Hypothetical TOrCs

Source: Gerrity et al. (2015) In preparationH2O2 = 10 mg/L

% E

limin

atio

n

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Summary of O3/DOC and UV/DOC Rate Constants

Applicable to:• O3 and O3/H2O2 (independent of H2O2 dose)• Ozone susceptible and resistant TOrCs• Different secondary/tertiary effluents

Applicable to:• Only UV/H2O2• UV-resistant TOrCs• Different secondary/tertiary effluents


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*10 mg/L of H2O2

Summary of O3/DOC and UV/DOC Rate Constants


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Correlations with Bulk Organic Matter Transformation

ΔUV254 Absorbance (%) ΔFluorescence (%)

ΔTO

rC(%

)

ΔTO

rC(%

)

• Applicable to O3, O3/H2O2, and UV/H2O2• Independent of H2O2 dose• Appropriate for ozone susceptible/resistant TOrCs• Appropriate for UV-resistant TOrCs• Similar correlations for different secondary/tertiary effluents


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Ozone Correlation Example: TOrC = Phenytoin

Bench-ScaleDevelopment

Pilot-ScaleValidation

Real-TimeDemonstration

9 Secondary Effluents4 Ozone Doses3 H2O2 Doses

5 Independent Studies s::can Analyzer


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Ozone Correlation Parameters


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UV/H2O2 Correlation Example: TOrC = Phenytoin

Validation(UV254 Absorbance)

Bench-Scale(UV254 Absorbance)

5 Secondary Effluents 2 Independent Studies 5 Secondary Effluents

Bench-Scale(Total Fluorescence)

Source: Gerrity et al. (2015) In Preparation; WateReuse-09-10

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UV/H2O2 Correlation Parameters

Source: Gerrity et al. (2015) In Preparation; WateReuse-09-10

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Potential Real-Time Monitoring Application

UV or UV/H2O2

s::can online UV absorbance analyzers

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UV or UV/H2O2

UVA254 = 0.14 cm-1 UVA254 = 0.082 cm-1

ΔUVA254 = 41%


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UV or UV/H2O2

UVA254 = 0.14 cm-1 UVA254 = 0.082 cm-1

ΔUVA254 = 41%

On-line Monitor

Atrazine = 42 ng/LAtenolol = 150 ng/L

(and other contaminants)

Historical Monitoring

O3/DOC = 0.7 Atrazine = 20 ng/LAtenolol = 10 ng/L

1,4-Dioxane = 0.3 logsViral Inactivation = 5.6 logs

(and other contaminants)

Model Outputs


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Conclusions

• Ozone- and UV-based advanced oxidation processes (AOPs) are critical for trace organic contaminant (TOrC) mitigation in potable reuse applications

• Many TOrCs are resistant to ozone and UV but are susceptible to the OH generated by the AOPs

• OH scavenging is dominated by dissolved organic carbon (DOC) in secondary/tertiary effluents

• The rate constant between OH and DOC is relatively constant between wastewaters

• Therefore, the following parameters are useful tools for process control and to estimate TOrC oxidation:– O3/DOC– UV/DOC– ΔUV254 Absorbance– ΔFluorescence

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Acknowledgments

• Collaborators– Sujanie Gamage, Janie Holady, Jasmine Koster, Minju Lee, Yunho Lee,

Aleksey Pisarenko, Jacqueline Traber, Rebecca Trenholm, Eric Wert, Urs von Gunten, Shane Snyder

• Funding Agencies– Swiss Federal Offices for the Environment– WateReuse Research Foundation (WRF-08-05 and WRF-09-10) and

Julie Minton and Stefani McGregor• Equipment Vendors

– APTwater (HiPOX), Hydranautics, Xylem (Wedeco), s::can Messtechnik

• Participating Agencies– City of Las Vegas, City of Reno Public Works Department, Clark

County Water Reclamation District, Gwinnett County, Kloten-OpfikonWastewater Treatment Plant, Lausanne Wastewater Treatment Plant, Lowood Wastewater Treatment Plant, Metropolitan Water Reclamation District of Greater Chicago, Pinellas County Utilities, RegensdorfWastewater Treatment Plant, United Water, West Basin Municipal Water District

use of o /doc and uv/doc as dosing parameters for advanced oxidation processes … · 2016. 11....

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