1. UV ADVANCED OXIDATION FOR THE TREATMENT OF ALGAE-RELATED TASTE AND ODOUR COMPOUNDS IN DRINKING WATER
Terry Keep
NE Ohio Summer Conference
Mansfield, Ohio
August 20, 2015

2. UV DISINFECTION FOR DRINKING WATER
Ultraviolet light (UV)  one component in the multiple barrier municipal drinking water treatment train
Well established technology
An excellent option to achieve additional disinfection
UV’s ability to inactivate many microorganisms, especially Cryptosporidium and Giardia, without forming DBPs drives growth

3. GROWING APPLICATION OF UV ADVANCED OXIDATION
Indirect Potable Reuse (IPR) Wastewater treated to drinking water quality
Groundwater Remediation Plume containment, site cleanup
Drinking Water Contaminated groundwater or surface water sources, Taste & Odour treatment
Total Flow Rate for Trojan Municipal UV-Oxidation Projects in
2000: <40 MLD
2011: ~2.2 BLD

4. WATER STRESS IN AN INTERCONNECTED WATER SUPPLY
Sources of contaminants in our water supply:
Industrial discharge
Agricultural runoff
Chemical releases
Municipal Wastewater
Extraction
Well
Injection
Well
Nutrients  increase in Algae Blooms  Taste & Odour, Algal Toxins

5. EXAMPLES OF MICROPOLLUTANTS
Nitrosamines (e.g. NDMA) Disinfection byproducts
Pesticides & Herbicides Metaldehyde, Atrazine, Isoproturon, others
Petroleum Additives Including MTBE
Pharmaceuticals & Personal Care Products Includes potential endocrine disruptors
Taste & Odour Compounds Seasonal occurrences of MIB, geosmin and others
Algal Toxins Chronic and acute effects from cyanobacteria-derived toxins

6. TASTE & ODOUR, ALGAL TOXINS
Seasonal algae blooms occur in surface waters
Decaying algae blooms result in MIB, geosmin, algal toxins, other T&O compounds
Earthy/musty, fishy, swampy, grassy tastes & odours at low ppt concentrations
Difficult to remove with conventional technologies
T&O episodes compromise public confidence in the safety of the water

7. TASTE AND ODOUR TREATMENT STRATEGIES
Potassium Permanganate
Limited Effectiveness
Powdered Activated Carbon
Messy PAC & Sludge Handling, no Performance Guarantee
Granular Activated Carbon
Frequent & Expensive Change-outs, no Performance Guarantee
Ozone
Complicated System & Carcinogenic by-product (Bromate)
UV-Oxidation
Simple, Effective for T&O with Simultaneous Disinfection, Guaranteed Performance for life of system

8. UV / H2O2 FOR TASTE AND ODOUR TREATMENT
UV Advanced Oxidation: Using UV and Hydrogen Peroxide to destroy trace organic contaminants in water by:
UV-Photolysis
UV-Oxidation

9. UV-PHOTOLYSIS
Chemical bonds are broken by UV light

10. UV-OXIDATION Hydrogen peroxide Hydroxyl radical
Chemical bonds are broken by hydroxyl
radicals

11. CONTAMINANT DESTRUCTION BALANCE

12. APPLICATION OF UV ADVANCED OXIDATION FOR TASTE & ODOUR / ALGAL TOXIN TREATMENT

13. DUAL-MODE OPERATION

14. UV-OXIDATION A RANGE OF T&O COMPOUNDS
Performance
Target

15. COMPOUNDS GENERATED BY SOME CYANOBACTERIA
Aesthetics: T&O cmpds
Cylindrospermopsin (CYN)
Microcystin-LR (MC-LR)
[MC]~1800ug/L meas drng bloom
Public Health: Cyanotoxins
Geosmin
USEPA added CNTX to the CCL
WHO set limit at 1 µg/L
[Geosmin] have been measured > 3000 ng/L
2-Methylisoborneol (MIB)
GSM and MIB can be detected by sensitive individual down to 4 ng/L (ppt)

16. ALGAL TOXINS OXIDIZED MORE EASILY THAN MIB

17. SYSTEM SIZING

18. SIZING FACTORS FOR ECT SYSTEMS
Contaminant Quantum Yield
Contaminant - Hydroxyl Radical Rate Constant
Contaminant Molar Absorption Coefficient
Hydrogen Peroxide Concentration
Water Absorbance (UVT)
Water Matrix Hydroxyl Radical Scavenging Capacity
Lamp Type

19. UV-PHOTOLYSIS AND UV-OXIDATION KINETICS
The overall kinetic equation describing the photolytic and UV/H2O2 photo-oxidative reactions of a micropollutant C is:
Hydrogen peroxide
Hydroxyl
radical
UV-Oxidation
UV-Photolysis
Where:
Fraction of light absorbed by contaminant, scavengers, and peroxide (fxn of wavelength, dependent on absorbance)
Lamp Spectral Photon Flux
Reaction rates with hydroxyl radical for contaminant (C) and scavengers (S)
Quantum Yield of contaminant and peroxide

20. CASE STUDIES

21. Aqua PA’s Neshaminy WTP, Pennsylvania Hatch Mott MacDonald Presented at New Jersey, Ohio and Pennsylvania Annual AWWA Conferences 2010
Researchers Evaluated the following Treatment Technologies:
PAC
GAC
Ozone
UV AOP

22. Aqua PA’s Neshaminy WTP, Pennsylvania Hatch Mott MacDonald Presented at New Jersey, Ohio and Pennsylvania Annual AWWA Conferences 2010
Design Conditions:
Flow rate: 57 MLD, average 40 MLD
Design UVT: 93%
Influent [GSM]: 100ppt
Target effluent [GSM]: 10ppt
1.0-log GSM treatment at average flow, 0.7 log at peak flow

23. Estimates were based on a PAC dose of 30 mg/l and a 90-day taste and odor period

24. Analysis was based on 90 days of taste and odor operation with a discount factor of 4%. Costs include capital, construction, operation and maintenance (including dry solids removal for spent PAC). The PAC costs were based on $0.95 per pound and $215 per ton of dry solids removal and a dose of 30mg/L.

25. Estimates were based on a PAC dose of 30 mg/l and a 90-day taste and odor period. UV-oxidation was also evaluated over the same 90 day taste and odour period.

26. UV Reactor Chamber
Cooling Water Outlet
Cooling Water Inlet

27. UV Reactor Chamber
Ballasts

28. UV Reactor Chamber
Flow Meter

29. UV Reactor Chamber
Cooling Water Inlet
UV Reactor
UV Reactor

30. Hydrogen Peroxide Tank (50%)
Chemical Feed
Hydrogen Peroxide Tank (50%)

31. Hydrogen Peroxide Metering Pumps
Chemical Feed
Hydrogen Peroxide Metering Pumps

32. PATOKA LAKE, IN STUDY Malcolm Pirnie – Presented at the WQTC November 2008
Researchers Evaluated the following Treatment Technologies:
UV- AOP (8 mg/L)
PAC (30 – 110 mg/L)
GAC (7&15 min EBCT)
Ozone ( mg/L)

33. PATOKA LAKE, IN STUDY Malcolm Pirnie– Presented at the WQTC November 2008
Design Conditions:
Flow rate: 15 MGD, average 10 MGD
Design UVT: 93%
Influent [MIB]: 300ppt
Target effluent [MIB]: 5ppt
1.8-log MIB treatment

34. Treatment Target = 1.5-Log MIB
PERFORMANCE TESTING
Test Description
UV (% Power)
H2O2
No Treatment
NONE
UV Alone
100
H2O2 Alone
8 ppm
50% UV+H2O2 50
100% UV+H2O2
UV-AOX makes use of a UV reactor and hydrogen peroxide which is dosed upstream of the reactor.
The peroxide is converted to hydroxyl radicals when exposed to UV and these radicals oxidize contaminants and break them down into harmless products.
Not all peroxide is converted in the UV reactor and is quenched after passing through the reactor by chlorine, which also functions as a necessary residual disinfection chemical in the drinking water distribution system
Treatment Target = 1.5-Log MIB

35. PERFORMANCE TESTING - RESULTS
Treatment Target
UV-AOX makes use of a UV reactor and hydrogen peroxide which is dosed upstream of the reactor.
The peroxide is converted to hydroxyl radicals when exposed to UV and these radicals oxidize contaminants and break them down into harmless products.
Not all peroxide is converted in the UV reactor and is quenched after passing through the reactor by chlorine, which also functions as a necessary residual disinfection chemical in the drinking water distribution system

36. UV SYSTEM – TWO TRAINS OF THREE REACTORS

37. PERFORMANCE TESTING - CONCLUSIONS
Neither UV or H2O2 used independently had the capability of achieving the required treatment target of 1.5-log reduction of MIB
Combination of UV and H2O2 showed near 1.5-Log removal of MIB when UV functioning at 50% output
100% UV output and same H2O2 dose showed over 2-log removal of MIB
Chlorine quenching used to remove residual H2O2 successfully co-functions as a residual disinfectant

38. LORNE PARK WATER TREATMENT PLANT Region of Peel, (Serving Mississauga/Brampton, Ontario, Canada
Largest UV-oxidation installation for T&O treatment in the world
Flow rate = 390 MLD
Both UV-oxidation and ozone technologies were evaluated
UV-oxidation was ultimately selected due to its:
Smaller footprint
Safety (no liquid oxygen required on site)
No carbon to foul membrane
Performance Guarantee
Lorne Park is located in the Greater Toronto Area
It is a large facility designed to treat 103 MGD during peak months (summer)
This is when T&O problems are present
In addition to UV-Oxidation, this facility evaluated the potential for using ozone for T&O removal
It was recognized that the use of ozone could potentially lead to the formation of harmful by-products, namely bromate
In addition, UV was recognized as an overall more safer and simpler solution
Footprint was a key factor – there was not room for ozone contact basins
Also, this facility is located under (yes under) a park making the potential for ozone off-gas particularly undesirable
Lastly, storing H2O2 is safer than storing liquid O2 and is much more stable and does not present an explosion hazard

39. LORNE PARK WATER TREATMENT PLANT Region of Peel, Serving Mississauga/Brampton, Ontario, Canada
Operates in “disinfection-only” mode for most of the year when T&O events do not occur
Significant energy savings
Peroxide dosing can be turned on immediately when an event is detected
GAC-quenching removes residual peroxide before entering distribution

40. REGIONAL MUNICIPALITY OF WEST ELGIN, ON
Source water is Lake Erie
Flow rate 14.4 MLD
Treatment train: coagulation/settling  membranes  UV-oxidation  final disinfection
Algal blooms in late summer/early autumn
Previously used Powder Activated Carbon for T&O (membrane fouling)
Designed for 1.3-log Geosmin and 1.0-log MIB, algal toxins

41. REGIONAL MUNICIPALITY OF WEST ELGIN, ON

42. PERFORMANCE RESULTS WEST ELGIN, ONTARIO (APRIL 2009)

43. PLANTS RECENTLY SELECTING UV-OXIDATION
Franklin, TN – 4 MGD; 1 log MIB/1.3 log GSM
Patoka Lake, IN, USA – 20 MGD; 1.8-log MIB
Lorne Park, Ontario – 100 MGD; 1.3-log GSM/1.0-log MIB
Groesbeck, TX, USA – 2 MGD; 1.0-log GSM
Waxahachie, TX, USA – 14 MGD; 1.4-log GSM
Mansfield, TX, USA – 7.5 MGD; 1.0-log GSM
Neshaminy & Shenango PA, USA – 15 and 16 MGD, 1 log GSM
Lucerne, CA, USA – 1.0 MGD; 1.3-log GSM
Alliance Ohio, USA – 7 MGD; 1.5 log MIB
Otter Lake Water Commission, Illinois, USA – 1.5 log MIB 5 MGD
Wellborne, TX - 2 MGD; 1.1 log GSM/0.8 log MIB

44. CONCLUSIONS UV-Oxidation (UV + H2O2) is being implemented worldwide
UV-Oxidation successfully destroys taste and odor compounds, algal toxins, other micro pollutants
Performance Guarantee: Guaranteed Removal vs. competitive products
On/Off technology (no event, no O&M)
Disinfection design for UVDGM
Barrier for PPCPs/future regulations
Excellent option post membrane (no PAC needed)

45. QUESTIONS? THANK YOU Terry Keep Trojan Technologies (519) 457-3400
Brady Sessums
ETEC
Cell
Work
Terry Keep Trojan Technologies
(519)