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

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

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

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

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

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

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

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

UV-PHOTOLYSIS Chemical bonds are broken by UV light

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

CONTAMINANT DESTRUCTION BALANCE

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

DUAL-MODE OPERATION

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

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)

ALGAL TOXINS OXIDIZED MORE EASILY THAN MIB

SYSTEM SIZING

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

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

CASE STUDIES

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

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

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

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.

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.

UV Reactor Chamber Cooling Water Outlet Cooling Water Inlet

UV Reactor Chamber Ballasts

UV Reactor Chamber Flow Meter

UV Reactor Chamber Cooling Water Inlet UV Reactor UV Reactor

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

Hydrogen Peroxide Metering Pumps Chemical Feed Hydrogen Peroxide Metering Pumps

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 (1.2 - 4.8 mg/L)

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

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

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

UV SYSTEM – TWO TRAINS OF THREE REACTORS

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

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

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

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

REGIONAL MUNICIPALITY OF WEST ELGIN, ON

PERFORMANCE RESULTS WEST ELGIN, ONTARIO (APRIL 2009)

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

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)

QUESTIONS? THANK YOU Terry Keep Trojan Technologies (519) 457-3400 Brady Sessums ETEC Cell 225-955-2160 Work 225-295-1200 bsessums@etec-sales.com Terry Keep Trojan Technologies (519) 457-3400 tkeep@trojanuv.com