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NYC Watershed/Tifft Science & Technical Symposium September 19, 2013 Treatment of Emerging Environmental Contaminants In Water.

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Presentation on theme: "NYC Watershed/Tifft Science & Technical Symposium September 19, 2013 Treatment of Emerging Environmental Contaminants In Water."— Presentation transcript:

1 NYC Watershed/Tifft Science & Technical Symposium September 19, 2013 Treatment of Emerging Environmental Contaminants In Water

2 WATER QUALITY – GLOBAL TRENDS Contaminants are now being detected regularly in the water supply Many regulators are now requiring routine testing of chemicals that were virtually unknown just a few years ago Growing awareness that the water supply is interconnected Supplies are tightening as population increases and water sources are more heavily tapped Unintentional water reuse is occurring “One city’s wastewater is another city’s drinking water”

3 OUR INTERCONNECTED WATER SUPPLY Sources of contaminants in our water supply: - Industrial discharge - Agricultural runoff - Chemical releases - Municipal wastewater Injection Well Extraction Well

4 WHAT IS UV-OXIDATION? It is the process of destroying trace organic contaminants in water by: UV-Photolysis UV light alone breaks down the contaminant molecules UV-Oxidation UV light plus hydrogen peroxide (H 2 O 2 ) Hydrogen peroxide absorbs UV and produces hydroxyl radicals that oxidize contaminants

5 UV-PHOTOLYSIS Chemical bonds are broken by UV light

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

7 HOW UV TREATS ENVIRONMENTAL CONTAMINANTS Simultaneous Processes Typically, UV-photolysis and UV- oxidation occur simultaneously: reaction time is milliseconds Most contaminants are broken down by a combination of both processes The relative contribution of either UV-photolysis and UV-oxidation varies by contaminant The UV energy output for both processes is sufficient to also provide microbial disinfection

8 CONTAMINANT DESTRUCTION BALANCE

9 EXAMPLES OF ECT CONTAMINANTS N-nitrosodimethylamine (NDMA) Industrial additive & disinfection byproduct 1,4-Dioxane Industrial solvent Pesticides & Herbicides Agricultural crop protection products Petroleum Additives Including MTBE Volatile Organics (TCE, PCE, Vinyl Chloride, etc.) Naphthalene and Phenols Pharmaceuticals & Personal Care Products Includes potential endocrine disruptors

10 NDMA AND 1,4-DIOXANE BACKGROUND No current federal regulations for either NDMA or 1,4-dioxane, however states have taken actions 1,4-dioxane is a solvent stabilizer used to prevent solvent breakdown during degreasing operations Conventional treatment technologies such as reverse osmosis (RO), coagulation/filtration, and carbon adsorption are ineffective

11 MTBE is a semi-volatile, chemically unreactive molecule Highly soluble in water (increase with Temp decrease), Sorbs poorly to soil grains, and has a low volatility (Treat air discharge?) Persistent and mobile in groundwater Break down to tert-butyl alcohol (TBA) METHYL TERTIARY BUTYL ETHER (MTBE) - OVERVIEW Properties of MTBE FormulaC5H12O Molecular Weight 88.15 Vapor pressure 245 mmHg at 25 ºC Solubility in water 43,000-50,000 mg/L Henry’s Law Constant 0.587 L-atm/mol at 25 ºC

12 METHYL TERTIARY BUTYL ETHER (MTBE) - OVERVIEW Oxidation of MTBE generates TBA. TBA adsorbs readily to GAC/BAC Sources: leaking underground storage tanks, accidental spills of fuels, and releases from recreational vehicles in reservoirs. Regulated in NY (10 ppb), CA (13 ppb), NH (13 pp), PA (20 ppb), RI (40 ppb) and numerous others The USEPA has set non-enforceable drinking water advisory levels for MTBE of 20 ppb based on odor and 40 ppb based on taste Listed on the USEPA’s CCL and UCMR

13 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 SIZING FACTORS FOR ECT SYSTEMS

14 LAMP TECHNOLOGY

15 Measured MP:LP = 2.8 LPHO PHOTOLYSIS OF HYDROGEN PEROXIDE The same number of hydroxyl radicals are produced with ~65% less power for LPHO vs. MP with this water quality

16 REACTOR DETAILS

17 REACTOR DETAILS LPHO Lamp power and number of reactors in operation automatically adjusted to minimize power Reactors can be oriented 1-, 2-, or 3-high for small footprint 250W LPHO lamp efficiently treating contaminants year round

18 Two lamp bundles per chamber (one accessed from each end) Influent Port Effluent Port REACTOR DETAILS LPHO

19 Remediation Case Studies

20 200 GPM facility treating extracted groundwater Water is treated through air stripping, then UV-oxidation Contaminant of concern: 1,4-dioxane, TCE NDMA reduced from 150 ppb to less than 1 ppb TrojanUVPhox™, amalgam lamp lamp technology Full service hydrogen peroxide and delivery and maintenance GROUNDWATER REMEDIATION INSTALLATION - STOCKTON, CA

21 1,4-DIOXANE PERFORMANCE TESTING RESULTS - STOCKTON, CA

22 Flow: 2378 gpm, 8ppm H2O2 dose Water is treated through Fe/Mn Filtration Contaminants of concern: 1,4-dioxane, TCE 1.3 Log reduction of 1,4 dioxane guarantee GAC for H2O2 quenching/redundancy (change out every 3 years, CL2 dosing back up) Full service hydrogen peroxide delivery and maintenance GROUNDWATER TREATMENT INSTALLATION – WATERLOO, ON

23 1,4-DIOXANE PERFORMANCE TESTING RESULTS – Greenbrook, ON

24 LOCATION OF CALIFORNIA DOMESTIC WATER CO The California Domestic Treatment Facility

25 CONTAMINATION IN THE SAN GABRIEL VALLEY – BACKGROUND VOCs discovered in 1979 Plume defined, now traverses several “Operable Units” including the Baldwin Park OU 1997, NDMA, 1,4-dioxane and perchlorate detected Cal Domestic Plume map courtesy of EPA Region 9 Mailer, May 1999

26 Flow Rate: 6.8 MGD (one train of two, =4,700gpm) 1. Ion Exchange 2. UV-Photolysis 3. Air Stripping 4. Chlorination (for residual in distribution system) THE TREATMENT PROCESS AT CAL DOMESTIC Medium Pressure Rayox™ October 2001 to April 2005

27 Flow Rate: 6.8 MGD (one train of two, =4,700gpm) 1. Ion Exchange 2. UV-Photolysis 3. Air Stripping 4. Chlorination (for residual in distribution system) THE TREATMENT PROCESS AT CAL DOMESTIC Low Pressure High Output TrojanUVPhox™ April 2005 to Present

28 NDMA TREATMENT PERFORMANCE CAL DOMESTIC

29 ENERGY USAGE (kWh) CAL DOMESTIC ~5X more power used with MP solution vs. LPHO solution Theory states that the lowest power ratio would be 3X Increase to 5X from 3X due to enhanced optical & hydraulic efficiencies with LPHO reactor when compared to MP reactor

30 OTHER REMEDIATION PROJECTS El Monte, California – 0.072 MGD (50 gpm) Secor, Colorado – 0.029 MGD (20 gpm) Sunnyvale, California – 0.14 MGD (100 gpm) La Puente Valley County Water District, CA – 3.6 MGD California Domestic Water Company, CA – 14.5 MGD

31 Suffolk County Water Authority Pilot Prove technology effectiveness on destruction of 1,4 dioxane and other VOCs Existing GAC for removing residual peroxide (extends GAC life) Water quality higher than initial design (99% UVT vs 95% UVT) Scavenging demand lower = lower H2O2 dose 1200 gpm Full scale system in design

32 Questions? Terry Keep ECT Sales Manager TrojanUV (519) 457-3400 tkeep@trojanuv.com www.trojanuv.com


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