NYC Watershed/Tifft Science & Technical Symposium September 19, 2013

NYC Watershed/Tifft Science & Technical SymposiumSeptember 19, 2013

Treatment of Emerging Environmental Contaminants

In Water

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”

OUR INTERCONNECTED WATER SUPPLY

Sources of contaminants in our water supply:

- Industrial discharge

- Agricultural runoff

- Chemical releases

- Municipal wastewater

InjectionWell

ExtractionWell

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-OxidationUV light plus hydrogen peroxide (H2O2)

Hydrogen peroxide absorbs UV and produces hydroxyl radicals that oxidize contaminants

UV-PHOTOLYSIS

Chemical bonds arebroken by UV light

UV-OXIDATION

Hydrogen peroxide

Hydroxylradical

Chemical bonds arebroken by hydroxyl radicals

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

0.0

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1.0

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1.4

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7 ppm H2O2 14 ppm H2O2 7 ppm H2O2 14 ppm H2O2 7 ppm H2O2 14 ppm H2O2

Ch

emic

al L

og

Red

uct

ion

per

Un

it o

f P

ow

er D

raw

UV-OxidationUV-Photolysis

TCE

NDMA

1,4-Dioxane

CONTAMINANT DESTRUCTION BALANCE

EXAMPLES OF ECT CONTAMINANTS

N-nitrosodimethylamine (NDMA)Industrial additive & disinfection byproduct

1,4-DioxaneIndustrial solvent

Pesticides & HerbicidesAgricultural crop protection products

Petroleum AdditivesIncluding MTBE

Volatile Organics (TCE, PCE, Vinyl Chloride, etc.)

Naphthalene and Phenols

Pharmaceuticals & Personal Care ProductsIncludes potential endocrine disruptors

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

• 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

Formula C5H12O

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

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

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

LAMP TECHNOLOGY

MPEE/O = 7.92

LPEE/O = 2.85

2.12

2.14

2.16

2.18

2.2

2.22

2.24

2.26

2.28

2.3

2.32

2.34

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Electrical Energy per Volume (kWh/m3)

Lo

g[H

2O

2]

MP Lamp Baseline Condition LP Lamp Baseline Condition

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

REACTOR DETAILS

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

Two lamp bundles per chamber (one accessed from each end)

Influent Port

Effluent Port

REACTOR DETAILS LPHO

Remediation Case Studies

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

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-dio

xan

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ati

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(p

pb

)

Influent

Reactor #1

Reactor #2

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

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

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1,2,3- 15ppm 1,2,3- Auto 12-18ppm 2,3-18 ppm 1,3-18ppm

Run number and H202 Concentration

1,4

Dio

xa

ne

Lo

g R

ed

uc

tio

n

Guaranteed Log reduction

Actual Log Reduction

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

LOCATION OF CALIFORNIA DOMESTIC WATER CO

The California Domestic

Treatment Facility

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

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

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

NDMA TREATMENT PERFORMANCE CAL DOMESTIC

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05/01/01 05/01/02 05/01/03 04/30/04 04/30/05 04/30/06 04/30/07

Sampling Date

ND

MA

Co

nce

ntr

atio

n (

pp

t)

NDMA, UV Influent

NDMA, UV Effluent

TrojanUVPhox Online

ENERGY USAGE (kWh) CAL DOMESTIC

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50,000

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450,000

05/01/01 05/01/02 05/01/03 04/30/04 04/30/05 04/30/06 04/30/07

Date

Mo

nth

ly k

ilo

wat

t-h

ou

r (k

Wh

) U

sag

e

TrojanUVPhox™ Operational

(April 21, 2005)

• ~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

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

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

Questions?

Terry KeepECT Sales ManagerTrojanUV(519) [email protected]

www.trojanuv.com