Ohio Water

Environment Association

Annual Meeting

June 18-20, 2013

City of Steubenville WWTP

“PAA” Demonstration

PAA Demonstration

The City of Steubenville, Ohio

PAA - What is it and what isn’t it?

-“Fiction and Fact”

Target Pathogens

PAA vs. Chlorine Bleach/Dechlorination

Benefits of PAA

Steubenville PAA Demonstration

SOLVAY Chemicals, Inc.

John Maziuk

Bob Freeborn

John Meakim

Chuck Murphy Assistant Superintendent

City of Steubenville

Wastewater Department

Peroxy-acetic acid –

(aka Peracetic Acid or PAA)

“What it is and what it isn’t”

PAA

Technology Outline

• What Exactly is Peroxyacetic Acid?

• How Does it Differ from Sodium

Hypochlorite Bleach?

• What else is Peroxyacetic Acid (PAA)

currently registered for? – EPA?

What Is Peroxyacetic Acid /PAA

(Proxitane WW-12)

• PAA 12%

• Acetic Acid 15%

• Hydrogen Peroxide 18.5%

H2O2 + CH3COOH CH3COO-OH + H2O

Peracetic acid (PAA) exists in an

equilibrium reaction between

hydrogen peroxide, acetic acid

and water:

O O

II II

CH3COH + H2O2 ↔ CH3COOH + H2O + ΔH Acetic acid Hydrogen Peracetic Acid Water Heat

Peroxide

PAA vs. Chlorine Bleach

PAA Chlorine Bleach -“Green” Product - Carcinogenic/Mutagenic byproducts

-6-10 times lower dosage - High TRC for available “free” chlorine

-100% active, no pH effect below 8.5 - pH dependent, breakpoint concerns

-No need to “deactivate” - may require Dechlorination

-TSS/PAA correlations - TSS/Chlorine effected by other variables

-No effect with ammonia or organics - neutralized by ammonia and organics

-Effective odor control - chlorine residual vapors

-No degradation over time 24 mo. Min - looses concentrations over time

-100% effective up to 140F - breaks down with increased heat

-“Land Use” approved, no effect - oxidizes land and organic materials

-Diluted - No effect on PVC/CPVC - PVC becomes brittle over time

-Economically viable vs. chlor/dechlor - Higher cost with dechlor

PAA

“FICTION AND FACT”

FICTION - PAA IS EXPLOSIVE

FACT – HIGH CONCENTRATIONS (35% AND GREATER) ARE

UNSTABLE AND AT TEMPERATURES ABOVE 55 C CAN

EXPERIENCE “SELF-ACCELERATING DECOMPOSITION”

FICTION – PAA IS CORROSIVE

FACT – IN IT’S “NEAT” FORM, IT IS CORROSIVE. IN PRACTICAL

APPLICATIONS FOR WWTP’S AND CSO’S pH DEPRESSION

IS APPROXIMATELY 0.1 pH UNITS

PAA

“FICTION AND FACT”

FICTION - PAA is “TOXIC”

FACT – YES! IT IS EXTREMELY TOXIC AT LOW CONCENTRATIONS

(0.5-3 PPM) TO PATHOGENS

FICTION – PAA IS TOO EXPENSIVE

FACT –YES. POUND PER POUND VS. CHLORINE/DECHLOR IT IS.

APPLICATION USE AND DOSAGE RANGES FROM 8 – 10 TIMES

LESS MAKING IT MORE THAN COST EFFECTIVE. FEED

AND CONTROL EQUIPMENT COSTS CAN BE ¼ - 1/3 THE COST..

PAA

IS

PAA

TARGET PATHOGENS

Fecal-coliform

E-Coli

Steubenville WWTP

PAA Demonstration

April 1 – 31, 2012

PAA Demonstration

PURPOSE

- To replace chlorine and sodium bisulfite

- Reduce/eliminate THM’s and other chlorine

byproducts

- Be cost effective

- Meet NPDES Permit pathogen limits

- Flow pace chemical feed

- Determine lowest PAA residual to meet

permit

PAA Demonstration

PROCESS

- Switch from Bleach/bisulfite to PAA but able

to turn it back on immediately

- Flow pace feed on North/South total flow

- Establish base feed rate of 1.5 ppm of PAA

- Track residuals every 2 hours on effluent

- Test daily for Fecal levels vs. PAA residuals

- Reduce feed dosages/residuals to meet

permit discharge limits for fecal coliform

PAA Demonstration

PAYOFF

- Lowest PAA minimum feed rate quantified to

meet discharge pathogen levels required to

meet NPDES permit

- Acute “WET” testing at that level “Passed”

- Simplified feed system proposed with online

testing capabilities TBD

- Cost comparisons to Bleach/Dechlorination

favor PAA

PAA Demonstration Results

- PAA feed rate of 0.6-0.7 ppm yielded

discharge residuals of 0.4 ppm

- CBOD remained “constant”, no impact

- Fecal Geomean below NPDES limits when

PAA effluent discharge above 0.4 ppm.

- Complete flow paced PAA feed acceptable

for residual and pathogen control.

- PAA >25% less costly than chlorine and

dechlorination

PAA Trial – March 27 to April 26, 2012

Fecal Coliform vs. PAA Outfall Residual

0.0

200.0

400.0

600.0

800.0

1,000.0

1,200.0

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930

Daily Testing

Fecal

Co

lifo

rm

(CF

U's

/100m

l)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

PA

A R

esid

ual

(pp

m)

Fecal Coliform PAA Residual

Fecal Coliform Deactivation

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

0.25 0.30 0.35 0.40 0.45 0.50 0.55

PAA Residual (ppm)

GE

OM

EA

N F

ecal

Co

lifo

rm

(CF

U's

/100m

l)

Fecal Coliform

Chlorine/Sodium Bisulfite Test Test Period: May 16-31, 2012

Secondary Flows: 4.22 to 6.88 MGD

Liquid Chlorine Usage/Control: 2.75 – 4.56 ppm

67.28 to 111.63 gpd

Liquid Sodium Bisulfite Usage: 100.92 to 162.09 gpd

The test determined a 42% projected savings at these

theoretical feed rates. When comparing the cost per 1000

gallons of treated water for 2011 usage of chlorine and

sodium bisulfite, there was over 25% theoretical reduction in

costs using PAA.

Date Secondary Fecal

(CFU/100ml) Effluent "Summer"

(CFU/100ml) PAA Resid Effluent

(ppm)

5-Jun 3300 56.3 0.53

6-Jun 2500 40.3 0.49

7-Jun 2100 32.7 0.82

11-Jun 900 30 0.49

12-Jun 2500 51.7 0.44

13-Jun 2400 54.3 0.33

14-Jun 2000 70.3 0.32

18-Jun 8400 34.3 0.52

19-Jun 52000 166.7 0.38

21-Jun 31000 86.3 0.42

25-Jun 27000 39.3 0.55

26-Jun 32000 60.3 0.38

27-Jun 21000 67.7 0.45

28-Jun 8800 32.3 0.45

City of Steubenville WWTP

PAA Demonstration (June 2012)

PAA Demonstration

NEXT STEPS……

- Initiate permit modification (Winter 2013)

- Initiate temporary changeover from

Bleach to PAA (Spring 2013)

- Design Bulk feed system and install

- Test on-line residual PAA capabilities

- Conduct Excessive Wet Weather tests

with PAA on overflow