Shining the Light on Chemistry Ultra-low TRC Limit Leads to PAA … · 2019-12-03 · and final TRC...
Transcript of Shining the Light on Chemistry Ultra-low TRC Limit Leads to PAA … · 2019-12-03 · and final TRC...
OBG PRESENTS:
Shining the Light on ChemistryUltra-low TRC Limit Leads to PAA Piloting and Design
Isaac Katz, PE & Bill Meinert, PE | OBG | WaterJAM Conference 2016
AGENDACity of Oneida WWTP
Overview, SPDES
Disinfection Alternatives Study
Cl2, UV, PAA Preliminary Engineering - PAAPAA Piloting
Bench, Full-Scale, Quench IssuesDesign and Implementation
Disinfection Regulations
Q&A2
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City of Oneida WWTP
Discharge to Oneida Creek
Prior TRC Limit2 mg/L
Sodium Metabisulfite Dechlorination
Gaseous Chlorine Disinfection
3.75 MGD
City of Oneida WWTP
CHLORINE ROOM
Oneida Creek
MH10
MH11
CCTs
SMBS
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City of Oneida WWTP SPDES PermitOutfall 001
Constituent Limit
Flow 3.75 MGD Monthly Average (MA)
CBOD5 25 mg/L (MA) / 40 mg/L (7-day average)
TSS 30 (MA) / 45 (7-day Avg)
pH 6.5 – 8.5
NH3-N 7.4 mg/L Winter (11/1-5/31) MA, 3.5 mg/L Summer (6/1-10/31) MA
TP 0.6 mg/L 12-month rolling Avg
DO 7.0 mg/L instantaneous, when Flow > 2.5 MGD (& monitor daily minimum)
Fecal Coliform200 MPN/100mL 30-Day Geometric Mean (GM), 400 MPN/100mL 7-Day GM (seasonal effluent disinfection required 5/15 – 10/15)
TRC0.1 mg/L Daily Max (interim, 36-month from Effective EDP date), 0.02 mg/L Daily Max (final, EDP + 36 months)
Oneida WWTP SPDES Permit
Oneida Creek, Class C
Renewal with interim and final TRC limits
Alternatives analysis following attempts to meet the limit with the existing chlorination –dechlorination
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Previous TRC limit of 2.0 mg/L
Draft SPDES Permit issued November 13, 2013
Interim TRC limit of 0.1 mg/L
Tech. detection level of 0.1-0.5
Final TRC limit of 0.02 mg/L
NYSDEC-defined WQBEL
NYS Water Quality Standards
NYSDEC implementing lower enforcement compliance level or daily maximum limit
Has affected a number of POTWs in NY
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Limit Reduction based on TRC Standard Method 4500-Cl-G
• Practical Quantitation Limit (PQL) = “lowest level that can be reliably achieved …”
▪ Technology-based limit
• 2 mg/L (or, recently 0.5 mg/L)
• Compliance level 0.1-0.5 mg/L
▪ Water quality-based effluent limit (WQBEL)
• As low as 0.005 mg/L
• NYSDEC defined 0.02 mg/L
USEPA-approved TRC Analytical Methods
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Name EPAStandardMethods
Minimum Detectable Conc. & Inferences (2)
Iodometric Direct Method 1 330.3 4500-Cl B1 mg CI/L using starch iodide endpoint, or 0.040 mg CI/L in a 1,000 mL sample and 0.01N Sodium Sulfate used
Iodometric Method IIBack titration either end-point
330.2 4500-Cl CInterferences from oxide forms of manganese and other oxidizing agents
Amperometric Titration, Direct 330.1 4500-Cl DInterference from nitrogen trichloride, chlorine dioxide, chloramines, copper
DPD – Ferrous Titrimetric Method 330.4 4500-Cl F0.018 mg CI/L, normal working detection limitstypically higher
DPD – Colorimetric Method(Spectrophotometric DPD)
330.5 4500-Cl G0.010 mg CI/L, normal working detection limitstypically higher
Electrode (e.g. Orion 97-70 Chlorine Specific Ion)
--- --- 0.2 mg CI/L; 0.01 mg CI/L with blank correction
Key: DPD = N,N-diethyl-p-phenylenediamineYellow highlights are Standard Method recommend WW methods
Notes:(1) Standard Methods for the Examination of Water and Wastewater, 22nd Edition. 2012.
Oneida WWTPChlorination / Dechlorination
Existing facilities –condition assessment, historical performance
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Reclaimed Water System
• Hypochlorite feed• Cloth filtration• Transfer pumping
Outfall 004, < 1.0-MGD to OIN
(golf course irrigation)
Disinfection Alternatives Study
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Alternative Disinfection Study:
Chlorine
PROS CONS
Conventional
Suppliers
Existing
Low cost
Familiarity
Gas safety
Ultra-low TRC requirement
Careful control
Effluent Toxicity
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Alternative Disinfection Study:
Ultraviolet Light
PROS CONS
Multiple applications and manufacturers
No chemicals
No harmful residuals
High capital costs
Increased maintenance and cost
Operator safety
Performance with site specific WW
Unpredictable electrical cost
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Alternative Disinfection Study:
Peracetic Acid (PAA)
PROS CONS
“Low” chemical dose, No DBPs
No quenching required?
Low freezing point, Long shelf life
Ease of implementation
Demand less impacted by fluctuations in BOD, NH3, TSS?
Effective at a wide range of pH and temperatures
Not widely applied in the US
Logistical and market risks with limited manufacturers
EPA approval, need NYS approval
No buried piping, Venting
Requires 304L SSTL piping, pickled, and passivated
Other demands? (Fe, Mn)
What is Peracetic Acid (PAA)?
Chemistry
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Manufacturing
Use: In place of chlorine as bleach or disinfectant
Equilibrium
Characteristics: Colorless, vinegary, 12-15%
As a WW Disinfectant: “relatively insensitive toward TSS when provided enough contact time” … “highly active at low concentrations across wide range of microorganisms” … our Pilot …
In Industry,Now POTWs
Peracetic Acid
Developing a track record
Potential storage and feed configuration
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Preliminary PAA Layout
Chlorine room retrofit
Alternate:Storage room
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Alternative Disinfection Study
Life cycle assessment of alternatives – compelling reason to test out PAA
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Cl2 Technically feasible?
Technically feasible?
Demonstrated elsewherePAA
UV
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PAA Piloting
Piloting Goals
Confirm PAA as an effective disinfectant
Demonstrate no additional degradation to Oneida Creek
Determine compatibility with existing disinfection facilities and operation
Obtain feedback from plant Staff and City employees
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Piloting Protocol
OBG worked with the City of Oneida and the NYSDEC to prepare a piloting protocol
WHO• Engineering: OBG• Sample collection: City of Oneida Staff and OBG• Chemical / equipment provider: Peroxychem
HOW
• Feed PAA at 2 ppm (bench testing)• Disinfectant flow pacing (manual and automatic)• Detailed sample schedule• Maintain a PAA residual below DEC limit of 0.1 mg/L –
quenching with SMBS
WHERE Temporary outdoor staging area next to the CCTs
WHEN
• Four week pilot from early-October – early-November –Chlor / dechlor followed by PAA
• Pilot with PAA to start outside disinfection season (May 15 – Oct 15)
City of Oneida WWTPSampling Schedule
Oneida Creek
MH 10
Sampling ( 9 AM and Noon)Final Clarifier Overflow
MH 11Bacterial Parameters• Fecal Coliform• E. Coli • Enterococcus
Chemical Parameters• PAA Residual – to be 0.1 mg/L!• PAA Degradation• WET Testing
Water Quality Parameters• pH• DO• CBOD5
CCTs
Pump & VFD
PAA Feed Line
SSTL Manifold
PAA Tote
Containment Pallet
CCTs
Piloting Challenges
PROCESS UPSETS
Season – hot and cold air temp
High Industrial Loading• Solids accumulation• High bacteria, TSS and CBOD
Week 1 & 2 – OBG:• Analyzed bacterial data (MH 10)
and residual data in the CCTs at end of Week 1
• Evaluated Piloting equipment• Tested for short circuiting in the
CCTs
• Cleaned the CCTs
PROCESS UPSETS
Week 3 & 4 – process improvement
Continued solids accrual
OBG:• Analyzed Week 3 data
o High bacterial count and very low residual in CCTs
• Increase PAA 2 to 3 ppm• Analyzed Week 4 data
o High bacterial count (MH 10), high residual in CCTs
• Extend Pilot 1.5 weeks and modify sampling schedule
Piloting Challenges
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Piloting Challenges
OBG
PROCESS UPSETSWeek 5 & 6• Analyze data in weeks 3 and 4
o High bacterial count• Increase PAA dose from 3 to 6 ppm• Modify sampling schedule location and frequency
o Sample three times daily (8am, 9am, 12pm)o Sample fecal at Clarifiers, CCT middle, CCT end,
MH 10• Good effluent = good kill
As a WW Disinfectant:“E Coli low resistance to PAA, similarly Fecal Coliform .. Following in susceptibility are Enterococcus, Giardia, Crypto …”
BACTERIAL PROFILE
Final Clarifier – 104,000 CFU
Middle CCT – 50 CFU, PAA Resid = 0.85
End CCT – 1,300 CFU, PAA Resid = 0.19
MH 10 – 35,000 CFU, PAA Resid = meter “low”
Piloting Challenges
Fecal (week 6)
PAA Pilot TSS & Fecal Count (Middle of CCT) PAA Pilot TSS & Fecal Count (MH 10)
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Piloting Challenges
Key Issue – Solids
Recontamination
Solids travel
What would work?
Lessons Learned
Improve mixing
Maintain upstream performance
Keep tanks clean
NYSDEC requested three toxicity tests, performed on the plant effluent
24-hour composite samples, M – W – F, Mid-October and early November
Function of mixing zone ratio but regulator driven
Results see no additional degradation to the receiving water body (oneida creek)?
WET Test
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Design and Implementation
Project Timeline
Draft SPDES
11/13
Disinfection Alternatives Analysis
12/14 08/15
PAA Pilot
10/15 11/15
Chlorine GasConstruction
08/16 10/16?
Upgrades Operational
Fall 2016,or ready for Spring 2017
Revised Design & Schedule
Summary and Plan Going Forward
Remain flexiblePhased approachPlan for fall 2016Longer-term solution
Chlorine gas remaining life?Future bacteria standard?
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Observations
Low limits pose a challenge
Influent can wreak havoc
Lessons
Site-specific needs
Control, high dosages
• No disinfection system would pass
• Surprise! - solids, PAA supply, diurnal variation, control
• PAA showed promise
• Solids, fecal, pH, DO, WETT
• Less reaction time than chlorine
• Industrial pretreatment review• Operator fatigue – upset, pilot• Phased approach may be best• Controls, SMBS improvements• Chlorine, PAA, or both?
• Compliance schedule management• More disinfection, more quench?,
more control will be needed
Disinfection Regulations
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DisinfectionRegulations
Little guidance for new technology
Future regulations
Future bacteria standards?
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OBG | THERE’S A WAY
Questions?Isaac Katz | [email protected] | 484-804-7283
Design Drawings
PAA Pilot pH
PAA Pilot DO
CBOD5
Peaks in CBOD, consistent with peaks in fecal count Due to process upsets
Oneida WWTP Hydraulic Profile and Upstream Treatment Processes
Complications:Significant industrialfloodplain feasibility of alternatives
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City of Oneida WWTP SPDES PermitOutfall 004
Constituent Limit
Flow Monitor (Daily Max)
Nitrates - N 20 mg/L (Daily Max)
Fecal Coliform200 MPN/100mL 30-Day Geometric Mean (GM), 400 MPN/100mL 7-Day GM, 2,400 MPN/100mL Daily Avg, 5,000 MPN/100mL Daily Max Mean
TRC 2.0 mg/L Daily Max, 0.5 mg/L Daily Min
Study: Total Residual Chlorine Compliance
Available technical approaches
Need to evaluate the feasibility of alternatives - measurement, control, technology options
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Chlorination / Dechlorination
upgrades
Facilities, Controls, Automation
Peracetic Acid?
Track Record, Supplier
No TRC, no DBPs, Quench?, Toxicity?, Effectiveness?, Life
Cycle?
UV?
No TRC, no DBPs, Transmittance?,
Effectiveness?, Life Cycle?, Flood?, Iron-
based Coagulant?
PAA Pilot SetupEquipment
Supplied by Peroxychem
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2 PAA chemical totes, 330 gallons each
2 spill containment pallets
1 pump skid including 1 peristaltic pump and VFD, calibration column, catch basin and necessary isolation and pressure relief valves
1 stainless steel manifold, associated suction and discharge piping for the pump
1 SAM unit for PAA residual measurement
We
eks
1-6
We
eks
7-8
Sampling Plan
UV Disinfection
Hydraulics, effluent quality and color, retrofit approach, no chemicals, … floodplain
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Piloting Challenges
CCTs
High residual in middle
Low residual at end of CCTs
FutureRegulations
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Study: Total Residual Chlorine ComplianceSituation, Approach, Solutions?
Developing issue in NY State … different approaches
• Mixing zone analysis, treatment solution
Effluent Disinfection: Gaseous Chlorine, Sodium Metabisulfite
Reclaimed Water System: Hypochlorite, Filtration, Pumping
Solution: … Key Issues
• Attempts to meet with existing
• Feasible alternatives, Control
• Unique WW? Need to pilot?
• Compliance timeline, NYSDEC
Sample Date & Time Fecal Coliform TSS
November 23
12pm – MH 10 15,400 46
November 24
8am – MH 10 1,510 35
9am – MH 10 1,060 24
12pm – MH 10 420 25
November 25
8am – MH 10 800 42
9am – MH 10 1,600 57
Fecal
CCTs High residual in middle Low residual at end of CCTs
END CCTs Solids accumulation at the end of
CCTs Consistently high bacterial count
at MH 10 downstream of CCTs
Piloting Challenges