Hollywood Chemical Injection Facility

Transcription

1 Design and Cost Benefits of the Hollywood Chemical Injection Facility To Dose or Not to Overdose That s the Million-Dollar Question! Kevin Dour, PE, PMP

2 Agenda System overview Sampling and monitoring Modeling recommendations Design Facility siting System performance Lessons learned

3 Brightwater Conveyance System

4 Goals: No odors at the property line; Minimize corrosion

5 Sampling and Monitoring Study Previous KC field inspection identify corrosion Targeted purpose: identify odor and corrosion issues upstream of Brightwater (interceptors and structures) Field data collection Monitor H 2 S with Odaloggers Grab sample Dissolved sulfides, dissolved oxygen, temp, ph, BOD Sulfide prediction model Used to estimate dissolved sulfides in new Brightwater System. Pomeroy and Parkhurst equations Calibrated using representative data from the sampling and monitoring study

6 Sulfide Prediction Model ppd of dissolved sulfides - 60% sulfides generated in SVI

7 Sampling and Monitoring Study Recommendations Siting facilities Design concentrations Chemical usage (Bioxide TM ) Hollywood Pump Station: Install chemical injection Continue to monitor corrosion along SVI & BWI Design for inlet dissolved sulfide concentration of 1.5 mg/l at Hollywood

8 Sulfide Prevention Sulfate-Reducing bacteria (SRB) forms sulfides from sulfates in the absence of oxygen Bioxide TM Calcium nitrate NFPA rating: Heath-1, Fire-0, Reactivity-0 Does not degrade Does not require freeze protection Prevents & removes sulfides Interrupts SRB s sulfate respiration Cultivates sulfide oxidizing bacteria

9 Hollywood Chemical Injection - Design Address existing and future odor and corrosion problem Reduce downstream DS and H 2 S Corrosion protection in existing system Chemical injection system Dosage: 3.4 gallons Bioxide/lb dissolved sulfides mg/l peak dissolved sulfides 4,400 gallon storage tank Diaphragm metering pumps Flow paced off Hollywood effluent flows Pacing constant to adjust dosing to respond to high sulfides in the system

10 Hollywood Chemical Injection - Design Existing pump station site Tight access Within shoreline/wetland setbacks Other facilities improvements: Generator Gate/flow modifications in Hollywood & York Diversion Structures I&C upgrades/brightwater

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12 Access Drive Pump Station from Trail Trail from Pump Station Wetland from Property Line

13 Chemical Metering Pumps Chemical Fill Port Containment Area/ Emergency Eyewash BioxideTank

14 Downstream Benefits Interceptor Protection Reduce dissolved sulfides in SVI Reduce downstream H 2 S release at Woodinville PS and BWI Control future corrosion in BWI and SVI Balance cost of Bioxide TM usage with intended benefits Prevent chemical overdosing Monitoring important

15 Downstream Benefits North Creek Odor Control Facility Facility upgraded prior to Brightwater going on line Complex flow management impacts odor generation Existing carbon scrubber odor control system New biological scrubber installed

16 System Performance Monitor chemical injection performance Downstream H 2 S monitoring to assess chemical injection performance Chemical dosing goal: Maintain 0.1 mg/l nitrates in SVI (no dissolved sulfides) Dissolved sulfides zero at North Creek Nitrate residual analyzers Limited reading measurements

17 System Performance Vapor phase treatment + chemical injection = symbiotic performance Conducted H 2 S monitoring at North Creek to assess upstream chemical injection in June & August 08 upstream chemical injection in June & August 08 Average H 2 S reduced over 80% with chemical injection Peak H 2 S reduced almost 60% with chemical injection Bioscrubber: Lower and less variable inlet H 2 S concentrations Higher level of performance expected

18 No Chemical Injection (June 08) - Average H 2 S = 6.5 ppm - Peak H 2 S = 24.7 ppm *Preliminary H 2 S monitoring at North Creek Diversion Structure With Chemical Injection (Aug 08) - Average H 2 S = 0.8 ppm - Peak H 2 S = 10.0 ppm

19 Lessons Learned Sampling and monitoring essential to siting and sizing odor/corrosion facilities Chemical injection facility Chemical delivery access Operation and control Lifecycle costs ($/gal, delivery costs) North Creek bioscrubber Biological systems performance varies based on temperature, and inlet H 2 S (intermittent vs. continuous) Consider future performance testing by varying upstream chemical doses A symbiotic approach to odor control increases efficiency and reliability!

20 Questions?