Goals of Process Analysis. Process Operation of the Winslow WWTP. Initial Operations Analysis. Flow Data from 1/2014 to 3/2015 8/14/2015

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1 Goals of Process Analysis Process Operation of the Winslow WWTP Randal W. Samstag Civil and Sanitary Engineer Bainbridge Island, WA Identify possible operating problems Check capacity Develop basis for potential changes to AB configuration to improve performance Initial Operations Analysis Flow Data from 1/2014 to 3/2015 Looked at operating data from 2014 through March 2015 Developed graphs of operating data Checked Michael Richards studies Final Effluent Flow Effluent Flows NPDES Permit Max Month Design Flow 30 per. Mov. Avg. (Effluent Flows)

2 Loading Data from 1/2014 4/2015 Effluent BOD Influent Loading Inf BOD lbs/d Inf TSS lbs/d NPDES Permit BOD Loading lb/day Max Month Effluent BOD Eff BOD mg/l BOD Removal % 30 per. Mov. Avg. (Eff BOD mg/l) 30 per. Mov. Avg. (BOD Removal %) NPDES Permit TSS Loading lb/day Max Month 30 per. Mov. Avg. (Inf BOD lbs/d) 30 per. Mov. Avg. (Inf TSS lbs/d) ,000 3, , ,500 2,000 Value (mg/l) ,500 1, Effluent TSS Settleability Data from the Sewer Plan Effluent TSS Eff TSS mg/l TSS Removal % 30 per. Mov. Avg. (Eff TSS mg/l) 30 per. Mov. Avg. (TSS Removal %) Value (mg/l) Removal (%) 2

3 Settleability Data from 1/2014 4/2015 Primary Causes of Poor Settleability SVI and SRT SVI ml/gm Typical SVI MCRT days 30 per. Mov. Avg. (SVI ml/gm) Linear (Typical SVI) 30 per. Mov. Avg. (MCRT days) Filamentous Organisms Slime Low floc density SVI (ml/g) MCRT (Days) Michael Richards Filament ID Population Distributions 6/24/2014 8/7/2014 High VFA Type 021N Not branched Immobile Straight Filament length > 200 m No attached growth Little sulfur storage Gram negative Neisser negative Can be improved by anoxic / aerobic selector 3

4 High VFA, Low Loading Type 1851 Low F/M Type 0092 Not branched Immobile Straight Filament length usually > 200 m Usually with attached growth Rectangular cells Gram positive Neisser negative Selector usually effective Not branched Immobile Straight Filament length < 200 m No sulfur storage Gram negative Neisser positive Hidden in flocs Low sludge loading Higher temperatures Selector not always effective Septicity Thiothrix Sulfur-oxidizing aerobe 50 to 200 μm in length, μm diameter extending from floc surface Gram-negative, Neissernegative Intracellular sulfur granules Anaerobic selectors can be counter-productive if SRT < 2.0 days Long SRT (Low F/M) Microthrix Parvicella Coiled growth 50 to 200 m long / 0.8 m wide Gram-positive Neisser-positive granules Encouraged by Alternating aerobic / anoxic conditions Grow in unaerated zones Controlled by PAX SRT 8-50 days Anoxic selectors don t work on them (Can denitrify?) 4

5 Foamers Nocardioforms High VFA Type 0961 True branching No sulfur granules No attached growth Filament length 5 30 m Irregularly shaped Positive Gram stain Neisser negative Anoxic selectors potentially effective Cationic polymers can bring them under control Not branched Immobile Straight Filament length > 200 m No attached growth No sulfur Gram negative Neisser negative Low F/M Type 0675 No branching Immobile Straight Variable length Much attached growth No sulfur storage Gram positive Neisser negative Selectors not always effective Winslow Micro Characteristics Microorganism Foamer? Low Loading High VFA Selector? Type 021N + Yes Type Yes Type Not Always Thiothrix + Anaerobic > 2 days SRT M. Parvicella + + Not anoxic Type ??? Type Not Always Nocardioforms + Potentially 5

6 Max Month Capacity Good Settleability Max Month Capacity Poor Settleability Assumptions: All tanks in service BOD = 350 mg/l Flow Peak Factor = 2.5 Yield = 0.59 lb VSS / lb BOD SRT = 8 days SVI = 150 ml/g Max Month Flow Capacity > 1.2 mgd Assumptions: All tanks in service BOD = 350 mg/l Flow Peak Factor = 2.5 Yield = 0.59 lb VSS / lb BOD SRT = 8 days SVI = 250 ml/g Max Month Flow Capacity < 1.2 mgd Alternatives to Improve Settleability Winslow WWTP BioWin Schematic High septicity filaments not easily controllable except by implementing anaerobic selector Influent Gritand Compactor Returns Compactor Return Screenings W. Grit Tank E. Grit Tank PAX can kill Microthrix Parvicella Split Anaerobic / Anoxic Zones 1 and 2 into unaerated and aerated zones (Carollo) Anaerobic selector: Move IR from first to second stage of AB (Samstag) Grit OF Grit Cyclone Cyclone OF Grit W. Sludge E. Sludge W. An 2 W. An 1 W. Aerobic 1 W. Aerobic 2 W. Aerobic 3 E. An 1 E An 2 E. Aerobic 3 E. Aerobic 2 UV E. Aerobic 1 Effluent to Outfall Dewat Sludge 6

7 Calibration to Dynamic 2015 Data Typical BOD Profile Dynamic Nitrogen Simulation Typical Nitrogen Profile 7

8 Dynamic Phosphorus Simulation Typical Phosphorus Profile Comparison of Performance Split Anoxic/Anaerobic Zones 1 and 2 Winslow WWTP BioWin AB Schematic West Side Split Unaerated / Aerobic Influent Compactor Return W. Grit Tank E. Grit Tank Gritand Compactor Returns Screenings W. Sludge E. Sludge Grit Cyclone Cyclone OF W. Aerobic 2b W. An 2 W. Aerobic 1b W. An 1 E. An 1 E Aerobic 1b E An 2 E. Aerobic2b Grit OF Dewat Sludge Grit E. Aerobic 3 E. Aerobic 2 E. Aerobic 1 W. Aerobic 1 W. Aerobic 2 W. Aerobic 3 UV Effluent to Outfall 8

9 Comparison in BOD Removal Split Anoxic/Aerobic Zones 1 and 2 Comparison in Nitrogen Removal Split Anoxic/Aerobic Zones 1 and 2 Split Zones 1 and 2 Split Zones 1 and 2 Comparison of Phosphorus Profile Split Anoxic/Aerobic Zones 1 and 2 Comparison in Organisms Split Anoxic/Aerobic Zones 1 and 2 Split Zones 1 and 2 Split Zones 1 and 2 9

10 Anaerobic Selector Anaerobic Selector Designed to encourage PAO by providing the right metabolic conditions for their growth PAO are compact Neisserpositive organisms PAO are actually more dense than typical floc PAO take up soluble BOD anaerobically (starving the filaments) Influent Selector Main Basin Clarifier Effluent Anaerobic first stage Encourage PAO and/or GAO SRT days to 5 days No internal recycle required Can encourage Thiothrix if it produces H 2 S PAO need both anaerobic and fully aerobic conditions Anaerobic Selector PAO Phosphorus Accumulating Organisms Winslow WWTP BioWin Schematic Anaerobic Selector / Second Stage Anoxic Selector BOD Main Basin CO 2 + H 2 O Influent Grit andcompactorreturns Compactor Return Screenings W.GritTank E. Grit Tank Storage Storage O 2 Grit Cyclone Cyclone OF W. Sludge E.Sludge W. An 2 W. An 1 E. An 1 E An 2 Glycogen Reducing Power Energy Glycogen Energy Grit OF Grit W.Aerobic 1 W. Aerobic 2 W.Aerobic 3 E. Aerobic 3 E. Aerobic 2 E. Aerobic 1 Dewat Sludge Poly P Poly P Synthesis PO 4 PO 4 UV Effluent to Outfall 10

11 Winslow WWTP BioWin AB Schematic West Side Anaerobic Selector / Second Stage Anoxic Comparison in BOD Removal Anaerobic Selector / Second Stage Anoxic Comparison in Nitrogen Removal Comparison in Phosphorus Removal Anaerobic Selector / Second Stage Anoxic Anaerobic Selector / Second Stage Anoxic 11

12 Comparison in Organisms Anaerobic Selector / Second Stage Anoxic Tentative Conclusions The existing configuration is probably getting very good nitrogen removal, but very little growth of phosphorus accumulating organisms which improve settling. Splitting Anaerobic / Anoxic Zones 1 and 2 into unaerated and aerobic zones offers no improvement Creating an anaerobic selector by moving the IR from the first to the second AB tank decreases nitrogen removal, but improves biological phosphorus organism growth. This should improve settleability (lower SVI) and increase capacity. Continue to identify filaments to determine type. If Microthrix Parvicella persists, consider PAX. Questions? Randal W. Samstag Civil and Sanitary Engineer randal.samstag@rsamstag.com Web Site: Phone: (206)