Septage Treatment at Small Wastewater Treatment Plants

Transcription

1 Septage Treatment at Small Wastewater Treatment Plants Khamis Al-Omari Omari,, Hazen and Sawyer, P.C MWEA Annual Conference (Session 3) Boyne Mountain Resort Boyne Falls, Michigan June 23, 2008

2 Acknowledgements Stephen May, Lenawee County Drain Commissioner Michael Roys,, Lenawee County Drain Commission W. James Gellner,, Hazen and Sawyer, P.C. Michigan Water Environment Association

3 Objectives Present Project Background Review Regulatory Requirements Present Innovative Concepts Evaluated for Septage Treatment Summarize Full-scale Pilot Program Protocol for Septage Co-digestion with WAS Present Pilot Program Results Conclusions

4 Project Background Existing Plants with Limited/No Capacity mgd Central Lenawee WWTP mgd Rollin-Woodstock WWTP 17,000 Septic Tanks in Lenawee County Annually - Approximately 1.75 Million Gallons of Pumped Septage Applied to Land No Septage Treatment Facilities in Lenawee County Existing Law on Septage Hauling and Disposal Amended in October 2004

5 Septage Design Data (20-year Projection ) 19,900 Septic Tanks Peak Day 33,500 gals Average Day 13,500 gals Maximum Month 18,000 gals/day

6 Amended Law Requirements Septage Haulers Required to Dispose Septage at A Receiving Facility, when: - Septage is Pumped within 15 miles of Receiving Facility (Beginning 10/12/2005) - Septage is Pumped within 25 miles of Receiving Facility (Beginning 10/12/2010)

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9 Amended Law Requirements (cont d) Domestic Septage is Required to be Screened before Land Application (Beginning 10/12/2006) Provide 50,000 gal. or more of Storage Septage Waste will Not be Allowed to be Applied to Frozen Ground (Beginning 10/12/2006)

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14 Domestic Septage Septage Pumped from: - Home Septic Tanks, - Recreational Vehicles, - Cesspool, - Portable Toilet, - Type III Marine Sanitation Device, or - Similar Storage or Treatment Works that receive only Domestic Sewage

15 Central Lenawee WWTP 0.4 mgd Sequential Batch Reactor (SBR) Aerobic Digestion of WAS No Capacity for Septage Expansion to 1.7 mgd

16 Rollin-Woodstock WWTP 1.2 mgd Activated Sludge No Primary Aerobic Digestion of WAS Limited Capacity for Septage Expansion to 2.9 mgd

17 Optimization and Upgrade Alternatives

18 Recommendation Accept and Screen Septage at Rollin- Woodstock WWTP Treat Septage through Solids Handling Process Implement a 90-day, Full-Scale Septage Pilot Program to Provide: - Data on Septage Characteristics - Basis for Upgrades Design - Basis for Optimum Operation - Interim Alternative for Accepting Septage and Meet the Regulatory Deadlines

19 Treatment Concepts Co-digestion of Screened Septage and Thickened Waste Activated Sludge (WAS) Contact Stabilization of Screened Septage Packaged Membrane Bioreactor System (MBR)

20 Recommended Concept: Co-digestion of Screened Septage and WAS

21 Pilot Program: Co-digestion of Screened Septage and Thickened WAS

22 Rollin-Woodstock WWTP Septage Pilot Program Manually Cleaned Screen with 3/8 Spacing Used Two Existing Aerobic Digesters (Total Vol. 103,400 gallons)

23 Septage and Decant Sampling and Analysis Total Solids (TS) Total Suspended Solids (TSS) Volatile Suspended Solids (VSS) 5-Day Biochemical Oxygen Demand (BOD5) Soluble BOD5 Total Kjeldahl Nitrogen (TKN) Ammonia Nitrogen (NH3-N) N) Total Phosphorus (Total-P) Orthophosphate (PO4-P) P) Total Alkalinity ph

24 Raw Septage Volume Raw Septage Characteristics Volume (Gallons) Avg. Volume (gallons), 5, /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day Volume Avg. Volume (gallons)

25 Raw Septage BOD5 & Sol. BOD5 Raw Septage Characteristics Concentration (mg/l) Avg BOD5 (mg/l), 3,916 Avg SOL BOD (mg/l), 234 9/15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day BOD 5 Avg BOD5 (mg/l) SOL BOD Avg SOL BOD (mg/l)

26 Aerobic Digester BOD5 & Sol. BOD5 Decant Characteristics 40 Concentration (mg/l) Avg. BOD 5 (mg/l), 9.8 Avg.Sol BOD5 (mg/l), /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day BOD 5 Avg. BOD 5 (mg/l) Sol BOD5 Avg.Sol BOD5 (mg/l)

27 BOD5 Loadings: Septage vs. Decant BOD 5 Loading (PPD) BOD 5 Loading (PPD) BOD5 Capacity (PPD), 1, /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day Influent BOD5 Septage BOD5 Decant BOD5 BOD5 Capacity (PPD)

28 Raw Septage TSS & VSS Raw Septage Characteristics Concentration (mg/l) Avg TSS (mg/l), 14, Avg VSS (mg/l), 9, /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day TSS Avg TSS (mg/l) VSS Avg VSS (mg/l)

29 Aerobic Digester TSS & VSS Decant Characteristics Concentration (mg/l) Avg. VSS (mg/l), 16.1 Avg. TSS (mg/l), /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day TSS Avg. TSS (mg/l) VSS Avg. VSS (mg/l)

30 TSS Loadings: Septage vs. Decant TSS Loading (PPD) 2000 TSS Loading (PPD) TSS Capacity (PPD), 1, /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day Influent TSS Septage TSS Decant TSS TSS Capacity (PPD)

31 Total Solids in Digesters Total Solids in Digesters Concentration of Total Solids in Digesters 10/1 10/8 10/15 10/22 10/29 11/5 11/12 11/19 11/26 12/3 12/10 12/17 12/24 12/31 1/7 1/14 1/21 Day Digester 1 Digester 2 % Total Solids

32 1/ Total Volatile Solids in Digesters Total Volatile Solids in Digesters % Volatile Solids in Digesters 10/8 10/15 10/22 10/29 11/5 11/12 11/19 11/26 12/3 12/10 12/17 12/24 12/31 1/7 1/14 1/21 Day Digester 1 Digester 2 10/1 % Volatile Solids

33 Cum. VSout, pounds Volatile Solids Reduction (Best-fit Line Analysis) 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Cumulative VSSin (Septage & WAS) versus Cumulative VSout (Decant VSS & Wasted VS) 74% Reduction in Volatile Solids 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 Cum. VSSin, pounds VSS/VS Data Best Fit Line

34 Conclusions Aerobic Co-digestion of Screened Septage and Thickened WAS could: - Reduce Burden of Expanding Liquid Stream - Interim Alternative for Accepting Septage - Significant Reduction in Organic Loading on the Liquid Stream - Reduction of Volatile Solids - No Adverse Impact on Quality of Biosolids Produced

35 Hauled Sludge Vendor Results (Before and After Accepting Septage) 292,000 gal hauled Oct. 323,000 gal hauled Sept. 31, 2006 (before) 20, 2007 (after 12 months) Total Solids 3.0% Total Solids 2.75% Total Volatile Solids 51% Total Volatile Solids 58% TKN-N N mg/kg-dry TKN-N N mg/kg-dry Total-P P mg/kg-dry Total-P P mg/kg-dry ph 7.6 ph 7.0

36 Hauled Sludge Plant Results (Before and After Accepting Septage) 292,000 gal hauled Oct. 31, 2006 (before) Total Solids 3.7% Total Volatile Solids 49% ph 7.2 Pathogen Reduction 9995 cfu/gm 323,000 gal hauled Sept. 20, 2007 (after) Total Solids 5.3% Total Volatile Solids 54% ph n/a Pathogen Reduction 8153 cfu/gm

37 Questions?

38 Misc. Backup Slides for Q&A Only

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46 Rollin-Woodstock WWTP

47 How Septic Tanks Work?

48 Raw Septage NH3 & TKN Raw Septage Characteristics Concentration (mg/l) Avg TKN (mg/l), Avg NH3 (mg/l), /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day TKN Avg TKN (mg/l) NH3 Avg NH3 (mg/l)

49 Aerobic Digester Decant NH3 & TKN Decant Characteristics 12 Concentration (mg/l) Avg. NH3 (mg/l), 0.5 Avg. TKN (mg/l), /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day TKN Avg. TKN (mg/l) NH3 Avg. NH3 (mg/l)

50 Raw Septage Total-P P & Ortho-P Raw Septage Characteristics Concentration (mg/l) Avg Total P (mg/l), Avg Ortho P (mg/l), /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day Total P Avg Total P (mg/l) Ortho P Avg Ortho P (mg/l)

51 Aerobic Digester Decant Total-P P & Ortho-P 3 Decant Characteristics Concentration (mg/l) Avg. Total P (mg/l), 0.9 Avg. Ortho P (mg/l), /15 10/5 10/25 11/14 12/4 12/24 1/13 2/2 2/22 Day Total P Avg. Total P (mg/l) Ortho P Avg. Ortho P (mg/l)

52 Raw Septage TS Raw Septage Characteristics 6 Percentage (%) Average TS (%), /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day Total Solids Average TS (%)

53 Raw Septage Total Alkalinity Raw Septage Characteristics Concentration (mg/l) Avg.Total Alk. (mg/l), 1, /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day Total Alkalinity Avg.Total Alk. (mg/l)

54 Raw Septage ph Raw Septage Characteristics ph Avg ph, /20 10/10 10/30 11/19 12/9 12/29 1/18 2/7 Day ph Avg ph

55 Project Schedule Item Due Date Public Hearing Notice 5/27/2006 Public Hearing 6/27/2006 Project Plan Submittal 7/1/2006 MDEQ Project Priority List 10/1/2006 Final Design to MDEQ 3/1/2007 Bid Advertisement 3/31/2007 Construction Startup 5/1/2007 Construction Completion 10/1/2008