PERFORMANCE AND RESIDUAL MANAGEMENT ASSESSMENT OF 5 MGD MEMBRANE WATER PLANT. Presented by: Stephen P. Dorman, P.E.

Transcription

1 PERFORMANCE AND RESIDUAL MANAGEMENT ASSESSMENT OF 5 MGD MEMBRANE WATER PLANT Presented by: Stephen P. Dorman, P.E. sdorman@ksaeng.com 1

2 Outline Background Assessment of: Clarification Filtration Residuals Summary 2

3 Section 1 BACKGROUND 3

4 Background Location: City of Marlin Source Water: Constructed Reservoir (1950) in Central Texas (Lake Marlin) Original Capacity: 2.5 MGD SWTP Original Units: Rapid Mix, Upflow Clarifiers, Dual-Media Filters, Chloramines Disinfection Improvements: Expand capacity to 5 MGD; Install Pressure Membrane Filters Via Ultrafiltration 4

5 Original Filter Abandoned as part of 2009 Improvements 5

6 Original Filters Pipe Gallery Abandoned as part of 2009 Improvements 6

7 Original Turbidity Results Max Raw Max Settled Max Finished Month Water NTU Water NTU Water NTU Jul <1 Aug Sep Oct <1 Nov <1 Dec <1 Jan <1 Feb <1 Mar <1 Apr May Jun

8 Ultrafiltration Membranes Information Provides physical barrier to particles Size exclusion If particle > 0.1 micron, rejected Pore size is highly uniform, providing absolute removal of targeted particle size or microorganism Repeatability 8

9 Ultrafiltration Membranes Expected Results Turbidity < 0.1 NTU independent of feed water (current standard=0.3) Giardia Cyst and Cryptosporidium Removal is >4 Log (or 99.99%) Virus Removal is >3 Log (or 99.9%) - Piloted Prior to Full Scale Implementation 9

10 Turbidity (NTU) Stage 2 Pilot Test Results Raw, Settled, Permeate Turbidity Raw to Settled Average NTU Reduction=84% Settled to Permeate Average NTU Reduction=98% Raw Water Turbidity Settled Water Turbidity Permeate Turbidity 0 7/1/2006 7/6/2006 7/11/2006 7/16/2006 7/21/2006 7/26/2006 7/31/2006 8/5/2006 8/10/

11 Turbidity (NTU) Pilot Test - Permeate Turbidity /2/06 7/3/06 7/4/06 7/5/06 7/6/06 7/7/06 7/8/06 7/9/06 7/10/06 7/11/06 7/12/06 7/13/06 7/14/06 7/15/06 7/16/06 7/17/06 11

12 Final Plant Schematic 12

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15 Section 2 CLARIFICATION ASSESSMENT 15

16 Original Clarifiers - Upflow Clarifier No. 2 Retained for Pre-Treatment prior to membrane filters. 16

17 Coagulant Dose and Settled Water Raw Flow (MGD) Turbidity Reduction Coagulant Dose (mg/l) Raw Water NTU Settled Water NTU Finished/ Permeate NTU % Remove Raw to Settled % Remove Settled to Finish % Remove Raw to Finish Time Average % 97% 99.61% Minimum % 76% 97.00% Maximum % 99% 99.97% Std Dev % 3% 0.35% Avg+1.73*SD % 101% % 2010 Average % 96% 99.47% Minimum % 76% 97.00% Maximum % 99% 99.87% Std Dev % 3% 0.38% Avg+1.73*SD % 101% % 2011 Average % 98% 99.62% Minimum % 82% 97.00% Maximum % 99% 99.97% Std Dev % 1% 0.34% Avg+1.73*SD % 100% % 17

18 Turbidity (NTU) Coagulant Does (mg/l) Turbidity and Coagulant Dose 250 Coagulant Dose (mg/l) Raw Water NTU Settled Water NTU Permeate NTU /01/10 04/11/10 07/20/10 10/28/10 02/05/11 05/16/11 08/24/

19 Turbidity (NTU) Coagulant Does (mg/l) 2010 Turbidity and Coagulant Dose Coagulant Dose (mg/l) Raw Water NTU Settled Water NTU Permeate NTU /01/10 02/20/10 04/11/10 05/31/10 07/20/10 09/08/10 10/28/10 12/17/

20 TOC Reduction - Summary Actual Date Raw Water Alkalinity Raw TOC Settled TOC % TOC Removed Average Required TOC Removal Minimum Maximum Std Dev Avg+1.73*SD

21 Section 3 FILTRATION ASSESSMENT 21

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23 Ultrafiltration Membrane Skids Skids 100 and

24 Factors Impacting Performance Membrane fouling occurs when contaminants accumulate on the membrane surface over time. Generally speaking, the rate at which fouling occurs is mostly related to the quality of the feed water (i.e., concentration of suspended solids, organics, etc). Membrane compaction occurs due to compression under the pressurized feed water during operation. The extent to which the membranes compact usually depends on the type of membrane filter. Most of the effects of compaction are limited to the first 100 hours of operation. 24

25 Factors Impacting Performance(Cont d) Membrane degradation can occur due to normal wear and tear over time or by exceeding the specified operational limits of the membrane filters. The membrane filters used by the City of Marlin have a maximum transmembrane pressure of 35 psi, allowable ph tolerance range of 1.5 to 13 during cleaning, and a maximum instantaneous chlorine tolerance of 200 ppm at >10.5 ph. 25

26 12/25/09 12/29/09 1/2/10 1/6/10 1/10/10 1/14/10 1/18/10 1/22/10 1/26/10 1/30/10 2/3/10 2/7/10 2/11/10 2/15/10 2/19/10 2/23/10 2/27/10 3/3/10 3/7/10 3/11/10 3/15/10 3/19/10 3/23/10 3/27/10 3/31/10 4/4/10 4/8/10 4/12/10 4/16/10 4/20/10 4/24/10 4/28/10 5/2/10 5/6/10 5/10/10 5/14/10 5/18/10 5/22/10 5/26/10 5/30/10 6/3/10 6/7/10 6/11/10 6/15/10 6/19/10 6/23/10 6/27/10 Permeate Flow (GPM) TMP (PSI) 2010 Permeate & TMP -Stage 200 CITY OF MARLIN-STAGE 200 KOCH MEMBRANE SYSTEMS MGD MGD MGD Permeate Flow TMP 26

27 Permeate Flow (GPM) TMP (PSI) Permeate & TMP for Stage 100 CITY OF MARLIN-STAGE KOCH MEMBRANE SYSTEMS /12/12 12/13/11 11/13/11 10/14/11 9/14/11 8/15/11 7/16/11 6/16/11 5/17/11 4/17/11 3/18/11 2/16/11 1/17/11 12/18/10 11/18/10 10/19/10 9/19/10 8/20/10 7/21/10 6/21/10 5/22/10 4/22/10 3/23/10 2/21/10 1/22/10 12/23/09 11/23/09 Permeate Flow TMP 27

28 Permeate Flow (GPM) TMP (PSI) Permeate & TMP for Stage 200 CITY OF MARLIN-STAGE KOCH MEMBRANE SYSTEMS /13/11 11/13/11 10/14/11 9/14/11 8/15/11 7/16/11 6/16/11 5/17/11 4/17/11 3/18/11 2/16/11 1/17/11 12/18/10 11/18/10 10/19/10 9/19/10 8/20/10 7/21/10 6/21/10 5/22/10 4/22/10 3/23/10 2/21/10 1/22/10 12/23/09 11/23/09 Permeate Flow TMP 28

29 Specific Flux at 20 Deg C (GFD/PSI) Specific Flux Stage CITY OF MARLIN-STAGE /14/09 1/22/10 5/2/10 8/10/10 11/18/10 2/26/11 6/6/11 9/14/11 12/23/11 4/1/12 Stage 100 Specific Flux 29

30 Specific Flux at 20 Deg C (GFD/PSI) 30.0 Specific Flux Stage 200 CITY OF MARLIN-STAGE /14/09 1/22/10 5/2/10 8/10/10 11/18/10 2/26/11 6/6/11 9/14/11 12/23/11 Stage 200 Specific Flux 30

31 Flow (MGD) Recovery 2010 average daily recovery = 87% 2011 average daily recovery = 91% average daily recovery = 89% Raw Water Pumpage (MGD) 0.80 Treated Water Pumpage (MGD) /01/10 04/11/10 07/20/10 10/28/10 02/05/11 05/16/11 08/24/11 31

32 Filters - Recommendations > Turbidity results in > TMP; increase cleaning and backflush cycles with higher NTU. Change backflush cycle to 45 minute cycle with NTU like 2010, and 30 minutes when turbidities are similar to Due to the rise in TMP and flux, the City increased the CIP frequency to 2 / month. With more typical raw and settled water turbidities, return frequency to 1 / month. 32

33 Filters Recommendations(Cont d) Perform overnight soak with citric acid (reduce TMP). Modify SCADA system program to automate reporting process. The number of fiber breakage is within expected occurrences; therefore, no changes are required as a result of fiber breakage. The majority of operation includes 2 skids. When the flow is < 1.2 MGD, only one skid should be utilized to remain within operational parameters. 33

34 Section 4 RESIDUALS ASSESSMENT 34

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36 Treated Water (gpd) Sludge Flow (gpd) 2,500,000 Sludge Management 1,250,000 2,000,000 1,000,000 1,500, ,000 1,000, , , , /01/10 04/11/10 07/20/10 10/28/10 02/05/11 05/16/11 08/24/

37 Treated Water (gpd) Backwash Flow (gpd) 2,500,000 Backwash Recovery 200, ,000 2,000, , ,000 1,500, , ,000 1,000,000 80,000 60, ,000 40,000 20, /01/10 04/11/10 07/20/10 10/28/10 02/05/11 05/16/11 08/24/

38 Residuals - Recommendations Sludge: For the land application area, record and retain all sludge records in accordance with sludge land application registration. Increase frequency of data collection to once per month of sludge volume (to and from thickener, processed by centrifuge, and land applied), percent solids (from centrifuge and to land application), disposal area (per grid), and soil testing for land application area needed in the future. Update crop management plan based on current use of the land. 38

39 Residuals Recommendations (Cont d) Ensure all CIP discharge water enters the Neutralization Tank to neutralize ph before discharge to the waste lift station. Operate the centrifuge once every 10 days to ensure the system remains in good condition for use when flows increase in the future. 39

40 Section 5 SUMMARY 40

41 Summary Clarification - The results showed that the expected removal efficiencies were achieved and only minor modification to coagulant feed was recommended. Ultrafiltration membranes - Operational changes are recommended that will positively impact transmembrane pressure, flux, and turbidity. The city should establish an escrow account to fund future membrane cartridge replacements. Residual management - The results included minor operational changes and increased data collection to be used in future assessments. 41

42 Future Assessment Needs Electrical usage at the plant - various seasons / raw water Staff requirements to fully operate and maintain the plant Outsourcing of membrane / electrical controls maintenance Service life of membranes vs. original life expectancy Total actual operational cost per gallon of treated water with comparison to other similar sized plants Options to reduce seasonal taste and odor Investigate source of rust and scaling found in the last annual inspection of the ground storage tank 42

43 City of Marlin Acknowledgements William McDonald, City Manager James Glenn, Water Treatment Supervisor Koch Membrane Systems Paul Lambert 43

44 CONTACT INFORMATION Stephen P. Dorman, P.E. 44