Evaluating Membrane Fouling Conditions from Demonstration-Scale Under-Ocean Floor Seawater Intake System

Transcription

1 Evaluating Membrane Fouling Conditions from Demonstration-Scale Under-Ocean Floor Seawater Intake System Tai J. Tseng, Jason B. Allen, Yan Zhang, Robert C. Cheng, and Kevin L. Wattier March 30th, Membrane Technology Conference Long Beach, CA 1

2 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 2

3 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 3

4 Seawater Desalination Program A $20 M, 10-year investment Leverage various partnerships for technical input and other support Federal/State/Local Funds, 50% funding by Reclamation Pretreatment Intake/Discharge NF 2 or RO Post treatment / Distribution $5 M Project ($2 M DWR) Prototype UV/ClO 2 Mitigation of WQ impacts due to integration of new source 4

5 Types of Intake Systems Open Ocean Intakes Intakes W/Horizontal Directional Drilling Indirect Intake Beach Well Seabed Filtration Using Buried Pipes (LBWD Approach)

6 Long Beach Method Similar to Fukuoka System Fukuoka, Japan

7 Facility Sites Demonstration Facility Prototype Facility

8 Demonstration Site Layout Area ~2000 ft 2, Discharge rate ( gpm/ft 2 ) Area ~3100 ft 2, Infiltration rate of ( gpm/ft 2 )

9 Cross Section Intake & Discharge

10 Construction

11 View at Low Tide

12 System Layout Underocean Floor (Demo Raw) Wet-well (Filter Effluent) Cartridge Filtration (Filter Effluent +5)

13 Cartridge Filtration

14 Technical Research Objectives Can we sustain water quantity? Determine the maximum sustainable intake filtration and discharge rate What is the water quality and how does it compare to Microfiltration? Microfiltration will be used as the baseline Environmental Impingement/entrainment Federal Clean Water Act, Section 316 (b) Discharge Brine dispersion

15 Research Approach Yield Investigation Investigate Infiltration Rates of 0.05, 0.10, and 0.15 gpm/sf. Water Quality Monitoring Continuous filtrate monitoring Bi-weekly raw, filtrate and post CF microbial monitoring Weekly SDI Intensive 30 day monitoring for tidal impacts

16 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 16

17 Flow through system (June '08- Oct '08, 0.05 gpm/ft 2 )

18 Flow through system (Oct '08- Mar '09, 0.1 gpm/ft 2 )

19 Flow through system (Apr '09- Jun 10, 0.15 gpm/ft 2 )

20 Flow through system (Sep 10- Mar 11, 0.15 gpm/ft 2 )

21 Yield Testing Summary The system can maintain consistent production at 0.05 and 0.10 gpm/sf (design). The system will occasionally shut down on low wetwell level at 0.15 gpm/sf, however, exact combination variables are still unknown.

22 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 22

23 Turbidity Red Tide Event Infiltration Rate, gpm/ft 2

24 SDI 15 Infiltration Rate, gpm/ft 2

25 Enterococci 2,500 Enterococci, cfu/100 ml 2,000 1,500 1, Infiltration Rate, gpm/ft n=33 n=33 n=20 n=138 n=137 n=81 Raw Filtrate Filtrate+5 Raw Filtrate Filtrate+5

26 Infiltration Rate, gpm/ft 2 Marine HPC

27 Special Sampling-Rain Impact Sewer Spill 0.40 inch 0.34 inch 0.44 inch 0.30 inch 3 day cumulative rain 27

28 Special Sampling-Tidal Impact 28

29 Water Quality Summary The system alone can not achieve the desired feed-water quality needed with out additional treatment Cartridge filtration has been added to consistently meet water quality goals No apparent microbial impacts due to tidal events. Microbial levels in raw water spike

30 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 30

31 Membrane Testing 1

32 Membrane Testing 2 32

33 Presentation Outline Project Overview and Approach Demonstration Scale Research and Findings Flow Data Water Quality Membrane Testing Conclusion Initial Findings Future Work 33

34 Initial Findings Water Quantity: The system can produce a sustained water quantity at the tested rates, minor impact observed at 0.15 gpm/sf Water Quality: System can produce water equivalent to Microfiltration effluent Rain event had significant impact on microbial water quality while tide levels have no impact Membrane Testing: <13% increase in pressure after 150 day testing in the pilot membrane unit with no disinfection

35 Future Work Continued testing on current and higher infiltration rates Sand analysis to determine microbe population Additional membrane testing

36 Special Thanks Long Beach Water Department s staff, Cynthia Andrews-Tate, Ana Flores, and Eric Mintz for conducting the laboratory work CA Department of Water Resources and the US Bureau of Reclamation for partial funding of this project Technical Reviewers Dr. Steve Duranceau, Steven Hubbs, and Gary Logsdon

37 Questions 37