Passive Membrane Filtration for Small Communities

Transcription

1 Passive Membrane Filtration for Small Communities Patricia A. Oka, MASc. Candidate Pierre Bérubé, PhD, PEng UBC Faculty of Applied Science

2 Boil water advisory

3 Challenges: Goals: Advanced Poor water Treatment quality Cost Lack of effective financial resources Simple Inadequate operation technical information Low Limited maintenance skilled operators Faculty of Applied Science 2/13

4 Positives CURRENTLY NOT SUITABLE FOR SMALL COMMUNITIES! Advanced water treatment Complex 4-log removal (99.99%) of virus, bacteria, colloids, particles Requires skilled technicians High throughput/m 2 footprint Energy intensive Robust Faculty of Applied Science 3/13

5 Peter-Varbanets et al. 2010, Boulestreau et al External membrane system Stable flat sheet membrane operation Gravity driven at mbar. Strictly permeation Reasons for the steady state: Reduced particle mass transfer toward membrane Fouling does not occur at sub-critical flux Existence of biological community Faculty of Applied Science 4/13

6 Through: 1. Gravity permeation of submerged system? ie. Submerged Vs External 2. Reduced dependency of fibre membranes on fouling controls (ie. backwash and aeration)? Faculty of Applied Science 5/13

7 1. Backwash Elimination 2. Permeate Pump Elimination 3. Aeration Elimination Laboratory Testing t = 2-3 months/condition 6-7 ppm DOC surface water Faculty of Applied Science 6/ um UF 7 July 22, 2012 Footer text here

8 Rt/R0 Rt/R0 Are there any benefits in having a periodic backwash in a low-flux SHFUF operation such as at 10, 20, and 30 LMH? Backwash can be eliminated at 10 LMH! LMH LMH R1 No R1 R1 B/W No No B/W B/W R2 Before R2 R2 Before Before B/W B/W B/W R2 After R2 R2 After After B/W B/W B/W Volume 40.0 Filtered (L) Volume Filtered (L) Volume Filtered (L) Faculty of Applied Science 7/13

9 A. Can system simplification be achieved and maintained long-term through gravity permeation? Yes, Indeed! B. Can the system steady-state be achieved at 10 LMH < flux < 20 LMH? Yes, but most stable at 10 LMH. Faculty of Applied Science 8/13

10 Can further system optimization be achieved through reduced aeration conditions? In a ie. system A. 25 with mins no off/ backwash, 5 mins on continuous aeration gives most stable condition. However, a reduced B. aeration 4 hrs off/ system 5 mins is on workable if compensated with more membranes. C. 4 hrs off/ 30 mins on D. Zero Aeration 25 mins off 5 mins on Faculty of Applied Science 9/13

11 Eliminated Item Savings Cost 1. Backwash Power (minimal) Capital (high) 50 LMH 10 LMH 2. Permeate Pump Power (minimal) Capital (high) 10 LMH 10 LMH 3. Aeration Power (high) Capital (minimal) 10 LMH 2 LMH 10/13 11 July 22, 2012 Footer text here

12 IC-IMPACTS Prof. Pierre Berube Paula Parkinson Tim Ma Jason Leong Faculty of Applied Science 11/13

13 Res EAU-WaterNET: Fresh water monitoring: Boulestreau, M., Hoa, E., Peter-Verbanets, M., Pronk, W., Rajagopaul, R., Lesjean, B., Operation of gravitydriven ultrafiltration prototype for decentralised water supply. Desalination and Water Treatment 42, doi: / Peter-Varbanets, M., Hammes, F., Vital, M., Pronk, W., Stabilization of flux during dead-end ultra-low pressure ultrafiltration. Water research 44, doi: /j.watres Peter-Varbanets, M., Margot, J., Traber, J., Pronk, W., Mechanisms of membrane fouling during ultra-low pressure ultrafiltration. Journal of Membrane Science 377, doi: /j.memsci Faculty of Applied Science 12/13

14 Thank you contact info:

15 Development and testing of the field prototype. Further investigation on the biological activity that occurs on the membrane during ultra-low pressure filtration. Faculty of Applied Science 13/14

16 Membrane Properties 16 July 22, 2012 Footer text here

17 Design Calculations

18 Permeate Parameters Descriptions Epoxy 'Active' Fibres Epoxy 40 mm 430 mm 40 mm Filtrate weight Operating flux Temperature TMP correction Membrane resistance and TMP permeability Analyses DOC-TOC HPLC TSS-VSS CLSM Descriptions Reactor and feed water monitoring Level of treatment analysis Biomass growth analysis Biomass quantification on membrane 6.35 mm OD

19 19 July 22, 2012 Footer text here

20 Operation Flux (J OP ) (LMH) : S1&2 - Continuous Air S3 - OFF Air Air Flowrate (ml/min) : 3800 Vs. 0 Dual bulk-cross flow (m/s) : 0.2 Vs. 0 Critical Flux (J CR (LMH) 98.1±2.8 Vs ± 1.29 (Berube et al. 2007) Flux Index (LMH) : -88 to -68 Vs. -16 to 5 Flux index = J OP - J CR Faculty of Applied Science 14/22

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