There Is Another Flat Plate MBR

Transcription

1 There Is Another Flat Plate MBR Evaluation of Huber's VRM Membrane Bioreactor Technology Henryk Melcer

2 Background VRM Technology Pilot plant Review of Investigation Preliminary conclusions Outline

3 Membrane Bioreactors Flat plate Hollow fiber Tubular Others Kubota, Toray, Meurer, Westech, Huber

4 Huber VRM Technology

5 Membrane Structure Asymmetric composite membranes Polyether sulfone membrane, 0.38 µm nom pore size Polypropylene carrier material Permeate Mixed liquor

6 Membranes mounted on two sides of backing plate Four plates stacked with defined gaps to make a module Four/six modules assembled into one element Membrane Module

7 Submergence Vacuum Rotating Membrane Concept Permeate discharge Scouring air intake Membrane module Hollow shaft Element/disc

8 Rotation Drive motor Chain Scouring air lines Element/disc

9 Varberg Pilot Project

10 Varberg, Sweden Oslo Stockholm Varberg Copenhagen

11 Bua WWTP AS Package Plant

12 Bua WWTP Discharge

13 Pilot Plant Parameter Total System System model VRM 20/108 Total Flow, gpd - average 9,510 - maximum 17,120 Aeration Tank Membrane Tank Volume, gal 3,700 2,640 Approx. operating depth, ft Membranes Disc diameter, ft 7.15 Disc speed, rpm average 0.9 Membrane area/module, ft No. of modules per disc 6 No. of discs 6 Total membrane area, ft 2 1,163 Flux net lmh (gfd) < 30 (17.4) A M C

14 Instrumentation, SCADA Output Parameter Type Wastewater/permeate BOD, COD, P species, TSS, alkalinity, ph Membrane tank parameters (flow, pressure, ML level) MBR process parameters (temperature, MLSS, ammonia, nitrate) Sample Type Grab On-line On-line Rationale for Collection Provide influent & permeate characteristics to measure loading parameters & system performance Measure membrane performance in terms of flux, TMP and permeability (T-corrected) in real time Provide real time process data

15 SCADA Data Logging

16 Test Objectives VRM previously subject to Title 22 test protocol Av flux 29.3 lmh (17 gfd) Peak flux 56.9 lmh (33 gfd) for 4 hr over 6 days No significant increase in TMP These tests complementary to Title 22: measure performance at Operation at const flux 15.7 lmh (9.1 gfd) at low T Operation during incremental increases in flux rate to 24 lmh (14.1 gfd) Peak flow testing

17 Results

18 Effect of Changing Rest Period: 1 Flux TMP Temp Permeability Doubling time between resting periods from vendor-recommended 240 sec permeation/60 sec rest to 540 sec permeation/60 sec rest

19 Effect of Changing Rest Period: 2 Flux TMP Temp Permeability

20 Effect of Incremental Flux Change - No Rest Temp Flux TMP Permeability Minimal response to step changes in flux w/o interim rest phase until 15 lmh (8.7 gfd)

21 Effect of Incremental Flux Change - with Rest Temp Flux TMP Permeability Slow linear response to step changes in flux with interim rest phase

22 Operation at Long Term Steady- State Flux Flux: 15.7 lmh (9.1 gfd) Temp: C TMP Permeability TMP range = psi

23 Operation at Extended High Flux Rates Flux: 30.4 lmh Temp 35 lmh TMP Permeability

24 Permeate Quality Parameter (mg/l) Influent Permeate BOD <3 COD <30 Ammonia Nitrate TSS <2 Alkalinity (as CaCO 3 ) During test period Dec 16, 2007 June 30, 2008

25 No maintenance cleaning Minimal recovery cleaning Unique air scouring system Membrane Cleaning Spec: 0.25 m 3 /m 2 -hr (1.67 cfm/100 ft 2 ) Rotation: up to 2.5 rpm

26 Power consumption 0.5 kwh/m 3 at fullscale At pilot-scale, measured 2.0 kwh/m 3 Submerged bearings >50 years history with screening technology Filterability Very good: 2-6 mg/l TOC measured in dewatering filtrate Other Engineering Issues

27 Conclusions Permeate BOD & TSS were < detection limits for whole trial Met EEC bathing standards Demonstrated benefit of membrane relaxation No discernable TMP increase observed over 6-wk of operating at constant flux of 15.7 lmh (9.1 gfd) & low influent T of C. Continuous high fluxes of 30 & 35 lmh did not cause dramatic TMP increases nor decline in permeability Operators had favorable experience with VRM for 6- month period

28 Acknowledgements