A Submerged Attached Growth Bioreactor (SAGB) And Membrane Filtration For Water Reuse

Transcription

1 A Submerged Attached Growth Bioreactor (SAGB) And Membrane Filtration For Water Reuse Philip B. Pedros, Ph.D., P.E. Andrew R. McBrearty, P.E. Wallace W. Bruce

2 Agenda Introduction Description of Process Performance Costs Conclusions

3 Introduction Less land for development around metropolitan areas Concerns regarding available land Undesirable topography Proximity to wetlands or other environmental sensitive areas Lack of public water and/or wastewater

4 Introduction The Jefferson at Bellingham (JPI) impacted by all factors 300 unit, luxury apartment complex on 17 acres 54,000 gpd Development is 3,400 ft. upgradient from public water supplies Effluent to meet Massachusetts reuse standards

5 Introduction Massachusetts DEP Guidelines for Reuse 3 Categories for reuse Spray irrigation Toilet flushing Indirect aquifer recharge Indirect aquifer recharge applied to JPI

6 Introduction The Most stringent discharge limit applied Effluent Characteristic Discharge Limitations BOD 5 10 mg/l Total Suspended Solids 5 mg/l Total Nitrogen 10 mg/l Median Fecal 0 col/100 ml Turbidity 2 NTU Phosphorus limit < 1 mg/l also included

7 Design For biological nutrient removal (BNR) Submerged attached growth bioreactor SAGB For fecal coliform & turbidity Hollow fiber microfiltration

8 Process SAGB - media sumerged in process flow Advantages no separate solids separation process high concentration of viable biomass small reactor volume required to treat a given waste stream

9 Main reactor designed to achieve Process biological oxidation of carbonaceous matter and nitrogen removal solids separation Intermittent aeration Secondary (polishing reactor) Enhanced denitrification Chemical removal of phosphorus

10 Main SAGB Amphidromefinalweb.exe

11 Process Flow Schematic SAGB MF & UV Methanol Aluminum Chlorohydrate Polishing Filter

12 SAGB

13 Dual Reactors - Common Wall Construction 40,000 gpd

14 U-Block Underdrain (under construction) 15,000 to 200,000 gpd

15 U-Block Underdrain (completed)

16 Microfiltration Hollow Fiber Membrane PVDF Flow outside to inside Pore size 0.1 microns

17 Capital Cost Equipment cost Total cost $ 390, $1,350,000.00

18 Performance - Flow Flow (gallons/day) 30,000 25,000 20,000 15,000 10,000 5,000 Average Flow = 16,440 gpd 0 5/28/05 9/5/05 12/14/05 3/24/06 Date 7/2/06 10/10/06 1/18/07

19 Effluent Total Nitrogen (mg/l) Performance - Total N 14.0 Average = 3.6 mg/l Median = 3.45 mg/l May-05 Sep-05 Dec-05 Mar-06 Date Jul-06 Oct-06 Jan-07

20 Performance - BOD Average = 7.2 mg/l Median = 3.9 mg/l Effluent BOD5 (mg/l) May-05 Sep-05 Dec-05 Mar-06 Date Jul-06 Oct-06 Jan-07

21 Performance - BOD Effluent BOD5 (mg/l) 35 BOD5 30 Nitrate mg COD/mgNO3--N = Oct-05 Dec-05 Feb-06 Mar-06 Date May-06 Jul-06 Aug-06

22 Performance Phosphorus Multiple point injection Total P < 1.0 mg/l Molar ratio (Al/P) State relaxed effluent value to < 2 mg/l

23 Performance Weekly fecal coliform tests non detect Quarterly virus tests (Total Virus and MS2-Phage) non detect State removed virus testing

24 Performance - Electrical Power (KW-hrs/day) Dec-05 Average: 207 KW-hrs/day Cost: $684/month $8,325/year Feb-06 Mar-06 May-06 Date Jul-06 Aug-06 Oct-06

25 Power Cost ($/1000 gal.) Performance - Electrical $2.00 $1.50 $1.00 $0.50 Average cost = $1.33/1,000 gallons $ /14/05 3/24/06 7/2/06 Date 10/10/06 1/18/07

26 Annual Operating Cost O&M Electrical Methanol Al Chlorohydrate Total $ 48, $ 8, $ 3, $ 8, $ 67,970.00

27 Conclusions SAGB/MF process effective for low total nitrogen and 0 fecal coliform Intermittent aeration reduces energy consumption Low visual impact of system BNR process underground

28 Conclusions Increase recycle from 1 to 2 or 3 Reduce aeration Reduce methanol

29 Questions Thank you!

30 Comparison of Electrical Cost ($ /1000 gal.) $4.00 $3.50 $3.00 $2.50 $2.00 $1.50 $1.00 MBR $3.27/1,000 gal-day SAGB/MF $1.33/1,000 gal-day MBR SAGB/MF $0.50 $0.00 Dec-05 Feb-06 Mar-06 May-06 Jul-06 Aug-06 Oct-06 Nov-06 Jan-07 Date

31 Biomass 16,000 Biomass Dry Weigh t (mg/l) 13,925 14,040 14,000 12,000 11,508 11,520 10,000 VLAS - High Flow VAS - High Flow 8,513 8,000 VLAS - Medium Flow 6,629 7,265 6,566 5,684 6,000 VAS - Medium Flow VLAS - Low Flow VAS - Low Flow 4,000 1, ,000 1, Dry Weig ht Concetration - VS- (mg/l) Filter Depth (m) Dry mass of biofilm VLAS VAS VSS within interstitial volume was negligible 18,000 16,000 15,374 7,000-15,000 mg/l 14,452 14,000 12,124 12,000 12,531 10,000 9,163 7,660 8,000 7,296 6,039 6,000 7,117 High Flow 4,000 Medium Flow 2,000 Low Flow Filter Depth (m)

32 Design at JPI Bellingham

33 Anoxic Equalization Tank

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