Operating Data Comparison for Treatment Technology Transition
OBG PRESENTS: Operating Data Comparison for Treatment Technology Transition from SBR to MBR with Effluent Polishing Authors: Danielle Popov, Frank DeOrio, Ephraim Schayek, Maria Scicchitano, Mark Sposato AGENDA Background Sequencing Batch Reactor Membrane Biological Reactor Technology Transition MBR Start-Up Observations Operational Comparison of SBR/RO and MBR/RO Conclusions
2 Parameter Effluent Limit
BOD5 400 mg/L
Background TKN 150 lbs/d
TSS 600 mg/L
UV-T 65%
Landfill with on-site biological leachate treatment
Age: 25+ years
Parameters of interest for treatment: BOD5/COD, Ammonia, TDS, TSS, and UV-T interfering compounds
Design and permit limits
3 BACKGROUND . Future Outlook: need to prepare for treatment expansion • Increased treatment capacity 130K GPD to 289K GPD • Changing landfill characteristics with time
. Mitigate performance risk of increased strength and variability of influent parameters . Incorporation of additional sources of wastewater streams
. Utilize limited footprint
. Improve feed quality to RO System
4 SBR System – 130K GPD capacity; targeting BOD/COD, Ammonia, and TSS removal
(1) 500,000 gal EQ; (1) 680,000 gal SBR reactor; (1) 90,000 gal post SBR EQ; (1) 90,000 gal WAS holding; MMF; RO effluent polishing Sequencing Batch Reactor (SBR) Original Master Plan: 2 additional SBR reactor and post EQ PREVIOUS BIOLOGICAL TREATMENT TRAIN • Increased hydraulic capacity • Projection for potential TN limit 5 SBR BLOCK FLOW DIAGRAM
Final Effluent
Treated REVERSE Leachate MULTI OSMOSIS EQ SBR POST SBR EQ MEDIA (500,000 gal) (680,000 gal) (90,000 gal) FILTER
Brine
Waste Solids WAS DISPOSAL HOLDING (90,000 gal)
DISPOSAL
6 Advantages
. Familiar technology . No RAS . 25+ years of success in leachate treatment
Limitations
. Limited SRT flexibility – less resilient to Sequencing Batch influent fluctuation Reactor (SBR) . Increased residuals management with expansion . Effluent quality issues due to poor (CONTINUED) settling . MMF required before RO . Large footprint 7 Membrane Bioreactor (MBR) Upgrades
1.2 MG EQ capacity; (2) 372,000 gal capacity 289K GPD design MBR reactors; (2) ultra Master Plan: capacity; targeting Solids dewatering filtration skids; (1) 90,000 Anoxic zones if BOD/COD, Ammonia, via centrifugation gal post MBR holding EQ; TN limit arises and TSS removal (1) 90,000 gal WAS holding; RO effluent polishing
8 MBR BLOCK FLOW DIAGRAM
Final Effluent
REVERSE OSMOSIS
EQ EQ MBR MBR (500,000 gal) (680,000 gal) 372,000 gal 372,000 gal Brine MBR PERMEATE HOLDING DISPOSAL RAS RAS (90,000 gal)
WAS HOLDING (90,000 gal) Waste Solids ULTRA Permeate FILTER
Centrate to MBR Reactors Cake to Disposal CENTRIFUGE
9 Membrane Bioreactor (MBR) Upgrades (cont.) Advantages Limitations . SRT flexibility: increased MLSS, produces less WAS . Cleaning (mineral and biological fouling) . Resilient to loading (strength and flow) compared . Adjustment to new technology to SBR . Heat load: . Footprint: typically 1/3 to 1/4 the size of • UF RAS conventional activated sludge-type treatment plants • Foaming (insulating effect) . UF: combines function of clarifier and filter before • Biological heat of reaction RO; removed hydraulic loading from MMF
10 TECHNOLOGY TRANSITION – EQUIPMENT Repurposed existing infrastructure Expanded EQ with former SBR tank
Feed pumps, blowers – reused and expanded
RO
WAS and permeate storage
New infrastructure – designed with flexibility (2) MBR reactors – 50% capacity
(2) UF skids – 1 skid/MBR reactor, 2 banks/skid
Centrifuge
Building
Obsolete infrastructure
Multi media filtration 11 MBR START-UP
Key advantage for start-up transition:
1 Acclimated SBR biomass
2 Direct transfer to MBR reactors
3 Summer start-up avoids freezing issues
Result:
Minimal lapse in treatment: < 2 days to transition and attain treatment Operational Observation (MBR)
Acceptable removal of COD and Ammonia – comparable to SBR
Increasing biomass inventory leads to initial decrease in flux
Sustained flux attained as MLSS stabilizes
CIP – mineral and biological fouling
13 Operational Comparison – Temperature
Contributions to heat load: RAS, foaming, biological heat of reaction
Thermal modeling performed during design
Biological treatment maintained throughout, irrespective of temperature
14 Operational Comparison – Reverse Osmosis
SBR/RO feed quality to RO – fluctuating TSS
MBR/RO feed quality – improved and consistent feed quality to the RO upon transition of technology
15 Operational Comparison – Reverse Osmosis (continued)
RO Skid #1 RO Skid #2 Assessed operation between cleanings, between SBR/RO and MBR/RO operation
Both skids: process increased volume between cleanings RO skid #1: additional 157,000 gal [+5 days] RO skid #2: additional 325,000 gal [+6 days]
Still assessing the long-term benefits to the RO
16 Both SBR and MBR consistently met all permit conditions
MBR produces higher quality feed to RO
Short term savings: RO CIP chemical consumption Long term savings: RO membrane replacement cost Conclusions Removes need for multi media filtration and associated backwash hydraulic loading
Increased process/treatment efficiency
MBR technology has an overall footprint advantage
17 OBG |PRESENTS: THERE’S A WAY Thank you! [email protected]