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HomeMy WebLinkAbout03.b. Update on the Membrane Aeration Biofilm Reactor Process Intensification TestingPage 1 of 6 Item 3.b. F__1_448�411C_S0 July 19, 2023 TO: REAL ESTATE, ENVIRONMENTAL AND PLANNING COMMITTEE FROM: MICHAEL CUNNINGHAM, ASSOCIATE ENGINEER NITIN GOEL, OPERATIONS OPTIMIZATION DIVISION MANAGER REVIEWED BY: GREG NORBY, DEPUTY GENERAL MANAGER ROGER S. BAILEY, GENERAL MANAGER SUBJECT: RECEIVE UPDATE ON THE MEMBRANE AERATION BIOFILM REACTOR PROCESS INTENSIFICATION TESTING The attached presentation provides updates on the Membrane Aeration Biofilm Reactor Process Intensification Testing. Strategic Plan re -In GOAL TWO: Environmental Stewardship Strategy 1 - Achieve compliance in all regulations, Strategy 4 - Identify and advance sustainability initiatives, including reducing energy usage and emissions GOAL SIX: Infrastructure Reliability Strategy 1 - Manage assets optimally, Strategy 2 - Execute long-term capital renewal and replacement program GOAL SEVEN: Innovation and Agility Strategy 2 - Implement organization -wide optimization, Strategy 3 - Be adaptable, resilient, and responsive ATTACHMENTS: 1. Presentation July 19, 2023 REEP Committee Meeting Agenda Packet - Page 26 of 33 Page 2 of 6 ATTACHMENT 1 July 19, 2023 If Membrane Aeration Biofilm Reactor Process Intensification Testing =Ram&-- %AonL Nitin Goel Optimization Division Manager Steam and Aerations Blower Systems Renovations District Project (DP) 7349 Secondary Process Spin -Off Projects Planning Design Construction Identified Asset Replacement based on Developed plan to maximize the capacity Electric Blower Improvements DP drivers: of existing tanks, if nutrient removal 100015 - Near completion, two of three Aging Infrastructure were needed, and avoid stranded assets. new electric blowers commissioned. • Capacity Membrane Aeration Biofilm Reactors Aeration Basin Diffuser Replacement & • Regulatory identified as technology that could Seismic Upgrades DP 100019 - Bid • Sustainability/Optimization intensify treatment in existing tankage phase complete, construction begins in (i.e., do more in the same space). May 2024. Phase 1 will take two summers. Vision to Maximize Value of Existing Secondary Process J July 19, 2023 REEP Committee Meeting Agenda Packet - Page 27 of 33 1 Page 3 of 6 Process Configuration After Current Projects are Complete Electric Blower Improvements Project DP 100015 Full redundancy for air supply to tanks with new electric blowers Aeration Basin Diffuser Replacement and Seismic Upgrades DP 100019 Replace aged diffusers with state-of-the-art membrane diffusers for improved efficiency and performance Rehabilitate south selector to allow for north selector to be taken offline for rehabilitation and allow for new treatment configuration Comprehensive Wastewater Master Plan Placeholder Plan for Nutrient Removal If nutrient removal were required for a recycled oama's'°" water project (i.e., Water Exchange) or regulatory requirement, Modified Ludzack Ettinger (MLE)* is the pLacehoLder process. Benefits Established and proven treatment process. Challenges Significant construction effort for contaminated soil relocation/removal and new secondary clarifiers F and aeration tanks. µ:AY° Completing maintenance in dry weather season (May -October) could require adding new staff or seasonal contractors. I Stl¢LM10 E0111 APGOtI5dgd1[SYldldlg¢ Plk Sdtl b 9 ni1-01 Otl H"IR ` process increase the solids retention time to allow bacteria who use nitrogen as a food source to grow. This require more aeration tank volume and clarifiers to treat the same capacity. July 19, 2023 REEP Committee Meeting Agenda Packet - Page 28 of 33 2 Page 4 of 6 Alternatively, Membrane Aeration Biofilm Reactor (MABR) Technology Could Removal in Existing Tanks Cassettes consisting of many membranes are placed into an anaerobic zone (no added air) of a tank or channel. Air flows through the membrane allowing a biofilm of bacteria to grow on the surface. This biofilm bacteria population attached to the cassettes, unlike Central San's current bacteria population, use nitrogen as food. Therefore, they add nutrient removal capacity without adding clarifiers or aeration tanks. Maximize Nutrient ZeeLung Filament ZeeLung Cord ZeeLung Module ZeeLung Cassette ',� -fir I w ZOO Process Intensification Pathway Identified in Steam Project IN N I . �1 'T N Ni If nutrient removal is required for recycled water projects (i.e., Water Exchange) or to meet regulatory permit limits, MABR cassettes could be installed into selector channels or parts of aeration tanks. Ultraviolet Disinfection Replacement and Hydraulics Improvements Project DP 10012 will build a new ultraviolet facility in the contractor staging area. Then, it is possible MABR cassettes could also be installed within existing ultraviolet tanks to further increase nitrogen removal capacity. July 19, 2023 REEP Committee Meeting Agenda Packet - Page 29 of 33 3 Page 5 of 6 Pros and Cons MLE vs MABR if Nutrient Removal Were Required MLE: Comprehensive Wastewater Master Plan Placeholder Technology Pros Established and proven technology Cons Requires relocation of contaminated soil and new clarifiers and aeration tanks MABR: Intensification Technology Pros Maximizes treatment capacity of existing tankage More energy efficient than MLE Lower long-term maintenance requirement Cons Innovative & less established technology MABR Intensification Testing Near Term Benefits Obtain Critical Design Parameters: Determine the optimal design parameters to increase nitrogen removal in the existing tanks while understanding and learning what impact cyanide, in the existing Multiple Hearth Furnace air pollution control scrubber water, has on the MABR efficiency. Timing: Better estimating the equipment location, phasing and costs for a potential future MABR installation at Central San, which would help with Long-term capital improvement program budgeting. M July 19, 2023 REEP Committee Meeting Agenda Packet - Page 30 of 33 4 Page 6 of 6 Next Steps Testing duration expected to run from September 2023 to March 2024, followed by alternatives analysis to compare MABR with MILE process with updated design criteria. MABR Intensification Testing Budget: $300,000 funded from DP 100055 Process Optimization Project. If MABR pilot testing and updated evaluations are favorable, the next step would be installing a few cassettes in the selector channel during the final stages of the Diffuser Project for full-scale demonstration. Equipment Instaltation $50,000 Equipment Rental and Consultant Support $180,000 Technical Memo Design Criteria, Alternatives Analysis, and $40,000 Peer Review Central San Staff Time $20,000 Supplies/Laboratory Testing $10,000 Total $300,000 July 19, 2023 REEP Committee Meeting Agenda Packet - Page 31 of 33 5