Deborah Helstrom, P.E. Utilities Technical Review Water Supply Division 512-239-6705 dhelstro@tceq.state.tx

1. 217.157 Membrane Bioreactors Treatment Systems (MBR) Deborah Helstrom, P.E. Utilities Technical Review Water Supply Division 512-239-6705 dhelstro@tceq.state.tx.us

2. 217.157 Membrane Bioreactors Treatment Systems (MBR) • Information used to draft • What it contains • How to use the rule

3. Membrane Bioreactors (MBR) Compiled Surveys from Vendors of Membranes • Huber, Koch, Kruger, Kubota, Siemens, Zenon Results of Survey, Literature and Other State Regulations Concerns • Prevention of Fouling • Adequate aeration at high MLSS concentrations • Achievable rate of flow through membranes • Adequate pretreatment i.e. fine screening • Hydraulics • Ensure Integrity • Foam Control • Warranty • Nutrient Removal

4. Membrane Bioreactors (MBR) Applicability • Submerged • Low-pressure, vacuum or gravity • Ultrafiltration or microfiltration • 217.8(b)(2) Approval of Nonconforming and Innovative Technologies • May require pilot study and/or 2 year performance bond

5. Membrane Bioreactors (MBR) Expected Performance • CBOD5 5 mg/l • TSS 1 mg/l • Ammonia 1 mg/l • Total Nitrogen (w/pre-anoxic zone) 10 mg/l • Total Nitrogen (w/pre-anoxic and • post-anoxic zone) 3 mg/l • Total Phosphorus (with chemical addition) • 0.2 mg/l • Total Phosphorus (with Bio-P removal) • 0.5 mg/l • Turbidity 0.2 NTU • Bacteria up to 6 log removal (99.9999%) • Viruses up to 3 log removal (99.9999%) If proposed design is for higher quality effluent, Pilot Study or Data from Similar Facility

6. Membrane Bioreactors (MBR) Membranes Hollow fiber or Flat plate Nominal Pore Size Microfiltration 0.10 – 0.40 microns Ultrafiltration 0.02 to 0.10 microns Common Membrane materials Pretreatment Fine Screen - perforated plate or drum Hollow fiber 1.0 - 2.0 mm Flat plate 2.0 - 3.0 mm No Bypass Primary clarifier Evaluated for > 1 MGD Grit Removal excessive I/I Oil and Grease Removal 50 mg/l

7. Membrane Bioreactors (MBR) Operation Average Daily Net flux rate @ 20 C 12 to 20 gfd Peak Daily Net flux rate @ 20 C 20 gfd Two Hour Peak Daily Net flux rate @ 20 C 24 gfd Operational Range for TMP Maximum Operational TMP Hollow Fiber 2.0 – 10.0 psi Max 12.0 psi Flat Plate 0.3 - 1.5 psi Max 3.0 psi Operational Range of MLSS Concentration Bio Reactor 4,000 - 10,000 mg/l Membrane Tank 4,000 – 12,000 mg/l Operational control parameters SRT 10 – 25 days

8. Membrane Bioreactors (MBR) Operation Amount of air used per square foot of membrane 0.01 – 0.04 SCFM / SF Method of Integrity Testing : In-line Turbidity <=1.0 NTU Hollow Fiber Pressure Decay Testing Surface Wasting to Foam Control Run in full manual mode or backup PLC Aeration alpha value of 0.5 or lower anoxic 0.5 mg/l DO aerobic 1.5 – 3.0 mg/l DO membrane 2.0 - 8.0 mg/l DO Nutrient Removal deoxygenate recycle recycle 300 – 600 percent

9. Membrane Bioreactors (MBR) Redundancy N+1, trains, units or storage. Show calculations Peak Flow Peak Ratio of 2.5 requires Equalization, off-line storage or reserve membrane capacity RAS rate 200 – 400 percent of influent Warranty 5 year on Membranes May require a 2 year performance bond

10. 217.157 Membrane Bioreactors Treatment Systems (MBR) • Engineering Report Required • Common range of values • Justification for using parameters outside the common range • May be required to provide 2 year performance bond

11. Membrane Bioreactors References • “So, You Decided to Build an MBR?: Tips to help optimize process performance”, Merlo, Rion et al, WE&T, www.wef.org/magazine November 2006. • State of Washington, Department of Ecology, “Orange Book”, Sewage Treatment Design Criteria • Water Environment Federation, Membrane Systems for Wastewater Treatment, 2006 • Manufacturers: • Huber, Koch, Kruger, Kubota, Siemens, Zenon