Deborah Helstrom, P.E. Industrial Permits Team Wastewater Permitting Section 512-239-6705

1. 217.158 Membrane Bioreactors Treatment Systems (MBR) Deborah Helstrom, P.E. Industrial Permits Team Wastewater Permitting Section 512-239-6705 dhelstro@tceq.state.tx.us

2. Membrane Bioreactors (MBR) Combination: Activated Sludge Membrane filtration (replaces secondary clarifier)

3. Ultrafiltration Membranes

4. Ultrafiltration Membranes

5. Hollow Fiber Membranes

6. Flat Plate Membranes

7. Other Configurations

8. Membrane Bioreactors (MBR) • Advantages • Smaller Footprint • High Quality Effluent • Automatic Control • Less Sludge • Disadvantages • Capitol Costs • Energy Costs for Aeration and Scouring • Highly Variable Flow require Equalization

9. 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 (typical) <0.05 mg/l (achievable) • Total Phosphorus (with Bio-P removal) • <0.5 mg/l • Turbidity <0.2 NTU • Bacteria up to 6 log removal (99.9999%)

10. Membrane Bioreactors (MBR) • Currently Compiling Surveys from Vendors of Membranes to Develop Design Criteria • 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

11. Membrane Bioreactors (MBR) Results of Survey, Literature and Other State Regulations Membranes Nominal Pore Size Absolute Pore Size Pretreatment Fine Screen (Type, Size) Primary clarifier, Grit Removal, Oil and Grease Removal (When required)

12. Membrane Bioreactors (MBR) Results of Survey, Literature and Other State Regulations Operation Gross Flux Rate @ 20 C Net flux rate @ 20 C Operational Range for TMP Maximum Operational TMP Operational Range of MLSS Concentration in Bio Reactor Operational Range of MLSS Concentration in Membrane Tank Operational control parameters used and range of values (Turbidity, SRT, DO, TMP, ORP) Amount of air used per square foot of membrane Method of Integrity Testing (i.e. Turbidity) Method of Foam Control

13. Membrane Bioreactors (MBR) Results of Survey, Literature and Other State Regulations Maintenance clean Method Frequency Chemical clean Frequency Chemicals used Concentrations

14. Membrane Bioreactors (MBR) Results of Survey, Literature and Other State Regulations Redundancy N+1 or other method Peak Flow Peak Ratio which requires Equalization RAS rate (#Q) Hydraulics Head required for Gravity Controls Method of backup for controls Warranty Membranes, other equipment and process

15. 217.158 Membrane Bioreactors Treatment Systems (MBR) • Engineering Report Required • Common range of values • Justification for using parameters outside the common range • 2 year performance bond

16. 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, U.S. Filter, Zenon