1. Building a Continuous Flow Wastewater Treatment Plant

2. Motivations for this Project Full-scale WWTP = continuous flow Previous groups unsuccessful Anticipated Hurdles Movement of solids Adequate residence time Coordinating necessary valves with available ports

3. Peristaltic pump FRIDGEreactor BOD.... Air flow regulator aeration waste Settling basin sludge recycle to drain Treated effluent aeration and stirring Clean water (to dilute BOD) 1 2 4 3 5 A Centrifugal pump B CONTROLS Port 1: airflow into accumulator Port 2: airflow out of accumulator Port 3: centrifugal pump on/off Port 4: treated effluent removal Port 5: organic feed Port 6: clean water (feed dilution) 6 clean water air source

4. Controls o BOD flow in o Water flow in o Sludge recycle o Effluent Removal o Default Only Conditions 5 pump in short bursts to better regulate flow (low flow rates are less accurate) Solids retention Increase residence time

5. Control States Airflow into accumulator Airflow out of accumulator Centrifugal pump Sludge removal Organic feed Clean water BOD flow in H 2 O flow in Sludge recycle Sludge removal Default Port: 1 2 3 4 5 6

6. State Change “Rules” Limited by software capabilities Can not run continuous while loops Sludge recycle and BOD feed not independent Simulate a continuous flow reactor Reactor always stirring and aerating Sludge recycle/disposal and BOD addition states change based on

7. Our Major Problem Solids did not settle Resulted in contaminated effluent

8. Attempted Solutions Addition of ferric chloride (coagulant) Big flocs….that floated Removed plastic ‘shield’ from clarifier Limited sticking to walls Mixing of solids in clarifier Outflow pipe facilitated re-suspension Better flocculation = better settling

10. VSS Analysis  Volatile Suspended Solids  Measure of effluent quality  Filtration  Evaporation  Combustion

11. Results

13. Conclusions Semi-continuous flow achieved Mixing promotes clarification Solids retention and movement possible Continuous flow not possible with equipment provided

14. Future Research and Improvements  Clarifier dimensions  Long and shallow  A second peristaltic pump for sludge recycle  Better control with more accurate flow rates  Approaching continuous flow  Larger activate sludge tank  Increase residence time

15. Any Questions?

16. This would not have even have been remotely POSSIBLE without the help of… Monroe Weber-Shirk, The handy guys in the basement shop, Jeff, Matt Fountain, Nick Wobbrock, Roslyn, Alex, Peter, John’s big ball of putty, All the other people in the lab, Jesus, NSF, Secretary of Defense Donald Rumsfield, My dog Kelsey, M. Todd Walter, Accel computing facility, Alexander the Great, Bill Gates, Labview, My parents, Edward Norton, Ned Nederlandy, The Big Guy Upstairs (Bisogni), The High-Noon Runner’s Club, Jill’s late-night massages, Dairy Bar, Farva, Harry Potter, Dave’s hair, The oven, Vietnam, Spicy Italian Bagels…