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Building a Continuous Flow Wastewater Treatment Plant. Aliza. Dan. Dave. 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.
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Building a Continuous Flow Wastewater Treatment Plant Aliza Dan Dave
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
FRIDGE B Air flow regulator Settling basin Centrifugal pump reactor Peristaltic pump waste Clean water (to dilute BOD) Treated effluent BOD 5 6 4 air source 1 clean water to drain A BOD sludge recycle 3 waste 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) aeration . . .. 2 sludge recycle aeration and stirring Continuous Flow Wastewater Treatment
Controls 5 Only Conditions • BOD flow in • Water flow in • Sludge recycle • Effluent Removal • Default pump in short bursts to better regulate flow (low flow rates are less accurate) Solids retention Increase residence time
Control States Port: 1 2 3 4 5 6 Computer Controlled Computer Controlled
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 elapsed time
Our Major Problem • Solids did not settle • Resulted in contaminated effluent
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
VSS Analysis • Volatile Suspended Solids • Measure of effluent quality • Filtration Evaporation Combustion
Conclusions • Semi-continuous flow achieved • Mixing promotes clarification • Solids retention and movement possible • Continuous flow not possible with equipment provided
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
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…