Environmental Sciences Bulletin of The Korean Environmental Sciences Society
- Volume 3 Issue 2
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- Pages.113-119
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- 1999
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- 1226-6957(pISSN)
Automatic Control Of Dissolved Oxygen In Activated Sludge Aeration Tank
- Park, Kwang-Soo (Dept. of Environmental Engineering, Pusan National University) ;
- Heo, Nam-Hyo (Biomass Research Team, Korea Institute of Energy Research) ;
- Lee, Hae-Goon (Dept. of Environmental Engineering, Pusan National University) ;
- Han, Gee-Baek (Dept. of Environmental Industry, Sorabol College) ;
- Kim, Chang-Won (Dept. of Environmental Engineering, Pusan National University)
- Published : 1999.08.01
Abstract
The quality of the effluent from an activated sludge aeration tank can deteriorate when the substrate removal rate decreases due to an abrupt reduction in the DO concentration, which is affected by such operating conditions as the loading rate, temperature, wastewater composition, and so on. In this research, a DO control system that includes a PI (proportional-integral) controller/Hiraoka controller was developed and applied to a pilot-scale activated sludge process, then its acceptability was estimated. The applicability of the respiration rate to DO control was also estimated. The respiration rate indicated a variety of input organic loading rates, which is the main disturbance to the DO concentration in an aeration tank. When the influent concentration incrementally decreased and increased between CODcr 1,000 mg/l and 100 mg/l, the control system with a PI controller exhibited a good llperformance-the average DO concentrations were 2.00