This study was designed to find a process of sludge reduction by biofiim method in wastewater treatment plants. We were able to develop a process which produces a sharp sludge reduction and better treated water. It was also possible to maintain a stable treatment efficiency to the variations of the temperature and the pollution load of wastewater. When the retention time is 2.5, 3.5, and 5 hours, 21㎎/day, 23㎎/day, and 27㎎/day of sludge was produced respectively. HRT 2.5 hours seemed to be the most efficient and economical. Under consideration of treatment efficiency and the amount of sludge production. MLSS 15,000∼20,OOO㎎/l was most effective. In low waste load, medium waste load and high waste load, 11㎎/day, 14㎎/day, and 18mg/day of sludge was produced respectively. This means that the treatment efficiency was stable in different load conditions of inflow water. |
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