Abstract
In this report, the performance of up-flow charcoal bed contact treatment plant was experimentally investigated to determine the design-operating parameters and its proper maintenance method to ensure effective purification. Some improvements (e.g., in flow direction, and lower part of tank) have been made on this plant. In this experimental plant, polluted water runs through charcoal bed in the upward direction, which is different from conventional gravel bed contact treatment plant, where contaminated water runs in the horizontal direction. Water-purification test, biological test, and a test on maintenance methods were conducted, with using river water and secondarily treated domestic waste water.
Removal efficiencies of BOD, SS, T-N and T-P were approximately 80%, 90%, 30% and 40%, respectively, at about 30-40 minutes of contact time. Also, it became apparent that the SS removal in influent part of the plant was expected to allow long-term purification without the rapid development of clogging in charcoal bed. The aeration-washing of the charcoal bed with diffuser avoided the deterioration of treatment performance due to the clogging. Therefore, up -flow charcoal bed contactpurification seemed to have a advantage to treat river water polluted.
