Abstract
An artificial algal bed of carbon fibers floating on the water surface is a natural purification system using the biological purification capability of a lake. The amount of sludge adhered to carbon fibers was 34.3 times the carbon fibers' absorbed amount. The water purification performance of sludge adhered to the carbon fibers was investigated using a laboratory-scale batch aeration tank. Lake water was passed through the circulation tank situated in the shore of Lake Onuma. Results show that the attached biofilm of carbon fibers' sludge are effective in removing pollutants from water. Under optimum conditions, the treated water amount during the experimental period was calculated as 480L•kg-S-1-day-1 , with retention time of 4.3h. The rate of particulate matter removal was 196 mg•kg-S-1-day-1, the COD rate was 98.4 mg•kg-S-1-day-1. An algal attraction effect by the nutrients of algae was recognized: nutrients adhered on carbon fiber were absorbed by the sludge, thereby clarifying the water.
