抄録
Two laboratory-scale biological filter treatment systems packed with ceramics media and plastic media and control system withuot biological filter process were operated to treat polluted pond water. Three algal culture tanks with sufficient nutrient and light for growth were used as polluted ponds. A portion of water from the algal culture tank was withdrawn and treated through the biological filter process. The effluent was recirculated into the algal culture tank. Treatment performance of biological filter system was compared based on water quality of three algal culture tanks. The range of circulation ratio (feeding rate to biological filter process divided by the volume of the algal culture tank) was varied from 1.5 d-1 to 0.1 d-1. Growth of algae was depressed and sedimentation rates of suspended solids increased in the tank with biological filter process even if the circulation ratio was low (i.e., 0.1 d-1). There was no difference between water quality and algal composition in the two tanks with two different packing media. The biological filter process could increase the transparency of polluted pond water and the diversity of algal species compared to the control tank.
