Bio-filter purification system for pond aquaculture effluent

Two bio-filter beds packed with elasticity plastic filter or ceramsites were developed for the problems of low efficiency and large occupied area by traditional facilities of water purification in pond aquaculture. Additionally a bio-filter purification system for effluent in pond aquaculture was constructed. This system consisted of aquaculture ponds and these two kinds of bio-filter beds. The suitable hydraulic retention time(HRT)for purification of pond aquaculture effluent was determined by analyzing the purification effect. The optimal pond water circulation rate and area ratio between bio-filter beds and aquaculture ponds were determined by analyzing the pond water quality and changes of algae. When running the system at these optimized parameters, the nutrient of pond water can be maintained at low level, meanwhile, the structure of algae community has been optimized, and the water consumption and pollution emission are reduced. This system was used successfully in several pond aquaculture farms. It would be a new method for reuse of pond aquaculture effluent.