Abstract: According to the different functions of various living organisms and their synergistic effects, the multiple bio-treatment system was established. The system consisted of the floating bed of the aquatic economic plants, Phragmites australis wetland, artificial immobilized microbial membranes, benthic molluscs and filter-feeding fish. Except the Phragmites australis wetland and filter-feeding fish, all above were set to the multiple bio-treatment drain conduit. And this not only made full use of the water, saved the materials and energy, improved the purifying efficiency, but also regulated and purified the water quality in the culture ponds effectively, and thus realized the water recycling discharged by the culture ponds, and improved the breeding benefits. The results show that through the purification of the multiple bio-treatment system, the phytoplankton biomass in the discharged water from the breeding ponds was 69.114-43.832 mg/L, which was reduced by 13.44%-0.47% on inin average. Especially, cyanobacteria was reduced by 58.41%-51.63% on average.

Key words: multiple bio-treatment system, culture pond, phytoplankton, bioremediation