Design And Research On A Pilot Treatment System Of Wastewater From Aquaculture Industry

The demand in aquatic product has been greatly increased as the people’s living standard is raised. Overfishing has resulted in the exhaust of fish product in nature. Under this situation, the aquaculture has taken the chance to develop fast, and has greatly met people’s demand in aquatic product. However, aquaculturing in high density resulted in a serious water pollution caused by its discharge wastewater without proper treatment. High concentration of nutrients in the aquaculture effluent is a great risk to water eutrophication problems. The control of aquaculture wastewater discharge is of great meaning to the environment protection.This research was conducted in order to find a way for the control of pollutants in the aquaculture effluent. Constructed wetlands(CWs) and Multy-soil-Layer system (MSL) have been separately used in the wastewater treatment of aquaculture, based on the previous investigation and a serious of A bench-scale experiments. Which was carried out before the design of the pilot project.During operation period of the MSL system, the average concentration of pollutants in effluent is as follows:COD49mg/L, TN4.28mg/L, NH3-N3.99mg/L, TP0.24mg/L, and the removal rates are:COD75.4%, TN50.3%, NH3-N52.2%, TP67.4%. The average concentration of pollutants in effluent from the CW system is: COD18.49mg/L, TN8.47mg/L, NH3-N7.10mg/L, TP0.32mg/L with the removal rate of COD71.2%, TN49.6%, NH3-N45.3%, TP74.0%. The effluent from of the two systems could meet the requirement of reuse by aquaculture.The pilot experiment showed that constructed wetland and MSL performed a good results in the treatment of wastewater from aquaculture and the stability in performance, lower cost in investment and operation, and convenience in maintenance made them to be worth of use in treating aquaculture wastewater.