Abstract: Turtle aquaculture is a major Chinese aquaculture industry in rural areas especially in the Yangtze River Delta. The discharge of greenhouse turtle breeding wastewater has brought negative influences on the living and production water quality and safety for the surrounding residents. In this study, we used a static hydroponic system to treat greenhouse turtle breeding wastewater and a dynamic hydroponic system to treat the tail water discharged from the biological aerated filter. The results indicated that both of the hydroponic systems could efficiently remove pollutants. The removal efficiency of COD and TN was better in the static hydroponic system than in the dynamic hydroponic system, while there was no difference in TP removal. In addition, the uptake of N by Ipomoea aquatica accounted for 14.1%-17.5% of TN removal during the entire experiment, while the uptake of P accounted for 12.2%-13.0% of TP removal in the two systems. The I. aquatica static hydroponic system had advantages of easy operation and low cost, being suitable for the greenhouse turtle breeding wastewater purification. In order to decrease the Cr and Pb concentrations in the I. aquatica, the pretreatment should be strengthened. The results provided an important technical support for the application of I. aquatica hydroponic system for treating greenhouse turtle breeding wastewater in China.

Key words: eutrophication, biological nitrification-denitrification, biogeochemical process, plant assimilation, eco-hydrological process