In this paper, the purification effects of different rice fish farming systems on aquaculture wastewater were studied through enclosure experiments. Results showed that paddy field, rice crayfish and rice crab farming systems all had significant purification effects on aquaculture wastewater, and there was no significant difference among different systems (P>0.05). The maximum removal rates of ammonia nitrogen, nitrite nitrogen, TN and TP were 67.48%, 78.13%, 37.97% and 53.05%, respectively. IMn and suspended solids in aquaculture wastewater were reduced to a minimum in 1~2 days, ammonia nitrogen was in 2~4 days, TN was in 4~8 days and TP was in 8~16 days. In addition, the co culture of crayfish and crab in paddy fields had no significant disturbance on the purification of aquaculture wastewater. |