The water environmental capacity of Xinghai Lake was assessed by full mixed model based on the monitoring data of permanganate Index(IMn), chemical oxygen demand (COD), five day biochemical oxygen demand (BOD5), ammonia nitrogen (NH3〖FK(W。*9〗〖CD*2〗〖FK)〗N), total nitrogen (TN), total phosphorus (TP) from 2015 to 2017, for preventing water quality from deteriorating, and reaching water quality standard Ⅳ, Ⅲ or Ⅱgrade. The results showed that the water environmental capacity for IMn was stable, the mean environment capacities under 4 control targets in the three years were 882.90 t/a, 2 366.76 t/a, -195.29 t/a and -1 476.31 t/a, respectively. The environmental capacity for COD decreased year by year. The environment capacity for BOD5 fluctuated, and increased significantly in 2016. The load of NH3〖FK(W。*9〗〖CD*2〗〖FK)〗N in water was close to the environmental capacity under water quality standardⅡgrade target. The environmental capacity for TP and TN were insufficient, revealing the urgence of TP, TN reduction. |