Simulation of sedimentary phosphorus release under sediment disturbance
底泥扰动状态下内源磷释放过程模拟研究

The course of sediment disturbance time after time was simulated to study the effect of sediment disturbance on the release of sedimentary phosphorus.The results show that dissolved phosphorus(DIP,DTP)decreased markedly when sediment disturbance was over immediately(0 h).However.delayed release was observed after sediment disturbance was over(1 h,6 h,24 h).The amount of delayed release of DIP and DTP was the largest at 1~(st)day,up to 20.01 mg/kg,22.12 mg/kg,16.85 mg/kg and 17.21 mg/kg,22.12 mg/kg,9.69 mg/kg respectively,at the sampling time of 1 h,6 h and 24 h.The value was reduced by 44.80%～57.87%and 42.52%～61.24%,respectively at 2~(nd)day.The delayed release was transformed into negative release gradually with the frequency of sediment disturbance increase.Moreover,the value of DIP/TP and DTP/TP decreased gradually,too.It was indicated that sediment disturbance should promote the migration of dissolved phosphorus from overlying water to sediments and enhance the immobility of sedimentary phosphorus.All these resulted in the reduction of phosphorus availability.It was suggested that sediment disturbance could hinder the development of water eutrophication.