Abstract:The Release of phosphorus from sediments from the Hangzhou section of the Grand Canal and the effects of liming, ferric chloride addition, aeration and overlying water refreshment were studied in this paper.Two kinds of polluted sediments from the canal, one was sampled from sewage polluted section and the other sampled from the industrial wastewater polluted section of the canal, were used in the release experiment in the overlying water-sediment ratio of 1;5 (v/v).The results showed that, concentration of total phosphorus (TP) in overlying water was highest at the beginning of the release experiment with infrequently disturbed the overlying water, and decreased with the time of running.Release potential of the sediment sampled from the vSewage-polluled section was significantly higher than that of the sediment sampled from the industrial wastewater polluted section.Liming of overlying water resulted in the increase of TP concentration in overlying water, while ferric chloride addition and aeration lead to the decrease of TP concentration in overlying water.Overlying water refreshment also decreased the TP concentration in overlying water.However, all the above methods have not decreased the TP concentration in overlying water to 0.2 mg/L, which ivS the limitation value of the V catalog surface water., suggesting the release of phosphorus from the sediment of the canal could drastically affect the water quality.