Study on the P Release from Sediments of the Hangzhou Section of the Grand Canal, China

Abstract

采用室内模拟的方法研究了扰动情况下运河(杭州段)表层沉积物磷的释放对上覆水的影响以及投加石灰、投加三氯化铁、连续曝气、换水清洗等措施对沉积物磷释放的控制效果.研究表明,在扰动、开放体系条件下,运河(杭州段)沉积物磷释放导致的上覆水总磷浓度在释放初期最高,随时间逐渐下降,表现出净吸附.采集于有机污染较重河段的沉积物磷释放能力显著高于总磷含量较高但以重金属污染为主的河段的沉积物.上覆水投加石灰最终导致沉积物磷释放量的增加.投加三氯化铁显著降低了上覆水总磷浓度.上覆水连续曝气降低了上覆水的平衡磷浓度.换水清洗对上覆水磷浓度的降低效果是有限的.然而上述措施均未能将上覆水总磷浓度控制在V类水的浓度限定值以下.因此,就上覆水TP的浓度指标而言,运河(杭州段)沉积物的内源释放对其影响很大.;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.