杭州市城区河道底泥污染特征分析

The Analysis on Sediments Pollution Characteristics of Urban Rivers in Hangzhou

以杭州市城区6条代表性河道为研究对象,通过对河道底泥中的pH、营养盐、有机物和金属污染物含量的监测和分析,总结其变化特征,为城区河道污染治理及底泥疏浚后的处置提供科学的参考依据。研究结果表明,城区河道底泥的pH均在7～8,呈中性偏碱性;部分河道底泥全氮、全磷以及有机质污染较为严重;重金属含量分布不均,Cd、Zn含量普遍较高。上述污染特征说明城区河道尽管进行了大规模的整治,但由于截污纳管不完全及水体流动性较差等原因,底泥沉积和污染速度较快,应加强底泥监测,定期清淤,建立健全长效管理机制,同时进一步深化截污纳管工程,加强环境引配水,推动水环境质量的整体提升。

Six representative rivers of Hangzhou urban area were selected as object of study, pH, nutrients, organic matter andmetal pollutants in the river sediment were monitored and analyzed. The variation characteristics of these indexes were, summarized providing a scientific basis for the disposal of urban river pollution control and sediment dredging. The result shows that pH valuesof urban river sediment are between 7 and 8, which means neutral to slightly alkaline; TN, TP and organic matter are seriously polluted in some rivers; the distribution of heavy metal content is uneven and the contents of Cd, Zn are generally higher. Theabove pollution features indicate that despite large - scale renovation, the speed of sediment deposition and pollution is faster due to incomplete of interception in a sewer, poor mobility of water body and other masons. Thus we should strengthen the monitoringof sediment, dredge on a regular basis, establish a sound long- term management mechanism, further deepen the interception in the sewer projects, strengthen environmental cited water distribution so as to enhance the overall promotion of water quality of theenvironment.