【摘要】 2009～2011年分阶段对宁波市城区不同类型内河进行了水质和底质(沉积物)污染特征研究,结果表明:目前宁波市内河水质总体属劣Ⅴ类,主要污染因子为TN、NH3-N、TP、CODMn;主要景观河道的水质好于一般河道,城中村河道水质最差,但差异并不大;内河水质的电导率、CODMn、TN、NH3-N、TP和Chla之间的相关性显著(R2=0.64～0.97),水体pH值受控于蓝绿藻,呈夏季高冬季低;连续降雨对水体水质有不同程度的稀释作用,短暂的水量补充对提高内河水质分类等级作用不大;清淤整治后水质有明显好转,其中CODMn、TP指标下降明显,TN指标虽然下降了21%仍超标严重;内河沉积物的主要污染因子为有机质、氮、磷,沉积物的耗氧量非常大,这是导致水质二次污染的重要原因.更多还原

【Abstract】 According to the study on the pollution characteristics of water qualities and sediment in different inner rivers of Ningbo from 2009 to 2011,the water qualities of Ningbo inner rivers are ranked at Grade V currently,and the main pollution agents are identified as being TN,NH3-N,TP and CODMn.The water qualities of landscape rivers,on the other hand,are found to be better than common rivers,and the water qualities of the rivers in village amidst the city are considered the worst with almost the same pollution level.The relative coefficient among electric conductivity,CODMn,TN,NH3-N,TP and Chla are higher(R2=0.64-0.97),and the pH of water body is controlled by cyanobacteria,which turns higher in summer than that in winter.Although the continuous rainfalls may improve water quality by diluting,it has little impact on improving water quality of inner rivers just because of addition of water.The water quality is obviously improved after dredging,and this improvement can be manifested by the indices mitigation of CODMn,TP.The main pollution agents of the sediments include organic,nitrogen and phosphorus,and these elements consume enormous amount of oxygen,resulting in secondary pollution that is responsible for deterioration of water quality.更多还原