以3个典型小城镇河流为例,研究上海市小城镇河流沉积物重金属污染特征.结果显示,沉积物Zn的浓度在3.11~3.74g/kg之间,是农用污泥Zn使用允许最高值0.5g/kg的6~8倍,沉积物Zn的极度污染已经成为上海市小城镇河流沉积物区域性环境问题;沉积物Pb和Cu的浓度分别在0.03~1.00g/kg和0.07~0.20g/kg之间,小城镇河流沉积物也明显受到Pb和Cu污染且污染区域差异性大,沉积物中铁、锰、铬等重金属污染相对较轻;毒性弱的Fe,Mn,Zn沉积物区域污染差异性相对小,而毒性强的Pb,Cu,Cr区域差异性相对较大;沉积物重金属污染一般中型河流污染相对稍突出,小城镇河流沉积物由于Zn的严重污染不能用作施用污泥;利用重金属与TP,重金属与Fe之间的相关性探源结果显示:小城镇生活污水的地表排放使得街道灰尘成为河流沉积物Pb的一个重要来源.
By selected three small towns, we studied the pollution character of heavy metals in sediments. Results show that the content of sediments-Zn is between 3.11 g/kg and 3.74g/kg, which is heavily excess the criterion of farming fertilized by sullage. The Zn-pollution of sediments has been a territorial and heavily pollution question of small towns, the content of sediments-Pb is between 0.03 g/kg and 1.00g/kg, And that of sediments-Cu is between 0.07g/kg and 0.20g/kg. The river sediments has also been polluted by Pb and Cu. To the diversity-region, light-toxicity metals(Fe, Mn, Zn) is less than heavy-toxicity metals(Pb, Cu, Cr). The river sediments from small towns can not be fertilized to the farmlands. By analyzed the relativity of TP-metals(Fe, Cr, Cu, Mn, Pb, Zn) and that of Fe-metals(Fe, Cr, Cu, Mn, Pb, Zn), we can conclude living sewage form small towns is a source of metals in sediments. Street-dust is an important source of sediments-Pb through surface-eroded by living-sewage.