污染河道的常量和微量元素特征及指示意义

CHARACTERISTICS OF MAJOR AND TRACE ELEMENTS IN CONTAMINATED RIVERS AND THEIR SIGNIFICANCE

河道常量元素和微量元素的分布既反映了不同的来源,又显示了污染水平。选择太湖周边具有不同污染源特征的漕桥河、梁溪河和大浦河,针对水体、悬浮物、沉积物3种不同介质,研究其化学元素含量及变化。微量元素特征及变化分析表明,3条河流整体上磷的含量较高,金属元素在城镇和工业区河段较高。元素主成分分析显示,接纳工业废水、生活污水和农田径流的河流,主成分组成差别明显。元素特征对比值结果表明,不同介质中元素对的变化并不一致,不同河道大体反映了工业废水、农田径流和生活污水的特点;分配系数KD值的大小顺序为Fe>Al>Zn>Cr>Ni>K,多数元素的KD值都是漕桥河最高,梁溪河最低,Zn的KD值则是大浦河最高,漕桥河最低,反映了不同污染源的特征差别。指示元素的研究对于污染河道的治理是有意义的。

The distribution of major and trace elements reflects not only the source of material,but also the level of pollution.Chemical elements were determined in water bodies,suspended particulate and sediments for Caoqiao River,Liangxi River and Dapu River discharged by different pollutants.Data showed that phosphorus is high in three rivers and metals were high in the reaches of town and industrial regions.Primary component analysis displays the significant diversity because of rivers receiving industrial wastewater,manucipal sewage and farmland runoff.The elemental pairs of correlative elements revealed the different values in water bodies,suspended matter and sediments,and those differences reflected the characteristics of farmland runoff,industrial and municipal effluences and could be considered indicators of different pollutants.The partition coefficients of particulate to dissolved metals（KD）decrease with Fe〉Al〉Zn〉Cr〉Ni〉K,Most of them are highest in Caoqiao River and lowest in Liangxi River.KD of Zn is highest in Dapu River and lowest in Caoqiao River,which revealed the different pollution in rivers.It is useful to distinguish the rivers receiving different pollutants in the intense anthropogenic regions.