赣江上游龙迳河水体氨氮与重金属污染分布特征及风险评价

论文以我国典型的稀土矿区流域——赣江上游龙迳河为研究对象，自上游至下游采集了15个水样并现场测定了水体pH值，测试和分析了氨氮、硝氮、亚硝氮和Cr、Cd、Zn、Cu、As、Hg、Pb、Mn 8种重金属含量和相关性，并采用内梅罗综合污染指数评价法对重金属污染程度进行评价.结果表明:①龙迳河流域主要的重金属污染物为Mn、Hg、Pb，其超出地表Ⅱ类水质标准分别为93%、20%、6.7%；②表层水体中亚硝氮、硝氮、氨氮和重金属Zn、Mn、As、Cd、Pb沿程变化具有相似性，且重金属Zn、Mn、As、Cd、Pb与氨氮具有显著的正相关性，表明重金属Zn、Mn、As、Cd、Pb之间可能具有一定的同源性且氨氮含量与该重金属在水中的分布有密切联系；③龙迳河水质优良、良好、较好、较差和极差占整体采样点的概率分别为6.67%、26.67%、33.33%、6.67%和26.67%，河流水质整体较差，部分采样点水质较好，重金属污染上游大于下游. 

Distribution characteristics and risk assessment of ammonia nitrogen and heavy metal pollution in Longjing river,the upstream of Ganjiang river

Longjing River, one of China's typical rare earth mining areas, in the upper reaches of the Ganjiang River is studied. 15 observation sections was set up to test and analyze the content and correlation of ammonia nitrogen, nitrate nitrogen, nitrous oxide and 8 heavy metals such as Cr, Cd, Zn, Cu, As, Hg, Pb, Mn. N.L.Nemerow comprehensive pollution index evaluation method was adopted to evaluate heavy metal pollution. The results show that: ①The main heavy metal pollutants in the Longjing River Basin are Mn, Hg and Pb, which are 93%, 20% and 6.7% higher than the surface Ⅱ water quality standards respectively; ②Nitrous oxide, Nitrogen, Ammonia and heavy metals such as Zn, Mn, As, Cd and Pb in the surface water have similarities along the process, and heavy metals such as Zn, Mn, As, Cd, Pb and Ammonia have a significant positive correlation. It indicates that there is homology between Zn, Mn, As, Cd and Pb, and the Ammonia nitrogen content is closely related to the distribution of heavy metal in water; ③Water quality of Longjng River is classified into 5 degress from the best, better, good, bad and worse. The probability of each is 6.67%, 26.67%, 33.33%, 6.67% and 26.67%. The water quality is poor in general. Some sampling points show good water quality, and heavy metal pollution in upstream is heavier than that in downstream.