三峡水库上游(宜宾至泸州段)水体重金属分布特征及其来源

An Analysis of the Distribution Characteristics and Source of Heavy Metals in Water Body of the Three Gorges Reservoir (Between Yibin and Luzhou)

为调查长江上游城市工业园区重金属污染问题,选择长江干流(宜宾至泸州段)及其汇入支流,分析了Cu,Zn,Ga,Nb,Cr等18种重金属元素在江水和沉积物中的分布情况,并分析了其可能来源。结果表明,长江干流及其支流水体中,Ti,Fe,Mn,Ni质量分数水平较高,超过了相关标准限值;沉积物中Cd,Sn,Ti,Fe,Ta污染较为严重,尤其是Cd在支流永宁河、岷江入江断面和宜宾市区段的含量超标10倍以上;通过主成分分析,上述重金属污染主要与工业集聚等有关,泸州市和宜宾市大量的煤炭开采业,化肥制造业,以及造纸业可能是区域重金属污染的主要来源。上述研究结果表明,目前长江上游干流重金属污染水平不高,但部分支流存在较为严重的重金属污染问题。考虑到重金属的累积作用,有必要对区域的重金属污水排放进行管控,以消除污染对区域人群健康的威胁,实现长江生态大保护的战略目标。

The main stream as well as the branches of the Yangtze River between Yibin and Luzhou were select-ed to investigate the heavy metal pollution deriving from the city industrial park in the upper reaches of theYangtze River.18 heavy metals （such as Cu, Zn, Ga, Nb and Cr） in river water and sediments were measuredand the sources of these metals were analyzed. The results show that concentrations of some heavy metals includ-ing Ti, Fe, Mn, and Ni, have exceeded the criteria limit of national water standard of surface water or drinkingwater. For metals in sediments, the contents of Cd, Sn, Ti, Fe, and Ta were relatively high, especially for Cd,which is more than ten-fold higher than its threshold in the Yangtze River entrance of Yongning River, Minji-ang River, and Yibin section. Principal component analysis indicates that industry agglomeration in the upperreaches of the Yangtze River is mainly responsible for the metal pollution. Industries such as coal mining, chemi-cal fertilizer production and paper-making in Luzhou and Yibin, may be the main sources of heavy metals. Theresearch also reveals that the mainstream of the upper Yangtze is less contaminated by heavy metals. However,heavy metal pollution in some of the tributaries is severe. Considering that it may flow into the Yangtze Riverand accumulate, it is necessary to regulate the heavy metal effluent, thus get rid of the hazards for people＇shealth in these areas, and then realize our national strategy of ecological protection of the Yangtze River.