浑河上游(清原段)水环境中重金属时空分布及污染评价

Temporal-spatial Distribution and Pollution Assessment of Heavy Metals in the Upper Reaches of Hunhe River( Qingyuan Section),Northeast China

为了解浑河上游(清原段)水环境中重金属污染水平及其污染程度,对浑河上游(清原段)表层水体和表层沉积物中6种重金属(Fe、Mn、Cu、Zn、Cd、As)的含量及时空分布分别进行了研究,并分别采用综合污染指数评价法和地累积指数评价法对表层水体和表层沉积物中4种重金属(Cu、Zn、Cd、As)的污染程度进行了评价.结果表明,浑河上游表层水体Mn、Cu、Zn、Cd、As的季节变化均表现为丰水期含量高于平水期和枯水期.表层水体Fe、Mn、Cu、Zn、Cd的沿程变化趋势基本相似,均在H7站出现最高值.不同水文时期的水体pH值、硬度和DO值对水体重金属含量分布产生的影响各不相同,水体重金属相互之间存在一定的显著性相关关系,说明它们之间可能具有一定的同源性.浑河上游表层沉积物中Cu、Zn、Cd、Fe这4种重金属的季节变化规律均为:枯水期>丰水期>平水期.表层沉积物中Mn、Cu、Zn、As、Cd这5种重金属的沿程变化相似,均在中间出现一个最高值.采用综合污染指数评价法表明,浑河上游水体大部分水质良好,个别站位重金属污染比较突出.采用地累积指数法评价表明,浑河上游表层沉积物主要以Cu、Cd、As污染为主.

The aim of this article is to explore the pollution level and contamination degree of heavy metals in the upper reaches of Hunhe River （Qingyuan Section）. The contents and temporal-spatial distribution of Fe, Mn, Cu, Zn, Cd and As in surface water and surface sediments from the upper reaches of Hunhe River were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of Cu, Zn, Cd and As. The results indicated that the contents of Mn, Cu, Zn, Cd and As in surface water from the upper reaches of Hunhe River during the wet season were higher than those during normal and dry season. Similar patterns of spatial distribution of Fe, Mn, Cu, Zn and Cd in surface water were observed, which showed that the highest content appeared at H7 station. The influence of pH, DO and hardness in the upper reaches of Hunhe River during the wet, normal and dry season on the distribution of heavy metal contents in surface water varied. Significant positive correlations were found among these elements in surface water, which implied that these elements probably had common pollution sources. The contents of Cu, Zn, Cd and Fe in surface sediments from the upper reaches of Hunhe River during the dry season were higher than those during the wet and normal season. Similar patterns of spatial distribution of Mn, Cu, Zn, As and Cd in surface sediments were also observed, which showed that the highest metal contents appeared in the midway of Hunhe River. The integrated pollution index assessment showed that the water quality in the upper reaches of Hunhe River was good except for individual stations, and that Cu, Cd and As were the main pollution elements in surface sediments in the upper reaches of Hunhe River.