重金属在地表水和沉积物中的长期滞留和积累对水生生态系统的可持续发展和人类健康构成巨大威胁。在这项研究中,大型底栖动物,和地表水和沉积物重金属(锰,Cr,Cu,Ni,Pb,Zn,Cd,和As)样本于2019-2020年夏季从黑河上游和中游23处采集。通过Pearson相关分析和冗余分析(RDA)分析重金属与大型底栖动物的相互关系,用综合污染指数(WQI)评价地表水和沉积物中重金属的污染水平和潜在生态风险,单一潜在生态风险指数([公式:见正文]),和沉积物质量准则商(SQG-Q),分别。结果表明,黑河地表水重金属污染水平极低,但是Mn和Pb的含量超过了地表水环境质量标准(GB3838-2002)的第三类标准。表层沉积物中重金属的空间分布差异显著,8种重金属的平均浓度超过甘肃省的背景值。同时,表层沉积物中重金属的污染程度为高污染,生态风险等级为中度风险。结合[公式:见正文]和SQG-Q评估表明,Cd,Ni,Cr和Cr是主要的生态风险因子。此外,Cr和Cd的分布系数较低,表明Cr和Cd容易从表层沉积物中释放出来,造成二次污染。就重金属的来源而言,Cu,As,Zn,Cr,Ni主要来自工业和农业废水,铅来自采矿业和天然来源,Mn和Cd主要来自尾矿及其垃圾渗滤液。Basommatophora和Araneae可以用作地表水中重金属污染的潜在指示生物,和Basommatophora,鞘翅目,半翅目,Araneae可作为表层沉积物重金属污染的指示物种。研究表明,黑河地表水和沉积物中的大型无脊椎动物群落特征对重金属具有敏感的响应,可用于评价内河重金属污染状况。
Long-term retention and accumulation of heavy metals in surface water and sediment pose a great threat to the sustainable development of aquatic ecosystems and human health. In this research, macrozoobenthos, and surface water and sediment heavy metal (Mn, Cr, Cu, Ni, Pb, Zn, Cd, and As) samples were collected from 23 sites in the upper and middle reaches of the Heihe River in the summers of 2019-2020. The interrelationships between heavy metals and macrozoobenthos were analyzed by Pearson correlation analysis and redundancy analysis (RDA), and the contamination level and potential ecological risk of the heavy metals in surface water and sediments were assessed by comprehensive pollution index (WQI), single potential ecological risk index ([Formula: see text]), and sediment quality guideline-quotient (SQG-Q), respectively. The results showed that the level of heavy metal pollution in the surface water of the Heihe River was extremely low, but the contents of Mn and Pb exceeded the third class of surface water environmental quality standards (GB 3838-2002). The spatial distribution of heavy metals in surface sediments were significantly different, and the average concentration of 8 heavy metals exceeded the background values of Gansu Province. Meanwhile, the pollution level of heavy metals in surface sediments was high pollution, and the ecological risk level was moderate risk. Combining [Formula: see text] and SQG-Q evaluations showed that Cd, Ni, and Cr were the main ecological risk factors. In addition, the distribution coefficients of Cr and Cd were low, indicating that Cr and Cd were easily released from the surface sediments, causing secondary pollution. In terms of the source of the heavy metals, Cu, As, Zn, Cr, and Ni mainly came from industrial and agricultural wastewaters, Pb was from the mining industry and natural sources, and Mn and Cd mainly came from tailings and their landfill leachate. Basommatophora and Araneae can be used as potential indicator organisms for heavy metal pollution in surface water, and Basommatophora, Coleoptera, Hemiptera, and Araneae can be used as indicator species for heavy metal pollution in surface sediments. The study showed that macroinvertebrate community characteristics had a sensitive response to heavy metals in the surface waters and sediments of the Heihe River, which can be used to evaluate the pollution status of heavy metals in inland rivers.