黄河干流甘肃白银-宁夏沙坡头段水体污染现状评价及源解析OA北大核心CHSSCDCSTPCD

69 groups of water samples were collected for investigation on concentration of As,Cu,Cd,Zn,Pb and Mn to expose the pollution status in the mainstream of the Yellow River,from Baiyin City in Gansu Province to Shapotou City in Ningxia Hui Autonomous Region.Heavy metal pollution index,Nemero index and potential ecological risk assessment model were employed to evaluate the pollution characteristics and potential ecological risk in this stream section,and pol-lutant sources were also analyzed based on the distribution of industrial and agricultural activities by Pearson correlation a-nalysis and principal component analysis.The results show that Class Ⅱ criteria of national surface water quality standard was matched by As,Cu,Cd,Zn and Pb but exceeded by Mn component with increasing tendency of all heavy metal con-tent along the river,and high content samples were mostly found in or near the tributaries confluence.The assessment re-sults demonstrate that pollution level of this river section is very slight pollution level by heavy metal pollution index,rela-tively clean to heavy pollution level by Nemero index and slight ecological risk level by both single and multi-element com-prehensive potential ecological risk index.As,Cu and Mn pollutants are recognized as mainly composite pollutants from in-dustrial and natural sources,Cd and Pb are mainly influenced by the combination of agricultural and industrial activities,and Zn is mainly from traffic source.Human activity is the key factor affecting the water quality in the study area.