川渝地区中小河流沉积物污染现状分析及影响评价——以重庆市临江河永川城区段为例  

Current Situation Analysis and Impact Assessment of Sediment Pollution in Small and Medium-Sized Rivers in Sichuan-Chongqing Region:a Case Study of Yongchuan Urban Section of Linjiang River in Chongqing

作　　者：迟明慧 刘志超[1] CHI Minghui;LIU Zhichao(Institute of Water Ecology and Environment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]中国环境科学研究院水生态环境研究所,北京100012

出　　处：《防化研究》2024年第3期47-55,共9页CBRN DEFENSE

摘　　要：本研究以川渝地区的典型小流域——临江河永川城区段为研究区,通过分析14个采样点的沉积物中总氮、总磷、有机质和关键重金属[铜(Cu)、锌(Zn)、铅(Pb)、铬(Cr)、镉(Cd)和砷(As)]的质量比/质量分数及空间分布情况,采用有机污染指数法评价总氮、总磷和有机质风险,采用地累积指数法和潜在生态风险指数法评价重金属污染程度及其潜在生态风险,研究其对该区域水生态环境的影响。结果表明,在有机污染方面,临江河永川城区段沉积物中的有机质为主要超标因子,平均质量分数为8.70%;沉积物有机污染指数均值为0.65,处于IV级,有机污染较严重。在重金属污染方面,临江河永川城区段沉积物中Cu、Zn、Pb、Cr、Cd、As6种重金属的平均质量比分别为59.89、98.24、28.58、36.33、1.42、5.23 mg·kg^(-1);与重庆市土壤背景值比较,Cd超标最为严重。综合评价结果显示,临江河永川城区段沉积物处于高风险状态,其中Cd为最主要的污染元素,生态风险等级较高。In this study,the urban section of Linjiang River in Yongchuan,a typical small watershed in Sichuan-Chongqing region,was selected as the research area.The mass ratio/mass fraction and spatial distribution of total nitrogen,total phosphorus,organic matter and six key heavy metals(Cu,Zn,Pb,Cr,Cd and As)in sediment from 14 sampling sites were analyzed.The organic pollution index method was applied to assess the risks of total nitrogen,total phosphorus and organic matter.Meanwhile,the Index of Geoaccumulation(Igeo)method and Potential Ecological Risk Index(RI)method were applied to assess the degree of heavy metal pollution and potential ecological risks and study their impact on the water ecological environment.The results illustrated that organic matter was the main exceeding factor,with an average content of 8.70%.The average organic pollution index of the sediment was 0.65,which could be classified as Class IV and indicated severe organic pollution in this area.At the same time,the average mass ratio of six heavy metals(Cu,Zn,Pb,Cr,Cd and As)in the sediment of the study area were 59.89 mg·kg^(-1),98.24 mg·kg^(-1),28.58 mg·kg^(-1),36.33 mg·kg^(-1),-11.42 mg·kg and 5.23 mg·kg^(-1),respectively.Compared with the soil background value in Chongqing,Cd exceeded the standard most seriously.The results of Igeo and RI assessment showed that the sediment in the urban section of Linjiang River was in a high-risk state,among which Cd was the most important pollutant element,and the ecological risk level was relatively high.

关 键 词：沉积物 营养盐 重金属 风险评价 临江河永川城区段 

分 类 号：X522[环境科学与工程—环境工程]