工矿企业周边沟渠底泥重金属污染特征与风险评价  

Characteristics and risk assessments of heavy metals pollution of sediment within ditches around industrial and mining enterprises

作　　者：谢可军 王建伟 方建林[3] 朱捍华[2] 黄道友[2] XIE Ke-jun;WANG Jian-wei;FANG Jian-lin;ZHU Han-hua;HUANG Dao-you(Hunan Ecological and environmental Affairs Center,Changsha,Hunan 410014,China;Key Laboratory of Agro-Ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha,Hunan 410125,China;Xiangtan Agricultural Science Research Institute,Xiangtan,Hunan 411100,China)

机构地区：[1]湖南省生态环境事务中心,湖南长沙410014 [2]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,湖南长沙410125 [3]湘潭市农业科学研究所,湖南湘潭411100

出　　处：《农业现代化研究》2024年第4期711-722,共12页Research of Agricultural Modernization

基　　金：国家重点研发计划项目(2022YFC3704802)。

摘　　要：工矿企业为重金属排放重点行业,系统研究其周边沟渠底泥重金属污染特征与风险具有重要意义。本研究以典型涉重金属排放化工企业周边区域为对象,系统调查监测了沟渠底泥、水体以及周边耕地土壤重金属含量,分析了沟渠底泥重金属污染特征与生态风险,评估其对水体、周边耕地土壤重金属污染的影响及范围。结果表明,沟渠底泥、水体和耕地土壤中主要重金属污染元素为Cd,其平均含量分别为16.61 mg/kg、5.20μg/L和1.22 mg/kg,其中底泥和耕地土壤Cd平均含量约为湖南省土壤背景值的195和14倍。沟渠底泥和水体中Cd含量相关性系数达到0.84,均随水流方向总体呈递减趋势;以漫灌方式灌溉的沟渠下游耕地土壤Cd含量整体更高,推测沟渠受污染底泥为水体和耕地土壤重金属污染的“源”。风险评价显示,沟渠底泥中Cd呈极高累积风险和重度潜在风险;受底泥重金属影响,水体中Cd和Hg呈重度污染风险,耕地土壤Cd呈中度累积风险,Hg和Pb为轻度累积风险。沟渠底泥重金属污染主要影响沟渠两侧及下游海拔低于46 m的耕地,面积约569 hm2。本研究为工矿企业周边受重金属污染耕地的源头防控和精准治理提供理论依据。Industrial and mining enterprises are key sources of heavy metal discharges,making it crucial to systematically study the characteristics and risks of heavy metal pollution in the sediments of surrounding ditches.This study investigated and monitored heavy metal concentrations in the ditch sediments,water,and adjacent cultivated soil around a typical chemical enterprise involved in heavy metal emissions.The characteristics and ecological risks of heavy metals in the ditch sediments were analyzed,and the influence and extent of heavy metal pollution on ditch water and surrounding cultivated soil were evaluated.The results showed that the main heavy metal pollutant was Cd,with average concentrations of 16.61 mg/kg in sediments,5.20µg/L in water,and 1.22 mg/kg in cultivated soil.The average Cd content in sediments and cultivated soils was approximately 195 and 14 times the background value for soil in Hunan Province,respectively.The Cd concentrations in the sediments and water decreased linearly along the flow direction,with a correlation coefficient of 0.84 between the two media.Additionally,Cd levels were higher in the downstream cultivated soils irrigated by the ditch,indicating that the polluted sediments were the primary source of heavy metals in the water and cultivated soil.Risk assessments revealed that Cd in the sediments posed a high cumulative risk and severe potential risk.Due to the influence of heavy metals in the sediments,the water was presented with serious pollution risks of Cd and Hg,while the cultivated soil was moderately polluted with Cd and slightly polluted with Hg and Pb.The heavy metal pollution in the ditch sediments and water primarily affected cultivated land at altitudes lower than 46 meters around and downstream of the ditch,covering an area of about 569 hectares.This study provides a theoretical basis for source prevention and control,and targeted remediation of heavy metal-contaminated cultivated soil around industrial and mining enterprises.

关 键 词：重金属污染 沟渠底泥 地表水 耕地土壤 污染特征 风险评价 影响范围 

分 类 号：X53[环境科学与工程—环境工程]