武陟农田重金属污染特征及其与河流底泥的关联性分析

Analysis of the Characteristics of Heavy Metal Pollution in Wuzhi Farmland and Its Correlation with River Sediments

通过对武陟研究区农田土壤和河流底泥中As、Cd、Cu、Ni含量进行测定,并采用单因子污染指数法、内梅罗综合污染指数法、潜在生态风险指数法分析其污染特征,对农田土壤与支流1和支流2底泥重金属含量之间的关联性进行分析。结果表明,Cd的积累效应最明显,As、Ni的积累效应次之,Cu的积累效应不明显;As和Cd含量的高值区主要分布在支流1和支流2附近,Ni含量的高值区主要分布在靠近支流1的养殖场附近,Cu含量的高值区主要分布在支流1附近。Cd的单因子污染指数均值为8.70,属于重污染程度;Cu和Ni所引起的污染处于清洁水平;As含量处于警戒水平;Cd的综合潜在生态风险指数的贡献率97%。农田中Cd与As之间存在同源污染,底泥中的Cd和As也有同源性;农田土壤的Cd、As与底泥中对应重金属的关联性最明显;土壤重金属Cu和Ni与支流1底泥有关联性、Ni还受养殖场的影响。

By measuring the content of As,Cd,Cu,and Ni in the farmland soil and river sediment in the Wuzhi research area,and the single-factor pollution index method,Nemero comprehensive pollution index method and potential ecological risk index method were used to analyze the pollution characteristics,the correlation between the contents of heavy metals in farmland soils and tributary 1 and tributary 2 sediments was analyzed.The results showed that the accumulation effect of Cd was the most obvious,followed by that of As and Ni,and the accumulation effect of Cu was not obvious.The high value areas of As and Cd were mainly distributed near tributary 1 and tributary 2,the high value areas of Ni were mainly distributed near the farm near tributary 1,and the high value areas of Cu were mainly distributed near tributary 1.The mean value of single factor pollution index of Cd was 8.70,which belonged to the degree of heavy pollution.The pollution caused by Cu and Ni were at a clean level;As content was at the alert level.The contribution of the combined potential ecological risk index of heavy metals for Cd was 97%.There was homologous contamination between Cd and As in agricultural fields,and Cd and As in substrates.The correlation between Cd and As in agricultural soils and the corresponding heavy metals in substrates was most obvious;soil heavy metals Cu and Ni were correlated with tributary 1 substrates,and Ni was also influenced by farms.