碧流河下游农田土壤重金属污染状况分析与评价

Analysis and evaluation of heavy metal pollution in farmland soils in the lower reaches of Biliuhe River

为给碧流河下游农田土壤的可持续利用提供参考依据,基于实验测试数据,采用单因子污染指数法、内梅罗综合污染指数法及潜在生态危害指数法,对碧流河下游水貂养殖区的农田土壤重金属污染状况进行分析评价。结果表明:碧流河下游农田土壤重金属元素Cr、Ni、Zn、Cu、As和Pd含量的平均值均超出辽宁省土壤背景值;6种重金属元素的单因子污染指数依次为Ni>Zn>Cu>Cr>As>Pd;农田土壤重金属内梅罗综合污染指数为3.99,农田土壤整体处于重污染水平;6种重金属元素的潜在生态危害指数依次为Ni>As>Cu>Pd>Zn>Cr,潜在生态危害综合指数为49.4—196.6,平均值为132.6,农田土壤整体表现为轻微生态危害。农田土壤中Ni、Cr和Cu的累积可能主要来源于碧流河流域的工、农业排放物和水貂养殖业貂笼清除物,Pd的累积可能主要来源于沿岸居民倾倒和焚烧的生活垃圾,以及不合理的农业经营活动。

To provide reference data for the sustainable utilization of farmland soil in the lower reaches of Biliuhe River,the single factor pollution index method,Nemero comprehensive pollution index method and potential ecological hazard index method were used based on experimental data to analyze and evaluate the heavy metal pollution status of farmland soil of mink farming areas in the lower reaches of Biliuhe River.Results showed that the average contents of heavy metal elements Cr,Ni,Zn,Cu,As and Pd in farmland soil of the lower reaches of Biliuhe River exceeded the soil background values of Liaoning Province.The single factor pollution indexes of6heavy mental elements were ranked as follows:Ni>Zn>Cu>Cr>As>Pd.The Nemero comprehensive pollution index of heavy metals in farmland soil was3.99.Therefore,farmland soil was heavily polluted on the whole.The potential ecological hazard indexes of6heavy metal elements were ranked as follows:Ni>As>Cu>Pd>Zn>Cr.The comprehensive index of potential ecological hazard varied from49.4to196.6,with an average value of132.6.Therefore,the overall ecological situation of farmland soil was slightly polluted.The accumulation of Ni,Cr and Cu in farmland soil might be mainly from industrial and agricultural emissions in the basin of Biliuhe River and cleanings of mink cages in the mink farming industry.The accumulation of Pd might be mainly from household garbage dumped and incinerated by residents along the bank of Biliuhe River and unreasonable agricultural business activities.