施用10年猪粪肥的黄壤剖面重金属分布及风险评价

为了解施用10年猪粪肥后土壤剖面重金属分布情况及生态风险,以贵州喀斯特地区施用10年猪粪肥的黄壤剖面为研究对象,分析茶园和耕地土壤的重金属剖面分布,采用内梅罗(Nemerow)综合污染指数法和Hakanson潜在生态危害指数法对土壤环境质量及潜在风险进行了评价。结果表明,施用10年猪粪肥的耕地和茶园表层土壤中Cd、Cr、Pb、As、Cu和Zn质量比均高于未施用猪粪肥的表层土壤。重金属Cd、Cu、Zn表层聚集现象明显,质量比随剖面深度增加而降低;重金属Cr、Pb、As表层聚集现象不明显,质量比随剖面加深变化不大。内梅罗综合污染指数法评价结果表明,施用10年猪粪肥的茶园和耕地土壤表层(0~20 cm)综合污染指数分别为0.72、0.71,污染等级达到警戒线(0.7P综≤1.0)。Hakanson潜在生态危害指数法评价结果表明,施用10年猪粪肥的茶园和耕地土壤剖面的生态风险危害程度为轻微污染(RI150)。施用10年猪粪肥的土壤表层(0~20cm)出现重金属Cd、Cu、Zn的聚集,重金属污染等级达到警戒线,土壤存在安全隐患。

Analysis of the heavy metal risk content rate through the vertical profile of the yellow soil a decade late due to the swine manure application

The aim of this paper is to analyze and identify the vertical distribution features and explore the ecological risks of heavy metal content rate in the yellow soil for a decade application of swine manure. According to the survey and analysis,we have chosen the profiles of tea plantation and arable land in Guizhou karst region as the research objective,which has been applied to with the swine manure for about a decade long. For the said research objective,we have measured and determinated the content rates of the heavy metals in the soil profile. And,in turn,we have analyzed and evaluated the soil environmental quality through Nemerow comprehensive pollution index and Hakanson potential ecological hazard index so as to find the potential safety risks. The results of our investigation show that the content rates of Cd,Cr,Pb,As,Cu,and Zn in the surface soil (0-20 cm) affected by the swine manure turn out to be higher than those with no application of that manure. As to the deeper layer of the soil, the content rates of Cd,Cu,and Zn in it turn out decreasing significantly, which suggests an obvious accumulation of the above mentioned heavy metal residence on the surface of the soil. In spite of this,in the deeper layers of the soil,no obvious decrease of the pollution rates of Cr,Pb in all the said soil profiles. What is more,the evaluation of Nemerow comprehensive pollution index, the soil surface (0-20 cm) pollution index of the tea plantation and arable land remain still 0. 72 and 0. 71,respectively, implying that such items of pollution are also close to the warning line (Nemerow comprehensive pollution index evaluation indicate that the warning line is between 0. 70 and 1. 0). Moreover,the assessment result of Hakanson potential ecological hazard index still indicates that the soil suffering from the swine manure application can be said slightly polluted (RI ＜ 150). Thus,it can be summed up that heavy metals,especially,Cd,Cu,and Zn,are prone to be gathered and accumulated at the surface soil (0-20 cm). Besides,the investigation results gained by using the two evaluation methods verify that the heavy metal contents in the soil have been found obvious,which can be a potential safety hazard as the decade result of its application.