污染损失率法在土壤重金属污染评价中的应用

Application of comprehensive pollution loss rate to pollution assessment of soil heavy metals

利用土壤环境质量评价的一种新评价理论污染损失率法对陕西省泾惠渠灌区的土壤质量进了评价。评价结果表明,21个土壤采样点综合污染损失率在9.10%～16.15%之间,占总土壤采样点数的87.5%,污染等级为Ⅱ级,土壤属于尚清洁水平;两个土壤采样点属于轻污染水平;只有一个样点污染等级为Ⅳ级,属中污染水平。结果与实际情况较吻合。同时应用传统的内梅罗法综合指数法进行了验证性评价。各样点两种评价方法的污染程度排序结果除3个样点的污染排序次序差异较大外,其他样点的次序基本一致。通过对综合污染损失率与内梅罗综合污染指数(P)及潜在生态风险指数(RI)的相关性分析,相关系数分别为0.9788和0.9203,都达到了极显著相关(p﹤0.01),说明综合污染损失率法的评价结果是可靠的。将污染损失率法应用于土壤环境质量评价中,对样本中超标较严重的污染因子有更强的分辨率,对于土壤污染的相对严重性判断更精确,可以为相关管理部门提供明确的决策信息,从而针对不同的土壤重金属超标情况采取相应的控制和修复措施。

Soil quality of Jinghuiqu irrigation district of Shaanxi province was evaluated by using a new evaluation theory of pollution loss rate.The results show that comprehensive pollution loss rate is among 9.10%~16.15% at 21 soil sampling sites,which is accounting for 87.5% of the total soil sampling sites.Pollution grade is Ⅱ level,and soil belongs to clear level.Soils in two soil sampling sites belong to light pollution level,and only one site is middle pollution level.This conclusion is reasonably in accordance with the practical situation.At the same time the verification evaluation is proceeding by traditional Nemerow integrated index method.Pollution degree ranks are basically consistent between Nemerow integrated index and comprehensive pollution loss rate in every site,except for three sampling sites.The correlation analysis results show that comprehensive pollution loss rate has a very significant relation with Nemerow comprehensive pollution index（P） and potential ecological risk index（RI）,and correlation coefficient are 0.9788 and 0.9203（p﹤0.01）,respectively.It means evaluation result of comprehensive pollution loss rate is reliable.While pollution loss rate is used in evaluation of soil environmental quality,it has more strong resolution for pollution factors that exceed standard seriously,and the judgment for soil pollution degree is more precise.A clear decision information can be provided for relevant management departments,which can take control and repair measures according to different situation that soil heavy metal exceeds standard.