基于模糊数学的场地重金属污染风险综合评价

在传统土壤评价方法的理论基础上,参考模糊数学的架构,建立了由风险因素集、风险评价集、隶属度函数、评估矩阵和权重系数组成的评价模型,最终形成了一套场地重金属污染风险的综合评价方法.选取安徽铜陵某冶炼厂作为研究场地,分析场地土壤中重金属的污染情况并验证该评价模型的科学性.结果表明,研究场地内表层土壤重金属含量平均值分别为As(1382mg/kg)、Cd(64.9mg/kg)、Cu(4973mg/kg)、Pb(3403mg/kg),As和Pb污染严重.相比于传统土壤评价方法,综合评价方法考虑重金属的人体健康风险、地下水迁移风险和生态风险3个方面,插值后不同风险所占面积比例为安全(25.3%)、低风险(5.86%)、中风险(9.00%)、高风险(59.9%).与内梅罗指数法对比,综合评价风险结果中的高风险区域面积下降了9.50%,而中风险、低风险和安全区域的面积则分别上升了约3.54%、3.83%和1.20%,整体风险有所降低.与传统土壤评价方法对比,基于模糊数学模型的综合评价方法不局限于重金属总量单一因素对土壤污染风险水平的限制,根据场地实际情况及土地二次利用途径对其进行更加详细的污染风险评...

Comprehensive assessment method of site heavy metal pollution risk based on fuzzy mathematics

Based on the theory of traditional soil evaluation methods and the framework of fuzzy mathematics, this paper established an evaluation model composed of risk factor set, risk evaluation set, membership function, evaluation matrix and weight coefficient, and finally formed a set of comprehensive evaluation methods for heavy metal pollution risk of sites. The polluted soil of a smelter from Tongling, Anhui was selected as the research site to analyze the pollution of heavy metals and verify the effectiveness of the evaluation model. The average contents of heavy metals in the surface soil of the study site were 1382mg/kg for As, 64.9mg/kg for Cd, 4973mg/kg for Cu, and 3403mg/kg for Pb. Among them As and Pb were seriously polluted. Compared to the traditional soil evaluation method, the integrated evaluation method considered three aspects especially human health risk, groundwater migration risk and ecological risk of heavy metals. The proportion of area occupied by different risks after interpolation was safe (25.3%), low risk (5.86%), medium risk (9.00%) and high risk (59.9%). Compared with nemero index method, the area of high risk in the comprehensive evaluation method decreased by 9.50%, while the area of medium risk, low risk and safe area increased by about 3.54%, 3.83% and 1.20% respectively, indicating that the overall risk decreased. Compared with traditional soil evaluation methods, the comprehensive evaluation method based on fuzzy mathematical model is not limited to a single index of total heavy metals, but carries out a more detailed pollution risk assessment regarding the actual situation of the site and the way of land reuse, which highlights the contribution of different heavy metal pollution and thus providing more accurate risk assessment of soil pollution.