重金属污染黏性土电阻率影响因素分析及其预测模型

Impact factor analysis of resistivity of heavy metal polluted cohesive soil and its prediction model

采用改进的电阻率测试设备,对3种室内人工配制的重金属(Zn,Pb,Cd)污染黏性土进行正交试验研究.探讨了4种因素(污染物掺量N、孔隙湿密度md、体积含水量Pr和污染种类S)对重金属污染黏性土电阻率的影响.结果表明:重金属污染黏性土电阻率随孔隙湿密度和体积含水量的增大呈指数函数减小,随污染物掺量的增大而减小,并且相同离子化合价的重金属离子对土体电阻率的影响规律基本一致.方差法和极差法分析表明,4种影响因素对重金属污染黏性土电阻率的影响程度不同,其影响程度大小依次为:N,m_d,P_r,S.此外,为将Archie电阻率预测模型的应用范围进行拓展,建立了适用于重金属污染黏性土的电阻率预测模型.该电阻率预测模型可以用于特定区域重金属污染场地的定量评价.

The improved resistivity test equipment was used to explore the heavy metal polluted cohesive soil by an orthogonal experiment. The polluted soil samples were prepared with three kinds of indoor artificial heavy metals（ Zn,Pb,Cd）. The impacts of four factors（ pollution concentration N,moisture density md,volumetric water content Pr,and pollution type S） on the resistivity of the heavy metal polluted soil were discussed. The results showthat the resistivity of the heavy metal polluted soil decreases exponentially with the increase of the moisture density and the volumetric water content. The resistivity decreases with the increase of the pollution concentration. The heavy metal ions with similar ion valence have the same effects on the soil resistivity. The analysis results of the variance method and the range method showthat the four factors have different influences on the resistivity of the heavy metal polluted soil. The order of the impact degree is N,m_d,P-r,S. In addition,the prediction model for the resistivity of heavy metal polluted cohesive soil is established to extend the application range of Archie＇s model. The resistivity prediction model can be used to quantitatively evaluate the heavy metal polluted sites in a specific region.