【摘要】 以四川某矿山周边农田土壤为研究对象,测定表层土壤样品磁化率和Cu、Cr、Ni、Zn、Pb、Cd、As、Hg 8种元素的含量,探讨土壤磁化率与重金属等的相关性及空间分布规律。结果表明:与农用地土壤污染风险管控标准相比,除Hg外,其他7种元素均有不同程度的超标,以Cd、Cu超标最严重,超标率分别达到98. 9%和38. 7%;低频磁化率(χ_lf)和频率磁化率(χ_fd)的均值分别为175×10^-8m³/kg和5. 2%,其中旱地土壤的低频磁化率(χ_lf)与重金属Cu、Ni、Zn、Pb、Cd的含量呈显著正相关,水田土壤磁化率与重金属的相关性不明显,表明旱地土壤磁化率能更好地指示土壤重金属污染;土壤低频磁化率(χ_lf)与重金属含量和污染负荷指数（PLI）有着相似的空间分布,高值区集中在研究区中东部、东南部和北部地区,而频率磁化率(χ_fd)与低频磁化率(χ_lf)的分布趋势相反。土壤磁化率能够较好地指示农田土壤重金属的污染程度,可以作为土壤重金属污染研究的辅助手段。更多还原

【Abstract】 The magnetic susceptibility and the concentrations of Cu,Cr,Ni,Zn,Pb,Cd,As and Hg in farmland topsoil samples from the surroundings of mine in Sichuan Province were measured to investigate their spatial distribution and correlation in this study. The results showed that except Hg,the concentrations of other measured heavy metals were higher than the risk control standard for soil contamination of agricultural land. The exceed ratio of Cd and Cu was separately 98. 9% and 38. 7%. The average of low-frequency magnetic susceptibility and frequency magnetic susceptibility in topsoil samples was 175× 10^-8 m³/kg and 5. 2% respectively. Low-frequency magnetic susceptibility in dryland soil was significantly positively correlated with Cu,Ni Zn,Pb and Cd. However,there was no significant correlation between frequency magnetic susceptibility and the heavy metals in paddy soil. Therefore,the magnetic susceptibility in dryland soil could indicate soil heavy metal pollution better. The spatial distribution of the low-frequency magnetic susceptibility showed the same tendency with the spatial distribution of the heavy metals and the pollution load index. The high values of them were concentrated in the central eastern,southeastern and northern part of the study area. While the distribution of frequency magnetic susceptibility had the opposite tendency with the distribution of low-frequency magnetic susceptibility. Therefore,soil magnetic susceptibility can help indicating the pollution level of heavy metals in agricultural soil and can be used as an effective supplementary mean for the pollution research of heavy metal in soil.更多还原