矿冶区重金属污染土壤肥力特征及生态修复潜力分析

通过对湖南长沙、株洲、衡阳和郴州地区典型矿冶区周边64个土壤样品的调查分析,结果表明,与我国《土壤环境质量标准》(GB15618-1995)III级标准(pH6.5～7.5)比较,典型矿冶区周边土壤中As、Cd、Pb和Zn含量的超标率分别为75.8%、75.8%、66.1%和71.0%,表现为多重金属污染。废弃地土壤中As、Cd、Cr、Cu、Pb和Zn含量显著高于菜地和水稻土壤中相应元素含量。典型矿冶区周边土壤整体呈酸性,质地较粘。土壤中有机质、碱解N、速效P、有效K含量范围分别为0.18～143g/kg、14.7～372、7.82～202、0.00～782mg/kg,其平均含量达到II级标准值的样品数分别占总样品数的93.7%、95.4%、100%和89.1%。土壤质地和肥力特征表明,典型矿冶区周边重金属污染土壤基本肥力总体水平较好,可以顺利开展其生态修复。

Fertility Characteristics and Ecological Restoration Potential Analysis for Metal Contaminated Soils from Vicinity of Typical Mining and Smelting Areas in Hunan Province

64 soil samples from vicinity of typical non-ferrous mining and smelting areas located in Changsha,Zhuzhou,Hengyang and Chenzhou,Hunan Province were studied.According to Grade III of pH 6.5～7.5 in GB15618-1995 Soil Environmental Quality Standard of China,results showed that over-limited percentages of As,Cd,Pb and Zn in soils are about 75.8%,75.8%,66.1% and 71.0% respectively,which show multi-metal pollution in soils.Concentrations of As,Cd,Cr,Cu,Pb and Zn in wasteland are significantly higher than those in vegetable soils and paddy soils respectively.The tested soils are mainly acidic with viscous soil texture.Concentrations of organic matter,available N,available P and available K are 0.18～143g/kg,14.7～372mg/kg,7.82～202mg/kg and 0.00～782mg/kg respectively,compared with Grade II of Soil Fertility Standard,the over-standard rates in the soil samples from the studied areas are 93.7%,95.4%,100% and 89.1% respectively.Results of the soil fertility and soil texture showed that ecological restoration for metal contaminated soils from the vicinity of the typical mining and smelting areas would be favorably carried out.