湘南锰矿废弃地重金属污染土壤的研究及评价

Research and Assessment on Heavy Metal Pollution in the Soil of Abandoned Mn Mines in Southern Hunan

采用地积累指数及Lars Hakanson潜在生态危害指数法对湘南锰矿废弃地重金属的生态危害进行评价与比较。结果表明矿区废弃地重金属污染严重,Cd的地积累指数均大于5,Mn、Pb、Cd 3种重金属为该地区产生生态危害的主要重金属,5种重金属元素污染顺序为Cd>Mn>Pb>Cu>Zn。多种重金属潜在生态危害指数表明,该地区重金属污染属于极强的生态危害。两种评价方法对比,潜在生态危害指数法略为保守,两者结合更具实际应用意义。从尾砂坝下游旱地的研究结果可知,采矿产生的废水已经污染到下游土地,在这些土地上种植的农作物可能受重金属污染,建议不要食用。

Geoaccumulation index （lgeo） and Lars Hakanson potential ecological harm index are used to evaluate and compare the ecological hazard of heavy metal on the soil of abandoned Mn mines in Southern Hunan and the results show that the heavy metal pollution at the soil of the abandoned Mn mines is serious, that the lgeo of both Mn and Cd is beyond 5, that Mn, Pb and Cd are main heavy metals for the hazard on production and ecology in this area, that the pollution order of the five metals is Cd〉Mn〉Pb〉Cu〉Zn, and that the potential ecological harm index of many heavy metals indicates that the heavy metal pollution in this area has extreme ecological hazard. Comparison of the two evaluation methods reveals that potential ecological harm index method is a little conservative and the combination of the two methods is of real significance. According to the research results of dry land at the downstream of Weisha Dam demonstrate that the waster water from the mining has polluted the land at the downstream and the crops planted in the land may be polluted by the heavy metals and the food from the crops should not be eaten.