青海海北化工厂铬渣堆积场土壤铬污染状况研究

通过野外观测与室内分析相结合的方法,研究了青海海北化工厂铬矿堆渣场土壤铬污染状况。结果表明:渣场附近土壤受到严重的铬污染,其铬含量大幅度超出全国土壤铬含量和青海土壤铬环境背景值。随距离堆渣场距离的增大,土壤铬含量急剧降低。土壤铬含量与距离堆渣场的距离之间的关系均可用线性函数或幂函数来表示,幂函数优于线性函数。铬在土壤剖面中的分布呈现出上低下高的分布趋势,其分布特征与铬的独特的土壤化学特性和土壤水分运动有关。堆渣场附近土壤中铬具有很大的可迁移性,铬进入土壤后主要和土壤碳酸盐、有机质和氧化物相结合,有很大一部分存在于土壤溶液中,显著地改变了原有土壤中铬的形态分布。在对堆渣场土壤污染进行治理时必须综合考虑气候、土壤、地形因素及铬的土壤环境行为。

Study on the Soil Cr Pollution in Residue Piling Yard in Qinghai Province

Through field investigation and laboratory analysis,we studied the soil Cr pollution in residue piling yard in Qinghai Province.The results showed that the soil around the residue piling yard was seriously polluted by Cr.Soil Cr content was increased greatly compared with that in Chinese soil,background value of soil environment in Qinghai.With the increase of the distance from residue piling yard,soil Cr content was decreased dramatically.Besides,the relationship between soil Cr content and the distance can be well described by linear and power function,however,power function was better than linear function.The content of Cr in soil profile was lower in upper soil and higher in lower soil,this distribution pattern was related with the special soil chemical characteristics of Cr and with soil water movement in profile.The Cr in the studied soils is apt to transport.Most Cr from residue are combined with carbonate,organic matters,and oxides in soils,or existed in soil solutions,which significantly changed the distribution of Cr among soil components.Therefore,climatic,pedologic,topographic factors and environmental behavior of Cr in soils should be fully considered in the dealings of polluted soils around residue piling yard.