【摘要】 以山东省淄博市高青县的设施农地为研究对象,分析表层土壤(0～20 cm)的酸碱度(pH)、有机质以及重金属Zn、Cr、Cd、Ni含量和形态,同时采用单因子指数法、内梅罗综合污染指数法、地质累积指数法、潜在生态危害指数法对土壤质量现状进行评价。结果表明:(1)高青县设施农田表层土壤样品中重金属Cr、Ni、Zn、Cd的平均含量分别为91.16、33.27、34.82、1.34 mg/kg,其中重金属Cr、Ni、Cd均超过淄博市土壤重金属环境背景值,土壤有机质含量介于14.75～33.88 g/kg之间,pH值介于5.17～8.51之间;(2)可氧化态和残渣态是设施农田土壤中重金属Cr、Ni、Zn、Cd的主要存在形态,重金属Cr、Ni、Zn的不同形态含量从大到小排序均为残渣态>可氧化态>可还原态>可交换态,而重金属Cd形态含量从大到小排序为残渣态>可氧化态>可交换态>可还原态;(3)相关性分析可知,高青县设施农田土壤中有机质仅对重金属Zn含量产生影响,而对其他研究元素无明显影响,且Cr与Cd之间及Cr、Ni、Zn之间均具有一定的同源特性,除了pH值对Ni的可交换态迁移转化产生较显著影响外,土壤有机质和pH值对其他所有重金属形态无显著影响;(4)四种指数法的评价结果均表明高青县设施农田土壤整体处于重金属Cd重度污染状态,重金属Cd是构成生态危害的主要风险因子。更多还原

【Abstract】 Taking the greenhouse farmland in Gaoqing County, Zibo City, Shandong Province as the research object, the pH, organic matter, Zn, Cr, Cd, Ni content and form of surface soil(0 ～ 20 cm) were analyzed, and the single factor index method, nemero comprehensive pollution index method, geological accumulation index method and potential ecological hazard index method were used to evaluate the current situation of soil quality. The results show that:(1) The average contents of heavy metals Cr, Ni, Zn and Cd in surface soil samples of greenhouse farmland in Gaoqing county are 91.16, 33.27, 34.82 and 1.34 mg/kg, respectively, and the contents of heavy metals such as Cr, Ni and Cd are all higher than the background values in Zibo City. Soil organic matter content ranged from 14.75 to 33.88 g/kg and pH from 5.17 to 8.51.(2) The main forms of heavy metals such as Cr, Ni, Zn and Cd are oxidizable and residue states. The content order of each form is residue state> oxidizable state> reducible state> exchangeable state, except that the order for Cd forms is residue state>oxidizable state>exchangeable state> reducible state.(3) Correlation analysis shows that organic matter only affected the content of heavy metal Zn in the soil, and had no obvious effect on other elements. Cd had certain homologous features,so did Cr, Ni and Zn. pH value significantly influences migration of Ni,but soil organic matter and pH have no significant effect on all other forms of heavy metals.(4) The results of above four index methods show that the heavy metal Cd was the key factor for the soil pollution and potential ecological risk of greenhouse farmland in Gaoqing County.更多还原