【作者】 吴涛；

【导师】 曾英； 桑世华；

【作者基本信息】 成都理工大学 ， 分析化学， 2005， 硕士

【摘要】 土壤所含镉可对环境和人体健康造成危害。对土壤所含镉的环境化学行为进行研究,有助于防治或减轻这种危害。 本文针对成都市表生土壤中镉的环境化学行为进行研究,包括以下研究内容:成都市表生土壤的镉污染状况调查;表生土壤中镉的化学形态研究;土壤性状同土壤镉赋存形态的关系研究;土壤淋滤实验研究。 研究结果表明:成都市表生土壤样中有42.86%受镉污染,镉综合污染水平达中度污染,成都市表生土壤镉污染程度与采样点周围环境表现出一定的相关性;除铁锰氧化物结合态镉在部分土壤样中未检出外,所有土壤样均含有可交换态镉、碳酸盐结合态镉、有机结合态镉、残留态镉,且生物有效性较高的可交换态镉和碳酸盐结合态镉占总镉量比例较高;成都市表生土壤中的腐殖质与可交换态镉、有机结合态镉、残留态镉有一定相关性,与碳酸盐结合态镉、铁锰氧化物结合态镉相关性不显著;各形态镉与土壤pH值和全铁的相关性均不显著;土壤中的镉可被酸溶液淋出,重蒸馏水淋出镉量十分微小;随着淋滤液pH值的升高,土壤样的镉淋出量下降,且0～5小时时段的镉淋出量占镉总淋出量比例下降,5～30小时时段的镉淋出量占镉总淋出量的比例上升,对同一土壤样而言,酸度大的淋滤液比酸度小的淋滤液淋出镉速度更快,淋出镉量更大。更多还原

【Abstract】 Cadmium in soil is harmful to environment and human health. Study on environmental chemical action of Cadmium in soil is helpful to prevent and eliminate the harm.Environmental chemical action of Cadmium in topsoil in Chengdu has been studied in this paper, including the Cadmium pollution survey of topsoil in Chengdu, the chemical speciation research of Cadmium in topsoil, the research of correlation between soil character and chemical speciation of Cadmium and eluviating experiment research.The results show that 42.86% topsoil samples are polluted by Cadmium, soil synthesis pollution index is moderate, Cadmium pollution degree of topsoil correlate with the environment of sampling sites. The results also show that exchangeable Cd, carbonate-bound Cd, organic-bound Cd and residual Cd are found in all soil samples except for Fe-Mn oxide-bound Cd. Furthermore, the concentration of exchangeable Cd and carbonate-bound Cd, both which have high biological validity, is high. Humus has a certain correlation with exchangeable Cd, organic-bound Cd and residual Cd, and has no obvious correlation with other chemical speciations. Any chemical speciation of Cd has no obvious correlation with pH and total Fe of soil samples. Cadmium in topsoil can be eluviated by acid solution, the quantity of Cadmium eluviated by redistilled water is little. With the rise of pH of eluviating solution, eluviated Cadmium quantity decrease. For the same soil sample, the lower pH value of eluviating solution is, the more fast the Cadmium is eluviated, and the more thequantity of Cadmium is eluviated.更多还原