外源铬在土壤中的形态转化  

Transformations of fortified Cr in soils

作　　者：陈英旭[1] 何增耀[1] 吴建平 沈东升[1] 张君 王珂 

机构地区：[1]浙江农业大学环保系

出　　处：《农业环境保护》1995年第3期105-110,共6页Agro-Environmental Protection

摘　　要：本试验用逐级提取方法，研究了外源铬进入土壤后的形态转化，结果表明：添加到土壤小的Ｃｒ（Ⅵ）很快还以为Ｃｒ（Ⅲ）而失去其活动性，水溶态和交换态铬含量在培育６周后已恢复到对照水平，添加的Ｃｒ（Ⅲ）很快被土壤吸附和沉淀而固定，难以被Ｈ＿２Ｏ和ＮＨ＿４Ａｃ提取。添加的有机结合态铬能显著提高土壤中水溶态和交换态铬含量，并能在较长时间内稳定存在于土壤中，添加污泥形式的铬进入土壤主要以残渣态、沉淀态和有机紧结合态铬为主。Abstract Cr(Ⅵ)add to soil was rapidly reduced into Cr(Ⅲ)and then convertedinto less mobile precipitation and organic-bound Cr。Cr(Ⅲ)add to soils wasrapidly absorbed and precipitated,and then converted gradually into organic-bound and residual Cr as incubation time increased。Treatment with Cr(Ⅲ)raised Cr(Ⅲ)solubility in soils following the order of EPTA-Cr>citric-Cr>fulvic-Cr>humic-Cr. Organic complexed Cr(Ⅲ)might exist in a long per-iod in soil solution, because it could not easily adsorbed and precipitatedby soils.Sludge-amended soil contained very little watersoluble and NH_4Acextractable Cr. Residues,precipitation and organic-bound Cr predominatedin the soil, together accounting for about 99%or even more of the totalCr. In the incubation process, residual Cr became Organic-bound and preci-pitated gradually.

关 键 词：铬 形态转化 环境土壤学 

分 类 号：X144[环境科学与工程—环境科学]