• 关键词：黄土  污泥  Cd  再分配  形态

• 基金项目：国家自然科学基金(No.51178209,91025015);兰州大学中央高校基本科研业务费专项资金项目(No.lzujbky-2014-279,lzujbky-2014-208)

• 刘冲
• 兰州大学资源环境学院, 兰州 730000

• 李虎
• 兰州大学资源环境学院, 兰州 730000

• 赵一莎
• 兰州大学资源环境学院, 兰州 730000

• 武文飞
• 兰州大学资源环境学院, 兰州 730000

• 王厚成
• 兰州大学资源环境学院, 兰州 730000

• 南忠仁
• 兰州大学资源环境学院, 兰州 730000

• 摘要：以黄土和小麦为供试对象,通过盆栽试验研究了不同胁迫水平Cd在施用污泥黄土中的形态分布特征及其再分配.结果表明,原状土壤中Cd以碳酸盐结合态及残渣态为主要赋存形态.随着外源Cd添加量的增加,土壤中可交换态和碳酸盐结合态Cd分配系数持续增加,而有机态与残渣态分配系数则持续减小,土壤Cd的主要赋存形态转变为可交换态和碳酸盐结合态,Cd的活性不断增强,加大了对作物的潜在危害.土壤中碳酸盐结合态Cd含量随Cd胁迫水平的增加而增加的幅度最大,施用污泥黄土中铁锰氧化态Cd含量随Cd胁迫水平的增加而增加的幅度高于可交换态Cd;黄土与施用污泥黄土中Cd的总再分配系数均随Cd胁迫水平的增加呈递增趋势,而结合强度系数均随Cd胁迫水平的增加呈递减趋势.污泥的施用可增加土壤中残渣态Cd的含量,有助于提高Cd各形态间再分配的稳定性,相对降低了土壤Cd的活性.

• Abstract：A field pot experiment was conducted for loess and wheat to study the speciation distribution and redistribution of Cd in loess amended with sewage sludge. The results indicated that carbonate bounded and residual forms were the main chemical speciations of Cd in undisturbed soil. With the increasing concentrations of exogenous cadmium, exchangeable and carbonate bounded Cd continued to increase while the organically bound and residual Cd decreased. The main chemical speciations of Cd in soil were converted to exchangeable and carbonate bounded Cd. The potential hazard of Cd to loess-wheat system was aggravated for the increase of activity coefficient of Cd. Carbonate bounded Cd content in soil increased greatly with the increase of stress levels. The increase rate of Fe-Mn oxidation Cd in soil amended with sludge was higher than exchangeable Cd. The total redistribution coefficient in loess and loess amended with sludge increased while the reduced partitioning parameter of Cd decreased with increasing stress levels. The application of sewage sludge increased residual Cd content in soil and improved redistribution stability of Cd and inhibited activity of Cd in soil.

• Key words：loess  sludge  cadmium  redistribution  speciation

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