牛粪-贝壳粉蚯蚓反应器中堆制物表征及其对Cd2+去除性能研究

    Study on the Characterization and the Removal Efficiency of Cd2+ by the Substrate Residues From Cow Dung-Shell Powder Vermireactors

    • 摘要: 土壤中镉(Cd)污染已引起广泛关注,以牛粪-贝壳蚯蚓反应器为研究对象,分析其堆制物性状变化规律及Cd2+去除特性。结果表明,贝壳粉及其改性物添加下蚯蚓可以较好地适应生长环境并正常生长繁殖。蚯蚓处理可降低堆制物pH值、C/N比以及脂类和多糖类物质含量,提高其阳离子交换量、比表面积、芳香类及醇或羧酸类有机物质含量、硅酸盐类和可溶性盐等无机组分含量。贝壳粉及其改性物添加均可提高堆制物的pH值、阳离子交换量及比表面积;贝壳粉添加增加了其CaCO3组分,而贝壳粉改性物添加则可增加其CaCO3、CaO、Ca(OH)2组分。吸附解吸试验表明,贝壳粉改性物添加下蚯蚓处理后堆制物对Cd2+的去除效果相对更好,去除率可达59.9%。因此,于牛粪蚯蚓反应器中添加贝壳粉改性物以获取具有良好Cd2+去除性能的堆制物具有一定可行性。

       

      Abstract: The widespread existence of cadmium (Cd) contamination in soil environment has obtained extensive attention. There is growing interest to use organic wastes to remediate heavy metal pollution to achieve recycle of organic solid waste and the safe utilization of heavy metal contaminated soil. In this study, the vermireactors containing cow dung and shell powder were set up to obtain substrate residues for the removal of Cd2+ from aqueous solutions. The results demonstrated that earthworms showed considerably good survival rate with shell powder or modified shell powder addition. The earthworm treatment could reduce pH, C/N, lipid material and polysaccharide substance contents of substrate residues but increase its cation exchange capacity and the specific surface area, alcohol or carboxylic acids substance, aromatic substance, silicate, and soluble salts. Similarly, the addition of shell powder or modified shell powder could increase pH, cation exchange capacity and the specific surface area of substrate residues. The addition of shell powder added CaCO3, while the modified shell powder addition increased the content of CaCO3, CaO and Ca(OH)2 in substrate residues. The adsorption test showed that the removal efficiency of Cd2+ was the best for the substrate residues from cow dung and modified shell powder after earthworm treatment, and the adsorption rate was 59.9%. Therefore, it is feasible to set up the vermireactors containing cow dung and modified shell powder to produce substrate residues for the removal of Cd2+ in environment.

       

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