政污泥生物碳对重金属的吸附特性研究.docVIP

市政污泥生物碳对重金属的吸附特性研究 李江山，薛强*，王平，刘磊中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室，武汉 430071 湖北省固体废弃物安全处置与生态高值化利用工程技术研究中心，武汉 430071 摘要：采用市政污泥在300℃缺氧条件下制得污泥生物碳，研究了污泥生物碳添加量、溶液pH及吸附反应时间对溶液中Pb、Cu、Zn吸附效果的影响，并分析和讨论了各因素影响机制及污泥生物碳对重金属的吸附机理。研究结果表明：污泥生物碳对溶液中重金属的去除率大小与重金属水合离子半径大小成反比例关系，随着污泥生物碳添加量的增加，溶液中重金属的去除率不断增加，但单位吸附量总体上呈下降趋势。重金属吸附量随溶液pH的增加而增大，当溶液初始pH值等于6左右时，污泥生物碳对溶液中重金属的吸附量最大。伪二级动力学模型可有效描述溶液中重金属离子在生物碳上的吸附过程，重金属在污泥生物碳表面的吸附主要受化学反应控制，Pb、Cu和Zn的平衡吸附量分别为39.747、6.849和10.004mg/g，平衡时间大小顺序为: Pb＞Zn＞Cu。 关键词：污泥；生物碳；重金属；吸附 Adsorption of municipal sludge biochar for soluble heavy metals LI Jiang-shan1,2, XUE Qiang1,2*, WANG Ping1,2, LIU Lei1,2 1. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China 2. Hubei Provincial Engineering Reseach Center of Safety Treatment and Ecological High-value of MSW, Wuhan 430071, China Abstract: Sludge-derived biochars were prepared at 300℃ and hypoxia. The effects of addition amount, pH and contact time on adsorption of Pb2+、Cu、Zn in solution by sludge-derived biochars were investigated firstly, then the influence and adsorption mechanisms were discussed. The results showed that removal rate of heavy metals in solution adsorbed by sludge derived biochar was inversely proportional to the hydrated ionic radius of heavy metals, with the increase of sludge-derived biochars added, the removal rate of heavy metals increased, but adsorption amount per unit mass showed a downward trend. Adsorption amount of heavy metals was increased with the increase of pH in solution, and the maximum value appeared when pH equaled to about 6, the adsorption capacity of Pb2+, Cu2+ and Zn2+ was 42.941、25.769 and 12.484mg/g respectively. Pseudo second-order model can effectively describe the adsorption process of heavy metal ions on sludge-derived biochar, which was mainly controlled by the chemical reaction. The equilibrium adsorption capacity of Pb2+, Cu2+ and Zn2+ was 39.747, 6.849 and 10.004mg/g res