市政污泥热解炭对铅的吸附性能及影响因素研究

Research on the Adsorption Performance and Influencing Factors of Lead by Municipal Sludge Pyrolytic Carbon

采用热解的方法用市政污泥制备污泥热解炭,用吸附实验方法探讨了市政污泥热解炭对Pb^(2+)的吸附性质及影响因素。结果可得:当热解温度为800℃时,市政污泥热解所得的热解炭对Pb^(2+)有较好的吸附性能。在实验温度为25℃、pH为6.06、投加量1 g/L的条件下,MSB800对Pb^(2+)的最大吸附容量为140.16 mg/g,吸附平衡时间为30 min,并且对Pb^(2+)的吸附动力学和等温吸附线分别可以用拟二级动力学和Langmuir等温线描述。通过SEM、FTIR和XRD等手段对污泥热解炭吸附前后的表征分析可得,热解炭对Pb^(2+)的吸附机制可能为:矿物沉淀和阳离子-π作用。

The pyrolysis method was used to prepare sludge pyrolysis carbon from municipal sludge,and the adsorption properties and influencing factors of municipal sludge pyrolysis carbon for Pb^(2+)were discussed using adsorption experimental methods.The results could be obtained:when the pyrolysis temperature was 800℃,the pyrolytic carbon obtained from the pyrolysis of municipal sludge had better adsorption performance for Pb^(2+).Under the conditions of the experimental temperature of 25℃,pH of 6.06,and dosage of 1 g/L,the adsorption capacity of MSB800 for Pb^(2+)was 140.16 mg/g,the adsorption equilibrium time was 30 min,and the adsorption kinetics and isothermal adsorption line of Pb^(2+)They could be described by pseudo-second-order kinetics and Langmuir isotherm respectively.Characterization analysis of sludge pyrolytic carbon before and after adsorption by means of SEM,FTIR and XRD revealed that the adsorption mechanism of Pb^(2+)by pyrolytic carbon may be:mineral precipitation,functional group complexation and ion exchange.