微波加热制备椰壳活性炭吸附含Pb^(2+)废水特性研究

Characteristics of Adsorption of Pb^(2+) from Effluents onto Activated Carbon Prepared from Coconut Shell by Microwave Heating

采用微波加热水蒸气活化法制备了椰壳活性炭(MAC),用于吸附水溶液中的Pb2+,并对吸附热力学进行了探讨。吸附热力学研究中考察了温度对吸附的影响。应用Van′t Hoff方程对热力学参数(标准吉布斯自由能ΔG、标准焓ΔH、标准熵ΔS)进行了计算。热力学研究表明:Pb2+吸附于MAC上是一个自发进行的放热过程。采用Langmuir和Freundlich吸附等温式对不同温度下获得的吸附平衡数据进行了分析,结果显示Langmuir模型对实验数据能更好的进行拟合。

Adsorption of Pb^2＋ from aqueous solution onto activated carbon prepared from coconut shell by microwave heating （MAC） was investigated in a batch system. The effects of temperature on adsorption thermodynamics were studied. Thermodynamic parameters such as standard Gibbs free energy （△G ） , standard enthalpy （△H ） , and standard entropy （△S ） were evaluated by applying the Van＇t Hoff equation. The thermodynamics of Pb2^＋ adsorption onto activated carbon indicates that it is of spontaneous and exothermic nature. Langmuir and Freundlich isotherms were used to analyze the equilibrium data at different temperatures and the equilibrium data were found to be well represented by the Langmuir isotherm equation.