中文摘要：

采用质量分数为3％的Na2S溶液对活性炭浸渍，在600℃以N2作为保护气对其进行高温处理，研究Na2S改性活性炭（SAC）吸附Pb（Ⅱ）的动力学和热力学机理，并对吸附Pb（Ⅱ）前后的改性活性炭进行了表征和分析。结果表明，与改性前活性炭相比，SAC的比表面积和总孔容减小，s元素含量显著提高。SAC对Pb（Ⅱ）的吸附效果显著提高，在Pb（Ⅱ）初始浓度为300mg／L时，SAC对Pb（Ⅱ）最大吸附量为122．56mg／g，并且在吸附过程的前80min内可达到总吸附量的95％以上。SAC对Pb（Ⅱ）的吸附过程可用Langmuir模型描述，动力学特性符合拟二级动力学模型。SAC对Pb（Ⅱ）的吸附的热力学参数△G在-80-20kJ／mol之间，△H〈0，△S〉0，表明吸附是自发进行的物理吸附与化学吸附共同作用的放热过程。对吸附前后改性活性炭的傅里叶变换红外谱图分析表明，经过NaES改性后，活性炭表面引入了砜基，并且砜基强化了改性活性炭对Pb（Ⅱ）的吸附性能。

英文摘要：

Na2S-modified activated carbon （SAC） was prepared by impregnation of 3% （wt%） Na2S solution and followed by heat treatment at 600℃ under N2 atmosphere. The thermodynamics behavior and kinetics mechanism of Pb（Ⅱ） adsorbed on SAC were studied. The surface functional groups of SAC before and after adsorption of Pb（Ⅱ） were analyzed by FT-IR, elemental analysis and determination of characteristic pore structural parameters. The results showed that the sulfur content in SAC significantly increased while both BET surface area and total pore volume of SAC decreased than that of AC. Compared with AC, SAC demonstrated better adsorption performance with maximum adsorption capacity of 122.56mg/g for Pb（Ⅱ） at the initial concentration of 300mg/L. More than 95% Pb（Ⅱ）in the aqueous solution was adsorbed in 80 minutes. Besides, isothermal adsorption and kinetic process could be described by Langmuir model and Pseudo-second-order rate equation, respectively. The values of thermodynamic parameters for Adsorption of Pb（Ⅱ） on SAC were calculated and the results showed that free energy change （△G） was between -80kJ/tool and -20kJ/mol, enthalpy change （△H） was negative, and entropy change （△S） was positive, which indicated that the adsorption of Pb（Ⅱ） on SAC was a spontaneously endothermic process with physisorption and chemisorption. In addition, FT-IR spectra of SAC before and after Pb（Ⅱ） adsorption revealed that sulfur-contained functional groups on the surface of SAC contributed to the chemisorption of Pb（Ⅱ）.