活性炭对水中微量酰胺咪嗪吸附规律  

Adsorption rules of activated carbons for trace carbamazepine in water

作　　者：吕婧[1] 张立秋[1] 封莉[1] 

机构地区：[1]北京林业大学北京水体污染源控制技术重点实验室,北京100083

出　　处：《环境工程学报》2012年第10期3529-3536,共8页Chinese Journal of Environmental Engineering

基　　金：教育部博士点新教师基金(20090014120018);教育部新世纪优秀人才项目(NCEF-08-0732)

摘　　要：选择3种商品活性炭(煤质炭MAC、杏壳炭XAC、椰壳炭YAC),从其对水中微量药物酰胺咪嗪(carbamaz-epine,CBZ)的吸附平衡、吸附等温式、吸附动力学和热力学等方面详细考察了不同种类活性炭对CBZ的吸附去除规律。实验结果表明,3种活性炭与CBZ接触反应10 h后均达到吸附平衡,对CBZ的平衡吸附量在8.3 mg/g左右;比较了Lang-muir和Freundlich两种吸附等温式,发现Langmuir方程更适合描述3种活性炭对CBZ的吸附过程;计算表明3种活性炭的吸附过程均符合拟二级动力学方程,Weber-Morris方程的模拟结果则说明膜扩散和内扩散共同限制了3种活性炭对CBZ的吸附速率;3种活性炭的Ea值分别为29.87 kJ/mol(MAC)、36.02 kJ/mol(XAC)和38.86 kJ/mol(YAC),表明3种活性炭吸附CBZ时同时发生了物理吸附和化学吸附作用,且以化学吸附为主;20～40℃时3种活性炭的△G均为负值,说明3种活性炭对CBZ的吸附反应可以自发进行;MAC、XAC、YAC的△H值分别为-3.10、-3.05和-3.02 kJ/mol,负值表明吸附过程放热,上述△H值较小则说明温度对CBZ的吸附影响不大;3种活性炭吸附CBZ过程的△S值为0.94 J/(mol.K)(MAC)、2.24 J/(mol.K)(XAC)和2.97 J/(mol.K)(YAC),说明吸附过程熵值增加,在外界条件不改变的情况下该吸附过程不可逆,同时可以看出在3种活性炭中,CBZ分子更倾向于吸附在YAC上。The removal of trace carbamazepine（CBZ） in water by absorption of three kinds of commercial activated carbon（coal carbon MAC、apricot carbon XAC and coconut carbon YAC） was studied using the adsorption equilibrium,adsorption isotherm,adsorption kinetics and thermodynamics.The results showed that the adsorption equilibrium of each ACs was obtained after about 10 hours.Similar adsorption quantities of CBZ were achieved about 8.3 mg/g.Langmuir adsorption isotherm equation was more suitable to describe the adsorption process compared with Freundlich equation.It was shown that the pseudo second-order kinetic equation could describe the adsorption kinetics for CBZ onto the three ACs,while the boundary layer diffusion and intra particle diffusion are rate limiting.The activation energy（Ea） values of three ACs were 29.87 kJ/mol（MAC）,36.02 kJ/mol（XAC）,38.86 kJ/mol（YAC）,indicating the common effect of physical and chemical adsorption and do minance of the latter.Furthermore,the negative values of △G at 20～40℃ suggested that the adsorptions were spontaneous;the △H values of MAC,XAC and YAC were-3.10,-3.05,-3.02 kJ/mol,respectively,which indicated exothermic character of the adsorption processes and weak influence of temperature;the values of △S were 0.94 J/（mol·K）（MAC）,2.24 J/（mol·K）（XAC）,2.97 J/（mol·K）（YAC）,meaning the process was irreversible under the given environmental conditions.

关 键 词：活性炭 酰胺咪嗪 Langmuir吸附等温式 动力学 热力学 

分 类 号：TU991.25[建筑科学—市政工程]