竹皮活性炭高效吸附工业废水中高质量浓度铬离子的热力学和动力学研究  

Study on Thermodynamics and Kinetics of High Efficiency Adsorption of Chromium Ions in Industrial Wastewater by Bamboo Bark Activated Carbon

作　　者：张艳娟 张锟 ZHANG Yanjuan;ZHANG Kun(Hunan Petrochemical Vocational Technology College,Yueyang Hunan 414011,China)

机构地区：[1]湖南石油化工职业技术学院,湖南岳阳414011

出　　处：《当代化工》2024年第10期2359-2364,共6页Contemporary Chemical Industry

基　　金：湖南省教育厅科学研究项目(项目编号:22C1068)。

摘　　要：采用炭化-水蒸气活化两段法制备的竹皮活性炭吸附铬离子,研究吸附过程的热力学及动力学。研究发现,Langmuir模型最能描述竹皮活性炭对溶液中铬离子的吸附行为,说明竹皮活性炭表面性质均一,官能团分布均匀,铬离子在活性炭表面为单分子层吸附。在30℃时的最大单层吸附量为193 mg·g^(-1),与其他文献报道的生物质活性炭相比具有明显优势。热力学研究结果表明,该吸附是一个自发的过程并且吸收热量,升高温度有利于铬离子的吸附,且吸附剂对活性炭有较强的吸附亲和力。吸附动力学实验结果表明,该吸附过程更符合准二级动力学方程,主要为化学吸附。颗粒内扩散不是吸附过程存在的唯一速率控制步骤,还有其他机制参与。The thermodynamics and kinetics of adsorption of chromium ions on bamboo bark activated carbon prepared by carbonization and steam activation were studied.It was found that Langmuir model could best describe the adsorption behavior of chromium ions in solution by bamboo bark activated carbon,indicating that the surface properties of bamboo bark activated carbon were uniform,the distribution of functional groups was uniform,and chromium ions were adsorbed in single molecular layer on the surface of activated carbon.The maximum single-layer adsorption capacity at 30℃was 193 mg·g^(-1),which had obvious advantages compared with the biomass activated carbon reported in other literatures.Thermodynamic study results showed that the adsorption was a spontaneous process and absorbed heat.Increasing the temperature was conducive to the adsorption of chromium ions,and the adsorbent had a strong adsorption affinity for activated carbon.The adsorption kinetics experiment results showed that the adsorption process was more consistent with the pseudo-second-order kinetic equation,which was mainly chemical adsorption.Intraparticle diffusion was not the only rate-controlling step that existed in the adsorption process,and there were other mechanisms involved.

关 键 词：竹皮活性炭 铬离子 热力学 动力学 

分 类 号：TQ424.1[化学工程]