酸碱二次改性活性炭对甲苯的吸附行为研究  

Study on the Adsorption Behavior of Toluene on Acid-base Secondary Modified Activated Carbon

作　　者：张佳[1] 魏倩 田晋平[1] 李秉正[1] 张珂 王梦娜 Zhang Jia;Wei Qian;Tian Jinping;Li Bingzheng;Zhang Ke;Wang Mengna(College of Environment and Resources,Taiyuan University of Science and Technology,Taiyuan Shanxi 030024)

机构地区：[1]太原科技大学环境与资源学院,山西太原030024

出　　处：《山西化工》2023年第5期3-7,22,共6页Shanxi Chemical Industry

摘　　要：本文利用HCl溶液和不同浓度NaOH溶液对椰壳活性炭进行改性,通过BET和SEM分析改性前后活性炭表面的结构变化,通过Boehm滴定法测定活性炭表面含氧官能团数量。结果表明,通过酸改性和二次碱改性都可使活性炭对甲苯和碘的吸附性能提高,当二次碱改性浓度为10 mol/L时,吸附性能最好,甲苯、碘吸附量为273.46 mg/g、1563.10 mg/g,与原活性炭吸附量相比,甲苯、碘吸附量分别增加51.02%、33.51%;改性后的活性炭2 nm左右的微孔增多;同时,酸性基团的增多抑制活性炭吸附甲苯的过程,碱性基团对活性炭的吸附影响不明显;甲苯在改性活性炭表面的等温吸附行为符合Langmuir等温吸附,为单分子层吸附;准一级动力学模型、准二级动力学模型均可以描述改性活性炭的吸附甲苯行为。Coconut shell-based activated carbon was modified by HCl and different-concentration NaOH solutions.The physical structure of activated carbon before and after modification were analyzed by SEM and BET methods,the number of functional groups on their activated carbon surface was determined by Boehm titration.The results show that both acid modification and secondary alkali modification can improve the adsorption capacity of toluene and iodine onto activated carbon.When the concentration of secondary alkali modification is 10 mol/L,the adsorption performance is best,because the adsorption capacity of toluene and iodine can reach 273.46 mg/g and 1563.10 mg/g.Compared with the original activated carbon,the adsorption capacity of toluene and iodine was greatly increased by 51.02%and 33.51%.The number of micropores around 2 nm has slightly increased,and surface area was obviously larger than before.It also shows the alkaline groups have no distinct effect on the adsorption of activated carbon.The adsorption behavior of toluene on activated carbon surface is consistent with Langmuir isothermal adsorption,which is monolayer adsorption.The adsorption curve can be described by quasi-first order kinetics and quasi-second order kinetics.

关 键 词：活性炭 酸改性 二次碱改性 吸附 甲苯 

分 类 号：TQ424.19[化学工程]