Xie Hongmei, Liu Na, Wang Haoyu, Chen Shuang, Zeng Jia, Zhou Guilin
Chongqing Key Laboratory of Catalysis and Environmental New Materials, Department of Chemical Engineering, Chongqing Technology and Business University, Chongqing, 400067, China.
Engineering Research Center for Waste Oil Recovery Technology and Equipment, Ministry of Education, Chongqing Technology and Business University, Chongqing, 400067, China.
Environ Sci Pollut Res Int. 2023 Oct;30(47):104194-104208. doi: 10.1007/s11356-023-29806-w. Epub 2023 Sep 12.
Waste Zanthoxylum bungeanum branches were used to prepare activated carbon adsorbents with high mesopore ratio by HPO staged activation method with adding KNO additive. The prepared activated carbon adsorbents were characterized by SEM, BET, FT-IR, and XRD. The adsorption properties of the prepared activated carbon adsorbents were evaluated by the toluene adsorption/desorption in air. The quasi-first-order, quasi-second-order, and Bangham models were used to fit the obtained toluene adsorption results. The oxidative etching of KNO additive improved the pore-forming ability of the HPO activator to enhance the activation pore-forming effects of the selected biomass raw material. The secondary pore-forming effects of K atoms promoted the effective expansion of the pore diameter in the activated carbon preparation process to prepare activated carbon adsorbents with high mesopore proportion. The specific surface area and mesopore proportion of the activated carbon adsorbents prepared by adding KNO additive exceeded 1100 m/g and 71.00%, respectively, and the toluene adsorption capacity exceeded 370.00 mg/g. The rich mesopore structures can effectively reduce the toluene mass transfer resistance, which can promote the corresponding activated carbon adsorbent to be regenerated by low-temperature (40 °C) thermal desorption. The toluene adsorption on the prepared activated carbon adsorbents includes surface adsorption and diffusion in pore structures, and the toluene adsorption mechanism is more consistent with the Bangham kinetic model.
采用添加KNO添加剂的HPO分段活化法，以废弃花椒树枝为原料制备了中孔率高的活性炭吸附剂。采用扫描电子显微镜（SEM）、比表面积分析仪（BET）、傅里叶变换红外光谱仪（FT-IR）和X射线衍射仪（XRD）对所制备的活性炭吸附剂进行了表征。通过甲苯在空气中的吸附/脱附实验，对所制备的活性炭吸附剂的吸附性能进行了评价。采用准一级、准二级和Bangham模型对获得的甲苯吸附结果进行拟合。KNO添加剂的氧化刻蚀作用提高了HPO活化剂的造孔能力，增强了所选生物质原料的活化造孔效果。K原子的二次造孔作用促进了活性炭制备过程中孔径的有效扩展，从而制备出中孔比例高的活性炭吸附剂。添加KNO添加剂制备的活性炭吸附剂的比表面积和中孔比例分别超过1100 m²/g和71.00%，甲苯吸附量超过370.00 mg/g。丰富的中孔结构能够有效降低甲苯传质阻力，促使相应的活性炭吸附剂通过低温（40℃）热脱附实现再生。所制备的活性炭吸附剂对甲苯的吸附包括表面吸附和在孔结构中的扩散，甲苯吸附机理更符合Bangham动力学模型。
