Abstract

Commercial activated carbon of coconut shell has been oxidized with nitric acid, and their oxygen surface complexes have been characterized by classical titration following Boehm’s method and by FTIR. The surface areas of both the original and oxidized activated carbon were obtained 814 m² g⁻¹ and 626 m² g⁻¹ with an average micropore volume of 1.67 and 1.79 cm³ g⁻¹, respectively. A comparative study on the toluene adsorption revealed that the oxidized activated carbon showed better toluene adsorption. The adsorption capacity of toluene was enhanced dramatically by oxidation of the activated carbon. The highest adsorption and breakthrough times of the functionalized (FAC) and nonfunctionalized activated carbon (NFAC) were 110.39 mg g⁻¹, 67.18 min, and 65.38 mg g⁻¹, 32.29 min, respectively. An adsorbent mass of 60 mg, the flow rate of 90 mL min⁻¹, toluene concentration of 500 ppm, the humidity of 30%, and temperature of 26 °C was found to be the optimum conditions for the maximum adsorption capacity of toluene of 112.11 mg g⁻¹ by the FAC in a dynamic adsorption system. The FAC obtains an adsorption capacity of 71.28 mg g⁻¹ in the third cycle, which is about 65% of the preliminary values. Due to the high adsorption capacity of the FAC in the adsorption of toluene and proper reusability and stability, it can be used as a suitable and economical adsorbent.

摘要

椰壳活性炭已用硝酸氧化，其氧表面复合物已通过 Boehm 方法和 FTIR 的经典滴定进行表征。原始活性炭和氧化活性炭的表面积分别为 814 m ² g ^-1和 626 m ² g ^-1，平均微孔体积分别为 1.67 和 1.79 cm ³ g ^-1， 分别。对甲苯吸附的比较研究表明，氧化活性炭表现出更好的甲苯吸附。通过活性炭的氧化，甲苯的吸附能力显着增强。功能化（FAC）和非功能化活性炭（NFAC）的最高吸附和穿透时间分别为110.39 mg g ^-1、67.18 min 和65.38 mg g ^-1、32.29 min。发现吸附剂质量为 60 mg、流速为 90 mL min ^-1、甲苯浓度为 500 ppm、湿度为 30%、温度为 26 °C 是甲苯最大吸附量的最佳条件。 112.11 毫克克^-1由动态吸附系统中的 FAC。FAC在第三个循环中获得 71.28 mg g ^-1的吸附容量，约为初始值的 65%。由于FAC在甲苯吸附中具有较高的吸附能力和适当的重复使用性和稳定性，可作为一种合适且经济的吸附剂。