湿氧化改性多孔炭对低浓度苯和丁酮蒸汽的吸附

空气中挥发性有机化合物 (VOC)严重危害人体的身体健康 ,因而研究 VOC的去除具有重要意义。该文研究了椰壳活性炭 (AC)和粘胶基活性炭纤维 (ACF)湿氧化处理后对低浓度 VOC苯和丁酮的吸附。 AC和 ACF分别用质量分数为 30 %和 5 0 %的 H2 O2 、浓 HNO3进行湿氧化处理。采用 X射线光电子能谱 (XPS)和氮气容量法研究了 ACF,采用扫描电镜 (SEM)研究了 AC处理前后性质的变化。并利用热重分析仪 (TGA)研究了对挥发性有机化合物丁酮和苯的吸附。实验结果表明 :ACF经 H2 O2 处理后具有活化作用 ,比表面积和微孔容积都增加了 ,特别是用质量分数为 30 %的 H2 O2 处理后更有利于低浓度苯和丁酮的吸附 ;AC经湿氧化处理后 ,扫描电镜下呈现不同的微观形貌特征 ,质量分数为 30 %的 H2 O2 处理后 ,增强了对苯的吸附 ,减弱了对丁酮的吸附。

Adsorption of benzene and methyl-ethyl-ketone vapors at low concentration by wet oxidized porous carbons

Volatile organic compounds (VOC) must be removed because airborne VOC endanger human health. The present work studied the adsorption of low concentration VOC such as benzene and methy ethyl ketone (MEK) onto wet oxidized coconut shell activated carbon (AC) and viscose rayon based activated carbon fiber (ACF). The AC and ACF were both treated with 30% and 50% H 2O 2 in addition to concentrated HNO 3. The characteristics changes of ACF and AC before and after wet oxidation were measured by X ray photoelectron spectroscopy (XPS) and the nitrogen volumetric measurement method, and by scanning electron microscopy (SEM), respectively. The adsorption of polar MEK and weakly polar benzene was experimentally studied by means of thermogravimetric analysis (TGA). The results showed that the H 2O 2 treatment exhibited activation effect. The BET specific surface area and micropore volume of ACF were increased by oxidation with H 2O 2. Especially, treatment with 30% H 2O 2 improved the adsorption of benzene and MEK at low concentrations. The AC before and after oxidation also exhibited different micro morphology. Oxidation of AC by 30% H 2O 2 enhanced the adsorption of benzene and weakened the adsorption of MEK.