高中空生物质活性碳纤维制备及其对亚甲基蓝的吸附性能

为提高活性碳纤维对有色废水的吸附效率,以牛角瓜纤维为前驱体,采用磷酸活化、高温炭化工艺制备了具有高中空结构的活性碳纤维。采用扫描电镜/能谱仪、红外光谱仪等表征其微观形貌及化学结构,分析了所制备活性碳纤维对水溶液中亚甲基蓝的吸附性能与吸附机制。结果表明:牛角瓜活性碳纤维的平均中空度大于92%,具有粗糙表面和发达介孔结构,比表面积和平均孔径分别为1 244.812 m ²/g和3.744 nm;活性碳纤维表面富含O、P元素,构成了活性表面;亚甲基蓝溶液(100 mg/L)的饱和吸附量为198.840 mg/g,该吸附满足准二级动力学方程,同时符合Freundlich模型,以多层吸附为主。

Preparation of highly hollow biomass-based activated carbon fiber and its adsorption property to methylene blue

In order to improve the adsorption efficiency of activated carbon fiber to colored wastewater,the activated carbon fibers with highly hollow structures were prepared,using the calotropis gigantea fiber as the precursor,by phosphoric acid activation and high temperature carbonization.The morphology,chemistry and pore structures of the calotropis gigantean activated carbon fiber were characterized systematically by scanning electron microscopy-energy dispersive spectrometer,Fourier transform infrared spectrocopy methods.Meanwhile,the adsorption properties and mechanism of carbon fibers to methylene blue were analyzed.The results show that the average hollow degree of calotropis gigantea activated carbon fiber is more than 92%,and the fiber also exhibits a rough surface and develops mesoporous structures with the specific surface area and average pore diameter of 1244.812 m2/g and 3.744 nm,respectively.Moreover,the surface of carbon fiber is rich in elements O and P,which constitute the active surface of carbon fiber.The saturated adsorption capacity of the carbon fiber to methylene blue aqueous solution with initial mass concentration of 100 mg/L can reach 198.840 mg/g.The adsorption process to methylene blue follows the pseudo-second-order kinetic equation.The adsorption to methylene blue conforms to the Freundlich model,which is mainly multilayer adsorption.