磷酸活化脱墨渣制备中孔活性炭研究

Preparation and Characterization of Mesoporous Activated Carbon Prepared from Deinking Residue Using Phosphoric Acid as Activator

关键词:  磷酸  脱墨渣  中孔活性炭

Key Words:phosphoric acid  deinking residue  mesoporous activated carbon

摘要:以废纸脱墨渣(污泥)为原料,通过磷酸活化法制备中孔活性炭,以碘吸附值和亚甲基蓝吸附值为考察指标,研究了活化时间、活化温度、浸渍比及磷酸浓度等对活性炭吸附性能的影响。得到的最佳制备条件为：活化时间90 min,活化温度450 ℃,浸渍比1∶3.5,磷酸浓度70%。此条件下脱墨渣活性炭得率为54.57%,得到的脱墨渣活性炭碘吸附值为421.98 mg/g,亚甲基蓝吸附值为10.97 mL/g,比表面积、总孔容和中孔率分别达715.576 m2/g、0.353 mL/g和97.45%。磷酸活化法制备的脱墨渣活性炭比表面积较大,中孔发达。红外光谱、扫描电镜及X射线衍射表征表明，脱墨渣活性炭表面含有大量羟基等多种官能团；脱墨渣活性炭的晶化程度较大,微晶不规则,孔隙结构稳固。以脱墨渣为原料采用磷酸活化技术可成功制备出中孔活性炭。

Abstract:The mesoporous activated carbon was prepared using deinking residue as raw materials and phosphoric acid as activating agent. The optimum preparation conditions were studied and the iodine adsorption value and methylene blue adsorption value were taken as evaluation index. The optimal conditions were as the follows: the ratio of material to liquid and the concentration of phosphoric acid were 1∶3.5 and 70%, respectively, the activating time was 90 min at 450℃. Under these conditions, the iodine adsorption capacity and methylene blue adsorption value of activated carbon reached to 421.98 mg/g, 10.97 mL/g, respectively. The N2 adsorption desorption isotherms results indicated that the specific surface area, total pore volume and mesoporosity rate of the activated carbon were 715.576 m2/g, 0.353 mL/g and 97.45%, respectively. FT-IR analysis of chemical properties of activated carbon showed that there were varieties of functional groups, such as hydroxyl on the surface, XRD and scanning electron microscope analysis indicated that activated carbon had high crystallization, the microcrystalline was irregular and the pore structure was stable. Phosphoric acid activation was proven an effective technology to prepare mesoporous activated carbon using the deinking residue．