δ-MnO_2吸附染料亚甲基蓝的动力学和机理

Kinetic analysis and mechanisms for adsorption of methylene blue from aqueous solution onto δ-MnO_2

为改善印染废水的深度处理效果,通过静态吸附试验研究δ-MnO2吸附水中阳离子染料亚甲基蓝的动力学和机理.研究混合强度、初始染料质量浓度、MnO2投量、pH和温度对吸附速率的影响,得出表观动力学方程,并考察吸附机理.结果表明:吸附过程符合表观2级动力学方程,物料传递和微孔扩散是限速步骤.试验条件下对亚甲基蓝的吸附容量可达0.244 mg/mg.较高的吸附容量和较快的吸附速率使δ-MnO2有望应用于印染废水深度处理.

In order to improve the effect of advanced treatment of dye wastewater, the kinetics and mechanisms of adsorption of a cationic dye, methylene blue, from aqueous solutions by δ-MnO2 was investigated using batch rate experiments. Researches were performed at various strength of mixing, initial dye concentrations, solid loads and pH values. Apparent kinetic model and mechanisms of dye removal were also investigated. Results indicate that the adsorption process obeyed the pseudo -second -order kinetic model. The mass transfer and intraparticle pore diffusion are rate - controlling steps. The adsorption capacity is 0. 244 mg/mg under the condition. The relatively high capacity and quick velocity of sorption make MnO2 a potential sorbent for advanced treatment of dye wastewater.