改性活性炭对亚甲基蓝的吸附性能及机理

以价廉易得的商业炭为原料,采用氢氧化钾为活化剂,制备出改性微孔活性炭。对其进行了表征分析,并将其用于吸附印染废水中的亚甲基蓝(MB)。结果表明,经活化改性后的活性炭孔径分布均匀,平均孔径为1.2 nm,比表面积高达2380 m^2/g(比商业炭提高了58.7%)。改性活性炭对MB的吸附过程符合Redlich-Peterson等温吸附模型,其吸附机理符合Langmuir模型的可能性较大,吸附动力学特征符合准2级动力学方程,吸附速率主要受颗粒内活性位点吸附步骤控制。改性活性炭在在室温下对MB的最大吸附量可达305.0 mg/g。吸附过程是自发进行的,温度的升高有利于吸附过程的进行与吸附量的提高。

Adsorption Performance and Mechanism of Methylene Blue by the Modified Activated Carbon

A new modified microporous activated carbon was successfully prepared,and the KOH was used as the activator,cheap and easily available commercial carbon as the raw material.The modified activated carbon was characterized and used for methylene blue(MB)adsorption in printing and dyeing wastewater.The results showed that the pore size distribution of the activated carbon was uniform with the average pore size of 1.2 nm,the specific surface area of the modified carbon was 2380 m^2/g,which was 58.7%higher than that of commercial carbon.The adsorption process of MB on the modified activated carbon was best correlated to the Redlich-Peterson isothermal adsorption model.The adsorption mechanism conformed to the Langmuir model.The kinetic data exhibited better fit to the quasi-second-order kinetic model.And the adsorption of the MB on the intraparticle surface active sites was the main rate control step.The maximum adsorption capacity of MB was of 305.0 mg/g at room temperature.The adsorption process was spontaneous,and the temperature increase was beneficial for adsorption process and adsorption capacity.