超细粉煤灰基吸附剂吸附次甲基蓝动力学研究

Kinetics of adsorption of methylene blue from aqueous solution by ultra-fine fly ash based adsorbents

将粉煤灰粉碎、化学处理、复合成型处理后制得一种超细粉煤灰基吸附剂.研究该吸附剂吸附水溶液中次甲基蓝的吸附动力学和吸附机理.通过分光光度法测定在不同吸附时间溶液中的剩余次甲基蓝吸光度值,求出溶液中剩余的次甲级蓝的浓度以及吸附在吸附剂上的次甲级蓝吸附量;根据不同时间的吸附量拟合吸附动力学方程.结果表明,该吸附剂对次甲基蓝的吸附符合二级动力学速率方程,求得平衡吸附量为0.8274mg/g;求得在两个不同温度下的吸附速率常数分别为:(298K)0.798g/(mg.min)、(313K)0.963g/(mg.min),吸附活化能()为9.684kJ/mol.本实验探索了以粉煤灰为原料制备的超细吸附剂对次甲基蓝废水治理新途径,为粉煤灰的综合利用提供理论依据.

Ultra fine fly ash based adsorbent was provided through fly ash which is milled, and chemicaly treated and mold- ed. Adsorption capacity and mechanism of methylene blue on the adsorbent have been studied. The concentration of methylene blue in the remainder solution and the adsorption capacity of the adsorbent at different times were obtained by spectrophotometry. The kinetic equation was fitted according to the adsorption in different times. The results showed that the adsorption can be expressed by the pseudo second order model. The adsorption balance capacity was obtained as 0. 827 4 mg/g. The adsorption rate constant qe was measured as 0. 798 g/（mg ·min） at 298K and as 0. 963 g/（mg ·min） at 313 K, respectively. According to the two rate constants at different temperatures, adsorption activation energy （E,） was calculated as 9. 684 kJ/（mol）. This study explored new treatment channels for fly ash comprehensive utilization.