椰壳活性炭对气态氯化汞吸附作用的对比研究

Characterization for Adsorption of Vapor-phase HgCl_2 on Coconut Shell Activated Carbon

以氯化汞为目标污染物,研究了椰壳活性炭对气态氯化汞的吸附性能,并结合活性炭微结构表征以及动力学模型拟合研究了其吸附机理。结果表明,椰壳活性炭对气态氯化汞的最大吸附量35.9 mg/g,且活性炭比表面积和总孔容对其吸附氯化汞有显著影响,比表面积大、总孔容大有利于提高饱和吸附量。载气流量不影响活性炭对氯化汞的饱和吸附量,但是影响其吸附时间,增大载气流量能够缩短吸附时间。温度对吸附量和吸附时间均有影响,升高温度能够提高吸附量且缩短吸附时间。通过对吸附过程的动力学模拟,发现活性炭对氯化汞的吸附均符合班厄姆动力学模型,相关系数均大于0.99,活性炭的吸附速率与吸附量随比表面积与总孔容的增大而增大。

With mercury chloride as pollution target, the adsorption properties of activated carbons for vapor-phase HgC12 were investigated. Combining with structural characterization and dynamic model fitting, the adsorption mechanism was discussed. The results indicated that the adsorption capacity of HgC12 on coco-nut shell activated carbon was 35.9 mg/g and obviously influenced by surface area and total volume. The gas flow didn＇ t influence the saturated adsorption quantity but the adsorption time is affected. The increase of the gas flow could shorten the adsorption time. The temperature affected the adsorption capacity and adsorption time, and raising temperature could increase the adsorption capacity and shorten the adsorption time. From the kinetic study,it was found that the HgC12 adsorption process of the activated carbon could be described by Bang, ham model with R2 〉 0.99, and the adsorption rate and capacity increased with the increase of surface area and total volume.