Adsorption of toluene by fixed sludge-based activated carbon bed
污泥活性炭固定床吸附甲苯

Sludge-based activated carbon was produced by ZnCl2 chemical activation of dewatered sludge, and was used as adsorbent for toluene in fixed bed. At the same time, the effects of bed depth, initial concentration and gas linear velocity on removal of toluene were studied, and mass transfer model for this process was established to calculate mass transfer zone and total mass transfer coefficient. Results show that with bed depth changing from 3 cm to 5 cm, mass transfer zone has no significant change, while the total mass transfer coefficient increases by 66.66%; mass transfer zone increases by 17.19% and total mass transfer coefficient reduces by 22.05%with the toluene concentration increasing by 3.36 times. In the operation of the gas linear velocity range, with the gas linear velocity double than that of the original, total mass transfer coefficient increases by 65.27%, which indicates that this process belongs to external diffusion control.