Comparative studies of Activated Carbon-attapulgite and Zeolite-attapulgite Composite Adsorbent on Congo Red Adsorption

摘要

This study investigated the adsorption of congo red by activated carbon-attapulgite composite adsorbent (ACA) and zeolite-attapulgite composite adsorbent (ZA) from aqueous solution. All of these two adsorbents have mesopores and macropores structure different from general activated carbon adsorbent with micropores distribution through analysis of mercury porosimeter. The research focused on the effects of adsorption capacity in four aspects: contact time, solution pH, temperature and initial dye concentration. The results indicated that ACA had higher adsorption rate in the first 30 min contact time and ZA had higher removal percentage because of the difference on the pore size and total pore area. There was little difference on removal percentage of ACA and ZA when pH changing from 1 to 13 and the adsorption rate exceeded 94% in all kinds of pH condition. The removal efficiency of congo red on ACA and ZA increased from 92% to 95% with increase of temperature from 293K to 323 K. The reduction rate of congo red decreased with an increase in the initial congo red concentration for ACA and ZA. These results suggest that all of the two adsorbents is a potential low-cost adsorbent for the dye removal from industrial wastewater.