Papers by Author: Wei Shen

Abstract: The aim of this study was the assessment of reduction of chemical oxygen demand (COD) from micro-polluted water using activated carbon-attapulgite composite adsorbent prepared using activated carbon and natural attapulgite through compounding, granulation and calcination. The complete study was done in batch mode to investigate the effect of operating parameters. Adsorption of COD was found to be dependent on contact time, pH, temperature and initial COD concentration. Adsorption equilibrium attained within 80 minutes time. The optimum pH range for adsorption of organics was found to be 8. The sorption of organics decreased with rise of temperature because adsorption process was exothermic. The studied adsorption data fitted well to Langmuir adsorption model with the correlation coefficient 0.9947. The activated carbon-attapulgite composite adsorbent in this study shows very good promise for practical applicability on removal of COD from micro-polluted water.

Abstract: 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 to323K. 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.