摘要:The effect of iron doping on the physico-chemical properties of activated carbon (AC) and effects of adsorption conditions (contact time, initial phenol concentration, and Fe doping mass fraction) on adsorption behavior of phenol removal from aqueous solutions on AC and irondoped AC were investigated. The adsorbents were characterized using elemental analyses, N2 adsorption, X-ray diffraction and Boehm titration. The results show Fe2O3 is mainly dispersed on the AC surface. Moreover, the pore properties of AC change insignificantly after the doping, but the acidic oxygenated groups of AC surface increases greatly. Large amount of phenol was removed by the adsorbents before 120 min and the equilibrium was reached in 240 min. Removal percentage increased with increasing contact time before 240 min. The efficiency of adsorbents obviously decreased with increasing initial phenol concentration (large than 250 mg/L). The order for the removal percentage of phenol at the same initial concentration onto the three adsorbents follows AC > Fe1/AC > Fe5/AC, which is ascribed to the increase in the oxygenated groups on AC surface from Fe coping. The uptake of phenol onto the adsorbents increases with increasing the equilibrium concentration. Fe doping insignificantly influences the uptake of Fe/AC for low-concentration phenol, but the uptake of Fe/AC is obviously less than that AC when high-concentration phenol in water was adsorbed. The order for the uptakes of phenol at the same equilibrium concentration on the three adsorbents follows: AC > Fe1/AC > Fe5/AC Freundlich isotherm better describes the adsorption process.
关键词:adsorption; phenol; iron doping; surface groups; adsorption model