The effect of pretreatment on the adsorption efficiency of activated carbon

Abstract

Activated carbon (AC) is a very diverse adsorbent material with high porosity, high surface area, and excellent performance in vapor phase adsorption. The pretreatment provides a guaranteed way for the efficient adsorption performance of AC, which can remove the impurities and improve the porosity of AC. In this study, the difference between acid pretreatment and alkali pretreatment of coconut shell carbon was systematically investigated. The effect of heating with stirring pretreatment and ultrasonic pretreatment after acid treatment were also researched. The Brunauer-Emmett-Teller (BET) specific surface area, the N2 saturation adsorption, and the porosity of AC by acid-ultrasonic pretreatment can reach 1094.30 m2g−1, 352.51 cm3 (STP) g−1, and 0.5453 cm3g−1, respectively, which are higher than that of acid-heating with stirring pretreatment and alkali-heating with stirring pretreatment. Combined with the Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS) analysis data, AC by acid-ultrasonic pretreatment has a better microstructure and clearer aperture. Among the three methods of preprocessing, acid-ultrasonic pretreatment yields the most favorable results. This work provides a possible way for AC pretreatment.