Adsorptive desulfurization of dibenzothiophene by sewage sludge-derived activated carbon

Abstract

The removal of dibenzothiophene (DBT) from n-octane was performed using an adsorption process with sewage sludge-derived activated carbons (S-ACs) at ambient conditions. The effect of varying the type of activating agent (ZnCl2, HNO3 and KOH), activating agent:char weight ratio (0.5–6w/w), carbonization temperature (400–800°C) and time (0.5–2h) on the physicochemical properties and the adsorption capacity of the S-ACs were investigated. All the studied parameters were found to play an important role on the physicochemical properties as well as the surface chemistry of the S-ACs. The DBT adsorption capacity increased as the increase of oxygen-containing functional group, especially the carbonyl group. The S-AC prepared by KOH-activation exhibited the highest adsorption capacity with up to 14.12mg/g or around 70.6% DBT removal, which were greater than that of a commercial activated carbon (C-AC) of around 1.28- and 1.22-fold, respectively. The adsorption of DBT via S-AC followed the Langmuir isotherm.