Adsorption of dibenzothiophene sulfone from fuel using chitosan-coated bentonite (CCB) as biosorbent

Removal of dibenzothiophene sulfone (DBTS) from fuel onto chitosan-coated bentonite (CCB) was investigated using a fixed-bed column system. The experiments were carried out as a function of flow rate, particle size, and initial feed of DBTS concentration. The bed adsorption capacities were found to increase with the decreasing flow rate and particle size. Maximum bed adsorption capacities for the various flow rates were found to be 4.30, 3.09, and 2.44mg DBTS/g CCB at 1, 5, and 10mL/min, respectively. When the initial DBTS concentration was increased from 500 to 1,000mg/L, the corresponding adsorption bed capacity appears to increase from 4.31 to 5.55mg/g. Spectra studies showed possible involvement of hydroxyl groups in the biosorption. The Thomas model was used to predict the breakthrough curves under varying experimental conditions. Results indicate a good agreement between the experimental data and predicted breakthrough curves generated by the Thomas model.