Abstract:
This work was carried out to investigate the effect of parameters on the preparation of activated carbon from sewage sludge for adsorption of sulfur compound in diesel fuel. The utilized model fuel was dibenzothiophene at concentration of 100 ppm in n-octane. Three types of activating agent were utilized including KOH, ZnCl2 and HNO3 at different ratios of activating agent to char (0.5, 1, 2, 4 and 6 (w/w)). The results showed that typs of activating agent, ratios of activating agent to char and step of heat treatment had important roles on the adsorption capacity of dibenzothiophene. The activated carbon activated by KOH as two-step heat treatment at the ratio between KOH and char of 6:1 at temperature of 600 oC for 1 hr, flow rate of N2 of 50 ml/min and heating rate of 10 oC/min provided the maximum adsorption capacity and dibenzothiophene removal of 14.12 mg/g and 72 %, respectively. Besides, the carbonization temperatures and times during activated carbon preparation have significant effects on the adsorption capacity of sulfur. The oxygen containing surface functional groups on the surface of activated carbon played an important role on the adsorption capacity of dibenzothiophene; while, the physical properties and constituent of activated carbon were not. The adsorption isotherm of dibenzothiophene by activated carbon was related to the Langmuir isotherm.