A B S T R A C TThe adsorption of benzothiophene sulfone and dibenzothiophene sulfone from diesel using six different types of adsorbents were investigated. Adsorbents used were commercial adsorbents granular-activated carbon (GAC), aluminum oxide (ALU), novel adsorbents chitosancoated bentonite (CHB), and metal-ion impregnated activated carbons, where there types of metal ions, Cu 2+ , Fe 3+ , and Ni 2+ , were loaded (Cu 2+ /AC, Fe 3+ /AC, Ni 2+ /AC). Kinetic studies conducted showed that the adsorption process followed a pseudo-second-order kinetics. Equilibrium studies indicated that the heterogeneous and homogenous monolayer adsorption and are present in the process. Moreover, based on the results of sulfone removal using the synthetic diesel fuel, increasing removal efficiencies of Benzothiophene sulfone followed the order of ALU < GAC < Cu 2+ /AC < < Fe 3+ /AC < CHB, while for dibenzothiophene sulfone (DBTO) removal, increasing DBTO removed efficiencies followed the order of GAC < CHB < ALU < Cu 2+ /AC % Fe 3+ /AC % Ni 2+ /AC.

The adsorption of benzothiophene sulfone (BTO) and dibenzothiophene sulfone (DBTO) from model diesel fuel were evaluated using granular activated carbon (GAC) and modified activated carbon. Modified activated carbon was impregnated with metal ions, Cu 2+ , Fe 3+ , and Ni 2+ , and the effect on its adsorption characteristics was determined. Adsorption performance was investigated using batch process at room temperature and agitation speed of 120 rpm. Results indicated a significant increase in the adsorption capacity compared to that of the unmodified GAC. Increasing adsorption capacity followed the order Cu 2+ /AC < Ni 2+ /AC < Fe 3+ /AC for BTO, whereas for DBTO, increasing order is Ni 2+ /AC < Fe 3+ /AC < Cu 2+ /AC. Evaluation of equilibrium isotherms using Langmuir and Freundlich models yielded a good fit with values of R 2 > 0.90. Adsorption process seemed to proceed in a two-step process. First, a very fast rate for the first few minutes, then a markedly reduced rate until equilibrium is reached. All the adsorbents used have several functional groups present on its surface, and it is the nature of these surface groups that determine the character of these adsorbents.