removal of dibenzothiophene using activated carbon/γ-fe2o3 nano-composite: kinetic and thermodynamic investigation of the removal process

in the present study, removal of dibenzothiophene (dbt) from model oil (n-hexane) was investigated using magnetic activated carbon (mac) nano-composite adsorbent. the synthesized nano-composite was characterized by ft-ir, fe-sem, bet and vsm techniques. the mac nano-composite exhibited a nearly superparamagnetic property with a saturation magnetization (ms) of 29.2 emu g-1, which made it desirable for separation under an external magnetic field. the magnetic adsorbent afforded a maximum adsorption capacity of 38.0 mg dbt g-1 at the optimized conditions (adsorbent dose, 8 g l-1; contact time, 1 h; temperature, 25 °c). langmuir, freundlich and temkin isotherm models were used to fit equilibrium data for mac nano-composite. adsorption process could be well described by the langmuir model. kinetic studies were carried out and showed the sorption kinetics of dbt was best described by a pseudo-second-order kinetic model. in addition, the mac nano-composite exhibited good capability of recycling to adsorb dbt in gasoline deep desulfurization.