Adsorptive desulphurization of model oil by Ag nanoparticles-modified activated carbon prepared from brewer’s spent grains

摘要

This study reports removal of dibenzothiophene (DBT) from model oil (DBT dissolved in n-heptane) byudsilver nanoparticles modified activated carbon prepared from brewer’s spent grains using wetudimpregnation (WI) method. The removal efficiency follows the order AgNPscw=AC > AgNPskp=AC> ACB.udThe AgNPskp/AC and AgNPscw/AC exhibit higher adsorption capacities for DBT with maximum values ofud25.7 and 29.8 mg DBT/gAds at 25 �C respectively, than ACB with 13.9 mg DBT/gAds. The two-foldudenhancement in the DBT uptake capacities of modified ACs can be attributed to the introduction of Ag(1)udion, a weak Lewis acid as an additional adsorption site. A significant decrease from 212.9 to 136.2 m2/g inudthe Brunauer–Emmett–Teller surface area of AgNPscw/AC is observed following the loading of DBT. Theudequilibrium adsorption data is adequately represented by Freundlich isotherm. The adsorption kinetics ofudDBT by these adsorbents followed pseudo second-order (PSO) model and the mechanism of adsorptionudwas controlled byudfilm and intra-particle diffusion. The change in entropy and heat of adsorption for DBTudadsorption by these adsorbents range from 0.18 to 0.19 kJ/mol K and 21.5 to 23.9 kJ/mol, respectively. Theudresults indicate that Ag nanoparticles-modified ACs from brewer’s spent grains can be used as adsorbentudfor the removal of DBT from model oil.