Enhanced chromium (VI) removal using activated carbon modified by zero valent iron and silver bimetallic nanoparticles

Recently, adsorption process has been introduced as a favorable and effective technique for the removal of metalions from aqueous solutions. in the present study, bimetallic nanoparticles consisting of zero valent iron and silverwere loaded on the activated carbon powder for the preparation of a new adsorbent (pac-feo/ag). the aboveadsorbent was characterized by using xrd, sem and tem techniqes. experimental data were exploited for kinetic,equilibrium and thermodynamic evaluations related to the adsorption processes. the cr(vi) adsorption process wasfound to be favorable at ph 3 and it reached equilibrium state within 60 min. the stirring rate did not have asignificant effect on the adsorption efficiency. furthermore, the monolayer adsorption capacity of cr(vi) based onthe langmuir model was measured to be 100 mg/g. the experimental equilibrium data were fitted to thefreundlich adsorption and pseudo second-order models. according to the thermodynamic study, the adsorptionprocess was spontaneous and endothermic in nature, indicating the adsorption capacity increases with increasingthe temperature. the results also revealed that the synthesized composite can be potentially applied as a magneticadsorbent to remove cr(vi) contaminants from aqueous solutions.