Abstract
Arsenic pollution is one of important environmental issues in the world. In this study, kaolinite clay coated with titanium oxide-magnetic iron oxide nanoparticles (KC/TiO2-Fe3O4) was synthesized as a new and effective adsorbent by simple precipitation method for influential adsorption of As(III) from the aquatic system. The factorial design method was employed for determining the significance level of the optimized batch experimental parameters. The optimum levels of the parameters in the factorial designing were validated by response surface methodology (RSM) analysis. The isotherm modelling investigations showed that the developed KC/TiO2-Fe3O4 composite had a high monolayer adsorption capacity of 462.0 mg g−1 at optimized conditions, pH 5, sorbent dose (300 mg L−1), initial As(III) concentration (10 mg L−1) and contact time (40 min). Adsorption mechanism based on kinetic evaluations well followed the pseudo-second-order model with higher regression values (>0.99). Adsorption/recovery performance at first, 3rd, 6th and 10th cycles were found to be 92/90 %, 80/77 %, 60/52 % and 20/12 %. All results revealed that the synthesized composite would be promising sorbent for As(III) adsorption from aquatic media due to its beneficial characteristics such as cost-effectiveness, stability, reusable performance and high adsorption capacity.
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•KC/TiO2-Fe3O4 composite was synthesized successfully and characterized.•Experimental parameters effects on As(III) removal were evaluated by CCD method.•As(III) adsorption mechanism was characterized using isotherm and kinetic models.•Composite shows higher adsorption capacity (462 mg g−1) than most of sorbents in literature.