Efficient removal of Cr6+ from aqueous medium by gelling based-composite: Adsorption mechanisms and characterization studies

The current research investigated the adsorption of Cr6+ from aqueous medium using gelling based-composite materials in a batch mode method. The effects of different experimental parameters, such as pH, gelling-based composite dosage, experimental times, and adsorbate concentrations with constant room temperature were studied systematically to evaluate the removal efficiency. The residual composite materials after adsorption were characterized using different instrumental techniques. The removal mechanisms of Cr6+ ions were evaluated using isotherm, kinetic, and column studies. The maximum removal capacity by treated gelling-based composite was found to be 80 mg/g at the optimum conditions of pH 6.5, exposed time of 70 min, composite dosage of 7.0 gL−1 and temperature of 30°C. The Langmuir isotherm and pseudo-second order kinetic model provided best results in comparison with other models. Column method is performed to know the breakthrough point with specific bed height and initial concentration of chromium solution. Regeneration studies reveal that the adsorbent can be regenerated by using different concentration of H2SO4.