Optimization Studies for Chromium (VI) Removal using Agro-Industrial Wastes.

The heavy metals released from various industries are toxic to the environment even at minute concentration. Box-Behnken design is the Response Surface Methodology (RSM) tool used to model higher order response surfaces using lesser experimental trials than a normal factorial technique. The current study, involves the application of Box-Behnken experimental design in evaluating and optimizing the Hexavalent Chromium [Cr(VI)] removal using agricultural industrial wastes as adsorbents. The effect of process variables such as pH (2-9), adsorbent dosage (0.1-3g) and initial Cr(VI) concentration (50-100 mg/L) on the industrial wastes are evaluated. The saw palmeto extract exhibited maximum chromium removal at a pH of 2 with 1g biomass dosage and at an initial metal ion concentration of 100 ppm. Similarly, the maximum Cr(VI) removal efficiency using waste of black cumin extract was observed with 2g biomass dosage at an initial metal ion concentration of 60 ppm for a pH value 2. The maximum chromium removal using waste of ginger root extract was observed with 2g biomass dosage at an initial metal ion concentration of 60 ppm for a pH value 2. The RSM technique provided a mathematical model which helped in determining the interactions between various process variables which affected the removal efficiency of Cr(VI). [ABSTRACT FROM AUTHOR]