Optimization, Statistical and Adsorption Analysis of Cr(VI) using Corn Industry Sludge: Kinetic and Isotherm Studies

Abstract

Abstract A novel, cost-effective activated carbon was prepared from local corn industry waste sludge to treat chromium (VI) ions from an aqueous solution. Adsorption is one of the promising techniques for treating chromium. The adsorption efficiency depends on temperature, pH, metal ion concentrations, contact time, and adsorbent dose. Activation increase the adsorbent sites on the surface of the adsorbent, and SEM micrographs indicate the adsorption sites before and after adsorption. IR spectrum of FT-IR spectrophotometer was used for analysis Investigation of equilibrium adsorption isotherm data reveals suitability of corn industry waste for treating chromium (VI) ions. The adsorption isotherm and kinetics of chromium (VI) adsorption indicate agreement of the experimental data to Frendulich isotherm and pseudo-second-order model and chemisorption as the reason for Cr(VI) removal. The corn industry waste is thermally activated by heating in a controlled atmosphere at 500° C. Kinetic data studies elucidated that adsorption tracks a pseudo-second-order kinetic model. The maximum adsorption capacity and adsorption efficiency of chromium (VI) were found to be 6.80 mg/g at were pH of 4 with a contact time of 150 min and 91.43% using 1.5 g of adsorbent. The outcomes of corn industry sludge as the advantage of low-cost material and an effective adsorbent for Cr (VI) removal. The statistical analysis of adsorption was studied through response surface methodology (RSM). The experimental and theoretical values for percentage adsorption of Cr were observed as 92.91% and 91.43%, respectively. The experimental results closely agree with the central composite design.