Full-factorial design and mathematical models of fixed-bed column adsorption of hexavalent chromium by S. glauca

Abstract The effective removal of hexavalent chromium is a very important issue for many countries. There is rising interest in the use of inexpensive and widely accessible materials for the adsorption of Cr (VI). Simarouba glauca, a easily available medicinal plant was found to be very effective in removing Cr(VI) from aqueous medium. First part of the study deals with the implementation of 25 Full factorial design technique to investigate adsorption of Cr(VI) onto S. glauca. It aided in the assessment of the main effects and interactions between the dose of S. glauca, pH, temperature, initial Cr(VI) concentration, and time. The adsorption significance was predicted through ANOVA, T-Test, Pareto chart, main effect and interaction plot. The second part of the study deals with the investigating potential of S. glauca by continuous adsorption mode in a fixed-bed column. The effects of Cr(VI) inlet concentration (50,100,150 mg/L), flow rate (13 and 21 mL/min) an S. glauca bed height (30, 36, 40 and 45 cm) on the breakthrough characteristics of the adsorption system were determined. The highest bed capacity of 611.69 mg/g was obtained using 100 mg/L inlet Cr(VI) concentration, 45 cm bed height and 13 mL/min flow rate. Three well-known fixed-bed adsorption models, the Thomas, Yoon-Nelson models and Adam's-Bohart were used to match the adsorption data. With correlation coefficients of 0.99 under various circumstances, the results suit the Thomas and Yoon-Nelson models well. According to this study, we may utilise this method to remediate chromium-contaminated water in industrial settings.