Adsorption of hexavalent chromium by Simarouba glauca in a fixed-bed column: a full-factorial design and mathematical modelling

Abstract

ABSTRACT Due to its high toxicity and mobility, hexavalent chromium must be adequately eliminated from effluent or wastewater. For Cr(VI) adsorption, it is increasingly becoming customary to use inexpensive, readily accessible plant-based materials. It has been discovered that the popular medicinal herb Simarouba glauca is quite effective at removing Cr(VI) from aqueous media. The first stage of this study examines Cr(VI) adsorption onto S. glauca using the 25 Full Factorial Design technique. It was possible to determine the major effects of S. glauca dosage and how they interacted with pH, temperature, the initial Cr(VI) concentration, and time. The adsorption was predicted adequately with the aid of ANOVA, t-test, Pareto charts, main effect, and interaction plots. The second section of the study focuses on the potential for continuous adsorption of S. glauca in a fixed-bed column. The Cr(VI) inlet concentration (50, 100 and 150 mg/L), flow rate (13 and 21 mL/min), and S. glauca bed height (30, 36, 40 and 45 cm) all had an impact on the breakthrough qualities of the adsorption system. The fixed-bed adsorption models of Thomas, Yoon–Nelson, and Adams-Bohart were used to fit the adsorption data. The Thomas model, with a flow rate of 13 mL/min, a bed height of 45 cm and an inlet concentration of 100 mg/L of Cr(VI), calculated the adsorption capacity to be 611.6 mg/g with a coefficient of 0.99. The findings are consistent with the hypotheses advanced by Thomas and Yoon–Nelson. This study suggests that this technique could be used to treat chromium-contaminated water in industrial settings.