Investigation of the efficacy of Pb(II) and Cd(II) ions biosorption by the Corn bran: Study equilibrium and thermodynamic parameters

This study focuses on investigating the efficacy of corn bran, serving as a natural biosorbent, in the biosorption of Pb(II) and Cd(II) ions. The FTIR, XRD, SEM, and pHpzc were used to characterize the biosorbent. The aim of examining the impact of contact time, pH, biosorbent dose, initial concentration, and temperature was to thoroughly comprehend how these factors affect the biosorption process. The equilibrium was defined through the Langmuir and the Freundlich isotherm models. The Langmuir model exhibited a satisfactory linear correlation (R2 = 0.999 for Pb and R2 = 0.989 for Cd), than the Frundlich isotherm. At the optimal conditions for each metal, the maximum loading capacity (qmax) was 40.98 mg/g and 29.41 mg/g for Pb(II) and Cd(II) ions, respectively. These results emphasize the possibility of utilizing corn bran as a low-cost and eco-friendly material for removing lead and cadmium ions. The biosorption capacity of lead and cadmium ions in a single system was higher than in a binary system, at optimum conditions. Over 99.18 % and 97.54 % of lead and cadmium ions were successfully recovered through desorption using 0.5M HNO3. The examination of thermodynamic parameters (ΔHo, ΔSo, and ΔGo) suggests that the biosorption process is exothermic, spontaneous, and favorable.