Adsorption Mechanism of Lead on Wood/Nano-Manganese Oxide Composite

Discharge of untreated industrial wastewater containing heavy metals such as Pb۲+ is hazardous to the environment due to their high toxicity. This study reports on the adsorption, desorption, and kinetic study on Pb۲+ removal from aqueous solutions using wood/Nano-manganese oxide composite (WB-NMO). The optimum pH, contact time and temperature for adsorption were found to be ۵.۰, ۴ h and ۳۳۳ K, respectively. Pseudo-second-order kinetics best described the adsorption process with an initial sorption rate of ۴.۰ mg g min-۱, and a half-adsorption time t۱/۲ of ۳۱.۶ min. Best fit for adsorption isotherm was obtained with the Brunauer-Emmett-Teller (BET) model with a maximum adsorption capacity of ۲۱۳ mg/g for an initial metal concentration of ۶۰ mg/L. Both intra-particle diffusion and film diffusion contribute to the rate-determining step. Desorption experiments with ۰.۵ mol/L HCl, inferred the reusability of the composite. Adsorption experiment of Pb۲+ from industrial wastewater confirmed that the prepared WB-NMO is a promising candidate for wastewater treatment. The WB-NMO demonstrated high Pb۲+ removal efficiency and is considered as a promising alternative and reusable composite for lead removal from contaminated effluents.

کلیدواژه ها:

wood ، Manganese oxide ، Adsorption ، Kinetics ، Lead