A magnetic macroporous α-Fe2O3/Mn2O3 nanocomposite as an efficient adsorbent for simple and rapid removal of Pb(II) from wastewater and electronic waste leachate.

Abstract

A magnetic nanocomposite adsorbent, comprised of macroporous iron oxide/manganese oxide (α-Fe₂O₃/Mn₂O₃), is prepared, characterized, and used for lead(II) removal from both industrial wastewater and leachate of electronic waste. The synergistic interaction between iron oxide and manganese oxide significantly enhances the adsorption performance. The surface characteristics and structural composition of the nanocomposite are examined using high-resolution transmission microscopy, X-ray spectroscopy, and Brunauer-Emmett-Teller methods. Under optimized conditions, the present method offers a significantly high adsorption capacity (377.5 ± 8.9 mg.g^-1), short contact time (10 min), and an excellent removal efficiency (98.0 ± 0.9%) compared with most of the previously suggested methods. The adsorption kinetics of Pb(II) on the nanocomposite surface follows pseudo-second-order kinetics and exhibits a good fit with the Dubinin-Radushkevich (D-R) model. These findings highlight the applicability of the α-Fe₂O₃/Mn₂O₃ magnetic nanocomposite as a promising efficient adsorbent for the rapid removal of lead(II) from hazardous wastewater. Moreover, the proposed nanocomposite adsorbent exhibits remarkable stability and can be easily isolated from the test sample solution for subsequent reuse. The efficacy of the developed adsorptive removal procedure is confirmed by achieving a complete lead(II) ion removal from some industrial wastewater discharged from lead battery factories and from the leachate of electronic waste.