Adsorption of Pb2+and malachite green from water onto a newly developed nanocomposite of bentonite@perovskite Co-Ni oxide@bimetallic Mg/Cu MOFs and their adsorption and kinetic studies

Abstract In this study, an environmentally friendly nanocomposite was synthesized and comprehensively characterized for its potential to adsorb Pb2+ ions and malachite green dye (MG) from aqueous solutions. The composite material was based on nanobentonite intercalated with Ni–Co perovskite oxide and Bimetallic metal–organic frameworks (MOFs) from Bimetallic Mg/Cu, linked with tartaric acid as an organic linker. Structural and chemical properties of the individual components and the final composite were examined using FT-IR, XRD, BET, while TGA was employed to assess thermal stability. SEM analysis provided insights into the surface morphology. The adsorption performance was evaluated under varying pH levels, contact times, adsorbent dosages, and contaminant concentrations. The ultimate adsorption capacity for Pb2+ reached 105.7 mg/g at pH 7.0 with 10.0 mg of adsorbent and a contact time of 5.0 s. For MG, the highest uptake was 14.53 mg/g under optimal conditions of pH 6.0, 20.0 mg/L dye concentration, 20.0-minute contact time, and 10.0 mg of adsorbent.