Bentonite-Chitosan composites or beads for lead (Pb) adsorption: Design, preparation, and characterisation

• DOI: 10.1016/j.clay.2023.107180
• Publication Date: 2023-10-31T13:37:37Z
• Authors: Hassan Majiya; Francis Clegg; Chris Sammon
• Keywords: Bentonite; Thermogravimetric analysis; Bead

This study investigated the efficiency of mixing bentonite with chitosan via different preparation methods, subsequently forms were for their ability to remove Pb(II) ions from solution. The bentonite-chitosan (Bt-Ch), composites and beads, prepared solution blending precipitation respectively in weight ratios 90%/10%, 70%/30% 50%/50%. beads further subdivided, identified as "beads-A" "beads-B", formed by adding either suspension or powder, respectively, solubilised characterised X-ray fluorescence (XRF), thermogravimetric analysis (TGA), diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) pH at zero point charge. XRF showed a cation exchange mechanism occurred when was initially mixed bentonite. TGA results confirmed that contained more compared corresponding ratio equivalent composites. XRD intercalated within interlayer space Bt-Ch beads-A spacings increased increasing loading. Though similar amounts present both beads-B, there fewer reflection shifts B suggesting less intercalation added powder. FTIR spectra presence bentonite, NH bands shifted lower frequencies demonstrating involvement bonding experimental adsorption data correlated well non-linear Langmuir Freundlich isotherm models, which chemisorption physisorption processes played crucial roles. Langmuir-maximum capacities all analysed found range 42.48 ± 4.22 94.60 5.63 mg/g. amount adsorbent its distribution outside shown have pronounced effects on uptake composites/beads, although greatly enhanced clay still dominant process. also significantly affected other multi-competing ions. Moreover, developed composites/beads exhibited good potential re-use after five cycles regeneration, thus, indicating cost-effective adsorbents removal drinking wastewater.