Sustainable sodium alginate hydrogels incorporating banana leaf activated carbon and organo-clay for enhanced dye removal

Abstract

New sodium alginate-based hydrogels using activated carbon from banana leaves and organo-modified montmorillonite for water treatment. Activated carbon extracted successfully from banana leaves and montmorillonite clay was surface-modified using cetyltrimethylammonium bromide as a cationic surfactant. Hydrogels were then synthesized using calcium chloride as the cross-linking agent. They were characterized using FTIR, X-ray diffraction, and scanning electronic microscopy. Characterization intimated the incorporation of components successfully. Adsorption performance was determined using pH, adsorbent dosages, initial dye concentration, and contact time. Sodium alginate-based hydrogels demonstrated remarkable efficacy in removing MB and EBT dyes from synthetic solutions, achieving removal efficiencies of up to 80.3% and 84.9% respectively within 90 min at pH 7. The adsorption process corresponded better to the Freundlich isotherm model. The kinetics of EBT dye removal were described by a pseudo-second-order model. Meanwhile, the kinetics of the removal of MB dyes were described by both pseudo-first order and intraparticle diffusion models. We conducted MTT assays to determine the cytotoxicity of our blends. This showed a dose-dependent drop in viability. Sodium alginate-based hydrogels made the cells least cytotoxic. The developed hydrogels can be used as safe and effective agents for water treatment, as indicated by the results.