Separable alginate gel spheres encapsulated with La-Fe modified biochar for efficient adsorption of Sb(III) with high capacity

Sb and its compounds have been widely used in various industrial applications. Therefore, the preparation of Sb adsorbents with easy recovery and excellent adsorption levels is an urgent problem that must be resolved. By calcining and treating La/Fe metal–organic frameworks (MOF) biochar as a precursor, a loaded La-Fe-modified water hyacinth biochar was synthesised and used as a filler to synthesise iron alginate composite gel spheres, MBC/algFe. Through a series of static adsorption experiments, the effects of different filler addition ratios, solution pH, reaction time, coexisting ions, and other factors on the adsorption of Sb(III) were investigated. According to the Langmuir model, the maximum adsorption capacity of MBC/algFe at 25 ℃ was 277.8 mg·g−1. The adsorption mechanism mainly involved hydrogen bonding and metal-organic complexation interactions. [Display omitted] •A simple method was used to prepare La-Fe modified biochar/alginate beads.•The maximum Sb(III) adsorption capacity was up to 277.8 mg·g−1 at 25 ℃.•MBC/algFe had a good affinity for Sb(III) and anti-interference ability.•Removal mechanism contains both hydrogen bonding and metal-organic.