Fe3O4/SiO2/polymer hybrid biosorbent based on an etch-fill strategy for heavy metal ion adsorption

Heavy metal contamination is a serious concern worldwide. In order to remove heavy metal ions from wastewater efficiently, multifunctinoal biomass-based material have been utilized. Herein, hyperbranched polymer modified cellulose biomass (HBP-CB) derived from textile waste materials ramie fibers was successfully developed by construction of Fe3O4/SiO2/polymer multiple structure through an etch-fill strategy. Specifically, Fe3O4 and SiO2 particles were introduced to the oxidation etching cellulose surface, and subsequently modified by hyperbranched polymer The adsorption behavior of the adsorbent toward two classes of heavy metal ions was investigated. The results indicated that HBP-CB owned excellent adsorption capacities for chromium and Cu(II) with maximum 123.5 mg/g and 149.0 mg/g and magnetic recovery performance in aqueous medium. These are owing to the oxidization etching biomass matrix with a higher BET surface area of 4.61 m2/g and the hybrid multiple structure modified by functional hyperbranched polymer with high dense adsorptive sites on the matrix. The adsorption behavior was well described by pseudo-second-order kinetic model and Langmuir isotherm model, revealing a rapid surface adsorption and monolayer spontaneous chemical adsorption. For recycling, 81% of adsorption capacity could be retained after five recovery cycles. These demonstrate that the hybrid multiple structure based on biomass, nanomaterials and polymer could provide sustainable and high-performance adsorption property for wastewater treatment.