Fabrication of multifunctional biomass-based aerogel with 3D hierarchical porous structure from waste reed for the synergetic adsorption of dyes and heavy metal ions

Abstract

The serious environmental pollution and ecological risks caused by dyeing wastewater and waste reed is the urgent problem to be solved. Here, a multifunctional biomass-based aerogel (CE/CSA) was synthesized using cellulose (CE, extracted from waste reed) and chitosan (CS), and it exhibited abundant three - dimensional (3D) hierarchical porous structure with low density (0.062 g/cm3). The maximum adsorption amount of CE/CSA-1 for Congo red (CR) and Cu2+ was 380.23 mg/g and 260.41 mg/g when they coexisted in water, which increase by 49.05 % and 28.64 % compared with that in the single system, respectively. The result suggested that the preloaded CR could provide new adsorption sites (–NH2/-SO3-) to bridge free Cu2+ in the solution. Likewise, the preabsorbed Cu2+ had the same mutual bridging effect toward free CR, which achieved a synergistic effect between CR and Cu2+ onto CE/CSA-1. Furthermore, the fixed-bed column adsorption experiments for CR demonstrated the adsorption amount of CE/CSA-1 was reached to 241.00 mg/g, and the breakthrough curves were fitted by the Thomas and Yoon-Nelson models. Therefore, the as-prepared biomass-based aerogel derived from waste reed can be considered as a promising adsorbent for the treatment of dyeing wastewater including dyes and heavy metal ions.