Regenerated cellulose/chitosan composite aerogel with highly efficient adsorption for anionic dyes

A novel reusable, high-compressible cotton regenerated cellulose/chitosan composite aerogel (RC/CSCA) was prepared using N-methylmorpholine-N-oxide (NMMO) as the green cellulose solvent, and glutaraldehyde (GA) as the crosslinking agent. The regenerated cellulose obtained from cotton pulp could chemically crosslink with chitosan and GA, to form a stable 3D porous structure. The GA played an essential role in preventing shrinkage and preserving the deformation recovery ability of RC/CSCA. Due to the ultralow density (13.92 mg/cm3), thermal stability (above 300 °C), and high porosity (97.36 %), the positively charged RC/CSCA can be used as a novel biocomposite adsorbent for effective and selective removal of toxic anionic dyes from wastewater, showing an excellent adsorption capacity, environmental adaptability, and recyclability. The maximal adsorption capacity and removal efficiency of RC/CSCA for methyl orange (MO) was 742.68 mg/g and 95.83 %.