Facile and green fabrication of porous chitosan aerogels for highly efficient oil/water separation and metal ions removal from water

Recently, bio-based materials from natural source have attracted more attention in water treatment, but the viable usage of bio-based materials is a new challenge in the treatment of increasingly complicated water pollution. The multifunctional bio-based materials with high performance are desired to be obtained. In this study, chitosan aerogels with three dimensional (3D) interconnected porous architectures were designed and prepared through a feasible and facile strategy, that is, the integration of chitosan gelation and microbubble templates. With the assistance of ultrasound technology, abundant microbubbles were generated and solidified into chitosan gel. As anticipated, the porous chitosan aerogels exhibited the robust superhydrophilicity/underwater oleophobicity and low-adhesion performance, displaying the high-efficiency selective separation for various oil-water mixtures. Moreover, origination from the interconnected porous architectures, not only high permeation flux was achieved during oil/water separation, but also copper ions can be adsorbed from water more quickly by this material, with high adsorption capacity (116.7 mg/g). Consequently, the oil contaminants and copper ions can be energy-savingly removed from wastewater simultaneously. The facile and green fabrication process of porous chitosan aerogels provides a feasible avenue to prepare bio-based materials with outstanding performances, while it opens up new prospects for the high-efficiency complicated wastewater treatment.