A versatile bio-based material for efficiently removing toxic dyes, heavy metal ions and emulsified oil droplets from water simultaneously

•A versatile bio-based material was prepared by a simple method.•Various kinds of pollutants could be simultaneously removed from water.•The removal efficiency of this material was high.•This material could be recycled for 10 times without reduction of efficiency.

Developing versatile materials for effective water purification is significant for environment and water source protection. Herein, a versatile bio-based material (CH-PAA-T) was reported by simple thermal cross-linking chitosan and polyacrylic acid which exhibits excellent performances for removing insoluble oil, soluble toxic dyes and heavy metal ions from water, simultaneously. The adsorption capacities are 990.1 mg g−1 for methylene blue (MB) and 135.9 mg g−1 for Cu2+, which are higher than most of present advanced absorbents. The adsorption towards organic dyes possesses high selectivity which makes CH-PAA-T be able to efficiently separate dye mixtures. The stable superoleophobicity under water endows CH-PAA-T good performance to separate toluene-in-water emulsion stabilized by Tween 80. Moreover, CH-PAA-T can be recycled for 10 times with negligible reduction of efficiency. Such versatile bio-based material is a potential candidate for water purification.