A wood-derived nanocellulose aerogel developed by optimized freeze-drying for adsorbing microplastics and dyes

A wood-derived aerogel with charged functional groups and unidirectional pores was prepared for microplastics and dyes adsorption. The unidirectional freezing combined with the SiC-assisted microwave heating was employed to achieve the optimization of freeze-drying (FD). The results demonstrated that the optimized FD strategy could save the drying time by more than 43%. Meanwhile, this strategy imparted ordered pores in the aerogel, thereby improving the mechanical property. The prepared aerogel showed robust performance across a broad range of pH values and had high maximum adsorption capacities of 558.37, 433.13, and 863.35 mg·g^-1 for microplastics, methylene blue, and Congo red, respectively. Moreover, the aerogel exhibited notable recyclability over 10 cycles, and had the ability to simultaneously remove PM plus dyes in binary pollutant systems. The research results provide a promising pathway for the sustainable utilization of forestry resource in the treatment of wastewater contaminated with microplastics and dyes.