Sustainable oil-water separation and pollutant degradation with ZnO-doped wood aerogels

The development of the petrochemical industry necessitates the treatment of oily industrial wastewater. Addressing the separation, recovery, and reuse of oily wastewater with low-cost, high-efficiency, and environmentally friendly methods has become a significant focus in environmental protection. The search for oil-water separation materials with specific functionality and environmental durability is now a priority. In this study, natural wood was delignified, and ZnO nanoparticles were grown within the wood aerogel to create a functionalized nano-composite wood aerogel. The porous ZnO/DW aerogels exhibited an average adsorption capacity of 17.66 g g −1 . Due to the presence of a hydration shell formed by hydrogen bonding, the water-saturated ZnO/DW aerogel exhibits hydrophilic and oleophobic properties. The separation device achieved a water flux of 39,400 L m −2 h −1 and a separation efficiency of over 98.5 %, effectively facilitating oil-water separation. Furthermore, the synergistic effect of ZnO nanoparticles and wood aerogels resulted in the photocatalytic degradation of methylene blue in solution by up to 92.94 %. The cycle tests show the excellent stability of the sample in compression-release cycle, adsorption-extrusion cycle and photocatalytic degradation cycle.