ZIF-8 Enhanced Superwettable Cellulose Hydrogel-Coated Mesh for Efficient Oil–Water Separation

In recent years, water pollution caused by oily wastewater discharged from industrial production has become increasingly serious. There was an urgent need for a simple, efficient, and environmentally friendly method to treat oily wastewater, so as to reduce and solve the water pollution problem. In this study, a layer of cellulose hydrogel was coated on stainless steel mesh (SSM) by a dipping coating method, and nanozeolitic imidazolate framework-8 (ZIF-8) particles were grown in situ using the hydrogel as the matrix. The surface roughness of cellulose@ZIF-8@SSM was improved, and its hydration ability was enhanced. The prepared superhydrophilic-underwater superoleophobic cellulose@ZIF-8@SSM can separate different oil/water mixtures under gravity and has long-term separation ability. What is more, the oil–water separation efficiency was more than 99.997%. In addition, cellulose@ZIF-8@SSM showed good chemical and mechanical stability in acid and alkali solution immersion and sand impact tests. This work has broad application prospects and potential in the field of treating oily wastewater.