Hydrophilic high strength polyvinyl alcohol-based (H-ZSM-5/PVA@SSM) hydrogels for oil-water/emulsion separation

Oily wastewater discharge severely endangers ecology and human health, driving demand for oil-water separation materials with high efficiency and environmental friendliness. In this study, the H-ZSM-5 molecular sieves were incorporated into PVA matrix and loaded onto stainless steel mesh (SSM) to construct H-ZSM-5/PVA@SSM composite hydrogel separation material. H-ZSM-5 builds continuous water transport channels for large water flux, increases surface roughness on composite hydrogels to form stable hydration layers and improve oil resistance, while hydrogen bonding reinforces adhesion with PVA matrix. Meanwhile, the SSM as rigid supporting framework offers steady mechanical support for hydrogel coating, and effectively improve material mechanical strength and reusability. The optimal H-ZSM-5/PVA-0.5@SSM sample achieves markedly increased water flux rising from 113.04 L m −2  h −1 (PVA@SSM) to 735.82 L m −2  h −1 , while maintaining separation efficiency above 96% after 30 cycles. Besides, the material gains oil-in-water emulsion separation efficiency up to 99.80% with water flux of 1.086 × 10 5  L m −2  h −1  bar −1 . Also, the H-ZSM-5/PVA-0.5 composite hydrogel gains tensile strength enhancement from 22.16 MPa to 26.97 MPa compared to pristine PVA hydrogel. By integrating H-ZSM-5 porous transport merit, PVA hydrophilicity and SSM rigid support, the H-ZSM-5/PVA-0.5@SSM achieves efficient purification of oily wastewater and emulsions.