Developing a feasible and efficient separation membrane for the purification of emulsified oily wastewater is challenging due to the critical limitations of serious fouling during membrane preparation. Herein, underwater superoleophobic paper-based materials with high wet strength were prepared by low cost and green papermaking technology. The fibrillation of cellulose fibers was achieved by beating to optimize the pore structure of paper sheets. Simple modification of paper sheets with 1,2,3,4-butanetetracarboxylic acid significantly improves the surface hydrophilicity and the wet strength through the crosslinking reaction between fibers. The maximum underwater oil contact angle and wet strength of the modified paper sheets are high up to 167.8°and 36.5 N·m/g, respectively. The water flux can be adjusted in the range of 25.8 L m⁻² h⁻¹–4920 L m⁻² h⁻¹ by controlling the average pore size from 6.64 μm to 18.9 μm. Lower pore size and higher carboxyl content of the paper-based materials are beneficial to improve the oil rejection, which can reach more than 99.3% even for submicron emulsified oils. Most of the paper sheets achieve efficient oil–water separation although the average pore size is remarkably larger than the emulsified oil droplet. The reason can be attributed to the zigzag pore structure of paper sheets, which is favorable to form liquid bridge on the surface as well as collision demulsification in the Z-direction channel, thereby promoting the mechanical interception effects. The low-cost, eco-friendly, easily-manufactured and highly efficient paper-based separation materials possess wide applications in oily wastewater treatment.

由于膜制备过程中严重污染的严重限制，开发用于乳化含油废水净化的可行且有效的分离膜具有挑战性。在此，采用低成本的绿色造纸技术制备了具有高湿强度的水下超疏油纸基材料。纤维素纤维的原纤化是通过打浆来优化纸张的孔隙结构来实现的。用1,2,3,4-丁烷四羧酸对纸张进行简单改性，通过纤维间的交联反应，显着提高了表面亲水性和湿强度。改性纸的最大水下油接触角和湿强度分别高达167.8°和36.5 N·m/g。水通量可在25.8 L·m范围内调节^-2  h ^-1 –4920 L m ^-2  h ^-1通过控制平均孔径从 6.64 μm 到 18.9 μm。纸基材料较小的孔径和较高的羧基含量有利于提高脱油率，即使是亚微米乳化油也可以达到99.3%以上。尽管平均孔径明显大于乳化油滴，但大多数纸张实现了有效的油水分离。其原因可能是纸张的锯齿形孔结构，有利于在表面形成液桥以及在Z向通道中碰撞破乳，从而促进机械拦截效果。低成本、环保、易制造、高效的纸基分离材料在含油废水处理中有着广泛的应用。