School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada.
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
Chemosphere. 2023 Jul;330:138706. doi: 10.1016/j.chemosphere.2023.138706. Epub 2023 Apr 15.
The discharge of oily wastewater has increased dramatically and will bring serious environmental problems. In this work, a self-cleaning and anti-fouling g-CN/TiO/PVDF composite membrane was fabricated via the layer-by-layer approach. The surface of as-prepared composite membrane displayed a superhydrophilic and underwater superoleophobic behavior under irradiation with visible light. Also, upon irradiation with visible light, the fabricated g-CN/TiO/PVDF composite membrane displayed enhanced permeation flux and improved oil removal efficiency as a result of the generation of hydroxyl free radicals during the photocatalytic filtration process. Significantly, irradiation with visible light remarkably improved reusability of the composite membrane by initiating photocatalytic decomposition of deposited oil foulants, which enabled removal of over 99.75% of oils, thus reaching a nearly 100% flux recovery ratio. Furthermore, the g-CN/TiO/PVDF composite membrane exhibited great anti-fouling behavior in photocatalysis-assisted filtration. The mechanistic study revealed that underwater superhydrophobicity and the generation of free hydroxyl radicals jointly contributed to membrane anti-fouling. The greatest advantages of this g-CN/TiO/PVDF composite membrane are that not only does it degrades the oil pollutants, but it also makes the membrane less vulnerable to fouling.
含油废水排放量大幅增加，将带来严重的环境问题。在这项工作中，通过层层自组装法制备了一种自清洁和抗污的 g-CN/TiO/PVDF 复合膜。在可见光照射下，所制备的复合膜表面表现出超亲水和水下超疏油性。此外，在可见光照射下，由于光催化过滤过程中产生羟基自由基，所制备的 g-CN/TiO/PVDF 复合膜的渗透通量得到提高，除油效率得到改善。值得注意的是，可见光的照射通过引发沉积油污染物的光催化分解，显著提高了复合膜的可重复使用性，从而去除了超过 99.75%的油，通量恢复率接近 100%。此外，g-CN/TiO/PVDF 复合膜在光催化辅助过滤中表现出良好的抗污染性能。机理研究表明，水下超疏水性和游离羟基自由基的产生共同导致了膜的抗污染性能。这种 g-CN/TiO/PVDF 复合膜的最大优点是不仅可以降解油污染物，而且还可以降低膜的污染程度。
