Wang Ao, Xie Hangang, Xu Hang, Huang Wenwen, Ma Jun, Hu Tianlong, Wang Jingjun, Lin Tao, Ding Mingmei
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China; Suzhou Research Institute, Hohai University, SuZhou 215100, PR China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China.
Water Res. 2025 Sep 1;283:123858. doi: 10.1016/j.watres.2025.123858. Epub 2025 May 17.
Industrial fluoride-laden wastewater has emerged as a critical environmental challenge due to the rapid growth of photovoltaics and battery industries. This study proposes a novel, integrated and expandable fluidized bed-ultrafiltration-reverse osmosis (FBUR) process. The fluidized bed component targets F crystallization, while ultrafiltration (UF) and reverse osmosis (RO) membrane units concentrates fluidized bed effluent. The concentrated brine was recirculated into the fluidized bed to enhance crystallization efficiency, enabling simultaneous water purification and fluorite recovery from photovoltaic wastewater. The effects of Ca dosage, upflow velocity, seed crystal, temperature, pH and water recovery rate on the system were investigated, ultimately achieving 99.7 % F recovery. The optimized process reclaimed water and recovered fluorite of exceptional quality, ensuring that both met high standards. Membrane fouling on UF and RO membranes was characterized using scanning electron microscopy, atomic force microscopy, and optical coherence tomography. Furthermore, the free energy and energy barriers associated with cluster crystallization were calculated based on cluster nucleation theory, and the fouling formation process on the UF membrane surface was analyzed through theoretical computations of the van der Waals-friction-hydrodynamic force field. The results demonstrated that, in the FBUR process, small CaF particles exhibited a tendency to detach from the membrane surface, whereas adhered particles could grow further, ultimately leading to the formation of a loose cake layer. These results emphasize the critical importance of determining optimal concentration effluent levels during transitions between sequential units. This study provides an efficient solution for recovering valuable resources from industrial wastewater, thereby advancing sustainable wastewater management.
由于光伏和电池行业的快速发展，含氟工业废水已成为一项严峻的环境挑战。本研究提出了一种新型、集成且可扩展的流化床-超滤-反渗透（FBUR）工艺。流化床组件旨在实现氟的结晶，而超滤（UF）和反渗透（RO）膜单元则对流化床流出物进行浓缩。浓缩后的盐水被再循环回流到流化床中以提高结晶效率，从而能够从光伏废水中同时实现水净化和萤石回收。研究了钙投加量、上升流速、晶种、温度、pH值和水回收率对该系统的影响，最终实现了99.7%的氟回收率。优化后的工艺回收的水和萤石质量优异，均达到高标准。使用扫描电子显微镜、原子力显微镜和光学相干断层扫描对超滤和反渗透膜上的膜污染进行了表征。此外，基于团簇成核理论计算了与团簇结晶相关的自由能和能垒，并通过范德华力-摩擦力-流体动力场的理论计算分析了超滤膜表面污垢的形成过程。结果表明，在FBUR工艺中，小的氟化钙颗粒有从膜表面脱落的趋势，而附着的颗粒会进一步生长，最终导致形成疏松的滤饼层。这些结果强调了在连续单元之间的转换过程中确定最佳浓缩流出物水平的至关重要性。本研究为从工业废水中回收有价值的资源提供了一种有效解决方案，从而推动可持续废水管理。
