Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou, 215009, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
Environ Res. 2021 May;196:110353. doi: 10.1016/j.envres.2020.110353. Epub 2020 Oct 29.
Integrated ultrafiltration (UF) membrane-based processes are promising drinking water treatment technologies. However, the membrane module always remains static, resulting in membrane fouling through the gradual formation of a thick cake layer. As floc-based cake layers are loose, in the present study, a membrane module spiral rotation was introduced with the aim of regulating the cake layers. The cake layer thickness readily decreased and the UF membrane fouling was alleviated. The results showed that Al-based flocs were not easily removed from the membrane surface during rotation due to its low density; as a result, the likelihood of humic acid (HA) reaching the membrane surface was low. Computational fluid dynamics indicated that a strong shearing force was generated with high rotation height. Thus, the cake layer thickness was easily regulated, and the UF membrane fouling was further alleviated. However, the floc-based cake layer could be broken by strong shearing forces, thereby allowing HA molecules to directly reach the membrane surface and further aggravating membrane fouling. In comparison to alkaline condition, the UF membrane performed better under acidic conditions, particularly in terms of HA removal, due to the smaller floc size and higher positive charge. Additionally, excellent UF membrane performance was also observed when treating raw water, indicating the potential application.
基于集成超滤（UF）膜的工艺是很有前途的饮用水处理技术。然而，膜组件始终保持静止，导致通过逐渐形成厚的饼层而发生膜污染。由于基于絮体的饼层是松散的，因此在本研究中，引入了膜组件螺旋旋转以调节饼层。膜污染迅速减轻，膜通量恢复良好。结果表明，由于其低密度，旋转过程中 Al 基絮体不易从膜表面去除，因此到达膜表面的腐殖酸（HA）的可能性较低。计算流体动力学表明，高旋转高度会产生很强的剪切力。因此，很容易调节饼层厚度，进一步减轻 UF 膜的污染。但是，絮体基饼层可能会被强剪切力破坏，从而允许 HA 分子直接到达膜表面，进一步加剧膜污染。与碱性条件相比，UF 膜在酸性条件下表现更好，尤其是在去除 HA 方面，因为絮体尺寸更小，正电荷更高。此外，处理原水时也观察到了出色的 UF 膜性能，表明了其潜在的应用。
