Abstract:

Membrane distillation technology has broad application space in fields of hypersaline wastewater treatment, high-value salt recovery and freshwater extraction. Until now, membrane distillation technology has not been widely promoted and applied yet for various reasons, among which membrane fouling is particularly prominent. Special wettable membrane has been recognized as an effective way to alleviate fouling in membrane distillation. Therefore, this article mainly reviewed the research progress on the antifouling characteristics of special wettable porous membranes from several aspects, e.g. the theoretical models of special wettable surfaces, membrane preparation and antifouling characteristics. Firstly, a brief introduction was given to membrane distillation technology and the types and processes of membrane fouling in membrane distillation, while the research hotspots and publications related to membrane distillation and membrane fouling in the past five years were discussed. Secondly, the fabrication principles of special wettable surfaces were systematically elaborated based on the Young model, Wenzel model and Cassie-Baster model. The design, fabrication and antifouling characteristics of special wettable porous membranes were illustrated with examples. Finally, the difficulties and challenges for the application of special wettable porous membrane in antifouling membrane distillation were raised, including complex preparation processes, fragile micro/nano structures, lack of low surface energy materials and inconsistent evaluation standards. The development of special wettable porous membranes with low toxicity, low cost, broad-spectrum antifouling ability, and acid and alkali resistance would become a key research direction.

Key words: membrane distillation, special wettability, membrane fouling, superhydrophobic, membrane scaling

摘要：

膜蒸馏技术在高盐度废水处理、高价值盐分收回和高纯度水资源汲取等领域具有广阔的应用空间。目前，膜蒸馏技术尚未被大规模推广应用，究其原因是多方面的，其中膜污染问题尤为突出，而特殊浸润性膜表面的构筑是公认的缓解膜污染问题的有效途径。因此，本文主要从特殊浸润性表面理论模型、膜制备和膜抗污染特性等几个方面，综述了特殊浸润性多孔膜在膜蒸馏中的抗污染特性研究进展。首先，简单介绍了膜蒸馏技术和膜蒸馏操作中的膜污染类型、过程，比较了近五年膜蒸馏与膜污染相关研究热点和发文量；其次，基于Young模型、Wenzel模型和Cassie-Baster模型系统阐述了特殊浸润性表面的构筑原则，举例说明了特殊浸润性多孔膜的设计制备及其抗污染特性；最后，提出特殊浸润性多孔膜应用于抗污染膜蒸馏尚存在的困难和挑战，包括制备工艺较复杂、微纳米结构较脆弱、低表面能材料较单一、评价标准不统一等。低毒、低成本、广谱抗污染、耐酸碱等特殊浸润性多孔膜的开发将成为重点研究方向。

关键词: 膜蒸馏, 特殊浸润性, 膜污染, 超疏水, 膜结垢