Membrane fouling in ultrafiltration of latex paint

乳胶漆超滤中的膜污染

• 批准号: 216939-2013
• 负责人: Doan, Huu
• 金额: $ 1.6万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649389
• 关键词: Membrane; fouling; ultrafiltration; latex; paint

Ultrafiltration (UF) is a membrane separation process used in a wide range of applications, such as: water/wastewater treatment, water pre-treatment for reverse osmosis, separations in food, chemical and biochemical industries. With the developement of low-pressure membranes, membrane applications, including ultrafiltration, have been growing exponentially in recent years. However, a major challenge in the application of ultrafiltration is membrane fouling by the solutes in the feed solution. Membrane fouling causes a reduction of the filtrate flux with time, and hence, a low filtration efficiency.** In the manufacture of paint products, a large amount of wastewater is generated from cleaning of reactors and mixing basins. The wastewater contains a wide variety of substances, such as: organic and inorganic pigments, latex, solvents and emulsifying agents. The treatment of latex-paint wastewater by ultrafiltration can serve not only for pollution control but also for latex recovery. One of the benefits of treating water-based paint effluent by ultrafiltration over other processes such as electrochemical oxidation or Fenton oxidation is the potential to reclaim the solid in the effluent as well as to reuse the filtrate as process or cleaning water. However, membrane fouling causes a significant increase in the hydraulic resistance, manifested as a permeate flux decline or a transmembrane pressure increase. The energy consumption in the filtration process thus increases. Membrane fouling also increases the complexity of membrane filtration operation since the system has to be halted frequently to restore the filtrate flux by back-washing. Over a long period of operation, membrane fouling might not be totally reversible by back-washing. In order to regain the membrane efficiency, chemical cleaning is often used. This results in an increased operational cost. In addition, chemical cleaning reduces the membrane lifetime. These make UF less economically feasible for some applications. Therefore, a thorough understanding of this phenomenon and the development of novel techniques to reduce or eliminate membrane fouling are of important.************

超滤(UF)是一种广泛应用的膜分离过程，如：水/废水处理、反渗透水的前处理、食品、化学和生化工业中的分离。随着低压膜的发展，包括超滤在内的膜应用近年来呈指数级增长。然而，超滤应用中的一个主要挑战是料液中的溶质对膜的污染。膜污染会导致滤液通量随时间减少，从而降低过滤效率。**在涂料产品制造过程中，反应器和混合池的清洗会产生大量废水。废水中含有多种物质，如：有机和无机颜料、乳胶、溶剂和乳化剂。采用超滤技术处理乳胶漆废水，既可用于污染治理，又可用于乳胶回收。与电化学氧化或芬顿氧化等其他工艺相比，超滤处理水性涂料废水的好处之一是可以回收废水中的固体，并将滤液作为工艺或清洁水重复使用。然而，膜污染会导致水力阻力的显著增加，表现为渗透通量下降或跨膜压力增加。因此，过滤过程中的能耗增加。膜污染也增加了膜过滤操作的复杂性，因为系统必须频繁停机以通过反冲洗恢复滤液通量。在长时间的运行中，膜污染可能不能通过反冲洗完全逆转。为了恢复膜的效率，经常使用化学清洗。这导致了运营成本的增加。此外，化学清洗会降低膜的使用寿命。这使得UF在某些应用中在经济上不太可行。因此，彻底了解这一现象并开发新的技术来减少或消除膜污染是很重要的。