Development of novel cleaning techniques for nanofiltration (NF) membranes

项目背景：清洁的水是生命的基础：联合国最近报告称，到2050年，对水的需求预计将增加55%。然而，由于淡水资源短缺和质量下降，预计到2025年，生活在缺水条件下的全球人口比例将从三分之一上升到三分之二。这就产生了一个紧急的、未得到满足的优先事项--确保为每个人提供可靠和可持续的清洁水。为了实现这一目标，改进和开发新的水处理技术势在必行，该项目朝着涉及膜过滤的解决方案迈出了重要的一步。纳滤膜过程越来越受欢迎，因为它们从许多可用的水源提供高质量的水，包括饮用水，就像苏格兰的情况一样。高压进料水通过膜过滤，产生渗透液，即清洁的水，同时污染物保留在进料端。然而，众所周知，由于膜表面污染物的积累，膜会被污染，导致渗透水的质量和流量危险地降低，增加了操作和能源成本，并缩短了膜的寿命。氯化等化学清洗方法可用于防止膜污染，但效率低且需要工艺停机。它们还可以改变膜的性质，最终缩短其寿命。本项目将评估去除纳滤膜污染的新清洗技术，并将它们与目前采用的技术进行比较。这些措施将包括定期向膜的输入进料流中引入高盐度突发--高盐度脉冲(HSP)。热休克蛋白的插入在膜的进料侧和渗透侧之间产生了高渗透压差。结果，水通过膜的渗透方向暂时反转，从渗透侧流向进料侧。因此，膜被反冲洗，污染被有效地从表面去除。这种清洗技术将以更低的成本保持水的产量和质量，并延长膜的使用寿命，对使用纳滤膜的行业产生立竿见影的效果。这些行业包括水、废水、水产养殖和食品饮料行业。关键研究问题：-HSP是否适用于所有类型的氮肥配置，即管状和螺旋伤口？-HSP的最佳条件是什么，这些条件如何取决于膜类型和污染特性？-HSP清洗和其他开发的清洗制度与当前应用的清洗制度相比如何？EPSRC职权范围和EPSRC优先领域：由于目前在水管理和供应方面存在挑战，联合国可持续发展目标的目标6侧重于确保为每个人提供可靠和可持续的清洁水。EPSRC最近将“为所有人提供水的可持续工程解决方案”确定为工程领域的重大挑战，而工程主题中的水工程研究领域是一个优先增长领域，该项目非常适合这一领域。水对英国来说是一个重要的经济领域，EPSRC在这个主题上有相当多的资助研究。目前的水工程投资组合包括37笔赠款，总价值4700万GB。

Project Background: Clean water is the foundation of life: the UN recently reported an expected increase in demand for water of 55% by 2050. The percentage of the global population living under water stressed conditions is, however, expected to rise from 1/3 to 2/3 by 2025, due to shortage and reduced quality of freshwater resources. This creates an urgent, unmet priority - ensuring the reliable and sustainable provision of clean water for everyone. To meet this target, improvement and development of new water treatment technologies are imperative, and this project takes an important step toward a solution involving membrane filtration.Nanofiltration membrane processes are increasingly popular as they supply high quality water, including drinking water, from many available water sources, as is the case in Scotland. A high pressure feed water is filtered through the membrane, producing permeate, i.e. clean water, whilst contaminants are retained on the feed side. Membranes are however known to foul due to an accumulation of contaminants on the membrane surface, leading to dangerously reduced quality and flow of permeated water, increased operational and energy costs and membrane life reduction. Chemical cleaning regimes, such as chlorination, are used to combat membrane fouling, but are inefficient and require process downtime. They can also modify the properties of the membrane, ultimately reducing its life. This project will assess novel cleaning techniques to remove fouling from NF membranes and compare them with current adopted ones. These will include the regular introduction of a burst of high salinity - a High Salinity Pulse (HSP) - into the input feed flow of the membrane. The HSP insertion creates a high osmotic pressure difference between the feed and permeate sides of the membrane. As a result, the direction of water permeation through the membrane temporarily reverses, flowing from the permeate side to the feed side. Consequently, the membrane is backwashed and fouling is efficiently removed from the surface. This cleaning technique will maintain water production quantity and quality at reduced costs and extend the usable lifespan of a membrane, having an immediate transformative effect on industries where NF membranes are used. These include the water, wastewater, aquaculture and food & drink industries. Key Research Questions:- Is HSP applicable to all types of NF configurations, i.e. tubular and spiral wound?- What are the optimal conditions for HSP and how do these depend on membrane type and fouling characteristics?- How does HSP cleaning and other developed cleaning regimes compare with current applied cleaning regimes?EPSRC remit and EPSRC priority area: Due to the current challenges presented in water management and provision, Goal 6 of the UN Sustainable Development Goals focuses in ensuring the reliable and sustainable provision of clean water for everyone. EPSRC has recently identified "Sustainable engineering solutions to provide water for all" as an Engineering Grand Challenge and Water Engineering research area in the Engineering theme is a priority growth area, in which this project fits perfectly. Water is an economically important area to the UK, and EPSRC has a considerable body of funded research in this theme. The current portfolio for Water Engineering comprises 37 grants of total value £47M.