Development of novel cleaning techniques for nanofiltration (NF) membranes

项目背景：清洁的水是生命的基础：联合国最近报道，预计到2050年，对水的需求将增加55%。然而，由于淡水资源短缺和质量下降，预计到2025年，生活在水资源紧张条件下的全球人口比例将从1/3上升到2/3。这创造了一个紧迫的、尚未实现的优先事项——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，而该项目在膜过滤解决方案方面迈出了重要的一步。纳滤膜工艺越来越受欢迎，因为它们从许多可用的水源中提供高质量的水，包括饮用水，就像苏格兰的情况一样。高压给水通过膜过滤，产生渗透水，即净水，同时污染物保留在给水侧。然而，众所周知，由于污染物在膜表面的积累，膜会发生污染，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。化学清洗机制，如氯化，用于对抗膜污染，但效率低下，需要过程停机。它们还可以改变膜的特性，最终缩短膜的寿命。本项目将评估去除纳滤膜污垢的新清洁技术，并将其与目前采用的清洁技术进行比较。这将包括定期向膜的输入进料流中引入高盐度脉冲（HSP）。HSP的插入在膜的进料侧和渗透侧之间产生高渗透压差。因此，水通过膜的渗透方向暂时逆转，从渗透侧流向进料侧。因此，膜被反冲洗，污垢被有效地从表面去除。这种清洁技术将以较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直接的变革性影响。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：-热热防护是否适用于所有类型的NF结构，即管状和螺旋形绕线？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？-与目前应用的清洁方式相比，热热加热清洁和其他已开发的清洁方式如何？EPSRC的职责和优先领域：由于目前在水管理和供应方面面临的挑战，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。水对英国来说是一个重要的经济领域，EPSRC在这方面有相当多的资助研究。水工程目前的投资组合包括37笔赠款，总价值4700万英镑。

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.