Currently over 845 million people are believed to be living under severe water scarcity, and an estimated 2.8 billion people across the globe are projected to come under serious water scarcity by the year 2025, according to a United Nations (UN) report. Seawater desalination has gained more traction as the solution with the most potential for increasing global freshwater supplies amongst other solutions. However, the economic and energy costs associated with the major desalination technologies are considered intrinsically prohibitive largely due to their humongous energy requirements alongside the requirements of complex equipment and their maintenance in most cases. Whilst forward osmosis (FO) is being touted as a potentially more energy efficient and cost-effective alternative desalination technique, its efficiency is challenged by draw solutes and the draw solutes recovery step in FO applications alongside other challenges. This paper looks at the present situation of global water scarcity, and a brief leap into the major desalination technologies employed. A closer look at the key drivers of FO as a seawater desalination technique in their individual domain and its outlook as an technology are further highlighted.

中文翻译：

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海水淡化：正向渗透技术的回顾，其挑战和未来前景

据联合国（UN）报告，目前据信超过8.45亿人生活在严重缺水之下，预计到2025年，全球估计有28亿人将面临严重缺水。海水淡化作为解决方案，除其他解决方案外，最有潜力增加全球淡水供应，因此受到了越来越多的关注。但是，与主要海水淡化技术相关的经济和能源成本在本质上被认为是过高的，这主要是因为它们的能源需求巨大，而且在大多数情况下还需要复杂的设备及其维护。尽管正向渗透（FO）被吹捧为一种潜在的更节能，更具成本效益的替代淡化技术，FO应用中的提取溶质和提取溶质回收步骤挑战了其效率，同时还面临其他挑战。本文着眼于全球水资源短缺的现状，并简要介绍了所采用的主要海水淡化技术。进一步重点介绍了FO作为其各自领域中的海水淡化技术的主要驱动力及其技术前景。