Forward osmosis (FO) is a membrane-based process that explores the osmotic pressure difference between a feed solution and a draw solution to induce water transport across a semipermeable membrane. Water transport results in the dilution of the draw solution which is reconcentrated using a recovery process. Different from the reverse osmosis process, FO requires lower grade energy and has other advantages, namely, a wide range of applications and a reversible fouling phenomenon of FO membranes. In spite of its many advantages, the FO process is facing drawbacks among which the lack of high-performance membranes. Today, the development of improved FO membranes, capable of achieving a high water flux with a very low reverse salt flux is one of the biggest concerns of membrane scientists. This paper summarizes the basic principle of the FO process, some modern applications, and the main challenges related to membranes. It also describes the progresses in FO membrane development, particularly regarding the membrane manufacturing techniques, commercially available, and R&D membranes.

正向渗透（FO）是一种基于膜的工艺，可探索进料溶液和汲取溶液之间的渗透压差，以诱导水通过半透膜的传输。水的输送导致汲取溶液的稀释，然后使用回收工艺对其进行浓缩。与反渗透工艺不同，FO所需的能量较低，并且具有其他优势，即FO膜的应用范围广且可逆结垢现象。尽管FO方法具有许多优点，但其仍面临着缺点，其中缺少高性能的膜。如今，开发能够实现高水通量和非常低的反向盐通量的改进型FO膜是膜科学家最关注的问题之一。本文总结了FO过程的基本原理，一些现代应用，以及与膜相关的主要挑战。它还描述了FO膜开发的进展，特别是在膜制造技术，可商购获得的R＆D膜方面。