Fouling and fouling mitigation in batch reverse osmosis: review and outlook

In recent years, many advances have been made in reverse osmosis (RO) technology, and in understanding the fouling and scaling phenomena that limit its performance and durability. One of these advances, batch RO, is an unsteady process that has several flow characteristics that are absent in standard reverse osmosis processes. These include osmotic backwashing, feed flow reversal, salinity cycling and water hammer/pulse flow. This paper has three aims. First, it introduces batch RO and reviews recent progress in this area. Second, it reviews the fouling phenomena experienced in RO, covering the fouling mechanisms, detection methods currently in use, and mitigation methods already used in conventional RO. Lastly, it reviews specific flow characteristics experienced in batch reverse osmosis and it discusses the effects that they may have on the fouling. The paper concludes by recommending research activities to advance further batch RO technology for improved mitigation of fouling.