Current progress in semi-batch reverse osmosis for brackish water desalination

Semi-batch reverse osmosis (SBRO) is an innovative membrane process renowned for its compact system and high recovery in desalination and water reuse. While academic research provides valuable insights, aligning it with real-world implementation is crucial. The study aims to understand the current progress in SBRO for brackish water desalination by identifying performance disparities between academic research and practical applications, evaluating practical performances under realistic parameters, and proposing future research directions. Through gathering and comparing data from SBRO research and practices, performance disparities between theoretical projections and real-world applications were identified. The analysis revealed that specific energy consumption (SEC) in academic research had been underestimated by applying impractical pump efficiencies, and permeate quality was often neglected. To assess the practical SEC and permeate quality of SBRO, engineering design calculations were performed with realistic parameters. Based on the evaluation, the importance of maintaining suitable recovery and incorporating a permeate tank was emphasized to avoid a significant increase in SEC and to stabilize water quality, respectively. Given the challenges of the SBRO system, the discussion further outlined research directions addressing issues in energy efficiency, permeate quality, membrane fouling/scaling, and practical design/operation. It recommended considering these practical aspects for the broader applications of SBRO. [Display omitted] •Current progress in SBRO was identified with theoretical and industrial perspectives.•Process modeling with engineering designs was applied to evaluate SBRO performance.•Data from SBRO research and practices were collected and critically compared.•SEC and permeate quality of SBRO were estimated by considering practical conditions.•Future research directions were outlined for the expansion of SBRO technology.