A comprehensive review of pressure and osmosis driven membrane processes: Processes, characteristics and materials

With increasing global concerns over freshwater scarcity and increasing pollution of water resources, membrane separation processes have emerged as a vital technology for sustainable, efficient, and cost-effective solutions for water purification, wastewater treatment, and desalination. The two large subclasses of membrane-based separation surveyed in this review are pressure-induced membrane separation and osmotic separation. Among them, reverse osmosis (RO) is a pressure-driven process in which hydraulic pressure is used during separation, whereas both forward osmosis (FO) and pressure-retarded osmosis (PRO) are osmotically powered processes that utilize osmotic pressure differences. These processes have been applied to many important applications, such as potable water supply and industrial wastewater reclamation. In this review, the basic principles of these processes and their performance, progress, merits, and demerits are presented. It compares the key performance parameters of various technologies in terms of flux, selectivity, fouling resistance, and energy consumption to establish the suitability of each technology for specific applications. Furthermore, recent developments related to membrane materials are discussed, focusing on newly developed polymeric and composite membranes with improved permeability and selectivity to ensure better fouling management. Emphasis has been placed on recent nanomaterials because of their high potential for enhancing membrane efficiency. Although there are noticeable advances in the field, much more effort has to be undertaken to overcome the continuous challenges in the areas of fouling, energy consumption, and stability of the materials involved, which is a key issue for practical realization at the industrial scale worldwide. This review provides a systematic overview of membrane-based processes and their role in meeting the growing demand for clean water, offering valuable insights for the future development of energy-efficient and robust membranes. •Performance, advances, advantages and limitations of desalination process are studied•Permeability, selectivity and fouling of polymeric and composite membrane are evaluated.•Nanomaterials (NMs), their properties and desalination applications were discussed.•Significance of NMs in modifying membrane characteristics are highlighted.