A review on algal biomass dewatering and recovery of microalgal-based valuable products with different membrane technologies

Efficient microalgae harvesting and dewatering are critical processes for a range of applications, including the production of raw materials, nutritional supplements, pharmaceuticals, sustainable biofuels, and wastewater treatment. The optimization of these processes poses significant challenges due to the need for high efficiency and sustainability while managing costs and energy consumption. This review comprehensively addresses these challenges by focusing on the development and application of various membrane filtration technologies specifically designed for the effective harvesting and dewatering of algal biomass. Membrane filtration has emerged as a predominant method due to its ability to handle large volumes of microalgae with relatively low energy requirements. This review systematically examines the different membrane-based technologies and their effectiveness in recovering valuable components from algal biomass, such as lipids, proteins, and carbohydrates. The discussion begins with an overview of the physical characteristics of microalgae and their cultivation conditions, which are critical for understanding how these factors influence the performance of membrane filtration processes. Key aspects such as the features of algal cells, the presence of algal organic matter, and transparent exopolymer particles are explored in detail. The review also delves into various strategies for improving membrane antifouling properties, which are essential for maintaining the efficiency and longevity of the filtration systems. In addition, the advantages and disadvantages of different membrane techniques are reviewed, highlighting their respective performance in separating microalgae and dewatering. Finally, the review offers insights into future research directions and technological advancements that could further enhance the efficiency and sustainability of microalgae processing. This comprehensive evaluation aims to provide a thorough understanding of current membrane technologies, their applications, and the ongoing developments necessary to overcome existing limitations and improve overall process performance.