A review: Improving aquaculture rearing water quality by removal of nutrients using microalgae, challenges and future prospects

Intensive aquaculture practices often result in nutrient accumulation and progressive eutrophication, affecting both the cultured species and adjacent water bodies. This has prompted interest in adopting more efficient and cost-effective nutrient removal techniques as alternatives to conventional methods. Consequently, an innovative phycoremediation technique is employed to remove the excess nutrients from wastewater. Microalgae are particularly skilled at utilizing the nutrients in rearing water to their advantage. This review summarizes current knowledge about the characteristics of microalgae, their use for nutrient removal and their interactions with bacteria. The use of microalgae-bacteria consortia for improving the water quality has gained popularity because the combined effects of these organisms offer greater environmental stability and adaptability than microalgae alone, thereby enhancing nutrient removal effectiveness. This study aims to enhance understanding of the advantages and constraints of employing microalgae to improve rearing water quality. This review also provides an in-depth examination of the key factors, and limitations of microalgae-based nutrient removal from aquaculture waste. It also analyzes the latest literature on nutrient removal from aquaculture effluent using microalgalbacterial technology, along with its potential for future applications.