Advances in Microalgal Technology for Aquaculture Wastewater Treatment

Abstract

With the rapid expansion of the global aquaculture industry, the treatment of aquaculture wastewater containing nitrogen, phosphorus, antibiotics and other pollutants has become a critical factor restricting the industry’s sustainable development. Physical, chemical and biological treatment methods are currently the mainstream technical routes for aquaculture wastewater treatment, yet each has inherent limitations such as high costs, secondary pollution and poor adaptability to complex water quality. As a green biological treatment technology, microalgal treatment has attracted extensive research attention due to its advantages of low operational cost, high pollutant removal efficiency and no secondary pollution. This paper systematically elaborates on the core mechanisms of microalgae in aquaculture wastewater treatment, including the targeted assimilation and removal of nitrogen and phosphorus through photosynthesis and metabolic regulation, the synergistic degradation of complex pollutants by microalgae-bacteria symbiotic systems, and the regulatory effects of key environmental and process factors on treatment efficiency. It further summarizes the construction of microalgal technology systems for aquaculture wastewater treatment, involving the screening and directional optimization of core algal strains, the comparative analysis of mainstream treatment technologies, and the innovation of microalgae-based coupling technologies. Additionally, the paper identifies the current technical and economic bottlenecks faced by the practical application of microalgal treatment technology, such as poor environmental adaptability, unstable system operation, high initial investment and immature biomass resource utilization. Finally, the future development directions are proposed, including the precise optimization of microalgal strains and process parameters, the high-value resource utilization of microalgal biomass, and the integration of synthetic biology, artificial intelligence and other cutting-edge technologies to promote the development of microalgal treatment systems towards high efficiency, intelligence and sustainability. This study provides a comprehensive theoretical basis and technical reference for the green governance and resource utilization of aquaculture tailwater.