Microalgal–Bacteria Biofilm in Wastewater Treatment: Advantages, Principles, and Establishment

The attached microalgal–bacterial consortium (microalgae–bacteria biofilm, MBBF) has been increasingly recognized in wastewater treatment for its superior pollutant removal efficiency, resilience to toxic substances, and improved harvesting performance. This review initially discusses the advantages of MBBFs compared to activated sludge and suspended microalgal–bacterial consortia. These advantages stem from the coexistence of pollutant removal pathways for the bacteria and microalgae in MBBFs, as well as the synergistic interactions between the microalgae and bacteria that enhance pollutant removal and resilience capabilities. Subsequently, the establishment of the MBBF system is emphasized, covering the establishment process, influencing factors of MBBF formation, and the utilization of photobioreactors. Lastly, the challenges associated with implementing MBBFs in wastewater treatment are deliberated. This study aims to present a detailed and comprehensive overview of the application of MBBFs for wastewater treatment and biomass production.