Research Progress on the Configurations and Performance of Reducing Pollution and Carbon Emissions by Bacterial–Algal Reactor

Currently, the water ecological environment is severely polluted and traditional bioreactors have issues with high energy consumption and greenhouse gas emissions. However, a promising solution is the bacterial–algal reactor, which is a green bioreactor that can simultaneously treat sewage and fix CO 2 . The main configurations of bacterial–algal reactors, including several types, activated sludge, biofilm, batch biofilm–sludge reactor coupled with activated sludge method, and bacterial–algal open reactor, have been reviewed. The performance of these reactors in reducing pollutants and carbon emissions during wastewater treatment has been investigated. Additionally, the technical advantages of coupling a bacterial–algal symbiosis system with a conventional bioreactor have been analyzed. The interaction mechanism of the bacterial–algal system in various reactors has also been elaborated. The bacterial–algal reactor improves pollutant removal efficiency through assimilation and absorption of pollutants by microalgae, and reduces aeration by releasing oxygen through photosynthesis of microalgae. Finally, the existing problems in the practical application of bacterial–algal reactors have been summarized, and future research directions have been suggested, providing theoretical support for the future application of bacterial–algal reactors and directions for optimal design and development of bacterial–algal symbiotic reactors.