Algae-bacteria symbiotic biofilm system for low carbon nitrogen removal from municipal wastewater: A review

The treatment of municipal wastewater has become a significant challenge due to its intricate composition and low carbon-to-nitrogen ratio. In order to meet the discharge standards, a large amount of energy is consumed. In this context, the incorporation of microalgae into the conventional activated sludge process has become a promising strategy for low-carbon denitrification. This study aims to integrate research on algal-bacterial symbiotic systems with biofilm technology to enhance energy-efficient nitrogen removal in municipal wastewater treatment. Through comprehensive analysis, this paper elucidates (1) the developmental dynamics of algal-bacterial symbioses, (2) the process of combining algal-bacterial symbiotic systems with biofilm systems, (3) the fundamentals and operational determinants of algal-bacterial symbiotic membrane systems, and (4) the potential applications in sustainable water treatment. The proposed hybrid system demonstrates significant potential for carbon-neutral wastewater treatment through synergistic pollutant degradation, offering an innovative approach to address critical challenges in environmental sustainability and water resource management.