Today, wastewater management remains one of the most pressing environmental challenges due to its contamination of numerous natural water bodies. Advancements in the integration of physicochemical and biotechnological approaches have significantly improved sewage treatment processes. However, despite these developments, the role of microbial communities within biofilms in enhancing water purification remains unclear. This research seeks to address critical questions: Which microorganisms are most active in contributing to wastewater treatment, particularly in biofilm waste treatment (i.e., rotating disk reactors)? What factors influence biofilm formation in wastewater treatment plants? How do microbial communities drive the removal of carbon and nitrogen in these systems? The primary aim of this study is to investigate the composition of microbial communities across different wastewater treatment techniques, identifying the most active microorganisms involved in carbon and nitrogen removal. Additionally, the research will involve designing experiments under simulated conditions using a lab-scale bioreactor to promote biofilm formation and assess the efficiency of carbon and nitrogen removal. These findings could open new avenues for optimizing wastewater treatment processes under real-world conditions.