Biofilm Control in Wastewater Treatment: A Review Regarding the Application of Quorum Sensing and Quenching Processes and Future Perspectives

Wastewater treatment (WWT) is among the main challenges in environmental engineering. However, conventional wastewater treatment methods are limited by several aspects, mostly related to efficiency, excessive energy requirements, and surplus sludge production. Thus, the alternative use of biofilms (instead of suspended biomass/activated sludge systems) has garnered particular interest, especially due to their ability to sustain high microbial activity and withstand extreme conditions. This review aims to provide an interdisciplinary and comprehensive approach to understanding the main interactions occurring in biofilms, emphasizing, specifically, the quorum sensing (QS) and the quorum quenching (QQ) mechanisms, as well as to address their relative applications in controlling biofouling problems, e.g., during the operation of membrane bioreactors (MBRs). The review summarizes and analyzes the latest developments, highlights the relevant research gaps in the literature, and links microbiological knowledge with related technological applications.