Comparative Evaluation of QQ Media Materials for MBR Applications: An Environmental Footprint Approach in Urban Wastewater Treatment Plants

Urban wastewater treatment plants face increasing challenges in mitigating environmental impacts while achieving high treatment efficiency. This study explores the optimization of quorum-quenching (QQ) media materials for scalable membrane bioreactor (MBR) applications, focusing on their potential to reduce operational footprints and enhance sustainability. Six immobilization media were evaluated—sodium alginate (SA), polyvinyl alcohol (PVA) beads (P), magnetic beads (M), chitosan magnetic beads (CM), polymer-coated beads (PS), and flat media (SAP)—using a multi-criteria decision analysis (MCDA) framework. Key parameters, including porosity, mechanical strength, quorum-quenching activity, and durability in sludge, were quantitatively weighted according to their operational significance. SA demonstrated the most balanced performance, exhibiting superior durability and cost-effectiveness, whereas SAP showed potential in applications prioritizing high porosity and enhanced QQ activity. The incorporation of QQ media led to a significant reduction in membrane fouling, chemical consumption, and energy consumption in pilot-scale MBR systems. Ecological footprint assessment revealed a 15% reduction in indirect blue water footprints and a 20% decrease in Scope 2 carbon emissions, attributable to reduced operational energy demands. These findings highlight the efficacy of QQ media in improving MBR performance and advancing system-level sustainability. Overall, this study highlights the critical importance of material engineering and ecological footprint integration in the development of next-generation urban wastewater treatment technologies.