Harnessing biofilm-mediated bioremediation for sustainable wastewater reuse: From mechanisms to policy integration

The necessity for secure wastewater recycling is escalating due to worldwide water shortages, putting the effectiveness of traditional treatment techniques to the test against contaminants of emerging concern (CECs). Biofilm-mediated bioremediation (BMB) utilizes microbial communities encapsulated within an extracellular polymeric substance matrix to enhance pollutant removal through mechanisms of biosorption and biomineralization. This review systematically examines the foundations of BMB, including biofilm formation, microbial diversity, and reactor configurations (e.g., MBBR, MBR), highlighting their effectiveness in eliminating organics, heavy metals, and pathogens. This study explores advanced hybrid systems, like photocatalytic-MBBR, which improve the removal of persistent pollutants and help reduce risks such as the spread of antibiotic resistance genes (ARGs). However, obstacles in sustained stability, ARG propagation, and scalable economic efficiency persist as paramount to the technology's implementation. Uniquely, this work bridges the gap between fundamental science and practical implementation by evaluating how BMB aligns with circular economy principles and United Nations Sustainable Development Goals (SDGs), thereby providing a mechanistic-to-policy roadmap to guide the scaling of biofilm-based solutions for sustainable wastewater management.