Biofiltration of Emerging Contaminants as a Sustainable Pest Management Strategy and Its Impact on Corbicula fluminea.

Background/Objectives: Water scarcity is driving the development of strategies for treating municipal wastewater (MW) to enable its safe reuse. Nonetheless, MW contains contaminants of emerging concern (CECs), such as pharmaceuticals and antimicrobial-resistant (AMR) bacteria, which require innovative treatment technologies. In this context, Corbicula fluminea, an invasive freshwater clam, presents a high biofiltration capacity, and its environmental impact could be mitigated by assigning it a beneficial role in wastewater treatment. Methods: The ability of C. fluminea to remove chemical and biological CECs from real MW secondary-treated effluents was assessed. The effects of real wastewater on the clams' microbiome and on colony-forming unit (CFU) counts in their soft tissues were also assessed. Results: Under real conditions, the clams achieved over 73% removal for 3 chemical CECs after 24 h, with an average removal of approximately 39%. The clams showed recovery of both CFU counts and microbial community composition, dominated by opportunistic and stress-tolerant groups in the presence of pharmaceuticals. The removal of multidrug-resistant bacteria was evaluated; despite real wastewater reducing clearance rates, the clams significantly reduced these bacteria within 24 h. Conclusions: These results demonstrate that C. fluminea can serve as an effective polishing treatment, improving effluent quality, supporting control of this invasive species.