Biodegradation of pharmaceutical contaminants in wastewater using microbial consortia: Mechanisms, applications, and challenges.

Pharmaceuticals, including non-steroidal anti-inflammatory drugs and antibiotics, have been increasingly detected in wastewater and pose substantial ecological and public health concerns due to their persistence and bioactivity. Conventional treatment processes are often insufficient for their complete removal, highlighting the need for advanced bioremediation strategies. This review critically examines the mechanisms, applications, and challenges of microbial consortia for pharmaceutical biodegradation. It emphasizes their synergistic metabolic pathways, such as cross-feeding, co-metabolism, and enzymatic cascades, that enable efficient degradation of complex contaminants. Recent advancements, such as membrane bioreactors, bioaugmentation with genetically engineered consortia, and integrated systems coupling microbial processes with advanced oxidation processes, are reviewed for their potential to enhance treatment efficacy, scalability, and sustainability. Comparative analysis underscores microbial consortia's superiority over single-strain systems and adsorption techniques in treating complex contaminant mixtures, achieving up to 100 % removal efficiency for specific compounds. Persistent challenges include microbial community instability, the toxicity of transformation products, and regulatory constraints related to genetically modified organisms. Strategic solutions are proposed, such as pilot-scale implementation of tailored consortia, Internet of things (IoT)-enabled real-time monitoring, and circular economy approaches for resource recovery. By addressing these challenges, microbial consortia-based biodegradation emerges as a transformative solution for pharmaceutical wastewater treatment, aligning with global sustainability goals. This review provides actionable insights for optimizing bioremediation frameworks, informing policy, and advancing research in environmental microbiology and wastewater engineering.