Coir based biofiltration system for enhanced removal of water pollutants

This study examines the use of layer by layer (LbL) coated coir (CC) systems to eliminate bacterial pathogens and emerging contaminants from water. Bacterial and chemical contaminants found in river water pose risks to human health and aquatic ecosystems. The study initially compared the effectiveness of CC to uncoated coir (UC) treatment in removing bacterial pathogens. CC treatment demonstrated superior removal efficacy compared to UC treatment. For samples with a bacterial concentration of 3.6×103 CFU/mL, CC treatment achieved a removal rate exceeding 90% and viability losses of over 60% for E. coli and over 90% for S. aureus. As the number of bilayers increased, the regrowth potential of bacteria decreased, leading to mortality rates of ∼ 97% for S. aureus and 65% for E. coli respectively. Furthermore, the superiority of CC over UC in removing emerging contaminants were demonstrated. CC attained removal efficiencies of over 99% for isoniazid, 95.08% for lidocaine, 95.21% for mefenamic acid, and 87.73% for caffeine. The reproducibility of the CC system was tested and showed stable removal efficiency over multiple cycles. These findings highlight the potential of CC systems as effective eco-friendly alternatives for water purification to remove bacterial pathogens and emerging contaminants.