Performance of photobioreactor, constructed wetland and anaerobic membrane bioreactor in treating antibiotic resistant bacteria in the Barapullah drain, New Delhi, India

Abstract

Limitless usage of antibiotics has led antibiotic resistance to be one of the largest threats to world health and development. In this study, the concentrations of Extended spectrum betalactamase Escherichia coli and carbapenem resistant Escherichia Coli was assessed in a major drain in New Delhi, India. The performance of Anaerobic membrane bioreactor, photobioreactor and constructed wetlands in treating ESBL-E.coli and CRE-E.coli was evaluated. The results showed ESBL-E.coli and CRE-E.coli removal efficiencies of 99.82% and 99.69% for AnMBR, 99.62% and 99.86% for PBR and 98.1-99.3% for constructed wetlands respectively. Log10 reduction values of 2.7-3 for AnMBR, 2.8-3.2 for PBR and 1.82.3 for CWs was achieved in this study. Coupling micro-aeration with AnMBR improved the removal efficiency by 36-46%. A quantitative microbial risk assessment showed probability of infection by Enterotoxigenic E.coli (ETEC O55) post treatment to be reduced below 10-18% for AnMBR and PBR and below 20-35% for CWs. Treated effluents accounted for a high reduction in the total DALYs pppy by 63% for PBR, followed by 41.6% for AnMBR and 12.5% for CWS. ESBL-E. coli and CRE-E.coli counts decreased below the monitoring level of 103-105 for unrestricted irrigation and 104-105 for restricted irrigation as declared by WHO. Treated water was not recommended for direct consumption due to higher risk above 10%. This study exhibits the potential of these efficient and sustainable technologies in treating antibiotic resistant bacteria.