Microbiological Analysis of Two Deep Constructed Wetlands with Special Emphasis on the Removal of Pathogens and Antibiotic-Resistant Bacteria

• Published in: Water, air, and soil pollution air, and soil pollution, 2021-05, Vol.232 (5), Article 174
• Main Authors: Rampuria, Aakanksha, Gupta, Akhilendra Bhushan, Kulshreshtha, Niha Mohan, Brighu, Urmila
• Format: Article
• Language: English
• Subjects: Analysis; Antibiotic resistance; Antibiotics; Architectural design; Artificial wetlands; Atmospheric Protection/Air Quality Control/Air Pollution; Attenuation; Bacteria; Beta lactamases; Bioreactors; Carbapenemase; Cefoperazone; Climate Change/Climate Change Impacts; Coliforms; Colistin; Constructed wetlands; Disease resistance; Drug resistance; Drug resistance in microorganisms; Earth and Environmental Science; Environment; Environmental monitoring; Faecal coliforms; Fecal coliforms; Hydrogeology; Load distribution; Loading rate; Metabolism; Metagenomics; Microbial activity; Microbiological analysis; Microbiology; Microorganisms; Moving beds; New technology; Organic loading; Pathogenic microorganisms; Pathogens; Piperacillin; Pollutants; Purification; Removal; Sewage; Sewage treatment; Soil Science & Conservation; Substrates; Treated sewage; Wastewater; Wastewater treatment; Water Quality/Water Pollution; Wetlands; β Lactamase
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-021-05121-3

With the global concern on the role of wastewater treatment technologies in manifesting the emergence and dissemination of antibiotic-resistant bacteria (ARB), it has now become imperative to analyze the emerging technologies for handling them. This study assesses the efficiency of two deep constructed wetlands (CWs) receiving partially treated sewage from a residential complex and a hospital designed for the removal of organics and pathogens. These systems were further analyzed for the presence of major ARB to identify the role of CWs in mitigating antibiotic resistance among microbial communities. The bacterial community responsible for metabolic conversions was analyzed by metagenomic sequencing. Finally, the efficiencies of deep CWs were analyzed for the removal of specific bacteria resistant to three antibiotics—piperacillin, colistin (polymixin E), and cefoperazone. The overall removal of extended spectrum beta lactamase producers and carbapenemase producers was also studied. Our results indicate that CWs offer decent BOD and COD removal efficiencies of 74.04–78.71% and 53.85–64.37% respectively. However, a zero-order reaction between loading rate and removal rate was obtained after loading rate of 170 g/m 2 .day indicating the organic loading capacity of the system. Metagenomic analysis revealed the presence of bacteria with diverse metabolic potentials for substrate conversion. Removal of fecal coliforms was high in the CWs, but the most interesting observation was the attenuation in ARB, which was found to be comparable to, or even better, than the reported values from conventional moving bed bioreactor. This observation may be attributed to the high retention times offered by CWs compared to that of conventional systems making them an attractive future alternative for treating domestic as well as hospital sewage for emerging pollutants.