Constructed Wetlands as Nature-Based Solutions for the Removal of Antibiotics: Performance, Microbial Response, and Emergence of Antimicrobial Resistance (AMR)

Abstract

Antibiotics and antibiotic resistance genes (ARGs) have been regarded as emerging pollutants and pose significant threats to the aquatic environment and to human health. This study aimed to investigate the removal of nutrients, antibiotics, and the emergency of ARGs in domestic sewage by means of constructed wetlands (CWs) filled with an electroconductive media, i.e., coke. In this study, the antibiotics removal efficiencies ranged from 13% to 100%, which were significantly higher in the system filled with coke compared with the CWs filled with common quartz sand (7%~100%). Moreover, the presence of wetland plants could also significantly improve the removal of nutrients and tetracyclines. The results also demonstrated the importance of substrate selection and wetland plants in CWs on the alternation of microbial communities and structures, where the electroconductive media showed a promising effect on increasing the removal of antibiotics in CWs. In terms of the emergency of ARGs, the CWs filled with coke retained the most ARGs (10,690 copies/g) compare with the control groups (8576–7934 copies/g) in the substrate. As the accumulated ARGs could be released back to the watercourse due to the environmental/operation condition changes, the application of such an advanced substrate in CWs may pose a more significant potential threat to the environment. With these results, this study provided new insight into selection of the substrates and plants for wastewater treatment to achieve a sustainable and secure water future.

Assessment of novel hybrid treatment wetlands as nature‐based solutions for pharmaceutical industry wastewater treatment

“…It should be noted that the degradation of pharmaceuticals in TWs relies primarily on microbial‐mediated biodegradation processes (Ilyas & van Hullebusch, 2020). Thus, there is a high potential for antimicrobial resistance (AMR) to be generated and present in the discharged effluent (Bai et al, 2022). AMR monitoring was not included in the current study.…”

“…The results demonstrate that the increased concentration of NO 3 À -N in the TFTW effluent primarily resulted from the transformation of NH 4 + -N via the nitrification process in the welloxygenized TFTW bed. Meanwhile, the removal of TN in TFTW (Figure 3c,f) was mainly attributable to other forms of nitrogen, such as nitrogen-containing organic compounds like proteins, amino acids, and urea in pharmaceutical wastewater (Wang et al, 2022). The subsequent stage of HSSF TW with the anoxic condition was found to be more conducive for the denitrification process, leading to significant removal of NO 3 À -N (Figure 3e) and contributing to the reduction of TN (Figure 3c).…”

“…River gravels/sands are the most commonly used substrates in TWs because of their low cost and widespread availability (Yazdania & Golestanib, 2019). However, advanced natural and artificial materials with high surface area and pore volume, such as zeolite, have been used as wetland substrates to increase pollutants' retention time in the system through adsorption processes (Bai et al, 2022). Moreover, it is reported that zeolite materials have significant adsorption capabilities towards high pharmaceutical compound removal (Al-Mashaqbeh et al, 2021).…”