An Overview Towards Mitigating the Dissemination of Antibiotic Resistance Genes Through Implementing Advanced Oxidation Processes (AOPs) for Wastewater Treatment

Antibiotic resistance genes (ARGs) as emerging contaminants (ECs) of concern, has raised alarming health concerns globally across geographical locations. Municipal wastewater treatment plants (WWTPs) have emerged as a significant cause for these ARGs and associated antibiotic-resistant bacteria (ARBs). WWTPs receives an influx of antibiotics from a plethora of anthropogenic sources ranging from municipal wastes, livestock wastes, hospitals, and pharmaceutical manufacturing industry. Conventional treatment methods have shown limited capabilities in effectively removing these emerging contaminants ranging from antibiotic residues, active pharmaceutical ingredients (APIs) and ARGs. It puts selection pressure on the proliferating microbes to develop antimicrobial resistance (AMR) and aid in their distribution through the system into the environment. Various disinfection methods have been implemented to remove ARGs in WWTPs such as chlorination and UV to eliminate microbial loads in wastewater, but ARGs have been shown to be persistent and survive these conventional treatments. In recent times, advanced oxidation processes (e.g. Ozone, UV/H2O2, Fenton) have gained attention due to their increased efficacies in ARG abatement, albeit showing variable results. However, adequate data on the effect of influencing factors on the occurrence, dissemination, and fate of ARGs is lacking in the literature. Therefore, the key objective of this review chapter is to provide a comprehensive overview of the fate of ARGs in WWTP systems and discuss the influence of operational factors and the efficacy of treatment technologies regarding its mitigating potential. In addition, current challenges pertaining to AOPs are discussed, and key knowledge gaps are suggested for future research which could aid in better understanding the impact of influencing factors on the ARGs fate during implementation of various AOPs.