Fate of extracellular antibiotic resistant genes in wastewater treatment plants: Characteristics, persistence, transformation, removal and potential risk
Xinyi Li, Lin Lin, Qimeng Liu, Litao Wei, Ling Li, Junqi Liao, Haining Huang
Abstract
Wastewater treatment plants (WWTPs) are widely recognized as critical reservoirs for antibiotic resistance genes (ARGs). While extensive research has focused on the distribution and behavior of total ARGs and intracellular ARGs (iARGs) during wastewater treatment processes , extracellular ARGs (eARGs) have received considerably less attention. This review provides a comprehensive analysis of the fate and transformation of eARGs throughout the wastewater treatment process, from influent to effluent. We first examine the abundance, diversity, and microbial origins of eARGs from various sources. Subsequently, we systematically evaluate the impacts and underlying mechanisms of diverse wastewater contaminants – including microplastics, nanomaterials , disinfectants and their byproducts, as well as pharmaceuticals and personal care products – on the persistence and transformation of eARGs. Furthermore, we assess the removal efficiencies of current wastewater and sludge treatment processes for eARGs, and identify high-risk eARGs that persist in treated effluents. This review highlights the remarkable persistence and dynamic nature of eARGs, which prove challenging to completely eliminate through conventional treatment methods, underscoring the urgent need for innovative approaches to mitigate their potential environmental and public health risks.