Pyrite from acid mine drainage promotes the removal of antibiotic resistance genes and mobile genetic elements in karst watershed with abundant calcium carbonate

More information is needed to fully comprehend how acid mine drainage (AMD) affects the phototransformation of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in karst water and sewage -irrigated farmland soil with abundant carbonate rocks (CaCO 3 ) due to increasing pollution of AMD formed from pyrite (FeS 2 ). The results showed FeS 2 accelerated the inactivation of ARB with an inactivation of 8.7 log. Notably, extracellular and intracellular ARGs and mobile genetic elements (MGEs) also experienced rapid degradation. Additionally, the pH of the solution buffered by CaCO 3 significantly influenced the photo -inactivation of ARB. The Fe 2 + in neutral solution was present in Fe(II) coordination with strong reducing potential and played a crucial role in generating center dot OH (7.0 mu M), which caused severe damage to ARB, ARGs, and MGEs. The center dot OH induced by photo -Fenton of FeS 2 posed pressure to ARB, promoting oxidative stress response and increasing generation of reactive oxygen species (ROS), ultimately damaging cell membranes, proteins and DNA. Moreover, FeS 2 contributed to a decrease in MIC of ARB from 24 mg/L to 4 mg/L. These findings highlight the importance of AMD in influencing karst water and sewage -irrigated farmland soil ecosystems. They are also critical in advancing the utilization of FeS 2 to inactivate pathogenic bacteria.