Outflow risks of antibiotic-resistant bacteria in stormwater bioretention cells: understanding roles of adsorption and transmission

Abstract In this study, lab-scale bioretention cells were designed for the investigation of antibiotic-resistant bacteria (ARB) outflow profiles at different depths, effects adsorption and transmission, as well modelling evaluation ARB risks using common decay models (e.g., first-order models). was first found in upper layers (after 100 days operation) with lowest transmission frequencies antibiotic resistance. Although onto substrate its surface biofilms effective maximum amount adsorbed (Qmax) reaching 108 CFU/g 107 biofilms, detected bottom outlets after over 4 months operation, reflecting that there still a risk resistance through treatment cells. both middle could be described by third-order polynomial equations correlation coefficients 0.9067 (p = 0.0002) 0.9780 < 0.0001), respectively, where positive negative relationships between inflow ARB, conforming combined action mechanisms blocking adsorption) promoting (like transmission). These suggested two potential controlling approaches from stormwater