Degradation of antibiotic resistance contaminants in wastewater by atmospheric cold plasma: kinetics and mechanisms

Abstract

ABSTRACT This work employed the atmospheric cold plasma technology to efficiently control the antibiotic resistance contaminants in the wastewater effluent. We found that the plasma inactivated the antibiotic-resistant Escherichia coli through multiple damages on the cell membranes and intracellular components (enzymes and DNA). Plasma treatment at an influence of 0.71 kJ/cm2 resulted in a more than 3 log10 CFU/ml reduction (>99.999%) of E. coli in an actual wastewater system. We further estimated the effect of plasma on the ampicillin (blaTEM ) and tetracycline (tet) resistance genes. The results demonstrated that an applied plasma dose of 1.06 kJ/cm2 could significantly (P < .05) eliminate the extracellular (e-) blaTEM and tet genes by 3.26 and 3.14 log10 copies/ml, respectively. Higher plasma intensity was required for the efficient reduction of intracellular (i-)antibiotic resistance genes (ARGs) than extracellular (e-)ARGs due to the shielding effect of the outer envelopes or intracellular components. The inactivation of E. coli and the degradation of e- and i-ARGs can be well described by the Weibull models. The results here provide the evidence for the potential of the plasma technology as a water/wastewater treatment technology.