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

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.