Degradation Of Antibiotic,Resistance Escherichia Coli And Resistance Genes By Discharge Plasma In An Aqueous Solution

Recently,emerging contaminants such as antibiotic,antibiotic resistance bacteria?ARB?and antibiotic resistance genes?ARGs?are becoming a global environmental pollution problem.However,deficiencies of conventional technologies for emerging contaminants degradation are nonnegligible.Therefore,searching a more efficient degradation processes for reducing the risk of emerging contaminants.The main research object of this study is the norfloxacin?NOR?that typical quinolone antibiotic,multi-resistant bacteria resistance E.coli HB101 and its resistance gene the possibility of using cold plasma for degrading NOR and ARB and ARGs in an aqueous solution has been verified.The set of RFD and GDP water treatment systems were built and debugged in this study.In order to reduce the errors of biological tests,The GDP is used to treat E.coli HB101 and its ARGs in high-conductivity water.The RFD is used to degrade NOR in low conductivity water.The degradation rate of NOR in water was 68%when the discharge time is 120 min.The degradation rate of NOR was slightly improved due to the increased concentration of NOR.In acidic solution,the degradation rate of NOR was increased to 82%within 60min discharge treatment.The removal of NOR increased by 99%after the cooperative treatment of the radio frequency discharge and Fenton,and the mineralization of NOR was improved.The energy efficiency of cooperative treatment was better than ozonation and microwave.The results showed that GDP was able to inactivate the antibiotic resistant E.coli,remove the ARGs and reduce the risk of gene transfer.The levels of E.coli determined by 16S rRNA decreased by approximately 4.7 logs within 15 min of discharge treatment.Propidium monoazide-quantitative polymerase chain reaction?PMA-qPCR?tests demonstrated that the cellular structure of E.coli HB101 was destroyed in 15 min.The reduction of tetA,tetR,aphA,tnpA genes was increased to 5.8,5.4,5.3 and 5.5 logs with30 min discharge treatment,respectively.The removal of ARGs from high salinity wastewater was also investigated.The total abundance of ARGs was reduced by 3.9 logs in 30 min.Scavenging tests indicated that hydroxyl radicals?·OH?was the most probable agents for bacteria inactivation and ARGs degradation.In addition,the active chlorine?Cl·and Cl₂?which formed during the discharge may also contribute to the degradation of ARB and ARGs.