Simultaneous removal of ARB and ARGs by cathode flow-through reactor coupled with electro-activated permanganate process
The issue of antibiotic resistance has received worldwide attention,especially its spread in water environment.To address this challenge,a cathode flow-through reactor was established in this study,then the effects and mechanisms of electro-activated permanganate on antibiotic removal,inactivation of antibiotic resistant Escherichia coli(AR E.coli),and reduction of resistance genes(ARGs)were investigated.The effects of permanganate dosage,current density,initial pH value,actual water bodies and water matrices,including humic acid(HA),chloride ion(Cl-),bicarbonate(HCO3-),hydrogen phosphate(HPO42-),on the inactivation of AR E.coli were investigated.The results showed electric cathode-permanganate process had significant synergistic disinfection effects at the permanganate concentration of only 7 pmol·L-1,the current density of 12.55 mA·cm-2,and the initial pH 5,achieving 4.92 log removal rate after 15 minutes.Meanwhile,the process exhibited a significant removal effect on the ARGs carried by the bacteria,resulting in a 3.89 log reduction(99.99％)in five ARGs.In addition,this process can also efficiently remove antibiotics,and could remove 96.4％tetracycline.Scanning electron microscopy images revealed that the treated bacteria were severely damaged and their cell membrane integrity was disrupted.Through further confirmation,it was found that lipid on the cell membrane were oxidized,while intracellular substances were gradually released and degraded,resulting in complete inactivation of AR E.coli.Detection of reactive manganese species and masking experiments identified Mn(Ⅲ)aq as the primary disinfecting active species.In actual water,the process showed an excellent removal ability of AR E.coli.The presence of Cl-had no effect on the inactivation of AR E.coli,while HA,HCO3-and HPO42-all inhibited the inactivation process.The above result provides a reference for inhibit the spread of antibiotic resistance in aquatic environments.
AR E.colidisinfectionARGspermanganateelectrochemistry
国家科技期刊平台
NSTL
万方数据
