A novel three-dimensional galvanic cell enhanced Fe2+/persulfate system: High efficiency, mechanism and damaging effect of antibiotic resistant E-coli and genes

A novel and efficient three-dimensional electrode galvanic cell enhanced Fe2+/persulfate (3D-GFP) system was used to inactivate antibiotic resistant E. coli (AR E. coli) for the first time. The 3D-GFP system was compared with two-dimensional electrode GFP. The 3D-GDP system obviously had a better disinfection effect than the 2D electrode GDP and achieved a 4.6 log disinfection of bacteria within 10 min. Several disinfection experiments were conducted to evaluate the impact of operational conditions (i.e. granular active carbon (GAC) dosage, initial bacteria concentration, additional Cl- content and repetitive use of recycled GAC) on the 3D-GFP process. The stability of GAC in this system was confirmed by the excellent disinfection performance demonstrated in the sixth repetitive test. Sulfate radicals and hydroxyl radicals were identified as the factors responsible for disinfection. Biologically, lipid peroxidation, membrane permeability and potential, Ca2+ leakage, ATP level, ATPase activity, removal of DNA and antibiotic resistance genes ampC were analysed to demonstrate the toxicological effect of 3D-GFP on AR E. coli. These results highlighted 3D-GFP as a promising disinfection method.