Study On The Preparation And Sterilization Application Of Acidic Electrolyzed Water Based On A TiO₂-Ru Nanorod Array

Food-borne pathogens pollution is one of the most common safety risks,which may cause serious food safety problems.Among them,Escherichia coli O157:H7 and Staphylococcus aureus are widely distributed and pathogenic,causing serious health problems.Acidic electrolyzed water has been widely used as the sterilizing agent in recent years.It has high-efficient bactericidal effect and many other advantages like broad-spectrum high antimicrobial activity,low cost,high safety,as well as no pollution.However,note that researchers have paid too much attention on the applications of commercial acidic electrolyzed water,while they paid little attention on the design of advanced electrocatalysts with lower cost and higher electrocatalytic performance.Nanoarray materials have attracted much attention in recent years.In this study,a TiO₂-Ru nanorod array material synthesized by hydrothermal and followed air-annealing process was used as the catalytic electrode for the preparation of acidic electrolyzed water.The electrolysis performance and stability of this electrode were then recorded in a home-made diaphragm electrolyzer.Finally,the bactericidal ability to the above two food-borne pathogenic bacteria of the acidic electrolyzed water prepared by the above equipment was tested by a suspension quantitative sterilization experiment.The main results of this study are as follows:（1）The TiO₂-Ru nanorod array electrode was successfully synthesized.The composition and morphology of this material were studied by a series of physical characterizations.It has excellent catalytic performance and can reach a high current density at a low potential of～1.09 V.Long-term durability test shows this electrode could sustain a constant current density of 10 m A cm^-2 for over 20 h.（2）The TiO₂-Ru nanorod array electrode was successfully applied in a home-made diaphragm electrolytic cell.This energy-saving device only needs a low voltage of 1.60 V to reach 10 m A cm^-2 and shows excellent stability in long-term electrolysis.Further,the effects of current density and other conditions on the physical and chemical properties of acidic electrolyzed water were explored.Optimal condition was obtained by comprehensively considering the sterilizing effect,economy and other factors.（3）Acidic electrolyzed water with high available chlorine concentration（ACC）,high oxidation reduction potential（ORP）and low p H value could be prepared through the home-made electrolytic cell.The sterilizing effect of acidic electrolyzed water was further verified.In this part,a suspension quantitative sterilizing method was used to verify the bactericidal ability,and the bacterial suspension was prepared by using a laboratory purified strain.The results showed that the prepared acidic electrolyzed water has high sterilizing ability against both Escherichia coli O157:H7 and Staphylococcus aureus,and the bacterial count decreased by more than 8 log₁₀ CFU m L^-1 in only 15 s.