电化学消毒法对水中大肠杆菌的灭活特性

本研究通过电化学消毒小试装置,系统考察了电极板材料、极板间距、p H、水温、Na Cl浓度等因素对水中大肠杆菌CGMCC 1.3373灭活效果的影响,并进一步考察了电化学消毒对抗生素抗性大肠杆菌CGMCC 1.1595的灭活效果及其抗性变化.结果发现,在相同的电化学消毒条件下,阳极采用钌铱涂层的钛电极板的灭活效果显著优于铅涂层和铱钽涂层电极板,并且极板间距为50 mm时灭活率最高.进一步研究表明,电化学消毒法对大肠杆菌的灭活率随水的p H升高而降低,随水温和Na Cl浓度升高而升高.在相同消毒条件下,电化学法对四环素抗性大肠杆菌的灭活率显著低于普通大肠杆菌.消毒后存活的抗性菌对四环素、青霉素、氯霉素的抗性,随消毒时间延长呈现先下降后上升的规律.

Inactivation of antibiotic-sensitive and antibiotic-resistant E. coli in water by electrochemical disinfection

In this study, four electrochemical disinfection devices were set up and the effect of anode coating materials, plates distance, pH, water temperature and NaCl concentration on the inactivation ratio of E. coli CGMCC 1.3373 were studied. Then, the inactivation of tetracycline-resistant E. coli CGMCC 1.1595 by electrochemical disinfection was also studied. The results showed that the titanium anode coated with ruthenium/iridium had a significant higher inactivation ratio than those coated with plumbum or iridium/tantalum under the same disinfection conditions. The device with a plate distance of 50 mm exhibited the highest inactivation ratio among the four devices. Further study indicated that the inactivation ratio by electrochemical disinfection will decrease when pH rise, while the ratio will increase when water temperature or NaCl concentration rise. Under the same disinfection conditions, the inactivation ratio of tetracycline-resistant E. coli was significantly lower than antibiotic-sensitive E. coli CGMCC 1.3373. After disinfection, the resistance level of survived tetracycline-resistant E. coli to tetracycline, penicillin and chloramphenicol dropped firstly and then increased as the disinfection time extended.