BDD电极电化学杀灭芽孢的特性与机理

Performance and Mechanism of B. subtilis Spores Inactivation in Electrochemical Oxidation Using Boron-doped Diamond

为保证消毒彻底性,文章采用掺硼金刚石膜电极电化学氧化技术杀灭芽孢,并研究其特性与机理。结果表明,在低浓度(2.5 mmol/L)的氯离子体系中即可实现对芽孢的快速灭活,证明此技术具有巨大实用价值。溶液性质对BDD电极电化学杀灭芽孢有显著影响。随氯离子浓度提高,电解产生的活性氯增加,芽孢灭活率随之升高;而p H会影响活性氯的组成形式,随pH降低,氧化能力较强的HOCl比例增大,芽孢灭活效率提高;碱度会消耗·OH进而减少活性氯产生,从而降低芽孢灭活率;天然有机物与芽孢竞争体系中的活性氯,进而减弱芽孢灭活效果。SEM和脂质过氧化结果表明,在氯盐体系电解杀灭芽孢过程中,电致活性氯会优先穿透到芽孢内部发生破坏作用,而对芽孢表面的破坏不显著。

In order to guarantee the thorough disinfection, the electrochemical oxidation technology by employing the boron-doped diamond(BDD) anode is used for spores inactivation. The performance and mechanism of B. subtilis spores inactivation by BDD anode system are systematically investigated. Results show that the effective inactivation of B. subtilis spores is achieved in the presence of chloride ions at low concentration(2.5 mmol/L). The water quality parameters show significant impact on B. subtilis spores inactivation. With the increase of chloride concentration, the active chlorine produced by electrolysis increases and the inactivation rate of B. subtilis spores increases. pH can affect the composition of active chlorine, and with the decrease of p H, the proportion of HOCl with strong oxidation capacity increases, and the inactivation efficiency of B. subtilis spore improves. The alkalinity can consume the ·OH and then reduce the production of active chlorine, thus reducing the inactivation rate of B. subtilis spore. The competition between natural organic matter and B. subtilis spore for active chlorine reduces the inactivation of B. subtilis spore. The SEM images and the lipid peroxidation results show that the generated active chlorine species have high permeability to the cell membrane, the intracellular damages are pronounced and the cell surface damage is negligible during the electrochemical inactivation of B. subtilis spores.