紫外活化过硫酸钠灭活水中噬菌体MS2的特性及机制

Characteristics and Mechanisms of Bacteriophage MS2 Inactivation in Water by UV Activated Sodium Persulfate

水环境中的病毒对常见的消毒技术有较强的抵抗力.为了开发水中病毒的高效灭活技术,以噬菌体MS2为对象,研究紫外活化过硫酸钠(UV/PS)体系灭活病毒的特性和机制.采用双层平板法对噬菌体MS2进行定量检测,研究UV/PS对水样中噬菌体MS2的灭活率和动力学特征,并考察PS用量、pH值和噬菌体初始浓度等因素对灭活效果的影响.利用透射扫描电镜观察UV/PS处理前后噬菌体的形貌,利用电子顺磁共振波谱法确认反应体系中存在的自由基种类.在自由基淬灭实验的基础上,分析计算UV/PS体系中各因素对噬菌体灭活的贡献率.结果表明,当紫外辐照强度为160μW·cm^(-2)时,UV/PS处理4min即可去除4.39 lg的噬菌体MS2,较单独使用同样辐照剂量的UV消毒灭活率高1.44 lg.UV/PS体系对噬菌体MS2的灭活动力学过程符合一级反应动力学模型.增加体系中的PS初始浓度能明显提高对噬菌体的灭活率和灭活速率,而pH和噬菌体初始浓度对UV/PS灭活噬菌体的影响较小.UV/PS处理可导致噬菌体的衣壳破损,促进了噬菌体颗粒团聚.UV/PS体系中存在SO_(4)^(-)·和·OH,是噬菌体MS2灭活的重要因素.·OH比SO_(4)^(-)·对噬菌体MS2灭活的贡献更大.

Viruses in the aquatic environment have strong resistance to common disinfection techniques.To contribute to the development of efficient virus inactivation technologies,the characteristics and mechanisms of virus inactivation in a UV activated sodium persulfate(UV/PS)system were studied.The inactivation rate and kinetic characteristics of bacteriophage MS2 in water samples by the UV/PS were studied.The effects of PS dosage,pH,and the initial concentration of bacteriophages on the inactivation effect were also investigated.Furthermore,the morphologies of phages before and after UV/PS treatment were observed by transmission scanningelectron microscope,and the free radicals in the reaction system were identified by electron paramagnetic resonance spectroscopy.By means of a free radical quenching experiment,the contribution rate of various factors in the UV/PS system to phage inactivation was also analyzed and calculated.The results showed that when the UV irradiation intensity was160μW·cm^(-2),the phage MS2 of 4.39 lg could be removed after UV/PS treatment for 4 min,which was 1.44 lg higher than that of the same UV dose alone.The inactivation of phage MS2 by the UV/PS system was in accordance with the first-order kinetic model.Increasing the initial concentration of PS in the system significantly improved the inactivation rate of phages,while pH and the initial concentration of phages had little effect on the inactivation rate.UV/PS treatment damages the capsid of phages and promotes the aggregation of phage particles.The presence of SO_(4)^(-)·and·OH in the UV/PS system was an important factor for the inactivation of MS2 phages.Finally,·OH contributed more to MS2 phage inactivation than SO_(4)^(-)·.