WANGLi-ping,YECheng-song,YUXin,et al.UV/Chlorine Disinfection for Inactivation of Staphylococcus aureus[J].China Water & Wastewater,2023,39(13):71-75.
UV/Chlorine Disinfection for Inactivation of Staphylococcus aureus
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第13期
Page:
71-75
Column:
Date of publication:
2023-07-01
- Keywords:
- UV/chlorine disinfection; free radical; Staphylococcus aureus; intracellular DNA; extracellular DNA
- Abstract:
- This paper investigated the performance and mechanism of UV/chlorine process for inactivation of Staphylococcus aureus from the aspects of culturable bacteria number, cell membrane integrity and changes in intracellular and extracellular DNA (iDNA/eDNA) numbers during disinfection. When the dosages of chlorine and UV were 1 mg/L and 120 mJ/cm2, the UV/chlorine process could inactivate all culturable Staphylococcus aureus (7.28-lg CFU/mL), while chlorination alone and UV alone inactivated 5.10-lg CFU/mL and 6.38-lg CFU/mL of Staphylococcus aureus, respectively. The free radical scavenging test showed that the enhanced inactivation of Staphylococcus aureus by the UV/chlorine process was mainly due to the roles of UV and chlorine, and the effects of free radicals could be ignored. The results of flow cytometry (FCM) and scanning electron microscopy (SEM) confirmed that chlorination and UV/chlorine caused bacterial inactivation through the destruction of cell wall and membrane. In addition, UV/chlorine process could effectively remove iDNA and free plasmid, and free radicals showed an obvious plasmid DNA removal ability, while the concentration of eDNA in solution did not increase. In conclusion, the UV/chlorine process promoted the inactivation of Staphylococcus aureus and controlled both intracellular and extracellular genes, which provided a theoretical basis for UV/chlorine disinfection process to control the growth of gram-positive bacteria in water.
Last Update:
2023-07-01