臭氧对再生水中指示病原微生物的灭活特性

以臭氧投加量(TOD)为臭氧消耗剂量评价指标,研究了北京市某实际再生水中臭氧对大肠杆菌及枯草芽孢的灭活特性,以及消毒过程中臭氧对溶解性有机碳(DOC)、色度、UV254、荧光强度的去除效果。在此基础之上,分析了色度与指示病原微生物灭活特性之间的相关性。结果表明,臭氧对大肠杆菌及枯草芽孢的灭活特性与余臭氧浓度有关。当水中无法检测到余臭氧时,随着TOD的增加,大肠杆菌灭活率增加的速率较慢,TOD增加 3 mg/L,灭活率增加了1.5 log。枯草芽孢则无显著灭活。当水中余臭氧浓度大于0时,大肠杆菌灭活率增加的速率快速提升,TOD增加 3 mg/L,灭活率增加了3 log。枯草芽孢灭活率也随TOD的增加而显著增加。消毒过程中,DOC无显著变化,而臭氧对色度、UV254、三维荧光强度的去除效果显著。当色度随TOD的增加而趋于稳定时,水中余臭氧浓度开始显著上升,预示着指示病原微生物开始进入高效灭活阶段。同时,进水色度越大,指示病原微生物进入高效灭活阶段所需的TOD越大。

Inactivation characteristics of pathogenic microorganisms with ozone in reuse water

The inactivation characteristics of Escherichia coli and Bacillus subtilis spores,the removal efficiency of dissolved organic carbon(DOC),color,UV254 and fluorescence intensity with ozone were investigated in a practical reuse water in Beijing.The transferred ozone(TOD) was used as ozone consumption dose.Furthermore,the correlation between inactivation characteristics of pathogenic microorganisms and color was analyzed.Results showed that inactivation characteristics of Escherichia coli and Bacillus subtilis spores with ozone were associated with residual ozone concentration(CR) in water.When CR was lower than the detection limit,the inactivation rate of Escherichia coli increased slowly with the increase of TOD.When TOD increased 3 mg/L,the inactivation rate increased 1.5 log.No significant inactivation of Bacillus subtilis spores was observed.When CR was greater than 0,the inactivation rate of Escherichia coli increased much more quikly with the increase of TOD.When TOD increased 3 mg/L,the inactivation rate increased 3 log.The inactivation rate of Bacillus subtilis spores also increased quickly with the increase of TOD.In the ozone disinfection process,no significant changes in DOC were observed.But the removal efficiency of color,UV254 and fluorescence intensity was obvious.When color no longer changed with the increase of TOD,CR in water began to rise quikly and pathogenic microorganisms began to enter into efficient inactivation phase.