紫外消毒动力学模型及影响因素

Kinetic Model and Influencing Factors of UV Disinfection

采用静态紫外辐照装置,探讨Chick-Waton模型、Collins-Selleck模型、Hom模型和Biphasic数学模型对测试情况中紫外灭大肠杆菌的适应性,研究大肠杆菌生长阶段对消毒动力学的影响。采用响应面试验方法,通过建立数学模型,解释紫外辐照时间和辐射强度对杀菌效果的共同作用关系。结果表明:与其他3种模型相比,Biphasic模型拟合R2为0.9950,最接近1,RMSE为0.2312,小于0.5。对数期、适应期和稳定期的临界紫外剂量分别为50、200、160 mJ/cm^2,即接近拖尾区的临界紫外剂量最小为对数期。回归分析表明,大肠杆菌的照射时间F值为423.04,高于紫外强度F值212.77。经探究,确立Biphasic模型为试验条件下紫外灭活大肠杆菌的动力学模型。紫外灭活大肠杆菌的功效受到细菌生长阶段的直接影响,同剂量的紫外照射对对数期的大肠杆菌灭菌效果最为明显。紫外线辐照时间和强度对灭活大肠杆菌可以起到协同增效作用,相比之下辐照时间的影响更大。

The adaptability of four kinetic models to UV sterilization under experimental conditions including Chick-Waton model,Collins-Selleck model,Hom model and Biphasic model was discussed by using static UV-irradiation device,and the influence of Escherichia coli growth stage on disinfection kinetics was studied.The response surface model was used to establish a mathematical model to explain the interaction between UV irradiation time and radiation intensity on bactericidal effect.Results showed that,Biphasic model was the most relevant compared to the other three models,and the R2 of E.coli was 0.9950 closing to 1 as well as the RMSE was 0.2312 less than 0.5.Critical UV dose of logarithmic E.coli was the smallest,which was 50 mJ/cm^2.Critical UV doses during the acclimation and stationary phases were 200 mJ/cm^2 and 160 mJ/cm^2,respectively.Regression analysis showed that,the F of irradiation time was 423.04,which was higher than that of UV intensity(212.77).Biphasic model was the most suitable for UV disinfection under the conditions of the study.State of the bacteria at the initial stage of inactivation could affect the effect of the UV inactivation and the log phase E.coli was the most sensitive to UV irradiation.UV irradiation time and radiation intensity have synergistic interaction on E.coli inactivation and the former has a greater impact on sterilization.