There has been increasing interest in modeling the UV inactivation on airborne microorganisms via the Lagrangian approach as a result of its outstanding features in calculating UV dose with particle trajectory. In this study, we applied the Lagrangian method to model the disinfection performance of in-duct UV lamps on three bacteria: Pseudomonas alcaligenes, Salmonella enterica and Escherichia coli, respectively. For modeling, the airborne bacteria's inactivation was determined by critical survival fraction probability (CSFP) and maximal bearable UV dose (MBUD) methods, respectively. The results indicated that Lagrangian modeling utilizing the MBUD method needs to appropriately evaluate the maximal UV dose (D mb ), which is bearable for airborne microorganisms. The disinfection efficacy obtained by using the CSFP method agreed well with experimental measurements. Within the Lagrangian framework, the recommended empirical value for critical survival fraction (F sc ) was 0.4 for modeling the disinfection efficacy of in-duct UV lamps. Besides, the disinfection efficacies of in-duct UV lamps with full luminous length on P. alcaligenes and E. coli were 100% with Re within the range of 4.11 × 104 to 8.22 × 104. Moreover, the present numerical model was also applied for further validation with inactivation measurements of in-duct UV lamps performed by the U.S. Environmental Protection Agency (EPA). Based on the results, the UV disinfection efficacies obtained by the present modeling method had a closed agreement with EPA experimental results. It deserved to pay more investigations on the optimal value of F sc in further for accurately applying Lagrangian modeling on air UV disinfection.

中文翻译：

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管道内紫外线灯灭活空气微生物的拉格朗日模型

由于拉格朗日方法在计算带有粒子轨迹的紫外线剂量方面的突出特点，人们越来越关注通过拉格朗日方法模拟紫外线对空气微生物的灭活。在这项研究中，我们应用拉格朗日方法模拟管道内紫外线灯对三种细菌的消毒性能：分别是产碱假单胞菌、肠道沙门氏菌和大肠杆菌。对于建模，空气传播细菌的灭活分别由临界存活分数概率 (CSFP) 和最大可承受紫外线剂量 (MBUD) 方法确定。结果表明，利用 MBUD 方法的拉格朗日建模需要适当地评估最大紫外线剂量 (D mb )，这是空气传播的微生物可以承受的。使用 CSFP 方法获得的消毒效果与实验测量结果一致。在拉格朗日框架内，临界存活分数 (F sc ) 的推荐经验值为 0.4，用于模拟管道内紫外线灯的消毒效果。此外，在 4.11 × 104 至 8.22 × 104 范围内，全发光管内紫外线灯对产碱杆菌和大肠杆菌的消毒效果为 100%。此外，本数值模型也适用于通过美国环境保护署 (EPA) 对管道内紫外线灯进行的灭活测量进一步验证。根据结果​​，通过本建模方法获得的紫外线消毒效果与 EPA 实验结果非常吻合。