Filter Test Center, Northeastern University, Shenyang, Liaoning CN-110819, China.
Institute of Environmental Engineering, ETH Zürich, Zürich, CH-8093, Switzerland.
ACS Nano. 2020 Oct 27;14(10):13161-13171. doi: 10.1021/acsnano.0c04782. Epub 2020 Oct 2.
The regeneration of filtering facepiece respirators (FFRs) is of critical importance because of the severe shortage of FFRs during large-scale outbreaks of respiratory epidemics, such as COVID-19. Comprehensive experiments regarding FFR regeneration were performed in this study with model bacteria to illustrate the decontamination performance of the regeneration processes. The results showed that it is dangerous to use a contaminated FFR without any microbe inactivation treatment because the bacteria can live for more than 8 h. The filtration efficiency and surface electrostatic potential of 75% ethanol-treated FFRs were significantly reduced, and a most penetrating particle size of 200 nm was observed. Steam and microwave irradiation (MWI) showed promising decontamination performances, achieving 100% inactivation in 90 and 30 min, respectively. The filtration efficiencies of steam-treated FFRs for 50 and 100 nm particles decreased from 98.86% and 99.51% to 97.58% and 98.79%, respectively. Ultraviolet irradiation (UVI) effectively inactivated the surface bacteria with a short treatment of 5 min and did not affect the filtration performance. However, the UV dose reaching different layers of the FFP2 mask sample gradually decreased from the outermost layer to the innermost layer, while the model bacteria on the second and third layers could not be killed completely. UVI+MWI and steam were recommended to effectively decontaminate the used respirators and still maintain the respirators' filtration efficiency. The present work provides a comprehensive evaluation for FFR regeneration in terms of the filtration efficiencies for 50-500 nm particles, the electrostatic properties, mechanical properties, and decontamination effects.
在大规模呼吸道传染病爆发（如 COVID-19）期间，由于过滤式面罩呼吸器（FFR）严重短缺，因此FFR 的再生至关重要。本研究使用模型细菌对 FFR 再生进行了全面实验，以说明再生过程的去污性能。结果表明，使用未经任何微生物灭活处理的污染 FFR 是危险的，因为细菌可以存活超过 8 小时。75%乙醇处理的 FFR 的过滤效率和表面静电势显著降低，并且观察到最大穿透粒径为 200nm。蒸汽和微波辐照（MWI）显示出有希望的去污性能，分别在 90 和 30 分钟内实现 100%的灭活。经蒸汽处理的 FFR 对 50nm 和 100nm 颗粒的过滤效率分别从 98.86%和 99.51%降低至 97.58%和 98.79%。紫外线照射（UVI）在 5 分钟的短时间内有效地灭活了表面细菌，并且不影响过滤性能。然而，到达 FFP2 口罩样品不同层的 UV 剂量从最外层逐渐减少到最内层，而第二层和第三层的模型细菌无法完全杀死。建议 UVI+MWI 和蒸汽有效对使用过的呼吸器进行去污，同时保持呼吸器的过滤效率。本工作从 50-500nm 颗粒的过滤效率、静电特性、机械性能和去污效果等方面对 FFR 再生进行了全面评估。
