Control of Virus Aerosol by Silver Nanoparticle/Nanoscale Silicate Platelet Modified Filter in Indoor Environment
Date Issued
2016
Date
2016
Author(s)
Yang, Chun-Chun
Abstract
Bioaerosols is one of the major issue associated with indoor air quality guidelines, which can be removed by filter filtration device. In this study, we used Silver nanoparticle/ Nanoscale silicate platelet (AgNP/NSP) modified air filter medium to prepare a new antibacterial filter. Compared with the widespread use of nanosilver, it has a characteristics of high antimicrobial activity and low cytotoxicity, which can improve the safety of the use of nanosilver. The study against the virus (λ vir) to carry on simulation system test experiments of AgNP/NSP of experimental chamber and HVAC (Heating, Ventilation, Air Conditioning simulation system), including filtration efficiency, survival ratio and the antimicrobial efficiency,. The results integrate with the research from Chen (2015) modified filter of bacteria (E.coli) and fungus (yeast) control the indoor environment, to explore the removal between different species. According to the results of continuous flow filtration test for four types of filers(un-modified filter, AgNP/NSP modified filter with 12.6ppm, 31.5ppm, and 63ppm Ag), the filtration efficiency decreased by 2-23% and 3-21% at RH=30% and RH=70%, respectively. Compared the filtration efficiency of three microorganism, the average filtration efficiency of λ vir and yeast up to 90%, while the E.coli was about 80%, due to different filtering mechanisms of each species. Using One-way ANOVA statistical test analysis showed that, different concentrations of the modified λ vir filtration efficiency of the filter (P-value <0.001) and filtration efficiency between different strains (P-value <0.05) has statistically significant difference. In HVAC filter testing simulation system, after installation filter will increase λ vir filter performance, installation of unmodified filter lift 12.2% filtration efficiency. Installation of the modified filter enhance 2.52% filtration efficiency, the filtration efficiency of unmodified filter is 9.7% higher than the modified filter under environmental condition at RH=30%. Not installed filter filtration efficiency is 11.1% higher than installation of unmodified filter, filtration efficiency of modified filter is 27.4% better than the unmodified filter under environmental condition at RH=70%. Comparison the filtration efficiency of the results from three microorganism, the filtration efficiency of filter without installed, installation with unmodified, and modified filter are presented as E.coli > λ vir > yeast. The results using the One-way ANOVA statistical analysis showed a statistically significant difference in different filter filtration efficiency (P-value = 0.021) of λ vir under environmental condition at RH = 70%. Filtration efficiency between the different strains also showed significant difference (P-value <0.05), further paired comparisons of strains by Tukey Test, which showed the most significant difference between bacteria and fungi (P-value <0.01). The study of antibacterial properties of AgNP/NSP modified filter, results show that E.coli, yeast, and λvir in experimental chamber for 10 minutes, the AgNP/NSP modified filters of 63 ppm silver concentration demonstrated 95.1%, 91%, and 28.7% antimicrobial efficiency at relative humidity of 30%, 70% and 30%, respectively. HVAC system for yeast and λ vir AgNP/NSP modified filter for 12 hours at relative humidity 30% and 70%, modified filter demonstrated 29% and 23% antimicrobial efficiency, and 7% and 32.3% antimicrobial efficiency, respectively. Therefore, the results indicated that the filters modified with AgNPs/NSP could provide antimicrobial effect for bioaerosols including bacterial, yeast, and virus aerosols. The results of the study can be applied in hospitals, homes, offices or public places, such as indoor air filters of anti-bacterial filter or air cleaners, masks and other commercial goods to avoid biological aerosols affect human health, and safeguard the health of citizens.
Subjects
bioaerosol
silver nanoparticle/nanoscale silicate platelet (AgNP/NSP)
antimicrobial filter
filter
Type
thesis