奈米矽片銀改質濾材控制室內病毒氣膠之研究

Abstract

生物氣膠為室內空氣品質規範的項目之一，可透過濾材過濾裝置來去除。本研究使用奈米矽片銀（Silver nanoparticle/Nanoscale silicate platelet, AgNP/NSP）改質空氣過濾濾材以製備新型抗菌濾材，與廣泛使用的奈米銀相比，具高抗菌性和低生物毒性之特性，可提高奈米銀使用之安全性。本研究針對病毒(λ vir)進行奈米矽片銀抗菌濾材之微型艙和HVAC（Heating, Ventilation, Air Conditioning simulation system）模擬系統測試實驗，包括過濾效率、濾材上微生物存活率和抗菌效能，實驗結果與陳(2015)改質濾材控制室內細菌(E.coli)與真菌(yeast)之研究整合，探討不同菌種間的去除差異。 四種濾材（未改質、12.6 ppm、31.5 ppm與63 ppm之奈米矽片銀改質濾材）連續過濾測試結果，經改質後濾材造成結構改變，會降低λ vir氣膠過濾效率，在RH=30%和RH=70%環境下過濾效率分別降低2−23%和3−21%。比較三種微生物之過濾效率，λ vir與yeast平均過濾效率高達90%，而E.coli平均過濾效率約為80%，因各菌種過濾機制不同所致。用One-way ANOVA統計檢定分析結果顯示，不同改質濃度濾材之λ vir過濾效率(P-value < 0.001)和不同菌種間之過濾效率(P-value < 0.05)具有統計上顯著性差異。 HVAC模擬系統過濾測試，在RH=30%環境下，裝設濾材後會提高λ vir過濾效能，裝設未改質濾材提升12.2%過濾效率，裝設改質濾材提升2.52%過濾效率，未改質濾材過濾效率高於改質濾材9.7%。RH=70%環境下，未裝設濾材過濾效濾高於裝設未改質濾材11.1%，改質濾材過濾效率優於未改質濾材27.4%。比較三種微生物之過濾效率，未裝設濾材、裝設未改質與改質濾材之過濾效率結果呈現為E.coli＞λ vir＞Yeast，用One-way ANOVA統計檢定分析結果顯示，不同濾材之λ vir過濾效率在RH=70%具有統計上顯著性差異（P-value =0.021），不同菌種間之過濾效率也呈現顯著差異性(P-value < 0.05)，再進一步經Tukey Test兩兩菌種配對比較，其結果顯示細菌和真菌差異最顯著（P-value < 0.01）。 奈米矽片銀改質濾材之抗菌性能研究，結果顯示微型艙對E.coli10分鐘在相對濕度30 %下，63 ppm奈米矽片銀可提供95.1 %抗菌率。對yeast在10分鐘相對濕度70 %下，63 ppm奈米銀矽片可提供91 %抗菌率。對λ vir在10分鐘相對濕度30 %下，63 ppm奈米矽片銀可提供28.7 %抗菌率。HVAC系統對yeast和λ vir奈米矽片銀改質濾材放置12小時，在RH=30%環境下可提供29 %和23 %抗菌率，在RH=70%環境下分別可提供7 %和32.3 %抗菌率，顯示出奈米矽片銀改質濾材對細菌、真菌和病毒氣膠具有抗菌效果。 本研究成果可應用於醫院、家庭、辦公室或公共場所等室內環境空氣過濾之抗菌濾材或空氣清淨機、口罩等商業化的商品上，避免生物氣膠影響人體健康，以保障國民健康。

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.