环境条件对微生物在滤料表面生长繁殖的影响

Effect of Environmental Conditions on Microbial Growth on Filter Media

针对在适当的空气环境条件下,中央空调机组或大型客机环控系统中空气过滤器拦截的微生物可能在过滤器上大量生长繁殖的情况,挑选常用的玻璃纤维过滤材料,对其进行染菌,控制空气环境条件下培养,从而研究不同温湿度环境条件、滤料含水量以及不同滤料结构对微生物在滤料上生长繁殖的影响.结果表明:温度对含水滤料表面微生物最大生长繁殖量没有明显影响;在37,℃、90%相对湿度条件下的细菌最大生长繁殖量大约为加水滤料上的1/2,且大于相同温度下的低湿条件最大生长繁殖量;17,℃时,不同相对湿度条件下均没有生长趋势;低效滤料更适宜微生物生长.上述结论说明长期处于高湿度下的空气过滤器是最容易被微生物驻留并生长繁殖的部件,容易形成微生物二次污染.

Suitable thermal environment conditions in the air-conditioning systems of building or the environmental control systems of aircraft cabin create great potential for microbial growth on the air filter media. To study the effects of environmental conditions on microbial growth, such as temperature, relative humidity（RH）, moisture content of the filter media and filter structure, glass fiber filter media were selected for study. B. subtilis was selected as the target microorganism. Experimental results show that the maximal population density of the B. subtilis growth on totally wetted filter media is almost not affected by temperature. The maximal population density at RH=90% is about half of that on totally wetted media, and is higher than that at low humidity at 37 ℃. At 17 ℃, no growth appears in any humidity level. Microorganisms are more likely to grow on low efficiency filter media. All of these results showed that air filters consistently used in high temperature and humidity environment are the most likely units for potential components microbial growth, thus making it easy to cause secondary contamination of the indoor air.