青岛市不同下垫面微生物气溶胶分布特征

分别在青岛市市区街道、海滨区域、饮用水水源地、城市垃圾填埋场和人工湿地污水处理厂设置监测点,分析比较不同下垫面空气细菌和真菌浓度、日变化和粒径分布. 结果表明:5个下垫面空气细菌浓度依次为城市垃圾填埋场>市区街道>饮用水水源地>海滨区域>人工湿地污水处理厂,真菌浓度依次为城市垃圾填埋场>人工湿地污水处理厂>饮用水水源地>市区街道>海滨区域,其中城市垃圾填埋场空气细菌和真菌浓度最高,分别为(613.1±68.9)、(1300.4±74.3)CFU/m3,其他下垫面空气的细菌和真菌浓度分别在(155.5±14.2)～(596.6±396.4)和(401.9±78.7)～(994.7±63.4)CFU/m3之间. 海滨区域空气细菌浓度下午明显高于上午和中午,其他下垫面表现为上午>下午>中午,但无显著性差异；市区街道、饮用水水源地、人工湿地污水处理厂的空气真菌浓度日变化表现为上午>中午>下午,城市垃圾填埋场则始终升高,除人工湿地污水处理厂和城市垃圾填埋场不同时段间空气真菌浓度有显著性差异外,其余下垫面无显著性差异. 细菌气溶胶粒径分布为F1级(粒径>7.0μm)最高,呈偏态分布；真菌气溶胶粒径呈对数正态分布,除城市垃圾填埋场峰值出现在F3级(3.3~4.7μm)外,其余下垫面均出现在F4级(2.1~3.3μm). 不同下垫面细菌气溶胶中值直径在2.8~4.6μm,存在差异；而不同下垫面空气真菌气溶胶中值直径均在2.0μm左右,无显著性差异. 

Studies on Microbial Aerosol of Different Underlying Surfaces in Qingdao City

To determine dynamic changes of airborne microbes,concentration of different underlying surfaces in Qingdao City, monitoring points were set up in five different underlying surfaces (city streets, coastal area, drinking water source, municipal landfill site, and constructed wetlands for wastewater treatment). Airborne microbes were collected by SAS ISO100and Andersen six stage sampler. The distributions of concentration and size, diurnal variations were systematically studied. Results showed that the concentrations of airborne bacteria were decreasingly ordered:municipal landfill site＞city streets＞drinking water source＞coastal area＞constructed wetlands for wastewater treatment. The concentrations of airborne fungi were decreased as:municipal landfill site＞constructed wetlands for wastewater treatment＞drinking water source＞city streets＞coastal area. Concentrations of bacteria and fungi in the airborne were (613.1±68.9)and (1300.4±74.3)CFU/m3, which were significantly higher in landfill site than those in other underlying surfaces. Concentrations of bacteria ranged from (155.5±14.2) to (596.6±396.4)CFU/m3, while concentrations of fungi were between (401.9±78.7) to (994.7±63.4) CFU/m3in the other underlying surfaces. The concentration of airborne bacteria in coastal area was significantly higher in the afternoon than that in the morning and noon. The concentrations of airborne bacteria in the other underlying surfaces were basically the same as within experimental error.Concentration distributions of fungi were different among underlying surfaces. The concentrations of airborne fungi in city streets, drinking water source, and constructed wetlands for wastewater treatment were ordered as morning＞noon＞afternoon, while the concentration of airborne fungi in municipal landfill site showed the sequence morning＜noon＜afternoon. However, there was no statistically significant difference (P>0.05) between different times of the day except for constructed wetlands and municipal landfill site. Bacterial aerosol in five underlying surfaces were mostly distributed in stage F1(>7.0μm) with airborne bacteria showing a skewed distribution. The trend of the aerosol particle size distribution of airborne fungi was basically similar in five different underlying surfaces with airborne fungi showing normal logarithmic distribution. The maximum was in stage F4(2.1-3.3μm) except for that municipal landfill site in stage F3(3.3-4.7μm). There were differences of airborne microbes CMD (counted median diameter) among underlying surfaces. The median diameters of airborne bacteria ranged from 2.8-4.6μm. The median diameters of fungi were about 2.0μm. Slight difference existed in CMD of fungi between five different underlying surfaces.