绵阳市4月份城郊大气中PM2.5矿物及微生物特性分析

Characteristics of PM_(2.5) in the Suburb of Mianyang City, China in April

2012年4月份对绵阳市城郊大气PM2.5进行了连续4次采样,而后利用SEM、XRD/XRF等测试手段对采集后PM2.5颗粒物矿物特性进行了分析,并利用自然沉降法和滤膜稀释法两种方法对大气微生物浓度进行了分析。采样结果表明,通常情况下所测大气中PM2.5浓度可以达到新订《环境空气质量标准》标准的要求,且雨后明显降低,风沙天气或人为焚烧则会导致PM2.5浓度大幅升高;物相分析可知,绵阳城郊大气的矿物种类主要有石英、石膏、方解石、伊利石、高岭石等;SEM分析发现,采集的PM2.5滤膜上大多为亚微米系颗粒物,且颗粒物多数表面光滑无棱角;微生物浓度分析可知,大气中粒径≤2.5μm的微生物个数偏少,约占总数的1/100。

Atmospheric PM2.5was sampled for four times in the suburb of Mianyang city,China in April 2012.SEM,XRD and XRF techniques were used to determine the mineral characteristics of the samples,meanwhile,methods of natural sedimentation and filtration membrane diluting were applied to test the concentration of airborne microbiology.Results showed that in normal condition,concentration of the atmosphere PM2.5 in Mianyang met the requirement of the new national standard-ambient air quality standard（AAQS）,and PM2.5 concentration decreased when it rains,while increased drastically with sand weather or anthropic burning.According to the results of phase analysis,the mainly mineral compositions were quartz,gypsum,calcite,illite,and kaolinite.The SEM observation showed that collected PM2.5 was mainly consist of submicron particles,and the surface of PM were mostly smooth.From the microbiology mass of atmosphere,it is clear that microbiology with size ≤2.5 μm was rare,occupied only about 1% of the sample.