云南宣威肺癌高发区固体燃料燃烧排放颗粒的物理化学特征

Physicochemical characterization of ambient particulate matter emitted from solid fuel combustion in high lung cancer incidence areas in Xuanwei,Yunnan

在云南宣威肺癌高发区采集了固体燃料(煤炭、木材)燃烧排放的大气颗粒物样品,利用扫描电镜(scanning electron microscopy,SEM)、能量色散X射线光谱仪(energy dispersive X-ray spectroscopy,EDX)对796个颗粒物进行了分析.根据颗粒物的显微特征和化学元素组成,将其分为矿物颗粒物、飞灰、烟尘集合体和未识别颗粒物4类.采用P(X)值法将矿物颗粒物进一步分为富Si、富S、富Ca、富Fe、富Ti、富Al、富Na和其他8种不同类型,其中富Si、富Ca、富Fe、富S分别占燃煤颗粒物和生物质颗粒物的44.47%,20.49%,8.85%,1.22%和55.91%,17.27%,6.36%,2.27%.化学元素分析结果显示:颗粒物中Al,Fe,Ca,Mg等地壳元素的质量浓度较高,重金属化学元素的质量浓度较低;煤炭燃烧排放的颗粒物的化学元素分析结果与单颗粒分析结果之间存在较好的正相关关系(R2=0.63).

Samples of atmospheric particulate matter from solid fuel(coal and wood)combustion were collected in the high lung cancer incidence area of Xuanwei,Yunnan,and796 particles emitted by combustion were analysed by scanning electron microscopy(SEM)with energy dispersive X-ray spectroscopy(EDX).According to the microscopic characteristics and chemical element compositions of the particles,the particles were divided into four categories,namely mineral particles,fly ash,soot aggregates,and unidentified particles.The P(X) method was used to further classify the mineral particles into eight different types,namely Si-rich,S-rich,Ca-rich,Fe-rich,Ti-rich,Al-rich,Na-rich,and others.The percentages of Si-rich,Ca-rich,Fe-rich,and S-rich particles in coal-fired particulate matter and combustion biomass particles accounted for 44.47%,20.49%,8.85%,1.22% and 55.91%,17.27%,6.36%,2.27%,respectively.The chemical analysis results showed that the mass concentrations of the crustal elements Al,Fe,Ca,and Mg in the particles were relatively high,and the mass concentrations of heavy metal elements were relatively low.There was a positive correlation(R2=0.63) between the results of the chemical analysis of particulate matter emitted from coal combustion and the results of single particle analysis.