Characterisation of iron-rich atmospheric submicrometre particles in the roadside environment
Characterisation of iron-rich atmospheric submicrometre particles in the roadside environment
复制标题
路边环境中富铁大气亚微米颗粒的表征
DOI：
10.1016/j.atmosenv.2016.05.040
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发表时间：
2016
影响因子：
5
通讯作者：
Sanderson P
中科院分区：
文献类型：
--
作者：
Sanderson P
由于其潜在的健康影响，人类暴露于环境金属纳米颗粒是一个非常感兴趣的领域。在路边环境中发现的周围金属纳米颗粒是由内燃机和刹车、轮胎和路面的磨损造成的。对在英国两个城市站点收集的亚微米大气颗粒物进行了详细的表征。研究发现，从路边采样点采集的许多金属纳米颗粒都富含铁。富Fe纳米颗粒可分为（1）高Fe含量（约90重量%），其中每种合金元素小于1重量%;和（2）中等Fe含量（<75重量%），其中锰和硅含量高。这两个集群包含一个变量混合的次要成分，锰，硫和硅是最重要的高铁组。中Fe组还含有Zn、Cu、Ba、Al和Ca。富铁纳米粒子的初级粒径在20~30 nm之间，但也可观察到一些大得多的粒子，最大可达100 nm左右，沿着出现一些10 nm或更小的非常小的粒子，这些粒子往往会聚集形成直径为100 nm~1 μ m的团簇。观察到的富铁颗粒是氧化物，呈球形或多面规则多面体的形式。EELS分析表明，高铁组和中铁组均含有FeO、Fe_3O_4、α-Fe_2O_3和γ-Fe_2O_3颗粒，其中γ-Fe_2O_3颗粒最多。未观察到不同铁氧化物的内部混合。
Human exposure to ambient metallic nanoparticles is an area of great interest owing to their potential health impacts. Ambient metallic nanoparticles found in the roadside environment are contributed by combustion engines and wear of brakes, tyres and road surfaces. Submicrometre atmospheric particles collected at two UK urban sites have been subject to detailed characterisation. It is found that many metallic nanoparticles collected from roadside sampling sites are rich in iron. The Fe-rich nanoparticles can be classified into (1) high Fe content (ca 90 wt%) with each alloying element less than 1 wt%; and (2) moderate Fe content (<75 wt%) with high manganese and silicon content. Both clusters contain a variable mix of minor constituents, Mn, S and Si being most important in the high-Fe group. The moderate Fe group also contains Zn, Cu, Ba, Al and Ca. The Fe-rich nanoparticles exhibit primary particle sizes ranging between 20 and 30 nm, although some much larger particles up to around 100 nm can also be observed, along with some very small particles of 10 nm or less. These tend to agglomerate forming clusters ranging from ∼200 nm to 1 μm in diameter. The iron-rich particles observed are oxides, taking the form of spheres or multifaceted regular polyhedra. Analysis by EELS shows that both high- and moderate-Fe groups include particles of FeO, Fe3O4, α-Fe2O3and γ-Fe2O3of which γ-Fe2O3is the most prominent. Internal mixing of different Fe-oxides is not observed.