『Abstract
The study of mineral components in respitable particles (particulate
matter with diameter less than 10 μm, PM10)
in ambient air is important in understanding and improving air
quality. In this study, PM10 samples were
collected in various areas around Beijing during 2002〜2003, including
an urban setting, a satellite city and a rural area. The mineralogical
composition of these PM10 samples was studied
by X-ray diffraction (XRD), environmental scanning electron microscopy
/ and energy-dispersive X-ray analyzer (ESEM/EDX). The results
indicated that mineral composition of PM10
in different seasons and in different region varied significantly.
Mineral mass concentration in Beijing PM10
reached the highest percentage in the spring and fell to the lowest
level in the autumn. The minerals in the spring PM10
were dominated by clay minerals and quartz, followed by plagioclase,
K-feldspar, calcite, dolomite, hematite, pyrite, magnesite, gypsum
and laumontite as well as some unidentified materials. Fewer mineral
types were collected in summer, however some new components, including
K(NH4)Ca(SO4)2・H2O, NH4Cl and As2O3・SO3 were noted to be present,
suggesting that atmospheric chemical reaction in Beijing air were
more active in summer than in other seasons. Mineral components
in Beijing urban air were at a higher percentage with fewer phases
than that in satellite city air. In conclusion, there was considerable
variation in mineral components in PM10 samples
collected in different seasons and areas, which reflects the related
air quality of sampling areas.
Keywords: Beijing PM10; Mineralogical composition;
X-ray diffraction (XRD
); Elemental scanning electron microscopy with energy dispersive
(ESEM/EDX)』
1. Introduction
2. Experimental
2.1. Sampling field site
2.2. Particle sampling
2.3. XRD analysis
2.4. Scanning electronic microscopy/Energy dispersive X-ray(SEM/EDX)
3. Results and discussion
3.1. X-ray diffraction analyses of PM10
samples
3.2. ESEM/EDX analysis of PM10
3.3. Mineral phases in Beijing PM10 collected
in different regions
3.4. Comparison of mineralogical study of airborne particles
4. Conclusions
Acknowledgment
References