[Physicochemical characterization of the PM10 in ambient air of northwestern Beijing urban area during heating-period].

ABSTRACT

Based on monitoring data, the daily and day-to-day changes of PM10 mass concentrations in northwestern Beijing urban area during heating-period were discussed. XRD and SEM were applied to study the mineral compositions and morphology of the PM10, respectively. It was concluded that concentration of PM10 at nighttime was higher than that at daytime generally. By XRD analysis, it was found that the finer the particles, the less the minerals in it. Furthermore, from the SEM micrograph, five types of the particles, mostly from coal burning and diesel exhaust in number concentration, were classified as chain-like aggregate, cluster aggregate, spherical particle, flake-like particle and non-regular particle.