Geochemical Characteristics Of PM₁₀ In Handan City, China

With the development of economy, air pollution is increasingly serious in Handan，a mining and industrial city. Smog events have numerously occurred in recent yearswhich seriously jeopardize the health of the residents. PM10,which is becoming themajor pollutant of Handan presently, contains a lot of toxic compounds, such as PAHs,n-alkanes and heavy metals. So the study of PM10has an important practicalsignificance. In this thesis, physical and chemical characteristics and sources of PM10inHandan are preliminarily studied. Samples of the four seasons have been collected inthree tipical residential areas including Hebei University of Engineering, Fengfeng andBaijiacun.Sampler of middle flow capacity is used to collecte PM10samples. Concentrationchanges in different seasons of PM10are winter> autumn> spring> summer bycalculateing in weight method. Soot, minerals and fly ash are the main types of particlesin PM10through FESEM.Organic extraction experiment and GC-MS technique are used to analyse n-alkanesand PAHs. Concentrations of n-alkanes in PM10are18.03~2302.82ng/m3. The values ofCmaxand CPI are used to identify the origin of n-alkane. The results reflect thatanthropogenic sources are the main origin in witer, while anthropogenic sources andnatural sources in autumn, natural sources in spring and summer.11kinds PAHs ofpriority controlled PAHs have been identified from PM10samples in this study. Thetotal concentrations in four seasons from spring to winter are6.60~15.67ng/m3,3.73~26.53ng/m3,21.97~49.01ng/m3and44.33~136.53ng/m3, respectively.Benzo(a)pyrene contents of the samples are0.33~8.82ng/m3, that seriously exceeds thelimits of Ambient Air Quality Standards (GB3095-2012). Ratio method is used toanalyse the source of PAHs in PM10. To the results, coal combustion has been intendedto the main source of PAHs in winter, while vehicle exhaust is the most importantsource in the other seasons.ICP-MS is used to analyse the concentrations of heavy metals in PM10.Concentration characteristic of Mn, Cu, Cd, Pb and Ni is low in summer but high inwinter. Cd and Mn badly exceed, and Pb also has a high concentration. Iron and steelsmelting, vehicle exhaust and coal combustion are the main sources of these heavymetals. According to this study, different degrees of pollution exist in n-alkanes, PAHs andheavy metals of PM10in Handan City, especially in winter. Attentions should be paid toby the relevant departments.