Opole University of Technology, Chair of Thermal Engineering and Industrial Facilities, Opole, PL
COMPARISON OF PM10 WASHOUT ON URBAN AND RURAL AREAS
This paper reports the results of research into the effectiveness of scavenging of PM10, resulting from the occurrence of solid and liquid hydrometeors. The measurement campaign was undertaken over 7 years and involved the registration of PM10 in areas which have different aerosanitary conditions (i.e. urban and undeveloped rural area). The analysis involved 426 observations taken at constant time intervals of 0.5 hour. The measurements of the concentration of PM10 were performed by means of a reference method accompanied by concurrent registration of basic meteorological parameters. It was indicated that in a urban location, the intensity of the local emission sources is a principal factor influencing the value of mass concentration changes (ΔC) and the effectiveness of the dust scavenging that accompanies a given type of precipitation. It was also noted that for the same intensity of precipitation, only the deposition of convective rainfall and long-term large-scale precipitation do not lead to statistically relevant differences in the value of ΔC for both areas. It was indicated that during solid and liquid frontal precipitation of light intensity (< 0.5 mm·h-1), the effectiveness of PM10 removing is less in rural area. It was statistically proven that continuous precipitation of constant intensity and duration exceeding 2 hours has a similar effect of purifying the ambient air in both locations. The study revealed that short-term solid precipitation provides better characteristics of scavenging of PM10 compared with classic rainfall.
Keywords: dust, snow, rain, removal coefficient