Opole University of Technology, Chair of Thermal Engineering and Industrial Facilities, Opole, PL
THE REMOVAL EFFICIENCY OF DUST DURING SHORT-TERM RAINS – VERYFICATION OF ADDITIONAL FACTORS
This paper reports the results of a comparison of the results of field study concerned with the effectiveness of PM10 scavenging by liquid precipitation in a warm and cold season of the year. The aim of this study involved: - verifying if the value of the removal coefficient (C) is relative to the duration of the phenomena of wet deposition, - verification of a hypothesis that the initial value of PM concentration does not affect the value of C PM10. The registration of the variability of PM concentrations was undertaken over the period of seven years in the conditions of the occurrence of convective and large-scale precipitation and it was performed in a non-urbanized area. The analysis involved 344 cases of observation with the constant time interval of 0.5 h. The measurements of PM10 mass concentration was performed with the aid of a reference method accompanied by concurrent registration of the basic meteorological parameters. It was indicated that the value of the removal coefficient assumes similar values in the cold and warm season for all types of precipitation with the mean intensity of R > 0.5 mm h-1. It was additionally noted that the effectiveness of PM10 removing by precipitation with various origin does not statistically vary according to the season. It was indicated that for precipitation with a low intensity, the values of the mass concentration of particulate matter in the ground-level zone could affect the values of the removal coefficient. It was also concluded that the diverse structure of wet deposition with a small intensity plays an important role in the process of the scavenging of solid particulate matter from close-to-ground troposphere.
Keywords: precipitation, PM10, scavenging process, background area