Street Cleaning As PM Control Method

Abstract:

Street cleaning is often proposed as a PM abatement strategy in cities to reduce resuspended road dust contributions to ambient PM10 concentrations. This work presents the results on effects of street cleaning on dust loads of street surfaces and ambient PM concentrations at a heavily trafficked site in Stuttgart Neckartor (Germany). The approach was based on operating a modified mechanical broom and water wash street sweeper equipped with fine dust filter in its hopper along the six lanes paved roadway at the Neckartor site from November 2006 to March 2007. A series of direct dust samplings from street surfaces were performed from mid January 2007 to mid March 2007 in parallel to extensive ambient PM measurements. The results indicated that the street cleaning activities demonstrated favourable sweeping efficiency from 60 to 80 % for reducing the dust loads on street surfaces depending on the particle size group. The direct impact of street cleaning on the dust loads of street surfaces lasted over one rush hour. While reductions in ambient PM concentrations could be suggested during periods when street cleanings were conducted, an exact quantitative evaluation on the effectiveness of street cleaning activities was complicated by the possible influence of local meteorological conditions and other unknown effects. Even though measurement data from two additional reference monitoring stations in Neckartor were evaluated during this period, the frequent natural cleaning processes from precipitation and wind during the street cleaning campaign in winter 2006/2007 made it difficult to accurately assess the street cleaning efficiency on the ambient PM10 concentrations. Therefore, conclusions cannot be drawn at this point, that street cleaning is entirely effective as an emissions reduction strategy for ambient PM10 in cities even for such modified street sweepers. However, the effect of minimising the dust loads on street surfaces could be clearly demonstrated.

Keywords: urban air quality, PM10 abatement strategy, resuspended road dust, street cleaning