Snow-dirt sludge as an indicator of environmental and sedimentation processes in the urban environment

Abstract

The formation of snow-dirt sludge (SDS) via the mixing of snow and surface-deposited sediment by vehicles and pedestrians is one of the least studied sedimentation processes in urban areas. The aim of this study was to analyse the material, mineral, particle size, and chemical compositions of the SDS solid phase. The study was conducted using Ekaterinburg, Russia, as an example city with an intense anthropogenic impact and a long cold snowy period. The average content of the SDS solid phase was approximately 35 g L−1 of meltwater on heavy traffic roads, of which the dust fraction (<0.1 mm) accounted for 23 g L−1. On driveways and lawns, the contents of the SDS solid phase were 12 and 6.6 g L−1, respectively. The mineral composition of the SDS solid phase was generally similar to the geology of the surrounding area, which is composed of a mosaicked combination of felsic and mafic complexes. The presence of building material fragments and other anthropogenic particles confirms the significant anthropogenic impact. The chemical composition contained major and minor elements specific to the minerals and materials that constitute the SDS solid phase. There was significant variability in the concentrations of Pb, Cu, and Zn in the granulometric fractions, indicating pollution. Intensive melting of SDS with a high particulate matter (PM) content is an important factor influencing the environmental quality of the urban environment.

Dissolved and Suspended Forms of Metals and Metalloids in Snow Cover of Megacity: Partitioning and Deposition Rates in Western Moscow

“…Our data on snow cover pollution show an increase in the content of solid particles by almost four times in snow meltwater near roads compared to the yards of residential buildings with car parking lots, which indicates a significant contribution of particles larger than PM 10 to atmospheric deposition, as well as the presence of an additional source of solid particles in snow, e.g., DISs. A sharp increase in the content of particulate matter in snow cover when using DISs was also found in other cities, for example, in Yekaterinburg (Russia); where the content of particulate matter in the snow cover of roads and footpaths is 4-5 times higher than in the snow cover of lawns and car parking lots in the yards [21].…”

“…The predominance of suspended forms of most MMs seems to be typical of urban areas, as supported by the data on Cr, Pb, Cu, Ni, Al, and Fe in snow in Östersund [15] and on Pb, Cu, Zn, and Cd in snow in Luleå and Umeå, Sweden [16]. Concentrations of Al, Fe, Mn, and V in snow cover of the traffic zone increase with increasing particle size reaching the maximum in particles >1000 µm, while the concentrations of Zn and Pb are the highest in particles < 100 µm [21]. This trend is observed even in small cities with no industrial enterprises, where the increasing contributions of 0.45-1.2 µm, 1.2-8 µm, and >8 µm fractions to the total concentrations of these MMs in snow cause lower proportion of dissolved forms of Al, Si, Mn, Fe, and Zn compared to the background territories, as shown by the Valday case study [112].…”

“…In Paris, the contributions of road dust emissions were estimated to be 13% of atmospheric PM 10 , while the sum of vehicle exhaust and wear accounted for 47% of PM 10 [103]. Moreover, for the north cities, the spraying of mud sediment from the surface of roadways is an essential source of suspended particles and MMs in roadside snow cover [21].…”

“…Large amounts of MMs accumulate in snow cover as a result of soil and road dust particles transfer. They are resuspended from the road surface during long snowless periods and from the snow-free areas [4], as well as when cars spray particles of contaminated material accumulated on the road surface and consisting of snow, DISs, dirt from the car wheels, and a large mass of soil particles [21]. Input of a large group of MMs as a result of blowing and splashing mud material from the surface of roads is indicated by the formation of associations of suspended Ni-Al-Mg-Ti-Ca-Sr-Mn-Co-W-K-Rb-Ba-Ni-Fe-V and dissolved Ti-Fe-Pb-Al-Sn-Bi-W.…”

Gross Alpha and Gross Beta Activity Concentrations in Dust Fraction of Urban Surface Deposited Sediment in Russian Cities

“…The samples of USDS were collected from the investigated cities: Ekaterinburg, Nizhny Novgorod and Rostov-on-Don [16]. These cities have a continental climate and are lying in various geographic areas.The investigated cities are described in Table 1.…”