Urban soils in Timisoara city [articol]

Abstract

Urban soils is a term with no very precise definition, used to designate soils of areas covered with streets and buildings or occupied by parks, gardens, recreation areas, sport grounds and industrial production activities. The original soil of such areas has been strongly modified or even completely removed or replaced with other materials. In the Romanian Soil Taxonomy System (S.R.T.S-2012), “Urban Soils” are included in the Class “Antrisols”, as soil types – Tehnosol and Antrosol. Because of their diversified origin, urban soils may contain pollutants in special heavy metals, like Pb, Cd, Ni, Zn. In the suburban area, the main soil types are Chernozems, in the N-NW part of Timisoara, Cambisols and Fluvisols, in the central part of Timisoara and Vertisols in the south part of the periurban zone. The greatest content of heavy metals of the parks are in the “Cathedral Park” and “Justice Park”, with 1,63-1,77 ppm Cd, and 105-132 ppm Pb. Heavy metals tend to accumulate, also, in garden soils, and in general their concentration is on average twice that in agricultural soils, probably because of the input of various amendments and pesticides. The use at burning of the inferior fuel inside the thermo-electric power station (CET), as well as the powders dissipated from the waste dumps loaded with heavy metals, has a great impact upon soils, waters and vegetation (cultivated and spontaneous). Heavy metals are found except a few cases, in the interval that don’t indicate a risk of pollution, above the “admissible limit”.