Sorption Properties of Urban, Forest and Technogenic Soils in Sofia Region

Abstract

Are tested sorption properties of soils from urban, semi-urban and mountainous parts of the Sofia Valley. And have taken samples of Technogenic Soils of metallurgical output of metallurgic plant “Kremikovtzi”. Work is the method of Ganev-Arsova (1980), which are calculated values for total capacity sorption - CEC (T8.2), and values of sorption capacity on the surface of the soil colloids, where the forces of bonding are ionic – specific position (TCA), and also the capacity on top of clay crystal bars where forces bonding are covalent – non specific position (TA). In urbanized soils TCA is higher than 85 percent, which means that the amount of exchange Ca and Mg is high, especially in the surface horizons. Very high values of TCA have Technogenic Soils (> 94.58). In urbanized soils observes also trace amounts of exchange Al, which shows that could not be said of the demolition of kristal structures of clay minerals. In Technogenic Soils do not show an exchange Al. Urbanized soils are saturated with bases and have a high total sorption capacity (T8.2). This is typical also for Technogenic soils. On the natural mountain soils in the region are lower sorption capacity and more often are non saturated with bases. For urbanized soils occurred alkalization the surface horizon compared with below underlying horizons, which is their diagnostic characteristics. On the contrary, in mountain soils from the Sofia region occurred acidification of the surface horizon, which is typical for forest soils in Bulgaria. For Technogenic soils of metallurgical production is characteristic alkalization for the all profile.