Saturday, 15 July 2006

Heavy Metal Contents in the Soils around the Novocherkassk Power Station.

Saglara Mandzhieva1, Tatiana Minkina1, Samokhin Aleksei1, and Olga G. Nasarenko2. (1) Rostov State Univ, B.Sadovaya 105, Rostov-on-Don, Russia, (2) Don Agrarian Univ, Persianovka, Novocherkassk, 344000, Russia

Novocherkassk (Rostov Region, Russia) is among the cities of significant anthropogenic contamination: the annual gross emission of contaminators, especially Heavy Metals (HM), make there 250,000 tons. The Novocherkassk Power Station produces 1% of the emissions across the territory of Russia and more than 50% over the Rostov Region. The aim of the work is to study the heavy metal content in the soils around the Novocherkassk Power Station. The objects of our research were the soils located within the Power Station zone. Field studies have been held since 2001. Sampling was made inclusive of the wind rose passing in the north-west direction, at the monitoring plots fixed on the map and located in different directions and at different distances from the Power Station (within the range of up to 20 km). HM mobile forms were extracted from soil by ammonium acetate buffer solution NH4OAc, pH 4.8. The HM concentrations in plants were determined by dry method. Total and mobile metal contents were analyzed by AAS. The Novocherkassk Power Station causes HM accumulation in the soil, which at times exceeds the maximum concentration limits (MCLs). This refers to such elements as As, Pb, Zn, Cu, Cr. However the character of As and Cr space distribution does not reveal any local contamination sources. The index variation may be due to the regional soils peculiarities, rather than contamination. The excess of Pb, Zn and Cu total concentration of the MCLs is mainly observed in the nearest monitoring plots of the north and north-west directions from the Power Station. Sample contamination with Ni and Mn has not been established. There are no connection between the total content of HM and the mobile forms in soil. This is due to the fact that the HM mobile forms content is much affected by the soil properties. Thus, the excess of the MCLs in Cu and Zn mobile forms can be mainly observed at sandy soils. At the same time almost all monitoring plots were contaminated by Pb and Ni mobile forms. This may be connected by a high content of these metals in the Power Station emission, as well as the impact of the vehicles' waste gas on those roads located closely to the plots. The study of distribution of the HM total concentration and mobile forms in soil profile has shown that they are mostly accumulated in the upper layer, while their maximum can be found in the 0 - 5 cm soil layer. Their content lessened with depth. Comparing the metal contents in soil in the years 2001 - 2005, one can see their rising tendency. Thus, basing the research upon the databank of the ecological situation on the territories around the Novocherkassk Power Station, we have established: o contamination of researching plots by total concentration and mobile forms metals; o the basic sourse of contamination of the researching soils is Novocherkassk Power Station; o the sources of additional emission may also be vehicles waste gas; o HM intensive surface accumulation and their 2 - 5 time reduction within the 5 - 20 cm layer; o dependence between the HM accumulation and location towards the Novocherkassk Power Station, and the additional emission sources, as well as the adsorption soil properties. Acknowledgement: The work was supported by the Russian Foundation for Basic Research (grant 04-04-96804) and the Ministry of Education and Science of Russian Federation.

Back to 2.2B Adsorption Processes in Soils - Basis for Ecological Soil Functions - Poster
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)