Consequences of the impact of some industrial plants on the content of heavy metals in soils

Studies have been carried out to assess the degree of soil pollution in Armenia with heavy metals (HM) near existing (Kajaran Copper-Molybdenum Plant and Hrazdan Cement Plant) and currently not operating (Alaverdi Mining and Metallurgical Plant and Vanadzor Chemical Plant) industrial enterprises. The selection of soil samples was carried out from the plots at a distance of 0.5, 1.5, 2.5, 5, 10, 15 and 25 km from the source of pollution. Analysis of the results of chemical analysis of soils showed that at a distance of up to 5 km from technogenic sources, soils are heavily contaminated with compounds of copper, zinc and lead. As the distance from the pollution source increases to 25 km, a significant decrease in the concentrations of all HMs occurs, and the comparative series is represented by the following sequence: Zn > Cu > Pb > Co > Mo. At a distance of 25 km, a significant decrease in anthropogenic load on the soil is noted. The greatest 50 times decrease in the total HM content was found for soils near the Alaverdi Mining and Metallurgical Combine, and the smallest in the case of the Hrazdan Cement Plant. For the rest of the considered enterprises, the decrease in the value of the coefficient of total pollution was 25 times on the average. The information obtained can be used to take into account the migration and storage capacity of HMs in the soil when organizing environmental measures, depending on the remoteness of the main source of pollution.