Pollution of Kvemo Kartli Region (Georgia) Soils by Heavy Metals
Authors: Lali Shavliashvili, Elina Bakradze, Elizbar Elizbarashvili, Ekaterina Shubladze, Gulchina Kuchava
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The expedition works were held in the territory of the Madneuli enterprise of Kvemo Kartli region in 2020, where brown soils are spread. In order to study the migration of heavy metals in the soil, taking into consideration the wind direction, the samples of soil was taken from 0-100 (0-10, 10-20, 20-40, 40-60, 60-80, 80-100) cm depths, in North from the source of pollution direction (Background) – weak winds direction, 500 m from the enterprise and in the direction of a strong wind in the West and 300 m from the enterprise. In the soil samples were determined general forms of heavy metals Cu, Zn, Pb, Mn, Ni, Cd, Co, As, Ag, Cr, Fe by Plasma-emission spectrometer at ICP-OES.
The quality of some heavy metal contamination of soil is revealed in connection with Clark; In contaminated areas, the relatively high concentrations of heavy metals are observed in the upper layers, which are due to the prevailing winds. in the samples taken from the north (background-weakest wind direction) heavy metal content were less. Specifically, from the background and contaminated areas the copper content with 0-10 cm layer 63.22 (1.4) and 324.13 (6.9) mg/kg; 80-100 cm depth decreases copper content and is 22.15 and 156.17 (3.3) mg/kg. Similar situation is in case of zinc.
Migration of heavy metals is reduced by increasing depth and approximately 1-5 times exceeding the relevant background importance.
In the samples taken from the background areas, some metals (cadmium, arsenic and silver) are high content, which is due to their existence in the soils of the region. At the same time, it is noteworthy that their Clark indicator is low and therefore 0.13; 1.7 and 0.07, which leads to increasing the Ratio concentration of these metals in relation to Clark.
As it appears from the data, the soil meets in the categories of copper, zinc and arsenic in the category of slightest pollution (<10) category; In cadmium and silver cases – in average pollution (10-30); And the concentrations of lead, manganese, nickel, cobalt and chromium do not exceed Clark.
Correlation links are investigated between the concentrations of different metals in the upper layers of the soil. The correlation coefficient is the largest between Cu and Zn concentrations. It is positive and equals 0.77, determination Coefficient (R2) is 0.58 among the Cu-Zn concentrations. Correlation coefficient between Cu and Co concentrations are 0,62, determination coefficient of Cu-Co concentrations is 0.38. In all other cases the correlation coefficient is negligible and can be neglected.