Comparative analysis of the level of pollution of the organogenic horizon of Al-Fe-podzols and bog soils in the local impact zone of the copper-nickel plant

On the Kola Peninsula, peat bog soils and Al-Fe-humus podzols (according to the WRB classification, Cryic Ombric Fibric Histosols and Folic/Histic Albic Podzols, respectively) are the most common. However, comparison of their level of pollution with heavy metals (HM) has never been carried out. The purpose of this work is a comparative analysis of the level of HM pollution of the upper horizons of peat bog soils and Al-Fe-humus podzols in the impact zone of the copper-nickel plant. Soil testing was carried out in 37 closely located habitats (forest and swamp) situated in the zone of atmospheric emissions of the Severonickel plant (Murmansk region). The total content of Ni and Cu in soil samples was determined by atomic absorption spectrometry after their dissolution in a mixture of concentrated acids HNO3 and HCl. Statistical analysis of the soil analysis results was carried out in Statistica 12 using nonparametric Kruskel - Wallis, Mann - Whitney and Wilcoxon tests. It was established that both types of studied soils did not significantly differ in the total content of HM in the upper horizons of the soil profile. The level of pollution of compared soils is determined by the distance from the source of pollution, the rose of the prevailing winds and the orography of the terrain. The Ni content in almost all soil samples exceeds the Cu concentration, which is due to the excess of atmospheric emissions of technogenic Ni compounds compared to the content of Cu compounds in them. The phytotoxicity of both types of studied soils varies widely: from its complete absence to a high and very high degree. At the same level of soil pollution with HM swamp habitats are more prosperous due to better moisture content of peat bog soils.