Changes in the content of polycyclic aromatic hydrocarbons in tundra peatlands with increasing natural temperatures

Abstract

A model experiment was carried out to assess the temporal changes in the composition of poly cyclic aromatic hydrocarbons extracted from peat samples of the seasonally thawed layer of tundra peatland at the Barents Sea coast under the conditions of the temperature rising to 5 ± 1 °C. The data obtained indicate constant variation in the PAH composition throughout the experiment. Changes in the molar fraction of PAHs can be described by a sinusoidal curve with several maxima and minima. The molar fraction of naphthalene, which dominated in the composition of peat PAHs, changed similarly to the changes in the total content of polyarenes. The total proportion of heavy polyarenes increased regularly throughout the experiment. The presence of extema in the PAH content and recombination of their composition during the experiment is explained by the fact that in the absence of light hydrocarbons readily available for decomposition microorganisms began to decompose heavier structures, or, as their content decreases, more complex organic substances of peat.