Effects of the alkalization process on the humic substances in Podzols in the vicinity of the fly-ash dumping site of the electric power plant

摘要

The influence of fly-ash dumping site of the electric power plant on the surrounding podzols was investigated. Examined fly-ash indicates pH values above 10, thus due wind erosion adjacent podzol profiles are alkalized, especially their ectohumus horizons. In result, humic substances originally occurring in the Bhs illuvial horizon (present in the control profiles) have been leached out of the soil, and Bhs horizons were transformed into Bs horizons. Alkalization of the soil environment caused changes in humus substances extracted from ectohumus horizons. An increase of N in chemical composition of fulvic and humic acids was observed, and an increase of O/C ratio in humic acids, showing their higher humification degree. Higher values of E2/E6 and E4/E6 ratios confirmed a higher degree of condensation of aromatic structures of affected humic acids. EPR analyses did not indicated new radicals, but observed changes suggest the preference of the following direction: hydrochinon - semichionon - chinon.