PROPERTIES OF ORGANIC MATTER IN CHOSEN SOILS FERTILIZED WITH SEWAGE SLUDGE

The properties of organic matter from Dystric Arenosols and Stagnic Luvisol fertilized with sewage sludge produced in biological-chemical treatment plants have been examined. Organic matter (fractions: post-decalcination, bitumins, fulvic acids, humic acids, humines) has been fractionated and humic acid properties (elemental composition, UV, VIS, FT IR spectra) have been determined. Organic matter from the soils has been characterized by similar per cent of carbon and nitrogen and a similar humification level in the separated fractions. The most humified and matured acids (i.e. with higher proportion of aromatic groups, lower content of aliphatic side-chains, and higher condensation of aromatic rings) have been found in Stagnic Luvisol.