Dissolved Organic Carbon and Biodegradable Dissolved Organic Carbon determination in river water of the Strug basin

The aim of the study was to determine Dissolved Organic Carbon (DOC) and Biodegradable Dissolved Organic Carbon (BDOC) concentrations, as well as the correlation between them, in the river water of the Strug basin located in the Carpathian Foothills. The Strug river's hydrographic basin was chosen for the study as it is a typical catchment area, which allows ease of measurement. DOC concentrations in the streams (tributaries) and the Strug ranged from 2.71 to 4.88 mgC/dm3 and from 3.62 to 4.19 mgC/dm3 , respectively. BDOC concentrations in the streams and the Strug ranged from 0.40 to 1.09 mgC/dm3 and from 0.64 to 0.77 mgC/dm3 , respectively. BDOC, expressed as the percentage of DOC (%BDOC) ranged from 14.76 to 24.78% in the streams, and from 17.68 to 20.11% in the Strug. The procentage of BDOC is independent of DOC concentrations. The season of the year and the size of the watercourse had the greatest impact on DOC and BDOC concentrations.