Monitoring of the Nitrogen Level in the Hungarian upper Section of the Danube (1848-1766 river km)

Abstract

Monitoring of the nitrogen level is one of the most important issues in assessment of water quality. In the present work the hydrochemical investigation of the nitrogen species (Dissolved Inorganic Nitrogen (DIN) including 4 NH + -N, 2 NO − -N and 3 NO − -N, Dissolved Organic Nitrogen (DON) and Total Dissolved Nitrogen (TDN)) of the Danube River was studied based on the measured chemical data originated from the sampling sections located at Rajka, Medve and Komárom (1848, 1806 and 1766 river km) under the authority of the Inspectorate for Environment, Nature and Water of the North Transdanubian Region (Hungary). The quantitative changes of the nitrogen species were examined as a function of time and longitudinal section in the period of 1989-2008. The results have revealed that the DIN has been slowly decreased in the Hungarian upper section of the Danube in the long run. In the last two decades the concentration of the ammonium has decreased significantly while the amount of nitrate and nitrite has decreased only by a smaller extent. The concentration of the DON and TDN decreased in the second half of the examined period.