Technical Reports Parts C,D - ICPDR

42 Danube Pollution Reduction Programme – National Review, Ukraine
4.11. Water Quality
Data on water quality for Danube River and its major tributaries are presented in the ANNEXES.
Completeness and duration of observations are presented in Annexes.
4.11.1.Nitrogen
Monitoring data are presented only for mineral species of nitrogen meanwhile the total nitrogen
content including mineral and organic species have not been analyzed. Average annual
concentration of the mineral species of nitrogen (sum of mineral species) in the Danube water
varied between 1,39 and 0,51 mg/L with maximal concentrations 2,8 mg/L (Vylkovo and Izmail,
1996). By the monitoring data of the State Ecological Inspection the annual average nitrogen
content was 9 mg/L mostly as nitrates (Fig. 4.9.).
Figure 4.9.
9
Total nitrogenic forms variation (1994-1997)
7
5
3
Reni
Vilkovo
1
Con 1993 1994 1995 1996 1997
Year
The distribution of mineral nitrogen species is presented on the Fig. 4.10. It is evident that the
portion pf ammonium and nitrites decreased significantly during last three years. The highest
concentrations of nitrates were recorded in 1994 and 1995 reaching 13 - 14mg/L. Usually the
highest nitrogen content is accompanied by high water discharges.
Figure 4.10.
Nitrogen mineral forms distribution
(%)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1993 1994 1995 1996 1997
Year
NO2
NH4
NO3