eutrophication

The influence of Prague on water quality in the Vltava and the Czech Elbe

This paper deals with the development of water quality in the Elbe in the section between its confluence with the Vltava and the Hřensko border profile in 1980–2020, and with the influence of Prague on its pollution levels. After a significant improvement in 1985–2000, the quality of water discharged through the Hřensko profile today is at least at the level of the Federal Republic of Germany. Evaluation of substance transport shows that the Vltava contributes a larger share of pollution to the Elbe simply because it has higher flows. Prague contributes to pollution of the Vltava and the Elbe by discharging phosphorus.
As for other long-term indicators, it is an insignificant source.
In 2010–2020, there is a significant level of concentrations of pharmaceuticals, which come exclusively from the discharge of municipal wastewater treatment plants (WWTP). Many pharmaceuticals regularly occur in concentrations of tens to hundreds of [ng/l], and resistant pharma-ceuticals (gabapentin, metformin, oxipurinol, carbamazepine) are transported to Prague from the Vltava basin through the Orlík and Slapy reservoirs with a high theoretical retention time. The transport of resistant pharmaceuticals through relevant profiles corresponds mainly to the number of inhabitants in their river basins because they obviously pass through WWTP and do not degrade further in the river either.

Fishponds in Hracholusky Reservoir drainage basin – results from screening

Series of 16 fishponds was monitored as a part of a drainage basin of Hracholusky reservoir, which is subject of a recovery project. All the fishponds were eutrophic – hypertrophic due to wastewaters from villages and little cities (including overflows from sewers) and/or due to too intensive production of “hunters ducks” – the phenomenon that is rarely mentioned.

The impact of oxygen and nitrates availability on phosphorus cycle in sediments – an example of the Vranov Reservoir

The inflow parts of eutrophic reservoirs typically exhibit exacerbated rates of primary production, with concomitant increase in organic matter sedimentation. Its microbial remineralization leads to the consumption of electron acceptors.