First International Conference on MOLDAVIAN RISKS – FROM ...

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE
16-19 May 2012, Bacau, Romania
STUDY REGARDING THE INFLUENCE OF NUTRIENTS
OVER THE WATER OF BISTRITA RIVER, ON THE HIGHLY
MODIFIED SECTOR BETWEEN PIATRA NEAMT AND
BACAU
Dan Dascalita 1 , Greta Ardeleanu 2
1 “Vasile Alecsandri” University of Bacau, Department of the Environment Engineering and
Mechanical Engineering
2 Administration of Siret Basinal Water
Corresponding author: Dan Dascalita, dan_dsclt@yahoo.com
Abstract: Industrial activities and human congestions produce significant quantities of
specific pollutants, which, unless highly purified, get into surface water resources and
influence their quality. When the quantity of pollutants exceed some limits, the natural self
defence procedures can no longer take place and the underwater and terrestrial
environment are affected for a long and very long term. In this paper we studied the
evolution of the quality of water in Bistrita River, on the Piatra Neamt – Bacau segment.
This river sector is totally regulated and along it are several hydro-electrical plants that
produce electrical energy. These set-ups, created after the 1960’s, modified the
configuration of the old riverbed. Both the longitudinal and the transversal connectivity of
the natural river course were affected. The permanent flow regime of the river underwent
important changes, due to the special, discontinuous water treatments on hydro-electrical
channels, placed parallel to the natural riverbed of Bistrita River. A negative influence over
the quality of water in Bistrita River, upstream Piatra Neamt and the chemical platform in
Savinesti, is the evacuation of nutrients in high quantities. This negative influence
correlated with the discontinuous water treatment in hydro-electrical plants. In time, this
led to an imbalance of the underwater environment, which recovers extremely slow. In this
paper, we also presented the results of several studies concerning the influence of nutrients
over the quality of water in Bistrita River, on the specific sector between 1990 and 2000,
taking into account that the sector is hydro-morphologically affected by the hydroelectrical
plants. In our study, it can be seen that in the last years the quantities of
pollutants evacuated in Bistrita River on this segment have dropped, as a result of rigorous
controls from water management authorities, and of advanced treatment of nutrients at
tertiary purification levels. The discontinuous water treatment in hydro-electrical plants
between Piatra Neamt and Bacau still influence the quality of water in Bistrita River, by
not providing adequate dilution volumes. These negative influences are obvious during
periods when affluent natural debits are smaller than multiannual debits. In this study we
used a complex data base from the Administration of Siret Basinal Water archive and our
own experience in this area..
Key words: nutrients, hydro-technical arrangements, highly modified surface water body.
100