Study on the Assessment of the Oxygen Regime and the Nutrients Content of Some Water Streams in Gorj County

Abstract

The study aims to characterize the quality of some representative surface waters of Gorj county�s hydrographic network by assessing the oxygen regime, namely the dissolved oxygen content (DO), the chemical oxygen demand (COD-Cr), the biochemical consumption of oxygen BOD5) and nutrients measured by ammonium (N-NH4+), nitrites (N-NO2-), nitrates (N-NO3-), total nitrogen, soluble orthophosphates (P-PO43-) and total phosphorus during 2016-2018. In order to carry out the study, representative sections of the Jiu, Motru and Jilt rivers were monitored in areas considered vulnerable to nutrient and organic pollution. The results regarding water quality from the monitored natural receptors generally showed an evolution within the limits allowed by the environmental legislation, except for the nitrite content that was exceeded for all three monitored rivers. Also, the values of the COD-Cr and BOD5 indicators have been exceeded in some Jiu and Jilt river monitoring sections. Consequently, there is a need to monitor the mentioned parameters.