The Oxygen Monitoring of the Danube River on the Section Oltenita-Black Sea

Danube river basin overlaps great depressions of C entral and SE Europe is the second largest river in Europe and 24 th in the world.The Romanian section represents 29% of the surface area of the whole basin, with 37.7% of the river flowing through its territory. Organic pollution has been increasing in parts of the Danube Basin up till the end of the last century, as industrial production and hous ehold consumption have resulted in increasing loads of wastewater rich in organic matt er.Together with other countries, Romania is part of the transfrrontalier program. The TransN ational Monitoring Network, in short “TNMN” was established to support the implementation of the Danube River Protection Convention in the field of monitoring and assessmen t. In order to monitorize the section Olteni Ńa-Black Sea, in 2008 were taken in study 4 sites, namely: Chiciu, Braila, Tulcea and Sulina. F or this study we have monitored the oxygen represented by: OD, BOD5, CCO-Cr, CCO-Mn, indicators that determine pollution with organic compounds. The methods we used within the European norms and the monitored parameters were analyzed with specialized equipment, like the device for determining the BOD model OxiTop IS 6. In the study the BOD values are higher in the months of spring and summer and indicate the quantity of oxygen required for oxidation the organic materials. Differences between BOD and CCO CCO-Mn-Cr gave us clues on industrial water discharged into emissary. In this study, significan t differences are observed, even two times higher CCO-Cr and CCO-Mn compared to BOD, the water is polluted with organic material from waste water discharged by various industries i n the Danube River tributaries. Dissolved oxygen was determined using Oxigenometrului inoLab730 P, and the values varys depending on atmospheric pressure, water temperature, content of mineral salts, micro-organisms in water. In this case there are no significant differences compared to the maximum allowed. It is recommended the monitoring of the Danube River water quality; the public awareness about the negative effects of anthropogen ic activities on water quality.