IMPORTANCE OF OXYGEN REGIME INDICATORS – CASE STUDY OF THE NIŠAVA RIVER IN SERBIA

Abstract

From a global perspective, there is currently an ever-increasing problem of natural water resource pollution and daily decrease of available amounts of potable water. In addition to the definition of their ecological status, the existing problems of polluted water systems also require that parameters of the oxygen regime should be determined. The importance of monitoring the indicators of oxygen regime in rivers is aimed at achieving sustainable water management and preserving environmental quality. Oxygen regime in the Nišava river ecosystem is monitored based on specific physico-chemical indicators: biological oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), dissolved oxygen and oxygen saturation. The aim of this paper is to demonstrate the significance of oxygen regime indicators by monitoring their concentrations at measuring stations along the Nišava, which can help assess the quality of the given aquatic ecosystem. The paper relies on the Results of Surface and Ground Water Quality Testing by the Environmental Protection Agency, Ministry of Agriculture and Environmental Protection of the Republic of Serbia for two measuring stations along the Nišava in 2013. Mean annual concentrations of oxygen regime indicators for 2013 are BOD = 2.6 mg/L and COD = 4.3 mg/L, which indicates that the value of their respective ratio is 0.6, which is important for oxygen regime. A comparative analysis performed by the water supply PUC “Naissus”, based on the values of these environmental indicators, also confirmed that water quality in the Nišava corresponds to Class II surface water. Therefore, this paper highlights the importance of monitoring oxygen regime indicators of the Nišava River for the purpose of sustainable water management and environmental quality preservation.