Water Quality of the River Sava at the Inflow of a Pulp and Paper Mill Effluent

Abstract

The results of investigations into the effects of wastewaters from pulp and paper production on the River Sava are presented in this paper. Two situations were studied, i.e., when the treatment plant was in operation and when it was not working. The results of the investigations indicated that the wastewaters had significant effects on the Sava. Chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were increased and some toxic substances were present at high concentrations, e.g., phenols, oils and grease, dyestuff, etc. The negative influence of the wastewaters was greater during the summer, at low water levels in the Sava. The Sava is a tributary of the River Danube, into which the pollution from this river finally flows. Regardless of the water flow rates, toxic substances are constantly accumulating, and, as a result, even such large systems as the Danube and the Sava are becoming more and more polluted.