HYDROCHEMICAL ASSESSMENT OF THE WATER QUALITY OF THE RIVER DNIEPER IN THE AREA WHERE UNDERGROUND AND SURFACE WATER DISCHARGE

Abstract

This study assesses the quality of surface water in the River Dnipro in the vicinity of the discharge point from the drainage collector serving a residential area in the Dnipro City. The relevance of the study stems from the regular influx of specific pollutants, namely anionic and non-ionic surfactants, in the drainage effluent from urbanised areas, as well as the need to assess their impact on the condition of water bodies within large industrial cities. Water samples were collected from the drainage collector and from the River Dnipro, upstream of the discharge point. Laboratory analyses were carried out in a certified hydroecological research laboratory using standardised methods: gravimetric, titrimetric, potentiometric, spectrophotometric and others. It was established that most of the parameters studied, namely dry residue, water hardness, chlorides, sodium cations, alkalinity, and pH, in the water from the collector exceed the river’s background values, but do not exceed regulatory limits, which corresponds to the typical chemical composition of groundwater. The levels of surfactants are of critical concern: the concentration of anionic surface-active substances in the collector water is approaching the maximum permissible concentration whilst the concentration of non-ionic surfactants exceeds the permissible limit by more than 50 times in the collector water and by more than 30 times in the river water, indicating active pollution of the water body. The results obtained confirm the need to modernise surface and groundwater drainage systems in densely built-up urban areas and are in line with the priorities of Ukraine’s state environmental policy in the field of water resources protection