Environmental Assessment of the Surface Water Quality of the Prudnik River

Abstract

Due to the intensive anthropogenic load on river basins, gradual deterioration of their quality is observed. Small rivers are particularly vulnerable. There is a decrease in indicators that characterize the composition and properties of water, as well as its suitability for specific purposes. From an ecological point of view, water is the living environment of aquatic organisms. Along with this, water quality can be considered in the context of meeting the needs of various sectors of water consumption and water use. Therefore, the study of the quality of water bodies is relevant.
The study is based on the determination of certain characteristics of classes and categories of water quality according to the ‘Methods of environmental assessment of surface water quality by relevant categories’. Ecological assessment of water quality in the Prudnik River is determined tentatively and thoroughly. Approximate assessment is performed by one-time measurements of individual water indicators, which more accurately describe the ecological status of a water body or part thereof and the corresponding water quality: dissolved oxygen content, mineralization, biochemical oxygen consumption, concentration of nutrients, organic matter, heavy metals. The procedure for performing a thorough environmental assessment of surface water quality consists of five successive stages: processing and grouping of source data; determination of classes and categories of water quality by individual indicators; generalization of classes and categories of water quality by separate groups of indicators; generalization of water quality ssessments by indicators for individual blocks with determination of block values of water quality classes and categories; determination of the joint ecological assessment of water quality for a certain water body as a whole or its separate areas for a certain period of observations.
The ecological assessment of the state of surface waters of the Prudnik River above and below the water treatment facilities of the town of Rozhysche for the period of 2014–2019 was carried out. The structuring of the data of the main statistical characteristics for the studied chemical parameters of water in the targets was performed. The dynamics of physico-chemical parameters of the riverbed was analyzed. A comparative analysis of the concentration of the components of the salt composition of water in the approved targets was performed. The influence of natural and anthropogenic factors on the formation of chemical composition and surface water quality is determined and investigated.
According to the results of the study, the largest excesses of the maximum concentration limit norms for fish ponds were recorded for the content of dissolved oxygen, BSC5, HSC, ammonium salt and nitrites, nitrite nitrogen, ammonium nitrogen, total nitrogen, phosphates, total iron. According to the pollution coefficient, the Prudnik River belongs to the ‘slightly polluted’. According to the indicators of the complex ecological index, the condition of the Prudnik River is characterized ‘excellent’ to ‘good’, and the degree of purity, ‘very clean’ to ‘pure’.