Influence of Sitkówka sewage treatment plant on the Bobrza River water quality

Abstract

The paper presents an analysis of 20 physicochemical elements in the Bobrza River water sampled above and below the treated sewage discharge point. Sitkówka mechanical and biological sewage treatment plant with a value of 289 000 People Equivalent discharges on average 51 000 m 3 of treated sewage daily, which makes up 29% of mean daily flow in the Bobrza River. On the basis of hydrochemical analyses it was stated that the discharge of treated sewage led to worsening of 18 out of 20 studied water quality indices in the Bobrza River. In the river water below the sewage discharge statistically significantly higher values of electrolytic conductivity, dissolved solids, calcium, magnesium, sodium and potassium were registered. A decrease in dissolved oxygen content in the water and increase in its electrolytic conductivity caused a change of water quality class in the Bobrza River from the maximum potential to potential below good. On the other hand, increase in concentrations of dissolved solids and sulphates caused a change of the water class from the maximum potential to good potential. Statistical factor analysis (FA) made possible a reduction of a set of 20 physicochemical elements to four mutually orthogonal factors explaining 95% (above the treatment plant) and 96% (below the treatment plant) of the internal structure of primary data. The first factor is connected with point source pollution (sewage discharge), the second describes oxygen conditions in water, the third results from seasonality and is responsible for the pollutants from natural sources, whereas the fourth factor has not been unanimously defined yet.

Spatial and Seasonal Dynamics of Inorganic Nitrogen and Phosphorous Compounds in an Orchard-Dominated Catchment with Anthropogenic Impacts

“…Each month, the WWTP in Błędów (except February) caused an increase in NH 4 + concentration in the Machnatka River and further on in the Mogielanka River below the confluence. It is also important to mention that lower oxygen saturation and higher PO 4 3− concentration were noted below both wastewater treatment plants, and such influence, usually negative, was broadly discussed in numerous studies [59,62,88].…”

“…Such riparian communities are dominated by species typical for this type of forest in the Central Polish Lowlands [58], such as common alders Alnus glutinosa, marsh marigolds Caltha palustris, and perennial forbs. Although the studied areas are is characterized by a low degree of urbanization (only 3%), in the catchment, several anthropogenic objects exist, which can significantly modify selected chemical water quality parameters of rivers [59][60][61][62][63]. These are mainly weirs, for example, located in Błędów, as well as inflows from municipal wastewater treatment plants in Błędów and Mogielnica (Figure 1).…”

Nutrient Pollutants in Surface Water—Assessing Trends in Drinking Water Resource Quality for a Regional City in Central Europe

“…The decreasing amount of water used by agriculture and forestry in the San catchment indicated a transformation in the land use in the discussed area, which undoubtedly affected the aquatic environment quality. The resulting lower loads of nitrogen and phosphorus supplied to the environment, both from point sources (such as sewage) [14], surface runoffs [18] and precipitations, might have influenced the diminished concentrations of nutrient pollutants in the Wisłok River water.…”

“…From its source to the Besko Reservoir, the Wisłok River is a flysch stream (type 12). From the reservoir to Strzyżów village, it has the character of a small flysch river (type 14) and then passes into a uniform part of type 15-the eastern upland river. The Wisłok River is 204.9 km long with an average channel slope of 3.09‰ and originates from the Kanasiówka mountain (823 m above sea level) in the Beskid Niski Mts., by the border with Slovakia (49°20′59″N 21°57′28″E).…”

Analysis of the Hydraulic Load of a Local WWTP In the South-Eastern Poland Including Hydraulic Capacity of the Sewage Receiver

“…For example, Chen et al [2004] suggest a negative effect of sewage discharge on nitrogen concentration in water of the receiver. Similarly, the unsatisfactory quality of flowing waters of the receiver studied by Kanownik et al [2017] is related to the discharge of treated sewage. On the other hand, studies by Ofman et al [2017] showed that properly treated sewage does not affect the quality of receiving waters.…”