This study investigated the possibility of using artificial neural networks to predict changes in the concentration of chloride ions in the urban ponds on the example of the inflow and outflow zones of water to and from the ponds Syrenie Stawy in Szczecin (NW-Poland). The possibility of using selected water quality indices (selected based on correlation matrix of water quality indices with Cl−), in particular: COD-Cr, BOD5, DO, water saturation by O2 and NO2− and their influence on the chloride concentration forecast was tested.
Gorzysław Poleszczuk, Tymoteusz Miller and Małgorzata Tokarz
The possibility of using - to a wider inference - water quality test results of stream Osowka flowing through ponds Syrenie Stawy in Szczecin (NW-Poland) - in particular the concentration of dissolved oxygen (DO), electrical conductivity (EC) and the total concentrations of nitrogen (TN) and phosphorus (TP) - conducted in the years 1994 to 2014 was analyzed. The examined indices were classified according to Official Standards currently in force in Poland. Changes of water quality as it flows through the ponds were identified. Multivariate linear regression equations were calculated, endearing statistically significant relationship between successive test indicators (yi) and other indices (xi) and deadlines for measurement periods (Ti) has been made. This allowed in general to characterize water quality, determine the quality changes along the path of flow through ponds and discern what processes biohydrogeochemical within the ecosystem changes affected their quality.
Gorzysław Poleszczuk, Anna Bucior, Tymoteusz Miller and Małgorzata Tokarz
In the vegetation season April-October 2010, the value of and the changes in Zntot., Cutot., Cdtot. and Pbtot. concentrations in the water of the Rusalka flow-through lake (with average water retention of ca 30 days) situated in the city centre of Szczecin were determined. Water temperature, pH, concentration of dissolved oxygen (with calculation of water saturation with O2), COD-Cr and BOD5, total hardness, - 3 HCO concentration (as total alkalinity), Cl-, - 24 SO , Mntot and Fetot were also determined. The data collected may be used to evaluate the ecological and chemical status of the surface waters under investigation. As far as the ecological status of the Rusalka Lake is concerned, the investigated waters were found, based on the official criteria being in force in Poland in evaluation of the ecological and chemical status of surface waters, to conform to water quality classes I and II considering total zinc and copper concentrations, temperature and dissolved oxygen concentration (except water inflow to the lake in August) as well as BOD5, - 24 SO and Cl- concentrations and pH value; however, they were always worse than water quality class II while taking the COD-Cr values into account. Regarding the chemical status of the investigated waters, total cadmium and lead concentrations were the levels exceeding the admissible values according to the official criteria in Poland. Changes in the values of indices being investigated along water flow path allowed stating that the equilibriums between the sedimentation and the resuspension and the dissolution processes during the research period were shifted towards sedimentation in case of Zn and Cd only, as well as of the organic matter sedimenting in the form of divalent cation- and divalent anion-sorbing gels. Although three phytoplankton blooms occurred in the body of water, unfortunately weak ones, the dissimilation processes prevailed over assimilation.
Gorzysław Poleszczuk, Zdeňka Svobodová, Anna Bucior-Kwaczyńska and Tymoteusz Miller
After presentation of the characteristics of a water reservoir in CaCO3 excavation pit, called the Turkusowe Lake, situated in the Wolin National Park on the Wolin Island, available results of the analyses referring to the quality of surface water of this water reservoir and being carried out since 1986 as well as those of own studies being carried out from 1999 to 2010 were gathered, collecting this way a research material covering the quarter-century 1986-2010. It was shown that the Turkusowe Lake is a water reservoir being resistant by nature to eutrophication (lake basin development and depth, surrounding by the heights adhering to it, and presence of CaCO3 building the lake basin), whereas an increase in the trophic level and development of eutrophication phenomena in the form of weak phytoplankton blooms being observed, particularly in 2005-2010, is connected with increased anthropogenic pressure in the form of direct discharge of municipal sewage to the lake and waste-water to the soil in the alimentation zone of underground waters feeding this lake. The extent of anthropogenic pressure was so big that it started to prevail over the natural processes limiting an increase in the trophic level in this lake.
Tymoteusz Miller, Zdenka Svobodova, Edward Meller and Gorzysław Poleszczuk
Water quality of the Glebokie Lake in Szczecin (NW-Poland) was studied in years 2012-2014. Glebokie Lake is a reservoir with a negative water balance related to the location draining groundwater drinking water intake for Szczecin agglomeration. In 2004 hydrotechnical regulations were conducted aimed at maintaining a constant amount of water in the lake, which involved a temporary feeding Glebokie Lake with Gunica River waters. In order to determine the hydrochemical status of the Lake waters and the factors shaping water quality - 19 water quality indices within 25 months were measured: temperature, pH and water oxygen status, nutrients (N, P) and ionic macrocomponents and Fetot. Trophic status of the lake waters using the Carlson criteria was defined. On the basis of chemometric analysis of measurement data (CA, PCA/FA and DA) we established that statistically significant factors affecting water quality in the study period were: seasonal (the climatic seasons) changes in the biological processes activity, periodical (in April and November) waters inflows from the Gunica River, anthropopressure in during swimming season and the coagulant (FeSO4) presence in the ecosystem. The possibility of applying the chemometric techniques to interpret measurement data in the lake type like Glebokie Lake with a small amount of data has been shown.