Next Article in Journal
Geochemical Characterization of the Eocene Coal-Bearing Source Rocks, Xihu Sag, East China Sea Shelf Basin, China: Implications for Origin and Depositional Environment of Organic Matter and Hydrocarbon Potential
Next Article in Special Issue
Adsorbed Chemical Elements of River Runoff of Solids and Their Role in the Transformation of Dissolved Matter Runoff into the Ocean
Previous Article in Journal
Interaction of Corroding Iron with Eight Bentonites in the Alternative Buffer Materials Field Experiment (ABM2)
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Minerals
Volume 11
Issue 8
10.3390/min11080908
minerals-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Geochemical State of Wilga River Environment in Kraków (Poland)—Historical Aspects and Existing Issues

by
Magdalena Strzebońska
and
Anna Kostka
*
Department of Environmental Protection, Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland
*
Author to whom correspondence should be addressed.
Minerals 2021, 11(8), 908; https://doi.org/10.3390/min11080908
Submission received: 17 June 2021 / Revised: 11 August 2021 / Accepted: 18 August 2021 / Published: 22 August 2021
(This article belongs to the Special Issue Mineralogy and Geochemistry of Suspended Particulate Matters in Rivers)
Browse Figures
Versions Notes

Abstract

:
Aquatic systems are a very important part of the environment, which requires special attention due to the constant deterioration of the quality and quantity of water globally. Aquatic environments in Poland are mostly affected by the mining and smelting industry, which is especially visible in the south of the country, and one of such anthropogenically affected rivers is the Wilga—a small tributary of the Vistula River (the biggest river in Poland). For many years, the catchment area of the Wilga River accommodated a functioning industry that was based on the use of metals (fur, leather processing, foundry and galvanizing plants), as well as the “Solvay” Kraków Soda Works, which have left behind soda waste piles, and currently, along the course of the river, there are ongoing works connected with the construction of the “Łagiewnicka Route”, which required the relocation of a section of the Wilga river bed, among other things. To determine the general condition of the river, selected physico-chemical parameters were analysed in the water (pH, conductivity, anions: Cl−, N-NO3, P-PO4 and SO4 and cations: Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr and Zn), suspended particulate matter and sediment (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr and Zn). Samples were taken before the relocation of the river bed (2019) and after its relocation (2021). The obtained data were compared with recorded historical data and this revealed that over the years, the condition of the Wilga environment has improved significantly, especially in terms of the contamination of sediments with metals, the concentrations of which fell several ten-fold. This is attributed to the closure of most industrial plants located within the river’s catchment area and to the modernization and legal regulation of the functioning of the remaining plants. An effect of leachates from the soda waste piles on the waters of Wilga has been observed (in the form of higher pH, mineralization and concentration of chlorides), which has however gradually decreased over time. However, no visible impact of road transport on the river’s environment has been observed, or any impact of the construction works or the related relocation of the river bed for that matter. The river should still be classified as polluted, but the level of this pollution has decreased significantly and the qualitative composition of the pollution has also changed.

1. Introduction

Aquatic systems are a very important element of the environment, as they provide the habitat for biological life, represent a water source for humans, but also function as a collector of various contaminants and pollutants, derived e.g., from wastewater discharge, fossil fuel combustion or atmospheric deposition, generally connected with growing urbanization and industrialization [1,2]. The deterioration of water quality and quantity is a worldwide problem that concerns not only the developing but also the developed areas of the Earth [3], including European countries [4,5,6], e.g., Spain [7], Portugal [8], Malta [9] and Poland [10,11,12]. Both the quality and quantity of water resources in Poland are relatively poor when compared to other countries in Europe and the European Union. Surface waters in Poland are anthropogenically affected mainly due to wastewater discharge, agriculture, urbanization and industry, especially mining, concentrated mostly in the southern areas of the country [13]. Poland is also struggling with droughts (the most extensive in recent years occurred in 1992–1993, 2006, 2008, 2012 and 2015 [14]) and floods (the biggest ones in recent years took place in 1997 [15,16,17], 2001 [18] and 2010 [19,20]), resulted from gradual climate changes, but also poor water resource management [21] and human economic activity, like regulation of river channels and changes in land use [22,23].
One of the most important roles in water environments is performed by sediments, as they are usually the main collector of contaminants and pollutants introduced into water systems—substances dissolved in water are bonded on the solid particles over time and finally trapped in bottom deposits [24]. Aquatic sediments are also a very dynamic component, in which physico-chemical processes such as transport, diagenesis, bioturbation, remobilization or bioaccumulation, constantly take place [25]. The physico-chemical composition of river sediments in non-industrialised areas depends mainly on the geological structure of the catchment, the dynamics of weathering processes, the morphological structure of the river bed and on the surrounding vegetation [26,27], while in the case of densely populated, urbanised or industrialised catchments, the chemical composition of river sediments reflects the local anthropopressure [28], which may lead to the contamination or pollution of sediments with various substances. Contamination is understood as the increased concentration level of a given chemical in relation to the geochemical background, while pollution means that this concentration poses a threat to biota [24,29]. A distinct, and quite complicated issue, is the appropriate determination of the geochemical background used in environmental risk assessment [30], which may significantly affect the data analysis results [31].
One of the interesting contaminants/pollutants found in water environments are metals due to their non-biodegradability, environmental persistence and a tendency for bioaccumulation [32,33]. Those that are the most frequently examined are: Cd, Cr, Cu, Hg, Ni, Pb, Sn and Zn, as they are potentially toxic, known to be affected by human activity and well documented [34]. The geological structure of Poland and the ensuing location of the main industrial centres (especially in such sectors as mining, metallurgy or power engineering) in the south of the country, has resulted in the contamination or pollution with metals of two biggest Polish rivers (mainly their upper sections)—Vistula and Oder [35,36,37,38,39,40], as well as many smaller rivers and streams located in southern Poland [41,42,43,44,45,46,47,48,49,50,51,52,53,54]. Economic and social changes in Poland have resulted in the termination or reduction of mining activity in many areas, and although a significant improvement in the condition of the affected aquatic environment could be observed quite rapidly (within a few years), it must be noted that the rate and the level of positive changes depend on many variables [55].
One of the rivers strongly affected by human activity is Wilga [56,57,58], which mostly runs through the territory of Kraków (the second biggest city in Poland, after the capital city of Warsaw). This river flows through the construction site of the biggest road construction project in recent years in Kraków—the “Łagiewnicka Route” (pol. Trasa Łagiewnicka S.A. [59]) and through the eastern part of the post-industrial area of the former “Solvay” Kraków Soda Works [60]. This factory began its operations in 1906 and was closed in 1989–1996 due to its strong negative impact on the environment. The Solvay technology of soda ash production requires large amounts of raw materials: sodium chloride (NaCl), limestone (CaCO3), ammonia (NH3) and large quantities of energy [61]. The soda industry also generates large amounts of solid and liquid waste. In the investigated area it was found that post-soda waste, mainly sludge, was deposited in sludge ponds in the amount of a total of 5 million tons across an area of 100 ha [62]. Post-production slurries contain large amounts of inorganic chlorides, carbonates, sulphates, alkali, ammonia, suspended solids and metals [61,63]. Additionally, fur, tanning, foundry and electroplating plants have been operating for many years near the Wilga River, the technologies of which are based on metals. Most of them have already closed down due to their harmful effect on the environment and/or due to social and economical changes, and those that are still operational have been restructured. However, a large amount of contaminants and pollutants from heaps, wild dumps and sewage discharge still find their way into the river [57].
In view of all of the above, the main purpose of the article was to investigate the current condition of the Wilga River environment, with the consideration of the historical pollution, the existing dangers, connected mainly with the construction of the “Łagiewnicka Route” and the related relocation of the river bed, as well as the impact of the nearby soda waste piles and other sources of contaminants and pollutants. Wilga is a tributary of Vistula River, which flows directly into the Baltic Sea, and it has been demonstrated that Wilga is a significant source of contamination found in this biggest river in Poland [56,57,58]. This makes it a global issue, due to the relatively poor chemoecological state of the Baltic Sea environment [64,65,66].

2. Materials and Methods

2.1. Study Area and Sampling

The Wilga River is a small, right-bank tributary of Vistula (the biggest river in Poland) and its source is located in the village of Raciborsko-Pawlikowice (several kilometres from Kraków). The total length of the river is 26.7 km, of which approximately one half runs within the administrative boundaries of Kraków, while its entrance into the Vistula River is situated close to the city centre (Figure 1). In its upper course, the river has a “wild” and meandering character, whereas within the boundaries of Kraków it is regulated and strengthened with backwater embankments [57,60]. Wilga is a submountain river with an average discharge of 0.93–1.35 m3/s and the presence of two discharge peaks: Spring and Summer peaks and one Autumn/Winter low [23,67]. The river catchment of the area of about 100 km2 is mostly used for agriculture, except for the part located within Kraków. The area of the river basin is made of Tertiary claystone and Quaternary sands, and the river banks are quite densely populated with trees and bushes. Wilga does not pose a serious flooding risk for Kraków [10,68].
The area which the Wilga runs through is currently affected by works connected with the construction of a section of the third ringway of Kraków, the “Łagiewnicka Route”, which required the relocation of a section of the river bed of the length of approx. 550 m (Figure 1 and Figure 2), which was done on 29 February 2020. The new river bed was also designed to provide more protection against flooding [59]. The Wilga also runs across the area of the former “Solvay” Kraków Soda Works, which contains soda waste piles that have been partially recultivated and redeveloped [69] (Figure 1 and Figure 3). Moreover, the Wilga basin was heavily affected for several decades by the chemical industry, being a source of toxic elements, among others. The most significant object in the Wilga River catchment area was the Kraków Tannery (pol. Krakowskie Zakłady Garbarskie). Its history started in 1885, when the Dłużyński brothers began production at a facility named (pol.) “Bracia Dłużyńscy, Garbarnia Ludwinów przy Krakowie”, and ended in 1990 when the old departments located in the city centre (Ludwinów) were closed down in view of environmental protection. That year saw the completion of the construction of the plant in Bieżanów, where the production of all departments of the Kraków Tannery were relocated. Modern production halls, a sewage treatment plant and an office building were built on an area of approx. 16 ha [70]. The remaining industrial facilities located in the Wilga catchment area are: Kraków Fur Processing Plant (pol. Krakowskie Zakłady Futrzarskie), active in the years 1951–1974; Kraków Metal Hardware Plant “Metaloplast” (pol. Wytwórnia Galanterii Metalowej “Metaloplast”), active in years 1951–1976 and the previously-mentioned “Solvay” Kraków Soda Works (pol. Krakowskie Zakłady Sodowe), active in years 1906–1996 (Figure 1). Waste generated during the process of obtaining sodium carbonate using the Solvay method (Figure 3), consists of CaCO3 (approx. 70% of dry mass), NaCl, CaCl2, CaSO4, MgSO4, BaSO4, P2O5 and SiO2 [67].
To capture the potential impact of the relocation of the Wilga bed on its geochemical state, the river was sampled twice: before (2019) and after (2021) relocation. 11 sampling points for the extraction of bottom sediment, suspended particulate matter (SPM) and river water, have been established between the border of the city of Krakow (No. 1) and the entrance to the Vistula (No. 11, Figure 1), in characteristic locations along the route of the river bed. Samples of water, from which suspended particulate matter was extracted, were taken in 2019 in four different locations: No. 1—in the vicinity of the city border, No. 5—upstream the construction of the “Łagiewnicka Route”, No. 7—downstream the construction of the “Łagiewnicka Route” and No. 11—in the vicinity of the entrance of Wilga into the Vistula.

2.2. Water Samples Analysis

The physical parameters of Wilga water such as pH and conductivity were determined in the river in situ, using a portable multiparameter meter (model Orion Star A329 by Thermo Scientific, Waltham, MA, USA), in accordance with the ISO 10523 [71] and ISO 7888 [72] protocols, respectively. Water samples were collected into 250 mL glass vessels, for the purpose of cation (with acidification with 10 μL of concentrated HNO3) and anion (without acidification) content definition. The samples were transported to the laboratory, filtered using 0.45 µm membrane filters and stored at 4 °C for further analysis. The concentrations of nitrate-nitrogen (N-NO3) and phosphate-phosphorus (P-PO4) were determined via the spectrometric method, using spectrophotometer UV-Vis (model M501 by CamSpec, Leeds, UK), in accordance with the ISO 13395 [73] and ISO 6878 [74] protocols, respectively. The contents of chlorides were determined via titration—Mohr’s method in accordance with the ISO 9297 protocol [75]. The concentrations of the analysed cations were determined using the ICP-OES emission spectrometer, with inductively coupled plasma (model Plasma 40 by Perkin-Elmer, Wellesley, MA, USA), in accordance with the ISO 11885 protocol [76] or using the ICP-MS mass spectrometer (model iCAP RQ (C2) by Thermo Scientific, Waltham, MA, USA), in accordance with the ISO 17294-2 protocol [77].

2.3. Suspended Particulate Matter (SPM) Samples Analysis

Water samples were collected into 2000 mL glass containers and filtered under vacuum through a 0.45-μm porosity membrane filter. The suspended matter was dried at 105 °C and then digested in aqua regia with the use of a digestion system (model DigiPREP HT by SCP SCIENCE, Baie D’Urfé, QC, Canada), in accordance with the ISO 11466 protocol [78]. The concentration of cations was defined using an ICP-OES spectrometer (model Optima 7300 DV by Perkin Elmer, Wellesley, MA, USA), in accordance with the ISO 11885 protocol [76].

2.4. Sediment Samples Analysis

Bottom sediment samples were homogenised, mixed and part of the sample was sieved through <63 µm and some through <20 µm. About 1 g of both separated grain fractions were dried at 105 °C and digested in aqua regia with the use of a digestion system (model DigiPREP HT by SCP SCIENCE, Baie D’Urfé, QC, Canada). The concentration of cations in fraction <20 µm was established using the ICP-OES spectrometer (model Optima 7300 DV by Perkin Elmer, Wellesley, MA, USA), in accordance with the ISO 11885 protocol [76] and in fraction <63 µm using flame atomic absorption spectroscopy F-AAS (model iCE 3500 by Thermo Scientific, Waltham, MA, USA) in accordance with the ISO 11047 protocol [79].

2.5. Quality Assurance and Quality Control

To ensure adequate analytical quality, all reagents were of the highest analytical purity and a blank sample was performed for each analysis. For the purpose of the definition of the method’s precision, six samples of sediment (fraction <20 µm) were prepared as prescribed above. The analysis of the method’s precision relies on the coefficient of variation (CV), i.e., standard deviation (SD) between 6 replicate samples, as an indicator of concordance described by the following formula: RSD (relative standard deviation) = (SD/mean)·100. The calculated values of RSD, in the case of all analysed elements, were ≤5%, except for arsenic.
A sample of the reference material Loam Soil ERM-CC141 was analysed, to ensure that the analytical method is accurate and provides good quality of the obtained measurement results. Precisely about 1 g of ERM material was dried at 105 °C and then digested in aqua regia under the same conditions and analysed in the same way, as in the case of samples of the Wilga River bottom sediments. The obtained results are consistent with the results of the certificate, except for arsenic. The unsatisfactory results obtained for arsenic are most likely due to a not entirely adequate method being chosen for its extraction, as it has been demonstrated that microwave aqua regia digestion gives better results for this element [80]. The system precision of ICP-MS, ICP-OES and AAS apparatus was verified by six injections of a selected solution. The performed tests demonstrated that the systems are precise enough to generate reliable results. The limits of quantification (LOQ) values for the investigated elements, discussed further are as follows (in mg/L): ICP-OES (0.005 for Cu, Li and Mn; 0.01 for Al, Ba, Cd, Co, Cr, Fe, Pb and Zn; 0.05 for Ni; 0.1 for Mg and Na; 0.2 for K and Sr; 10 for Ca); ICP-MS (0.0001 for Pb; 0.0002 for Co; 0.0003 for Cd and Sr; 0.0005 for Ba; 0.001 for Cu, Li, Mg, Ni and Zn; 0.003 for Mn; 0.005 for Al and Cr; 0.01 for Na; 0.02 for Fe; 0.05 for Ca and K); AAS (0.0029 for Mg; 0.0039 for Na; 0.0076 for Li; 0.0083 for K; 0.0092 for Ca; 0.01 for Zn; 0.013 for Cd; 0.02 for Mn; 0.033 for Cu; 0.05 for Cr and Ni; 0.052 for Fe; 0.058 for Co; 0.073 for Pb; 0.13 for Ba; 0.29 for Al).
The duplicate method was used to estimate the combined uncertainty, including sampling. According to the Eurachem Guide [81], this is the simplest and probably most cost-effective of the four methods described in it: duplicates, protocols, CTS (collaborative trial in sampling) and SPT (sampling proficiency test). The total variability of the determined parameters is the sum of the geochemical variance (spatial and/or temporal variability), sampling variance (errors generated during sampling, transport and storage of samples) and analytical variance (analytical errors) [82]. The population variances have been replaced by their estimates (s2): s2total = s2between-target + s2sampling + s2analytical [81]. The empirical method with the use of the ROBAN computer program was used to estimate the uncertainty of the results of the determination of selected elements in the Wilga sediment (fraction <20 µm). The analyses revealed that the geochemical variance related to the variability of the river parameters is predominant. However, a high contribution of sampling variance related to the sampling location was found.

3. Results and Discussion

The concentration of a wide spectrum of elements has been defined in the water, suspended particulate matter (SPM) as well as in sediments, and additionally, for the water samples, physico-chemical parameters (pH and conductivity) and anions (chlorides, nitrates, phosphates and sulphates) have been established. Some of the analysed elements will not be considered for further data analysis and discussion, due to unsatisfactory method’s precision result (arsenic), or a considerable amount of results below the limit of quantification (<LOQ) or low and irrelevant in the context of the analysis of the geochemical condition of the Wilga. The remaining results have been compiled in Table 1 (water) and in Table 2 (SPM and sediment), along with reference values such as data of the Geochemical Atlas of Europe [83] (water and sediment), the results of the Voivodeship Inspectorate of Environmental Protection in Poland [84] (water), permissible levels provided by the Regulation of the Minister of Maritime Economy and Inland Water Navigation [85] (water), the results of the Chief Inspectorate of Environmental Protection in Poland [86] (sediment), and with geochemical background values for aquatic sediments in Poland [87] (sediment).

3.1. The Impact of Waste Piles of Former “Solvay” Kraków Soda Works on the Wilga River Water and Associated Groundwater

As a result of the analysis of the waters of the Wilga River, high values of electrical conductivity (between 830 and 3600, 2264 μS/cm on average in 2019 and between 970 and 2910, 2024 μS/cm on average in 2021), as well as high concentrations of chlorides (between 61.8 and 896.4, 557.8 mg/L on average in 2019 and between 49.9 and 422.5, 261.2 mg/L on average in 2021) were obtained (Table 1). The highest values of both parameters were observed at point No. 7, located below the industrial soda waste piles (Figure 1). This is consistent with data obtained during previous research [62], according to which water flowing out of the waste ponds is strongly mineralised (contains large amounts of chlorides, sulphates, calcium ions and magnesium ions) and generates leachates from the bottom of the slopes and the banks of the Wilga River. This has been also confirmed by other research [60], where high concentrations of chloride ions (between 312 and 854 mg/L) and electrical conductivity (between 795 and 3175 μS/cm) were recorded and represented above-average values. The highest values of the concentration of chloride ions, pH and conductivity during that research [60] were observed at the measurement point located below the area of soda waste piles. Additionally, the concentrations of chlorides were the most varied in the individual points along the route of the river bed (with a general growing trend in the direction of the river mouth) and seasonally variable (during dry seasons, their concentrations were much lower than during periods of intensive rainfall). These observations suggest that chloride ions are leached from the pile area by the infiltrating rainwater. Tests carried out at a similar time as presented in this paper [67] also revealed that the highest concentrations of Cl−, Na+, Ca2+ ions and EC were present in the Wilga River below the waste ponds. Seasonal variability was also observed, i.e., the highest concentrations of the above ions were detected in autumn, which was attributed to the intensification of precipitation and the leaching of sediments into the water of the Wilga River. The large load of sodium, calcium and chloride that is discharged into the river system, is connected with the absence of effective insulation [67]. In the case of a similar post-industrial area (Soda Production Plant in Inowrocław, Poland), which featured a drainage system installed around the spoil piles, a significant reduction of the concentration of chloride ions in the analysed waters was observed [88].
The presence of chlorides may also result from the winter maintenance of roads, which in Poland is mainly based on the use of sodium chloride in various forms and mixtures. It has been demonstrated, however [89], that the risk to the water/soil environment in Kraków related to the winter maintenance of roads is not significant.
The main ecological problem related to the presence of waste piles of former “Solvay” Kraków Soda Works in the drainage basin of the Wilga River is the leaching of salts into the surface water and presumably also groundwater in the area of Kraków. Such waters are present in this area in several aquifers, in Devonian, Jurassic, Cretaceous, Tertiary and Quaternary formations, of which the most important for the economy are Quaternary waters, then Tertiary and Jurassic waters. The chemical composition of groundwater is highly variable and related to the geological structure of respective aquifers. The chemical composition of the uppermost Quaternary waters is not natural, due to contamination infiltrating these waters from the air (via precipitation), from surface waters (via infiltration from the Vistula River and its distributaries) and the soil. However, the direct influence of the waste piles is not evident in the chemical composition of groundwaters and other factors also play a significant role here. These waters are somewhat variable in different areas of Kraków, but generally demonstrate a neutral pH and a relatively high level of hardness and mineralization. The most prevalent anions are sulphates and carbonates, whereas the most prevalent cations are calcium, magnesium and iron, and sometimes also manganese. Only the high concentration of iron is of partially natural origin and is related to the saturation of Pleistocene aquifers with iron [22,23].
When comparing the results obtained during the presented research and the monitoring results of the Voivodeship Inspectorate of Environmental Protection [84], with standard values provided by the Ministry of Maritime Economy and Inland Water Navigation [85], the waters of the Wilga River should be considered as unclassified waters (ones that exceed the maximum limits for the II water quality class) in terms of parameters such as conductivity, chlorides, calcium and magnesium, and to a lesser extent also in terms of pH and phosphates (Table 1). A slightly higher pH value is related to leachates coming from the soda waste piles, which have a pH of 11–12 [62], although it seems that over the years this impact is subsiding because the previous tests have recorded higher pH values of the Wilga waters and these values also demonstrated higher variability [57]. The average concentrations of metals in the water of the Wilga River are approximately equal to or lower than the average concentrations of metals in European rivers provided by the Geochemical Atlas of Europe [83] (Table 1). However, significantly higher concentrations of chlorides, calcium and sodium were observed in the water of the Wilga River, which yet again would suggest the leaching of these elements from soda waste piles.

3.2. The Impact of Traffic and Construction Works of “Łagiewnicka Route” on the Wilga River Environment

Wilga flows through an area with a highly developed road network with heavy traffic. Therefore its waters may become infiltrated, via surface runoff, by pollutants such as petroleum-based compounds or abrasive products generated during the use of road vehicles, e.g., metals, dust, soot [91,92,93]. However, the average content of metals dissolved in water is generally low and similar in samples taken in 2019 as well as in 2021 (Table 1). No significant differences were also observed in the case of particular element concentrations obtained for sediment samples taken before (2019) and after (2021) the relocation of the Wilga bed, and the results of some of the parameters obtained for point No. 6 located in the area of the new river bed are even slightly lower than those obtained at the remaining sampling points (Table 2, Figure 4). These data show a minor impact of road transport on the geochemical condition of the river, and an insignificant impact of works connected with the construction of the “Łagiewnicka Route”.

3.3. The Long-Term Impact of Chemical Industry on the Wilga River Sediments

Wilga basin was heavily affected by the chemical industry (Kraków Fur Processing Plant, Kraków Metal Hardware Plant “Metaloplast”, Kraków Tannery—Figure 1) for several decades, which was a source of toxic elements, among others. Recent Wilga bottom sediments are enriched with elements whose concentrations exceed several times the geochemical background (GB) values established for aquatic sediments in Poland [87] (Table 2, Figure 4 and Figure 5). Deposits are most heavily contaminated with Cu (9 times higher than GB), Cr (6 times), Ni (5 times) and Ba, Co, Pb and Zn (3 times). However, it should be borne in mind that the data compared were established for different sediment fractions, so they are not completely comparable. In turn, a comparison of concentrations of the analysed elements in the sediments of the Wilga River with average values observed in the sediments of other European rivers [83] (Table 2) reveals that they are similar.
No significant differences were observed between the different sampling points or between different sampling periods—the average content of most elements in sediments extracted in 2019 and 2021 is very similar (Table 2, Figure 4 and Figure 5). However, the concentration of As and Cd was approximately halved, while the concentration of Sr increased four times. Strontium present in the sediment alongside elements such as beryllium and barium is an alkaline earth metal and is widely used in industry [94]. An analysis of a sample of soda waste carried out for the purposes of this article revealed high concentrations of elements such as barium (426 mg/kg) and strontium (205 mg/kg). Strontium salts are also present in the sulphurous mineral springs in Swoszowice [95], a settlement situated above sampling point No. 1.
Especially notable is the fact that over several decades of research documented in scientific literature, we can observe a significant improvement in the geochemical purity of the bottom sediments of the Wilga, and the average concentrations of 6 most frequently examined metals, originating from the industrial plants situated within the catchment area of the Wilga River (Cd, Cr, Cu, Ni, Pb and Zn), have decreased between several times and a dozen times, which is most clearly visible in the case of cadmium and chromium (Figure 4 and Figure 5). The results of sampling in the period 1982–1991 [56] have revealed significant differences in terms of the concentration of elements in the different samples (between several times and several dozen times) and significantly higher concentrations were observed in the area of potential pollution sources such as: leather plant, galvanic plant, tannery and bridges with busy roads. These concentrations also generally increased towards the entrance of the river into the Vistula. Sampling in 1994 [56] also revealed major differences in the concentrations of metals, but their values were generally significantly lower, which was attributed to the economic recession and the introduction of legal regulations which significantly curtailed or regulated the operations of plants especially harmful to the environment. Higher concentrations of metals continued to be observed in the areas of potential sources of pollution, such as pipes draining ponds, grass-covered waste heaps or bridges with heavy traffic. Results obtained from sampling in the period 2001–2002 [57] indicate further reduction of the concentration of metals in the superficial layer of the sediments (Figure 4 and Figure 5), whereas the impact of previously observed sources of metal contamination was already unnoticeable. The same research [57] also reported vertical variability of the concentrations of metals, wherein it was established that it was of major significance, and the most polluted was the profile layer below the depth of 10–20 cm, and that these concentrations were even several dozen times higher than those measured for the surface profile layer, which was especially visible in the case of chromium (originating from the already closed leather processing plant). In some points a reverse effect has been observed (highest concentrations in the top profile layers), which was attributed to the impact of the intensification of vehicle traffic (in the case of Pb) or to the mixing of the Wilga and Vistula sediments during the periods of backwater, in the vicinity of the entrance of Wilga into Vistula.
As mentioned above, improvement of the geochemical condition of the Wilga sediments is mostly associated with the economic recession and the introduction of legal regulations which curtailed or regulated the operations of chemical industry plants. The problem of discharging sewage to the municipal sewage network was regulated in the Act of 27 April 2001—Environmental Protection Law [96], in the Act of 7 June 2001 on the Communal Provision of Water and Communal Discharge of Sewage [97] and in the Regulation of the Minister of Construction of 14 July 2006 on the Methodology of Compliance with the Obligations of Industrial Waste Producers and the Conditions for the Discharge of Waste into Sewage Networks [98]. The existing regulations cover, among others, the conditions for the discharge of waste into sewage networks, including the acceptable values of indexes of pollution in industrial waste discharged into sewage networks, as well as the methodology of controlling the quantity and quality of waste. The present Polish regulations comply with EU law.
Metals introduced into the Wilga environment are not likely to be transported across long distances due to the rather high pH of the river’s environment and the related low mobility of metals. Therefore these elements are quickly subject to bonding in the sediments, which is also assisted by their relatively high content of fine fraction, which has the strongest sorption properties in relation to metals [99,100,101,102]. This is also confirmed by the results obtained in the course of the current research for fraction <63 μm and <20 μm (Figure 4), where the concentration of all metals (Cd, Cu, Pb and Zn) was higher in the finer fraction. An analysis of the mineral composition of the bottom sediments of the Wilga River [68] revealed that they contain clay minerals (smectite, illite, kaolinite), potassium feldspar, iron oxides, carbonate minerals (siderite) and sulphides. It was revealed that sediments are mainly comprised of the light fraction, which is polluted with cadmium and, to a lesser extent, with lead and zinc, while heavy fraction is polluted with Cu, Zn, Cd and Pb.
It seems that the current contamination of the environment of the Wilga River with elements is low. This is demonstrated not only by the gradually improving geochemical condition of the sediments but also by the low concentrations of elements in the water (Table 1) and in the suspended particulate matter (Table 2). SPM represents a good indicator of processes present in the catchment area of a given river and the anthropogenic pollution of the water environment, including by metals [103], and in polluted aquatic environments, it is indeed suspended matter that is the most polluted. This effect was still observed during previous research [57], where the concentrations of metals in suspended matter were much higher than in the sediments, and amounted to up to (in mg/kg): 60 for Cd, 506 for Cr, 517 for Cu, 250 for Ni, 320 for Pb and 1325 for Zn.
Wilga is considered to be one of the most polluted rivers in Poland, and the critical parameter of this assessment in the past was the concentration of metals, especially chromium [56,57]. The comparison of the concentrations of the analysed elements with those recorded in the Vistula, below Kraków, according to data provided by the Chief Inspectorate of Environmental Protection [86] (Table 2) demonstrates that the sediments of the Wilga are much more contaminated than the sediments of the Vistula. Due to the low discharge of the Wilga river, the load of pollutants introduced into the Vistula River is also relatively low. The average annual discharge of the Wilga River, measured near sampling point No. 9 is 1.07 m3/s [68] and of the Vistula River, measured in the vicinity of the entrance of Wilga into the Vistula—125 m3/s [104]. Over the years the general condition of the Wilga has improved significantly, which is reflected in the presented research and in the results of other authors. Currently, the bigger threat to the condition of the Wilga River is the elevated value of parameters such as phytobenthos, BOD5 (5-day Biochemical Oxygen Demand), general hardness, chlorides, sulphates, ammoniacal nitrogen, nitrite-nitrogen and benzo(a)pyrene (data provided by Voivodeship Inspectorate of Environmental Protection [84]) and its sanitary condition [105].

4. Conclusions

The conducted research allowed us to draw the following conclusions:
  • A significant and gradual improvement of the geochemical condition of the Wilga River has been observed over the last several decades, which is attributed mainly to the termination or the significant reduction of industrial activity within the river’s catchment area.
  • The impact of soda waste on the environment of the Wilga River is significant, but a reduction of the leaching of ions from the waste ponds into the river and a gradual improvement of its general condition has been observed, which is also confirmed by the observations of other authors.
  • No noticeable impact of road transport on the river’s environment has been observed, even though it flows in the vicinity of major and heavily used roads. No negative impact of the construction of the “Łagiewnicka Route” on its condition has been observed either.
  • The environment of the Wilga is still quite heavily contaminated and it has to be classified as a polluted river, but the level of this pollution has decreased and its character has changed significantly. In the past, the critical parameter was the concentration of metals, especially chromium, currently it is higher mineralization, biogenic substances and sanitary condition.

Author Contributions

Conceptualization, M.S.; methodology, M.S.; software, A.K.; validation, M.S.; formal analysis, M.S. and A.K.; investigation, M.S. and A.K.; resources, M.S. and A.K.; data curation, M.S. and A.K.; writing—original draft preparation, M.S. and A.K.; writing—review and editing, M.S. and A.K.; visualization, A.K.; supervision, M.S. and A.K.; project administration, M.S. and A.K.; funding acquisition, M.S. and A.K. Both authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the AGH University of Science and Technology, Statutory Research grant number 16.16.140.315. The APC was funded by the AGH University of Science and Technology.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Mokarram, M.; Saber, A.; Sheykhi, V. Effects of heavy metal contamination on river water quality due to release of industrial effluents. J. Clean. Prod. 2020, 227, 123380. [Google Scholar] [CrossRef]
  2. Szczepaniak-Wnuk, I.; Górska-Kostrubiec, B.; Dytłow, S.; Szwarczewski, P.; Kwapuliński, P.; Karasiński, J. Assessment of heavy metal pollution in Vistula river (Poland) sediments by using magnetic methods. Environ. Sci. Pollut. Res. 2020, 27, 24129–24144. [Google Scholar] [CrossRef]
  3. Biswas, A.K.; Tortajda, C. Water quality management: A globally neglected issue. Int. J. Water Resour. Dev. 2019, 35, 913–916. [Google Scholar] [CrossRef]
  4. Tsakiris, G. The status of the European waters in 2015: A review. Environ. Process. 2015, 2, 543–557. [Google Scholar] [CrossRef] [Green Version]
  5. Grizzetti, B.; Pistocchi, A.; Liquete, C.; Udias, A.; Bouraoui, F.; van de Bund, W. Human pressures and ecological status of European rivers. Sci. Rep. 2017, 7, 205. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  6. Posthuma, L.; Zijp, M.C.; De Zwart, D.; Van de Meent, D.; Globevnik, L.; Koprivsek, M.; Focks, A.; Van Gils, J.; Birk, S. Chemical pollution imposes limitations to the ecological status of European surface waters. Sci. Rep. 2020, 10, 14825. [Google Scholar] [CrossRef]
  7. Calatrava, J.; Martínez-Granados, D. Water buybacks to recover depleted aquifers in south-east Spain. Int. J. Water Resour. Dev. 2019, 35, 977–998. [Google Scholar] [CrossRef] [Green Version]
  8. Vieira, J.; Fonseca, A.; Vilar, V.J.P.; Boaventura, R.A.R.; Botelho, C.M.S. Water quality in Lis river, Portugal. Environ. Monit. Assess. 2012, 184, 7125–7140. [Google Scholar] [CrossRef]
  9. Hartfiel, L.; Soupir, M.; Kanwar, R.S. Malta’s Water Scarcity Challenges: Past, Present, and Future Mitigation Strategies for Sustainable Water Supplies. Sustainability 2020, 12, 9835. [Google Scholar] [CrossRef]
  10. Kanowik, W.; Kowalik, T. Usability of water in Wilga River with respect to its possible storage in small retention reservoir. Acta Sci. Pol. Form. Circumiectus 2008, 7, 23–31. (In Polish) [Google Scholar]
  11. Kubiak-Wójcicka, K.; Machula, S. Influence of Climate Changes on the State of Water Resources in Poland and Their Usage. Geosciences 2020, 10, 312. [Google Scholar] [CrossRef]
  12. Strzebońska, M.; Gruszecka-Kosowska, A.; Kostka, A. Chemistry and Microbiology of Urban Roof Runoff in Kraków, Poland with Ecological and Health Risk Implications. Appl. Sci. 2020, 10, 8554. [Google Scholar] [CrossRef]
  13. Szalińska, E. Water Quality and Management Changes Over the History of Poland. Bull. Environ. Contam. Toxicol. 2018, 100, 26–31. [Google Scholar] [CrossRef] [PubMed]
  14. Piniewski, M.; Szcześniak, M.; Kundzewicz, Z.W.; Mezghani, A.; Hov, Ø. Changes in low and high flows in the Vistula and the Odra basins: Model projections in the European-scale context. Hydrol. Process. 2017, 31, 2210–2225. [Google Scholar] [CrossRef]
  15. Helios-Rybicka, E.; Strzebońska, M. Distribution and Chemical Forms of Heavy Metals in the Flood 1997 Sediments of the Upper and Middle Odra River and its Tributaries, Poland. Acta Hydrochim. Hydrobiol. 1999, 27, 331–337. [Google Scholar] [CrossRef]
  16. Kundzewicz, Z.W.; Szamałek, K.; Kowalczak, P. The Great Flood of 1997 in Poland. Hydrolog. Sci. J. 1999, 44, 855–870. [Google Scholar] [CrossRef]
  17. Adamiec, E.; Helios-Rybicka, E. Changes of heavy metals concentrations in suspended matter of the Odra River after the flood in November 1997. In Proceedings of the Symposium Programme of Fifth International Symposium and Exhibition on Environmental Contamination in Central and Eastern Europe, Prague, Czech Republic, 12–14 September 2000; p. 220. [Google Scholar]
  18. Dobrowolski, A.; Czarnecka, H.; Ostrowski, J.; Zaniewska, M. Floods in Poland from 1946 to 2001—Origin, territorial extent and frequency. In Proceedings of the Conference “Risks Caused by the Geodynamic Phenomena in Europe”, Wysowa, Poland, 20–22 May 2004; pp. 69–76. [Google Scholar]
  19. Bissolli, P.; Friedrich, K.; Rapp, J.; Ziese, M. Flooding in eastern central Europe in May 2010—Reasons, evolution and climatological assessment. Weather 2011, 66, 147–153. [Google Scholar] [CrossRef]
  20. Strzebońska, M.; Kostka, A.; Helios-Rybicka, E.; Jarosz-Krzemińska, E. Effect of Flooding on Heavy Metals Contamination of Vistula Floodplain Sediments in Cracow; Historical Mining and Smelting as the Most Important Source of Pollution. Pol. J. Environ. Stud. 2015, 24, 1317–1326. [Google Scholar] [CrossRef]
  21. Kowalczak, P.; Kundzewicz, Z.W. Water-related conflicts in urban areas in Poland. Hydrolog. Sci. J. 2011, 54, 588–596. [Google Scholar] [CrossRef] [Green Version]
  22. Pociask-Karteczka, J. Anthropogenic Changes in the Water Conditions in Cracow (East-Central Europe) Since the Second World War. J. Environ. Hydrol. 1994, 2, 14–23. [Google Scholar]
  23. Pociask-Karteczka, J. Changes in the water conditions in the area of Kraków. Zesz. Nauk. Uniw. Jagiellońskiego MCXLIV Pr. Geogr. 1994, 96, 1–38. (In Polish) [Google Scholar]
  24. Kostka, A.; Leśniak, A. Natural and Anthropogenic Origin of Metals in Lacustrine Sediments; Assessment and Consequences—A Case Study of Wigry Lake (Poland). Minerals 2021, 11, 158. [Google Scholar] [CrossRef]
  25. Förstner, U. Sediment-associated contaminants—An overview of scientific bases for developing remedial options. Hydrobiologia 1987, 149, 221–246. [Google Scholar] [CrossRef]
  26. Dinis, P.; Garzanti, E.; Vermeesch, P.; Huvi, J. Climatic zonation and weathering control on sediment composition (Angola). Chem. Geol. 2017, 467, 110–121. [Google Scholar] [CrossRef] [Green Version]
  27. Hamid, A.; Bhat, S.U.; Jehangir, A. Local determinants influencing stream water quality. Appl. Water Sci. 2020, 10, 24. [Google Scholar] [CrossRef] [Green Version]
  28. Owens, P.N. Conceptual Models and Budgets for Sediment Management at the River Basin Scale. J. Soils Sediments 2005, 5, 201–212. [Google Scholar] [CrossRef]
  29. Burton, G.A., Jr. Sediment quality criteria in use around the world. Limnology 2002, 3, 65–75. [Google Scholar] [CrossRef]
  30. Matschullat, J.; Ottenstein, R.; Reimann, C. Geochemical background—Can we calculate it? Environ. Geol. 2000, 39, 990–1000. [Google Scholar] [CrossRef]
  31. Aleksander-Kwaterczak, U.; Kostka, A.; Leśniak, A. Multiparameter assessment of select metal distribution in lacustrine sediments. J. Soils Sediments 2021, 21, 512–529. [Google Scholar] [CrossRef]
  32. Ali, H.; Khan, E.; Ilahi, I. Environmental Chemistry and Ecotoxicology of Hazardous Heavy Metals: Environmental Persistence, Toxicity, and Bioaccumulation. J. Chem. 2019, 6730305. [Google Scholar] [CrossRef] [Green Version]
  33. Kostka, A.; Leśniak, A. Spatial and geochemical aspects of heavy metal distribution in lacustrine sediments, using the example of Lake Wigry (Poland). Chemosphere 2020, 240, 124879. [Google Scholar] [CrossRef] [PubMed]
  34. Meybeck, M. Heavy metal contamination in rivers across the globe: An indicator of complex interactions between societies and catchments. In Proceedings of the H04, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, 22–26 July 2013; pp. 3–16. [Google Scholar]
  35. Macklin, M.G.; Klimek, K. Dispersal, storage and transformation of metal contaminated alluvium in the upper Vistula basin, southwest Poland. Appl. Geogr. 1992, 12, 7–30. [Google Scholar] [CrossRef]
  36. Helios-Rybicka, E. Impact of mining and metallurgical industries on the environment in Poland. Appl. Geochem. 1996, 11, 3–9. [Google Scholar] [CrossRef]
  37. Bojakowska, I.; Sokołowska, G.; Gliwicz, T. Heavy metals in recent alluvium of the Odra River. Geol. Q. 1997, 41, 395–404. [Google Scholar]
  38. Adamiec, E.; Helios-Rybicka, E. Distribution of Pollutants in the Odra River System Part IV. Heavy Metal Distribution in Water of the Upper and Middle Odra River, 1998–2000. Pol. J. Environ. Stud. 2002, 11, 669–673. [Google Scholar]
  39. Helios-Rybicka, E.; Adamiec, E.; Aleksander-Kwaterczak, U. Distribution of trace metals in the Odra River system: Water—Suspended matter—Sediments. Limnologica 2005, 35, 185–198. [Google Scholar] [CrossRef] [Green Version]
  40. Gielar, A.; Helios-Rybicka, E.; Möller, S.; Einax, J.W. Multivariate analysis of sediment data from the upper and middle Odra River (Poland). Appl. Geochem. 2012, 27, 1540–1545. [Google Scholar] [CrossRef]
  41. Ciszewski. D. Flood-related changes in heavy metal concentrations within sediments of the Biała Przemsza River. Geomorphology 2001, 40, 205–218. [Google Scholar] [CrossRef]
  42. Ciszewski, D. Pollution of Mala Panew River sediments by heavy metal: Part I. Effect of changes in river bed morphology. Pol. J. Environ. Stud. 2004, 13, 589–595. [Google Scholar]
  43. Budek, L.; Wardas, M.; Kijas, A.; Rembalska, R. Contamination with heavy metals of the Serafa River environment (Cracow area)—Comparison of the situation before and after the flood of 1997. Geologia 2004, 30, 175–189. (In Polish) [Google Scholar]
  44. Aleksander-Kwaterczak, U.; Wardas, M.; Fuk, A.; Dudek, K. A threat to the Mała Panew River ecosystem due to Cd and Zn above standard concentrations in its bottom sediments. Pol. J. Environ. Stud. 2006, 15, 631–634. [Google Scholar]
  45. Pawlikowski, M.; Szalińska, E.; Wardas, M.; Dominik, J. Chromium Originating from Tanneries in River Sediments: A Preliminary Investigation from the Upper Dunajec River (Poland). Pol. J. Environ. Stud. 2006, 15, 885–894. [Google Scholar]
  46. Aleksander-Kwaterczak, U.; Helios-Rybicka, E. Contaminated sediments as a potential source of Zn, Pb, and Cd for a river system in the historical metalliferous ore mining and smelting industry area of South Poland. J. Soils Sediments 2009, 9, 13–22. [Google Scholar] [CrossRef]
  47. Ciszewski, D.; Kubsik, U.; Aleksander-Kwaterczak, U. Long-term dispersal of heavy metals in a catchment affected by historic lead and zinc mining. J. Soils Sediments 2012, 12, 1445–1462. [Google Scholar] [CrossRef] [Green Version]
  48. Ciszewski, D.; Aleksander-Kwaterczak, U.; Pociecha, A.; Szarek-Gwiazda, E.; Waloszek, A.; Wilk-Woźniak, E. Small effects of a large sediment contamination with heavy metals on aquatic organisms in the vicinity of an abandoned lead and zinc mine. Environ. Monit. Assess. 2013, 185, 9825–9842. [Google Scholar] [CrossRef] [Green Version]
  49. Ciszewski, D.; Bijata, P. Reconstruction of post-mining attenuation of heavy metal pollution in sediment of the Zlatý Potok, Eastern Sudety Mts. Carpath. J. Earth Environ. Sci. 2014, 9, 109–120. [Google Scholar]
  50. Szarek-Gwiazda, E.; Michailova, P.; Ilkova, J.; Kownacki, A.; Ciszewski, D.; Aleksander-Kwaterczak, U. The effect of long-term contamination by heavy metals on community and genome alterations of Chironomidae (Diptera) in a stream with mine drainage water (southern Poland). Oceanol. Hydrobiol. Stud. 2014, 42, 460–469. [Google Scholar] [CrossRef]
  51. Aleksander-Kwaterczak, U.; Ciszewski, D. Pollutant dispersal in groundwater and sediments of gaining and losing river reaches affected by metal mining. Environ. Earth Sci. 2016, 75, 95. [Google Scholar] [CrossRef] [Green Version]
  52. Jabłońska-Czapla, M.; Nocoń, K.; Szopa, S.; Łyko, A. Impact of the Pb and Zn ore mining industry on the pollution of the Biała Przemsza River, Poland. Environ. Monit. Assess. 2016, 188, 262. [Google Scholar] [CrossRef] [Green Version]
  53. Strzebońska, M.; Jarosz-Krzemińska, E.; Adamiec, E. Assessing Historical Mining and Smelting Effects on Heavy Metal Pollution of River Systems over Span of Two Decades. Water Air Soil Pollut. 2017, 228, 141. [Google Scholar] [CrossRef] [Green Version]
  54. Aleksander-Kwaterczak, U.; Plenzler, D. Contamination of small urban watercourses on the example of a stream in Krakow (Poland). Environ. Earth Sci. 2019, 78, 530. [Google Scholar] [CrossRef] [Green Version]
  55. Ciszewski, D. The past and prognosis of mining cessation impact on river sediment pollution. J. Soils Sediments 2019, 19, 393–402. [Google Scholar] [CrossRef] [Green Version]
  56. Wardas, M.; Budek, L.; Helios-Rybicka, E. Variability of heavy metals content in bottom sediments of the Wilga River, a tributary of the Vistula River (Kraków area, Poland). Appl. Geochem. 1996, 11, 197–202. [Google Scholar] [CrossRef]
  57. Wardas, M.; Łojan, E.; Kuboń, E. Changes in land development in the valley of the Wilga River within Cracow area and their influence on the water environment. Geologia 2004, 30, 215–231. (In Polish) [Google Scholar]
  58. Wardas-Lasoń, M. The Influence of Sewage System on the Functioning and Quality of Krakow’s Watercourses. J. Geol. Res. 2014, 2014, 910982. [Google Scholar] [CrossRef] [Green Version]
  59. Trasa Łagiewnicka, S.A. Available online: https://3obwodnica.krakow.pl (accessed on 8 June 2021).
  60. Gliniak, M.; Pawul, M.; Sobczyk, W. Impact of the transport and postindustrial landfills of Cracow Soda Works “Solvay” on the status and quality of water in Wilga River in Krakow. Logistyka 2014, 4, 4295–4302. (In Polish) [Google Scholar]
  61. Sutkowska, K.; Teper, L. Impact of Solvay Waste Alkalinity on the Leaching of Heavy Metals in A 100 Year-Old Landfill. In Proceedings of the World Congress on New Technologies (NewTech 2015), Barcelona, Spain, 15–17 July 2015; p. 169. [Google Scholar]
  62. Sroczyński, W.; Skrzypczak, R.; Syposz-Łuczak, B.; Wota, A. “Krakow Białe Morza”—Chosen problems of management and revitalization. Zesz. Nauk. Inst. Gospod. Surowcami Miner. Energią PAN 2009, 76, 31–43. (In Polish) [Google Scholar]
  63. Hong, J.; Chen, W.; Wang, Y.; Xu, C.; Xu, X. Life cycle assessment of caustic soda production: A case study in China. J. Clean. Prod. 2014, 66, 113–120. [Google Scholar] [CrossRef]
  64. Glasby, G.P.; Szefer, P. Marine pollution in Gdansk Bay, Puck Bay and the Vistula Lagoon, Poland: An overview. Sci. Total Environ. 1998, 212, 49–57. [Google Scholar] [CrossRef]
  65. HELCOM. Hazardous substances in the Baltic Sea—An integrated thematic assessment of hazardous substances in the Baltic Sea. In Baltic Sea Environment Proceedings No. 120B; Helsinki Commission, Baltic Marine Environment Protection Commission: Helsinki, Finland, 2010; Available online: https://helcom.fi/media/publications/BSEP120B.pdf (accessed on 8 June 2021).
  66. Lehtonen, K.K.; Schiedek, D.; Köhler, A.; Lang, T.; Vuorinen, P.J.; Förlin, L.; Baršienė, J.; Pempkowiak, J.; Gercken, J. The BEEP project in the Baltic Sea: Overview of results and outline for a regional biological effects monitoring strategy. Mar. Pollut. Bull. 2006, 53, 523–537. [Google Scholar] [CrossRef] [PubMed]
  67. Likus-Cieślik, J.; Pietrzykowski, M. The Influence of Sedimentation Ponds of the Former Soda “Solvay” Plant in Krakow on the Chemistry of the Wilga River. Sustainability 2021, 13, 993. [Google Scholar] [CrossRef]
  68. Łojan, E. Influence of Mineral Components on Geochemistry of Heavy Metals in Sediments of the Wilga River. Ph.D. Thesis, AGH University of Science and Technology, Kraków, Poland, 2008. (In Polish). [Google Scholar]
  69. Gliniak, M.; Sobczyk, W. Proposal of brownfield land development on the example of the landfills of former Soda Krakow Works “Solvay”. J. Ecol. Eng. 2016, 17, 96–100. [Google Scholar] [CrossRef] [Green Version]
  70. Krakowskie Zakłady Garbarskie, S.A. Available online: https://www.kzgsa.com/historia.php (accessed on 2 August 2021).
  71. International Organization for Standardization. ISO 10523. Water Quality—Determination of pH; International Organization for Standardization: Geneva, Switzerland, 2008. [Google Scholar]
  72. International Organization for Standardization. ISO 7888. Water Quality—Determination of Electrical Conductivity; International Organization for Standardization: Geneva, Switzerland, 1985. [Google Scholar]
  73. International Organization for Standardization. ISO 13395. Water Quality—Determination of Nitrite Nitrogen and Nitrate Nitrogen and the Sum of Both by Flow Analysis (CFA and FIA) and Spectrometric Detection; International Organization for Standardization: Geneva, Switzerland, 1996. [Google Scholar]
  74. International Organization for Standardization. ISO 6878. Water Quality—Determination of Phosphorus—Ammonium Molybdate Spectrometric Method; International Organization for Standardization: Geneva, Switzerland, 2004. [Google Scholar]
  75. International Organization for Standardization. ISO 9297. Water Quality—Determination of Chloride—Silver Nitrate Titration with Chromate Indicator (Mohr’s Method); International Organization for Standardization: Geneva, Switzerland, 1989. [Google Scholar]
  76. International Organization for Standardization. ISO 11885. Water Quality—Determination of Selected Elements by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES); International Organization for Standardization: Geneva, Switzerland, 2007. [Google Scholar]
  77. International Organization for Standardization. ISO 17294-2. Water Quality—Application of Inductively Coupled Plasma Mass Spectrometry (ICP-MS)—Part 2: Determination of Selected Elements Including Uranium Isotopes; International Organization for Standardization: Geneva, Switzerland, 2016. [Google Scholar]
  78. International Organization for Standardization. ISO 11466. Soil Quality—Extraction of Trace Elements Soluble in Aqua Regia; International Organization for Standardization: Geneva, Switzerland, 1995. [Google Scholar]
  79. International Organization for Standardization. ISO 11047. Soil Quality—Determination of Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Nickel and Zinc—Flame and Electrothermal Atomic Absorption Spectrometric Methods; International Organization for Standardization: Geneva, Switzerland, 1998. [Google Scholar]
  80. Tighe, M.; Lockwood, P.; Wilson, S.; Lisle, L. Comparison of Digestion Methods for ICP-OES Analysis of a Wide Range of Analytes in Heavy Metal Contaminated Soil Samples with Specific Reference to Arsenic and Antimony. Commun. Soil Sci. Plant Anal. 2004, 35, 1369–1385. [Google Scholar] [CrossRef]
  81. Ramsey, M.H.; Ellison, S.L.R.; Rostron, P. (Eds.) Eurachem/EUROLAB/CITAC/Nordtest/AMC Guide. In Measurement Uncertainty Arising from Sampling: A Guide to Methods and Approaches, 2nd ed.; Eurachem: Teddington, UK, 2019; Available online: https://www.eurachem.org/index.php/publications/guides/musamp (accessed on 10 June 2021).
  82. Kmiecik, E. Methodological Aspects of Assessing the Chemical Status of Groundwater; Wydawnictwa AGH: Kraków, Poland, 2011. (In Polish) [Google Scholar]
  83. Salminen, R. (Ed.) Geochemical Atlas of Europe; Geological Survey of Finland: Espoo, Finland, 2005; Available online: http://weppi.gtk.fi/publ/foregsatlas/index.php (accessed on 2 August 2021).
  84. Voivodeship Inspectorate of Environmental Protection in Poland. Available online: http://krakow.pios.gov.pl/stan-srodowiska/monitoring-wod/monitoring-wod-powierzchniowych (accessed on 2 June 2021).
  85. Ministry of Maritime Economy and Inland Water Navigation. Regulation of the Minister of Maritime Economy and Inland Water Navigation of 11 October 2019 on the Classification of the Ecological Condition, Ecological Potential and Chemical Condition and the Method of Classification of the Condition of Homogeneous Areas of Surface Waters, and on Environmental Quality Standards for Priority Substances; Item 2149; Journal of Laws: Warszawa, Poland, 2019. (In Polish) [Google Scholar]
  86. Chief Inspectorate of Environmental Protection in Poland. Available online: https://www.gios.gov.pl/pl/stan-srodowiska/monitoring-wod (accessed on 4 June 2021).
  87. Bojakowska, I.; Sokołowska, G. Geochemical purity classes of aquatic sediments. Prz. Geol. 1998, 46, 49–54. (In Polish) [Google Scholar]
  88. Gołub, A.; Piekutin, J. Effectiveness of Measures Taken to Protect Waters by Example of Soda Production Plant in Inowrocław. J. Ecol. Eng. 2018, 19, 144–149. [Google Scholar] [CrossRef]
  89. Kostka, A.; Strzebońska, M.; Sobczyk, M.; Zakrzewska, M.; Bochenek, A. The effect of de-icing roads with salt on the environment in Kraków, Poland. Geol. Geophys. Environ. 2019, 45, 195–205. [Google Scholar] [CrossRef]
  90. WHO. GEMS/Food-EURO Second Workshop on Reliable Evaluation of Low-Level Contamination of Food: Report on a Workshop in the Frame of GEMS Food-EURO; World Health Organization: Geneva, Switzerland, 1995. [Google Scholar]
  91. Adamiec, E.; Jarosz-Krzemińska, E.; Wieszała, R. Heavy metals from non-exhaust vehicle emissions in urban and motorway road dusts. Environ. Monit. Asses. 2016, 188, 369. [Google Scholar] [CrossRef] [Green Version]
  92. Adamiec, E. Chemical fractionation and mobility of traffic-related elements in road environments. Environ. Geochem. Health 2017, 39, 1457–1468. [Google Scholar] [CrossRef] [Green Version]
  93. Adamiec, E.; Jarosz-Krzemińska, E. Human health risk assessment associated with contaminants in the finest fraction of sidewalk dust collected in proximity to trafficked roads. Sci. Rep. 2019, 9, 16364. [Google Scholar] [CrossRef]
  94. Machowski, R.; Rzętała, M.A.; Rzętała, M.; Solarski, M. Anthropogenic enrichment of the chemical composition of bottom sediments of water bodies in the neighborhood of a non-ferrous metal smelter (Silesian Upland, Southern Poland). Sci. Rep. 2019, 9, 14445. [Google Scholar] [CrossRef]
  95. Rajchel, L. Mineral waters and acratopegs of Kraków. Prz. Geol. 1998, 46, 1139–1145. (In Polish) [Google Scholar]
  96. Parliament of Poland. Act of 27 April 2001—Environmental Protection Law; Item 627; Journal of Laws: Warszawa, Poland, 2001. (In Polish) [Google Scholar]
  97. Parliament of Poland. Act of 7 June 2001 on the Communal Provision of Water and Communal Discharge of Sewage; Item 747; Journal of Laws: Warszawa, Poland, 2001. (In Polish) [Google Scholar]
  98. Ministry of Construction. Regulation of the Minister of Construction of 14 July 2006 on the Methodology of Compliance with the Obligations of Industrial Waste Producers and the Conditions for the Discharge of Waste into Sewage Networks; Item 964; Journal of Laws: Warszawa, Poland, 2001. (In Polish) [Google Scholar]
  99. Salomons, W.; Förstner, U. Metals in the Hydrocycle; Springer: Berlin/Heidelberg, Germany, 1984. [Google Scholar]
  100. Selvaraj, K.; Mohan, V.R.; Szefer, P. Evaluation of metal contamination in coastal sediments of the Bay of Bengal, India: Geochemical and statistical approaches. Mar. Pollut. Bull. 2004, 49, 174–185. [Google Scholar] [CrossRef] [PubMed]
  101. Tylmann, W.; Łysek, K.; Kinder, M.; Pempkowiak, J. Regional Pattern of Heavy Metal Content in Lake Sediments in Northeastern Poland. Water Air Soil Pollut. 2011, 216, 217–228. [Google Scholar] [CrossRef] [Green Version]
  102. Kuriata-Potasznik, A.; Szymczyk, S.; Skwierawski, A.; Glińska-Lewczuk, K.; Cymes, I. Heavy Metal Contamination in the Surface Layer of Bottom Sediments in a Flow-Through Lake: A Case Study of Lake Symsar in Northern Poland. Water 2016, 8, 358. [Google Scholar] [CrossRef]
  103. Adamiec, E. Suspended Particulate Matter as an Indicator of Metals Pollution in Riverin System. Ecol. Chem. Eng. A 2013, 20, 31–38. [Google Scholar] [CrossRef]
  104. Jagoda, A.; Żukowski, W.; Dąbrowska, B. Caffeine in Cracow rivers. Czas. Tech. Sr. 2011, 108, 99–108. (In Polish) [Google Scholar]
  105. Greczek-Stachura, M.; Zagata-Leśnicka, P.; Ślęczka, M. Analysis of the coliform in the Wilga River (southern Poland). Ann. Univ. Paedag. Crac. Stud. Nat. 2016, 1, 190–195. [Google Scholar]
Minerals 11 00908 g001 550
Figure 1. Study area: (A)—location of the study area (Kraków city) on the map of Poland; (B)—sampling cites at the Wilga River (in general); (C)—sampling cites at the Wilga River (in details); 1—boundaries of the Kraków city and its districts; 2—first ringway of Kraków; 3—second ringway of Kraków; 4—third ringway of Kraków (existing sections are marked with a continuous line, while planned sections are marked with a dashed line); 5—“Łagiewnicka Route”, a section of the third ringway of Kraków under construction; 6—fourth ringway of Kraków (existing sections are marked with a continuous line, while planned sections are marked with a dashed line); 7—relocated section of the Wilga River (Figure 2); 8—waste piles of former “Solvay” Kraków Soda Works (Figure 3); 9—locations of chemical industry objects (KFPP—Kraków Fur Processing Plant, KMHP—Kraków Metal Hardware Plant “Metaloplast”, KT—Kraków Tannery); 10—sampling points.
Figure 1. Study area: (A)—location of the study area (Kraków city) on the map of Poland; (B)—sampling cites at the Wilga River (in general); (C)—sampling cites at the Wilga River (in details); 1—boundaries of the Kraków city and its districts; 2—first ringway of Kraków; 3—second ringway of Kraków; 4—third ringway of Kraków (existing sections are marked with a continuous line, while planned sections are marked with a dashed line); 5—“Łagiewnicka Route”, a section of the third ringway of Kraków under construction; 6—fourth ringway of Kraków (existing sections are marked with a continuous line, while planned sections are marked with a dashed line); 7—relocated section of the Wilga River (Figure 2); 8—waste piles of former “Solvay” Kraków Soda Works (Figure 3); 9—locations of chemical industry objects (KFPP—Kraków Fur Processing Plant, KMHP—Kraków Metal Hardware Plant “Metaloplast”, KT—Kraków Tannery); 10—sampling points.
Minerals 11 00908 g001
Minerals 11 00908 g002 550
Figure 2. Relocated section of the Wilga River: (A)—photomap with the indication of the old river bed (light blue) and new river bed (dark blue) (obtained courtesy of Trasa Łagiewnicka S.A. [59]), as well as the location of sampling point No. 6 (red dot); (B)—section of old river bed seen from the vicinity of sampling point No. 6; (C)—section of new river bed seen from the vicinity of sampling point No. 6 (Figure 1).
Figure 2. Relocated section of the Wilga River: (A)—photomap with the indication of the old river bed (light blue) and new river bed (dark blue) (obtained courtesy of Trasa Łagiewnicka S.A. [59]), as well as the location of sampling point No. 6 (red dot); (B)—section of old river bed seen from the vicinity of sampling point No. 6; (C)—section of new river bed seen from the vicinity of sampling point No. 6 (Figure 1).
Minerals 11 00908 g002
Minerals 11 00908 g003 550
Figure 3. Wastes of former “Solvay” Kraków Soda Works, so-called “White Seas” (pol. Białe Morza): (A)—vicinity of sampling point No. 6 (Figure 1) during construction works and relocation of the Wilga River bed (obtained courtesy of Trasa Łagiewnicka S.A. [59]), with waste piles visible in the background (red arrow); (B)—soda waste up close; (C)—non-processed soda waste piles in the vicinity of the Wilga River, next to the recultivated and redeveloped area.
Figure 3. Wastes of former “Solvay” Kraków Soda Works, so-called “White Seas” (pol. Białe Morza): (A)—vicinity of sampling point No. 6 (Figure 1) during construction works and relocation of the Wilga River bed (obtained courtesy of Trasa Łagiewnicka S.A. [59]), with waste piles visible in the background (red arrow); (B)—soda waste up close; (C)—non-processed soda waste piles in the vicinity of the Wilga River, next to the recultivated and redeveloped area.
Minerals 11 00908 g003
Minerals 11 00908 g004 550
Figure 4. Comparison of selected metal concentrations (Cd, Cu, Pb and Zn) in Wilga River bottom sediments (fraction <20 μm and <63 μm; 2019 and 2021) with geochemical background [87] and with data from previous studies: mean concentrations in fraction <63 μm from two sampling campaigns (1982–1991 and 1994), according to [56] and mean concentrations in fraction <63 μm from sampling campaign 2001–2002, according to [57].
Figure 4. Comparison of selected metal concentrations (Cd, Cu, Pb and Zn) in Wilga River bottom sediments (fraction <20 μm and <63 μm; 2019 and 2021) with geochemical background [87] and with data from previous studies: mean concentrations in fraction <63 μm from two sampling campaigns (1982–1991 and 1994), according to [56] and mean concentrations in fraction <63 μm from sampling campaign 2001–2002, according to [57].
Minerals 11 00908 g004
Minerals 11 00908 g005 550
Figure 5. Comparison of selected metal concentrations (Cr and Ni) in Wilga River bottom sediments (fraction <20 μm; 2019 and 2021) with geochemical background [87] and with data from previous studies: mean concentrations in fraction <63 μm from two sampling campaigns (1982–1991 and 1994), according to [56] and mean concentrations in fraction <63 μm from sampling campaign 2001–2002, according to [57].
Figure 5. Comparison of selected metal concentrations (Cr and Ni) in Wilga River bottom sediments (fraction <20 μm; 2019 and 2021) with geochemical background [87] and with data from previous studies: mean concentrations in fraction <63 μm from two sampling campaigns (1982–1991 and 1994), according to [56] and mean concentrations in fraction <63 μm from sampling campaign 2001–2002, according to [57].
Minerals 11 00908 g005
Table
Table 1. Statistical parameters in the Wilga River water (2017, 2019 and 2021), European rivers and permissible levels of the selected parameters.
Table 1. Statistical parameters in the Wilga River water (2017, 2019 and 2021), European rivers and permissible levels of the selected parameters.
ParameterUnitWilga 2019 (This Study)
Min–Max (Mean)		Wilga 2021 (This Study)
Min–Max (Mean)		Wilga 2017 [84]
Mean *		Water of European Rivers [83]
Min–Max (Mean)		Class I
[85] **		Class II
[85] **
pH–7.0–7.5 (7.3)7.6–8.2 (8.1)7.82.2–9.8 (7.5)7.4–8.06.5–8.0
ECµS/cm830–3600 (2264)970–2910 (2024)2834<500–1,710,000 (44,600)≤542≤677
Cl−mg/L61.8–896.4 (557.8)49.9–422.5 (261.2)922.50.14–4560 (33.3)≤29.9≤44.8
N-NO3mg/L0.20–2.43 (1.48)nd1.5<0.009–24.2 (2.05)≤2.0≤5.0
P-PO4mg/L0.031–0.525 (0.165)nd0.016nd≤0.065≤0.101
SO4mg/Lnd61.6–119.6 (96.9)120.80.3–2420 (52.1)≤49.5≤79.8
Almg/L<LOQ–0.020 (0.013)0.082–0.510 (0.198)nd0.0007–3.37 (0.0755)≤0.4≤0.4
Bamg/L0.018–0.092 (0.064)0.029–0.048 (0.040)0.0620.0002–0.436 (0.0354)≤0.5≤0.5
Camg/L66.0–318.3 (221.2)93.2–210.0 (157.9)nd0.226–592 (55.2)≤80.1≤89.5
Cdmg/L<LOQ–<LOQ (<LOQ)<LOQ–<LOQ (<LOQ)0.03<0.000002–0.00125 (0.000026)0.00045 ***0.00045 ***
Comg/L<LOQ–<LOQ (<LOQ)0.00021–0.00034 (0.00026)nd0.00001–0.0157 (0.000333)≤0.05≤0.05
Crmg/L<LOQ–<LOQ (<LOQ)<LOQ–<LOQ (<LOQ)nd<0.00001–0.043 (0.000792)≤0.05≤0.05
Cumg/L<LOQ–<LOQ (<LOQ)<LOQ–<LOQ (<LOQ)<LOQ0.00008–0.0146 (0.00123)≤0.05≤0.05
Femg/L0.016–0.074 (0.039)0.179–0.787 (0.538)nd<0.001–4.82 (0.268)––
Kmg/L1.32–7.91 (4.42)3.64–5.53 (4.78)nd<0.01–182 (3.07)––
Limg/L<LOQ–0.010 (0.009)0.005–0.010 (0.008)nd<0.000005–0.356 (0.00667)––
Mgmg/L11.25–19.17 (14.88)9.48–13.76 (12.35)nd0.048–230 (11.5)≤6.6≤12.0
Mnmg/L<LOQ–<LOQ (<LOQ)0.092–0.219 (0.170)nd<0.00005–3.01 (0.0567)––
Namg/L32.6–304.5 (191.0)31.19–167.06 (101.43)nd0.231–4030 (23.1)––
Nimg/L<LOQ–<LOQ (<LOQ)0.0014–0.0020 (0.0016)2.00.00003–0.0246 (0.00243)0.034 ***0.034 ***
Pbmg/L<LOQ–<LOQ (<LOQ)<LOQ–0.00053 (0.00027)nd<0.000005–0.0106 (0.000224)0.014 ***0.014 ***
Srmg/L0.36–1.35 (0.92)0.40–1.08 (0.71)nd0.001-13.6 (0.327)––
Znmg/L<LOQ–0.059 (0.036)<LOQ–<LOQ (<LOQ)0.0500.00009–0.31 (0.00601)≤1≤1
nd—not determined; <LOQ—below the limit of quantification (<LOQ were substituted with LOQ/2 in the calculations of mean values [85,90]); * data based on the results of the Voivodeship Inspectorate of Environmental Protection [84]; ** permissible levels of parameters for class I and II, respectively, of water quality, provided by the Ministry of Maritime Economy and Inland Water Navigation [85]; *** maximum allowable concentration according to environmental quality standards—MAC-EQS [85].
Table
Table 2. Statistical parameters of selected elements in suspended particulate matter (SPM) and sediment of the Wilga River (2019, 2021), in Vistula River sediment (2018), European rivers and geochemical background for aquatic sediments in Poland.
Table 2. Statistical parameters of selected elements in suspended particulate matter (SPM) and sediment of the Wilga River (2019, 2021), in Vistula River sediment (2018), European rivers and geochemical background for aquatic sediments in Poland.
Parameter [mg/kg]2019 (This Study) Wilga Suspended Particulate Matter
Min–Max (Mean)		2019 (This Study)
Wilga Sediment
(Fraction <20 μm)
Min–Max (Mean)		2021 (This Study)
Wilga Sediment
(Fraction <20 μm)
Min–Max (Mean)		2018 Vistula Sediment below Kraków (Fraction <2 mm) [86] *Stream Sediments of European
Rivers [83]
Min–Max (Mean)		Geochemical Background for Aquatic Sediments in Poland [87]
Al8665–15,607 (11,827)13,717–21,085 (17,622)16,064–21,201 (17,750)1500nd–
Ba126–545 (277)109–328 (168)95–193 (146)19.04.0–3120 (117)<52
Ca22,474–79,621 (50,869)15,452–38,280 (24,795)16,241–50,871 (31,076)1400nd–
Cd<LOQ–<LOQ (<LOQ)0.522–1.041 (0.701)<LOQ–1.068 (0.498)0.226<0.02–43.1 (0.527)<0.5
Co<LOQ–<LOQ (<LOQ)8.81–13.06 (10.58)8.53–11.54 (9.89)<0.20<1.0–245 (10.3)<3
Cr<LOQ–<LOQ (<LOQ)34.2–47.2 (40.5)29.9–40.9 (36.5)3.052..0–1750 (31.0)<6
Cu59.7–576.5 (275.2)36.3–98.9 (58.6)40.8–88.6 (63.5)3.941.0–998 (19.0)<7
Fe30,850–148,422 (82,648)22,935–31,875 (27,243)23,090–29,668 (25,772)7100600–200,000 (22,500)–
K<LOQ–<LOQ (<LOQ)2980–4224 (3688)2847–4763 (3317)240nd–
Li<LOQ–<LOQ (<LOQ)15.6–23.4 (18.8)21.4–60.4 (28.5)nd0.28–271 (29.7)–
Mg4602–10,298 (7716)4649–8401 (5837)3839–12,860 (6716)600nd–
Mn3583–21,884 (11,336)375–1009 (640)491–1079 (660)33024–18,900 (716)–
Na<LOQ–<LOQ (<LOQ)274–3159 (1000)315–3693 (1257)ndnd–
Ni<LOQ–<LOQ (<LOQ)26.2–40.2 (32.0)27.4–39.0 (31.3)3.762.0–1200 (28.6)<6
Pb<LOQ–<LOQ (<LOQ)31.8–71.8 (45.7)26.2–57.1 (41.6)<1.00<3.0–4880 (29.8)<15
Sr<LOQ–<LOQ (<LOQ)56.6–110.6 (77.9)44.5–1603.3 (239.7)11.031–1352 (171)–
Zn87–1017 (455)154–383 (250)130–358 (249)13.77.0–11,400 (98)<73
nd—not determined; <LOQ—below the limit of quantification (<LOQ were substituted with LOQ/2 in calculations of mean values [85,90]); * data based on the results of the Chief Inspectorate of Environmental Protection in 2018 [86].
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Strzebońska, M.; Kostka, A. Geochemical State of Wilga River Environment in Kraków (Poland)—Historical Aspects and Existing Issues. Minerals 2021, 11, 908. https://doi.org/10.3390/min11080908

AMA Style

Strzebońska M, Kostka A. Geochemical State of Wilga River Environment in Kraków (Poland)—Historical Aspects and Existing Issues. Minerals. 2021; 11(8):908. https://doi.org/10.3390/min11080908

Chicago/Turabian Style

Strzebońska, Magdalena, and Anna Kostka. 2021. "Geochemical State of Wilga River Environment in Kraków (Poland)—Historical Aspects and Existing Issues" Minerals 11, no. 8: 908. https://doi.org/10.3390/min11080908

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop