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EN
The important role of zooplankton in linking different trophic levels has been the subject of extensive research, highlighting their crucial contribution to aquatic ecosystems and energy flow. Classification of organisms into functional groups using a method that combines taxonomic assessments with direct functional measurements is very effective in understanding their interactions with the environment. Our objective was to determine the seasonal changes of zooplankton in Lake Yeniçağa using zooplankton functional groups. A total of 19 zooplankton species were identified in the lake and classified into six functional groups. Medium-sized cladoceran and copepod carnivorous feeders (MCC) accounted for 45.74% of all functional groups and were the dominant group in the lake. Throughout the year, medium and large zooplankton generally dominated in the lake, with smaller functional groups briefly dominating in spring and autumn. Statistical analysis indicates that medium-sized cladoceran and copepod filter feeders (MCF) and large-sized cladoceran and copepod filter feeders (LCF) showed a positive relationship with Secchi depth and a negative relationship with chlorophyll a. Other groups exhibited relatively lower correlations with environmental parameters. It can be concluded that the observed seasonal changes in these groups are affected not only by environmental parameters, but also by the availability of food resources.
EN
The trophic status of the Berdan River Basin was determined using univariate and multivariate classification tools. The results indicated that the water quality/trophic status of a downstream section of the Berdan River was characterized as “poor/eutrophic” due to anthropogenic inputs from agricultural, industrial and domestic wastewater discharges. Strong and positive correlations between TRIX values and concentrations of eutrophication parameters suggest that nutrient enrichment of water in the Berdan River during its flow will result in further eutrophication in the coastal region of the NE Mediterranean Sea. Therefore, the trophic and pollution status of the Berdan River, as well as other regional rivers flowing into the coastal area of the NE Mediterranean Sea should be monitored to develop action plans and sustainable management of eutrophication in regional rivers and the oligotrophic Mediterranean Sea.
EN
The incidence of cyanobacterial blooms in reservoirs intended for human supply represents a serious health risk due to the ability of these organisms to produce cyanotoxins. The study aimed to collect and summarize information related to variables associated with eutrophication of water sources of the Sorocaba River basin (São Paulo, Brazil). The objective was to assess the occurrence of cyanotoxins in treated water supplied to approximately 800,000 people. The study analyzed data from different abstraction, treatment, and distribution stations, emphasizing the supply from the Itupararanga and Ipanema dams, as well as the Sorocaba River. Data were obtained from the Drinking Water Quality Surveillance Information System (SISAGUA), the Autonomous Water and Sewage Service (SAAE), and the Environmental Company of the State of São Paulo (CETESB). A total of 4719 data points for cyanobacteria, chlorophyll-a, and cyanotoxins were analyzed between 2014 and 2021. The results indicate a deterioration in the trophic state of the Sorocaba River and the Itupararanga Dam, revealing a correlation between cyanobacteria and saxitoxins, with a predominance of the genus Raphidiopsis. A microcystin concentration of 0.40 µg l-1 was recorded at the Itupararanga Dam in treated water.
EN
To develop an oxygen indicator for the eastern part of the Gulf of Finland (EGOF), a dataset covering 1900–2021 was compiled. The analysis revealed a long-term declining trend in dissolved oxygen concentrations in the EGOF deep layer of 0.022 mg L–1 a–1 and multi-decadal variations associated with the observed changes in hydrographic conditions. About 27% of the decline in oxygen concentrations for 1900–2021 and 40% for 1990–2021 can be explained by the decrease in solubility due to the temperature increase and changes in hydrographic conditions. The water volume and bottom area under low oxygen conditions in 2016–2021, characterized by dissolved oxygen concentrations <= 6 mg L–1, have increased, compared to the selected reference period with almost no human impact in the 1920s–1950s, from 9.8 km3 to 78.0 km3 (from 2.6% to 20.9% of the EGOF total volume) and from 1190 km2 to 4950 km2 (from 13.4% to 56.0% of the EGOF total area), respectively. The environmental status of the EGOF was assessed as not good based on the introduced oxygen indicator. We conclude that, in the long-term, low oxygen conditions have expanded mostly due to the excess load and accumulation of nutrients in the system and temperature-related changes in biogeochemical processes and fluxes. However, on a decadal scale, changes in hydrographic conditions, i.e. stratification and mixing, can significantly impact the sub-surface oxygen conditions in the EGOF and similar estuarine basins.
EN
To fill the knowledge gap on the functioning of the river-lake system during the modernisation of the weir, an analysis of the variability of selected physico-chemical indicators was carried out. In the parameter analysis, particular emphasis was placed on phosphorus (P) and orthophosphate(V) (OP) content in the hydrological year 2022 and water quality was compared before, during and after the maintenance work on the discharge weir. Physicochemical parameters were analysed monthly at four stations. Concentrations of P and OP increased significantly as a result of the refurbishment works at the measurement point located downstream of the weir (P4), which contributed to the determination of a statistically significant change point. At the same time, when high P and OP contents were observed, high electrolytic conductivity and ammonium nitrogen in water were also recorded. The content of P and OP indicators was further reduced, but their content was still several times higher than before the renovation. The renovation of the weir below Lake Jeziory Wielkie contributed to a significant deterioration of water quality in the river-lake system. Due to the nature of this system, this was of great importance for the downstream reservoirs. The statistical analysis showed that the renovation of the weir below Lake Jeziory Wielkie contributed to a significant deterioration of water quality in the river-lake system.
EN
The aim of the study was to determine the causes of eutrophication in small urban water reservoirs located in the UMCS Botanical Garden in Lublin, supplied via surface and groundwater. The research (hydrological, hydrobiological, and hydrochemical), which included both field and laboratory work, was conducted during the growing season in the years 2022-2023. These ponds are fed by waters from the Czechówka River and, to a lesser extent, by groundwater (seepage). Both river and groundwater are characterised by high concentrations of mineral forms of nitrogen and phosphorus, ranging from 1.49 to 12.0 mg N∙dm-3 and 0.07 to 0.21 mg P∙dm-3, respectively. This contributes to the intensive development of phytoplankton, especially during the summer period, with diatoms dominating the phytoplankton structure. The trophic state of the ponds ranges from eutrophic to hypertrophic. The study showed that the high degree of eutrophication was due to the load of nutrients delivered by the waters of the Czechówka River. Despite having several times higher concentrations of mineral and total nitrogen than in the river water, the spring water feeding the ponds had a negligible impact on the quality of the pond water due to low flow rate (<0.5 dm3 ∙s-1). Therefore, the construction of urban ponds as part of green-blue infrastructure should consider the possibility of reducing nutrients through biogeochemical barriers and suspended sedimentation. It is also advisable to partially shade the water surface by planting trees in the shoreline zone to limit water heating and phytoplankton development.
EN
The article strives to determine the allowable content of nutrients in the wastewater that is being discharged into a reservoir, with the end goal of minimizing the risk of eutrophication. It was noted that the methodology currently used in Ukraine and most European countries to control pollutant discharge in wastewater is designed to simply not exceed the permissible pollution level in natural water based on sanitary indicators, which does not guarantee the absence of the eutrophication risk to the water bodies. The article describes a developed method for determining the allowable composition of wastewater based on biogenic indicators. The proposed method takes into account the consecutive transformation of nutrients, the probabilistic nature of the factors that determine the quality of water in water bodies, as well as the cost of purifying wastewater from various pollutants. The problem was considered for the case of wastewater discharge into a reservoir through a watercourse. This research is a practical scientific basis for further improving the methodology for standardization of the wastewater composition in order to protect water bodies from eutrophication.
EN
Coastal waters are currently receiving anthropogenic impacts from the mainland that caused the natural conditions to change to higher nutrient content. This study was conducted to examine the spatial and temporal dynamics of trophic status and how zone location and rainfall category affect the distribution of trophic status. Water quality data were collected for 6 months with different rainfall intensities at 16 observation stations. Trophic status was determined using the TRIX index which combines biological, physical, and chemical water variables. Rainfall had no significant effect on the TRIX index with a p-value of 0.223 (> 0.05), but the distance from the land had a significant effect with a p-value of (< 2e-16). In coastal waters in the 1st zone, the average TRIX value was 5.93 ± 0.23 (high trophic status/eutrophy that tends to be very high/hypertrophy), in the 2nd zone was 5.49 ± 0.21 (high trophic status/moderate trophy), in the 3rd zone was 5.23 ± 0.25 (high trophic status/eutrophy that is slightly low) and in the 4th zone was 4.47 ± 0.47 (moderate trophic status/mesotrophy). Based on PCA analysis and correlation for water quality data, Index TRIX had a strong positive correlation with phosphate (0.92), TSS (0.91), chlorophyll-a (0.089), temperature (0.88), nitrate (0.83), and moderate positive correlation with turbidity (0.68). In addition, the TRIX index had a strong negative correlation with salinity (-0.85), a moderate negative correlation with TDS (-0.77) and DO (-0.62), and a weak correlation with pH (-0.09). There has been eutrophication in coastal areas, especially in the near shoreline zone and tends to decrease at more distant locations. It is necessary to manage anthropogenic waste based on quality standards to ensure that coastal waters are healthy and support sustainable ecosystems.
PL
Przedstawiono wyniki analiz wybranych parametrów fizykochemicznych ścieków komunalnych z Zakładu Oczyszczania Ścieków Płaszów. Omówiono zjawisko eutrofizacji oraz pierwiastki biogenne. W części badawczej skupiono się na analizie bioprzyswajalnych form azotu oraz fosforu w ściekach. Ponadto porównano właściwości fizykochemiczne ścieków surowych i oczyszczonych biologicznie oraz oceniono skuteczność systemu oczyszczania ścieków w Płaszowie.
EN
The phys. chem. parameters of municipal sewage from the Płaszów Wastewater Treatment Plant were analyzed, such as the content of bioavailable forms of N and P, total suspended solids, BOD5, COD and pH. The phys. chem. properties of raw and biologically treated sewage were compared and the effectiveness of sewage treatment in Płaszów was assessed. During the analyzed period, the av. efficiency of removing the tested pollutants from sewage was high and, in most cases, exceeded 94%
EN
Nitrogen load is crucial for its application in various fields such as agriculture and improving water quality control for authorities responsible for establishing agricultural policies in the area. The calculation of nitrogen load using existing equations is not applicable for all types of rivers, thus requiring the development of a new equation that can be applied to lakes and rivers in the Biebrza river catchment. To determine the new equation, extensive mapping of the catchment area was conducted, which was adjusted to precipitation and runoff in the area, allowing the observed results to be compared. Based on several analyses, the new equation has better accuracy, RMSE of the new model-based estimation decreased by 65.9% in 2005–2015 and 62.2% in 2016–2021 for river and 92% in 2008–2019 and 95% in 2020–2021 for lakes. Therefore, the application of the new calibrated empirical model provides results close to the real values and it can be used in the Biebrza river basin to simulate the total nitrogen runoff.
EN
In this study, dissolved nutrients concentrations weremeasured monthly at downstream points of the tworegional rivers (the Berdan and Göksu rivers) flowing into the Cilician Basin of the North-eastern (NE) Mediterranean Sea. The dissolved nutrients data obtained between September2021 and August 2022 were used to determine riverinenutrient fluxes. This study showed that spatial and temporalvariations were recorded in nutrients concentrations of thetwo regional rivers with the maximum values consistentlyrecorded in the Berdan River having lower volume fluxes.The annual nutrient inputs of the two regional riversindicated that higher amounts of dissolved nutrients werecarried by the Göksu River due to its higher volume fluxrate. The calculated molar ratios from total nitrogen (TN)and phosphorus (TP) fluxes ranged from 13 in the GöksuRiver to 22 in the Berdan River. The higher TN/TP molar ratiocompared to the classic Redfield Ratio of N/P in the BerdanRiver is very likely to modify nutrient dynamics leadingto further eutrophication in the shelf waters of the NE Mediterranean Sea.
EN
The article analyzes the impact of nutrients (nitrates and phosphates) supplied from the land on the waters of the Puck Lagoon (Gdańsk Basin, southern Baltic). The study is based on the numerical modelling. The model data was verified by comparison with the in situ measurement data. The spatial and temporal variability of the concentrations of nitrate, phosphate, and chlorophyll a were analyzed. We came to the conclusion that the load of nutrients deposited from the land side to the waters of the Puck Lagoon is relatively small (but not negligible compared to the Vistula River). However, even when a little runoff enters the reservoir with a very limited water exchange, like the Puck Lagoon, there are periods when riverine nutrients load significantly affects the functioning of the ecosystem.
EN
The objective of the study was to trace the variability of the hydrochemical conditions in three lakes of the West Pomeranian Voivodeship (Poland) - Starzyca, Maszewskie and Nowogardzkie in the annual cycle. The research was done in 2018-2019, and samples for analysis were collected 4 times a year. All analyses were performed applying standard methods. Such hydrochemical indices were determined as dissolved oxygen, chemical oxygen demand, content of orthophosphates, total phosphorus, nitrite, nitrate, ammonium, chlorophyll a and iron. The study showed that all lakes in the research cycle were characterised by a polymictic type of water mixing, and the trophic level, based on the adopted criteria, indicated advanced eutrophy, which may also be caused by anthropogenic pressure. Oxygen conditions characterised by deoxidation of the waters in the bottom layer in the spring and summer seasons, and clear oxygenation in the surface water layer (in Lake Maszewskie reaching even 188.5% in the spring) confirm the significant advancement of the eutrophication process. The supply of phosphorus and nitrogen in spring from pelagic waters in the waters of the examined lakes influences concentrations of chlorophyll a in the summer. The influence of “internal supply” (bottom waters and bottom sediments) on the amount of nutrients available for autotrophs is clearly visible in the analysed lakes - an increase in nitrogen and mineral phosphorus concentrations in relation to surface waters was observed in the bottom layer.
EN
Microcystis blooms and the related toxin known as microcystin-LR (MC-LR) put the safety of human water consumption and global irrigation practices in jeopardy. MC-LR is widely distributed in various environments, including water, sediments, plants, and other aquatic organisms. The use of water-containing microcystins for agricultural purposes may have to be restricted despite the limited availability of clean water resources. Accordingly, the present work aimed to determine the MC-LR concentrations and recognize the environmental parameters that initiate the growth of toxic cyanobacteria and MC-LR occurrence in 20 irrigation ponds in the Jordan Valley area. The irrigation ponds studied were found in a hypereutrophic condition, with high levels of N:P ratio and low transparency. These cause inseparable effects such as cyanobacterial bloom and MC-LR occurrence. The investigated ponds were classified as hypereutrophic according to General Quality Index (GQI), with two different types of algae covering the surface. The first was the Lemna sp. or duckweeds (Family Araceae) which are free-floating masses, and the second was the cyanobacteria algal bloom. Unpaired t-tests were performed and showed that the concentrations of MC-LR in pond water abundant with cyanobacteria algal bloom in September 2021 were significantly higher (P = 0.7906) than in June for the same year (0.3022 ± 0.0444 and 0.1048 ± 0.0171 ppb, respectively). Two methods for extracting MC-LR were used and showed a significant difference in MC-LR concentration in ponds with an abundance of cyanobacteria algal blooms (0.2273 ± 0.0356 ppb) compared to the ponds with an abundance of Lemna sp. or duckweeds collected in June 2021 (0.1048 ± 0.0171 ppb). Despite all of the efforts made by Jordan Valley farmers to prevent or limit the mass growth of cyanobacteria and its consequences for the eutrophication process in their irrigation ponds through the use of fish breading and chemicals such as copper sulfate, this environmental problem is still harming their crops and irrigation methods and requires immediate government assistance.
EN
Physicochemical parameters play a significant role in determining phytoplankton structure and dynamics in the lake. The present study investigated the phytoplankton dynamics and their correlation with physicochemical parameters in the dry season of Maninjau Lake. The parameters measured, including temperature, transparency, pH, DO, TN, and TP concentrations, were collected from seven lake locations, i.e., in the middle of the lake, near domestic, hydropower, endemic fisheries, and aquaculture cage areas, and inlet-outlet rivers. Phytoplankton samples were collected from the middle of the lake, near domestic and aquaculture cage areas. TSI analysis shows that Maninjau Lake was hypereutrophic, with an average TSI of 101.15. The phytoplankton community comprises six classes and 22 species dominated by Microcystis aeroginosa and Synedra acus. Bacillariophyceae had the highest phytoplankton concentration, while Cyanophyceae had the highest density. The diversity and equity index of the phytoplankton community structure were low and less evenly distributed, confirming that the lake was hypereutrophic. The highest diversity index was found in the middle of the lake or the most profound part, while the lowest was near the domestic area. Among the physicochemical parameters, transparency has a strong correlation with dominant phytoplankton.
EN
This study employed a laboratory-scale continuous upflow bio-contact oxidation reactor to treat 50 L/day of municipal wastewater in Al Rumaitha City, located north of Al Muthanaa Province in Iraq. The reactor configuration consisted of two anoxic-aerobic reactors nested inside each other, with a 1:3 volume ratio of anoxic to aerobic zones. Both the anoxic and aerobic reactors were loaded with K1 bio-media, filling them to 50% capacity for fixing and preserving the biomass. The reactors were operated in a mode that achieved full nitrification-denitrification without any sludge return, relying solely on internal recycling from the aerobic to the anoxic reactor. After biofilm formation on the carriers, three distinct hydraulic retention times (HRTs) were investigated – ranging from 24 to 12 hours – to evaluate their impact on removing biological nutrients from municipal sewage. In this operational approach, the preferred internal recycle ratio and gas/water ratio for effective nitrogen removal were a complete feed rate recycle of 100% and a ratio of 1:5, respectively. The experiment results highlighted that a 24-hour hydraulic retention time was most suitable for the simultaneous removal of organic carbon (COD) and nutrients. During this period, average removal efficiencies were found to be 93.51% for COD, 94.50% for ammonium (NH4+), 60.98% for total nitrogen (TN), and 67.57% for total phosphorus (TP). Furthermore, the aerobic bio-contact oxidation reactors maintained an average dissolved oxygen (DO) concentration of 4.89 mg/L. In contrast, the anoxic bio- contact oxidation reactors exhibited a lower average DO concentration of 0.38 mg/L.
PL
Pływające wyspy hydrofitowe są coraz częściej spotykanym elementem krajobrazu - szczególnie na otwartych akwenach miejskich. Posiadają walory estetyczne, są rozwiązaniami opartymi na naturze, poprawiają mikroklimat, a przede wszystkim pełnią funkcję oczyszczającą. Do tej pory jednak nie udało się precyzyjnie sklasyfikować rozwiązań pływających wysp hydrofitowych (z ang. floating treatment islands) w nomenklaturze polskiej. Brakuje również specyficznych wytycznych do ich projektowania. W niniejszym artykule podjęto się wyjaśnienia idei metody, klasyfikacji systemu pływających wysp hydrofitowych, omówiono podstawowe mechanizmy usuwania zanieczyszczeń oraz wybrane zagadnienia projektowe. Praca powstała w wyniku realizacji projektu Preludium 18 [2019/35/N/ST8/01134].
EN
The popularity and presence of floating treatment istalnds in the landscape is increasing rapidly, particularly on open urban reservoirs. They are distinguished by their aesthetic value, belong to nature-based solutions, improve the microclimate, and, most importantly, have a cleansing function. However, in the Polish nomenclature, floating treatment islands solutions have yet to be precisely classified. There are also no specific design guidelines. This article attempts to explain the method’s concept, classify the system of Floating Treatment Wetlands, discuss the basic pollutant removal mechanisms, and discuss selected design issues. The work was created as a result of the Preludium 18 project [2019/35/N/ST8/01134].
PL
Za zanieczyszczenie wód substancjami biogennymi - azotem i fosforem - w dużej mierze odpowiadają rolnictwo i gospodarka ściekowa. By ograniczyć wpływ tych sektorów na stan wód, regularnie prowadzone są przeglądy i aktualizacje programów i polityk w tym zakresie, zarówno na poziomie Unii Europejskiej, jak i krajowym, oraz realizowany jest szereg działań i inwestycji. Z uwagi na dynamiczny rozwój przemysłu i produkcji w ostatnich dekadach problemem dla wód stały się nowe rodzaje zanieczyszczeń. Do walki z ich ograniczeniem służyć ma szeroki wachlarz nowych rozwiązań proponowanych w projekcie znowelizowanej dyrektywy ściekowej.
EN
Agriculture and wastewater management are among the main sources of pollution of waters with biogenic substances such as nitrogen and phosphorus. In order to reduce the impact of these sectors on the status of waters, regular revisions and updates of related programmes and policies are carried out, both on EU and national levels, followed by a series of actions and investments. Due to the dynamic development of industry and production over recent decades, waters now face new types of pollutions. The draft revision of the wastewater directive - the so-called transformation - includes a wide range of new solutions to reduce them.
PL
Dobry stan ekosystemów wodnych ma kluczowe znaczenie dla życia i zdrowia ludzi oraz dla rozwoju gospodarki. Jedną z przyczyn degradacji tych ekosystemów są zanieczyszczenia biogenami, takimi jak azot i fosfor, przyczyniające się do eutrofizacji, a jednym z głównych źródeł tych zanieczyszczeń jest rolnictwo. W artykule przedstawiono zmiany wprowadzone w aktualizacji „Programu działań mających na celu zmniejszenie zanieczyszczenia wód azotanami pochodzącymi ze źródeł rolniczych oraz zapobieganie dalszemu zanieczyszczeniu” w kontekście kierunków polityki Unii Europejskiej i zobowiązań wynikających ze strategii i inicjatyw Europejskiego Zielonego Ładu, takich jak: unijna strategia na rzecz bioróżnorodności 2030, nowy plan działania dotyczący gospodarki o obiegu zamkniętym czy strategia „od pola do stołu”. Artykuł opisuje znaczenie zrównoważonego rolnictwa dla ochrony wód i ograniczenia zjawiska eutrofizacji.
EN
Good status of water ecosystems is of key importance to the life and health of people, as well as to the economic development. One of the reasons behind degradation of these ecosystems is biogenic pollution, including nitrogen and phosphorus, contributing to eutrophication; one of the main sources of this pollution is agriculture. The article presents modifications introduced to the updated "Programme of measures to reduce water pollution with nitrates from agricultural sources and prevention of further pollution" in the context of EU policy directions and obligations resulting from the strategy and initiatives of the European Green Deal, such as: EU Biodiversity Strategy for 2030, new Circular Economy Action Plan, or Farm to Fork Strategy. The article describes the importance of sustainable agriculture for the protection of waters and reduction of the eutrophication phenomenon.
EN
The article is devoted to the disclosure of the effect on the vital activity of cyanobacteria by changes in the nutrients in the chemical composition of artificial aquatic biotopes. The research results allowed us to establish that the dissolution of complex mineral fertilizer (nitrogen, phosphorus and potassium) in the range of up to 10 g/L contributes to the active development of cyanobacteria, which is accompanied by complete binding of mineral additives and absorption of oxygen. The addition of fertilizers in the amount of more than 1 g/L contributes to a sharp increase in the growth rate of the cyanobacteria population, which provokes the conditions for the blooming of the solutions. Enrichment of the nutritive base of biotopes ensures rapid growth of biocenosis and accelerated consumption of dissolved substances. The recorded average absorption rate of phosphorus reached more than 17 g/(L·day), and nitrogen – 30 g/(L·day). The formation of sediment and foam in the test vessels was associated with the depletion of nutrients and the death of hydrobionts. This phenomenon can serve as an indicator of oxygen decrease in the water. The results of the experiment confirmed the ability of cyanobacteria to transform nitrogen and phosphorus dissolved in water into bound organic forms with high intensity. This opens up the prospect of creating biological methods and means of wastewater demineralization.
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