Water quality assessment of aquatic ecosystems using ecological criteria – case study in Bulgaria (original) (raw)
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2021
Surface water samples in Ogosta River, Bulgaria and wastewater samples at the inlet and outlet of WWTP–Montana were tested for the traditional parameters and ecotoxicological effect. The river and Dam surface waters comply with category A1 of Directive 75/440/EEC for pH, EC, COD, TSS, NO3, Cl, SO4, B, Ba, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se, V and Zn; with category A2 for BOD5, NH4–N and Fe; and with category A3 for TNb and As. The average annual concentrations of Al, Cr (III), Cr (VI) and U are lower than the set limits in the Water Framework Directive. Arsenic concentration in all the samples exceeds the maximum allowed concentration, a results from natural processes. All the levels of the studied parameters in the outlet wastewater samples are lower than the limits, set in Directive 91/271/EEC and in the complex permit of the WWTP. The results of the biotest Phytotoxkit FTM show low ecotoxicity of the water samples. Optimization of the sample pretreatment prior to this ecotoxicologica...
SIMI 2018, 2018
The present study assessed the spatial water quality variation of physical and chemical variables. The water quality data were collected during May 2018 from several sampling stations distributed between Ceatal Izmail and Sf. Gheorghe branch and up to the Dunavat Canal, as well as Razim and Golovita lakes. The sampling stations were selected on the basis of their contamination susceptibility, i.e., the station located along the above-mentioned sector of the Danube River were tended to be more impaired by the human related activities. Instead, the stations downstream to the Danube River (the lower course-deltaic area), i.e., Razim and Golovita lakes were supposed to be less impaired by the urban and rural contamination. The investigated sites are of particular interest since they belong to the Danube Delta Biosphere Reserve (DDBR). The following water quality parameters were measured: depth (m), temperature (o C), pH (units), dissolved oxygen content (mg/l), electrical conductivity (µS/cm), total dissolved solids (mg/l), sulphates (mg/l), nitrite-nitrogen (mg/l), nitrate-nitrogen (mg/l), orthophosphates (mg/l), chlorophyll "a" (µg/l), turbidity (NTU), total suspended solids (mg/l), Secchi visibility (m), silica content (mg/l) etc. Overall, the results indicated that some variables presented comparable values that have not exceeded those limits recommended by the reference standard. Instead, the fall in the quality of water (any abnormal values encountered in a few situations) may be related to a wide range of local natural environmental circumstances, as well as anthropic factors. The outcomes obtained from the present study shall be useful in the future environmental assessment of the aquatic ecosystems in DDBR area.
Environmental monitoring of Novoselska River, Bulgaria
Environmental monitoring of Novoselska River, Bulgaria, 2017
This current study provides some information about the environmental parameters of the Novoselska River`s environment in the village of Slokoshtitsa, Kyustendil. The water of the Novoselska River is relatively clean as there were no major anomalies in the measured parameters. At the entrance of the river in the village of Slokoshtitsa the river is cleaner than at the exit of the village, especially after the dumpsites. Although the dumpsites are small in size, it is clear from the survey that there is pollution around and after them. The values of all studied parameters increased in these areas. Dirty water with residues of detergents and disinfectants from the village flows into the river, the dirty water has presence of cyanuric acid in it. The covered portion of the river has a temperature different from that of the natural part of the river, during the cold months it is higher, and in the warmer months it is lower than the temperature of the environment. This can negatively affect the ecosystem of the river. Water`s hardness is medium to high, which means that after the construction of the dam, it must pass through the softener before it is available for drinking or for agricultural water. The water at the time of the testing is not suitable for systemic watering of the crops and watering of livestock due to high concentrations of cyanuric acid and copper. A constant environmental monitoring of the Novoselska River is necessary in order to collect data about the river before and after the construction of the Kyustendil dam.
Heavy metals are widespread pollutants with significant environment risk due to high toxicity and clear tendency for accumulation in different matrices – soils, sediments, biota. The main research objective of this work is to assess the impact of heavy metal pollution on key structural and functional parameters of microbial communities in sediments of river-dam sequence of small hydropower cascade Middle Iskar, Bulgaria. The content of heavy metals (As, Cd, Cu, Hg, Pb, Zn) was measured during the low water summer periods of 2012, 2013 and 2014. The evaluation of site quality and heavy metal pollution was done by use of one integrated index-Pollution Load Index and it was compared to total count of sediment microbiota and count of coliform bacteria, also with total dehydrogenase activity and index of phosphatase activity. The assessment of heavy metal pollution in river-dam sequence of cascade indicates the higher metal concentrations and high Pollution Load Index in dam sediments. At low level of pollution in river sites, the both structural and functional microbial parameters react to local variations of heavy metal concentrations and high negative correlation (r=-0.8÷-0.9) exists between variables. But in dam sites, the microbial community is more resistant to pollution and structural parameters react conservatively with long reaction time. The enzyme activities are more adaptive and sensitive indicators for different level of environmental impact in this case. The complex phosphatase and dehydrogenase activities have a high potential to be used as reliable parameters for precise assessment of hazardous sediment pollution in complicated ecological situations with cumulative impacts.
Environmental Science: Processes & Impacts, 2014
In order to maintain and improve the water quality in European rivers, the Water Framework Directive (WFD) requires an integrated approach for assessing water quality in a river basin. Although the WFD aims at a holistic understanding of ecosystem functioning, it does not explicitly establish cause-effect relationships between stressors and changes in aquatic communities. To overcome this limitation, the present study combines the typical WFD physicochemical and biological approaches with an ecotoxicological approach.
Ecological Status Assessment of Batova River (Bulgaria)
2019
The Batova Valley is protected in the sense of the requirements of the Habitats and Birds Directives and the Biodiversity Act. European environmental agency developed in the 2000 year Directive 2000/60/EC for a mutual strategy of European Council countries, for prevention and protection of waters. Criteria for assessment of surface water bodies based on hydromorphological, phisico-chemical and biological quality elemets for characterization of ecological state had addopted. In this study, two points of water collection sampling of Batova River were chosen: before and after Batovo Village, in order to assess the impact of the village on the quality of waters and the status of aquatic ecosystems. Physico-chemical parameters (pH, conductivity, dissolved oxygen, biochemical oxygen demand, ammonium, nitrate, phosphate ions) were measured and biological/benthological samples were taken. According phisico-chemical quality elements Batova River was classifided as moderate status and “not ac...
Ecological Monitoring of Danube water Quality in Budapest Region
American Journal of Environmental Sciences
Problem statement: Serious health problems and other economic costs related to water treatment, remediation and locating a new water supply, become an evidence of water pollution caused by human activities. The main problems of the Danube River basin are associated with nutrients, organic pollution and hazardous pollutants. The aim of the study is to assess the surface water of the Danube in Budapest for sustainability of human and environment health. Approach: The monitoring assessment of comparative studies was carried out in June of 1998, 2005 and 2010 using the Hungarian standard methods. The samples were collected in sterile dark bottles from three different zones in Budapest. Results: The results demonstrated that dissolved organic carbon content, nutrient pollution (total N and P), bacteriological parameters and chlorophyll-a content were higher in 2005 than in 1998 and 2010. The results indicated that the bacteriological assessments and bacterial populations were low in 1998 in comparison with the results of 2010. In 2005, investigations illustrate the high fecal pollution. The data showed no significant differences between temperature, pH and Electrical conductivity in 1998, 2005 and 2010. Conclusion/Recommendations: Monitoring of the water by physicochemical and bacteriological is essential to identify the aquatic ecosystem hazards.
Environmental monitoring of Dragovishtitsa River, Bulgaria
Environmental monitoring of Dragovishtitsa River, Bulgaria, 2015
General aim of the study is collecting of data for the environment and the ecosystem of Dragovishtitsa River, Bulgaria and receiving of information for its influence on contamination of the Struma (Strimon) river. Samples are taken and measurements are done at intervals about 500 m along the river as well as the estuary at place of its entrance into the Struma river. By this way 50 points of measurements in Serbia and 50 points in Bulgaria were measured. The main conclusion of the study is that the water of Dragovishtitsa river responds to the type R3-Mountain river as almost all measured parameters are in normal range with few exemptions for Cyanuric acid and nitrate content. There were measured 45 parameters of the environment and most of them are result of natural processes. Only Cyanuric acid and nitrates are in relatively high range around the waste canals from human living in Serbia and agricultural farms in Bulgaria. Recommendation is to be taken attention on this kind of contaminator with relation of the governmental efforts for restoration of the population of the Brown trout fish into the river.
International Journal of Environmental Research and Public Health
This study aimed at investigating the distribution of heavy metals (HMs: Zn, Pb, Cd, Ni, Cr, and Cu) in the bottom sediments of 28 reservoirs covered area of Poland. The paper evaluates the pollution of sediments with HMs and their potential toxic effects on aquatic organisms and human health on the basis of results provided by the Chief Inspectorate of Environmental Protection in Poland. The average concentrations of HMs in the bottom sediments of the reservoirs were as follows: Cd < Ni < Cr < Cu < Pb < Zn. (0.187, 7.30, 7.74, 10.62, 12.47, and 52.67 mg∙dm−3). The pollution load index values were from 0.05 to 2.45. They indicate contamination of the bottom sediments in seven reservoirs. The contamination-factor values suggest pollution with individual HMs in 19 reservoirs, primarily Cr, Ni, Cu, and Pb. The analysis showed that only two reservoirs had the potential for toxic effects on aquatic organisms due to high concentrations of Cd and Pb. The hazard index values ...