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Marina Valentukeviciene
Faculty of Environmental Engineering, Vilnius Gediminas Technical University, Vilnius LT10223, Lithuania

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Journal article
Published: 18 October 2020 in Symmetry
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When exposed to temperatures that are progressively and rapidly raised, large dimension fibre cement boards tend to crack. This occurrence is analysed and explained for a specific issue of asymmetric growth of a curvilinear crack in high temperatures. This phenomenon occurred while performing Single Burning Item (SBI) experiments at fire loads which are higher than those used in countries of the European Union, which better reflect fire events that may occur in high-rise buildings. In such conditions, fibre cement boards crack, allowing the fire to reach the thermal insulating material which then combusts, thereby helping to spread the conflagration to upper floors. This experiment investigated the temperatures at which fibre cement boards crack, and why. Thermal analysis methods and thermogravimetric experiments were conducted on the fibre boards, followed by x-ray phase analysis investigations. During this phase, x-ray structural analysis was performed while the fibre cement was exposed to temperatures of 1000 °C. The article also presents ongoing change results when heating only composite fibre-cement board materials; phase changes that take place in high temperatures are discussed.

ACS Style

Tomas Veliseicik; Ramune Zurauskiene; Marina Valentukeviciene. Determining the Impact of High Temperature Fire Conditions on Fibre Cement Boards Using Thermogravimetric Analysis. Symmetry 2020, 12, 1717 .

AMA Style

Tomas Veliseicik, Ramune Zurauskiene, Marina Valentukeviciene. Determining the Impact of High Temperature Fire Conditions on Fibre Cement Boards Using Thermogravimetric Analysis. Symmetry. 2020; 12 (10):1717.

Chicago/Turabian Style

Tomas Veliseicik; Ramune Zurauskiene; Marina Valentukeviciene. 2020. "Determining the Impact of High Temperature Fire Conditions on Fibre Cement Boards Using Thermogravimetric Analysis." Symmetry 12, no. 10: 1717.

Journal article
Published: 03 June 2020 in Materials
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Concrete itself, and issues relating to the recycling and management of reinforced concrete waste, are highly relevant, especially when urban expansion is being achieved by increased building construction volumes. This research investigates concrete waste and its (re)usage possibilities and resolves several major issues related to the question of how natural materials can be replaced by compounds made from concrete waste, thereby saving natural resources. The experiment was carried out using concrete mixtures, which were combined with natural aggregates and crushed concrete waste (fraction 4/16). The resulting mix of concrete was achieved using natural aggregates, thus replacing natural aggregates with waste, which had partially and fully replaced bulky aggregates with crushed concrete waste. The main aim of the investigation was to investigate how aggregates made from crushed concrete waste impact the properties of concrete. The exothermic effect on the concrete mixture during the hardening process was investigated. Furthermore, a macrostructural analysis of hardened concrete was conducted using scanned sample images; the adhesion zone between newly formed concrete stone and aggregates derived from natural rock from crushed concrete waste was investigated. Using an electron microscope to observe aggregate from crushed concrete waste and the contact zone of hardened cement stone revealed that the aggregate from waste adheres poorly with hardened cement stone. Furthermore, both the mechanical properties of new, hardened concrete and determined resistance to frost indicators are weak. Concrete density and compression strength decreased (by up to 8% and up to 18%, respectively), and absorption increased almost twofold due to aggregates derived from crushed concrete waste, since their cleavage strength indicator was twice as high, while water absorption was four times higher than that of natural aggregate. The results indicate that recycled concrete obtained from demolished buildings is environmentally sustainable and can be recommended for lower quality concrete for use in related engineering projects.

ACS Style

Ramunė Žurauskienė; Marina Valentukevičienė. Experimental Research on Quality Parameters of Recycled Concrete. Materials 2020, 13, 2538 .

AMA Style

Ramunė Žurauskienė, Marina Valentukevičienė. Experimental Research on Quality Parameters of Recycled Concrete. Materials. 2020; 13 (11):2538.

Chicago/Turabian Style

Ramunė Žurauskienė; Marina Valentukevičienė. 2020. "Experimental Research on Quality Parameters of Recycled Concrete." Materials 13, no. 11: 2538.

Journal article
Published: 01 March 2019 in Ecological Chemistry and Engineering S
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Fluoride removal from aqueous solutions was studied using nanofiltration and sorption techniques which have always been best key ways to deal with water contaminated by fluoride. In this presented work, we were firstly interested on fluoridated rejected water overcoming the drawback of RO membrane process of groundwater treatment plant in Baltic region (Kretinga, Lithuania). Opoka sorbent has shown effective results of fluoride sorption with efficiency higher than 77 %. In order to understand the sorption phenomenon and to validate the results obtained, we have applied experimental data on Freundlich and Langmuir isotherms which allow us to determine isotherms parameters (KF; 1/n and KL; qmax) and to confirm the experiment. Because of the unacceptable tariff of drinking water treated by RO, defluoridation with nanofiltration method is proposed in this study as a solution which can replace reverse osmosis technique. For that, tests of nanofiltration for fluoride removal were carried out at laboratory scale by using nanofiltration flat sheet membranes (NF270 and NF90).

ACS Style

Marina Valentukeviciene; Ramune Zurauskiene; Youssef Amine Boussouga. Fluoride Removal from Groundwater by Technological Process Optimization. Ecological Chemistry and Engineering S 2019, 26, 133 -147.

AMA Style

Marina Valentukeviciene, Ramune Zurauskiene, Youssef Amine Boussouga. Fluoride Removal from Groundwater by Technological Process Optimization. Ecological Chemistry and Engineering S. 2019; 26 (1):133-147.

Chicago/Turabian Style

Marina Valentukeviciene; Ramune Zurauskiene; Youssef Amine Boussouga. 2019. "Fluoride Removal from Groundwater by Technological Process Optimization." Ecological Chemistry and Engineering S 26, no. 1: 133-147.

Journal article
Published: 16 November 2018 in Sustainability
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The trans-boundary area between the Europe Union and other countries is highly susceptible to changes in water quality and variations in the potential pollution load that could influence its eco-systems significantly. The Neris (Viliya) River is one of the biggest surface water bodies in Lithuania and Belarus with an ecologically important area protected by international legislation. The study was aimed at evaluating the impacts of integrated pollution on water quality of the Neris River taking into account different storm-water flows and ecological scenarios. For this purpose, qualitative and quantitative statistical evaluation was set up and calculation was done; different integrated pollution loads of the catchment area were estimated. The evaluation considered a decrease in river discharge due to changes in the regional storm-water flow and technological development that should lead to the growing covered surface and a reduction in the untreated storm-water flows. The obtained results indicated that, in the case of storm-water treatment, the total nitrate and phosphate concentrations will decrease, while in the cases of changes in combined suspended solid, the concentration of nutrients will decrease. Thus, a trans-boundary storm-water treatment plant of the Viliya River is required as it should eliminate pollution accumulation and restore its acceptable environmental status. A coordinated international project for the entire catchment of the Neris (Viliya) River based on the specifications and requirements of the EU Water Framework Directive (EU 2000) should be developed and implemented. Subsequently, ecological river-use policies should be established at the international level, which should offer considerable perspectives for the sustainable development of the area.

ACS Style

Marina Valentukevičienė; Lina Bagdžiūnaitė-Litvinaitienė; Viktoras Chadyšas; Andrius Litvinaitis. Evaluating the Impacts of Integrated Pollution on Water Quality of the Trans-Boundary Neris (Viliya) River. Sustainability 2018, 10, 4239 .

AMA Style

Marina Valentukevičienė, Lina Bagdžiūnaitė-Litvinaitienė, Viktoras Chadyšas, Andrius Litvinaitis. Evaluating the Impacts of Integrated Pollution on Water Quality of the Trans-Boundary Neris (Viliya) River. Sustainability. 2018; 10 (11):4239.

Chicago/Turabian Style

Marina Valentukevičienė; Lina Bagdžiūnaitė-Litvinaitienė; Viktoras Chadyšas; Andrius Litvinaitis. 2018. "Evaluating the Impacts of Integrated Pollution on Water Quality of the Trans-Boundary Neris (Viliya) River." Sustainability 10, no. 11: 4239.

Journal article
Published: 18 May 2016 in Journal of Environmental Engineering and Landscape Management
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Wastewater treatment loadings with total nitrogen can increased by introducing fugate that is saturated with ammonium ions, generated when dewatering wastewater treatment sludge. In this article the possibility to reduce the concentration of ammonium ions in the fugate by the use of natural zeolite (Transcarpatian clinoptilolite) has been analysed. Lab-scale experiments were carried out with different particle sizes zeolite: 0.8–1.6 mm, 1.6–2.5 mm and 2.5–3.2 mm. At the first stage of the experiments, zeolite particles were mixed with fugate and left to settle until a 99% efficiency of ammonium ion removal was achieved. At the second stage, ammonium ions were removed from the fugate by filtering this liquid through zeolite where the 70–92% efficiency was achieved. Zeolite saturated with ammonium ions possibly can be used in agriculture as nitrogenous fertilizers. Obtained fertilizer grade of zeolite saturated with fugate can also be produced from the high ammonium nitrogen concentration side-streams separated from wastewater flow from sludge digestion processes.

ACS Style

Aušra Mažeikienė; Marina Valentukevičienė. REMOVAL OF AMMONIUM IONS FROM DIGESTED SLUDGE FUGATE BY USING NATURAL ZEOLITE. Journal of Environmental Engineering and Landscape Management 2016, 24, 176 -184.

AMA Style

Aušra Mažeikienė, Marina Valentukevičienė. REMOVAL OF AMMONIUM IONS FROM DIGESTED SLUDGE FUGATE BY USING NATURAL ZEOLITE. Journal of Environmental Engineering and Landscape Management. 2016; 24 (3):176-184.

Chicago/Turabian Style

Aušra Mažeikienė; Marina Valentukevičienė. 2016. "REMOVAL OF AMMONIUM IONS FROM DIGESTED SLUDGE FUGATE BY USING NATURAL ZEOLITE." Journal of Environmental Engineering and Landscape Management 24, no. 3: 176-184.

Conference paper
Published: 07 April 2016 in Proceedings of the 19th Conference for Junior Researchers „Science – Future of Lithuania“
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Straipsnyje išnagrinėta Vilnios upės dugno nuosėdų tarša sunkiaisiais metalais. Tiriamasis objektas yra Vilniuje, Vilnios upėje, 7 kilometrų ruože. Nagrinėta sunkiųjų metalų koncentracija upės dugno nuosėdose. Tyrimai atlikti abiejuose upės krantuose, atsižvelgiant į šalia esančius taršos objektus. Nuosėdų tyrimui naudotas rentgeno fluorescencinis spektrometras. Gauti rezultatai apdoroti ir palyginti su didžiausiomis leistinomis sunkiųjų metalų koncentracijomis (DLK) Lietuvos upėse. Nustatomos ėmimo vietos užterštumo kategorijos (laipsniai) pagal Zd rodiklį (HN 60:2004) taip įvertinant didžiausias taršos susitelkimo vietas. Tirtajame Vilnios upės ruože, viename mėginių paėmimo taške, yra nustatytas didelis suminis rodiklis (Zd), kuris siekia 118, o tai sudaro apie 9 % visų tirtųjų mėginių paėmimo vietų Vilnios upės tirtajame ruože.

ACS Style

Goda Semionovaitė; Gytautas Ignatavičius; Marina Valentukevičienė. UŽTERŠTUMO SUNKIAISIAIS METALAIS VILNIOS UPĖS DUGNO NUOSĖDŲ TYRIMAI. Proceedings of the 19th Conference for Junior Researchers „Science – Future of Lithuania“ 2016, 1 .

AMA Style

Goda Semionovaitė, Gytautas Ignatavičius, Marina Valentukevičienė. UŽTERŠTUMO SUNKIAISIAIS METALAIS VILNIOS UPĖS DUGNO NUOSĖDŲ TYRIMAI. Proceedings of the 19th Conference for Junior Researchers „Science – Future of Lithuania“. 2016; ():1.

Chicago/Turabian Style

Goda Semionovaitė; Gytautas Ignatavičius; Marina Valentukevičienė. 2016. "UŽTERŠTUMO SUNKIAISIAIS METALAIS VILNIOS UPĖS DUGNO NUOSĖDŲ TYRIMAI." Proceedings of the 19th Conference for Junior Researchers „Science – Future of Lithuania“ , no. : 1.

Journal article
Published: 16 March 2015 in Ekologija
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ACS Style

Marina Valentukevičienė; Gytautas Ignatavicius. Improvement of phosphorus removal in the wastewater treatment. Ekologija 2015, 60, 1 .

AMA Style

Marina Valentukevičienė, Gytautas Ignatavicius. Improvement of phosphorus removal in the wastewater treatment. Ekologija. 2015; 60 (4):1.

Chicago/Turabian Style

Marina Valentukevičienė; Gytautas Ignatavicius. 2015. "Improvement of phosphorus removal in the wastewater treatment." Ekologija 60, no. 4: 1.

Journal article
Published: 24 October 2014 in Mokslas - Lietuvos ateitis
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The article investigates the processes of removing suspended solids and ammonium ions from sludge liquor. Experimental research was carried out at the Water Management Department laboratory of Vilnius Gediminas Technical University applying an experimental bench made of filters equipped with the zeolites of a different fraction and other appliances. Laboratory testing looked at the use of natural sorbent zeolite for removing ammonium ions from sludge liquor mixing liquid with powdered zeolite and filtering through zeolite filter media. Research was carried out employing the particles of zeolite 1.0–1.5 mm; 2.0–2.5 mm; 2.5–3.15 mm in diameter. The highest efficiency of removing ammonium ions reached 76% and was obtained using zeolite particles 2.0–2.5 mm in diameter. Straipsnyje nagrinėjami skendinčiųjų medžiagų ir amonio jonų šalinimo iš dumblo skysčio procesai. Eksperimentiniai tyrimai buvo rengiami VGTU Vandentvarkos katedros laboratorijoje įrengtame eksperimentiniame stende, sudarytame iš filtrų, užpildytų skirtingos frakcijos ceolitų ir kitos įrangos. Laboratorinio tyrimo metu buvo nagrinėjama, kaip gamtinis sorbentas ceolitas naudojamas amonio jonams iš dumblo vandens šalinti, skystį maišant su ceolito milteliais ir filtruojant per ceolito užpildus. Tyrimai vykdyti naudojant 1,0–1,5 mm, 2,0–2,5 mm, 2,5–3,15 mm ceolito frakcijas. Šalinant amonio jonus iš dumblo skysčio, didžiausias efektyvumas, naudojant 2,0–2,5 mm frakcijos ceolitą, siekia 76 %.

ACS Style

Kasparas Gražinskas; Aušra Mažeikienė; Marina Valentukeviciene. EXPERIMENTAL RESEARCH ON REMOVING SUSPENDED SOLIDS AND AMMONIUM IONS FROM SLUDGE LIQUOR / SKENDINČIŲJŲ MEDŽIAGŲ IR AMONIO JONŲ ŠALINIMO IŠ DUMBLO VANDENS EKSPERIMENTINIAI TYRIMAI. Mokslas - Lietuvos ateitis 2014, 6, 451 -455.

AMA Style

Kasparas Gražinskas, Aušra Mažeikienė, Marina Valentukeviciene. EXPERIMENTAL RESEARCH ON REMOVING SUSPENDED SOLIDS AND AMMONIUM IONS FROM SLUDGE LIQUOR / SKENDINČIŲJŲ MEDŽIAGŲ IR AMONIO JONŲ ŠALINIMO IŠ DUMBLO VANDENS EKSPERIMENTINIAI TYRIMAI. Mokslas - Lietuvos ateitis. 2014; 6 (4):451-455.

Chicago/Turabian Style

Kasparas Gražinskas; Aušra Mažeikienė; Marina Valentukeviciene. 2014. "EXPERIMENTAL RESEARCH ON REMOVING SUSPENDED SOLIDS AND AMMONIUM IONS FROM SLUDGE LIQUOR / SKENDINČIŲJŲ MEDŽIAGŲ IR AMONIO JONŲ ŠALINIMO IŠ DUMBLO VANDENS EKSPERIMENTINIAI TYRIMAI." Mokslas - Lietuvos ateitis 6, no. 4: 451-455.

Journal article
Published: 29 April 2014 in Ekologija
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Anthropogenic activities are a major source of groundwater contamination in semi-island regions, and evaluation methods developed for inland sites may not be appropriate for coastal sites. We investigated the feasibility of diversity a nitrate-affected groundwater source-fate system in a semi-island environment using comparative methods. The study site was a groundwater well-field in Neringa, Lithuania, where nitrogen compounds obtained in groundwater had increased from the origin thereafter treatment plants. We used ammonium ions and ammonium nitrogen / organic compounds ratios and direct evaluation of total nitrogen concentration to show that biological processes occurred in both source area and water treatment, and could increase nitrogen concentrations over time. The nitrogen compounds and organic carbon compounds rate was changing water quality from the place of origin aquifer, offering a possible means of preventing diversity of the nitrogen compounds by controlling reacting rate over the site. We conclude that biological processes are the real reason of nitrogen compounds diversity at this type of site.

ACS Style

Marina Valentukevičienė; Gytautas Ignatavicius; Vaidotas Valskys. Nitrogen and organic compounds correlations in groundwater from the aquifer in a semi-island (Curonian Spit, Lithuania). Ekologija 2014, 60, 1 .

AMA Style

Marina Valentukevičienė, Gytautas Ignatavicius, Vaidotas Valskys. Nitrogen and organic compounds correlations in groundwater from the aquifer in a semi-island (Curonian Spit, Lithuania). Ekologija. 2014; 60 (1):1.

Chicago/Turabian Style

Marina Valentukevičienė; Gytautas Ignatavicius; Vaidotas Valskys. 2014. "Nitrogen and organic compounds correlations in groundwater from the aquifer in a semi-island (Curonian Spit, Lithuania)." Ekologija 60, no. 1: 1.

Conference paper
Published: 01 January 2014 in The 9th International Conference "Environmental Engineering 2014"
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ACS Style

Vaidotas Valskys; Gytautas Ignatavicius; Marina Valentukevičienė. The Analysis of Sediments Contamination with Heavy Metals after Hydro-mechanical Treatment in the Southern Part of Lake Babrukas. The 9th International Conference "Environmental Engineering 2014" 2014, 1 .

AMA Style

Vaidotas Valskys, Gytautas Ignatavicius, Marina Valentukevičienė. The Analysis of Sediments Contamination with Heavy Metals after Hydro-mechanical Treatment in the Southern Part of Lake Babrukas. The 9th International Conference "Environmental Engineering 2014". 2014; ():1.

Chicago/Turabian Style

Vaidotas Valskys; Gytautas Ignatavicius; Marina Valentukevičienė. 2014. "The Analysis of Sediments Contamination with Heavy Metals after Hydro-mechanical Treatment in the Southern Part of Lake Babrukas." The 9th International Conference "Environmental Engineering 2014" , no. : 1.

Journal article
Published: 17 June 2013 in Technological and Economic Development of Economy
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The main aim of this study was to characterize heavy metal compounds of sweep sand particles in the city of Vilnius (Lithuania). These research results provide new insight into the distribution and variation of heavy metal compounds in sweep sand in the studied area. The results of this investigation reflect the level of heavy metal pollution during the winter season, thus can be used to judge the quality of storm water flowing from streets. The major heavy metals found to have accumulated were lead, nickel, zinc and copper. These research results are useful for conducting preliminary evaluations of possible heavy metal pollution in other similar cities within the European Union. The general anthropogenic factor of three main types of land-use has the greatest influence on contamination of urban topsoil. In industrial sites, concentrations of key contaminants (Pb, Cu, Mn, Ni) are significantly higher than in residential and public–residential areas. The present article discussed the significance of systematic sustainable evaluation as one of the most important activities associated with a sustainable approach. Consequently, to reduce a negative effect of salts on street environment, measures of environmentally sustainable development have to be undertaken.

ACS Style

Agnė Kazlauskienė; Marina Valentukevičienė; Gytautas Ignatavicius. SUSTAINABILITY ASSESSMENT OF HEAVY METALS AND ROAD MAINTENANCE SALTS IN SWEEP SAND FROM ROADSIDE ENVIRONMENT. Technological and Economic Development of Economy 2013, 19, 224 -236.

AMA Style

Agnė Kazlauskienė, Marina Valentukevičienė, Gytautas Ignatavicius. SUSTAINABILITY ASSESSMENT OF HEAVY METALS AND ROAD MAINTENANCE SALTS IN SWEEP SAND FROM ROADSIDE ENVIRONMENT. Technological and Economic Development of Economy. 2013; 19 (2):224-236.

Chicago/Turabian Style

Agnė Kazlauskienė; Marina Valentukevičienė; Gytautas Ignatavicius. 2013. "SUSTAINABILITY ASSESSMENT OF HEAVY METALS AND ROAD MAINTENANCE SALTS IN SWEEP SAND FROM ROADSIDE ENVIRONMENT." Technological and Economic Development of Economy 19, no. 2: 224-236.

Journal article
Published: 11 October 2012 in Journal of Environmental Engineering and Landscape Management
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A wide range of material sources potentially contribute to contaminant loads in potable water. The ability of water supply systems to act as emission control barriers to tap water micro pollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of nitrogen micro pollutants in water supply systems. All of the investigated compounds are listed under the requirements to the quality of water intended for human consumption. Significant water quality changes are identified. A wide range of potential treatment trains are available for water treatment and reuse but treatment efficiency data for nitrogen substances is very limited. Nitrogen substances removal through water treatment is following to be predominantly due to ammonium ions, nitrate and nitrite limited concentrations requirement, with only minor contributions to the water supply network. The majority of conventional water treatment plants periodically supply water with nitrogen compounds residual to the potable water distribution system. Hence, it is important to ensure that other nitrogen sources control options (e.g. pipelines materials, and groundwater sources controls) for potable water supply continue to be pursued, in order that nitrogen compounds emissions from these sources are effectively reduced and/or phased out as required under the demands of the requirements to the quality of water intended for human consumption. The aim of this research was to estimate the correlation between nitrogen compounds, iron and manganese concentrations in drinking water supply pipelines in Vilnius (Lithuania) and Warsaw (Poland).

ACS Style

Marina Valentukevičienė; Agnieszka Karczmarczyk; Anželika Jurkienė; Auksė Grigaitytė. Research on correlation between nitrogen compounds, iron and manganese concentrations in drinking water supply systems. Journal of Environmental Engineering and Landscape Management 2012, 21, 216 -223.

AMA Style

Marina Valentukevičienė, Agnieszka Karczmarczyk, Anželika Jurkienė, Auksė Grigaitytė. Research on correlation between nitrogen compounds, iron and manganese concentrations in drinking water supply systems. Journal of Environmental Engineering and Landscape Management. 2012; 21 (3):216-223.

Chicago/Turabian Style

Marina Valentukevičienė; Agnieszka Karczmarczyk; Anželika Jurkienė; Auksė Grigaitytė. 2012. "Research on correlation between nitrogen compounds, iron and manganese concentrations in drinking water supply systems." Journal of Environmental Engineering and Landscape Management 21, no. 3: 216-223.

Journal article
Published: 01 August 2012 in Ekologija
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A wide range of material sources may potentially contribute to contaminant loads in the potable water. The ability of water supply systems to act as emission control barriers for tap water micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of manganese micropollutants in laboratory scaled water supply systems. All of the investigated compounds are listed under the European Council Directive 98/83/EC on the quality of water intended for human consumption (1998) and World Health Organization Guidelines for Drinking-water Quality (2004). Significant water quality changes are identified. Hydro-chemical modelling indicates that the removal of manganese substances during water treatment is likely to be predominant due to the EC Directive manganese concentration requirement, with only minor contributions to the water supply network. Manganese compounds are resistant to biodegradation and the majority of conventional groundwater treatment plants periodically supply water with manganese residual to the potable water distribution system. Water treatment is unlikely to act as a comprehensive barrier for emission of manganese compounds. Hence, it is important to ensure that other manganese source control options (e. g. pipeline materials, manganese substance emission, and groundwater source control) for potable water supply continue to be pursued in order that emissions of manganese compounds from these sources are effectively reduced and / or phased out as required under the demands of the European Council Directive 98/83/EC on the quality of water intended for human consumption.

ACS Style

Marina Valentukevičienė; Gytautas Ignatavicius. Presence and fate of manganese substances in drinking water supply systems. Ekologija 2012, 58, 1 .

AMA Style

Marina Valentukevičienė, Gytautas Ignatavicius. Presence and fate of manganese substances in drinking water supply systems. Ekologija. 2012; 58 (1):1.

Chicago/Turabian Style

Marina Valentukevičienė; Gytautas Ignatavicius. 2012. "Presence and fate of manganese substances in drinking water supply systems." Ekologija 58, no. 1: 1.

Journal article
Published: 01 March 2012 in Water Practice and Technology
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The aims of the work and research question deals with the removal of two natural nitrogen compounds, ammonium and nitrate and an organic compounds from groundwater in the sensitive aquatic area (Curonian Spit, Lithuania). The effects of both ammonium presence and nitrate compounds were studied using natural groundwater in the water treatment plants. Organic compounds were studied at Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), Color (Pt scale) and UV methods. The amines were varied in the range of 0.11–0.32 μg L−1. At ammonium concentration of 790 μg L−1, the amines formations were close to 0.66 μg L−1 maximum obtained in the groundwater. The highest ammonium removals were obtained at water treatment plants of approximately 15 mg L−1 TOC. Continuous tests showed a linear relationship between TOC and DOC concentration rates. The conclusions drawn that the most biodegradable compound was the ammonium. The TOC/DOC rates increased with the decreased of ammonium concentrations. Optimal process conditions in this work were obtained at the TOC and DOC of approximately 16 and 14 mg L−1, respectively, with high efficient of ammonium removal, as well as minimum amines formation rate.

ACS Style

Marina Valentukevičienė; Ramune Albrektiene. Nitrogen compounds removal by membrane filtration in water treatment plant for small communities: full-scale start-up. Water Practice and Technology 2012, 7, 1 -9.

AMA Style

Marina Valentukevičienė, Ramune Albrektiene. Nitrogen compounds removal by membrane filtration in water treatment plant for small communities: full-scale start-up. Water Practice and Technology. 2012; 7 (1):1-9.

Chicago/Turabian Style

Marina Valentukevičienė; Ramune Albrektiene. 2012. "Nitrogen compounds removal by membrane filtration in water treatment plant for small communities: full-scale start-up." Water Practice and Technology 7, no. 1: 1-9.

Journal article
Published: 18 January 2012 in Technological and Economic Development of Economy
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Drinking water distribution system takes a significant place in sustainable urban development. In order to solve some environmental issues it is necessary to improve the maintenance of the environmental impact of chemical compounds which can come in contact with water. The aim of the research is to complete the analysis of the sustainable development of drinking water pipelines in Lithuania as well as to structure the chemical content of pipelines for further increase of supplied water quality and simplification of maintenance. Analytical and descriptive methods were used in the research process. The investigation included 150 samples that were obtained in different water stagnation times in lab-scaled pipelines. During the research the following indicators were set: total iron, manganese, ammonium ions, nitrate and nitrite concentrations, turbidity and chemical oxygen demand (CODCr). To ensure sustainability of drinking water distribution system in the end of this research the appliance of a certain model of actions was considered. This model says that material of potable water network must be chosen depending on water chemical indicators, water reaction with pipeline material and scale formation causes. Consequently, to reduce a negative effect of chemical processes on the drinking water supply measures of sustainable ecological development have to be taken. Santrauka Geriamojo vandens tiekimo sistema yra labai svarbus darnios miesto plėtros objektas. Siekiant išspręsti tam tikras aplinkosaugos problemas, būtina padidinti cheminių junginių, kurie gali kontaktuoti su vandeniu, kontrolę, taip užtikrinant tinkamą poveikio aplinkai priežiūrą. Šio mokslinio tyrimo tikslas – atlikti geriamojo vandens vamzdyno Lietuvoje analizę darnaus vystymosi aspektu, struktūrizuoti cheminę vamzdynų sudėtį, siekiant pagerinti tiekiamo vandens kokybę ir supaprastinti tolesnę vandentiekio vamzdynų priežiūrą. Mokslinio darbo metu buvo taikomi analitiniai ir eksperimentiniai tyrimo metodai. Buvo ištirta 150 mėginių, paimtų iš laboratorijoje sukonstruoto vamzdyno. Mėginiai tirti atsižvelgiant į vandens išbuvimo vamzdyne trukmę. Tyrimo metu buvo nustatomi šie cheminiai indikatoriai: bendroji geležis, mangano koncentracija, amonio jonų kiekis, nitritų ir nitratų koncentracijos, drumstumas ir cheminis deguonies suvartojimas (ChDSCr). Siekiant užtikrinti geriamojo vandens tiekimo sistemos tvarumą, tyrimo pabaigoje buvo pasiūlytas tam tikras veiksmų modelis. Jis rodo, kad vandentiekio vamzdynų medžiaga turi būti parinkta pagal tiekiamo vandens cheminius indikatorius, vandens sąveikos su vamzdyno medžiaga ir nuosėdų formavimosi priežastis. Todėl būtina imtis darnaus vystymo priemonių, mažinant neigiamą cheminių procesų įtaką tiekiamo vandens kokybei.

ACS Style

Marina Valentukevičienė; Gytautas Ignatavicius; Auksė Amosenkienė. THE SUSTAINABLE DEVELOPMENT ASSESSMENT OF DRINKING WATER SUPPLY SYSTEM / GERIAMOJO VANDENS TIEKIMO SISTEMOS DARNAUS VYSTYMO VERTINIMAS. Technological and Economic Development of Economy 2012, 17, 688 -699.

AMA Style

Marina Valentukevičienė, Gytautas Ignatavicius, Auksė Amosenkienė. THE SUSTAINABLE DEVELOPMENT ASSESSMENT OF DRINKING WATER SUPPLY SYSTEM / GERIAMOJO VANDENS TIEKIMO SISTEMOS DARNAUS VYSTYMO VERTINIMAS. Technological and Economic Development of Economy. 2012; 17 (4):688-699.

Chicago/Turabian Style

Marina Valentukevičienė; Gytautas Ignatavicius; Auksė Amosenkienė. 2012. "THE SUSTAINABLE DEVELOPMENT ASSESSMENT OF DRINKING WATER SUPPLY SYSTEM / GERIAMOJO VANDENS TIEKIMO SISTEMOS DARNAUS VYSTYMO VERTINIMAS." Technological and Economic Development of Economy 17, no. 4: 688-699.

Journal article
Published: 01 January 2011 in Ekologija
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In order to reduce a negative impact of heavy traffic on the river (i. e. emission of artificial and natural particulate matter and nutrients) various scientific investigations are carried out to decide if the use of street roads is allowed or prohibited. This is particularly relevant for the towns, belonging to the transport corridors of the Lithuania‘s road networks where in some towns the circuit roads haven’t yet been developed, i. e. Marijampolė (a transit town on the road of Via Baltica). Two transport corridors of European significance, the Via Baltica highway connecting Northern Europe with Central and Western Europe and the branch of IXB transport corridor IXD Kaliningrad – Marijampolė – Kaunas, cross in Marijampolė County. Based on the scientific investigations that the use of street roads for heavy traffic causes emission of pollutants, especially those of small suspended particles and silt into the ambient water several tens of times higher than that by using the circuit roads, and generates the increase in the pollutant emission up to several tens of times, it could be stated that the use of circuit roads should be obligatory. Thus, in rainy Lithuanian autumn when the precipitation often varies around 10 mm/h, the use of street roads, when travelling of flooded and more rarely cleaned the streets of Lithuanian towns, should be only recommended if the circuit town roads are effectively developed by the new generation of road networks, i. e. less dangerous for the environment, situated from a more suitable safe distance and containing a proper runoff treatment. The dependencies used for calculating pollution loads need to be determined more accurately by test, analyzing the stormwater on the surface of roadway pavement, with further statistical estimation of the data. The experimental research performed is closely related to the study of the issues of planning and traffic pollution of various roads. Keywords: traffic emissions, particulate matter, river sediments, sieve analyses, stormwater runoff, stormwater outlets

ACS Style

Marina Valentukevičienė; Gytautas Ignatavicius. Analysis and evaluation of the effect of the solids from road surface runoff on the sediments of river bed. Ekologija 2011, 57, 1 .

AMA Style

Marina Valentukevičienė, Gytautas Ignatavicius. Analysis and evaluation of the effect of the solids from road surface runoff on the sediments of river bed. Ekologija. 2011; 57 (1):1.

Chicago/Turabian Style

Marina Valentukevičienė; Gytautas Ignatavicius. 2011. "Analysis and evaluation of the effect of the solids from road surface runoff on the sediments of river bed." Ekologija 57, no. 1: 1.

Journal article
Published: 31 October 2010 in Mokslas - Lietuvos ateitis
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In order to protect the natural environment from pollution, pollutant reduction in the stormwater runoff of urban areas is a particularly relevant factor. Uneven surface water flow and changes in pollutant concentration complicate conventional matching techniques and processes as well as prolong the duration of time which requires a comprehensive study in this area. Therefore, experiments on inflow stormwater turbidity and impurity with suspended solids and petroleum products were carried out according to the prepared sample collecting methodology. The study evaluated the effectiveness of cleaning a stormwater treatment plant along the settlement chamber in the chosen points. The settling time of impurities found in stormwater was analyzed under the presence of ideal conditions in the laboratory. The conducted experiments established dependence between suspended solids and turbidity. Stormwater pollution by SS was reduced only to 21–35% after heavy rain or a snow melting period in treatment plants.

ACS Style

Egidija Jaruševičiūtė; Aušra Mažeikienė; Marina Valentukeviciene. STUDIES AND ANALYSIS OF THE EFFECTIVENESS OF STORMWATER RUNOFF PURIFICATION EQUIPMENT IN VILNIUS. Mokslas - Lietuvos ateitis 2010, 2, 30 -35.

AMA Style

Egidija Jaruševičiūtė, Aušra Mažeikienė, Marina Valentukeviciene. STUDIES AND ANALYSIS OF THE EFFECTIVENESS OF STORMWATER RUNOFF PURIFICATION EQUIPMENT IN VILNIUS. Mokslas - Lietuvos ateitis. 2010; 2 (5):30-35.

Chicago/Turabian Style

Egidija Jaruševičiūtė; Aušra Mažeikienė; Marina Valentukeviciene. 2010. "STUDIES AND ANALYSIS OF THE EFFECTIVENESS OF STORMWATER RUNOFF PURIFICATION EQUIPMENT IN VILNIUS." Mokslas - Lietuvos ateitis 2, no. 5: 30-35.

Journal article
Published: 31 March 2010 in Journal of Environmental Engineering and Landscape Management
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Experimental investigation of ammonium ion removal from drinking water were carried out using natural zeolite (clinoptilolite) fractions of 0.3–0.6 mm and 0.6–1.5 mm. Before using natural zeolite was washed and dried in an oven at a temperature of about 105 °C. Solutions with different ion power (solution 1 ‐ supplied tap water and NH4Cl, solution 2 — distillate water and NH4Cl; initial concentration of ammonium ions of 2 mg/l) were filtrated through an experimental filter column packed with 70 mm and 210 mm of zeolite media for comparison purposes. Comparing the results for different natural zeolite fractions it was determined that the removal is more efficient using a finer fraction. After filtering 30 l of solution 1 through the laboratory‐ scaled filter column packed with 70 mm height of 0.3–0.6 mm particle size zeolite media and 0.6–1.5 mm particle size, the efficiency fluctuated from 89% to 70% (finer particles) and from 94% to 54% (coarser particles). Comparing the efficiency of ammonium ion removal from solutions with different ion power (solution 1 and solution 2), it was noticed that concentration reached the limit of 0.5 mg/l in the 12th l of solution 1, whereas it was fifty times lower in the 12th l of solution 2. After filtering 10 l of filtrate through the filter media with the height of 210 mm using coarse particles, the efficiency of ammonium ion removal reached 84%. Santrauka Eksperimentiniai NH4 + šalinimo laboratorijos salygomis iš ruošiamo geriamojo vandens tyrimai buvo atlikti naudojant gamtinio ceolito (klinoptilolito) 0,3–0,6 mm ir 0,6—1,5 mm stambumo frakcijas. Prieš naudojant gamtinis ceolitas buvo išplautas ir išdžiovintas krosnyje apie 105 °C temperatūroje. Pro eksperimentinio filtro ceolito užpildus (užpildo aukštis pirmuoju atveju buvo 70 mm, antruoju ‐ 210 mm) 5 m/h greičiu praleisti skirtingos jonines jegos tirpalai (iš vandentiekio vandens bei NH4Cl (I) ir iš distiliuoto vandens bei NH4Cl (II) pasigaminti tirpalai, kuriuose pradinD amonio jonu koncentracija buvo 2,0 mg/l). Lyginant dvieju skirtingu gamtinio ceolito frakciju eksperimento rezultatus nustatyta, kad smulkesne frakcija efektyviau iš tirpalu šalina NH4 +. Prafiltravus po 30 litru pirmojo tirpalo pro dvi 70 mm aukščio skirtingo ceolito grūdeliu stambumo frakcijas, amonio jonu šalinimo iš tirpalo efektyvumas kito atitinkamai nuo 89 % iki 70 % (esant smulkesnei frakcijai) ir nuo 94 % iki 54 % (kai frakcija stambesne). Lyginant amonio jonu šalinimo iš skirtingos jonines jegos tirpalu efektyvuma pastebeta, kad 0,5 mg/l amonio jonu koncentracija pirmojo tirpalo filtrate pasiekta jau dvyliktajame filtrato litre, o antrojo (II) tirpalo filtrato dvyliktajame litre ji buvo 50 kartu mažesne. Prafiltravus pro rege‐neruota 210 mm aukščio 0,6–1,5 mm stambumo ceolito grūdeliu užpilda 10 litru pirmojo tirpalo, amonio jonu šalinimo iš tirpalo efektyvumas sieke 84 %. Резюме Экспериментальные исследования очистки питьевой воды от ионов аммония проводились в лабораторных условиях, используя природный цеолит (клиноптилолит) с содержанием фракции 0,3–0,6 мм и 0,6–1,5 мм. Перед использованием природный цеолит был промыт и высушен в печи при температуре 105 0C. Растворы различного ионного заряда (1-й раствор из водопроводной воды и NH4Cl и 2-й раствор из дистиллированной воды и NH4Cl, в которых первичная концентрация ионов аммония была 2,0 мг/л) были пропущены через цеолитовую загрузку экспериментального фильтра со скоростью 5 м/ч (высота загрузки в первом случае составляла 70 мм, во втором – 210 мм). При сравнении результатов эксперимента с двумя различными фракциями природного цеолита обнаружено, что мелкозернистая фракция эффективнее очищает растворы от NH4+. После фильтрования 30 л первичного раствора обеими фракциями различной зернистости цеолита эффективность очистки раствора от ионов аммония достигала соответственно от 70% до 89% (мелкозернистой фракции) и от 54% до 94% (крупнозернистой фракции). При сравнении результатов удаления ионов аммония из 1-го и 2-го растворов с разными ионными зарядами в 12-м литре 1-го раствора была обнаружена концентрация ионов аммония в 0,5 мг/л, что в 50 раз меньше, чем в 12-м литре профильтрованного 2-го раствора. После того, как было профильтровано 10 л первого раствора через регенерированную цеолитовую загрузку высотой в 210 мм (фракция 0,6–1,5 мм), эффект очистки раствора от ионов аммония достигал 84 %.

ACS Style

Aušra Mažeikienė; Marina Valentukevičienė; Juozas Jankauskas. LABORATORY STUDY OF AMMONIUM ION REMOVAL BY USING ZEOLITE (CLINOPTILOLITE) TO TREAT DRINKING WATER. Journal of Environmental Engineering and Landscape Management 2010, 18, 54 -61.

AMA Style

Aušra Mažeikienė, Marina Valentukevičienė, Juozas Jankauskas. LABORATORY STUDY OF AMMONIUM ION REMOVAL BY USING ZEOLITE (CLINOPTILOLITE) TO TREAT DRINKING WATER. Journal of Environmental Engineering and Landscape Management. 2010; 18 (1):54-61.

Chicago/Turabian Style

Aušra Mažeikienė; Marina Valentukevičienė; Juozas Jankauskas. 2010. "LABORATORY STUDY OF AMMONIUM ION REMOVAL BY USING ZEOLITE (CLINOPTILOLITE) TO TREAT DRINKING WATER." Journal of Environmental Engineering and Landscape Management 18, no. 1: 54-61.

Journal article
Published: 01 January 2009 in Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
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Quality changes of drinking water in the water supply network (case study from Lithuania) The purpose of this research was to examine water quality changes by distributing in to the water supply network. Water samples were collected from Varena town (Lithuania) drinking water distribution system fed by groundwater from well field. Parameters related to undesirable increasing of nitrites and nitrates concentrations have been measured considering these samples: pH, conductivity, concentration of total iron, manganese, ammonium, nitrates and nitrites. Results showed that groundwater from well field were extremely susceptible to favor bacterial growth in the pipelines. The occurrence of nitrites and nitrates in drinking water samples correlated positively with the lengths of old iron pipelines and negatively with the content of newly laid pipelines. The obtained results also showed that the potential nitrates increasing induced by the distribution of treated water could be reduced if: nitrates levels were below detection limits at the outlet of the water treatment plant; biological ammonium removal treatment implementation should reduce the levels of the nitrates and nitrites of the treated supplied water. Although the nitrates concentration increase in drinking water distribution systems, the issues with nitrites accumulation are rare in Lithuania. However, such processes still need to be proved in more extensive investigation, but these research results could be applied as a basic scenario.

ACS Style

Marina Valentukevičienė; Auksė Amosenkienė; Regimantas Dauknys. Quality changes of drinking water in the water supply network (case study from Lithuania). Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation 2009, 41, 109 -118.

AMA Style

Marina Valentukevičienė, Auksė Amosenkienė, Regimantas Dauknys. Quality changes of drinking water in the water supply network (case study from Lithuania). Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation. 2009; 41 (2):109-118.

Chicago/Turabian Style

Marina Valentukevičienė; Auksė Amosenkienė; Regimantas Dauknys. 2009. "Quality changes of drinking water in the water supply network (case study from Lithuania)." Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation 41, no. 2: 109-118.

Monograph
Published: 22 December 2008 in Vandens ruošyklos įrenginių komplekso projektavimas
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ACS Style

A. Sakalauskas; Marina Valentukeviciene. Vandens ruošyklos įrenginių komplekso projektavimas. Vandens ruošyklos įrenginių komplekso projektavimas 2008, 1 .

AMA Style

A. Sakalauskas, Marina Valentukeviciene. Vandens ruošyklos įrenginių komplekso projektavimas. Vandens ruošyklos įrenginių komplekso projektavimas. 2008; ():1.

Chicago/Turabian Style

A. Sakalauskas; Marina Valentukeviciene. 2008. "Vandens ruošyklos įrenginių komplekso projektavimas." Vandens ruošyklos įrenginių komplekso projektavimas , no. : 1.