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Advances in monitoring and understanding the dynamics of suspended-sediment transport in the river Drava, Slovenia: an analysis more than a decade-long
Janja Kramer Stajnko, Renata Jecl, Matjaž P. Nekrep, 2023, original scientific article

Abstract: Managing sediment transport in streams is crucial to the surface water resource development strategy and has several implications for flood risk and water management, hydropower use, and balancing river morphology. This paper summarises the movement and behaviour of suspended sediment within the Slovenian portion of the River Drava, covering a span of thirteen years from 2005 to 2018. An analysis of relevant data collected during this period is also presented. Suspended-sediment dynamics strongly depend on flow velocity, seasonal variations in sediment sources, and human interventions in the riverbed. The transportation of material in the River Drava results in the accumulation of sediments in reservoirs and riverbeds, consequently impeding the natural hydrological cycle by reducing the outflow into aquifers. The 2018 high-water event is analysed in terms of the dependence of concentration of suspended sediments on discharge, where counterclockwise hysteresis was observed, providing an essential clue to the origin of sediment. Sediments from the River Drava in Slovenia are managed with some conventional processes and are mainly deposited or reintegrated into rivers and aquatic ecosystems. Some additional sediment management strategies with long-term solutions for efficient and comprehensive water management, hydropower, and ecological problems are proposed.
Keywords: sediment transport, streams, suspended sediment dynamics, suspended sediment transport, river Drava, sediment management, monitoring, water management
Published in DKUM: 13.09.2023; Views: 476; Downloads: 43
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3.
Možnosti uporabe zeolitov za fiksiranje kovinskih ionov v sedimentih : diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje
Sara Grm, 2023, undergraduate thesis

Abstract: Namen diplomske naloge je bila študija možnosti uporabe zeolitov za fiksiranje Cr(VI), Zn(II) in Pb(II) ionov v kontaminiranih sedimentih. Za fiksacijo navedenih kovinskih ionov smo uporabili mešanico sintetičnih zeolitov 13X in 4A, v razmerju 1:1. Sedimente za študijo fiksacije Cr(VI) ionov smo vzorčili v bližini Zreč, za Zn(II) in Pb(II) ione pa smo sedimenti vzorčili iz reke Drave. V določeno maso sedimentov smo v razmerju 100:1 in 10:1 dodali zeolite. Vzorčenim sedimentom smo pred začetkom izvajanja meritev tudi določili vlažnost s postopkom žarjenja in smo se odločili, da bomo v njih tudi opazovali fiksacijo Cr(VI) ionov. Tako pripravljene vzorce smo hranili v temnem prostoru, da smo se čim bolj približali pogojem, v katerih se sediment nahaja v naravi. Preučevali smo uspešnost fiksacije pri različnih temperaturah in pH vrednostih. Vsebnost kovinskih ionov smo merili v času 3 mesecev. Celotno vsebnost kovinskih ionov v vzorčenih sedimentih smo določili z EDTA. Po zaključenem eksperimentu smo ugotovili, da je zeolit učinkovito sredstvo za fiksiranje Cr(VI), Zn(II) in Pb(II) ionov v sedimentih. Fiksacija Cr(VI) ionov je bila najboljša pri vzorcu hranjenem pri sobni temperaturi in nevtralnem pH z uporabo razmerja 10:1 dodanih zeolitov. Fiksacija Zn(II) ionov je bila najboljša pri sedimentih hranjenih pri 4 °C pri bazičnem pH, z uporabo razmerja 100:1 dodanih zeolitov. Fiksacija Pb(II) ionov je pri vseh preučevanih vzorcih bila enaka, saj smo vsem vzorcem izmerili vsebnost Pb(II) ionov pod mejno vrednostjo.
Keywords: zeolit, fiksacija, težke kovine, sediment
Published in DKUM: 11.09.2023; Views: 368; Downloads: 71
.pdf Full text (2,59 MB)

4.
Možnost ponovne uporabe sedimenta po čiščenju odpadnih voda iz mlečno predelovalne industrije : magistrsko delo
Laura Jug, 2020, master's thesis

Abstract: Velika količina sedimenta, ki nastane pri čiščenju odpadnih voda iz mlečno predelovalne industrije, skupaj z okoljskimi vplivi in strogimi zakonskimi predpisi predstavlja problematičen segment in postavlja vprašanje glede njegovega trajnostnega upravljanja. V magistrski nalogi smo z namenom raziskanja ponovne uporabe sedimenta po čiščenju odpadnih voda iz mlečno predelovalne industrije preučili primernost štirih organskih polielektrolitov kot alternativnih reagentov klasičnim anorganskim koagulacijskim sredstvom. Z izvedbo JAR testa in uporabo nizko molekularnega hitozana, natrijeve karboksimetil celuloze, polietilenimina in kolagena smo preverili učinkovitost čiščenja odpadnih voda iz mlečno predelovalne industrije ter pri tem analizirali karakteristike nastalega sedimenta. Rezultati so pokazali, da z izbrano metodo in uporabljenimi koaglacijsko/flokulacijskimi sredstvi pri preiskovanih pogojih nismo uspeli zadostno odstraniti v vodi prisotne nečistoče in s tem prečistiti vode tako, da bi ustrezala zakonsko določenim mejnim parametrom. Z vidika nastalega sedimenta smo najboljše rezultate obarjanja dosegli z uporabo nizko molekularnega hitozana in s spreminjanjem vrednosti pH po končanem JAR testu. Na podlagi dobljenih rezultatov IR spektroskopije smo v nastalem sedimentu zaznali signale, ki nakazujejo na prisotnost organskih kislin in vezi ogljikovodikov oborjenih iz odpadne vode. Končna analiza sestave mikrobne združbe je pokazala, da v pridobljenem sedimentu primarno ni prisotnih patogenih mikroorganizmov oziroma bakterij.
Keywords: sediment, odpadna voda, mlečno predelovalna industrija, polielektroliti, krožno gospodarstvo
Published in DKUM: 30.06.2020; Views: 1117; Downloads: 117
.pdf Full text (1,47 MB)

5.
Analysis of concentration and sedimentation of suspended load in the reservoirs
Helena Vrecl-Kojc, Bojana Dolinar, Roman Klasinc, Ludvik Trauner, 2008, original scientific article

Abstract: This paper deals with the sedimentation of suspended load in the reservoirs. As an example the reservoir of the hydroelectric power plant Boštanj on the Sava River is shown. The objective of the described studies was to determine the quantity and type of deposited material in the reservoir during the selected time period. For this purpose, the mineral and chemical composition, and the concentration and the particle size of the suspended load at the intake of the water into the reservoir and at its outflow were examined. In order to determine the concentration of the suspended load, 24 water samples from the area of the intake and outflow from the reservoir were taken. At the same time the discharge of the Sava River was measured. Solid particles were removed from the water with the help of sedimentation and in the final stage of water evaporation. The results of the studies showed that the concentration of the suspended material was changing in relation to the location and the flow rate of the water. This ratio can be described with an exponential function. In suspended load composition carbonates, muscovite/illite and quartz dominate; however, chlorite was also found, as well as small quantities of plagioclase and organic detritus. With regard to the size of the particles the examined samples are classified as silt. It was determined that the concentration of the suspended load, at the same flow rate of water, at the intake into the reservoir is larger than at the outflow. The difference is represented by the material that was sedimented in the reservoir due to the decreased speed of the water as a result of the river's impoundment. A comparison of the composition of the samples from both collection sites showed that at the outflow site of the water from the reservoir there is a somewhat smaller share of carbonate grains and heavy minerals than at the intake site, and a higher content of organic detritus and clay particles can also be observed. Considering the actual discharge of water in the period between July 2006 and July 2007 and the examined ratio between the flow rate of the water and the quantity of suspended and deposited material, the total quantity of sedimented material in this period was estimated.
Keywords: suspended load, sedimentation, sediment transport, water storage reservoir
Published in DKUM: 05.06.2018; Views: 2091; Downloads: 83
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6.
An evaluation of marine sediments in terms of their usability in the brick industry : case study Port of Koper
Patrik Baksa, Franka Cepak, Rebeka Kovačič Lukman, Vilma Ducman, 2018, original scientific article

Abstract: A dredging process is essential for the development of harbours and ports, allowing the functional daily operation of the port. The management of dredged material represents a worldwide challenge, especially considering unwanted deposition of material. Because of their chemical, petrographic, mineralogical and homogeneity composition, marine sediments could represent an appropriate raw material for the brick industry, particularly for the production of clay blocks, roofing and ceramic tiles. In this study dredged material from Port of Koper was tested for such use, thus various analyses were carried out in order to determine if the dredged material is environmentally friendly and suitable for use in the brick industry. These included: chemical analysis, mineralogical analysis, particle size analysis, chloride content analysis and tests of firing in a gradient furnace. Furthermore, tests of mechanical properties, as well as tests of the frost-resistance of the samples were carried out. On the basis of the primary analyses and samples prepared in a laboratory, it was confirmed that marine sediments from the Port of Koper, without any additives are only conditionally suitable as a source material for producing brick products, because without additives they exhibit too much shrinkage on drying and firing, as well as high water absorption, this can be improved by the incorporation of suitable additives, for example, virgin clay or other suitable waste material. The approach described herewith can also be followed to assess sediments from other ports and rivers regarding its potential use in clay brick sector.
Keywords: dredge marine sediment, recycling, clay bricks, mechanical properties, chemical analysis
Published in DKUM: 21.12.2017; Views: 2628; Downloads: 201
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7.
Analiza vsebnosti in transporta suspendiranih sedimentov na izbranem mestu v reki Dravi
Marko Vinkovič, 2016, diploma project paper

Abstract: V diplomski nalogi smo predstavili probleme, ki jih povzročajo suspendirani sedimenti v rekah z okoljevarstvenega in inženirskega stališča. Predstavljeni so nekateri načini izvajanja meritev. Posebej smo opisali metodo merjenja z akustičnim Dopplerjevim merilnikom pretokov s katero so se opravljale meritve na Fakulteti za Gradbeništvo prometno inženirstvo in arhitekturo. Podatke meritev, ki so se opravljale na izbranih mestih na reki Dravi smo uporabili za namene analize, kar predstavlja osnovo za nadaljnjo modeliranje vsebnosti in dinamike suspendiranih sedimentov
Keywords: suspendirani, sediment, transport, analiza, meritve
Published in DKUM: 21.09.2016; Views: 1542; Downloads: 135
.pdf Full text (1,56 MB)

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