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1.
Water pollution in the impact areas of the two abandoned metal ore mines in Slovenia and Portugal
Doroteja Gošar, 2015, diplomsko delo

Opis: Mining in both Mežica zinc and lead mine and in Freixeda gold mine caused negative environmental impacts. The main objective of the thesis was to study negative impacts on water quality through time. During the process various literature sources were studied, field work and chemical analyses were performed and interpretation of results with different statistical methods was done. In Mežica mine the quality of surface water has improved through time and nowadays the Meža River is of good quality. The biggest change was shown in the case of Helena rivulet, where Pb, Zn and Cd concentration between 2002 and 2015 lowered below limit values. Preventive measures and treatment of waste deposits had positive impact on water quality and based on standards for drinking water, groundwater from mine could be a source of drinking water. In Freixeda stream concentration of heavy metals lowered through time and in 2015 values of Zn, Pb, Cd and Cu in Freixeda stream before confluence with the Tua River were below the limit value. An exception is the increased value of As, which was caused by acid mine drainage (AMD) inflow from the mine, but also by the discharge from confined aquifer to Freixeda stream. Treatment of AMD was efficient for a while but due to lack of maintenance it is no longer effective.
Najdeno v: ključnih besedah
Ključne besede: Abandoned mines, heavy metals, pollution, Mežica mine, Freixeda mine
Objavljeno: 05.10.2015; Ogledov: 2492; Prenosov: 155
.pdf Polno besedilo (4,82 MB)

2.
On the limits of acoustic emission detectability for twinning
A Vinogradov, E Vasilev, M Seleznev, K Máthis, D Orlov, D Merson, 2016, izvirni znanstveni članek

Najdeno v: ključnih besedah
Ključne besede: Metals and alloys, Deformation and fracture, Grain boundaries, Twinning, Acoustic emission
Objavljeno: 20.02.2017; Ogledov: 1380; Prenosov: 0
.pdf Polno besedilo (450,28 KB)

3.
Heavy metal analysis with in-situ prepared copper film electrode as a tool for environmental monitoring
Nana Ivana Hrastnik, 2017, magistrsko delo

Opis: Monitoring and measuring heavy metals in the environment is of great importance and requires sensitive and reliable analytical techniques capable of detecting trace level concentrations. Nowadays, measurements of heavy metals are usually performed using sophisticated and expensive instrumental techniques, such as atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES) etc. In this aspect, advanced electroanalytical (stripping) techniques represent a favourable alternative, facilitating sensitive and selective measurements of various analytes using relatively simple, portable and non-expensive instrumentation. This work is an investigation of novel copper-based electrodes for measuring trace levels of selected heavy metal ions, i.e. mercury(II), lead(II), tin(IV) and nickel(II). The methods of choice were anodic stripping voltammetry (ASV) in combination with the in-situ prepared copper film electrode (CuFE) for measuring low concentrations of mercury(II) and lead(II) (simultaneously) and tin(IV) in the test solutions and adsorptive cathodic stripping voltammetry (AdCSV) for determination of nickel(II). Metal-film electrodes are regularly employed in electrochemical stripping analysis due to their simple fabrication and surface regeneration. The newly developed CuFE appears to be a cheaper alternative to gold-based electrodes with several attractive electroanalytical characteristics, i.e. with low limits of detection (LOD), good repeatability and favourable linear response.
Najdeno v: ključnih besedah
Ključne besede: Copper film electrode, anodic stripping voltammetry, adsorptive cathodic stripping voltammetry, heavy metals, environment.
Objavljeno: 12.09.2017; Ogledov: 1461; Prenosov: 106
.pdf Polno besedilo (1,78 MB)

4.
Alternative Recovery and Valorization of Metals from Exhausted Catalytic Converters in a New Smart Polymetallic Catalyst
Oreste Piccolo, Laura Sperni, Michele Gallo, Katarina Vogel-Mikuš, Iztok Arčon, Franco Baldi, Sebastiano Tieuli, Stefano Paganelli, 2019, izvirni znanstveni članek

Opis: A new metals-polymeric composite, Metx-EPS (I), was prepared to be used as catalyst in water or in two-phase aqueous conditions. The metals source was an exhausted catalytic converter that was grinded and treated with an acidic solution at room temperature. After filtration, the solution was concentrated, neutralized and added to a broth of Klebsiella oxytoca DSM 29614 to produce (I) where metals are embedded in a peculiar polysaccharide structure (EPS). The composite was easily recovered from the fermentation broth and purified. The process protocol was verified many times and was shown to be reproducible satisfactorily. The % recovery of metals, originally present in the converter, was good as determined by atomic absorption. The morphology and the chemical state of main metals in (I) were investigated by X-ray absorption spectroscopy methods (XANES and EXAFS). No metallic alloy seems to be evident. The catalytic activity and a possible synergic effect due to the presence of the different metals was valuated in the hydrogenation of some substrates, valuable precursors for theproduction of fine chemicals.
Najdeno v: ključnih besedah
Ključne besede: Biogenerated polymetallic exopolysaccharide, biphasic catalysis, hydrogenation, metals-polymeric composite, new catalyst from metallic wastes, EXAFS, XANES
Objavljeno: 06.05.2019; Ogledov: 192; Prenosov: 0
.pdf Polno besedilo (2,87 MB)

5.
A Biogenerated Polymetallic Catalyst from Society's Wastes
Oreste Piccolo, Stefano Paganelli, Petro Zanatta, Sebastiano Tieuli, Laura Sperni, Franco Baldi, Iztok Arčon, Michele Gallo, Katarina Vogel-Mikuš, 2019, izvirni znanstveni članek

Opis: Aims:Preparation of the new metals - polymeric composite, Met x-EPS (I), to be used as a green catalyst in water or in two-phase aqueous conditions. Study Design: Recovery and valorization of polymetallic wastes to obtain directly new catalysts using a microorganism to explore their application in removal of difficult and dangerous chemical pollutants present in aqueous environment
Najdeno v: ključnih besedah
Ključne besede: Metals - polymeric composite, biogenerated polymetallic exopolysaccharide, new catalyst from metallic wastes, hydrodechlorination of PCBs in water
Objavljeno: 06.05.2019; Ogledov: 259; Prenosov: 0
.pdf Polno besedilo (373,55 KB)

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