1. The application of zeolites for fixation of Cr(VI) ions in sedimentsMarjana Simonič, 2025, original scientific article Abstract: The aim of the study was to investigate the fixation of Cr(VI) ions from contaminated sediments using synthetic zeolite 4A and natural zeolite clinoptilolite. Parameters such as pH, contact time, adsorption mass and temperature were investigated. If the ions of the heavy metals were mobile, they would become toxic to the environment. After sediment digestion, the initial and final concentrations of Cr(VI) were measured in sediment samples with or without zeolite. Inductively coupled plasma with optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD) were used to characterize the material. The adsorption kinetics were investigated using a pseudo-first order model, a pseudo-second order model, and an intra-particle diffusion model. The results showed that the zeolites enhanced the fixation of Cr(VI). Chemisorption was the main mechanism when using acid-modified zeolite.
Keywords: sediment, fixation, heavy metals
Published in DKUM: 19.05.2025; Views: 0; Downloads: 1
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2. Adsorption of pollutants from colored wastewaters after natural wool dyeingAlenka Ojstršek, Primož Vouk, Darinka Fakin, 2022, original scientific article Abstract: The presented study assesses the efficiency of selected adsorbents, zeolite 4A in two
particle sizes and pelletized activated carbon (AC), for the potential removal of color, chemical
oxygen demand (COD), total organic carbon (TOC) and metals from wastewaters after natural wool
dyeing. Firstly, the natural coloring compounds were extracted from dried common walnut (Juglans
regia) leaves and used further for exhaustion dyeing of wool fibers, together with three different
metallic salts in two concentrations (meta-mordanting). Effluents with higher mordant concentration
were additionally treated according to a shake-flask adsorption experiment. The obtained results
revealed efficient removal of exceeded metallic ions by zeolite (up to 94.7%), on account of their
superior ion exchange capability as compared to AC. The zeolites also reduced turbidity and electrical
conductivity significantly. On the other hand, AC was more efficient for the reduction in organic
pollution, COD up to 96% and TOC up to 95%, due to its higher specific surface area and total pore
volume, and, thus, higher potential for adsorption of different compounds in comparison to 4A.
All three proposed adsorbents lowered wastewaters’ coloration remarkably, up to 78% (AC) and up
to 71% (4A), depending on the type of effluent/mordant and inspected wavelength; although, the
spectral absorbance coefficient (SAC) values remained highly above the limit values for discharge of
wastewaters into watercourses.
Keywords: wool dyeing, natural dyes, wastewater treatment, decoloration, heavy metals’ reduction, adsorption
Published in DKUM: 20.03.2025; Views: 0; Downloads: 8
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3. Enhancing utilization of municipal solid waste bottom ash by the stabilization of heavy metalsFilip Kokalj, Vesna Alivojvodić, Luka Lešnik, Nela Petronijević, Dragana Radovanović, Niko Samec, 2025, original scientific article Abstract: Waste-to-energy (WtE) is a key part of modern waste management. In the European Union, approximately 500 WtE plants process more than 100 million tons of waste yearly, while globally, more than 2700 plants handle over 500 million tons. Roughly 20% of the waste processed is bottom ash (BA). However, this ash can contain heavy metals in concentrations that may render it hazardous. This paper presents a study focusing on stabilizing municipal solid waste incineration BA using simple and industrially viable treatments. The Slovenian WtE plant operator wishes to install the stabilization process; thus, the samples obtained from the plant were treated (1) with a CO2 gas flow, (2) with water spraying, and (3) with a combination of water spraying and a CO2 gas flow under laboratory conditions. Thermodynamic calculations were applied to define potential reactions during the treatment processes in the temperature range from 0 to 100 ◦C and to define the equilibrium composition of the treated ash with additions of CO2 and water. The standard leaching test EN 12457-4 of treated ash shows a reduction of over 40% in barium concentration and over 30% in lead concentration in leachates.
Keywords: heavy metals, waste-to-energy, bottom ash, leachate, reuse
Published in DKUM: 10.03.2025; Views: 0; Downloads: 9
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4. Contaminants in the soil and typical crops of the Pannonian region of SloveniaŽiga Jelen, Milan Svetec, Peter Majerič, Stanko Kapun, Lara Resman, Tatjana Čeh, Granit Hajra, Rebeka Rudolf, 2024, original scientific article Abstract: Soil contamination and the uptake of pollutants by food crops are widespread issues that vary greatly by region and are influenced by the mineral composition of the soil and local human activities. The Pannonian region, where agriculture has played a key role since Roman times, has been particularly impacted by the long-standing agricultural and industrial practices. While soil contamination with heavy metals is monitored by the Slovenian government, microplastic contamination and the uptake of pollutants into food crops have yet to become a regular component of monitoring efforts. In this study, we conducted a preliminary investigation into soil and crop contamination across the Pannonian region, focusing on identifying harmful contaminants and their potential uptake into food crops. Both soil and crop samples were analyzed for the presence of heavy metals with proven methods such as atomic absorption spectrometry (FASS), graphite furnace atomic absorption spectrometry (GF-AAS), atomic fluorescence spectrometry (AFS), and inductively coupled plasma–mass spectrometry (ICP-MS). Energy-dispersive X-ray spectroscopy (EDS) was found to be a potentially faster method of obtaining data on soil composition. Special attention was also given to the potential presence of microplastics in the region’s soils.
Keywords: soil contamination, Pannonia, soil, food crops, heavy metals, microplastics
Published in DKUM: 28.11.2024; Views: 0; Downloads: 7
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5. Zero-Waste Approach for Heavy Metals’ Removal from Water with an Enhanced Multi-Stage Hybrid Treatment SystemDanijela Urbancl, Darko Goričanec, Marjana Simonič, 2023, original scientific article Keywords: river sediment, heavy metals, extraction process, EDTA, citric acid, natural clay
Published in DKUM: 08.05.2024; Views: 187; Downloads: 24
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7. Analysis of trace heavy metals in a sample droplet with lab-on-a-chip system : diplomsko delo univerzitetnega študijskega programa I. stopnjeNika Žurga, 2020, undergraduate thesis Abstract: The aim of this work was to develop and validate an electroanalytical method for simultaneous determination of Zn(II), Cd(II), and Pb(II) in a sample droplet with lab-on-a-chip system. Unmodified screen-printed electrodes (bare SPE using Ag/AgCl reference electrode) and Bi-film SPEs (BiFSPE) were used as electrochemical sensors. Cyclic voltammetry of [Fe(CN)6]3–/[Fe(CN)6]4– redox couple was employed for testing the reversibility of the diffusion-controlled system and square-wave anodic stripping voltammetry (SWASV) for determination of Zn(II), Cd(II), and Pb(II). SWASV was performed at deposition potential of –1.5 V vs. Ag/AgCl and deposition time of 60 s. The following validation parameters were examined: limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy, and precision.
LOD and LOQ for Zn(II) were both lower with BiFSPE than with bare SPE. For Cd(II), LOD and LOQ were similar for both bare SPE and BiFSPE. For Pb(II), LOD and LOQ with bare SPE could not be determined (due to intense background contribution) but were obtained with BiFSPE. Linear concentration ranges were obtained for all analytes with bare SPE and BiFSPE. Accuracy and precision were evaluated for different spiked concentrations; however, the method with bare SPE was neither accurate nor precise. With BiFSPE, the method was found to be both accurate and precise for Pb(II) at a spiked concentration of 140.0 μg/L, but not for Zn(II) or Cd(II). For the latter, problems with accuracy and precision were encountered with both bare SPE and BiFSPE. Both methods were selective for Zn(II), Cd(II), and Pb(II) determination. It can be concluded that the optimization of both methods is required for future studies.
Keywords: SPE, BiFSPE, heavy metals determination, SWASV, validation
Published in DKUM: 31.08.2020; Views: 1211; Downloads: 192
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8. Sensing heavy metals using mesoporous-based optical chemical sensorsŠpela Korent Urek, Nina Frančič, Matejka Turel, Aleksandra Lobnik, 2013, review article Abstract: Heavymetal pollution is one of the more serious environmental problems; therefore, there is a constant demand for the development of new analytical tools for its monitoring. An optical chemical sensor represents a good alternative to classical instrumental methods.The mesoporous materials used in optical chemical sensorsʼ fabrications have properties such as high porosity, exceptional adsorption capacity, tuneable 3D shape, geometry, and morphology, which enable improved limit of detection, response time, and selectivity properties of optical sensors. In this review, we firstly present the properties of mesoporous materials, provide a brief description of sensing mechanisms, and briefly discuss the importance of continuous monitoring. Recent advances in those mesoporous silica-based optical sensors used for heavy metal detection have been reported and their advantages and limitations also discussed. This review covers publications that have appeared since 2008.
Keywords: heavy metals, magnetic properties, structural properties, heavy metal pollution
Published in DKUM: 14.06.2017; Views: 3227; Downloads: 358
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