Search Results (31)

This study evaluates the potential health risks posed by geogenic arsenic in environments suitable for leisure activities, such as walking, bathing, and playing, for adults and children alike, as well as in neighbouring agricultural areas. The study includes an analysis of environmental characteristics and the main stream originating in the adjacent mining area, with water and sediment samples taken. The study area is representative of other areas in the vicinity of the Mar Menor Lagoon, which is one of the largest and most biodiverse coastal lagoons in the Mediterranean Sea. The general characteristics of the soil and water were determined for this study, as was the concentration of As in the soil and water samples. A granulometric separation was carried out into four different fractions (<2 mm, <250 µm, <100 µm, and <65 µm). The mineralogical composition, total As content, and bioaccessible As content are analysed in each of these fractions. This provides data with which to calculate the danger of arsenic (As) to human health by ingestion and to contribute to As bioaccessibility studies and the role played by the mineralogical composition and particle size of soil ingestion. The conclusions rule out residential use of this environment, although they allow for eventual tourist use and traditional agricultural use of the surrounding soils. Full article

This article presents the X-ray fluorescence and X-ray diffraction analysis results and the granulometric composition of silicon production cyclone dust and its flotation enrichment products. The technology used for the preliminary preparation of cyclone dust before flotation enrichment is presented. The process of fine media flotation should include the careful preparation and reliminary processing of raw materials, otherwise it is difficult to achieve high flotation selectivity. Technological preparation necessarily includes the following stages: preliminary preparation of dust for flotation; repulping of prepared dust; sonochemical treatment of pulp; gravitational separation of sand phase; flotation separation. A structural diagram of the flotation separation technology used for the silicate and carbon phases of cyclone dust has been developed. As a result of this research, the characteristics of cyclone dust have been obtained, allowing us to draw conclusions about the possibility of its flotation processing and further use of the obtained products in the construction industry. The results of a study of carbon in a froth product have also been obtained. Carbon nanotubes have been discovered. Full article

Recent increases in the demand for automotive lithium-ion batteries (LIBs) have led to higher needs for critical materials like lithium, cobalt, nickel, and graphite. Consequently, recovering materials from spent batteries has gained importance. This study aimed to (1) develop a mechanical pretreatment method for separating and concentrating materials from spent NCM₈₁₁ cells and (2) evaluate the economic, environmental, and shortage potentials of these fractions. The pretreatment involved grinding and granulometric separation, producing six particle-size fractions. The main novelty of the study was the assessment to identify the particle size fractions which are priorities for recycling for decision-making by recycling companies, optimizing their resources and efforts. Analysis showed that the finest fraction (n < 0.5 mm) had 85% of lithium, 77.4% of cobalt, 75.1% of manganese, and 68.5% of nickel. This fraction represented 40.4% of the processed mass and had the highest economic value (USD 3669/ton NCM cell). This fraction was also prioritized for recycling due to its superior environmental impact (103,788 kg CO₂-eq/ton NCM cell) and scarcity considerations. Furthermore, the black mass of NCM was the priority for recycling and had greater economic, environmental, and supply risk potential than the black mass of LFP cells. Full article

In this investigation, the Taguchi method was employed to optimize a mix based on four natural by-products for rammed earth construction. Two separate studies were conducted to enhance the dry density and the Unconfined Compressive Strength (UCS). The four materials were assessed across four different levels, with moisture content also factored in as a parameter within a statistical analysis of 16 combinations. The Taguchi method predicted the combinations in which the Particle Size Distribution optimized the dry density and UCS as well as their dry density and UCS values. From the results, Moisture Content was the parameter with the highest influence on the optimization as well as the dry density and the UCS. It was observed that there was a direct relationship between the bulk density of the different granulometric fractions and their influence on the mix’s dry density. The fines were the material constituents that showed the highest influence on the mix UCS. When using the Taguchi method in RE building, the factor that should be maximized should is the mechanical strength. Full article

Modeling water flow and contaminant transport in the unsaturated zone is a difficult task that relies heavily on good hydrodynamic soil characterization. This article presents a complementarity between experimentation, direct modeling and inverse modeling in order to provide a better estimate of the hydrodynamic parameters of stratified alluvial soil in the El Haouareb region of the Kairouane plain in Tunisia. A field sampling campaign was carried out. The samples collected underwent particle size analysis, bulk density measurements and infiltration tests using a mini-Muntz. In parallel, simple evaporation tests were applied to separate strata. In addition, a 2 m soil column was reconstituted and fitted with sensors to monitor water content, tension, temperature and electrical conductivity. An internal drainage test was performed on this monolith. Three methods were applied using experimental data to estimate soil hydrodynamic parameters. In the first method, pedotransfer functions were used (Rosetta platform) based on granulometric results and bulk density. In the second, water tension and water content monitored during the simple evaporation test were used to plot the soil–water retention curve (SWRC) using SWRC-Fit. In the third method, inverse modeling was applied to the internal drainage test. A comparison of the results showed that the inverse method had the lowest RMSE. Uncertainty analysis has been implemented for both the experimental and numerical set up. Full article

This study evaluated the effects of solely and integrated application of inorganic (NPK), commercial organic (NC), and biological (MIX, mixed strains Ensifer meliloti and Azotobacter chroococcum) fertilizers on the chemical characteristics of arugula biomass and its yield, as well as changes in soil microbiological parameters after the experiment in relation to the control treatment (Ø). The experiment was performed in semi-controlled greenhouse conditions, in pots, from the 4th decade of March to the 2nd decade of September, in 2023, at three cutting times/swaths, during one agricultural season, with Vertisol soil. For soil characterization, the following parameters were analysed: granulometric composition using sieving and sedimentation procedure; soil acidity—potentiometrically; SOM—soil organic matter by Kotzmann method; total N using CNS analyser; available P—spectrophotometrically; available K—flame photometrically; total number of microorganisms on an agarized soil extract medium; fungi on a solid Czapek agar; actinomycetes on a solid Krasiljnikov agar with saccharose; Azotobacter spp. on a liquid Fyodorov medium with mannitol; ammonifiers on a liquid medium with asparagine; and dehydrogenase activity—spectrophotometrically. For plant characterization, the following parameters were determined: N and C, both on CNS analyser; P on spectrophotometer; K on flame photometer; air-dried yield biomass. A stimulative effect on all microbiological parameters was found in the treatment with integrated use of organic and biological fertilizer, except for fungi, which grew better in the treatments with separate inorganic and organic fertilizers. Generally, the stimulative impact on plant chemical parameters manifested in combined inorganic and biological, organic and biological, and inorganic and organic fertilization treatments, and was inhibited in treatment without fertilization, in all three swaths, which could also be stated for the plant yield. Positive influence of all fertilization treatments on chemical parameters was observed for the second swath in relation to the first and the third. The total yield in the NPK+MIX treatment was 121%, and in the NC+MIX treatment, it was 87% higher compared to the control (Ø). In general, integrated use of inorganic and biological, organic and biological, and inorganic and organic fertilizers, respectively, could be proposed as an optimal fertilization treatment in arugula cultivation. Full article

The possibility of using waste tailings produced by flotation in the lead and zinc mine of Grot, Serbia as a potential source of secondary mineral raw materials was examined. The aim of the research was primarily to carry out a detailed characterization in order to determine the dominant minerals, and, for the first time, to trace the changes occurring in the unit cells of the minerals present in that deposit. There was also a need to determine the exact proportions of the present mineral phases for their further application and utilization as natural resources in environmental protection. Samples were taken from three different sections of tailings: the crest of dam (JKB), outlet pipe of the flotation facility (JOF) and hydrocyclone overflow (JHC). Granulometric separation was performed to facilitate the extraction of certain minerals from waste. The results showed that all samples mainly contained quartz, clinochlore, calcite, albite, pyrite and biotite, but their ratios in each sample varied significantly. After characterization, samples were separated into different fractions and their mineralogical compositions were determined. Depending on the fraction, the mineralogical compositions also changed. Mineralogy and geochemical analysis indicate that waste tailings can be used as a secondary mineral raw materials source applicable in various industries. Full article

In this paper, the properties, mineral magnetic modification, and beneficiation of tailings from the central mining and processing plant in Kryvyi Rih, Ukraine, have been studied. Samples were investigated by X-ray diffraction, X-ray fluorescence, microscopy, and magnetization measurements. The beneficiation was conducted using magnetizing roasting with carbon monoxide followed by dry low-intensity magnetic separation. The effects of chemical, mineral, and granulometric composition on the processing of fine tailings of different sizes sampled at different points of the tailings pond were investigated. Additionally, we proposed a new approach for magnetic separation of fine magnetically modified tailings based on the combination of permanent and alternating magnetic fields. Magnetizing roasting resulted in an enhancement in mass magnetization to 11–62 Am²/kg in comparison with initial values of 0.3–1.5 Am²/kg. After magnetic separation, the magnetic concentrates consisted almost completely of magnetite (with the magnetization of 75–88 Am²/kg) and non-magnetic residues contained major quartz. The content of iron in magnetic concentrates reached 68.5–70.2 wt.% and iron recovery 77–96 wt.%, depending on size fraction. We could conclude that the tailings are represented by fine-grained liberated material that can be effectively upgraded using magnetizing roasting and magnetic separation into two valuable products, such as iron concentrate and quartz powder. Full article

Granulometric aggregate fractions (20 µm–2 mm) of chernozem soils with different agriculture-use histories (native steppe, permanent bare fallow, arable land, and shelterbelt) were investigated in mid-IR and far IR regions (4000–100 cm⁻¹) by heating in the air from 25 to 215 °C, using ATR FTIR and linear discriminant analysis to differentiate the land-use samples without chemical perturbation. The temperature dependences of the band maxima significantly differed for bands of silicate matrix and bands with the contribution of soil organic matter and were more stable to experimental conditions compared to the absolute positions. The thermal behavior of the integral intensities of the IR bands at 790–750 cm⁻¹ and 440–420 cm⁻¹ that was different compared to pure quartz, may be attributed to –C–H bending of alkanes and (poly)aromatic structures and skeletal bending, and could be used to distinguish intact soils from agriculturally used samples. The different temperature behaviors of the bands for fractions of soils with different land use are shown, with the maximum difference in fractions below 20–50 µm and medium fractions (50–200 µm). Changes in the band-maximum frequencies and the integral intensities of the bands were reversible for a heating–cooling cycle. The linear discriminant analysis of the spectra obtained for granulometric fractions of chernozem soils made it possible to separate the samples of native steppe, arable land, bare fallow, and shelterbelt with a high probability based on the type of vegetation and agrogenic load, mainly on the basis of the spectral ranges associated with biogenic forms of quartz and phytoliths. Full article

The paper presents the research study on the concentration of Fe, Mn, Cu, Pb, Zn, Cd and Ca in the sediment as well as in the supernatant (layer of water just above the sediment) of the Bagry Lake, Cracow (Poland); Ca was not included in the supernatant analysis. There are a number of works in the literature on the concentrations of metals in the water environment of flow-through dam reservoirs and factors influencing their distribution. These reservoirs were created for various purposes, e.g., water supply, flood protection, leveling the flows in the rivers and recreational purposes. Since it is difficult to find information on metals and factors influencing their distribution in the aquatic environment of post-exploitation reservoirs, this work aims to fill this gap. The additional purpose of the work was to assess the potential influence of metals’ presence in the sediment of Bagry Lake on benthic organisms. Correlations between metals in the sediment and their volatile and mineral fractions as well as in particle size fractions of ≥0.06 mm and <0.06 mm were determined. Except for cadmium, metals showed a positive correlation with the sediment volatile fraction of granulometry <0.06 mm (a clay-silty fraction). It has been shown that metals, in both supernatant and sediment, are of an anthropogenic origin related to previous on-lake operations, as well as a nearby modern technical infrastructure. Statistical models were used to measure the strength of relationships between the concentration of various metals in the sediments. A cluster analysis was used to study interactions between the concentration of metals in supernatant, in sediment and in its volatile and mineral fractions as well as in fractions with different granulation. It was found that individual metals and sediment fractions form pairs of quite strong clusters, e.g., Fe sediments and Mn sediments, Fe supernatant and Mn supernatant, Cu supernatant and Pb supernatant, volatile fraction and mass fraction of particles < 0.06 mm and mineral fraction and mass fraction of particles ≥ 0.06 mm. The equilibrium model “supernatant—sediment mineral fraction—sediment volatile fraction” was developed for metals in various granulometric fractions of the sediment as well as in the supernatant. The model estimated a metal concentration in both fractions of the sediment (separately) as well as an impact they had on the metal concentration in the supernatant. It also showed how changes in a metal’s concentration in both fractions are reflected in concentrations of metals in the aquatic environment. Full article

In the literature, mainly particle-size distribution (PSD) analyses in the soil catenas, of e.g., moraine and riverine landscapes were discussed. Analysis and comparison of PSD in moraine (ML) and ice-dammed lakes (ID-LL) landscapes were not studied. Since the landscape of ice-dammed lakes origin has diversified relief and is under intensive agricultural use, the aspects of erosion are of great importance. The changes in PSD were studied in 14 soil catenas (toposequences) of eroding soils at the upper slope (US) as well as colluvial soils at the middle (MS) and lower (LS) slopes and in the depressions (D). The PSD of the fine fractions (<2 mm) was analysed according to the hydrometer method. In order to describe the effect of agricultural use on the variability of PSD in soil surface horizons, sedimentological and granulometric indices were calculated. In the studied moraine landscape, the content of coarse silt fraction was increasing in the catenal sequence from 9.7% in the US to 17.7% in the D. Similar relationships were revealed for the fine silt content. Significant differences were found between the average contents of coarse and fine silt fractions at the US as well as the LS and the D. However, such a relation was not found in the soil catena in the ice-dammed lake landscape. Eroded and colluvial soil materials were very poorly sorted with a standard deviation index of 2.65–3.69. Humus horizons of analysed soils had very fine, fine skewed PSD, mesokurtic and platykurtic distribution (ML), symmetrical, fine skewed and platykurtic distribution (I-DLL). The cluster analysis enabled the separation of two groups of soils: one group in the moraine landscape and the other in the ice-dammed lakes landscape. The PSD in studied soils was similar only among the soils within one type of landscape. Full article

The Aviles Canyon System (Northern Atlantic coast of Spain) is one of the ten marine regions studied in the Spanish seas by the LIFE+ INDEMARES project, which aims to identify special areas of conservation within the Natura 2000 Network. This study aims to characterize the composition and distribution of the macrobenthic fauna in order to provide baseline data to obtain a basic knowledge of the environment. Three oceanographic surveys were carried out to investigate species and habitats of this deep-sea ecosystem. The stations were sampled using a box corer, in order to evaluate the distribution and biodiversity of the macroinfauna, and to analyse the granulometric composition and the organic matter content. Sediments were mainly sandy in nature, the finest sediments with the highest organic matter content were found in the deepest areas, while coarser sediments were located in shallow stations. Polychaetes were the best represented group in total number of species and individuals, followed by crustaceans and molluscs. Five major macrobenthic assemblages were determined through multivariate analyses. Bathymetry and sedimentary composition were the main factors structuring the benthic community separating shallow and coarser stations from deeper and finer ones. Full article

This paper presents a study on the effectiveness of texture analysis of remote sensing imagery depending on the type and spatial resolution of the source image. The study used the following image types: near-infrared band, red band, first principal component, second principal component and normalized difference vegetation index images of pixel size from 2 m to 30 m, generated from a multispectral WorldView-2 image. The study evaluated the separability of the selected pairs of the following land cover classes: bare soil, low vegetation, coniferous forest, deciduous forest, water reservoirs, built-up areas. The tool used for texture analysis was granulometric analysis based on morphological operations—one of less popular methods which, however, as demonstrated by previous studies, shows high effectiveness in separating classes of different texture. The conducted study enabled researchers to evaluate the significance of image type and resolution for visibility of texture in the image and the possibility of using texture to differentiate between classes. The obtained results showed that there is no single, universal combination of conditions of texture analysis, which would be the best from the point of view of all classes. For most of the analyzed pairs of classes, the best results were obtained for the highest spatial resolution of the image (2–3 m), but the class of built-up areas stands out in this comparison—the best distinction was obtained with the average spatial resolution (10–15 m). Research has also shown that there is no single type of image that is universally the best basis for texture analysis. While for the majority of classes the image of the first principal component was the best, for the class of built-up areas it was the image of the red channel. Full article

Iron titaniferous sands, also called black sands, are a source of various magnetic minerals, such as iron and titanium (Fe–Ti) oxides, with countless scientific and industrial applications. Ecuador is deemed a geo-diverse country that contains deposits of black sands in the Andean and coastal regions; therefore, the industrialization of these magnetic sands might be of high interest. This study presents a preliminary industrial design for the magnetic separation process of Fe–Ti oxides from iron titaniferous Ecuadorian beach sands. Four stages are considered for the process, involving collecting, drying, screening, and magnetic separation. This proposal returns the large particles (>150 μm) and the non-magnetic fraction to the original place, generating a minimum environmental impact with the support of natural marine and coastal processes. The process design criteria are based on engineering guidelines, sampling, and characterization of eleven black sand samples. Using conventional techniques, the water content, granulometric distribution, particle size, and semi-quantitative Fe–Ti oxide concentration were determined for the different sand samples. It is estimated that Fe–Ti oxide production may reach 5.835 metric tons per day (5.835 mtpd) with a magnetic content of 97.50%, starting from 100 mtpd of black sands. Based on an economic analysis (Class V), a net profit of USD 835,875.63 is expected during the first year of production. Thus, the magnetic separation and enrichment of Fe–Ti oxides from iron titaniferous coastal sands exploitation should allow the commercial valorization of these resources in an eco-friendly way, i.e., with economic benefits and minimization of environmental impact in the source area. Full article

We investigated the potential of tailings generated from chrysotile asbestos fiber production as a source of iron, nonferrous metals, and gold. We proposed the use of granulometric separation and systematically examined different enrichment processes, namely magnetic separation, gravity concentration, and enrichment using a Knelson concentrator, to extract the valuable components. The characterization of the initial tailing samples revealed that it comprises primarily of serpentine, brucite, antigorite, hematite, vustite, sillimanite, and magnesium oxide. Using the suggested enrichment process, we isolated gold, chromite, and nickel-cobalt concentrates as valuable products in addition to magnetite. The new approach exhibited high separation efficiency for iron, nonferrous metals, and gold, allowing their satisfactory extraction. Full article