Mining Residues Research Articles

Mining Waste as an Eco-Friendly Adsorbent in the Removal of Industrial Basazol Yellow 5G Dye and Incorporation in Mortars

The circular economy seeks to better use materials and minimize waste generation. This article evaluated the use of granite rock powder, a mining residue, as an adsorbent for the Basazol Yellow 5G (BY5G) dye and the reuse of the residue generated by the by treating this effluent in construction products. Characterization of the adsorbent material by N2 physisorption indicated a surface area of 1514 m2 g−1. Energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD) confirmed the presence of silica in the sample and the absence of amorphous halos. The kinetic study showed a removal of approximately 98% at 298 K, and the pseudo-second-order model obtained the best fit. The adsorption isotherm satisfied the Langmuir model and was consistent with the L-type isotherm. The negative value of the Gibbs energy (ΔG°) and the positive value of the enthalpy (ΔH°) indicate that the process is spontaneous and endothermic. The activation energy (Ea) indicates the occurrence of chemical adsorption. The desorption rate was low for the adsorbate, demonstrating the possibility of using residual adsorbent material as a filler in mortar and concrete. The material did not exhibit pozzolanic characteristics and, even after adsorption, it showed favorable results when replacing 10% of the cement with GRP viable for use in civil construction even after the adsorption process.

Isolation and characterization mercury-resistant bacteria from gold mining in Lebong, Bengkulu

Lebong a regency in Bengkulu Province, possesses prominent potential in gold mining. This mining activity is conducted through amalgamation techniques, resulting in the deposition of mining residue containing mercury, subsequently leading to environmental pollution. Recognizing the hazards associated with such pollution, it becomes imperative to mitigate the presence of mercury through effective remediation strategies. Bioremediation, utilizing Mercury Resistant Bacteria (MRB), widely known as a viable method for mitigating mercury contamination. This study aims to isolate and characterize MRB to facilitate their potential application in addressing heavy metal pollution. This study involved the isolation and characterization of MRB through morphological observations, Gram staining, and biochemical tests (glucose, sucrose, fructose, citrate utilization, starch hydrolysis, urease activity, and catalase production). A total of 43 bacterial isolates were obtained from water, sediment, and soil samples collected from surrounding gold mining waste disposal. Among these isolates, bacteria resistant to mercury were selected on NA supplemented with various concentrations of mercury. Five potential candidates of MRB were identified, with the highest mercury concentration tested being 1000 ppm. Based on identification using Bergey’s Manual of Determinative Bacteriology, it was determined that four out of the five isolates belonged was Pseudomonas, while another belonged to Staphylococcus.

Preparation and characterization of eco-friendly composite based on geopolymer and reinforced with date palm fiber

This study investigated the effect of incorporating different amounts of date palm fiber (DPF) on the mechanical, physical, and structural properties of geopolymer composites. These composites were formulated by utilizing mining residue as the geopolymer matrix and PDF as a reinforcing agent. The synthesis procedure involved activating the mining residue with a highly concentrated NaOH solution to form the geopolymer matrix. Subsequently, the resulting matrix was blended with different proportions of DPF, ranging from 1% to 20% (wt/wt), and underwent a 28-day curing period under ambient conditions. Mechanical properties were assessed through compression (CS) and flexural (FS, FM) tests, while water absorption (WA) and thickness swelling (TS) were employed to evaluate physical properties. Additionally, FTIR spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) were used to elucidate changes in bonding nature, visualize matrix phases, analyze composition, and examine microstructure, respectively. The results demonstrated that incorporating an optimal amount of DPF fibers, of about 8% (wt/wt), yielded a geopolymer composite with outstanding mechanical properties. Both compressive and flexural strengths were twice as high compared to the geopolymer matrix, highlighting the effectiveness of DPF fiber as a reinforcing agent. However, the increase in fiber loading was associated with a decline in the physical properties of the composite, reaching an acceptable water WA value of 30% and TS value of 0.9% after 168-hours of immersion in water. Structural analysis using FTIR and XRD techniques suggested that mining residue, as an aluminosilicate raw material with a semicrystalline structure, undergoes a geopolymerisation reaction to a relatively lower extent after activation by a highly alkaline solution SEM images revealed a well-established matrix-fiber interface, providing an explanation for the achieved good mechanical and physical properties. EDX results showed an interesting composition of the geopolymer gel derived from mining residue with a significant amount of silicon and a moderate quantity of calcium and aluminum. This confirmed that the geopolymer gel formed primarily undergoes the C-A-S-H process, rather than N-A-S-H process, which is a positive indication of the geopolymer composite's mechanical properties.

Recycling of pyrite and gypsum mining residues through thermochemical conversion into valuable products

Pyrite-containing tailings pose an environmental challenge due to the risk of Acid Mine Drainage (AMD) upon storing if not properly managed. AMD can, however, be neutralized with alkali materials like lime which leads to the generation of gypsum that also ends up in the landfill. Instead of landfilling this residue, it can be recycled into potentially useful products. A proposed process involves decomposing pyrite, reduction of pyrrhotite, and finally conversion of gypsum to lime. This study evaluates the recycling/thermochemical conversion process of pyrite tailings and gypsum residues from the Boliden Aitik mine using thermodynamic modeling, simultaneous thermal analyses coupled with mass spectroscopy, and mineralogical composition identification. It was observed that pyrite can undergo complete decomposition into pyrrhotite and release elemental sulfur below 750 °C in an inert atmosphere. Furthermore, successful reduction of pyrrhotite was achieved through the application of biochar in the presence of lime at 950 °C in an inert atmosphere. The study also reveals that gypsum can be effectively converted to lime at 1200 °C in an inert atmosphere when accompanied by calcium sulfide (CaS). Moreover, the energy and material balance of the process was analyzed, considering the conversion of 1 ton of pyrite tailings. The products include 0.4 tons of iron powder, 2.7 tons of SO2 gas, 0.4 tons of CO2 gas, and 1.21 tons of excess active lime. The calculated energy consumption for this process was determined to be 2893 kWh.

Enhancing the Strength of Mine Residue Soil by Bioremediation Combined with Biopolymers

Traditional soil stabilization methods are usually associated with high energy consumption, carbon emissions, and long-term environmental impact. Recent developments have shown the potential use of bio-based techniques as eco-friendly alternatives for soil stabilization. The present work studies the effects of the addition of the biopolymers xanthan gum (XG) or carboxymethyl cellulose (CMC) to a mine residue soil, combined or not with biostimulation and bioaugmentation techniques, in terms of compressive stress–strain behavior. Unconfined compressive strength (UCS) tests were performed on previously disturbed samples (two cycles of percolation, extraction and homogenization) to evaluate if the biostimulation and bioremediation remain active in a real adverse scenario. The results allowed for us to conclude that both biopolymers, when applied individually (with a content of 1%), are effective stabilizers (CMC allows for unconfined compressive strength increases of up to 109%), showing better results for CMC than Portland cement. The biostimulation of the autochthonous community of the mine residue soil was revealed to be a non-effective technique, even when combined with the biopolymers. However, good results were observed when the bioaugmentation was combined with xanthan gum, with unconfined compressive strength improvements of up to 27%. The study revealed that these bio-based techniques are promising soil engineering techniques, offering environmentally friendly alternatives for sustainable soil stabilization and contributing to a greener and more sustainable future.

Bioleaching of polymetallic sulphidic mining residues: influence of increasing solid concentration on microbial community dynamics and metal dissolution

Within the European research project NEMO, a bioleaching strategy was developed for efficient metal extraction from bioleach residue currently heap-leached at Sotkamo (Finland) that still contains sulphidic minerals and valuable metals (Ni, Zn, Co, Cu). The strategy of gradually increasing the solid content with 5% steps allowed the adaptation of the consortium up to 20% (w/w) solid content, with efficient metal dissolution and same dominant bacteria. Largest proportions of Sulfobacillusthermosulfidooxidans while Eh increased suggested it to be most involved in iron oxidation. Acidithiobacilluscaldus was rather found when pH stabilized, in line with a production of protons from sulphur oxidation that maintained low pH. ‘Acidithiomicrobium’ P2 was favoured towards the end of the runs and at 20% (w/w) solids possibly due to its tolerance to Ni. The use of gene abundance to evaluate biomass in the pulp provided complementary results to classical cell counts in the liquid phase, and suggested a key role of bacteria associated to mineral particles in iron oxidation. Scaling-up in 21-L stirred-tank reactor at 20% (w/w) solids had no detrimental effect on bioleaching and confirmed metal extraction rates. ‘Acidithiomicrobium’ P2 and Sb. thermosulfidooxidans remained main actors. However, the biological activity was considerably reduced at 30% (w/w) solid concentration, which may be due to a too drastic environmental change for the bacteria to adapt to higher solid concentration. Efficient bioleaching of Sotkamo bioleaching residue at high solid concentration was demonstrated, as well as the robustness of the selected moderately thermophilic consortium, at laboratory and pilot scales.

Th-232 Radiological Aspects of Carbonate Niobium Mining Waste Use as Agricultural Amendment

The use of mining residues in agriculture may be possible, as long as there be previous studies in different areas, one of them being the analysis of the involved radionuclides behavior. This study determined the concentrations of 232Th activity in soil, soil treated with lime, soil with carbonate residue from niobium mining, soil with the mixture of lime and carbonate, in two moments. The transfer factor of 232Th from the soil to the plant was analyzed, in this case, lettuce (n=20), in the different types of treatment and in two moments. The addition of carbonate to the soils did not significantly alter the levels of radioactivity for 232Th radionuclide in lettuce. The effective dose resulting from the lettuce ingestion varied from 0.09 to 0.3 µSv y-1.

Study of The Impact of Limestone Mining on Environmental Damage in Klapanunggal Village of Bogor Regency

Klapanunggal Village is one of the villages which is one of the places for limestone mining to be carried out. The existence of limestone mining which has been operating since 1970 has had a direct impact on the environment of the surrounding community. The purpose of this study is to determine the impact of limestone mining on environmental damage in Klapanunggal Village and to find out the efforts of the local government to reduce the negative impacts of illegal limestone mining in Klapanunggal Village , Bogor Regency. This research is a type of descriptive research. The research results obtained are damage and changes in landscapes, destruction of habitats and ecosystems in limestone hills/mountains, stagnant water or ponds resulting from mining residues, damaged and perforated road conditions, air pollution, and noise. As for the efforts of the government was a 1000 tree planting program but only in a few locations and also carried out road casting in several road areas.

Turning waste into profit: Circular economic optimization of quartz sand from tin mining and processing

This paper analyzes whether the mining industry can apply circular economy principles in its investment, using two business scenarios of the circular economy. Scenario A utilizes quartz sand from tin mining residues and then processes it into concrete sand. Meanwhile, Scenario B is similar to Scenario A in the first stage, but the residue produced from the first stage is reprocessed to produce concrete sand. To compare the economic feasibility of both scenarios, this study applies a discounted cash flow technique and an incremental analysis. Material flow analysis investigates the circularity and productivity from resource utilization in every design. The two business scenarios are economically viable, but Scenario B is better than Scenario A. NPV of Scenarios A and B are US$ 513 thousand and US$ 322 thousand, respectively. The NPVB-A is US$ 147, whereas the IRR of Scenario A is 26.24 % and Scenario B is 34.05 %. The circularity of Scenarios A is 0.86 with a productivity of US$1.62/m3, and the circularity of Scenario B is 0.94 with a productivity of US$1.80/m3. Therefore, Scenario B is more efficient than that of Scenario A. Eventually, implementations of the circular economy principles in the mining industry are possible. These results can become a consideration for investors to innovate through circular economy approaches in their mining business for sustainable production and consumption purposes.

Technospheric mining of critical and strategic metals from nickel slag – Leaching with citric acid and hydrogen peroxide

Critical and strategic metals (CSMs), such as cobalt (Co) and nickel (Ni), are fundamental components of the high technology industry. Securing the supply of CSMs is fast becoming a priority for nations. Thus, secondary sources such as mine wastes, slags, tailings, and residues are being exploited to extract CSMs since they contain notable amounts of those metals. Recovering valuable metals from secondary sources can be categorised as technospheric mining. In this study, the extraction of cobalt and nickel from nickel slag was examined using a combination of an organic acid, citric acid, and hydrogen peroxide as the oxidant. Optimum conditions consisted of 1 M citric acid, 0.5% (v/v) hydrogen peroxide, at a temperature of 60 °C, a pulp density of 2.5%, a particle size of −100 + 75 μm, and an agitation speed of 400 rpm, for a period of 6 h. At the optimum conditions, 84.0% Ni and 91.7% Co were extracted from flash furnace (FF) slag, and 65.0% Ni and 99.1% Co from converter (CV) slag. It is expected that a combination of citric acid and hydrogen peroxide created peroxycitric acid in the solution, which is a strong oxidant and a key factor in the dissolution of the metals. The leach residue from FF slag showed a porous surface resulting from preferential dissolution within the slag structure. The residue from the converter (CV) slag mainly consisted of magnetite as a result of the dissolution of fayalite (Fe2SiO4). The kinetic studies demonstrated that the dissolution of Ni and Co from FF slag is controlled by diffusion. On the other hand, a rate controlling factor for Ni from CV slag is mixed control and for Co is a chemical reaction. Based on the temperature varied experiments, the calculated activation energy for Ni and Co from FF slag were 34.4 kJ/mol and 27.6 kJ/mol, respectively. The activation energies for the leaching of Ni and Co from the CV slag were 16.1 kJ/mol and 23.7 kJ/mol, respectively.

Earlier biomarkers in fish evidencing stress responses to metal and organic pollution along the Doce River Basin

The Doce River Basin (DRB) represents a well-described watershed in terms of contamination by metals, especially after a major environmental disaster of a mining tailing dam failure. Despite the massive mortality of the ichthyofauna, very few studies addressed the risks to the health of wild fish exposed to complex mixtures of pollutants from multiple sources. The present study proposed to investigate earlier responses of fish for assessing the impacts of multiple sources of pollution, considering: different niches of fish and target organs; and the influence of seasonality, associated with their probable sources of pollution. To achieve that, fish were collected along the DRB, and biomarkers responses were assessed in target organs and correlated with the levels of inorganic and organic contaminants. As one of the most prominent responses, fishes from the Upper DRB showed the highest expression of the metallothionein and oxidative stress parameters which were related to the higher levels of metals in this region due to the proximity of mining activities. On the other hand, higher levels of DNA damage and increased AChE activity from fish sampled in the Mid and Lower DRB were more associated with organic contaminants, from other sources of pollution than mining residues. The integrated biomarker responses also revealed seasonal variations, with higher values in fishes from the dry season, and pelagic fish showing greater variation within the seasons. The multivariate analysis integrating suitable biomarkers with chemical data represented an adequate strategy for assessing the ecological risks in the DRB, allowing the identification of distinct spatio-temporal impacts from multiple sources of contaminants. The continued exposure of the ichthyofauna representing future risks reinforces the need for ecological restoration and the protection of the fauna from the Doce River.

Production of sintered glass-ceramic composites from low-cost materials

Considering that wastes are harmfull for the environment and human health due to certain physical, chemical and biological reasons; the necessity of systematic implementation of waste management comes to the fore. Waste management provides advantages to for industrial manufacturing with less pollut on, cheaper and competitively superior products. With the waste recycling, the needs for raw materials and the impact of production on the environment will decrease. This study proposed to produce low-cost sintered glass-ceramic composite by adding a mixture of molten mining tailings, recycled glasses and alumina platelets at different rates. The results showed that glass-ceramic composite made by 50 wt % molten tailings, 25 wt % recycled borosilicate glass and 25 wt % alumina platelets exhibited the best properties (2.39 g/cm3 bulk density, 0.22 ± 0.01% water absorption and 84± 9 MPa bending strength). In this study, considering the consumptions of raw material resources, it was seen that glass and mine residues can be used as secondary raw materials in glass ceramic composite production when cost and environmental issues are matter.

Impact of Limestone–Metakaolin Ratio on the Performance and Hydration of Ternary Blended Cement

Once sulfates become limited, the interaction of limestone with metakaolin (MK) is initiated, resulting in the formation of carboaluminates in a blended cement system. In this study, two different types of MKs (sourced from coal mining residue and soft clay) were adopted to examine limestone–MK ratios of 1:8, 1:4, 1:2, 1:1, and 2:1, by fixing the cement and MK content at 55% and 15%, respectively. The optimal limestone–MK ratio of 1:4 was found (equal to limestone content of 3.8%) to achieve the highest compressive strength of 60 MPa due to the formation of more carboaluminate content in both MK blended cement systems. This finding was corroborated with the thermodynamic modeling that the highest hydrates volume was achieved at the optimal limestone–MK ratio of 1:4. An overdosage of limestone reduces its reaction degree, reflecting the fact that excessive limestone content could only acts as filler in the system.

Immobilization of Pb and Zn leached from mining residue materials in Kabwe, Zambia: Performance of calcined dolomite in column experiments

Legacy Pb-Zn mine in Kabwe, Zambia, has left massive stockpiles of mining residue materials (MRM) that contain potentially toxic elements, such as lead (Pb) and zinc (Zn), which pollute the environment. In situ remediation of the contaminated area is an attractive technique for immobilizing hazardous metals. In this study, the efficacy of modified dolomite, i.e., calcined dolomite (CD), was evaluated by mixing with the MRM at 1, 5, and 10 % ratios (CD1, CD5, and CD10, respectively). The leaching of hazardous metals, Pb and Zn, from the MRM was assessed by four-column experiments. Measurements of mineralogical and chemical constituents of the MRM, sequential extraction, and thermodynamic modeling of the leachates were carried out to determine the attenuation mechanisms. Sequential extraction results indicated that the leachable Pb and Zn in the MRM were mainly from the exchangeable and carbonate fractions. Furthermore, the results showed that the effluents from the column with MRM (CD0) exceeded the Zambian effluent regulatory values throughout 30 weeks of the experimental period. The introduction of the CD into the MRM increased effluent pH and decreased the leaching concentrations of Pb and Zn. The CD5 was enough to decrease the leaching concentrations of both hazardous metals below the Zambian effluent standard by prohibiting the release of Pb and Zn via the dissolution of carbonate minerals and retaining them in the carbonate fraction. The saturation indices of Pb and Zn suggest that the retention mechanisms by the CD accredit to precipitation, co-precipitation, and adsorption reactions. These results present an effective and inexpensive immobilization technology for hazardous wastes in abandoned mines.

Categorization of Mining Materials for Restoration Projects by Means of Pollution Indices and Bioassays

Sulfide mining wastes may lead to severe environmental and human health risks. This study aims to use geochemical and ecotoxicological indicators for the assessment of the ecological risks of potentially toxic elements (PTEs) in the San Quintín mining group to categorize wastes prior to mining restoration. Ecotoxicity was evaluated using crustacean (Dahpnia magna, Thamnocephalus platyurus) and algae (Raphidocelis subcapitata) bioassays. The geochemical and mineralogical results suggested that the mining residues underwent intense weathering processes, with active processes of acidity generation and metal mobility. Total PTEs concentrations indicated that the mining materials were extremely polluted, with Pb, Zn and Cd geoaccumulation index (Igeo) values higher than 5 in more than 90% of the samples. The pollution load index (PLI) showed average values of 18.1, which classifies them as very highly polluted. The toxicity tests showed a higher toxicity for plants than crustaceans, being the highest values of toxicity related to toxic elements (Pb, Cd and Zn), electrical conductivity and to pH. This paper presents for the first time the combination of indices in the categorization of mining waste prior to its restoration. The combination of them has made it possible to categorize the waste and adapt the restoration and remediation procedures.

Exposure to coal mining can lead to imbalanced levels of inorganic elements and DNA damage in individuals living near open-pit mining sites

Coal mining activities are considered harmful to living organisms. These activities release compounds to the environment, such as polycyclic aromatic hydrocarbons (PAHs), metals, and oxides, which can cause oxidative damage to DNA. In this study, we compared the DNA damage and the chemical composition of peripherical blood of 150 individuals exposed to coal mining residues and 120 non-exposed individuals. Analysis of coal particles revealed the presence of elements such as copper (Cu), aluminum (Al), chrome (Cr), silicon (Si) and iron (Fe). The exposed individuals in our study had significant concentrations of Al, sulfur (S), Cr, Fe, and Cu in their blood, as well as hypokalemia. Results from the enzyme-modified comet assay (FPG enzyme) suggest that exposure to coal mining residues caused oxidative DNA damage, particularly purine damage. Furthermore, particles with a diameter of <2.5 μm indicate that direct inhalation could promote these physiological alterations. Finally, a systems biology analysis was performed to investigate the effects of these elements on DNA damage and oxidative stress pathways. Interestingly, Cu, Cr, Fe, and K are key nodes that intensely modulate these pathways. Our results suggest that understanding the imbalance of inorganic elements caused by exposure to coal mining residues is crucial to understanding their effect on human health.

Environmental and Health Risk Assessment of Soil Adjacent to a Self-Burning Waste Pile from an Abandoned Coal Mine in Northern Portugal

Abandoned mines and disposal of mining residues can be responsible for the release of potentially toxic elements (PTEs) into the environment causing soil and water contamination, with potential ecological damage and human health hazards. The quantification of the apportionment of PTEs in soils and the study of the associated ecological and human health risks are essential. This study aims to assess the environmental and human health risk of the soils surrounding an abandoned coal mine in São Pedro da Cova, whose waste pile has been affected by self-combustion for over 17 years. The soil environmental characterization of the study area regarding PTEs was accessed by different pollution indices, considering the elementary crustal abundance and the determined regional soil geochemical background. The soil contamination degree was evaluated using indices such as the contamination factor (Cf) and geoaccumulation index (Igeo), inferred for all soil samples, and the potential ecological risk index (PERI) was also accessed. The human health risk was evaluated for adults and children, considering the non-carcinogenic and carcinogenic risks. The pollution indices calculated for the PTEs using distinct reference values showed significant differences, resulting in lower pollution indices when using the regional reference values. The regional background proved to be a much more reliable geochemical baseline for environmental assessment. Regarding Igeo, the soils were found to be unpolluted to moderately polluted for most of the studied PTEs. The determined PERI for the soils surrounding the abandoned mine classifies them as low ecological risk. The evaluation of the non-carcinogenic and carcinogenic risks, resulting from exposure to the studied soils, suggests that there is no potential human health risk for children or adults regarding the considered PTEs.

A System Analysis of a Bio-Hydrogen Production System Using Granulated Mine Residue as a H2S Adsorbent

An energy production system that combines biomass and fuel cells produces much energy with minimal environmental impact. However, the hydrogen sulfide (H2S) contained in gasified biomass degrades fuel cell performance, thus negating the advantages of this combination. In this study, the removal of H2S by adsorption after biomass gasification was investigated. Metal oxides with high adsorption performance are common H2S adsorbents. However, they have a significant environmental impact in terms of metal depletion, which is an environmental impact indicator. Therefore, neutralized sediment materials from mine drainage treatments can be used as H2S adsorbents. A previous study found that the adsorption performance of H2S adsorbents is equivalent to that of metal oxides, especially in the high-temperature zone (300 °C), and the environmental impact is considerably lower than that of metal oxides. However, because the neutralized sediment is a powder (Φ 4.5 μm on average), there is a possibility that the gas will not flow due to the pressure drop when it is used in a large adsorption column. Therefore, in this study, we propose the use of granulated neutralized sediments for practical plant operations. No studies have investigated the adsorption performance of granulated neutralized sediment through experiments or quantitatively investigated the effect of using waste material as a H2S adsorbent to reduce the environmental impact of hydrogen production. Based on these data, the sulfur capture capacity of the granulated neutralized sediment was experimentally investigated. The extent to which the environmental impact of the hydrogen production system could be reduced when granulated neutralized sediment was used as the H2S adsorbent was assessed. Note that the granulated neutralized sediment is formed with about a Φ 0.56–1.25 mm diameter. The granulated neutralized sediment exhibited approximately 76.8% of the adsorption performance of zinc oxide (ZnO) on a conventional adsorbent. In terms of the LCA, the global warming potential (GWP) and the abiotic depletion potential (ADP) were improved by approximately 0.89% (GWP) and 55.3% (ADP) in the entire hydrogen production process. This study demonstrated that the use of waste materials can significantly reduce the environmental impact on the entire system.

Unsupervised annual change detection from optical-SAR fused satellite image time-series using 3D-CAE

ABSTRACT Satellite images are widely used for change detection in various applications, like, agricultural and forest cover area monitoring and management, urban planning, disaster management etc. which require prior information about the timeline of changes. However, it is very challenging to identify precise timeline of changes and to acquire corresponding labelled reference of changes. Considering this, Convolutional Auto-Encoder (CAE)-based approaches has been proposed for unsupervised change detection from bi-temporal remote sensing images. However, these type of approaches require prior knowledge about the exact moment the change occurs in order to employ the bi-temporal images, one pre-change and one post-change. This work introduces the utilization of satellite image time-series (SITS) data in a Joint 3D CAE-based unsupervised approach to detect annual changes. Our study focuses on a mining area where the changes mostly occurs due to tailings, waste and ore deposit, mining pit, mining residue, and so on. Here, we have explored Synthetic Aperture Radar (SAR) (i.e. Sentinel-1) data along with optical (i.e. Sentinel-2) data, since optical data alone was not able to detect all the changes. The recall of detected change areas during 2016–2018 has improved by about 16% with the use of combination of Sentinel-1&2 data as compared to utilization of only Sentinel-2 images.

Analysis of the cytotoxic and genotoxic effects in a population chronically exposed to coal mining residues

During coal mining activities, many compounds are released into the environment that can negatively impact human health. Particulate matter, polycyclic aromatic hydrocarbons (PAHs), metals, and oxides are part of the complex mixture that can affect nearby populations. Therefore, we designed this study to evaluate the potential cytotoxic and genotoxic effects in individuals chronically exposed to coal residues from peripheral blood lymphocytes and buccal cells. We recruited 150 individuals who lived more than 20 years in La Loma-Colombia and 120 control individuals from the city of Barranquilla without a history of exposure to coal mining. In the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, significant differences in the frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD), and apoptotic cells (APOP) were observed between the two groups. In the buccal micronucleus cytome (BM-Cyt) assay, a significant formation of NBUD, karyorrhexis (KRX), karyolysis (KRL), condensed chromatin (CC), and binucleated (BN) cells was observed in the exposed group. Considering the characteristics of the study group, a significant correlation for CBMN-Cyt was found between NBUD and vitamin consumption, between MN or APOP and meat consumption, and between MN and age. Moreover, a significant correlation for BM-Cyt was found between KRL and vitamin consumption or age, and BN versus alcohol consumption. Using Raman spectroscopy, a significant increase in the concentration of DNA/RNA bases, creatinine, polysaccharides, and fatty acids was detected in the urine of individuals exposed to coal mining compared to the control group. These results contribute to the discussion on the effects of coal mining on nearby populations and the development of diseases due to chronic exposure to these residues.