Search Results (27)

Understanding the environmental pathways and surface modification of beach sand grains is essential for reconstructing coastal dynamics and assessing the suitability of natural sands for engineering applications. This study applies a multiproxy approach—integrating grain roundness classification, SEM microtextural analysis, and XPS surface chemistry—to beach sediments from four coastal sectors of Latvia: Liepaja, Ventspils, Riga, and Salacgrīva. The results reveal clear spatial differences in grain maturity, abrasion signatures, biological imprinting, and nanoscale surface composition. Liepaja is characterised by sub-rounded to rounded grains with abundant percussion pits and abrasion surfaces, indicating prolonged high-energy wave reworking. Ventspils retains angular grains with fresh conchoidal fractures, reflecting rapid sediment renewal from glacial and coastal sources. Riga exhibits weak abrasion and hydrated particulate coatings typical of low-energy brackish environments. Salacgrīva displays strong fluvial influence, including persistent diatom and algal microtextural features and elevated oxygenated carbon and metal-associated XPS signals. These findings demonstrate strong coupling between grain-surface microtextures and surface chemistry and reveal distinct sedimentary fingerprints linked to environmental setting. The multiproxy framework presented here improves understanding of Baltic coastal sediment pathways and provides a preliminary basis for future evaluation of natural sands in filtration and other environmental engineering applications. Full article

Metallurgical chromium slag is a hazardous by-product generated during the production of chromium salts and metallic chromium, containing significant amounts of leachable Cr(VI), which poses severe environmental and human health risks. To address this challenge, this study presents an integrated “alkaline roasting, water leaching with impurity removal, glucose reduction and vacuum calcination” process for its direct preparation to nano-pigment-grade Cr₂O₃. The reduction process was systematically optimized by investigating the effects of critical parameters: glucose dosage, HCl concentration, reduction temperature and time. Optimal conditions were established as 2.5 g of C₆H₁₂O₆, 20 mL of 12 M HCl, 55 °C and 4 h, achieving the Cr(VI) reduction efficiency of 99.66%. Comprehensive characterization of the final product via XRD, SEM-EDS and XRF confirmed its high quality. The Cr₂O₃ exhibited a purity of 99.31%, well-developed crystallinity and a uniform sub-micron particle size distribution, fully meeting industrial standards for pigment applications. By substituting conventional hazardous reductants with glucose, this route demonstrates enhanced safety, environmental compatibility and cost-effectiveness. The proposed methodology not only provides a practical and scalable solution for the valorization of hazardous chromium slag but also contributes to the advancement of green processing technologies in the metallurgical sector, supporting the transition towards a circular economy. Full article

Electricity access deficits remain acute in Sub-Saharan Africa (SSA), where more than 600 million people lack reliable supply. Green hydrogen, produced through renewable-powered electrolysis, is increasingly recognized as a transformative energy carrier for decentralized systems due to its capacity for long-duration storage, sector coupling, and near-zero carbon emissions. This review adheres strictly to the PRISMA 2020 methodology, examining 190 records and synthesizing 80 peer-reviewed articles and industry reports released from 2010 to 2025. The review covers hydrogen production processes, hybrid renewable integration, techno-economic analysis, environmental compromises, global feasibility, and enabling policy incentives. The findings show that Alkaline (AEL) and PEM electrolyzers are immediately suitable for off-grid scenarios, whereas Solid Oxide (SOEC) and Anion Exchange Membrane (AEM) electrolyzers present high potential for future deployment. For Sub-Saharan Africa (SSA), the levelized costs of hydrogen (LCOH) are in the range of EUR5.0–7.7/kg. Nonetheless, estimates from the learning curve indicate that these costs could fall to between EUR1.0 and EUR1.5 per kg by 2050, assuming there is (i) continued public support for the technology innovation, (ii) appropriate, flexible, and predictable regulation, (iii) increased demand for hydrogen, and (iv) a stable and long-term policy framework. Environmental life-cycle assessments indicate that emissions are nearly zero, but they also highlight serious concerns regarding freshwater usage, land occupation, and dependence on platinum group metals. Namibia, South Africa, and Kenya exhibit considerable promise in the early stages of development, while Niger demonstrates the feasibility of deploying modular, community-scale systems in challenging conditions. The study concludes that green hydrogen cannot be treated as an integrated solution but needs to be regarded as part of blended off-grid systems. To improve its role, targeted material innovation, blended finance, and policies bridging export-oriented applications to community-scale access must be established. It will then be feasible to ensure that hydrogen contributes meaningfully to the attainment of Sustainable Development Goal 7 in SSA. Full article

Cold Spray Additive Manufacturing (CSAM) is a solid-state process that is being increasingly used for structural repairs in aerospace and energy sectors. It enables the deposition of dense material at low temperatures by accelerating metal particles to supersonic velocities, thereby reducing thermal distortion. However, the structural integrity of CSAM repairs—particularly at the interface between the deposited layer and the substrate—remains a critical concern. Various post-treatments and characterization methods have been explored to optimize performance. While X-ray Computed Tomography (XCT) is effective for sub-surface inspection, it cannot be applied in situ during mechanical testing. Digital Image Correlation (DIC), a surface-based method, also lacks sub-surface sensitivity. To address this, Infrared Thermography (IRT) was employed alongside DIC during the tensile and fatigue testing of aluminum CSAM-repaired specimens. A cooled IRT camera operating at 200 FPS captured thermal data, with lock-in processing subsequently applied in post-processing. IRT successfully detected early interfacial damage and enabled the tracking of crack propagation, which was later confirmed through fracture surface analysis. This extended abstract presents findings from fatigue tests using IRT. Full article

This study focuses on the carbon emissions of key industries in Henan Province, employing techniques of seasonal adjustment, frequency transformation, and statistical modeling to construct an industry-level “Electricity–Energy–Carbon” model to aid in the high-frequency monitoring of carbon emissions in the province’s industries. Based on relevant data, this research performs high-frequency calculations of carbon emissions from energy consumption in 34 typical industries and from the production processes of 53 typical sub-categories in the industrial sector of Henan. The findings reveal the following: Firstly, industrial energy consumption in Henan accounts for over half of the total provincial energy consumption, with most months seeing proportions around 60%. Industries such as energy, non-ferrous metals, building materials, steel, chemicals, petrochemicals, and paper making contribute to over 80% of the industrial energy consumption’s carbon emissions, often nearing 90% in most months. Secondly, among the major industries, such as non-ferrous metals, chemicals, building materials, and steel, there is a dual challenge of being restricted under the “high energy consumption and high emissions” project while also being required to build key industrial bases, leading to fluctuating trends in historical annual carbon emissions data. Thirdly, six sub-categories, namely plastic products, cement, flat glass, steel, ten types of non-ferrous metals, and alumina, have significant carbon emissions in their production processes, accounting for about 72.3% of the total production-related emissions. Full article

This study examines the environmental impacts of informal e-waste recycling processes in Agbogbloshie, Ghana, which is one of the most notorious e-waste recycling sites in sub-Saharan Africa. Despite being unsafe and unorganized, the informal sector is still actively involved in dismantling, extracting, and disposing of e-waste in unauthorized locations on a considerably large scale. However, the academic research on the environmental consequences of informal recycling practices is limited. Soil and groundwater samples for five important and representative informal e-waste recycling processes and one related oil process were collected and analyzed to determine heavy metal-, PBDEs, PCBs, CBs, and PAHs concentrations. Contamination indices were used to assess and compare the effects of informal recycling processes, thereby providing a geochemical evaluation of soil conditions. As a result, the manual dismantling of CRT and ICT devices is the major source of heavy metal pollution. Furthermore, the burning of e-waste plastic for waste reduction purposes and the oil collection process substantially contribute to the input of organic pollutants. Regulatory measures for CRT and ICT recycling would result in an 85% reduction of heavy metals and the enforcement of a compulsory collection system for plastic and oil would eliminate 86% of the organic pollutants. Full article

The mining industry is the leading supplier of raw materials in modern society. This sector of human activity has experienced a severe crisis due to the energy transition and has been revived in recent years due to the need for critical metals that are essential in the post-coal era. In underground and open pit mining, processes such as extraction, transportation, safety, underground ventilation, waste management, and rehabilitation are of major importance, and their “design” is critical to the economic survival of the mine. All the above processes required to operate a mine are strongly reminiscent of an example of nature’s workman: the ant. The sympatric insect uses the same processes as the ones aforementioned during the creation of its nest. The ants dig to “extract material from the ground”, and they transport this material from the nest‘s site to the waste deposition location. The ants ensure the safety of the underground opening and the proper ventilation needed for them to live there for a long time. This article attempts to identify the relations between all the above processes and sub-processes, and how human mining and ant colony development correlate with each other. Furthermore, we examine how an ant colony has aided in the development of mining technology, and what more humans can learn and adopt from a “miner” that is 66 million years old, in order to improve their processes. Full article

Rare earth elements (REEs including Sc, Y) are critical minerals for developing sustainable energy sources. The gradual transition adopted in developed and developing countries to meet energy targets has propelled the need for REEs in addition to critical metals (CMs). The rise in demand which has propelled REEs into the spotlight is driven by the crucial role these REEs play in technologies that aim to reduce our carbon footprint in the atmosphere. Regarding decarbonized technologies in the energy sector, REEs are widely applied for use in NdFeB permanent magnets, which are crucial parts of wind turbines and motors of electric vehicles. The underlying motive behind exploring the energy and carbon footprint caused by REEs production is to provide a more complete context and rationale for REEs usage that is more holistic. Incorporating artificial intelligence (AI)/machine learning (ML) models with empirical approaches aids in flowsheet validation, and thus, it presents a vivid holistic picture. The energy needed for REEs production is linked with the source of REEs. The availability of REEs varies widely across the globe. REEs are either produced from ores with associated gangue or impurities. In contrast, in other scenarios, REEs can be produced from the waste of other mineral deposits or discarded REEs-based products. These variations in the source of feed materials, and the associated grade and mineral associations, vary the process flowsheet for each type of production. Thus, the ability to figure out energy outcomes from various scenarios, and a knowledge of energy requirements for the production and commercialization of multiple opportunities, is needed. However, this type of information concerning REEs production is not readily available as a standardized value for a particular material, according to its source and processing method. The related approach for deciding the energy and carbon footprint for different processing approaches and sources relies on the following three sub-processes: mining, beneficiation, and refining. Some sources require incorporating all three, whereas others need two or one, depending on resource availability. The available resources in the literature tend to focus on the life cycle assessment of REEs, using various sources, and they focus little on the energy footprint. For example, a few researchers have focused on the cumulative energy needed for REE production without making assessments of viability. Thus, this article aims to discuss the energy needs for each process, rather than on a specific flowsheet, to define process viability more effectively regarding energy need, availability, and the related carbon footprint. Full article

Kenya is an East African country with the third-largest economy in sub-Saharan Africa. The demand for metals and minerals continues to increase due to urbanization, population rise, and new infrastructure growth in different countries. Kenya formally confirmed the discovery of oil and various minerals in April 2013, launching itself as a new player in Africa’s rapidly expanding extractive sector. This review paper highlights the mining status in Kenya and the role of hydrometallurgical and flotation processes in the recovery of deficit metals from ores and mine wastes. The nation’s 2030 Vision is anticipated to benefit greatly from the proceeds from the sale of oil, gas, and valuable metals. Because Kenya was originally mapped as an agricultural region, less mineral prospecting was done in earlier times. The country’s mining industry is now dominated by the manufacture of non-metallic goods, and it is largely neglected for minerals. One of the most serious problems for the mining industry in Kenya is the production of tailings that hold strategic metals. The material is already ground, which means the most energy-consuming process has been already applied, and chemical engineering processes like leaching are more feasible at this point. Hydrometallurgical and flotation recovery of valuable metals from wastes, high and low-grade ores, or tailings is essential. The resources will be preserved, which ensures sustainability in the growth of the mining industry. Full article

Abandoned mining–metallurgical sites can significantly impact the environment and human health by accumulating heavy metals in aquatic ecosystems. The water in the sub-basin near an abandoned smelting facility in the city of La Oroya, Peru, is primarily used for pisciculture. The objective of this study was to assess the risk to human health from exposure to heavy metals via dietary intake of rainbow trout (Oncorhynchus mykiss) in the influence area of a smelting facility located in the central Andean region of Peru. The bioconcentration factor, biosediment accumulation factor, and consumption risks were evaluated using the Monte Carlo method. The results showed that the concentrations of elements (Zn > Pb > Cu > As) in rainbow trout muscle did not exceed the maximum limit (ML). However, the water significantly exceeded the ML for Pb in all sectors and As in the lower and middle parts of the river. The concentration of Pb in sediments also significantly exceeded the ML in the upper and lower parts of the river. Consequently, rainbow trout consumption in the study area presents risks to human health due to the bioaccumulation of heavy metals, with a 1.27% carcinogenic risk in samples from the lower part of the river. Full article

The current Waste Electrical and Electronic Equipment (WEEE) management system of the European Union to be applied in all member states was introduced in 2002 by the first WEEE directive (2002/96/EC). Since the beginning, the system was intended to improve the management of WEEE and promote circular economy principles in the sector. This study aims at evaluating the environmental and social impacts of the WEEE management system in Italy, with a special focus on collection and recycling in Campania Region (the third more populated Italian Region, Southern Italy). The Life Cycle Assessment (LCA) is jointly applied with the Social Life Cycle Assessment (S-LCA). All five categories of WEEE (R1 to R5) are considered in the assessment. The LCA results show that the extraction of metals and materials from 1 tonne of WEEE collection and recycling generates much lower environmental impacts than the extraction and refining of an equivalent amount of virgin resources. In particular, the results of the environmental LCA highlight that the treatment of 1 tonne of WEEE collected in the Campania Region provides the opportunity to recover several metals such as Aluminum, Iron, Steel and ferrous materials, Copper, Nickel, Lead, and precious metals (Gold, Silver, and Palladium). According to S-LCA, the collection and recycling of 1 tonne of WEEE provides positive impacts to the investigated sub-categories of recipients (i.e., local community and society), except in some cases where the collection may potentially generate negative impacts, expressed by a lower “safe and healthy living conditions” indicator in the local community sub-category. In particular, much more must be done to support small Municipalities towards better collection procedures and integration within the largest Regional and national WEEE valorization networks. Solutions are suggested to improve the transition of the WEEE management system towards a more just environmental and social circular economy model. Full article

The etiopathogenesis of amyotrophic lateral sclerosis (ALS) is still largely unknown, but likely depends on gene–environment interactions. Among the putative sources of environmental exposure are air pollutants and especially heavy metals. We aimed to investigate the relationship between ALS density and the concentration of air pollution heavy metals in Ferrara, northern Italy. An ecological study was designed to correlate the map of ALS distribution and that of air pollutants. All ALS cases diagnosed between 2000 and 2017 (Ferrara University Hospital administrative data) were plotted by residency in 100 sub-areas, and grouped in 4 sectors: urban, rural, northwestern and along the motorway. The concentrations of silver, aluminium, cadmium, chrome, copper, iron, manganese, lead, and selenium in moss and lichens were measured and monitored in 2006 and 2011. Based on 62 ALS patients, a strong and direct correlation of ALS density was observed only with copper concentrations in all sectors and in both sexes (Pearson coefficient (ρ) = 0.758; p = 0.000002). The correlation was higher in the urban sector (ρ = 0.767; p = 0.000128), in women for the overall population (ρ = 0.782, p = 0.000028) and in the urban (ρ = 0.872, p = 0.000047) population, and for the older cohort of diagnosed patients (2000–2009) the assessment correlated with the first assessment of air pollutants in 2006 (ρ = 0.724, p = 0.008). Our data is, in part, consistent with a hypothesis linking copper pollution to ALS. Full article

The heavy pressure to improve CO₂ emission control in industry requires the identification of key sub-sectors and the clarification of how they mitigate CO₂ emissions through various actions. Focusing on 30 Chinese provincial regions, this study quantifies the contribution of each industrial sector to regional CO₂ mitigation by combining the logarithmic mean Divisia index with attribution analysis and extract the key sectors of CO₂ mitigation for each region. Results indicate that during 2010–2019, significant emission reduction was achieved through energy intensity (74%) in Beijing, while emission reductions were attained through industrial structure changes for Anhui (50%), Henan (45%), and Chongqing (45%). The contribution to emission reduction through energy structures is not significant. The production and supply of power and heat (PSPH) is a central factor in CO₂ mitigation through all three inhibitive factors. Petroleum processing and coking (PPC) generally contributes to emission reduction through energy structures, while the smelting and pressing of ferrous metals (SPMF) through changes in industrial structures and energy intensity. PSPH and SPMF, in most regions, have not achieved the emission peak. Except in the case of coal mining and dressing (CMD), CO₂ emissions in other key sectors have almost been decoupled from industrial development. CMD effectively promotes CO₂ mitigation in Anhui, Henan, and Hunan, with larger contribution of PPC in Tianjin, Xinjiang, Heilongjiang, and that of smelting and pressing of nonferrous metals in Yunnan and Guangxi. The findings help to better identify key sectors across regions that can mitigate CO₂ emissions, while analyzing the critical emission characteristics of these sectors, which can provide references to formulating region- and sector-specific CO₂ mitigation measures for regions at different levels of development. Full article

Different types of metal oxide nanoparticles (NPs) are being used for wastewater treatment worldwide but concerns have been raised regarding their potential toxicities, especially toward non-targeted aquatic organisms including fishes. Therefore, the present study aimed to evaluate the toxicity of copper oxide (CuO) NPs (1.5 mg/L; positive control group) in a total of 130 common carp (Cyprinus carpio), as well as the potential ameliorative effects of fenugreek (Trigonella foenum-graecum) seed extracts (100 mg/L as G-1 group, 125 mg/L as G-2 group, and 150 mg/L as G-3 group) administered to fish for 28 days. Significant changes were observed in the morphometric parameters: the body weight and length of the CuO-NP-treated fish respectively decreased from 45.28 ± 0.34 g and 14.40 ± 0.56 cm at day one to 43.75 ± 0.41 g and 13.57 ± 0.67 cm at day 28. Conversely, fish treated with T. foenum-graecum seed extract showed significant improvements in body weight and length. After exposure to CuO NPs, a significant accumulation of Cu was recorded in the gills, livers, and kidneys (1.18 ± 0.006 µg/kg ww, 1.38 ± 0.006 µg/kg ww, and 0.05 ± 0.006 µg/kg ww, respectively) of the exposed common carp, and significant alterations in fish hematological parameters and oxidative stress biomarkers (lipid peroxidation (LPO), glutathione (GSH), and catalase (CAT)) were also observed. However, supplementing diets with fenugreek extracts modulated the blood parameters and the oxidative stress enzymes. Similarly, histological observations revealed that sub-lethal exposure to CuO NPs caused severe histomorphological changes in fish gills (i.e., degenerative epithelium, fused lamellae, necrotic lamellae, necrosis of primary lamellae, complete degeneration, and complete lamellar fusion), liver (i.e., degenerative hepatocytes, vacuolization, damaged central vein, dilated sinusoid, vacuolated degeneration, and complete degeneration), and kidney (i.e., necrosis and tubular degeneration, abnormal glomerulus, swollen tubules, and complete degeneration), while the treatment with the fenugreek extract significantly decreased tissue damage in a dose-dependent manner by lowering the accumulation of Cu in the selected fish tissues. Overall, this work demonstrated the ameliorative effects of dietary supplementation with T. foenum-graecum seed extract against the toxicity of NPs in aquatic organisms. The findings of this study therefore provided evidence of the promising nutraceutical value of fenugreek and enhanced its applicative potential in the sector of fish aquaculture, as it was shown to improve the growth performance and wellness of organisms. Full article

In the automotive sector, lightweight carbon/epoxy composites have shown their benefits compared to traditional metals, and they are used in several parts of vehicles, such as frames and chassis. In such sub-components, different cross-section geometries are utilized and the materials can be subjected to various loading combinations. Determining the precise damage development is of great importance to obtain improved designs, avoiding overdesigned parts and early failure. To that end, V-shape carbon/epoxy specimens have been experimentally characterized under both quasi-static and fatigue tensile loads. The potential of Digital Image Correlation (DIC) and Acoustic Emission (AE) for damage assessment is explored. Full article