Intensive gold mining activities in Ghana’s Ayanfuri enclave pose a significant threat to groundwater quality. To evaluate this impact, a hydrogeochemical assessment was conducted on 59 groundwater samples from community boreholes (n = 22), observation boreholes (n = 13), tailings storage facility (TSF) boreholes (n = 18), and embankments (n = 6). Analytical techniques included Piper diagrams, Gibbs plots, bivariate diagrams, Ficklin diagrams, geochemical modeling, and Net Acid Production Potential (NAPP) computations to characterize hydrogeochemical facies and dominant processes. The prevailing water type is Na-Mg-HCO₃, accounting for approximately 17% of all samples. Groundwater pH is generally below seven at all sampling sites, with the highest acidity in observation boreholes, likely due to hydromorphic dispersion of metal effluents. The groundwater samples consistently exhibited negative NAPP values, indicating that they can neutralize acidity and therefore pose a low risk of acid mine drainage (AMD). Approximately 93% of the samples fall within the Near-neutral Low-metal range on the Ficklin diagram, indicating stable water chemistry and further supporting a low AMD risk. However, 7% of the samples from sites located behind the TSF embankments and observation boreholes, with pH 5.2–5.9 and elevated potentially toxic elements (up to 18.1 ppm), fall within the Colorado AMD and Acid Low Metal zones, implying that sulfide oxidation outpaces neutralization at these sites. These areas pose a higher risk of generating acidic, metal-rich drainage, potentially mobilizing harmful elements, and degrading water quality. Ion exchange and silicate weathering dominate solute acquisition, while lithology and anthropogenic inputs influence spatial variability. This study underscores aquifer vulnerability in mining regions and calls for policy interventions integrating hydrogeochemical risk assessments into mining legislation and water governance. Continuous monitoring, community-based protection, and strict regulatory enforcement are recommended to safeguard groundwater for domestic and agricultural use.

Introduction

Metal scrap recycling plays a role in the circular economy, reducing reliance on primary metal production, which uses more energy; recycled metal requires only 5% of the energy. Mechanical sorting at shredder facilities recovers ferrous and non-ferrous metals from mixed scrap, conserving resources. To achieve circular economy objectives, the waste (SR) from these processes needs to be recovered. SR, a mix of metals, plastics, rubber, and other materials, poses a challenge in achieving a circular economy in scrap recycling. The sustainability of scrap recycling depends not only on metal recovery but also on alternative SR treatment. This study applies LCA to assess the environmental performance of mechanical sorting.

Method

LCA was performed on a shredder facility processing 7 kt annually. Using SimaPro with the CML-IA Baseline method and a 1-tonne functional unit, system boundaries included energy, emissions, and waste treatment, with recycling credits for avoided virgin production. Four scenarios were modelled: (S1) metal recovered, residues landfilled; (S2) metal and plastic recovered, remaining residues landfilled; (S3) metal recovered, residue incinerated; (S4) metal and plastic recovered, residue incinerated for energy.

Result
Metal recovery greatly reduces the environmental impacts of sorting, and the scenarios showed clear differences across the indicators. For Global Warming Potential, S1 had the highest impact at 8.77 kg CO2-eq, while S4 performed best at -17.34 kg CO2-eq due to avoided virgin production and energy substitution. The Human Toxicity indicator followed the same trend, with S1 showing the highest impact at -29.25 kg 1,4DBeq and S4 the lowest at -91.78 kg 1,4DB-eq. Acidification showed the best performance in S2 at -0.19 kg SO2-eq and the highest impact in S3 at -18.14 kg SO2-eq. For Fossil Fuel Depletion, S2 performed best at -147.28 MJ, while S3 showed the highest impact at -114.01 MJ.

Conclusions
The results demonstrate that combining material recovery with appropriate residue treatment significantly enhances environmental benefits compared to landfill-only.

2,4,6-Tribromophenol (TBP) and its transformation product, 2,4,6-tribromoanisole (TBA), are characteristic brominated aromatic compounds frequently detected in various aquatic systems. Their presence in the aquatic environment is associated with the low efficiency of conventional treatment methods to remove them. It is well documented in the literature that they can cause several detrimental effects, including toxicity to aquatic microorganisms and the formation of unpleasant odours that deteriorate water quality. Therefore, the main aim of the present study is to investigate alternative methods for the removal of both compounds from different aqueous matrices. The solar/chlorine process is a representative advanced oxidation process (AOP) that has been studied in recent years due to its potential applicability compared with other methods in this category.

Accordingly, the solar/chlorine process was, for the first time, evaluated for its ability to simultaneously degrade both brominated aromatic compounds at environmentally relevant concentrations. To evaluate the efficiency of the process, a combination of analytical techniques and biological assays was employed. According to the results, the solar/chlorine process was effective for the simultaneous removal of both compounds. In particular, >80% removal was achieved in approximately 30-45 minutes. Moreover, no acute toxicity or genotoxic effects were observed at the end of the process against microalgae and human lymphocytes, respectively.

Acknowledgements

This paper has been financed by E.Y.D.A.P. within the framework of the IKY-EYDAP Scholarship program academic year 2022-23.

Climate-driven ocean warming is facilitating the expansion of thermophilic invasive species such as Pinctada radiata in the Mediterranean Sea. This study examined the species’ physiological responses to thermal gradients near the Delimara Power Station (Malta) to evaluate its potential as an early climate-change bioindicator. Specimens were collected from three sites along a temperature gradient (26.3 °C, 27.1 °C, 28.5 °C), and gill and adductor muscle tissues were analyzed for redox state biomarkers (ROS, oxidative damage to lipids—HPs and proteins—CO), antioxidant capacity (in vitro susceptibility to oxidants—∆HPs, total antioxidant capacity—TAC, glutathione peroxidase—GPx, and glutathione reductase—GR activity), and aerobic metabolism (cytochrome c oxidase, COX). Data were statistically analyzed by one-way ANOVA followed by Tukey’s post hoc test. Gill and muscle tissues responded differently to warming. The gills showed little change at 27.1 °C, but at 28.5 °C their antioxidant defenses declined, resulting in higher HP content and reduced antioxidant enzyme activity. Muscle showed a dual response. At 27.1 °C it was more resilient, with lower oxidative damage and ∆HPs and stronger antioxidant defense. At 28.5 °C it remained well adapted but exhibited higher ∆HPs and reduced TAC and GR activity with respect to the muscles of oysters collected at 27.1 °C, indicating a decline in antioxidant capacity. COX activity, which remains unchanged in the gills at both elevated temperatures, showed a significant reduction in the muscles of oysters collected from hottest waters, suggesting a shift toward anaerobic metabolism. Overall, P. radiata exhibited high thermal tolerance and physiological plasticity, supporting its persistence in heat-impacted environments. Although the presence of the invasive species P. radiata reflect climate-related ecological pressure, its physiological responses as a climate sentinel indicate that even near optimal temperatures its redox balance is altered, potentially threatening its survival as Mediterranean Sea temperatures continue to rise. These findings are relevant for predicting ecosystem changes under global warming.

Sustainable logistics has become a cornerstone of modern manufacturing, with companies seeking to minimise energy use, CO₂ emissions, and resource inefficiencies throughout the supply chain. This manuscript examines component delivery as a critical aspect of inbound logistics and introduces a digital twin framework to improve its organisation, transparency, and sustainability. The proposed model enables simulation of various delivery scenarios to assess vehicle capacity, fuel consumption, delivery frequency, and warehouse utilisation, providing a comprehensive decision-support tool for balancing economic and environmental objectives.

The digital twin integrates real production data, customer orders, and logistical parameters across various transport vehicles (van, lorry, and lorry with trailer) to generate real-time, data-driven insights (the data are refreshed after each completed shift). The methodology for developing the digital twin uses a previously developed five-stage procedure with integrated algorithms for automatic recognition of the transport vehicle type, automatic detection of the production part type, automatic control of delivered parts, etc. This enables users to perform detailed “what-if” analyses without disrupting actual operations, identifying the most efficient and sustainable delivery configurations. Results from simulated test cases show that larger transport vehicles reduce total fuel consumption by more than 50% and consequently also reduce emissions (Tank-to-Wheel), but increase temporary storage requirements and external warehouse costs. Conversely, smaller vehicles offer greater delivery flexibility but result in higher energy intensity and transport frequency. Validation and verification of the digital twin were conducted using a diverse set of test data designed to reflect typical operational variations and quantity fluctuations, enabling a reliable assessment of the digital twin’s accuracy and robustness for the manuscript.

The findings show that digital twins can be practical enablers of the green and digital transition in manufacturing, linking operational excellence with ecological responsibility.

The Old Brahmaputra River is a vital water resource in Bangladesh, which faces numerous difficulties because of natural variability, human activity, and climate change. This study uses the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) to evaluate the environmental flow requirements (EFR) of the Old Brahmaputra River under historical and future climate change scenarios. Three hydrological techniques are used in the study to assess the EFR for both low-flow and high-flow seasons: the Tennant Method, the Flow Duration Curve (FDC) Method, and the Constant Yield Method (CYM). Using CMIP6 climate models (ACCESS-ESM1-5, BCC-CSM2-MR, and MRI-ESM2-0) under the SSP5-8.5 scenario, future projections were made for the 2030s, 2050s, and 2080s based on historical data from 1994 to 2024. The findings show notable seasonal fluctuations in flow, with the river suffering from severe ecological degradation during the low-flow period, especially in March. The FDC and CYM methods offer more precise, month-by-month estimates, whereas the Tennant Method recommends an EFR of 62.22 cumecs for the low-flow season. The ACCESS-ESM1-5 model predicts considerable increases in monsoon flows in the future, which could result in more frequent and severe flooding. Future projections show growing flow variability. On the other hand, the MRI-ESM2-0 model projects lower future flows, indicating potential water scarcity. In order to meet the challenges brought on by climate change, the study shows the importance of adaptive water resource management strategies, such as preserving minimum flows during the low-flow season. The results highlight the necessity of integrated water resource management to maintain the Old Brahmaputra River's ecological sustainability and sustain the livelihoods of the communities that depend on it.

Water hypoxia, a condition of reduced dissolved oxygen (DO), is one of the most pervasive and increasing stressors linked to climate change, eutrophication, and anthropogenic impacts. Sessile species, such as mussels, are naturally exposed to these fluctuations in oxygen availability since their immobile lifestyle prevents escaping, and this makes them particularly vulnerable to stress. We here aimed to clarify the influence of different periods of exposure to water hypoxia on crucial physiological and biochemical responses of M. galloprovincialis. To this purpose, mussels were exposed to 4 (short) and 10 (prolonged) days of hypoxia (DO at 2.5 mg L-1) and both gills and digestive gland (DG) were used to evaluate the tissue oxidative status in terms of lipid peroxidation and protein oxidation, the expression and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), the expression of the stress-related protein HSP70, together with cell viability, and the cell response to volume changes. We found that, under prolonged hypoxia, lipid peroxidation increased in both DG and gills, while no changes in protein oxidation were observed. In the DG, exposure to both short and prolonged hypoxia is accompanied by the activation of the antioxidant response, with both SOD activity and transcriptional levels markedly upregulated. In the gills only, SOD gene expression increased at 10 days of treatment. In contrast, CAT activity and gene expression, as well as HSP70 expression levels, remained stable across tissues and treatments. Overall, these responses point to a tissue-specific and time-dependent modulation of both oxidative status and antioxidant defenses in mussels challenged by hypoxic stress.

Mediterranean coastal lagoons are increasingly vulnerable to the impacts of climate change, including rising temperatures, altered precipitation regimes, and shifts in hydrological connectivity. These pressures are particularly pronounced in deltaic systems such as the Po River Delta, where the balance between freshwater input, marine intrusion, and anthropogenic activities—especially intensive shellfish farming—plays a critical role in shaping ecosystem structure and function. Phytoplankton communities, as the primary trophic resource for filter-feeding bivalves and sensitive indicators of environmental change, respond rapidly to fluctuations in salinity, light, and nutrient availability. In this study, we investigate the functional traits of phytoplankton—specifically size structure and photosynthetic efficiency (Fv/Fm)—as diagnostic tools to assess ecological responses to aquaculture pressure and climate-driven variability in the Sacca degli Scardovari lagoon, one of the most productive shellfish farming areas in Europe.
Our findings highlight how filter-feeding activity and climate-induced stressors interact to modulate phytoplankton biomass and community composition, with implications for carbon cycling, food web dynamics, and the resilience of transitional coastal ecosystems. By adopting a trait-based approach, this study contributes to a deeper understanding of the ecological functioning of Mediterranean lagoons under multiple stress regimes, offering insights relevant for sustainable aquaculture management and climate adaptation strategies in the Po Delta region.

Ammonia recovery reduces contamination and provides a source of Nitrogen. Ammonia volatilization during solar drying of WWTP sludge ranged from 22% to 74%. A gas-permeable membrane has a short half-life, making it difficult to reuse. Here, we demonstrate the feasibility of ammonium recovery as ammonium sulfate crystals using the heat stored in the dryer, followed by water recovery through condensation. A laboratory-scale solar dryer was designed to use artificial solar light. In one set of experiments, water samples were recovered at their original pH throughout the condensation process. In another setup, an impinger containing sulfuric acid (impinger A) was placed inside the artificial solar dryer. Passing the gas produced during the drying of the sludge to impinger A and then to the condensation setup (a thermostatic bath to condense water vapor). The experiment was replicated, varying the oxygen rate, air recirculation, and artificial alkalization of sludge. Recovered water, ammonia crystals, and acidic residues were analysed for Total Nitrogen (ammonia and inorganic nitrogen), Total Carbon (organic and inorganic carbon), and short-chain carboxylic acids. The loss of ammonium and total nitrogen from fresh sludge during the solar drying prototype measurements was 2.103 g N - NH₄/kg dried sludge and 11.64 g N/kg dried sludge, respectively. Our laboratory setup recovered up to 3.3 g N - NH₄ / kg dried sludge in the form of (NH₄)₂SO₄ by mixing fresh and dried sludge, and 5.5 g N - NH₄ / kg dried sludge after sludge alkalization with ash sludge. The reuse of heat stored in the solar dryer, combined with an air-extraction and condensation system, enhances simultaneous recovery of elements such as ammonia and water. The system still has areas for improvement, such as reducing contamination from the acidic residues and determining an optimal extraction flow to prevent cross-contamination.

The widespread use of psychoactive substances, combined with their incomplete removal in conventional wastewater treatment plants, has led to the increasing environmental presence of biologically active compounds now classified as emerging contaminants. These include pharmaceuticals such as clonazepam, a benzodiazepine prescribed for anxiety and epilepsy, and widely consumed stimulants like caffeine and nicotine. After ingestion, these substances are metabolised and excreted mainly via urine, ultimately entering wastewater systems and aquatic environments, where they persist at ng/L–µg/L concentrations.

Caffeine, nicotine, and clonazepam are among the most commonly detected psychoactive contaminants in surface waters. Although their effects on humans are well understood, their impact on aquatic organisms, especially during early development, remains poorly characterised. While these contaminants often co-occur, understanding the specific role of each compound is crucial for ecological risk assessment.

This preliminary study examined the individual effects of caffeine, nicotine, and clonazepam on the embryonic development of Xenopus laevis, a widely used vertebrate model in ecotoxicology. Embryos were exposed from the 4–8 cell stage using a modified FETAX protocol designed to better reflect environmentally relevant exposure. Concentration ranges similar to those found in surface and wastewater were tested. In addition to standard FETAX endpoints (mortality, body length, and malformations), we measured heart rate, embryo motility, and oxidative stress biomarkers to identify sublethal alterations.

Preliminary results revealed significant developmental abnormalities, including cephalic and abdominal oedema, intestinal defects, bent tail phenotypes, and altered dorsal pigmentation. LC₅₀, EC₅₀, and Teratogenic Index (TI) values confirmed a detectable teratogenic potential for all three compounds. Overall, these findings demonstrate that individual psychoactive contaminants, even at environmentally relevant concentrations, can disrupt early vertebrate development, highlighting their ecological importance and the need for further toxicity assessment.