High Metal Concentrations Research Articles

Содержание химических элементов в костистых лучах плавников Acipenser gueldenstaedtii (Brandt, 1833)

One of the reasons for the decline in the number of sturgeon fish species is the complex ecological situation in the Volga-Caspian basin. Changes in the hydrochemical composition of the Volga-Caspian basin water are accompanied by critical disturbances in the microelement balance of the fish organism and lead to irreversible pathological consequences in the populations of valuable fish species. In order to preserve the population and monitor the condition of sturgeon fish species, a detailed study of the microelement composition of their organs and tissues is necessary. The concentration of chemical elements in the bony rays of the fins of Russian sturgeon Acipenser gueldenstaedtii (Brandt, 1833) of different sexes and age composition (3-10 years) was determined using the atomic absorption method according to GOST 30178-96. Iron, copper, manganese, zinc, nickel, cobalt, chromium, lead, cadmium were determined in each sample. It is noted that all nine studied metals are able to accumulate in sturgeon bone rays to one degree or another. Iron in sturgeon bone rays was present in large quantities relative to other chemical elements. Lead occupied the second place in terms of content in the rays, followed by zinc and cobalt in descending order, and cadmium was found in the lowest concentrations. Copper, zinc, and manganese were shown to have higher metal concentrations in the rays of males, and nickel, chromium, cobalt, lead, and cadmium in the rays of female Russian sturgeon. The differences revealed between the average iron concentrations in the studied organs of females and males of all studied age groups are statistically insignificant. It was noted that with increasing age, weight, and length, the metal content in the bone rays of both males and females increased.

Research progress on acid mine drainage treatment based on CiteSpace analysis

Acid mine drainage has always been of global concern, primarily due to its low pH, high concentration of heavy metals and toxic substances, and serious impact on the surrounding environment and ecology of mines. However, the research progress and hotspots in this field of acid mine drainage processing are still unclear. To better understand the research hotspots and trends of acid mine drainage processing from 2004 to 2023, we used CiteSpace bibliometric software to visually analyze 1142 English-language research articles and reviews from the Web of Science core database. Results indicated that this field has received increas-ing attention from researchers worldwide, especially since 2017. The USA and China stand out as major contributors, yet their international collaboration doesn't match South Africa robust partnerships. Strengthening cooperation with other nations should be a priority for both the USA and China. The University of Quebec and University of South Africa were the most production institution. Vhahangwele Masindi from South Africa was the most active author. The top two core journals in this field were Science of the Total Environment and Water Re-search. Additionally, through keyword co-occurrence, clustering, and burst analysis, it is evi-dent that research on heavy metal mechanisms and resource recovery will be the future re-search hotspots in this field of acid mine drainage. This study provides researchers with an opportunity to understand the hotspots and trends in acid mine drainage research from a bibliometric perspective, and serves as a reference for future studies.

Exploration and impact of Metlaoui-Gafsa phosphate rock amendment: the role of Serratia plymuthica BMA1 in phosphate solubilization, heavy metal rhizoaccumulation, and enhanced nutrition in Vicia faba L.

The geochemical analysis of Gafsa rock phosphate (GRP) revealed relatively high concentrations of essential plant minerals and trace heavy metals (HMs). Environmental contamination factors indicated moderate to very strong HM contamination due to GRP soil amendment. The potential use of the Serratia plymuthica BMA1 strain, which is known for its ability to solubilize GRP, to enhance mineral nutrition in Vicia faba L. and its role in HM rhizoaccumulation from GRP were explored. Pot experiments revealed that bacterization with S. plymuthica BMA1 in V. faba grown in sand supplemented with GRP as the sole source of phosphorus significantly increased the potassium concentration by 64% in roots and 40% in shoots, iron by 20% in roots and 10% in shoots, and manganese by 27% in roots and 20% in shoots compared to that in V. faba not inoculated with S. plymuthica BMA1. The total dry biomass of V. faba increased by approximately 85%, while the accumulation of cadmium (Cd), copper (Cu), zinc (Zn), and lead (Pb) in the roots increased by 114%, 30%, 37%, and 44%, respectively. However, in the shoots, they increased by 35%, 10%, 85%, and 25%, respectively, for Cd, Cu, Zn, and Pb compared to those in the non-inoculated V. faba. The evaluation of the HM translocation factor, bioaccumulation factor, and bioconcentration factor with GRP highlighted the key role of S. plymuthica BMA1 in preventing the mobility of toxic HMs from reaching the aerial parts of plants. These findings suggest that S. plymuthica BMA1 has the potential to enhance mineral nutrition in V. faba and facilitate the rhizoaccumulation of toxic HMs, which has implications for plant cultivation and human consumption.

Effects of the reopening of the Grand-Bassam inlet on the seasonal dynamics of some trace metals in the superficial sediments from the area II of the Ébrié system

The objective of this work was to assess the impacts of the permanent reopening of the Grand-Bassam inlet on the seasonal dynamics of thirteen trace metals in the superficial sediments of the area II from the Ébrié system. In its implementation, the sediment samples were collected over a year (from May 2023 to April 2024). The concentrations of these trace metals were obtained by inductively coupled plasma mass spectrometry (ICP MS) according to ISO 17294-2 after dissolution according to NF X31-147. The results showed a significant input of these metals by meteorological inputs during the rainy, cold, and flood seasons, except for Cr, whose presence in these substrates was mainly related to the strong marine intrusion during the hot season. The modification of the geochemical and physical characteristics due to the reopening of this pass significantly influenced the presence of these trace metals in these substrates during the study period. A reduction in the use of inputs containing high concentrations of trace metals and the efficient treatment of anthropogenic discharges with high metal content in the watershed of this ecosystem should be considered to support the depollution initiated with the reopening of this inlet.

Morphological and physiological responses of Momordica charantia to heavy metals and nutrient toxicity in contaminated water

This study investigates the impact of industrial wastewater from leather, household, and marble sources on the growth, physiological traits, and biochemical responses of Momordica charantia (bitter melon). Industrial activities often lead to the release of contaminated effluents, which can significantly affect plant health and agricultural productivity. Water analysis revealed that leather effluent contained high concentrations of heavy metals, including cadmium (2.67 mg/L), lead (1.95 mg/L), and nickel (1.02 mg/L), all of which exceeded the recommended safety limits for irrigation. Seed germination was significantly reduced, with only 45% germination in seeds irrigated with leather effluent, compared to 90% in the control group. Similarly, in plants treated with leather wastewater, shoot length, and root length were reduced by 38% and 42%. Chlorophyll content showed a marked decline, with chlorophyll “a” reduced by 25% and chlorophyll “b” by 30% in wastewater-treated plants, indicating impaired photosynthetic activity. Antioxidant enzyme activity, including catalase and superoxide dismutase, increased by up to 40%, reflecting a stress response to heavy metal toxicity. These findings highlight that industrial wastewater severely disrupts plant metabolic processes, leading to stunted growth and physiological stress. To safeguard crop productivity and food security, stringent wastewater treatment protocols must be implemented to mitigate environmental contamination. Future research should focus on developing advanced remediation techniques and sustainable wastewater management practices to reduce heavy metal toxicity and enhance soil health.

Metal concentrations in native and transplanted species in the Eastern Ionian Sea (Greece).

Metal concentrations (Cu, Cr, Ni, Zn, Fe, Mn, Cd, and Pb) in marine indicator species were assessed for the study of metal pollution in the Eastern Ionian Sea during the cold period of the year (December 2018 to February 2019). Limpets and sea urchins were collected from natural populations at seven coastal stations while mussels were transplanted at three near-shore stations in the study area. Mixed mesozooplankton samples were selected from a twelve-station offshore network. Additionally, fish, shrimp, and shortfin squid samples were collected by trawling. For the first time, metal concentrations in marine animals were measured in an extended variety of organisms in the area. Higher metal concentrations in limpets, sea urchins, and mussels were observed in the wider area of the two ports located at the sampling area's eastern and southern geographical borders. Levels in zooplankton also followed the same spatial variation. In general, metal concentrations in the investigated organisms were within the same range as those in other non-impacted Mediterranean areas. Accordingly, metal levels in the flesh of the fish, shrimps, and the mantle of shortfin squids did not reveal any risk for human consumption. Metal levels from the present study are proposed as a reference state for the area, while future deviations should be evaluated taking into account potential changes in the natural and anthropogenic pressures on the specific coastal marine ecosystem.

Urinary Metal Levels, Cognitive Test Performance, and Dementia in the Multi-Ethnic Study of Atherosclerosis.

Metals are established neurotoxicants, but evidence of their association with cognitive performance at low chronic exposure levels is limited. To investigate the association of urinary metal levels, individually and as a mixture, with cognitive tests and dementia diagnosis, including effect modification by apolipoprotein ε4 allele (APOE4). The multicenter prospective cohort Multi-Ethnic Study of Atherosclerosis (MESA) was started from July 2000 to August 2002, with follow-up through 2018. A total of 6303 MESA participants were included. Data analysis was performed from October 12, 2023, to June 13, 2024. Urine samples were collected at baseline (2000-2002), and arsenic, cadmium, cobalt, copper, lead, manganese, tungsten, uranium, and zinc levels were measured in 2020-2022. Digit Symbol Coding (DSC) (n = 3819) (possible score range, 0-133), Cognitive Abilities Screening Instrument (CASI) (n = 3918) (possible score range, 0-100), and Digit Span (DS) (n = 4176) (possible score range, 0-30) cognitive tests were administered in 2010-2012; higher scores of each test indicate increasing levels of positive response. A total of 6303 participants were followed up for dementia diagnosis through 2018. The median age at baseline was 60 (IQR, 53-70) years, and 3303 participants (52.4%) were female. The median cognitive scores were 51 (IQR, 38-64) for DSC, 90 (IQR, 84-95) for CASI, and 15 (IQR, 12-18) for DS. There were 559 cases of dementia through the follow-up period. Inverse associations with DSC were identified: mean differences in z scores per IQR increase in metal levels were -0.03 (95% CI, -0.07 to 0.00) for arsenic, -0.05 (95% CI, -0.09 to -0.004) for cobalt, -0.05 (95% CI, -0.07 to -0.02) for copper, -0.04 (95% CI, -0.08 to -0.001) for uranium, and -0.03 (95% CI, -0.06 to -0.01) for zinc. Among 1058 APOE4 carriers, manganese was also inversely associated with DSC. The joint mean difference of DSC comparing percentile 95th with the 25th of the 9-metal mixture was -0.30 (95% CI, -0.47 to -0.14) for APOE4 carriers and -0.10 (95% CI, -0.19 to -0.01) for noncarriers. Arsenic, cadmium, cobalt, copper, tungsten, uranium, and zinc were individually associated with dementia, with hazard ratios per IQR of metal ranging from 1.15 (95% CI, 1.03-1.29) for tungsten to 1.46 (95% CI, 1.06-2.02) for uranium. The joint hazard ratio of dementia comparing percentiles 95th with the 25th of the 9-metal mixture was 1.71 (95% CI, 1.24-3.89), with no significant difference by APOE4 status. In this study, participants with higher concentrations of metals in their urine, compared with those with lower concentrations, had worse performance on cognitive tests and greater likelihood of developing dementia. The findings of this multicenter multiethnic cohort study might inform screening and potential interventions for prevention of dementia based on individuals' metal exposure levels and genetic profiles.

Innovative dual-benefit recycling and sustainable management of municipal solid waste incineration fly ash via ultra-high performance concrete

Millions of tons of municipal solid waste incineration fly ash are generated worldwide each year. Currently, landfilling is the primary disposal method, consuming vast land resources and posing significant risks of soil and groundwater contamination due to the high concentration of hazardous heavy metals. Thus, this study investigated the potential of recycling hazardous municipal solid waste incineration fly ash into non-hazardous ultra-high performance concrete for sustainable development. The mechanisms of heavy metal solidification and binding were examined through Density Functional Theory calculations and microscale experiments. Heavy metals are solidified through the adsorption and binding effects of calcium silicate hydrate and the encapsulation effect of the compact accumulation within the concrete structure. The pore structure of the concrete and the chemical reactions between the fly ash and cement were analyzed to validate the heavy metal solidification mechanism. After solidification, the leaching concentrations of heavy metals from the concrete were two orders of magnitude lower than the limit specified by the Toxicity Characteristic Leaching Procedure. The autogenous shrinking of UHPC with MSWIFA was reduced by about 50 %, and the compressive strength of the concrete decreased. The incorporation of MSWIFA led to approximately a 20 % reduction in energy consumption and carbon emissions. The concrete with MSWIFA exhibited better overall performance. This study presents an innovative and effective approach for recycling municipal solid waste incineration fly ash into non-hazardous concrete, contributing to sustainable hazardous waste management and reducing environmental pollution caused by heavy metals.

Pollution affects even oceanic marine protected areas in Southwestern Atlantic.

Reefs are facing a global decline with sewage pollution emerging as a significant and poorly understood threat. Inadequate wastewater management and disorderly urbanization contributes to water pollution globally. Tropical Southwestern Atlantic comprises a set of oceanic Marine Protected Areas (MPAs) including the Fernando de Noronha Archipelago in Brazil, which has experienced significant population growth without expanding the sewage infrastructure. We mapped and quantified marine pollution in these MPAs, characterizing pollution sources and evaluating their effects on benthic and fish communities in 13 reef sites. We quantified nutrients, metals and metalloid, microplastics, fecal sterols, and Polycyclic Aromatic Hydrocarbons (PAHs) in both water and sediment samples. We also used isotopic tracing on macroalgae to identify the origin of organic matter and characterized benthic and fish communities, and algae biomass at each site. Pollution was more pronounced in the multiple-use area but also affected no-take areas. Effluents from wastewater treatment plants did not meet legislative standards, and reefs in the multiple-use area were enriched in orthophosphate and ammonia compared to those in the no-take area. Nitrogen isotopes in macroalgae revealed sewage-derived nitrogen throughout the multiple-use area. Nutrient enriched sites exhibited higher abundances of fast-growing and opportunistic green macroalgae, and higher biomass of brown macroalgae. The port area, within the multiple-use area, showed high PAHs, coprostanol and metal(loid) concentrations, suggesting untreated sewage and nautical chemical pollution. Microplastics were widespread in sediment and water samples. We documented the pervasive impacts of marine pollution on reef habitats even within marine protected areas in oceanic regions, demonstrating that local pollution control, sewage management and regulating procedures in port areas are critical to protect marine ecosystems. Comparisons with previous studies suggest marine pollution has substantially increased in the Archipelago in the last ten years. This is the first comprehensive assessment of marine pollution in an oceanic environment in Southwestern Atlantic, showing these isolated environments are not immune to pollution impacts.

Exploring the Plant Growth-Promotion Properties of Rhizospheric and Endophytic Bacteria Associated with Robinia pseudoacacia L. in Serpentine Soil.

Serpentine soils are characterized as a unique environment with low nutrient availability and high heavy metal concentrations, often hostile to many plant species. Even though these unfavorable conditions hinder the growth of various plants, particular vegetation with different adaptive mechanisms thrives undisturbed. One of the main contributors to serpentine adaptation represents serpentine bacteria with plant growth-promoting properties that assemble delicate interactions with serpentine plants. Robinia pseudoacacia L. is an invasive but adaptive species with phytoremediation potential and demonstrates extraordinary success in this environment. To explore more in-depth the role of plant growth-promoting serpentine bacteria, we isolated them and tested their various plant growth-promoting traits both from the rhizosphere and roots of R. pseudoacacia. Based on the demonstrated plant growth-promoting traits such as siderophore production, phosphate solubilization, nitrogen fixation, indole-3-acetic acid production, and ACC deaminase production, we sequenced overall 25 isolates, 14 from the rhizosphere and 11 from the roots. Although more efficient in exhibiting plant growthpromoting traits, rhizospheric bacteria showed a low rate of diversity in comparison to endophytic bacteria. The majority of the isolates from the rhizosphere belong to Pseudomonas, while isolates from the roots exhibited higher diversity with genera Pseudomonas, Bacillus, Staphylococcus, Lysinibacillus and Brevibacterium/Peribacillus/Bacillus. The capacity of the described bacteria to produce siderophores, solubilize phosphate, and fix nitrogen highlights their central role in enhancing nutrient availability and facilitating R. pseudoacacia adaptation to serpentine soils. The findings highlight the potential significance of serpentine bacteria, particularly Pseudomonas, in contributing to the resilience and growth of R. pseudoacacia in serpentine environments.

Spatial distributions, potential sources, and ecological risks of heavy metals in stream sediments in Zambia

The ecological risk assessment and source identification of heavy metals (HMs) are significant for resource utilization and food security. This study aims to assess the spatial distributions, potential sources, and ecological risks of HMs in stream sediments in Zambia. Using 735 samples collected from stream sediments across the country and methods such as inductively coupled plasma mass spectrometry (ICP-MS), atomic fluorescence spectrometry (AFS), and X-ray fluorescence spectrometry (XRFS), this study determined the concentrations of the seven HMs, i.e., arsenic (As), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn). The spatial distributions of these HMs were determined using a Geographic Information System (GIS), and their ecological risks were accessed based on the analytical results of their potential sources. Additionally, this study explored the relationships between mining activities and regions with high heavy metal (HM) concentrations based on the statistical analysis of the HM concentrations and geology of the study area. The results indicate the stream sediments in Zambia exhibit average As, Cr, Cu, Hg, Ni, Pb, and Zn concentrations of 1.49 × 10−6, 19.34 × 10−6, 12.12 × 10−6, 12.70 × 10−9, 7.13 × 10−6, 12.52 × 10−6, and 16.30 × 10−6, respectively. The analytical results of the geoaccumulation index (Igeo) and potential ecological risk index (PERI) reveal the presence of relatively high As and Cu concentrations, especially in Copperbelt and North-Western provinces and areas surrounding Lusaka—the capital of Zambia. The HM contamination in stream sediments in Zambia is primarily caused by Cu and gold (Au) mining. This study exemplifies how to determine potential sources and ecological risks of HMs in stream sediments, holding important implications for nation-scale environmental contamination prevention and land utilization planning.

Assessing Environmental Risks of Local Contamination of Garden Urban Soils with Heavy Metals Using Ecotoxicological Tests

Heavy metal soil contamination in urban areas poses a significant environmental hazard, particularly in regions with historical or ongoing industrial activities. These areas are often polluted with metals such as Pb, Cu, Cd, and Zn, which can be absorbed by plants and pose risks to both ecosystems and human health. This study investigates soil contamination in urban gardens in Wroclaw, Poland, where elevated levels of trace elements were detected. Standard soil analyses, including macroelement content, granulometry, and trace element concentrations, were performed alongside an ecotoxicological evaluation using an Ostracodtoxkit test. The test evaluates the impact of contaminants on organism growth. An uncontaminated urban garden soil served as a reference. This study revealed that Zn, Cu, Pb, and Cd concentrations in soils exceeded limits permitted by Polish regulations in several soil samples. Despite the high concentrations of total metals, the bioavailable forms of these metals (measured by extraction of 1 M NH4NO3 extraction) were significantly lower, highlighting that the total metal content may not fully reflect the environmental risk. Pb was identified as the primary contributor to growth inhibition of test organisms, showing a particularly strong correlation with ecotoxicity. These findings underscore the importance of using ecotoxicological tests to evaluate soil contamination risks.

The Genomic Signature and Transcriptional Response of Metal Tolerance in Brown Trout Inhabiting Metal-Polluted Rivers.

Industrial pollution is a major driver of ecosystem degradation, but it can also act as a driver of contemporary evolution. As a result of intense mining activity during the Industrial Revolution, several rivers across the southwest of England are polluted with high concentrations of metals. Despite the documented negative impacts of ongoing metal pollution, brown trout (Salmo trutta L.) survive and thrive in many of these metal-impacted rivers. We used population genomics, transcriptomics, and metal burdens to investigate the genomic and transcriptomic signatures of potential metal tolerance. RADseq analysis of six populations (originating from three metal-impacted and three control rivers) revealed strong genetic substructuring between impacted and control populations. We identified selection signatures at 122 loci, including genes related to metal homeostasis and oxidative stress. Trout sampled from metal-impacted rivers exhibited significantly higher tissue concentrations of cadmium, copper, nickel and zinc, which remained elevated after 11 days in metal-free water. After depuration, we used RNAseq to quantify gene expression differences between metal-impacted and control trout, identifying 2042 differentially expressed genes (DEGs) in the gill, and 311 DEGs in the liver. Transcriptomic signatures in the gill were enriched for genes involved in ion transport processes, metal homeostasis, oxidative stress, hypoxia, and response to xenobiotics. Our findings reveal shared genomic and transcriptomic pathways involved in detoxification, oxidative stress responses and ion regulation. Overall, our results demonstrate the diverse effects of metal pollution in shaping both neutral and adaptive genetic variation, whilst also highlighting the potential role of constitutive gene expression in promoting metal tolerance.

Linking the transcriptome to physiology: response of the proteome of Cupriavidus metallidurans to changing metal availability.

Cupriavidus metallidurans CH34 is a metal-resistant bacterium. Its metal homeostasis is based on a flow equilibrium of metal ion uptake and efflux reactions, which adapts to changing metal concentrations within an hour. At high metal concentrations, upregulation of the genes for metal efflux systems occurs within minutes. Here, we investigate the changes in the bacterial proteome accompanying these genetic and physiological events after 1.5 cell duplications, which took 3 h. To that end, C. metallidurans CH34 and its plasmid-free derivative, AE104, either were challenged with a toxic metal mix or were cultivated under metal-starvation conditions, followed by bottom-up proteomics. When metal-shocked or -starved cells were compared with their respective controls, 3540 proteins changed in abundance, with 76% appearing in one, but not the other, condition; the remaining 24% were up- or downregulated. Metal-shocked C. metallidurans strains had adjusted their proteomes to combat metal stress. The most prominent polypeptides were the products of the plasmid-encoded metal-resistance determinants in strain CH34, particularly the CzcCBA transenvelope efflux system. Moreover, the influence of antisense transcripts on the proteome was also revealed. In one specific example, the impact of an asRNA on the abundance of gene products could be demonstrated and this yielded new insights into the function of the transmembrane efflux complex ZniCBA under conditions of metal starvation.

Evaluating radionuclide mobility in groundwater recharge areas of fractured natural barrier systems using multiple isotopes and microbial indicators

The distribution of uranium (U) concentrations, which reached up to 322 µg/L, was found to correlate with the pattern of fractures within the natural barrier system (NBS). Analysis of the vertical distribution of dissolved oxygen (DO), dissolved organic carbon (DOC), tritium (3H), microbial communities, and H2O and SO42– isotopes revealed insights into oxic water infiltration within the heterogeneous fractured system. Their distribution showed that the average infiltration depth at the KURT site is 200 m, while in external areas with a high frequency of fractures, oxic conditions extended down to 495 m. The SO42– isotopes suggested the potential for microbial sulfate reduction to play a role in regulating radionuclide mobility in the deep geological system. At approximately 500 m, genera capable of thriving under harsh conditions of low DO and high heavy metal concentrations, such as Novosphingobium, Comamonadaceae_uc, and Desulfuromonas_g2, were identified. These findings indicate hydrogeological variability and microbial adaptation within the deep NBS, highlighting the importance of understanding the deep geological environment for evaluating microbiome performance in regulating toxic radionuclides within repository systems. Overall, this study emphasizes the pivotal role of age tracers, stable isotopes, and microbiome in enhancing the assessment of the long-term stability of fractured granite barriers.

Galamsey Saga Case Study; The Forensics Overlooked, International Intervention To Save The Ghanaian Sustainable Environment.

Using googles scholar search engine, the phrase “Galamsey activities in Ghana” gave average results of about 3,160 articles from the 19th century through to present. This tells us the scholarly work done on the galamsey and its menace. The breath and length of galamsey inherent attention, through research works. But it is ironic to say that because as of September 2024 the entire nation is crying for a state of emergency and seeking intervention to stop galamsey operation, but the government is silent. This case study research focuses on the key research areas concerning galamsey such as analytical chemical research, social and political to argue the work done using the narrative approach. From the case study it can be concluded that the scholars have done their part to showcase the dangers associated with galamsey such as high concentration of heavy metals in the waters bodies that is namely Mercury (Hg), Cyanide (CN), Cadmium (Cd), Arsenic (As), Lead Pb), Manganese (Mn), Copper (Cu), Zinc (Zn) and Iron (Fe) and degrading of soil, the land and health with air contamination concerns. Recent development from health services at Komfo Anokye Teaching Hospital in the Ashanti region recorded deformities in babies born to parents living in galamsey environments which is due to heavy metal poisoning during pregnancy. Ghana Water Company which is the main water treating company in the country has failed to treat the polluted water due to over polluted water and breakdown of the water treating instruments. This is clear as treated tap waters from Ghana Water Company Limited (GWCL) have the same brown color (turbidity) as the polluted rivers. It finally concluded galamsey is still in operation due to political and legal imbalance from the major political parties in Ghana namely National Democratic Congress Party (NDC) and the New Patriotic Party (NPP) including landowners or chiefs. This case study underscores this galamsey case to the entire nations in Africa and the world to investigate this matter, suggest routes and aid to sustain the Ghanaian sustainable environment.

Hierarchically-porous resin for the adsorption of organic matter in raffinate produced by solvent extraction from the vanadium industry

Solvent extraction wastewater contains high concentrations of organic pollutants and metal ions, making it difficult to treat. This paper presents a method of using hierarchically-porous adsorption resin to recover organics from raffinate and regenerate the resin, addressing secondary pollution in extraction processes. The chosen resin, WS6108, removes over 95 % of organics from raffinate, with high metal ion concentrations enhancing its adsorption efficiency. The article conducted an optimization experiment and mechanism study on WS6108 resin for adsorbing organic matter in vanadium raffinate (OIVR), followed by desorption and recycling tests. Results showed WS6108 resin achieved a 96.7 % adsorption efficiency at a solid–liquid ratio of 24 g/L after optimization. The chosen methanol desorbent achieves over 99 % desorption efficiency for the WS6108 cycle under specific conditions. The resin’s performance remains stable for up to 45 cycles. Adsorption isotherms and kinetic experiments indicate that OIVR adsorption by WS6108 resin is endothermic, non-spontaneous and entropy increasing. Moreover, the adsorption kinetics of OIVR by WS6108 resin followed a pseudo-second-order model, based on the activation energy, liquid film diffusion was considered the main rate-controlling step. A column experiment was conducted to verify that WS6108 resin can be used in real vanadium raffinate to remove organics. Density functional theory (DFT) revealed that strong hydrogen bonding, π-π stacking and excellent adsorption diffusion behavior drive OIVR adsorption. This study aims to increase the use of adsorption to treat oily wastewater generated by solvent extraction.

Geoelectrical resistivity and geochemistry monitoring of landfill leachates due to the seasonal variations and the implications on groundwater systems and public health

Understanding the seasonal variations in the landfill leachate plumes (LLPs) properties and complex connections between concentrations of leachate variability, and its environment is essential for environmental and public health management. This study explores the combined electrical resistivity (ER) data and physiochemical water analysis (PWA) coupled with the excavations to monitor the landfill physiochemical properties (LPPs) due to seasonal variations and their implications on environmental vital organs and public health. The variations in ER and LLP distributions across the overburdened top layer due to seasonal changes were examined. The low ER contrasts were encountered within the ranges of 1.5 Ωm – 19.0 Ωm which was mapped as LLP accumulated zones within the landfill, while high ER values varied between 15 Ωm – 260 Ωm off-the landfill extending beyond 15 m. The results of the PWA indicate high concentrations of heavy metals (HMs) such as iron (Fe), lead (Pb), zinc (Zn), and cadmium (Cd) decreasing with wet seasons and increasing with dry seasons. The overall high concentration of HMs in the LLPs was indeed varied between 9.81 ± 2.15–19.07 ± 3.68, while the electrical conductivity (EC) significantly increased from 17.99 ± 1.92 mg/L to 24.87 ± 3.31 mg/L towards the wet season. The increment and decrement encountered in the LPPs are due to seasonal variation and dilution. The order of decrement in the HMs in the LLPs treads as follows EC > Fe > Zn > Pb > Cd in values, respectively. The near-surface EC aligned well with the ER results and boundaries of the waste disposal site, which was verified by the soil excavations. In addition, the ER method was extended beyond the landfill for adequate monitoring, identifying the subsurface layers, conductive shallow zones mapped as the zones of LLP accumulation, resistive deep and shallow zones mapped as the consolidated lateritic topsoil and crystalline basement rocks in some cases, and a dipping conductive lineament zones identified as fracture zones just before the crystalline basement. In conclusion, the ER technique reveals the vertical and horizontal extents of the LLP escapade, the PWA expressed the concentrations of HMs in the LLPs, heightening the implications on the environmental and human health. Finally, the combined techniques deployed for monitoring the physiochemical properties of LLPs due to seasonal variation and the impacts on the integrity of groundwater quality systems and public health inform sustainable waste management practices, which contributes significantly to the protection of groundwater resources and the development of effective strategies to safeguard groundwater systems and public health for present and future generations.

The Origin of the Matter Matters: The Influence of Terrestrial Inputs on Coastal Benthic Microeukaryote Communities Revealed by eDNA

ABSTRACTEstuaries are a key component of the land‐sea continuum, and their microbial diversity depends on the connection with terrestrial ecosystems. This work aimed to demonstrate that the terrestrial matter carried by rivers influences the structuration of microeukaryote communities of superficial (0–3 cm) sediments collected at the interface between the land and marine coastal areas. To demonstrate this hypothesis, we have chosen the main island of New Caledonia as a study site, a French overseas territory located in the South West Pacific. Using amplicon sequencing of the 18S‐V4 rDNA extracted from sediments, we analyzed microeukaryote community composition in relation to numerous environmental parameters. Samples were collected in five bays influenced by riverine inputs and corresponding to distinct geological features of the watersheds, as revealed by high variations in metal concentrations released from specific minerals in the sediment. Particularly, the influence of ultramafic soils was highlighted by higher nickel concentration (correlated to Co, Cr, Mn, and Fe). Diatoms were the dominant taxonomic group, especially the classes of Bacillariophyceae and Mediophyceae. Then Apicomplexa, Ciliophora, Dinoflagellata, and Cercozoa followed. The metallic composition of the sediment explained 18.46% of the community spatial variability. The selection of ASVs based on their contribution to beta diversity and their correlation with metallic concentrations enabled us to identify spatial patterns. This information could lead to identifying microeukaryote bioindicators of terrestrial influences, particularly of ultramafic origin. We hypothesized that the association between microeukaryotes and metallic compositions is linked to selection processes, given the resistance of some microeukaryotes to some high metallic concentrations. In vitro experiments are needed to confirm this hypothesis. Our results emphasized the role of terrestrial inputs in shaping estuarine diversity and the need to consider the entire land–sea continuum for studying these ecosystems.

Tracing fluid signature and metal mobility in complex orogens: insights from Pb-Zn mineralization in the Pyrenean Axial Zone

AbstractOrogenic processes encompass a complex interplay of deformation and metamorphic events, which can impact the formation of ore deposits to various degrees. However, distinguishing fluid signatures from orogenic versus post-orogenic events presents a significant challenge due to the scarcity of robust geochemical indicators that remain unaffected during multiple post-mineral reworking events. This study carefully examines the properties and chemistry of primary and secondary fluid inclusions (FIs), identifying distinct signatures of two fluid populations linked to different styles of Pb-Zn mineralization in the Pyrenean Axial Zone (PAZ) of Southern-France/Northern-Iberia: These included late-Carboniferous stratabound epigenetic Pb-Zn deposits and Mesozoic crosscutting Pb-Zn(-Ge) vein systems. Population (I) is identified in primary and secondary FIs in a few crosscutting Pb-Zn veins and constitutes a minor component in stratabound epigenetic bodies. It exhibits Na-dominated low to intermediate salinity (< 20 wt% NaCl eq.), intermediate temperatures (200–350 °C), abundant CO2-rich FIs and shows low homogeneous Cl/Br molar ratios. These characteristics are consistent with a metamorphic origin of the fluids, associated with Late-Variscan metamorphism. Population (II) is commonly observed in the crosscutting vein systems where it occurs as primary and pseudosecondary FIs, as well as in stratabound epigenetic bodies where it represents the main fluid component of secondary FIs. Population (II) is Ca-dominated with intermediate to high salinity (15–35 wt% NaCl eq.), relatively low temperature (< 200 °C), and shows high Cl/Br molar ratios with significant variations. This last characteristic is typical of mixing of at least two fluids, one with a probable low Cl/Br molar ratio at shallow crustal levels and another with high Cl/Br molar ratio at deeper levels. Characteristics of population (II) are consistent with a fluid of basinal origin that interacted with the basement while circulating in the Pyrenees during the Mesozoic, although a Pyrenean-Alpine age cannot be excluded. Locally, in sphalerite-hosted secondary FIs that form trails in the crosscutting veins, we find evidence of high Ge concentrations (up to few 1000s ppm), which correlate with anomalous Pb and Tl concentrations. Very high metal concentrations (up to 1–2 wt% Pb, Zn), which are inversely proportional to Cl/Br molar ratios, are found in FIs mainly within veins hosted in deep-seated high-grade metamorphic rocks. Based on a compilation of fluid data from the literature, a first-order correlation can be deduced between the metamorphic grade of the rocks hosting the mineralization and the Pb and Zn content in the FIs. Early stratabound orebodies are considered likely sources of metal for the development of the late crosscutting vein mineralization. This study demonstrates the significance and complexity of orogen-scale fluid circulation and supports the importance of pre-existing metal enrichment in the crust, especially in high-grade metamorphic rocks as a prerequisite for the formation of Pb-Zn veins in complex multi-stage orogens.