Applied Geochemistry最新文献

{"title":"Occurrence and provenance of ion-adsorbed rare earth elements mineralization in alumina-rich rocks of the Permian Heshan formation, Western Guangxi, China","authors":"Chunfang Dong ,&nbsp;Zhixuan Han ,&nbsp;Xiaocheng Wei ,&nbsp;Junhong Liu ,&nbsp;Haonan Zhao ,&nbsp;Zhiyan Gu ,&nbsp;Bimin Zhang ,&nbsp;Cheng Xu","doi":"10.1016/j.apgeochem.2025.106498","DOIUrl":"10.1016/j.apgeochem.2025.106498","url":null,"abstract":"<div><div>The enrichment of rare earth elements (REEs) in alumina-rich rocks (ARR) is widely observed. However, REEs in ARR are primarily present in mineral forms, which poses significant challenges to their practical utilization. Recently, the Permian Heshan Formation in Shangsi County, western Guangxi, China, has attracted attention due to the discovery of an unusual occurrence of ion-adsorbed REEs mineralization within ARR. In this study, four ARR samples and an underlying limestone were collected from a single geological profile to investigate the occurrence of REEs through chemical sequential extraction, scanning electron microscopy (SEM), X-ray diffraction (XRD). Furthermore, the provenance of REEs was analyzed based on U–Pb geochronology and chemical compositions in detrital zircons. The results show that REEs content in four ARR ranges from 897 to 2753 ppm, with an average of 1507 ppm, exceeding the industrial grade (1000 ppm) for ion-adsorbed REEs deposits. Notably, the ion-exchangeable phase (F2, average 58.97 %) constitutes the dominant REEs fraction, followed by the residual phase (F7, average 17.98 %), Fe–Mn oxide phase (F5, average 7.01 %), humic acid phase (F4, average 5.58 %), organic-matter phase (F6, average 5.50 %), water soluble phase (F1, average 3.19 %), and carbonate-bound phase (F3, average 0.52 %). Moreover, distinct REEs fractionation patterns are evident across different phases. Light REEs (LREEs) are predominantly adsorbed by clay minerals, whereas heavy REEs (HREEs) primarily retained in the residual phase. The morphology and U–Pb geochronology of detrital zircons provide evidence that the provenance of REEs underwent a significant change from the bottom to the top of the stratigraphic profile. Additionally, mineralogical compositions, chondrite-normalized REE patterns, and zircon geochemical characteristics further support that the variation in REE sources within the profile. Geochemical plots and tectonic discrimination diagrams suggest that REEs in the upper section of the profile primarily originated from the Permian Paleo-Tethys magmatic arc, whereas the lower section predominantly inherited its REEs from the underlying limestone. The introduction of foreign acidic magmatic materials is presumed to have contributed to the formation of the ion-adsorbed REEs enrichment zone within the ARR of the Heshan Formation. The present study contributes to an enhanced and more comprehensive understanding of the mechanism governing REEs enrichment in paleo-weathered horizons.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106498"},"PeriodicalIF":3.1,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weathering promotes the sorption of radiocesium in mafic minerals of river sediments in the Fukushima Prefecture, Japan","authors":"Hiroki Hagiwara ,&nbsp;Yusuke Watanabe ,&nbsp;Hiromi Konishi ,&nbsp;Hironori Funaki ,&nbsp;Kenso Fujiwara ,&nbsp;Kazuki Iijima","doi":"10.1016/j.apgeochem.2025.106490","DOIUrl":"10.1016/j.apgeochem.2025.106490","url":null,"abstract":"<div><div>Radiocesium (¹³⁴Cs and ¹³⁷Cs) was sorbed on minerals and transported to river systems due to the Fukushima Daiichi Nuclear Power Plant accident. Recently, the authors have reported that mafic minerals sorb ¹³⁷Cs equally or more strongly than micaceous minerals in fine sands. We characterized mafic minerals and elucidated their weathering using electron microscopy to determine whether they can sorb ¹³⁷Cs. The surface of hornblende particles is weathered and altered to vermiculite. The surface of micas is less weathered than that of hornblende, indicating the ¹³⁷Cs activity concentrations of highly weathered mafic minerals are higher than those of micas in part of sampling site. The results indicate that the effects of ¹³⁷Cs sorption for hornblende depend on the weathering product at the surface.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106490"},"PeriodicalIF":3.1,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrochemistry of a coastal sedimentary basin: evidence from the Lower Kutai Basin, Indonesia","authors":"Arifin ,&nbsp;Richard G. Taylor ,&nbsp;Mohammad Shamsudduha ,&nbsp;Agus M. Ramdhan ,&nbsp;Irwan Iskandar ,&nbsp;Taat Setiawan ,&nbsp;Munib Ikhwatun Iman ,&nbsp;Riza Arian Noor","doi":"10.1016/j.apgeochem.2025.106496","DOIUrl":"10.1016/j.apgeochem.2025.106496","url":null,"abstract":"<div><div>Groundwater is a vital freshwater resource in coastal regions, where 38 % of the global population currently resides. The hydrochemistry of abstracted groundwater in low-lying deltaic regions can pose a risk to human health, especially where monitoring of groundwater quality is limited. This study investigates new evidence of the hydrochemistry of shallow (depths of &lt;250 m) groundwater in the Lower Kutai Basin (LKB) where Indonesia's new capital, Nusantara, is situated. Shallow groundwater is predominantly (67 out of 73 samples) fresh with a median total dissolved solids of 197 mg/L and hydrochemical facies are dominated by the bicarbonate anion. In this coastal sedimentary basin, high concentrations of iron (median = 5.4 mg/L) and manganese (median = 138 μg/L) that exceed WHO drinking-water guidelines reflect widespread reducing conditions in shallow groundwater, promoted by sluggish flow under low hydraulic gradients (primarily &lt;0.002). Stable isotope ratios (δ¹⁸O, δ²H) indicate that inland fresh groundwater, traced to heavy rainfall, becomes isotopically heavier and more saline toward the coast. Although the hydrochemical conditions favoring arsenic mobilization mirror those of Asian megadeltas, arsenic concentrations in the shallow groundwater of the LKB are generally low (median = 0.5 μg/L).</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106496"},"PeriodicalIF":3.1,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trace element compositions and redox shifts preserved in magnesites, sediments and soils from the Kunwarara magnesite mine","authors":"Carl Swindle ,&nbsp;Paulo Vasconcelos ,&nbsp;Nathan Dalleska ,&nbsp;Emily Cardarelli ,&nbsp;Surjyendu Bhattacharjee ,&nbsp;Zoe Dimarco ,&nbsp;Kenneth A. Farley ,&nbsp;Theodore Present","doi":"10.1016/j.apgeochem.2025.106494","DOIUrl":"10.1016/j.apgeochem.2025.106494","url":null,"abstract":"<div><div>Magnesium carbonates in surficial environments act as CO₂ sinks and can record aspects of the palaeohydrological cycles on Earth and Mars. In natural environments, magnesium carbonates can be intimately intermixed at the micrometer scale with complex assemblages of other non-carbonate minerals. To better determine magnesium carbonate composition in complex samples and minimize contamination from secondary Fe/Mn-oxides/hydroxides, we developed and assessed methods for sample cleaning, selective digestion, and quadrupole inductively coupled plasma mass spectrometry to measure the trace and minor elemental composition. By pre-cleaning and selectively digesting carbonate, we identified previously unrecognized geochemical trends in magnesite ± dolomite nodules and their host fluvial sediments collected along a depth profile at the Kunwarara magnesite mine, Queensland, Australia. In particular, Ce anomalies in magnesite diminishes with depth coincident with decreasing abundances of authigenic Fe/Mn-oxides/hydroxide minerals in the host sediments. These results reveal how the magnesium carbonates capture interactions between the ascending groundwaters and descending surface waters. We further demonstrate the value of magnesium carbonate-specific trace element data with reanalysis of previously published ion microprobe data from Martian meteorite ALH84001, which also shows Ce fractionation. Accurate mineral-specific trace and minor element measurements in Earth and Martian magnesium carbonate samples improve our understanding of the timing and identities of carbonate mineral-forming reactions that occurred on both planets.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"191 ","pages":"Article 106494"},"PeriodicalIF":3.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of sea salt species in snow samples from Svalbard using ICP-QMS and IC techniques","authors":"Azzurra Spagnesi ,&nbsp;Elena Barbaro ,&nbsp;Warren Raymond Lee Cairns ,&nbsp;Matteo Feltracco ,&nbsp;Federico Scoto ,&nbsp;Andrea Gambaro ,&nbsp;Carlo Barbante ,&nbsp;Andrea Spolaor","doi":"10.1016/j.apgeochem.2025.106492","DOIUrl":"10.1016/j.apgeochem.2025.106492","url":null,"abstract":"<div><div>Inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and ion chromatography (IC) paired with either a conductivity detector (IC-CD) or single quadrupole mass spectrometer (IC-MS) are essential techniques in environmental analysis. Previous research has demonstrated robust agreement when applying these methods to Antarctic ice cores and snow samples. However, the high concentrations of sea spray and mineral dust found in Arctic snow samples pose distinct challenges, that might impact the accuracy and precision of measurements, despite the existing efforts to minimise matrix effects. In particular, the higher amount of dust in the Arctic snow/ice samples could present an additional source for insoluble elements typically found in sea spray that is insoluble and thus undetectable by IC, causing a divergency between the results obtained from the two techniques. Therefore, it is crucial to comprehend how these factors influence the efficacy of ICP-QMS and IC techniques in polar research. This study provides a detailed comparison of these methods in quantifying sea salt species – sodium (Na), potassium (K), magnesium (Mg), and bromine (Br) – in surface snow samples collected at Svalbard. By cross-validating IC and ICP-QMS for these tracers, the study assesses each method's accuracy, sensitivity, and precision, providing valuable insights into their optimal application in polar research and climate studies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106492"},"PeriodicalIF":3.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of sediment composition and accumulation on pharmaceutical product spatial distributions at the suburban pond scale (Beulie pond, SNO Observil, France)","authors":"Amélie Humbrecht ,&nbsp;Anaëlle Simonneau ,&nbsp;Thomas Thiebault ,&nbsp;Gauthier Bernier-Turpin ,&nbsp;Claude Le Milbeau ,&nbsp;Veronika Veselská ,&nbsp;Josef Kašlík ,&nbsp;Gildas Ratié ,&nbsp;Lauriane Ledieu ,&nbsp;Lydie Le Forestier","doi":"10.1016/j.apgeochem.2025.106487","DOIUrl":"10.1016/j.apgeochem.2025.106487","url":null,"abstract":"<div><div>Pharmaceutical products (PPs) are found in several compartments of the environment, and are mostly emitted by wastewater treatment plants effluents. Their occurrence in the particulate phase, in opposition with the dissolved one, also promotes their occurrence in retention areas, where particles transported by streams settle. The study focuses on understanding how different constituents of pond sediment are distributed within a suburban pond, revealing patterns or hotspots of PPs accumulation. Results confirmed the heterogeneous spatial distributions of the granulometric fractions, total organic carbon, quantitative palynofacies, crystalline phase distributions and PPs contents. The delta preferentially concentrates total organic carbon (14.5 ± 2.2 %), and particularly terrigenous organic matter and neutral PPs, while the main decantation area accumulates mostly fine particles (58.2 ± 7.7 %), kaolinite, algal organic matter and cationic PPs. The potential role played by OM and kaolinite in PPs adsorption is supported by their respective spatial trends at the pond scale. Further attention should be paid to surface sediments components and PPs sensitivity to seasonal variations, especially in terms of flow, pH and oxygenation of the water-column. This spatial approach allowed to identify preferential accumulation and concentration areas within the pond, where the following extensive characterization of interface sediments highlighted the factor likely to influence PPs trapping within the pond.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106487"},"PeriodicalIF":3.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment color as a predictor of the subsurface redox conditions at large scale","authors":"Hyojin Kim ,&nbsp;Ingelise Møller ,&nbsp;Lærke Thorling ,&nbsp;Birgitte Hansen","doi":"10.1016/j.apgeochem.2025.106493","DOIUrl":"10.1016/j.apgeochem.2025.106493","url":null,"abstract":"<div><div>The redox conditions of the subsurface are critical for predicting nitrate transport and fate in groundwater. Groundwater chemistry of redox-sensitive parameters can be used to infer subsurface redox conditions; however, it typically provides only point-scale information and requires significant time and effort to acquire large datasets. In soil science, soil/sediment colors have been used to qualitatively infer redox status in different soil horizons. In this study, we quantitatively assessed the potential of sediment color as a proxy for subsurface redox conditions at a national scale in Denmark. We did so by comparing sediment color classifications with groundwater redox conditions from approximately 4000 groundwater screens across the country. The sediment color dataset included seven base colors i.e., red, yellow, black, blue, green (olive), gray, and brown, encompassing a total of 89 variations, accounting for nuances (e.g., yellowish, grayish) and lightness (light vs dark). Our results revealed that, overall, qualitative redox interpretations based on sediment color aligned well with the oxic groundwater fraction. Gray and brown groups were the predominant colors, and within each group, the oxic water fraction increased with oxic-associated nuances (e.g., yellowish gray) and lighter shades (e.g., light yellowish gray) compared to their respective base color (i.e., gray). Most brown colors and gray shades with oxic (e.g., yellowish gray) and brownish nuances (e.g., brownish gray) showed oxic water fractions that decreased exponentially with increasing depth, suggesting hydrological controls on the redox conditions. Based on these findings, sediment color data from more than 27,000 boreholes across the country were quantitatively translated into oxic probability, enabling more precise delineation of the redox interface. Since sediment color data can be collected rapidly and at large scales, it provides a reliable and cost-effective means of assessing subsurface redox conditions. Therefore, sediment colors data have great potential to enhance large-scale modelling of redox-sensitive contaminant transport and fate.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106493"},"PeriodicalIF":3.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling of Fe and N cycles by nitrate-reducing Fe(II)-oxidizing microorganisms in the tidal sediments of an extreme acidic river (Río Tinto, Spain)","authors":"Martina Bottaro ,&nbsp;Sergey Abramov ,&nbsp;Ricardo Amils ,&nbsp;Adrian Martinez-Bonilla ,&nbsp;Laurel ThomasArrigo ,&nbsp;Daniel Straub ,&nbsp;Muammar Mansor ,&nbsp;Sara Kleindienst ,&nbsp;Andreas Kappler","doi":"10.1016/j.apgeochem.2025.106488","DOIUrl":"10.1016/j.apgeochem.2025.106488","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Río Tinto (Huelva, Spain) is an acid rock drainage-affected fluvial estuarine system where Fe(II)-oxidizing microorganisms were shown to be active both in the water column and in the top sediment layer, contributing to Fe mineral accumulation (up to 30 % of dry sediment weight) in the estuarian sediment. However, it is still unknown if the Fe(II)-oxidizing microorganisms thriving in the upper sediment layer are also capable of using nitrate present in the river (0.05–0.5 mM) as electron acceptor. We performed sediment incubations amended with either lactate, acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; or NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; to evaluate Fe-cycling processes and, specifically, if nitrate reduction coupled to Fe(II) oxidation (NRFeOx) can occur in the sediment under anoxic conditions. Geochemical data showed that in the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt; (from 1.5 to 0 mM), Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; (from 1.5 to 0 mM) and pH (from 6.0 to 5.4) decreased, while the poorly crystalline Fe(III) mineral pool increased by 6.9 % during 114 days of incubation. In the acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup, nitrate reduction rates (0.31 mM NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/day) were 10 times faster compared to the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup (0.03 mM NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;/day). pH and poorly crystalline Fe(II) mineral content increased due to Fe(III) reduction after amendment with only lactate (0.26 ± 0.03 mM Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;/day) but also after amendment with acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt; (0.16 ± 0.02 mM Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;/day) suggesting that acetate-stimulated Fe(III) reduction superimposed Fe(II) oxidation coupled to nitrate reduction. Sequencing data showed that upon addition of nitrate, members of the genus &lt;em&gt;Rhodanobacter&lt;/em&gt; increased by ⁓10 % in relative DNA-based 16S rRNA gene abundances in both acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;- and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setups. However, the &lt;em&gt;Rhodanobacter&lt;/em&gt; RNA-based 16S rRNA relative gene abundance was higher in the acetate-/NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended setup (11.15 ± 2.24 %) than in the NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;-/Fe&lt;sup&gt;2+&lt;/sup&gt;&lt;sub&gt;aq&lt;/sub&gt;-amended one (5.40 ± 0.31 %). Combining geochemical and sequencing data obtained from anoxic sediment incubations, we conclude that NRFeOx processes, potentially catalyzed by the genus &lt;em&gt;Rhodanobacter&lt;/em&gt;, can play a role in Fe cycling in this extreme acid rock drainage affected river, under low organic carbon (OC) conditions. At higher OC levels, NRFeOx microorganisms seem to become more active but their net effects on Fe(II) oxidation can be diminished due to the simultaneous activi","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106488"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144580584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probabilistic human health risk assessment due to potential toxic elements in gold mining-affected areas of Antioquia, Colombia","authors":"Julián E. López ,&nbsp;Samantha Jiménes-Oyola ,&nbsp;Juan F. Marín ,&nbsp;Juan F. Saldarriaga","doi":"10.1016/j.apgeochem.2025.106491","DOIUrl":"10.1016/j.apgeochem.2025.106491","url":null,"abstract":"<div><div>The purpose of this study was to determine the probabilistic human health risk (both non-carcinogenic and carcinogenic) associated with the concentration of potentially toxic elements (PTEs) in soil samples from gold mining-impacted areas in three municipalities of Antioquia, Colombia. Soil samples were collected from the study area, and the concentrations of As, Cd, Pb, and Cr were analyzed. Human exposure to these PTEs was assessed for both adults and children through incidental soil ingestion and dermal contact during outdoor activities. To evaluate the potential adverse health effects, PTEs concentrations were analyzed using the Hazard Index (HI) and Total Cancer Risk (TCR). The minimum and maximum concentrations of As, Cd, Pb, and Cr were 1.7–892 mg kg⁻¹, 0.1–65.2 mg kg⁻¹, 13.0–2345 mg kg⁻¹, and 5.4–301 mg kg⁻¹, respectively. The probabilistic risk analysis indicated HQ and CR values above the safe exposure threshold, suggesting that, if exposure conditions are maintained, residents exposed to contaminated soils may face risks to their health. The results indicate that in Puerto Berrío and Buriticá, a significant proportion of children are exposed to non-carcinogenic risk levels far exceeding safe limits, with Puerto Berrío being the most critical area, where exposure levels surpass the safety threshold by up to 40 times. Overall, the findings of this study provide new scientific evidence that can support data-driven decision-making for the development of regulations and improved environmental management strategies.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106491"},"PeriodicalIF":3.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical migration-induced mineral reactions at the bentonite-concrete interface in multi-barrier systems","authors":"Ajeong Kim ,&nbsp;Dongwoo Lee ,&nbsp;Jang-Soon Kwon ,&nbsp;Heewon Jung","doi":"10.1016/j.apgeochem.2025.106489","DOIUrl":"10.1016/j.apgeochem.2025.106489","url":null,"abstract":"<div><div>This study investigates the effect of electrochemical migration on the geochemical stability of multi-barrier nuclear waste repositories. We used a multicomponent reactive transport modeling approach to conduct two simulations: one considering only Fickian diffusion (FD) and another incorporating both Fickian diffusion and electrochemical migration using the Nernst-Planck equation (NP). The model domain consisted of bentonite, concrete, and granite barriers. The NP simulation results revealed Ca²⁺ fluxes moving against their concentration gradients across the bentonite-concrete interface (BCI), driven by Coulombic interactions. This uphill diffusion of Ca²⁺ is coupled with the downhill diffusion of SO₄²⁻, resulting in the concurrent migration of both ions from bentonite to concrete. This process triggers slow gypsum dissolution and precipitation near the BCI, even though local equilibrium with respect to gypsum was reached. These unexpected mineral reactions across the BCI persist even after gypsum is completely depleted in the bentonite near the interfaces, as long as the pore connection near the BCI is maintained. Our findings highlight the significance of electrochemical effects for the long-term stability of multi-barrier systems in nuclear waste repositories.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"190 ","pages":"Article 106489"},"PeriodicalIF":3.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}