Pub Date : 2026-01-28DOI: 10.1016/j.apgeochem.2026.106712
Timothy C.C. Lui , Anirudh Prabhu , Anna Bidgood , Shaunna M. Morrison , Jef Caers
In this paper we introduce GeoChemNet as a novel tool for visualizing and analyzing high-dimensional geochemical datasets. Unlike traditional approaches such as principal component analysis and pairplots, GeoChemNet uses a non-linear methodology that does not require predefined number of elements, allowing it to reveal highly multidimensional anomalies that are not elucidated using other methods. We demonstrate its advantages using an artificial dataset and compare its performance to conventional techniques. We then apply the tool to two case studies from the same region. The first illustrates how GeoChemNet can work synergistically with clustering algorithms to uncover structure within lithological units. The second demonstrates its utility as a standalone tool for reducing the search space in mineral exploration of sediment-hosted copper deposits. Ultimately, GeoChemNet's interactive, geospatial visualizations enhance communication between geoscientists and data scientists and uncover geological insights from geochemical datasets.
{"title":"GeoChemNet: An interactive tool for visualizing and interpreting outliers in geochemical data using networks","authors":"Timothy C.C. Lui , Anirudh Prabhu , Anna Bidgood , Shaunna M. Morrison , Jef Caers","doi":"10.1016/j.apgeochem.2026.106712","DOIUrl":"10.1016/j.apgeochem.2026.106712","url":null,"abstract":"<div><div>In this paper we introduce <em>GeoChemNet</em> as a novel tool for visualizing and analyzing high-dimensional geochemical datasets. Unlike traditional approaches such as principal component analysis and pairplots, <em>GeoChemNet</em> uses a non-linear methodology that does not require predefined number of elements, allowing it to reveal highly multidimensional anomalies that are not elucidated using other methods. We demonstrate its advantages using an artificial dataset and compare its performance to conventional techniques. We then apply the tool to two case studies from the same region. The first illustrates how <em>GeoChemNet</em> can work synergistically with clustering algorithms to uncover structure within lithological units. The second demonstrates its utility as a standalone tool for reducing the search space in mineral exploration of sediment-hosted copper deposits. Ultimately, <em>GeoChemNet</em>'s interactive, geospatial visualizations enhance communication between geoscientists and data scientists and uncover geological insights from geochemical datasets.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"199 ","pages":"Article 106712"},"PeriodicalIF":3.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071114","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}
Pub Date : 2026-01-21DOI: 10.1016/j.apgeochem.2026.106711
Yong Xiao , Liwei Wang , Jie Wang , Xu Guo , Zhihong Zhang , Jiahua Wei , Zhen Zhao , Shaokang Yang , Huijuan Chen , Nuan Yang , Guangbin Zhu
Groundwater is of paramount significance for sustaining the socio-economic development and ecological health of arid endorheic intermountain basins. However, its availability is severely limited by hydrochemical composition, which remains inadequately quantified. This study takes the Chaka Basin on the Tibetan Plateau as an example to elucidate the spatial patterns, driving forces, and their quantitative contributions of groundwater geochemistry in such arid endorheic basins. Results indicate that groundwater is generally alkaline with substantial spatial variability in salinity. Near the mountain pass, groundwater remains fresh (TDS <1 g/L), retaining favorable hydrochemical characteristics inherited from mountain-sourced recharge. Salinity increases progressively along the groundwater flow path, with a notable contrast between phreatic and confined aquifers in the middle-lower reaches. Phreatic groundwater shows high TDS (>10 g/L near the terminal lake), while confined groundwater remains relatively fresh under the same settings, largely due to evaporation. Hydrogeochemical compositions are predominantly contributed by water–rock interactions, including evaporite dissolution (40.18 %), silicate weathering (16.31 %), and fluoride mineral dissolution/ion exchange (13.08 %). Human activities, such as agricultural practices (16.31 %) and domestic sewage discharge (13.41 %), also exert considerable contributions. A conceptual model was developed to elucidate the spatial patterns and quantitative formation mechanisms of groundwater chemistry. These findings provide a systematic framework for understanding the hydrogeochemical evolution and availability of groundwater quality in arid endorheic basins worldwide.
{"title":"Groundwater hydrogeochemical evolution and driving forces in a typical arid closed intermountain basin on Tibetan Plateau: a quantitative framework","authors":"Yong Xiao , Liwei Wang , Jie Wang , Xu Guo , Zhihong Zhang , Jiahua Wei , Zhen Zhao , Shaokang Yang , Huijuan Chen , Nuan Yang , Guangbin Zhu","doi":"10.1016/j.apgeochem.2026.106711","DOIUrl":"10.1016/j.apgeochem.2026.106711","url":null,"abstract":"<div><div>Groundwater is of paramount significance for sustaining the socio-economic development and ecological health of arid endorheic intermountain basins. However, its availability is severely limited by hydrochemical composition, which remains inadequately quantified. This study takes the Chaka Basin on the Tibetan Plateau as an example to elucidate the spatial patterns, driving forces, and their quantitative contributions of groundwater geochemistry in such arid endorheic basins. Results indicate that groundwater is generally alkaline with substantial spatial variability in salinity. Near the mountain pass, groundwater remains fresh (TDS <1 g/L), retaining favorable hydrochemical characteristics inherited from mountain-sourced recharge. Salinity increases progressively along the groundwater flow path, with a notable contrast between phreatic and confined aquifers in the middle-lower reaches. Phreatic groundwater shows high TDS (>10 g/L near the terminal lake), while confined groundwater remains relatively fresh under the same settings, largely due to evaporation. Hydrogeochemical compositions are predominantly contributed by water–rock interactions, including evaporite dissolution (40.18 %), silicate weathering (16.31 %), and fluoride mineral dissolution/ion exchange (13.08 %). Human activities, such as agricultural practices (16.31 %) and domestic sewage discharge (13.41 %), also exert considerable contributions. A conceptual model was developed to elucidate the spatial patterns and quantitative formation mechanisms of groundwater chemistry. These findings provide a systematic framework for understanding the hydrogeochemical evolution and availability of groundwater quality in arid endorheic basins worldwide.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106711"},"PeriodicalIF":3.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024121","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}
Pub Date : 2026-01-20DOI: 10.1016/j.apgeochem.2026.106702
Wuyan Wang , Qingguang Li , Weiqi Lu , Shangyi Gu
Anthropogenic nitrogen (N) loading significantly influences nitrous oxide (N2O) emissions from freshwater ecosystems, but the effects of watershed N management on these emissions remain poorly quantified. This study investigated N2O dynamics in two adjacent, seasonally stratified reservoirs, Hongfeng (HF) and Baihua (BH), in the Wujiang Basin, China, which share similar climatic and limnological conditions but experience different levels of anthropogenic N input. The downstream BH Reservoir, located closer to urban areas, received higher N loads, resulting in significantly higher nitrate (NO3−) concentrations compared to the upstream HF Reservoir. Correspondingly, BH exhibited remarkably higher surface N2O concentration and an estimated N2O emission flux (20.0 μmol m2 d−1) approximately double that of HF (9.6 μmol m2 d−1). Historical data revealed that N2O emissions peaked during periods of severe pollution (2003–2008) and declined following the implementation of watershed pollution abatement, demonstrating that effective nutrient control not only improves water quality but also materially mitigates N2O emissions. The seasonal co-variation of N2O with NH4+ suggests that NH4+ availability directly controls the short-term production rates, which accords the generally-accepted viewpoint that nitrification is the main pathway of N2O production in reservoirs. On the other hand, NO3− influences the long-term baseline emission potential via phytoplankton-mediated recycling. These findings highlight that managing anthropogenic N inputs is crucial and effective for reducing N2O emissions from deep reservoirs.
人为氮(N)负荷显著影响淡水生态系统的氧化亚氮（N2O）排放，但流域氮管理对这些排放的影响仍然缺乏量化。研究了吴江盆地两个相邻的季节性分层水库洪峰（HF）和白花（BH）的N2O动态，这两个水库具有相似的气候和湖泊条件，但经历了不同的人为N输入水平。BH水库下游靠近城市地区，受氮负荷较大，导致硝酸盐（NO3−）浓度明显高于上游HF水库。相应地，BH的表面N2O浓度显著高于HF (9.6 μmol m2 d - 1)， N2O发射通量（20.0 μmol m2 d - 1）约为HF的两倍。历史数据显示，N2O排放量在严重污染时期（2003-2008年）达到峰值，在实施流域污染治理后下降，表明有效的养分控制不仅可以改善水质，而且可以实质性地减少N2O排放。N2O与NH4+的季节共变表明，NH4+的有效性直接控制了短期产速率，这与普遍认为的硝化作用是水库N2O产的主要途径的观点一致。另一方面，NO3−通过浮游植物介导的再循环影响长期基线排放潜力。这些发现强调，管理人为N输入对于减少深层水库的N2O排放至关重要且有效。
{"title":"N2O emissions from two adjacent, seasonally stratified reservoirs in the Wujiang Basin: Influences of N addition and N managements","authors":"Wuyan Wang , Qingguang Li , Weiqi Lu , Shangyi Gu","doi":"10.1016/j.apgeochem.2026.106702","DOIUrl":"10.1016/j.apgeochem.2026.106702","url":null,"abstract":"<div><div>Anthropogenic nitrogen (N) loading significantly influences nitrous oxide (N<sub>2</sub>O) emissions from freshwater ecosystems, but the effects of watershed N management on these emissions remain poorly quantified. This study investigated N<sub>2</sub>O dynamics in two adjacent, seasonally stratified reservoirs, Hongfeng (HF) and Baihua (BH), in the Wujiang Basin, China, which share similar climatic and limnological conditions but experience different levels of anthropogenic N input. The downstream BH Reservoir, located closer to urban areas, received higher N loads, resulting in significantly higher nitrate (NO<sub>3</sub><sup>−</sup>) concentrations compared to the upstream HF Reservoir. Correspondingly, BH exhibited remarkably higher surface N<sub>2</sub>O concentration and an estimated N<sub>2</sub>O emission flux (20.0 μmol m<sup>2</sup> d<sup>−1</sup>) approximately double that of HF (9.6 μmol m<sup>2</sup> d<sup>−1</sup>). Historical data revealed that N<sub>2</sub>O emissions peaked during periods of severe pollution (2003–2008) and declined following the implementation of watershed pollution abatement, demonstrating that effective nutrient control not only improves water quality but also materially mitigates N<sub>2</sub>O emissions. The seasonal co-variation of N<sub>2</sub>O with NH<sub>4</sub><sup>+</sup> suggests that NH<sub>4</sub><sup>+</sup> availability directly controls the short-term production rates, which accords the generally-accepted viewpoint that nitrification is the main pathway of N<sub>2</sub>O production in reservoirs. On the other hand, NO<sub>3</sub><sup>−</sup> influences the long-term baseline emission potential via phytoplankton-mediated recycling. These findings highlight that managing anthropogenic N inputs is crucial and effective for reducing N<sub>2</sub>O emissions from deep reservoirs.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106702"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024122","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}
Pub Date : 2026-01-20DOI: 10.1016/j.apgeochem.2026.106706
Samuel Bolduc , Daniele L. Pinti , Marie Larocque , Olfa Swaissi
Groundwater ages cannot be considered precise metrics for directly evaluating the sustainability of water resources. However, determining the age distribution enhances understanding of the entire hydrogeological system and, indirectly, contributes to the assessment of sustainability. The objective of this research was to evaluate how a combination of age tracers can contribute to estimating groundwater age distribution in large and complex aquifer systems. The system consists of fractured Grenvillian-age (≥ 1 Ga) aquifers, locally covered by granular postglacial Holocene aquifers in valley bottoms of the mountainous and hilly Laurentides region of southern Québec Province (Eastern Canada). The age tracers used in this study, 14C, 3H/3He, and U–Th/4He were measured on groundwater samples collected from 32 municipal wells and one piezometer, from five watersheds. As expected, mixed idealized ages were obtained. The 3H/3He ages varied from modern to 64 years. The 14C-corrected ages generally ranged from “modern” to 6500 years old. The U–Th/4He-computed ages were close to the 14C ages but were strongly dependent on local aquifer conditions, primarily on U and Th contents and porosity. Three “activity indexes” – A4He, A3H, and A14C representing groundwater aging recorded a common temporal evolution of groundwater, with increasing ages from the southernmost, more populated areas to the less populated areas in the northern portion of the study area. Lumped parameter models applied to 3H–14C and to radiogenic 4He–14C showed that the aquifers contain a mixture of “modern” and “pre-industrial” water (200–14,000 yrs), and possibly Late Pleistocene water (10–30 ka) in some confined areas. This research advances the understanding of regional hydrogeology, providing insights into how North America's glacial history has influenced the mixing of groundwater volumes of different ages, thereby affecting groundwater sustainability differently in a complex aquifer system.
{"title":"Groundwater age distribution in granular and fractured aquifers of the Laurentides region, Eastern Canada, to evaluate the resource sustainability","authors":"Samuel Bolduc , Daniele L. Pinti , Marie Larocque , Olfa Swaissi","doi":"10.1016/j.apgeochem.2026.106706","DOIUrl":"10.1016/j.apgeochem.2026.106706","url":null,"abstract":"<div><div>Groundwater ages cannot be considered precise metrics for directly evaluating the sustainability of water resources. However, determining the age distribution enhances understanding of the entire hydrogeological system and, indirectly, contributes to the assessment of sustainability. The objective of this research was to evaluate how a combination of age tracers can contribute to estimating groundwater age distribution in large and complex aquifer systems. The system consists of fractured Grenvillian-age (≥ 1 Ga) aquifers, locally covered by granular postglacial Holocene aquifers in valley bottoms of the mountainous and hilly Laurentides region of southern Québec Province (Eastern Canada). The age tracers used in this study, <sup>14</sup>C, <sup>3</sup>H/<sup>3</sup>He, and U–Th/<sup>4</sup>He were measured on groundwater samples collected from 32 municipal wells and one piezometer, from five watersheds. As expected, mixed idealized ages were obtained. The <sup>3</sup>H/<sup>3</sup>He ages varied from modern to 64 years. The <sup>14</sup>C-corrected ages generally ranged from “modern” to 6500 years old. The U–Th/<sup>4</sup>He-computed ages were close to the <sup>14</sup>C ages but were strongly dependent on local aquifer conditions, primarily on U and Th contents and porosity. Three “activity indexes” – A<sup>4</sup>He, A<sup>3</sup>H, and A<sup>14</sup>C representing groundwater aging recorded a common temporal evolution of groundwater, with increasing ages from the southernmost, more populated areas to the less populated areas in the northern portion of the study area. Lumped parameter models applied to <sup>3</sup>H–<sup>14</sup>C and to radiogenic <sup>4</sup>He–<sup>14</sup>C showed that the aquifers contain a mixture of “modern” and “pre-industrial” water (200–14,000 yrs), and possibly Late Pleistocene water (10–30 ka) in some confined areas. This research advances the understanding of regional hydrogeology, providing insights into how North America's glacial history has influenced the mixing of groundwater volumes of different ages, thereby affecting groundwater sustainability differently in a complex aquifer system.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"199 ","pages":"Article 106706"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071080","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}
Pub Date : 2026-01-20DOI: 10.1016/j.apgeochem.2026.106685
Lukas Rieder , Mathilde Hagens , Reinaldy Poetra , Alix Vidal , Tullia Calogiuri , Anna Neubeck , Abhijeet Singh , Thomas Corbett , Harun Niron , Sara Vicca , Siegfried E. Vlaeminck , Iris Janssens , Tim Verdonck , Ivan Janssens , Xuming Li , Jens S. Hammes , Jens Hartmann
Total Alkalinity (TA) is widely used as a proxy for captured CO2 in enhanced weathering (EW) applications. However, organic anions can also contribute to TA. To improve carbon accounting in EW, which is often simplified to that TA equals carbonate alkalinity, their contribution should be taken into account.
In this study, we tested how dissolved organic carbon (DOC) contributes to non-carbonate alkalinity (ANC) using microcosm experiments with artificial organo-mineral mixtures. We used different combinations of rock powder with straw, microbes and earthworm additions, under ambient air conditions. The microcosms were flow-through columns placed in a climate chamber at 25 °C, which were irrigated with groundwater at rates between 1200 and 3600 mm/yr. The concentrations of several low-molecular-weight organic acids (oxalate, citrate, acetate, gluconate) were quantified to assess which conjugate base anions impact the measured TA.
Results revealed a ratio of 3.5 mol DOC per ANC equivalent. In the overall experiment the median contribution of ANC to TA was around 5.5 %. A positive correlation between DOC and charge-balance error suggests that some organic acid anions remained deprotonated during TA titration. Acetate anions found in DOC-rich water samples further support a substantial contribution of organic anions to TA. To investigate the relevance of ANC for natural EW systems, we also quantified ANC contributions in natural waters and leachates from soil EW experiment mesocosms. Because DOC levels were lower, ANC contributions were smaller, ranging from a median of 4.1 % in soil mesocosm leachates down to 0.9 % in Elbe estuary water samples. This ANC contribution, despite seeming small, is relevant for carbon accounting in terrestrial EW practices, where TA is often assumed to be solely carbonate alkalinity.
{"title":"Contribution of dissolved organic carbon to total alkalinity in Enhanced Weathering experiments","authors":"Lukas Rieder , Mathilde Hagens , Reinaldy Poetra , Alix Vidal , Tullia Calogiuri , Anna Neubeck , Abhijeet Singh , Thomas Corbett , Harun Niron , Sara Vicca , Siegfried E. Vlaeminck , Iris Janssens , Tim Verdonck , Ivan Janssens , Xuming Li , Jens S. Hammes , Jens Hartmann","doi":"10.1016/j.apgeochem.2026.106685","DOIUrl":"10.1016/j.apgeochem.2026.106685","url":null,"abstract":"<div><div>Total Alkalinity (TA) is widely used as a proxy for captured CO<sub>2</sub> in enhanced weathering (EW) applications. However, organic anions can also contribute to TA. To improve carbon accounting in EW, which is often simplified to that TA equals carbonate alkalinity, their contribution should be taken into account.</div><div>In this study, we tested how dissolved organic carbon (DOC) contributes to non-carbonate alkalinity (A<sub>NC</sub>) using microcosm experiments with artificial organo-mineral mixtures. We used different combinations of rock powder with straw, microbes and earthworm additions, under ambient air conditions. The microcosms were flow-through columns placed in a climate chamber at 25 °C, which were irrigated with groundwater at rates between 1200 and 3600 mm/yr. The concentrations of several low-molecular-weight organic acids (oxalate, citrate, acetate, gluconate) were quantified to assess which conjugate base anions impact the measured TA.</div><div>Results revealed a ratio of 3.5 mol DOC per A<sub>NC</sub> equivalent. In the overall experiment the median contribution of A<sub>NC</sub> to TA was around 5.5 %. A positive correlation between DOC and charge-balance error suggests that some organic acid anions remained deprotonated during TA titration. Acetate anions found in DOC-rich water samples further support a substantial contribution of organic anions to TA. To investigate the relevance of A<sub>NC</sub> for natural EW systems, we also quantified A<sub>NC</sub> contributions in natural waters and leachates from soil EW experiment mesocosms. Because DOC levels were lower, A<sub>NC</sub> contributions were smaller, ranging from a median of 4.1 % in soil mesocosm leachates down to 0.9 % in Elbe estuary water samples. This A<sub>NC</sub> contribution, despite seeming small, is relevant for carbon accounting in terrestrial EW practices, where TA is often assumed to be solely carbonate alkalinity.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106685"},"PeriodicalIF":3.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024054","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}
Pub Date : 2026-01-19DOI: 10.1016/j.apgeochem.2026.106699
Rashmi Ranjan Mandal, Deep Raj
Phytoremediation using Eichhornia crassipes was assessed as a sustainable strategy for the removal and stabilization of arsenic (As) and mercury (Hg) from contaminated aquatic systems, followed by the conversion of harvested biomass into biochar to enhance long-term metal immobilization. The study assessed plant performance under two different contamination levels (1 and 5 mg L−1) to understand concentration-dependent responses. At the lower concentration, E. crassipes achieved high removal efficiencies, arrive at 93 % As and 87 % Hg reduction within 30 days. However, the removal decreased significantly at 5 mg L−1, with efficiencies dropping to 76 % for As and 52 % for Hg, indicating physiological limitations and reduced uptake capacity under higher metal stress. Morphological and spectroscopic study revealed significant structural alterations in plant tissues and showed the accumulation of As and Hg within cellular sections, validating the plant's role as an effective accumulator species. To ensure safe post-harvest handling and prevent secondary contamination, the metal-enriched biomass was subjected to pyrolysis. The resulting biochar showed strong retention of both metals, attributed to its carbonaceous structure and enhanced binding sites formed during thermal transformation. This stable biochar demonstrated clear potential for long-term immobilization and reduced metal mobility. Overall, the integrated process combining phytoremediation with biomass valorization offers an eco-friendly, cost-effective, and circular approach for mitigating toxic metal contamination in water bodies. The outcomes highlight the double benefit of pollutant removal and the production of a value-added material, improving the applicability of E. crassipes in sustainable environmental management.
{"title":"Sustainable removal of arsenic and mercury via integrated phytoremediation and biomass valorization of Eichhornia crassipes","authors":"Rashmi Ranjan Mandal, Deep Raj","doi":"10.1016/j.apgeochem.2026.106699","DOIUrl":"10.1016/j.apgeochem.2026.106699","url":null,"abstract":"<div><div>Phytoremediation using <em>Eichhornia crassipes</em> was assessed as a sustainable strategy for the removal and stabilization of arsenic (As) and mercury (Hg) from contaminated aquatic systems, followed by the conversion of harvested biomass into biochar to enhance long-term metal immobilization. The study assessed plant performance under two different contamination levels (1 and 5 mg L<sup>−1</sup>) to understand concentration-dependent responses. At the lower concentration, <em>E. crassipes</em> achieved high removal efficiencies, arrive at 93 % As and 87 % Hg reduction within 30 days. However, the removal decreased significantly at 5 mg L<sup>−1</sup>, with efficiencies dropping to 76 % for As and 52 % for Hg, indicating physiological limitations and reduced uptake capacity under higher metal stress. Morphological and spectroscopic study revealed significant structural alterations in plant tissues and showed the accumulation of As and Hg within cellular sections, validating the plant's role as an effective accumulator species. To ensure safe post-harvest handling and prevent secondary contamination, the metal-enriched biomass was subjected to pyrolysis. The resulting biochar showed strong retention of both metals, attributed to its carbonaceous structure and enhanced binding sites formed during thermal transformation. This stable biochar demonstrated clear potential for long-term immobilization and reduced metal mobility. Overall, the integrated process combining phytoremediation with biomass valorization offers an eco-friendly, cost-effective, and circular approach for mitigating toxic metal contamination in water bodies. The outcomes highlight the double benefit of pollutant removal and the production of a value-added material, improving the applicability of <em>E. crassipes</em> in sustainable environmental management.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106699"},"PeriodicalIF":3.4,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024053","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}
Pub Date : 2026-01-17DOI: 10.1016/j.apgeochem.2026.106707
Jean-Philippe Nicot, Lucy T. Ko, Roxana Darvari, Brent A. Elliott
We describe dissolved lithium content of water produced from the Haynesville Shale, a low-permeability, gas-producing formation of Jurassic age overlying the lithium-rich and stratigraphically close Smackover Formation. The 57 water samples and 5 rock samples were analyzed for major and minor elements and for stable water isotopes, and Li and Sr isotopes (selected samples). The samples show an average of 71.7 mg/L Li (16–125 mg/L range) for an average TDS of 126.7 g/L (55–206 g/L range). They also show that the Haynesville and Smackover dissolved lithium have distinct diagenetic pathways with a large gap in δ7Li values (3.27 ‰, n = 7 and 10.20 ‰, n = 4, respectively). However, δ7Li of Haynesville produced water and rock (−4.03 ‰, n = 5) are consistent with fractionation of lithium partitioned into clay minerals relative to the resident water. The Haynesville Shale strontium isotope 87Sr/86Sr ratio (0.70830, n = 5) is higher than that of the time-period sea (0.7070), and consistent with a clastic 87Sr increase in a closed system, but lower than that of the published Arkansas carbonate-rich Upper Smackover values (0.70895, n = 72), which denotes a stronger clastic influence there. Water isotopes confirm that the samples represent formation water and have been little impacted by hydraulic fracturing or water condensation during sampling. However, low water production combined with marginal Li concentrations does not make the Haynesville Shale a primary target for lithium production.
{"title":"Dissolved lithium content and aqueous geochemistry of the Haynesville Shale of East Texas and Northwest Louisiana","authors":"Jean-Philippe Nicot, Lucy T. Ko, Roxana Darvari, Brent A. Elliott","doi":"10.1016/j.apgeochem.2026.106707","DOIUrl":"10.1016/j.apgeochem.2026.106707","url":null,"abstract":"<div><div>We describe dissolved lithium content of water produced from the Haynesville Shale, a low-permeability, gas-producing formation of Jurassic age overlying the lithium-rich and stratigraphically close Smackover Formation. The 57 water samples and 5 rock samples were analyzed for major and minor elements and for stable water isotopes, and Li and Sr isotopes (selected samples). The samples show an average of 71.7 mg/L Li (16–125 mg/L range) for an average TDS of 126.7 g/L (55–206 g/L range). They also show that the Haynesville and Smackover dissolved lithium have distinct diagenetic pathways with a large gap in δ<sup>7</sup>Li values (3.27 ‰, n = 7 and 10.20 ‰, n = 4, respectively). However, δ<sup>7</sup>Li of Haynesville produced water and rock (−4.03 ‰, n = 5) are consistent with fractionation of lithium partitioned into clay minerals relative to the resident water. The Haynesville Shale strontium isotope <sup>87</sup>Sr/<sup>86</sup>Sr ratio (0.70830, n = 5) is higher than that of the time-period sea (0.7070), and consistent with a clastic <sup>87</sup>Sr increase in a closed system, but lower than that of the published Arkansas carbonate-rich Upper Smackover values (0.70895, n = 72), which denotes a stronger clastic influence there. Water isotopes confirm that the samples represent formation water and have been little impacted by hydraulic fracturing or water condensation during sampling. However, low water production combined with marginal Li concentrations does not make the Haynesville Shale a primary target for lithium production.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106707"},"PeriodicalIF":3.4,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024124","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}
Pub Date : 2026-01-17DOI: 10.1016/j.apgeochem.2026.106705
Leire Coloma, Iratxe Población, Julene Aramendia, Fernando Alberquilla, Jennifer Huidobro, Gorka Arana, Juan Manuel Madariaga
The study of meteorites is important for planetary sciences because, among other things, it can provide information about the geochemical composition of their celestial body of origin. Often, subsample preparation is required to investigate the internal regions of these meteorites. However, during this process, the use of various tools and reagents can introduce contaminants, which are not always fully removable. As a result, exogenous substances may be detected during subsequent geochemical characterization analyses. To prevent the problems that may arise from this issue, this study analyzes multiple Martian meteorites with the aim of identifying contaminants introduced during sample preparation processes. Raman spectroscopy, one of the techniques used for extraterrestrial sample analysis, was employed to detect these residues. Establishing a robust subsample preparation protocol is essential not only for future sample return missions, where the ability to prepare uncontaminated subsamples upon arrival on Earth will be critical for accurate scientific investigations, but also for the handling of any type of meteorite.
{"title":"Analysing the sample preparation process in meteorites and its impact on the pretreatment of returned samples to Earth","authors":"Leire Coloma, Iratxe Población, Julene Aramendia, Fernando Alberquilla, Jennifer Huidobro, Gorka Arana, Juan Manuel Madariaga","doi":"10.1016/j.apgeochem.2026.106705","DOIUrl":"10.1016/j.apgeochem.2026.106705","url":null,"abstract":"<div><div>The study of meteorites is important for planetary sciences because, among other things, it can provide information about the geochemical composition of their celestial body of origin. Often, subsample preparation is required to investigate the internal regions of these meteorites. However, during this process, the use of various tools and reagents can introduce contaminants, which are not always fully removable. As a result, exogenous substances may be detected during subsequent geochemical characterization analyses. To prevent the problems that may arise from this issue, this study analyzes multiple Martian meteorites with the aim of identifying contaminants introduced during sample preparation processes. Raman spectroscopy, one of the techniques used for extraterrestrial sample analysis, was employed to detect these residues. Establishing a robust subsample preparation protocol is essential not only for future sample return missions, where the ability to prepare uncontaminated subsamples upon arrival on Earth will be critical for accurate scientific investigations, but also for the handling of any type of meteorite.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106705"},"PeriodicalIF":3.4,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974369","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}
Pub Date : 2026-01-16DOI: 10.1016/j.apgeochem.2026.106679
Wei Cao , Xianglan Kong , Jingdong Mao , Jianfang Hu , Yong Ran
Rising global temperature is exerting a notable effect on the photosynthetic process of marine algae, which in turn may affect the structure and distribution of marine primary producers on a global scale. Sea surface temperature exerts a multifaceted influence on the growth, composition and structure of dinoflagellate, as well as on inorganic carbon fixation. This paper investigates the effect of temperature change on the growth of one dinoflagellate specie Scrippsiella trochoidea, and examines the variations in the organic carbon structure of its cell wall. This study is pioneering in its exploration of the impact of temperature on the structural organisation of organic matter in the dinoflagellate, with a particular focus on methylene carbon. The results indicate that Scrippsiella trochoidea exhibits a propensity to synthesise elevated levels of aliphatic compounds and proteins, particularly long-chain aliphatic biopolymers, at elevated incubation temperature. Moverover, a highly positive correlation is identified between the incubation temperature and the methylene carbon structure in the alkyl carbon structure. Such compositional and structural changes can have a significant impact on the potential yield of oil and gas through the process of algal pyrolysis.
{"title":"Compositions and hydrocarbon generation potentials of Scrippsiella trochoidea under increasing temperature","authors":"Wei Cao , Xianglan Kong , Jingdong Mao , Jianfang Hu , Yong Ran","doi":"10.1016/j.apgeochem.2026.106679","DOIUrl":"10.1016/j.apgeochem.2026.106679","url":null,"abstract":"<div><div>Rising global temperature is exerting a notable effect on the photosynthetic process of marine algae, which in turn may affect the structure and distribution of marine primary producers on a global scale. Sea surface temperature exerts a multifaceted influence on the growth, composition and structure of dinoflagellate, as well as on inorganic carbon fixation. This paper investigates the effect of temperature change on the growth of one dinoflagellate specie <em>Scrippsiella trochoidea</em>, and examines the variations in the organic carbon structure of its cell wall. This study is pioneering in its exploration of the impact of temperature on the structural organisation of organic matter in the dinoflagellate, with a particular focus on methylene carbon. The results indicate that <em>Scrippsiella trochoidea</em> exhibits a propensity to synthesise elevated levels of aliphatic compounds and proteins, particularly long-chain aliphatic biopolymers, at elevated incubation temperature. Moverover, a highly positive correlation is identified between the incubation temperature and the methylene carbon structure in the alkyl carbon structure. Such compositional and structural changes can have a significant impact on the potential yield of oil and gas through the process of algal pyrolysis.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106679"},"PeriodicalIF":3.4,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024055","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}
Pub Date : 2026-01-16DOI: 10.1016/j.apgeochem.2026.106704
Yaping Zhang , Kunfu Pi , Xianjun Xie , Ziyi Xiao , Jianbo Shi , Qianyong Liang , Yuxia Li
Arsenic (As) mobility and fate in geogenic contaminated groundwater can be impacted by co-occurring microplastics and dissolved organic matter (DOM). However, molecular mechanisms and kinetic constraints underlying microplastics-DOM-As interactions remain to be deciphered. By employing polystyrene microplastics (PSMPs) as a representative type of microplastics found in Datong high-As groundwater (As >10 μg/L), this research investigated thermodynamically and kinetically adsorption of As(III) and As(V) by microplastics as well as the critical effects of DOM. At groundwater pH of 6.8, adsorption of both As species occurred via oxygen-containing functional groups on PSMPs surfaces, but As(V) adsorption was quicker and greater than As(III) due to macrocolloids-like nature of PSMPs. Humic acids (HA) and fulvic acids (FA) compete for adsorption sites, alter surface properties, and facilitate aggregation of PSMPs, thereby reducing available surface sites for As binding. Interactions among PSMPs, HA/FA, and As species lead to formation of complexes including PSMPs-FA/HA-As and FA/HA-As. Furthermore, HA and FA can change the diffusion coefficients and boundary layer thickness of As within PSMPs pores to alter adsorption kinetics. Our results provide novel mechanistic insights into joint roles of PSMPs and DOM in As mobilization/immobilization dynamics within geogenic contaminated groundwater. Moreover, this research consolidates theoretical foundation for understanding influences of emerging contaminants on environmental geochemical behaviors of geogenic As in pumped aquifers.
微塑料和溶解性有机物（DOM）的共存影响了砷在地源污染地下水中的迁移和归宿。然而，微塑料- dom - as相互作用的分子机制和动力学约束仍有待破译。以大同市高砷地下水（as >10 μg/L）中具有代表性的聚苯乙烯微塑料（PSMPs）为研究对象，研究了微塑料对as （III）和as (V)的热力学和动力学吸附以及DOM的临界效应。在地下水pH为6.8时，两种As均通过含氧官能团吸附在PSMPs表面，但由于PSMPs的大胶体性质，As(V)的吸附速度更快且大于As（III）。腐植酸（HA）和黄腐酸（FA）竞争吸附位点，改变表面性质，促进PSMPs聚集，从而减少可用的表面As结合位点。PSMPs、HA/FA和As之间的相互作用导致PSMPs-FA/HA-As和FA/HA-As复合物的形成。此外，HA和FA可以改变PSMPs孔隙中As的扩散系数和边界层厚度，从而改变吸附动力学。我们的研究结果为PSMPs和DOM在地质污染地下水中As的动员/固定动力学中的联合作用提供了新的机制见解。此外，本研究为认识新兴污染物对抽水蓄水层地质砷环境地球化学行为的影响奠定了理论基础。
{"title":"Influences of microplastic-dissolved organic matter-arsenic interactions on arsenic fate in geogenic contaminated groundwater: Mechanistic insights from kinetic-thermodynamic investigations and modeling","authors":"Yaping Zhang , Kunfu Pi , Xianjun Xie , Ziyi Xiao , Jianbo Shi , Qianyong Liang , Yuxia Li","doi":"10.1016/j.apgeochem.2026.106704","DOIUrl":"10.1016/j.apgeochem.2026.106704","url":null,"abstract":"<div><div>Arsenic (As) mobility and fate in geogenic contaminated groundwater can be impacted by co-occurring microplastics and dissolved organic matter (DOM). However, molecular mechanisms and kinetic constraints underlying microplastics-DOM-As interactions remain to be deciphered. By employing polystyrene microplastics (PSMPs) as a representative type of microplastics found in Datong high-As groundwater (As >10 μg/L), this research investigated thermodynamically and kinetically adsorption of As(III) and As(V) by microplastics as well as the critical effects of DOM. At groundwater pH of 6.8, adsorption of both As species occurred via oxygen-containing functional groups on PSMPs surfaces, but As(V) adsorption was quicker and greater than As(III) due to macrocolloids-like nature of PSMPs. Humic acids (HA) and fulvic acids (FA) compete for adsorption sites, alter surface properties, and facilitate aggregation of PSMPs, thereby reducing available surface sites for As binding. Interactions among PSMPs, HA/FA, and As species lead to formation of complexes including PSMPs-FA/HA-As and FA/HA-As. Furthermore, HA and FA can change the diffusion coefficients and boundary layer thickness of As within PSMPs pores to alter adsorption kinetics. Our results provide novel mechanistic insights into joint roles of PSMPs and DOM in As mobilization/immobilization dynamics within geogenic contaminated groundwater. Moreover, this research consolidates theoretical foundation for understanding influences of emerging contaminants on environmental geochemical behaviors of geogenic As in pumped aquifers.</div></div>","PeriodicalId":8064,"journal":{"name":"Applied Geochemistry","volume":"198 ","pages":"Article 106704"},"PeriodicalIF":3.4,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024059","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}
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