Thallium distribution in an estuary affected by acid mine drainage (AMD): The Ría de Huelva estuary (SW Spain)

Supplementary data to this article can be found online at https://doi. org/10.1016/j.envpol.2022.119448.This work was supported by the Spanish Ministry of Economy and Competitiveness under the research projects CAPOTE (MINECO; CGL 2017-86050-R) and TRAMPA (MINECO; PID 2020-119196RB-C21). C.R C´anovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC 2019- 027949-I. M.D. Basallote thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference IJC 2018-035056-I. A. Parviainen thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference IJCI-2016-27412. The comments and helpful criticisms of three anonymous reviewers and the support of Professor Wen-Xiong Wang (Editor) have considerably improved the original manuscript and are also gratefully acknowledged. Funding for open access charge: Universidad de Huelva/CBUA.This study investigates the behavior of Tl in the Ría de Huelva (SW Spain), one of the most metal polluted estuaries in the world. Dissolved Tl concentration displayed a general decrease across the estuary during the dry season (DS); from 5.0 to 0.34 μg/L in the Tinto and Odiel estuaries, respectively, to 0.02 μg/L in the channel where the rivers join. A slighter decrease was observed during the wet season (WS) (from 0.72 to 0.14 μg/L to 0.02 μg/L) due to the dilution effect of rainfalls in the watersheds. These values are 3 orders of magnitude higher than those reported in other estuaries worldwide. Different increases in Tl concentrations with salinity were observed in the upper reaches of the Tinto and Odiel estuaries, attributed to desorption processes from particulate matter. Chemical and mineralogical evidences of particulate matter, point at Fe minerals (i.e., jarosite) as main drivers of Tl particulate transport in the estuary. Unlike other estuaries worldwide, where a fast sorption process onto particulate matter commonly takes place, Tl is mainly desorbed from particulate matter in the Tinto and Odiel estuaries. Thus, Tl may be released back from jarositic particulate matter across the salinity gradient due to the increasing proportion of unreactive TlCl0 and K+ ions, which compete for adsorption sites with Tl+ at increasing salinities. A mixing model based on conservative elements revealed a 6-fold increase in Tl concentrations related to desorption processes. However, mining spills like that occurred in May 2017 may contribute to enhance dissolved and particulate Tl concentrations in the estuary as well as to magnify these desorption processes (up to around 1100% of Tl release), highlighting the impact of the mine spill on the remobilization of Tl from the suspended matter to the water column.CAPOTE (MINECO; CGL 2017-86050-R)TRAMPA (MINECO; PID 2020-119196RB-C21)Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC 2019- 027949-I.Postdoctoral Fellowship granted under application reference IJCI-2016-27412Funding for open access charge: Universidad de Huelva/CBU

Effects of estuarine water mixing on the mobility of trace elements in acid mine drainage leachates

This work was supported by the Spanish Ministry of Science and Innovation under the research project TRAMPA (PID2020-119196RB- C21). C.R. C´anovas, A. Parviainen and M.D. Basallote also acknowledge the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowships granted under application references RYC2019-027949-I, IJCI-2016-27412 and IJC2018-035056-I, respectively. We would also like to thank Dr. Geoff MacFarlane for the editorial handling and two anonymous reviewers for the support and comments that significantly improved the quality of the original paper. Funding for open access charge: Universidad de Huelva/CBUA.This research reports the effects of pH increase on contaminant mobility in acid mine drainage from the Iberian Pyrite Belt by seawater mixing in the laboratory, simulating the processes occurring in the Estuary of Huelva (SW Iberian Peninsula). Concentrations of Al, Fe, As, Cu and REY in mixing solutions significantly decreased with increasing pH. Schwertmannite precipitation at pH 2.5–4.0 led to the total removal of Fe(III) and As. Subsequently, iron-depleted solutions began to be controlled by precipitation of basaluminite at pH 4.5–6.0, which acted as a sink for Al, Cu and REY. Nevertheless, as the pH rises, schwertmannite becomes unstable and releases back to solution the previously retained As. Moreover, other elements (S, Zn, Cd, Ni and Co) behaved conservatively in mixing solutions with no participation in precipitation processes. Some toxic elements finally end up to the Atlantic Ocean contributing to the total pollutant loads and environmentally threatening the coastal areas

Are Cu isotopes a useful tool to trace metal sources and processes in acid mine drainage (AMD) context?

In the South-West Europe (Iberian Pyrite Belt), acid mine drainage (AMD) processes are especially problematic because they affect the environmental quality of watersheds, restricting the use of surface water. Recent studies have shown that Cu isotopes are fractionated during the oxidative dissolution of primary sulfide minerals and could be used to trace metal cycling. However the chemistry of Cu in such environment is complex because Cu is redistributed within numerous secondary minerals and strongly dependent on the hydroclimatic conditions that control key parameters (pH, redox conditions). Finally, it remains difficult to compare the various field studies and deliver some strong general tendencies because of these changing conditions. For these reasons, concerted studies on Cu isotopes fractionation in waters impacted by AMD may help to reveal the sources and transport pathways of this important pollutant. To address this issue, we used a representative scenario of strong contamination by AMD in the Iberian Pyrite Belt (SW Spain), the Cobica River. The aim of our study is to measure the Cu isotopes signature in the waters (river, mine lake, water draining waste) of the small Cobica River system (Huelva, Spain), sampled during a short period (8 h) to avoid any change in the hydro-climatic conditions. This provided an instantaneous image of the isotopic Cu signature in a small mining systems and helped us to constrain both the processes affecting Cu isotopes and their use a potential tracer of metals in contaminated environments.This work was supported by the french national programme EC2CO Biohefect/Ecodyn//Dril/MicrobiEen (INSU/CNRS, France), the Paul Sabatier University (France) and the Department of Mining, Mechanical, Energetic and Construction Engineering of the University of Huelva (Spain)

Heavy iron isotope composition of granites determined by high resolution MC-ICP-MS

International audienceHigh mass resolution multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was assessed for iron isotope measurement of natural samples after matrix separation by anion exchange chromatography. No remaining interferences were observed on the plateaus used for the mass spectrometric measurements. The approach developed and the instrument used permitted analyses in the static mode. Various mass bias corrections using Ni doping were tested, and even the assumption of similar fractionation factors for Fe and Ni did not produce significantly inaccurate data. However, the daily regression method between In Fe-57/(54) Fe and 1n(61)Ni/Ni-60 on the standard reference material IRMM-14 to characterize the instrumental mass bias appeared to give the best precision. The reproducibility observed over four months is about 0.013 parts per thousand/amu, 2 SD, on both delta(57)Fe/Fe-54 and delta(56)Fe/Fe-54 values, provided that each sample is analyzed at least six times. Accuracy, as estimated on interlaboratory comparison of natural samples that included geostandards, lies within this uncertainty. Among the bulk granitic rocks analysed, those with MgO below 0.6 wt.% and SiO2 above 71 wt.% have delta(57) Fe/Fe-54 values significantly heavier than the bulk mafic Earth. This shows that the iron isotope composition of terrestrial igneous rocks is more scattered than previously thought. There are good correlations between the Fe isotope composition and the MgO and SiO2 contents of the granitoids. These correlations are interpreted as reflecting the exsolution of late magmatic aqueous fluids from the granitic melt that preferentially removed the lighter isotopes of iron and enriched the residual magma in the heavier isotopes

Use of B isotopes as a tracer of anthropogenic emissions in the atmosphere of Paris, France

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Use of B isotopes as a tracer of anthropogenic emissions in the atmosphere of Paris, France

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Equilibrium mass-dependent isotope fractionation of antimony between stibnite and Sb secondary minerals: A first-principles study

International audienceAntimony (Sb) isotopes are gaining increasing interest for their potential as geochemical tracers in geological, environmental and archaeological studies. However, little is known about the parameters controlling Sb isotope fractionation, which is essential to interpret variations of isotopic signature in natural systems. In this study, equilibrium mass-dependent isotope fractionation factors (β-factor) were determined between different Sb-bearing minerals commonly found in mining environments including primary Sb sulphide (stibnite Sb 2 S 3) and its oxidation products (valentinite Sb 2 O 3 , senarmontite Sb 2 O 3 , cervantite Sb 2 O 4) and synthetic antimony pentoxide Sb 2 O 5. First-principles calculations within the Density Functional Theory (DFT) were performed with different functionals to test the robustness of the method. Among the studied minerals, stibnite has the lowest β-factor (ln(β) = 0.71 ‰ at 22°C), then β-factors progressively increase from valentinite (ln(β) = 1.64 ‰ at 22 °C), to senarmontite (ln(β) = 1.80 ‰ at 22 °C), cervantite (ln(β) = 2.20 ‰ at 22 °C) and antimony pentoxide (ln(β) = 3.03 ‰ at 22 °C). The parameters that most fractionate Sb isotopes are found to be i) the change of Sb oxidation state (Sb isotope ratio in Sb(V)-bearing minerals is higher than in Sb(III)-bearing minerals), ii) the change of first neighbour of Sb (Sb isotope ratio in Sb-O bonds is higher than in Sb-S bonds) and iii) distortion of the atomic Sb-O polyhedrons. The negligible differences in the β-factors obtained with different functionals showed the robustness of the approach for the calculation of β-factors, despite differences in the calculated mineral lattice and Raman frequencies. The results of this study provide a theoretical basis to interpret natural Sb isotope variations. In sulphide mining environments, the results suggest that a significant enrichment in the heavy isotope could occur during oxidative dissolution of stibnite and subsequent precipitation of Sb(III) and Sb(V) oxides. More generally, this work strongly supports that Sb isotopes may be a useful tracer of Sb transformation processes in nature

Amorphous Materials: Properties, Structure, and Durability{dagger} Arsenic enrichment in hydrous peraluminous melts: Insights from femtosecond laser ablation-inductively coupled plasma-quadrupole mass spectrometry, and in situ X-ray absorption fine structure spectroscopy

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Cu isotope records of Cu-based antifouling paints in sediment core profiles from the largest European Marina, The Port Camargue

The intensive use of copper (Cu) compounds as an alternative biocide in antifouling paints (APs) has resulted in wide Cu contamination into the marine environment, especially near marina harbor activities. In this work, the applicability of Cu isotopes to discriminate Cu origins related to the use of Cu-based APs in marine environments was tested. To this, Cu isotopes in APs, shipyard sludges, and sediment cores sampled in the Cu-contaminated Mediterranean marina of Port Camargue were determined. APs represent an important dominant anthropogenic source for metals in this site, making it ideal to test Cu isotopes as tracers. The overall isotope composition of four sediment cores and a surface sample varied between −0.13 and 0.44 ‰ (δ65Cu relative to NIST-976). Selected APs brands show a similar Cu concentration ~0.15 % and δ65Cu average of 0.54 ± 0.05 ‰. The plot of δ65Cu vs concentration for all datasets allowed dissociating natural and APs end-members. However, sample isotope systematics were not consistent with a conservative mixing binary source process. Heavily Cu-contaminated sediments show isotope signatures lighter than APs brands. However, the most Cu-contaminated sample, located directly above the careening area, shows a δ65Cu slightly lighter than APs (0.44 ‰ vs 0.54 ‰, respectively). Results suggest the preferential releasing of a heavy isotope pool by APs when these compounds are solubilized in seawater. The isotope fractionation was attributed to potential chemical Cu coordination changes during its elemental partition between paint and marina seawater and the fractionation induced by the organic ligands in the water column, before deposition. Further laboratory experiments are recommended to model the isotope fractionation mechanisms related to Cu release by APs. Because the APs' isotope signature is modified in marine environments, the use of Cu isotopes as tracers of AP in marine environments is challenging and needs more investigation

Evaluation of infrared femtosecond laser ablation for the analysis of geomaterials by ICP-MS

International audienceThe capabilities of an infrared (IR) Ti:sapphire femtosecond laser (approximate to 800 nm) to ablate and analyze geomaterials such as monazite, zircon and synthetic glass reference materials is evaluated, with emphasis on U/Pb ratio determinations useful for dating accessory minerals in rocks. We particularly discuss the influence of pulse duration ( respectively 60, 200, 350, 500, 670, 830, 2000 and 3000 fs) on the internal precision ( 2 min ablation), reproducibility over two weeks and accuracy of quadrupole ICP-MS measurements. The best results for all these criteria are obtained when using the shortest pulse duration ( 60 fs). It was found that internal precision and reproducibility were improved by a factor of 3 and 4, respectively, from picosecond to 60 fs pulsewidths. Reproducibility at this pulse duration for U/Pb ratio determinations is of 2% RSD or better, depending on the material analyzed, and this ratio is accurate within this uncertainty. Lead isotopic ratios also benefit from the shortest pulsewidth. They are measured at 60 fs with a precision (< 0.5% RSD) approaching the limitations of quadrupole ICP-MS. Preliminary data were also obtained using the 3rd harmonic (approximate to 266 nm) of the Ti: sapphire fundamental wavelength and they are compared with the infrared mode. There seems to be no obvious analytical benefit to switch from IR to UV in the femtosecond laser ablation regime. Analyses of zircon 91500 with IR pulses led to better repeatability, around 0.9% ( 10 values, 1 sigma), compared to 3% for the UV pulses. The accuracy appears to be comparable for the two wavelengths