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An improved quantitative and qualitative understanding of the interaction of per- and polyfluoroalkyl substances (PFASs) and short-range ordered Fe (hydr)oxides is crucial for environmental risk assessment in environments low in natural organic matter. Here, we present data on the pH-dependent sorption behavior of 12 PFASs onto ferrihydrite. The nature of the binding mechanisms was investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and by phosphate competition experiments. Sulfur K-edge XANES spectroscopy showed that the sulfur atom of the head group of the sulfonated PFASs retained an oxidation state of +V after adsorption. Furthermore, the XANES spectra did not indicate any involvement of inner-sphere surface complexes in the sorption process. Adsorption was inversely related to pH (p < 0.05) for all PFASs (i.e., C3–C5 and C7–C9 perfluorocarboxylates, C4, C6, and C8 perfluorosulfonates, perfluorooctane sulfonamide, and 6:2 and 8:2 fluorotelomer sulfonates). This was attributed to the pH-dependent charge of the ferrihydrite surface, as reflected in the decrease of surface ζ-potential with increasing pH. The importance of surface charge for PFAS adsorption was further corroborated by the observation that the adsorption of PFASs decreased upon phosphate adsorption in a way that was consistent with the decrease in ferrihydrite ζ-potential. The results show that ferrihydrite can be an important sorbent for PFASs with six or more perfluorinated carbons in acid environments (pH ≤ 5), particularly when phosphate and other competitors are present in relatively low concentrations.
Hugo Campos-Pereira; Dan B. Kleja; Carin Sjöstedt; Lutz Ahrens; Wantana Klysubun; Jon Petter Gustafsson. The Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) onto Ferrihydrite Is Governed by Surface Charge. Environmental Science & Technology 2020, 54, 15722 -15730.
AMA StyleHugo Campos-Pereira, Dan B. Kleja, Carin Sjöstedt, Lutz Ahrens, Wantana Klysubun, Jon Petter Gustafsson. The Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) onto Ferrihydrite Is Governed by Surface Charge. Environmental Science & Technology. 2020; 54 (24):15722-15730.
Chicago/Turabian StyleHugo Campos-Pereira; Dan B. Kleja; Carin Sjöstedt; Lutz Ahrens; Wantana Klysubun; Jon Petter Gustafsson. 2020. "The Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) onto Ferrihydrite Is Governed by Surface Charge." Environmental Science & Technology 54, no. 24: 15722-15730.
Millions of tons of bottom ash (BA) is generated from incineration of industrial and municipal solid waste each year within EU. The magnitude of leaching of metals like Cu and Zn is critical for hazard and risk assessment of these ashes. Although speciation of metals is a key factor to understand and predict metal leaching, speciation of Cu and Zn in BA is not well known. In this study six metal separated and carbonized BA were investigated by a combination of X-ray absorption spectroscopy, X-ray diffraction, leaching/extraction tests, and geochemical modelling. Five of the BA were from grate boilers and one from a fluidized bed incinerator. The aims were to identify similarities in Cu and Zn speciation and to identify main species. The combination of several techniques was necessary to draw conclusions about speciation and displayed coherent results. A similar speciation of Cu and Zn was indicated in the five studied grate boiler ashes although the proportions between species may vary. Copper(II) oxide and Cu metal were the main Cu species in all BA. Zinc(II) oxide and willemite (Zn2SiO4) were identified in grate boiler ashes. The fluidized bed ash contained Zn-Si-minerals and possibly franklinite or gahnite, while the Zn(II) oxide content was low, if any. The results have implications for classification and risk assessment of MIBA.
Charlotta Tiberg; Carin Sjöstedt; Karin Karlfeldt Fedje. Speciation of Cu and Zn in bottom ash from solid waste incineration studied by XAS, XRD, and geochemical modelling. Waste Management 2020, 119, 1 .
AMA StyleCharlotta Tiberg, Carin Sjöstedt, Karin Karlfeldt Fedje. Speciation of Cu and Zn in bottom ash from solid waste incineration studied by XAS, XRD, and geochemical modelling. Waste Management. 2020; 119 ():1.
Chicago/Turabian StyleCharlotta Tiberg; Carin Sjöstedt; Karin Karlfeldt Fedje. 2020. "Speciation of Cu and Zn in bottom ash from solid waste incineration studied by XAS, XRD, and geochemical modelling." Waste Management 119, no. : 1.
Phosphate competes with arsenate for sorption sites on poorly crystalline iron and aluminum (hydr)oxides. The competition has implications e.g. for the management of arsenic-contaminated soil and water. Phosphate competition with arsenate on mixed phases containing both iron and aluminum (hydr)oxides has rarely been investigated. Here, the phosphate competition with arsenate on mixtures of poorly crystalline aluminum hydroxide (Alhox) and ferrihydrite (Fh), was investigated in batch experiments at pH 6.5. X-ray absorption spectroscopy (XAS) was performed on the phosphorus and arsenic K edges, which offered a unique insight in the partitioning of arsenate and phosphate on mixed Alhox-Fh sorbents. Under the studied conditions the sorption capacity of the mixed sorbents (per mol Al or Fe) increased at higher Alhox to Fh ratios. The XAS measurements provided direct evidence that phosphate competed more effectively with arsenate for sorption sites on Alhox than on Fh. For example, in a mixture with 50% of both sorbents and with similar additions of arsenate and phosphate, 71% of the oxyanions adsorbed on Fh and 46% on Alhox were arsenate. Consequently, phosphate may mobilize arsenate more easily from mixed iron-aluminum matrices that are rich in aluminum.
Charlotta Tiberg; Carin Sjöstedt; Ann Kristin Eriksson; Wantana Klysubun; Jon Petter Gustafsson. Phosphate competition with arsenate on poorly crystalline iron and aluminum (hydr)oxide mixtures. Chemosphere 2020, 255, 126937 .
AMA StyleCharlotta Tiberg, Carin Sjöstedt, Ann Kristin Eriksson, Wantana Klysubun, Jon Petter Gustafsson. Phosphate competition with arsenate on poorly crystalline iron and aluminum (hydr)oxide mixtures. Chemosphere. 2020; 255 ():126937.
Chicago/Turabian StyleCharlotta Tiberg; Carin Sjöstedt; Ann Kristin Eriksson; Wantana Klysubun; Jon Petter Gustafsson. 2020. "Phosphate competition with arsenate on poorly crystalline iron and aluminum (hydr)oxide mixtures." Chemosphere 255, no. : 126937.
Arsenic (As) is reported to be effectively sorbed onto natural organic matter (NOM) via thiol coordination and polyvalent metal cation bridged ternary complexation. However, the extent of sorption via complexation with oxygen-containing functional groups of NOM is poorly understood. By equilibrating arsenite, arsenate, and monothioarsenate with purified model-peat, followed by As K-edge X-ray absorption spectroscopic analysis, this study shows that complexation with oxygen-containing functional groups can be an additional or alternative mode of As sorption to NOM. The extent of complexation was highest for arsenite, followed by monothioarsenate and arsenate. Complexation was higher at pH 7.0 compared to 4.5 for arsenite and arsenate, and vice versa for monothioarsenate due to partial transformation to arsenite at pH 4.5. Modeling of the As K-edge EXAFS data revealed that As…C interatomic distances were relatively longer in arsenate- (2.83 ± 0.01 Å) and monothioarsenate-treated peat (2.80 ± 0.02 Å) compared to arsenite-treatments (2.73 ± 0.01 Å). This study suggests that arsenite was predominantly complexed with carboxylic groups, while arsenate and monothioarsenate were complexed with alcoholic groups of the peat. This study further implies that in systems, where NOM is the major sorbent, arsenate and monothioarsenate can have higher mobility than arsenite.
Ashis Biswas; Johannes Besold; Carin Sjöstedt; Jon Petter Gustafsson; Andreas C. Scheinost; Britta Planer-Friedrich. Complexation of Arsenite, Arsenate, and Monothioarsenate with Oxygen-Containing Functional Groups of Natural Organic Matter: An XAS Study. Environmental Science & Technology 2019, 53, 10723 -10731.
AMA StyleAshis Biswas, Johannes Besold, Carin Sjöstedt, Jon Petter Gustafsson, Andreas C. Scheinost, Britta Planer-Friedrich. Complexation of Arsenite, Arsenate, and Monothioarsenate with Oxygen-Containing Functional Groups of Natural Organic Matter: An XAS Study. Environmental Science & Technology. 2019; 53 (18):10723-10731.
Chicago/Turabian StyleAshis Biswas; Johannes Besold; Carin Sjöstedt; Jon Petter Gustafsson; Andreas C. Scheinost; Britta Planer-Friedrich. 2019. "Complexation of Arsenite, Arsenate, and Monothioarsenate with Oxygen-Containing Functional Groups of Natural Organic Matter: An XAS Study." Environmental Science & Technology 53, no. 18: 10723-10731.
Laboratory-based leaching tests are frequently used for in situ risk assessments of contaminant leaching to groundwater and surface waters. This study evaluated the ability of three standardised leaching tests to assess leaching of lead (Pb), zinc (Zn), arsenic (As) and antimony (Sb) from four intact soil profiles, by considering particulate (0.45–8 μm; percolation test), colloidal (10 kDa–0.45 μm) and truly dissolved (<10 kDa) fractions of these elements. Deionised water was used as the percolation test leachant, while either deionised water or 1 mM CaCl2 was used in batch tests. Data from an irrigation experiment were used as reference. The results indicated that in percolation tests, leachate should be collected at a liquid:solid ratio (L/S) range of 2–10, instead of 0–0.5 or 0.5–2. Even at L/S = 2–10, the percolation test overestimated total Pb concentration, mainly because of greater mobilisation of particle-bound Pb, but appeared suitable for categorising soils into high/low risk with respect to mobilisation of particulate and colloidal contaminants. The batch test performed better with CaCl2 than with deionised water when standard membrane filtration (0.45 μm) was used, as the high Ca2+ concentration reduced colloidal mobilisation, avoiding overestimation of concentrations of elements such as Pb. However, the higher Ca2+ concentration and lower pH could result in overestimated concentrations of weakly sorbed elements, e.g. Zn.
Åsa Löv; Mats Larsbo; Carin Sjöstedt; Geert Cornelis; Jon Petter Gustafsson; Dan B. Kleja. Evaluating the ability of standardised leaching tests to predict metal(loid) leaching from intact soil columns using size-based elemental fractionation. Chemosphere 2019, 222, 453 -460.
AMA StyleÅsa Löv, Mats Larsbo, Carin Sjöstedt, Geert Cornelis, Jon Petter Gustafsson, Dan B. Kleja. Evaluating the ability of standardised leaching tests to predict metal(loid) leaching from intact soil columns using size-based elemental fractionation. Chemosphere. 2019; 222 ():453-460.
Chicago/Turabian StyleÅsa Löv; Mats Larsbo; Carin Sjöstedt; Geert Cornelis; Jon Petter Gustafsson; Dan B. Kleja. 2019. "Evaluating the ability of standardised leaching tests to predict metal(loid) leaching from intact soil columns using size-based elemental fractionation." Chemosphere 222, no. : 453-460.
Due to the low solubility of lead (Pb) in many soils, colloidal and particulate transport may have large effects on Pb leaching. However, the role of colloidal and particulate transport varies considerably between soils and the mechanisms controlling mobilisation are complex and poorly known. Furthermore, increased frequency of high-intensity rainfall events is expected in some parts of Europe and North America in response to climate change, which might increase the mobilisation of particles and colloids. In this work, we investigated transport of particulate (>0.45 μm), colloidal (10 kDa-0.45 μm) and truly dissolved (<10 kDa) Pb in an irrigation experiment on intact soil columns from four historically contaminated soils. We also investigated the effect of irrigation intensity (2–20 mm h−1) on Pb leaching in these fractions. The mechanism binding Pb on particles and colloids was evaluated by extended X-ray absorption fine structure (EXAFS) spectroscopy and geochemical modelling. A 10-fold increase in irrigation intensity brought about at most a three-fold change in leached particulate and colloidal Pb concentrations. In contrast, the fraction of leached Pb associated with particles and colloids varied by one order of magnitude between soils. Hence, the results suggest that it is more important to consider soil type than potential future increases in rainfall. For one soil with high concentrations of both arsenic (As) and Pb, geochemical modelling indicated that mimetite, Pb5(AsO4)3Cl(s), was the major Pb species in the colloidal and particulate fractions. For the other three soils, EXAFS of Pb on isolated particles and colloids indicated that ferrihydrite was a major phase-sorbing Pb and this was supported by geochemical equilibrium modelling. Thus geochemical modelling can be used to indicate the speciation of Pb in particles and colloids leached in intact soils.
Åsa Löv; Geert Cornelis; Mats Larsbo; Ingmar Persson; Carin Sjöstedt; Jon Petter Gustafsson; Kristin Boye; Dan B. Kleja. Particle- and colloid-facilitated Pb transport in four historically contaminated soils - Speciation and effect of irrigation intensity. Applied Geochemistry 2018, 96, 327 -338.
AMA StyleÅsa Löv, Geert Cornelis, Mats Larsbo, Ingmar Persson, Carin Sjöstedt, Jon Petter Gustafsson, Kristin Boye, Dan B. Kleja. Particle- and colloid-facilitated Pb transport in four historically contaminated soils - Speciation and effect of irrigation intensity. Applied Geochemistry. 2018; 96 ():327-338.
Chicago/Turabian StyleÅsa Löv; Geert Cornelis; Mats Larsbo; Ingmar Persson; Carin Sjöstedt; Jon Petter Gustafsson; Kristin Boye; Dan B. Kleja. 2018. "Particle- and colloid-facilitated Pb transport in four historically contaminated soils - Speciation and effect of irrigation intensity." Applied Geochemistry 96, no. : 327-338.
C. Sjöstedt; Å. Löv; Z. Olivecrona; K. Boye; D.B. Kleja. Improved geochemical modeling of lead solubility in contaminated soils by considering colloidal fractions and solid phase EXAFS speciation. Applied Geochemistry 2018, 92, 110 -120.
AMA StyleC. Sjöstedt, Å. Löv, Z. Olivecrona, K. Boye, D.B. Kleja. Improved geochemical modeling of lead solubility in contaminated soils by considering colloidal fractions and solid phase EXAFS speciation. Applied Geochemistry. 2018; 92 ():110-120.
Chicago/Turabian StyleC. Sjöstedt; Å. Löv; Z. Olivecrona; K. Boye; D.B. Kleja. 2018. "Improved geochemical modeling of lead solubility in contaminated soils by considering colloidal fractions and solid phase EXAFS speciation." Applied Geochemistry 92, no. : 110-120.
While metal sorption mechanisms have been studied extensively for soil surface horizons, little information exists for subsoils, for example Spodosol Bs horizons. Here the sorption of cadmium(II), copper(II) and lead(II) to seven Bs horizons from five sites was studied. Extended X-ray absorption fine structure (EXAFS) spectroscopy showed that cadmium(II) and lead(II) were bound as inner-sphere complexes to organic matter. Addition of o-phosphate (to 1 μmol l−1) did not result in any significant enhancement of metal sorption, nor did it influence EXAFS speciation. An assemblage model using the SHM and CD-MUSIC models overestimated metal sorption for six out of seven soil samples. To agree with experimental results, substantial decreases (up to 8-fold) had to be made for the fraction ‘active organic matter’, fHS, while the point-of-zero charge (PZC) of ferrihydrite had to be increased. The largest decreases of fHS were found for the soils with the lowest ratio of pyrophosphate-to oxalate-extractable Al (Alpyp/Alox), suggesting that in these soils, humic and fulvic acids were to a large extent inaccessible for metal sorption. The low reactivity of ferrihydrite towards lead(II) can be explained by potential spillover effects from co-existing allophane, but other factors such as ferrihydrite crystallisation could not be ruled out. In conclusion, organic matter was the predominant sorbent for cadmium(II), copper(II) and lead(II). However, for lead(II) the optimised model suggests additional, but minor, contributions from Fe (hydr)oxide surface complexes. These results will be important to correctly model metal sorption in spodic materials.
Charlotta Tiberg; Carin Sjöstedt; Jon Petter Gustafsson. Metal sorption to Spodosol Bs horizons: Organic matter complexes predominate. Chemosphere 2018, 196, 556 -565.
AMA StyleCharlotta Tiberg, Carin Sjöstedt, Jon Petter Gustafsson. Metal sorption to Spodosol Bs horizons: Organic matter complexes predominate. Chemosphere. 2018; 196 ():556-565.
Chicago/Turabian StyleCharlotta Tiberg; Carin Sjöstedt; Jon Petter Gustafsson. 2018. "Metal sorption to Spodosol Bs horizons: Organic matter complexes predominate." Chemosphere 196, no. : 556-565.
Chromium is a common soil contaminant and, although it has been studied widely, questions about its speciation and dissolutions kinetics remain unanswered. We combined information from an irrigation experiment performed with intact soil columns with data from batch experiments to evaluate solubility and mobilization mechanisms of Cr(III) in a historically contaminated soil (>65 years). Particulate and colloidal Cr(III) forms dominated transport in this soil, but their concentrations were independent of irrigation intensity (2-20 mm h(-1)). Extended X-ray absorption fine structure (EXAFS) measurements indicated that Cr(III) associated with colloids and particles, and with the solid phase, mainly existed as dimeric hydrolyzed Cr(III) bound to natural organic matter. Dissolution kinetics of this species were fast (≤1 day) at low pH (<3) and slightly slower (≤5 days) at neutral pH. Furthermore, it proved possible to describe the solubility of the dimeric Cr(III) organic matter complex with a geochemical equilibrium model using only generic binding parameters, opening the way for use of geochemical models in risk assessments of Cr(III)-contaminated sites.
Åsa Löv; Carin Sjöstedt; Mats Larsbo; Ingmar Persson; Jon Petter Gustafsson; Geert Cornelis; Dan B. Kleja. Solubility and transport of Cr(III) in a historically contaminated soil – Evidence of a rapidly reacting dimeric Cr(III) organic matter complex. Chemosphere 2017, 189, 709 -716.
AMA StyleÅsa Löv, Carin Sjöstedt, Mats Larsbo, Ingmar Persson, Jon Petter Gustafsson, Geert Cornelis, Dan B. Kleja. Solubility and transport of Cr(III) in a historically contaminated soil – Evidence of a rapidly reacting dimeric Cr(III) organic matter complex. Chemosphere. 2017; 189 ():709-716.
Chicago/Turabian StyleÅsa Löv; Carin Sjöstedt; Mats Larsbo; Ingmar Persson; Jon Petter Gustafsson; Geert Cornelis; Dan B. Kleja. 2017. "Solubility and transport of Cr(III) in a historically contaminated soil – Evidence of a rapidly reacting dimeric Cr(III) organic matter complex." Chemosphere 189, no. : 709-716.
Environmental contextVanadium, a metal pollutant from fossil fuels and slags, may be toxic, thereby necessitating an understanding of its environmental chemistry. One important factor that controls the mobility and bioavailability of vanadium is its binding to iron oxides. This study focuses on the characterization and modelling of vanadium adsorption onto ferrihydrite. The new model can be used to simulate the transport and bioavailability of vanadium in the environment. AbstractThe mobility of vanadium in the environment is influenced by sorption to metal (hydr)oxides, especially those containing iron. The aim of this study is to understand the adsorption behaviour of vanadium on poorly ordered (two-line) ferrihydrite (Fh). A further objective was to determine the binding mechanism of vanadate(V) to ferrihydrite surfaces in aqueous suspension to constrain the CD-MUSIC surface complexation model. Vanadium adsorption to ferrihydrite was evaluated by batch experiments which included series with different Fh-to-V ratios and pH values. Vanadate(V) adsorption was also evaluated in the presence of phosphate to compete with vanadate(V) for the available surface sites on ferrihydrite. In agreement with earlier studies, vanadate(V) was strongly adsorbed to ferrihydrite and the adsorption increased with decreasing pH. In the presence of phosphate, less vanadate(V) was adsorbed. Analysis by X-ray absorption near-edge structure spectroscopy revealed that the adsorbed vanadium was tetrahedral vanadate(V), VO4, regardless of whether vanadate(V) or vanadyl(IV) was added to the system. Spectra collected by extended X-ray absorption fine structure spectroscopy showed that vanadate(V) is bound primarily as an edge-sharing bidentate complex with V⋯Fe distances around 2.8Å. Based on this information, a surface complexation model was set up in which three bidentate vanadate(V) complexes with different degrees of protonation were included. The model provided a satisfactory description of vanadate(V) adsorption over most of the pH and concentration ranges studied, also in the presence of competing phosphate ions.
Maja A. Larsson; Ingmar Persson; Carin Sjöstedt; Jon Petter Gustafsson. Vanadate complexation to ferrihydrite: X-ray absorption spectroscopy and CD-MUSIC modelling. Environmental Chemistry 2017, 14, 141 -150.
AMA StyleMaja A. Larsson, Ingmar Persson, Carin Sjöstedt, Jon Petter Gustafsson. Vanadate complexation to ferrihydrite: X-ray absorption spectroscopy and CD-MUSIC modelling. Environmental Chemistry. 2017; 14 (3):141-150.
Chicago/Turabian StyleMaja A. Larsson; Ingmar Persson; Carin Sjöstedt; Jon Petter Gustafsson. 2017. "Vanadate complexation to ferrihydrite: X-ray absorption spectroscopy and CD-MUSIC modelling." Environmental Chemistry 14, no. 3: 141-150.
J Gustafsson; C Sjöstedt. Revised best-fit parameters for arsenate adsorption to ferrihydrite. Arsenic in the Environment - Proceedings 2016, 139 -140.
AMA StyleJ Gustafsson, C Sjöstedt. Revised best-fit parameters for arsenate adsorption to ferrihydrite. Arsenic in the Environment - Proceedings. 2016; ():139-140.
Chicago/Turabian StyleJ Gustafsson; C Sjöstedt. 2016. "Revised best-fit parameters for arsenate adsorption to ferrihydrite." Arsenic in the Environment - Proceedings , no. : 139-140.
C Tiberg; C Sjöstedt; A Eriksson; J Gustafsson. Phosphate effects on arsenate binding to soil hydroxides. Arsenic in the Environment - Proceedings 2016, 145 -146.
AMA StyleC Tiberg, C Sjöstedt, A Eriksson, J Gustafsson. Phosphate effects on arsenate binding to soil hydroxides. Arsenic in the Environment - Proceedings. 2016; ():145-146.
Chicago/Turabian StyleC Tiberg; C Sjöstedt; A Eriksson; J Gustafsson. 2016. "Phosphate effects on arsenate binding to soil hydroxides." Arsenic in the Environment - Proceedings , no. : 145-146.
This paper evaluates the arsenic adsorption characteristics of a macroporous polymer coated with coprecipitated iron-aluminium hydroxides (MHCMP). The MHCMP adsorbent-composite fits best with a pseudo-second order model for As(III) and a pseudo-first order kinetic model for As(V). The MHCMP shows a maximum adsorption capacity of 82.3 and 49.6mgAs/g adsorbent for As(III) and As(V) ions respectively, and adsorption followed the Langmuir model. Extended X-ray absorption fine structure showed that binding of As(III) ions were confirmed to take place on the iron hydroxides coated on the MHCMP, whereas for As(V) ions the binding specificity could not be attributed to one particular metal hydroxide. As(III) formed a bidentate mononuclear complex with Fe sites, whereas As(V) indicated on a bidentate binuclear complex with Al sites or monodentate with Fe sites on the adsorbent. The column experiments were run in a well water spiked with a low concentration of As(III) (100μg/L) and a commercially available adsorbent (GEH(®)102) based on granular iron-hydroxide was used for comparison. It was found that the MHCMP was able to treat 7 times more volume of well water as compared to GEH(®)102, maintaining the threshold concentration of less than 10μgAs/L, indicating that the MHCMP is a superior adsorbent.
Prashanth Suresh Kumar; Roxana Quiroga Flores; Carin Sjöstedt; Linda Önnby. Arsenic adsorption by iron–aluminium hydroxide coated onto macroporous supports: Insights from X-ray absorption spectroscopy and comparison with granular ferric hydroxides. Journal of Hazardous Materials 2016, 302, 166 -174.
AMA StylePrashanth Suresh Kumar, Roxana Quiroga Flores, Carin Sjöstedt, Linda Önnby. Arsenic adsorption by iron–aluminium hydroxide coated onto macroporous supports: Insights from X-ray absorption spectroscopy and comparison with granular ferric hydroxides. Journal of Hazardous Materials. 2016; 302 ():166-174.
Chicago/Turabian StylePrashanth Suresh Kumar; Roxana Quiroga Flores; Carin Sjöstedt; Linda Önnby. 2016. "Arsenic adsorption by iron–aluminium hydroxide coated onto macroporous supports: Insights from X-ray absorption spectroscopy and comparison with granular ferric hydroxides." Journal of Hazardous Materials 302, no. : 166-174.
Unique quantitative bioaccessibility data has been generated, and the influence of surface/material and test media characteristics on the elemental release process were assessed for silicon containing materials in specific synthetic body fluids at certain time periods at a fixed loading. The metal release test protocol, elaborated by the KTH team, has previously been used for classification, ranking, and screening of different alloys and metals. Time resolved elemental release of Si, Fe and Al from particles, sized less than 50 µm, of two grades of metallurgical silicon (high purity silicon, SiHG, low purity silicon, SiLG), an alloy (ferrosilicon, FeSi) and a mineral (aluminium silicate, AlSi) has been investigated in synthetic body fluids of varying pH, composition and complexation capacity, simple models of for example dermal contact and digestion scenarios. Individual methods for analysis of released Si (as silicic acid, Si(OH)4) in synthetic body fluids using GF-AAS were developed for each fluid including optimisation of solution pH and graphite furnace parameters. The release of Si from the two metallurgical silicon grades was strongly dependent on both pH and media composition with the highest release in pH neutral media. No similar effect was observed for the FeSi alloy or the aluminium silicate mineral. Surface adsorption of phosphate and lactic acid were believed to hinder the release of Si whereas the presence of citric acid enhanced the release as a result of surface complexation. An increased presence of Al and Fe in the material (low purity metalloid, alloy or mineral) resulted in a reduced release of Si in pH neutral media. The release of Si was enhanced for all materials with Al at their outermost surface in acetic media.
Gunilla Herting; Tao Jiang; Carin Sjöstedt; Inger Odnevall Wallinder. Release of Si from Silicon, a Ferrosilicon (FeSi) Alloy and a Synthetic Silicate Mineral in Simulated Biological Media. PLOS ONE 2014, 9, e107668 .
AMA StyleGunilla Herting, Tao Jiang, Carin Sjöstedt, Inger Odnevall Wallinder. Release of Si from Silicon, a Ferrosilicon (FeSi) Alloy and a Synthetic Silicate Mineral in Simulated Biological Media. PLOS ONE. 2014; 9 (9):e107668.
Chicago/Turabian StyleGunilla Herting; Tao Jiang; Carin Sjöstedt; Inger Odnevall Wallinder. 2014. "Release of Si from Silicon, a Ferrosilicon (FeSi) Alloy and a Synthetic Silicate Mineral in Simulated Biological Media." PLOS ONE 9, no. 9: e107668.
Chromium is a common soil contaminant, and it often exists as chromium(III). However, limited information exists on the coordination chemistry and stability of chromium(III) complexes with natural organic matter (NOM). Here, the complexation of chromium(III) to mor layer material and to Suwannee River Fulvic Acid (SRFA) was investigated using EXAFS spectroscopy and batch experiments. The EXAFS results showed a predominance of monomeric chromium(III)-NOM complexes at low pH ( 5 there were polynuclear chromium(III)-NOM complexes with Cr···Cr interactions at 2.98 Å and for SRFA also at 3.57 Å, indicating the presence of dimers (soil) and tetramers (SRFA). The complexation of chromium(III) to NOM was intermediate between that of iron(III) and aluminum(III). Chromium(III) complexation was slow at pH < 4: three months or longer were required to reach equilibrium. The results were used to constrain chromium-NOM complexation in the Stockholm Humic Model (SHM): a monomeric complex dominated at pH < 5, whereas a dimeric complex dominated at higher pH. The optimized constant for the monomeric chromium(III) complex was in between those of the iron(III) and aluminum(III) NOM complexes. Our study suggests that chromium(III)-NOM complexes are important for chromium speciation in many environments.QC 20140313
Jon Petter Gustafsson; Ingmar Persson; Aidin Geranmayeh Oromieh; Joris W. J. Van Schaik; Carin Sjöstedt; Dan Berggren Kleja. Chromium(III) Complexation to Natural Organic Matter: Mechanisms and Modeling. Environmental Science & Technology 2014, 48, 1753 -1761.
AMA StyleJon Petter Gustafsson, Ingmar Persson, Aidin Geranmayeh Oromieh, Joris W. J. Van Schaik, Carin Sjöstedt, Dan Berggren Kleja. Chromium(III) Complexation to Natural Organic Matter: Mechanisms and Modeling. Environmental Science & Technology. 2014; 48 (3):1753-1761.
Chicago/Turabian StyleJon Petter Gustafsson; Ingmar Persson; Aidin Geranmayeh Oromieh; Joris W. J. Van Schaik; Carin Sjöstedt; Dan Berggren Kleja. 2014. "Chromium(III) Complexation to Natural Organic Matter: Mechanisms and Modeling." Environmental Science & Technology 48, no. 3: 1753-1761.
Stijn Baken; Carin Sjöstedt; Jon Petter Gustafsson; Piet Seuntjens; Nele Desmet; Jan De Schutter; Erik Smolders. Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams. Applied Geochemistry 2013, 39, 59 -68.
AMA StyleStijn Baken, Carin Sjöstedt, Jon Petter Gustafsson, Piet Seuntjens, Nele Desmet, Jan De Schutter, Erik Smolders. Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams. Applied Geochemistry. 2013; 39 ():59-68.
Chicago/Turabian StyleStijn Baken; Carin Sjöstedt; Jon Petter Gustafsson; Piet Seuntjens; Nele Desmet; Jan De Schutter; Erik Smolders. 2013. "Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams." Applied Geochemistry 39, no. : 59-68.
Transport of lead(II) and copper(II) ions in soil is affected by the soil phosphorus status. Part of the explanation may be that phosphate increases the adsorption of copper(II) and lead(II) to iron (hydr)oxides in soil, but the details of these interactions are poorly known. Knowledge about such mechanisms is important, for example, in risk assessments of contaminated sites and development of remediation methods. We used a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and surface complexation modeling with the three-plane CD-MUSIC model to study the effect of phosphate on sorption of copper(II) and lead(II) to ferrihydrite. The aim was to identify the surface complexes formed and to derive constants for the surface complexation reactions. In the batch experiments phosphate greatly enhanced the adsorption of copper(II) and lead(II) to ferrihydrite at pH < 6. The largest effects were seen for lead(II). Based on interpretation of the EXAFS spectra edge-sharing bidentate copper(II) or lead(II) complexes predominated in the single-sorbate systems with ferrihydrite. Lead(II) EXAFS spectra suggested a distinct change of coordination in the presence of phosphate, i.e. the signal from edge-sharing complexes diminished and a longer Pb center dot center dot center dot Fe distance appeared at about 4 angstrom. A similar, but less pronounced, pattern was observed for copper(II). Based on the results from interpretation of EXAFS spectra and surface complexation modeling with the CD-MUSIC model the enhanced sorption in presence of phosphate was most satisfactorily explained by the appearance of ternary metal-phosphate complexes in which the metal interacts directly with the surface. In conclusion, geochemical models used for simulating trace element behavior in acidic environments seem to require ternary metal-phosphate surface complexes to properly describe partitioning of metals between solution and the solid phase.QC 20131025
Charlotta Tiberg; Carin Sjöstedt; Ingmar Persson; Jon Petter Gustafsson. Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite. Geochimica et Cosmochimica Acta 2013, 120, 140 -157.
AMA StyleCharlotta Tiberg, Carin Sjöstedt, Ingmar Persson, Jon Petter Gustafsson. Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite. Geochimica et Cosmochimica Acta. 2013; 120 ():140-157.
Chicago/Turabian StyleCharlotta Tiberg; Carin Sjöstedt; Ingmar Persson; Jon Petter Gustafsson. 2013. "Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite." Geochimica et Cosmochimica Acta 120, no. : 140-157.
Carin Sjöstedt; Cecilia Andrén; Jens Fölster; Jon Petter Gustafsson. Modelling of pH and inorganic aluminium after termination of liming in 3000 Swedish lakes. Applied Geochemistry 2013, 35, 221 -229.
AMA StyleCarin Sjöstedt, Cecilia Andrén, Jens Fölster, Jon Petter Gustafsson. Modelling of pH and inorganic aluminium after termination of liming in 3000 Swedish lakes. Applied Geochemistry. 2013; 35 ():221-229.
Chicago/Turabian StyleCarin Sjöstedt; Cecilia Andrén; Jens Fölster; Jon Petter Gustafsson. 2013. "Modelling of pH and inorganic aluminium after termination of liming in 3000 Swedish lakes." Applied Geochemistry 35, no. : 221-229.
Carin Sjöstedt; Ingmar Persson; Dean Hesterberg; Dan Berggren Kleja; Hans Borg; Jon Petter Gustafsson. Iron speciation in soft-water lakes and soils as determined by EXAFS spectroscopy and geochemical modelling. Geochimica et Cosmochimica Acta 2013, 105, 172 -186.
AMA StyleCarin Sjöstedt, Ingmar Persson, Dean Hesterberg, Dan Berggren Kleja, Hans Borg, Jon Petter Gustafsson. Iron speciation in soft-water lakes and soils as determined by EXAFS spectroscopy and geochemical modelling. Geochimica et Cosmochimica Acta. 2013; 105 ():172-186.
Chicago/Turabian StyleCarin Sjöstedt; Ingmar Persson; Dean Hesterberg; Dan Berggren Kleja; Hans Borg; Jon Petter Gustafsson. 2013. "Iron speciation in soft-water lakes and soils as determined by EXAFS spectroscopy and geochemical modelling." Geochimica et Cosmochimica Acta 105, no. : 172-186.
A consistent chemical equilibrium model that calculates pH from charge balance constraints and aluminum and iron speciation in the presence of natural organic matter is presented. The model requires input data for total aluminum, iron, organic carbon, fluoride, sulfate, and charge balance ANC. The model is calibrated to pH measurements (n = 322) by adjusting the fraction of active organic matter only, which results in an error of pH prediction on average below 0.2 pH units. The small systematic discrepancy between the analytical results for the monomeric aluminum fractionation and the model results is corrected for separately for two different fractionation techniques (n = 499) and validated on a large number In = 3419) of geographically widely spread samples all over Sweden. The resulting average error for inorganic monomeric aluminum is around 1 mu M. In its present form the model is the first internally consistent modeling approach for Sweden and may now be used as a tool for environmental quality management Soil gibbsite with a log *K-s of 8.29 at 25 degrees C together with a pH dependent loading function that uses molar Al/C ratios describes the amount of aluminum in solution in the presence of organic matter if the pH is roughly above 6.0.QC 20101210
Carin Sjöstedt; Jon Petter Gustafsson; Stephan J. Köhler. Chemical Equilibrium Modeling of Organic Acids, pH, Aluminum, and Iron in Swedish Surface Waters. Environmental Science & Technology 2010, 44, 8587 -8593.
AMA StyleCarin Sjöstedt, Jon Petter Gustafsson, Stephan J. Köhler. Chemical Equilibrium Modeling of Organic Acids, pH, Aluminum, and Iron in Swedish Surface Waters. Environmental Science & Technology. 2010; 44 (22):8587-8593.
Chicago/Turabian StyleCarin Sjöstedt; Jon Petter Gustafsson; Stephan J. Köhler. 2010. "Chemical Equilibrium Modeling of Organic Acids, pH, Aluminum, and Iron in Swedish Surface Waters." Environmental Science & Technology 44, no. 22: 8587-8593.