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Peltola, Pasi
Publications (10 of 40) Show all publications
Yu, C., Peltola, P., Nystrand, M. I., Virtasalo, J. J., Österholm, P., Ojala, A. E. K., . . . Åström, M. E. (2016). Arsenic removal from contaminated brackish sea water by sorption onto Al hydroxides and Fe phases mobilized by land-use. Science of the Total Environment, 542, 923-934
Open this publication in new window or tab >>Arsenic removal from contaminated brackish sea water by sorption onto Al hydroxides and Fe phases mobilized by land-use
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2016 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 542, p. 923-934Article in journal (Refereed) Published
Abstract [en]

This study examines the spatial and temporal distribution patterns of arsenic (As) in solid and aqueous materials along the mixing zone of an estuary, located in the south-eastern part of the Bothnian Bay and fed by a creek running through an acid sulfate (AS) soil landscape. The concentrations of As in solution form (<1 kDa) increase steadily from the creek mouth to the outer estuary, suggesting that inflowing seawater, rather than AS soil, is the major As source in the estuary. In sediments at the outer estuary, As was accumulated and diagenetically cycled in the surficial layers, as throughout much of the Bothnian Bay. In contrast, in sediments in the inner estuary, As concentrations and accumulation rates showed systematical peaks at greater depths. These peaks were overall consistent with the temporal trend of past As discharges from the Ronnskar smelter and the accompanied As concentrations in past sea-water of the Bothnian Bay, pointing to a connection between the historical smelter activities and the sediment-bound As in the inner estuary. However, the concentrations and accumulation rates of As peaked at depths where the smelter activities had already declined, but a large increase in the deposition of Al hydroxides and Fe phases occurred in response to intensified land-use in the mid 1960's and early 1970's. This correspondence suggests that, apart from the inflowing As-contaminated seawater, capture by Al hydroxides, Fe hydroxides and Fe-organic complexes is another important factor for As deposition in the inner estuary. After accumulating in the sediment, the solid-phase As was partly remobilized, as reflected by increased pore-water As concentrations, a process favored by As(V) reduction and high concentrations of dissolved organic matter. (C) 2015 Elsevier B.V. All rights reserved.

Keyword
Arsenic, Estuarine sediments, The Bothnian Bay, Ronnskar smelter, Acid sulfate soils
National Category
Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-48801 (URN)10.1016/j.scitotenv.2015.11.013 (DOI)000365602100093 ()26558848 (PubMedID)2-s2.0-84946616230 (Scopus ID)
Available from: 2016-01-20 Created: 2016-01-15 Last updated: 2017-12-08Bibliographically approved
Berger, T., Yu, C., Drake, H., Peltola, P., Svensson, D. & Åström, M. E. (2016). Fluorine geochemistry of quaternary deposits in a nemo-boreal catchment with elevated dissolved fluoride in surface waters and groundwater. Journal of Geochemical Exploration, 170, 148-156
Open this publication in new window or tab >>Fluorine geochemistry of quaternary deposits in a nemo-boreal catchment with elevated dissolved fluoride in surface waters and groundwater
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2016 (English)In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 170, p. 148-156Article in journal (Refereed) Published
Abstract [en]

This study focuses on fluorine (F) concentrations and solid-phase speciation in Quaternary deposits, including till, sorted sediments (gravel, sand, clay/silt) and organic-rich soil types, in an area in southeast Sweden underlain by 1.8 Ga granites and quartz monzodiorites with moderate F concentrations (0.11-0.13 wt%) and an outcrop (5 km in diameter) of 1.45 Ga granite (the Gotemar granite) with high to very high F concentrations (0.38-0.54 wt%). Eighteen <1 to 5 m thick profiles were sampled both upon and in the vicinity of the Gotemar granite. The F concentrations in the Quaternary deposits were considerably lower than in the underlying fresh bedrock, with the overall highest concentrations in glacial clay having values up to 660 ppm. A contributing factor to the low F concentrations in the till, as compared to the fresh rock, is release and leaching of fluoride (F-) during alteration of biotite and amphiboles to secondary minerals. Sequential chemical extractions showed that the F in the Quaternary deposits exists mainly in the residual fraction, and also to a substantial extent in phases extractable with hydroxylamine hydrochloride in the till and in phases extractable with Na pyrophosphate in the organic-rich soil types. These features indicate that after release via alteration of primary minerals, F- has to a significant extent been scavenged by Fe/Al (and perhaps Mn) oxyhydroxides in the till and by labile organic matter in the organic soil types. The high F- concentrations previously reported for stream waters and regolith groundwaters in the area are due to weathering and leaching of the Quaternary deposits and discharge of fluoride-rich waters from underlying bedrock fractures. (C) 2016 Elsevier B.V. All rights reserved.

Keyword
Fluorite, Gotemar granite, Water-rock interaction, Sequential chemical extraction, X-ray diffraction
National Category
Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:lnu:diva-58200 (URN)10.1016/j.gexplo.2016.09.003 (DOI)000386405300012 ()2-s2.0-84987950342 (Scopus ID)
Available from: 2016-11-18 Created: 2016-11-18 Last updated: 2017-11-29Bibliographically approved
Yu, C., Virtasalo, J. J., Österholm, P., Burton, E. D., Peltola, P., Ojala, A. E. K., . . . Åström, M. E. (2016). Manganese accumulation and solid-phase speciation in a 3.5 m thick mud sequence from the estuary of an acidic and Mn-rich creek, northern Baltic Sea. Chemical Geology, 437, 56-66
Open this publication in new window or tab >>Manganese accumulation and solid-phase speciation in a 3.5 m thick mud sequence from the estuary of an acidic and Mn-rich creek, northern Baltic Sea
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2016 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 437, p. 56-66Article in journal (Refereed) Published
Abstract [en]

In sediments, manganese (Mn) is typically enriched in the form of authigenic Mn hydroxides at the water-sediment interface where intensive redox cycling of Mn occurs. Here we show, based on existing hydrochemical and geochemical (sediment core) data and new detailed chemical and mineralogical characterization of a 3.5 m long sediment core from a Boreal estuary, that the behavior of Mn can be profoundly different and more complex in estuarine settings receiving an abundance of terrestrial Mn. The most notable feature in the 3.5 m long sediment core is two depth intervals (60-155 cm and 181-230 cm) where there are strong fine-scale variations in Mn concentrations with peaks episodically reaching up to 10-25 g kg(-1) and 6.7-12 g kg(-1), respectively. X-ray absorption spectroscopy and sequential chemical extraction show that Mn occurs mainly as authigenic rhodochrosite at these two depth intervals and is mainly surface-sorbed in other sections with relatively low and stable Mn concentrations. The data suggests that the strong fine-scale variations in Mn concentrations are a reflection of the extent of formation and settling of Mn hydroxides, the precursors of the authigenic rhodochrosite (and also of the surface-sorbed Mn), rather than Mn input to the estuary or redox-related Mn translocation within the sediment. There was agreement between the results of linear combination fitting of extended X-ray absorption fine structure data and a 7-step sequential chemical extraction (SCE) in terms of quantification of surface-sorbed Mn species, whereas the SCE experiment failed to fractionate a majority of rhodochrosite into SCE step-2 (1M NH4-acetate at pH 6), which is frequently employed to dissolve carbonate. We ascribe this discrepancy to only partial dissolution of rhodochrosite in the weakly acidic (pH = 6) NH4-acetate leach. (C) 2016 Elsevier B.V. All rights reserved.

Keyword
Estuarine sediments, Mn speciation, X-ray absorption spectroscopy, Rhodochrosite, Acid sulfate soil
National Category
Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-55055 (URN)10.1016/j.chemgeo.2016.05.016 (DOI)000378936800006 ()2-s2.0-84973131081 (Scopus ID)
Available from: 2016-07-26 Created: 2016-07-22 Last updated: 2017-12-08Bibliographically approved
Yu, C., Virtasalo, J. J., Karlsson, T., Peltola, P., Osterholm, P., Burton, E. D., . . . Åström, M. E. (2015). Iron behavior in a northern estuary: Large pools of non-sulfidized Fe(II) associated with organic matter. Chemical Geology, 413, 73-85
Open this publication in new window or tab >>Iron behavior in a northern estuary: Large pools of non-sulfidized Fe(II) associated with organic matter
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2015 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 413, p. 73-85Article in journal (Refereed) Published
Abstract [en]

The estuaries of the Northern Baltic Sea (Gulf of Bothnia) receive an abundance of diagenetically reactive catchment-derived Fe, which is to a large degree complexed with organicmatter or present as Fe (hydr-) oxides. However, our understanding of sedimentary Fe diagenesis in these estuaries is limited. To address this limitation, the present study examines Fe geochemistry in a 3.5-m-thick estuarine benthic mud layer and three samples of suspended particulate matter of a catchment on the eastern Gulf of Bothnia. The age-depth model of the mud, constructed on the basis of sedimentary features as well as Cs-137 and aquatic plant C-14 determinations, revealed a high average rate of sedimentation (5 cm . yr(-1)) for the upper mud unit (0-182.5 cm, corresponding to 1973-2011), in response to intensive land-use (ditching) in the catchment since the 1960s and 1970s. The intensive land-use has resulted in a strong increase in the Fe accumulation rates, but has not caused a recognizable impact on the diagenetic processes of Fe including features such as degree of sulfidization and solid-phase partitioning. Iron X-ray absorption spectroscopy (XAS) indicated that in the suspended particulate matter, large proportions (47-58%) of Fe occur as Fe(III)-organic complexes and 2-line ferrihydrite. In the mud, the former is completely reduced, and reactive Fe (defined via extraction with 1 MHCl) was high throughout (52-68%, median = 61%) and strongly dominated by Fe(II). This reactive Fe(II) pool was sulfidized to only a limited extent (degree of reactive sulfidization = 11-26%, median = 17%). This phenomenon is attributed to the brackish-water conditions (i.e. low in sulfate) and the abundant input of reactive Fe(III) from the catchment, leading to a surplus of dissolved Fe2+ over dissolved sulfide in the sediment. The low availability of dissolved sulfide, in combination with the high average sedimentation rate, limits the formation of intermediate reduced sulfur compounds at the water-sediment interface, thereby retarding the conversion of FeS into pyrite (ratios of pyrite-S to AVS = 0.17-1.73, median = 0.37; degree of pyritization = 1-17%, median = 3%). Iron XAS, in combination with wavelet transform analysis, of representative sediment segments from the upper and lower mud units suggests that the non-sulfidized Fe(II) pool is dominantly complexed by organic matter, with the remaining Fe(II) occurring as mackinawite. This has implications for the understanding of early Fe diagenesis in settings with a high input of organic matter and relatively low supply of sulfate. (C) 2015 Elsevier B.V. All rights reserved.

Keyword
Iron diagenesis, X-ray absorption spectroscopy (XAS), Sulfidization, Gulf of Bothnia, Sediments, Non-sulfidized reactive Fe pools
National Category
Geochemistry
Research subject
Natural Science
Identifiers
urn:nbn:se:lnu:diva-46890 (URN)10.1016/j.chemgeo.2015.08.013 (DOI)000361845700007 ()2-s2.0-84940867984 (Scopus ID)
Available from: 2015-10-26 Created: 2015-10-26 Last updated: 2017-12-01Bibliographically approved
Berger, T., Mathurin, F. A., Gustafsson, J. P., Peltola, P. & Åström, M. E. (2015). The impact of fluoride on Al abundance and speciation in boreal streams. Chemical Geology, 409, 118-124
Open this publication in new window or tab >>The impact of fluoride on Al abundance and speciation in boreal streams
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2015 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 409, p. 118-124Article in journal (Refereed) Published
Abstract [en]

The impact of fluoride on the abundance and speciation of aluminium (Al) was investigated in three boreal streams characterised by overall high concentrations of fluoride and dissolved organic matter. Stream-water sampling was carried out several times a year for at least 4 years, and a chemical equilibrium model (Visual MINTEQ) was applied in order to model the proportion of colloidal and organically/inorganically complexed Al in the waters. The Al concentrations in filtered (0.45 mu m) water samples were inversely correlated with pH, and reached values up to approximately 1 mg/L during low pH conditions (pH < 6.0). In a stream with high fluoride concentrations, as compared to a similar stream with only moderately elevated fluoride concentrations, the Al concentrations were consistently elevated. For the stream with high concentrations of fluoride and Al, the model predicted both high concentrations and proportions of Al-fluoride complexation. This prediction indicates that high fluoride levels contribute to raise both the Al abundance and the ratio of inorganic to organic Al complexation in stream water. In contrast, for another stream with high fluoride concentrations and consistently high (near neutral) pH, there was no evidence of fluoride affecting Al concentration or complexation. These results show that it is important to focus future studies on the role of high levels of dissolved fluoride on both the speciation and the toxicity of Al in stream water.

National Category
Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-44138 (URN)10.1016/j.chemgeo.2015.05.013 (DOI)000358525500012 ()2-s2.0-84930942419 (Scopus ID)
Available from: 2015-06-12 Created: 2015-06-12 Last updated: 2017-12-07Bibliographically approved
Mathurin, F. A., Drake, H., Tullborg, E.-L., Berger, T., Peltola, P., Kalinowski, B. E. & Åström, M. E. (2014). High cesium concentrations in groundwater in the upper 1.2 km of fractured crystalline rock - Influence of groundwater origin and secondary minerals. Geochimica et Cosmochimica Acta, 132, 187-213
Open this publication in new window or tab >>High cesium concentrations in groundwater in the upper 1.2 km of fractured crystalline rock - Influence of groundwater origin and secondary minerals
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2014 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 132, p. 187-213Article in journal (Refereed) Published
Abstract [en]

Dissolved and solid phase cesium (Cs) was studied in the upper 1.2 km of a coastal granitoid fracture network on the Baltic Shield (Aspo Hard Rock Laboratory and Laxemar area, SE Sweden). There unusually high Cs concentrations (up to 5-6 mu g L-1) occur in the low-temperature (<20 degrees C) groundwater. The material includes water collected in earlier hydro-chemical monitoring programs and secondary precipitates (fracture coatings) collected on the fracture walls, as follows: (a) hydraulically pristine fracture groundwater sampled through 23 surface boreholes equipped for the retrieval of representative groundwater at controlled depths (Laxemar area), (b) fracture groundwater affected by artificial drainage collected through 80 boreholes drilled mostly along the Aspo Hard Rock Laboratory (underground research facility), (c) surface water collected in local streams, a lake and sea bay, and shallow groundwater collected in 8 regolith boreholes, and (d) 84 new specimens of fracture coatings sampled in cores from the Aspo HRL and Laxemar areas. The groundwater in each area is different, which affects Cs concentrations. The highest Cs concentrations occurred in deep-seated saline groundwater (median Aspo HRL: 4.1 mu g L-1; median Laxemar: 3.7 mu g L-1) and groundwater with marine origin (Aspo HRL: 4.2 mu g L-1). Overall lower, but variable, Cs concentrations were found in other types of groundwater. The similar concentrations of Cs in the saline groundwater, which had a residence time in the order of millions of years, and in the marine groundwater, which had residence times in the order of years, shows that duration of water-rock interactions is not the single and primary control of dissolved Cs in these systems. The high Cs concentrations in the saline groundwater is ascribed to long-term weathering of minerals, primarily Cs-enriched fracture coatings dominated by illite and mixed-layer clays and possibly wall rock micaceous minerals. The high Cs concentrations in the groundwater of marine origin are, in contrast, explained by relatively fast cation exchange reactions. As indicated by the field data and predicted by 1D solute transport modeling, alkali cations with low-energy hydration carried by intruding marine water are capable of (NH4+ in particular and K+ to some extent) replacing Cs+ on frayed edge (FES) sites on illite in the fracture coatings. The result is a rapid and persistent (at least in the order of decades) buildup of dissolved Cs concentrations in fractures where marine water flows downward. The identification of high Cs concentrations in young groundwater of marine origin and the predicted capacity of NH4+ to displace Cs from fracture solids are of particular relevance in the disposal of radioactive nuclear waste deep underground in crystalline rock. (C) 2014 Elsevier Ltd. All rights reserved.

National Category
Earth and Related Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-34476 (URN)10.1016/j.gca.2014.02.001 (DOI)000334832100012 ()2-s2.0-84895973626 (Scopus ID)
Available from: 2014-05-28 Created: 2014-05-28 Last updated: 2017-12-05Bibliographically approved
Yu, C., Lavergren, U., Peltola, P., Drake, H., Bergbäck, B. & Åström, M. E. (2014). Retention and transport of arsenic, uranium and nickel in a black shale setting revealed by a long-term humidity cell test and sequential chemica extractions. Chemical Geology, 363, 134-144
Open this publication in new window or tab >>Retention and transport of arsenic, uranium and nickel in a black shale setting revealed by a long-term humidity cell test and sequential chemica extractions
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2014 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 363, p. 134-144Article in journal (Refereed) Published
Abstract [en]

The dispersion of acidic solutions with high levels of metals/metalloids, as a result of oxidative weathering of pyritic geomaterials, is a major environmental problem in areas where these materials are widely distributed and/or were historically mined. In this study, four types of materials encountered in an old black-shale mining area (unweathered black shale, weathered black shale, burnt black shale, and lime-mixed burnt black shale) were subjected to a long-term (up to 137 weeks) humidity cell test (HCT) combined with sequential chemical extractions (SCE), with the aim of examining geochemical controls on the release of Ni, U and As in this kind of pyritic settings. By combining the results of HCT and SCE as well as previously collected groundwater data, it is clearly shown that the degree of pyrite oxidation is the only major factor controlling the release of Ni, resulting in its highly elevated concentrations in acidic groundwaters. Although U followed a similar leaching pattern as observed for Ni and occurred abundantly in acidic groundwaters, a major decrease in the chemical fraction targeting exchangeable and carbonate phases, and a correlation of U concentrations with redox potential in groundwaters collectively suggest that the release of U was largely controlled by the solubilization of sorbed/carbonate U phases by oxidation to the highly soluble form (UO22+). As compared to the HCT, the SCE procedures used in this study delivered equally good estimates of Ni, U and S cumulatively leached, suggesting the strength of the SCE in terms of quantification of these elements during the weathering of pyritic geomaterials. Arsenic X-ray absorption near-edge structure spectroscopy shows that during the HCT (oxidation and leaching) of unweathered black shale, As was oxidized from its reduced form (having the oxidation state of -1 and most probably occurs as arsenian pyrite) to As(+5). Compared to the two cationic metals, As was released to a very limited extent and was not detectable in the leachates having pH between 6 and 3. This is because As was speciated exclusively as negatively-charged oxyanions in these leachates as predicted by MINTEQ modeling, thus was effectively attenuated by concurrently formed iron minerals. These minerals include mainly schwertmannite and K-jarosite as observed by SEM-EDS and also predicted by MINTEQ modeling. Elevated levels of As exclusively occurred in the groundwaters from one tube strongly impacted by seawater intrusion. This was regarded as a reflection of loosely-sorbed As oxyanions reliberated through ion exchange with seawater chloride. In this context, sea-level rise on a global scale as a potential driver for arsenic remobilization in low-lying coastal areas deserves further attention.

Keyword
Black shale; Sequential chemical extractions; Humidity cell test; Oxidative weathering
National Category
Earth and Related Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-31841 (URN)10.1016/j.chemgeo.2013.11.003 (DOI)000329408900011 ()2-s2.0-84888425651 (Scopus ID)
Available from: 2014-01-30 Created: 2014-01-30 Last updated: 2017-12-06Bibliographically approved
Augustsson, A., Gaillard, M.-J., Peltola, P., Mazier, F., Bergbäck, B. & Saarinen, T. (2013). Effects of land use and climate change on erosion intensity and sediment geochemistry at Lake Lehmilampi, Finland. The Holocene, 23(9), 1247-1259
Open this publication in new window or tab >>Effects of land use and climate change on erosion intensity and sediment geochemistry at Lake Lehmilampi, Finland
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2013 (English)In: The Holocene, ISSN 0959-6836, E-ISSN 1477-0911, Vol. 23, no 9, p. 1247-1259Article in journal (Refereed) Published
Abstract [en]

This paper aims to evaluate the possible relationships between erosion intensity and changes in climate and land use during the past 5.5 cal. k years at Lake Lehmilampi, eastern Finland. In this study we compare a detailed geochemical sediment record with (1) forest and land use history inferred from the first pollen and charcoal records from Lake Lehmilampi, and (2) existing archaeological surveys and independent proxy-records of climate change in the study region. The physical and geochemical sediment parameters examined include grain size analysis data and 23 chemical elements, determined with four selective extractions and ICP-MS. There are indications of possible human impact in the lake catchment as early as the Neolithic period, c. 3000-2550 bc, but the first undisputable signs are dated to 1800-100 bc. Cereal pollen reappears at c. ad 1700 and increases rapidly until c. ad 1950. The Holocene Thermal Maximum, its end c. 2000 bc, and the Medieval Climate Anomaly' were major climate events that had a prominent effect on erosion intensity, while human impact was a more significant factor during the period 3000 bc-ad 800 and from ad 1500 onwards. Although signs of changes in erosion intensity found in the sediment were small in this small catchment, they were significant enough to have a clear impact on the fraction of potentially mobile element species. This fraction increases with decreasing erosion intensity, which is probably related to a higher degree of chemical weathering and leaching during periods of decreased erosion.

National Category
Geochemistry
Research subject
Environmental Science, Environmental Chemistry
Identifiers
urn:nbn:se:lnu:diva-25585 (URN)10.1177/0959683613484615 (DOI)000325711000004 ()2-s2.0-84881569710 (Scopus ID)
Available from: 2013-05-09 Created: 2013-05-09 Last updated: 2017-12-06Bibliographically approved
Åström, M. E., Österholm, P., Gustafsson, J. P., Nystrand, M., Peltola, P., Nordmyr, L. & Boman, A. (2012). Attenuation of rare earth elements in a boreal estuary. Geochimica et Cosmochimica Acta, 96, 105-119
Open this publication in new window or tab >>Attenuation of rare earth elements in a boreal estuary
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2012 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 96, p. 105-119Article in journal (Refereed) Published
Abstract [en]

This study focuses on attenuation of rare earth elements (REE) when a boreal creek, acidified and loaded with REE and other metals as a result of wetland drainage, empties into a brackish-water estuary (salinity < 6 parts per thousand). Surface water was collected in a transect from the creek mouth to the outer estuary, and settling (particulate) material in sediment traps moored at selected locations in the estuary. Ultrafiltration, high-resolution ICP-MS and modeling were applied on the waters, and a variety of chemical reagents were used to extract metals from the settling material. Aluminium, Fe and REE transported by the acidic creek were extensively removed in the inner/central estuary where the acidic water was neutralised, whereas Mn was relatively persistent in solution and thus redistributed to particles and deposited further down the estuary. The REE removal was caused by several contemporary mechanisms: co-precipitation with oxyhydroxides (mainly Al but also Fe), complexation with flocculating humic substances and sorption to suspended particles. Down estuary the dissolved REE pool, remaining after removal, was fractionated: the < 1 kDa pool became depleted in the middle REE and the colloidal (0.45 mu m-1 kDa) pool depleted in the middle and heavy REE. This fractionation was controlled by the removal process, such that those REE with highest affinity for the settling particles became most depleted in the remaining dissolved pool. Modeling, based on Visual MINTEQ version 3.0 and the Stockholm Humic Model after revision and updating, predicted that the dissolved (< 0.45 mu m) REE pool in the estuary is bound almost entirely to humic substances. Acid sulphate soils, the source of the REE and other metals in the creek water, are widespread on coastal plains worldwide and therefore the REE attenuation patterns and mechanisms identified in the studied estuary are relevant for recognition of similar geochemical processes and conditions in a variety of coastal locations. (C) 2012 Elsevier Ltd. All rights reserved.

National Category
Geochemistry
Research subject
Environmental Science, Environmental Chemistry
Identifiers
urn:nbn:se:lnu:diva-22693 (URN)10.1016/j.gca.2012.08.004 (DOI)000310427200008 ()2-s2.0-84867343859 (Scopus ID)
Available from: 2012-12-05 Created: 2012-12-05 Last updated: 2017-12-07Bibliographically approved
Yu, C., Peng, B., Peltola, P., Xiaoyan Tang, T. & Shurong, X. (2012). Effect of weathering on abundance and release of potentially toxic elements in soils developed on Lower Cambrian black shales, P. R. China. Environmental Geochemistry and Health, 34(3), 375-390
Open this publication in new window or tab >>Effect of weathering on abundance and release of potentially toxic elements in soils developed on Lower Cambrian black shales, P. R. China
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2012 (English)In: Environmental Geochemistry and Health, ISSN 0269-4042, E-ISSN 1573-2983, Vol. 34, no 3, p. 375-390Article in journal (Refereed) Published
Abstract [en]

This paper examines the geochemical features of 8 soil profiles developed on metalliferous black shales distributed in the central parts of the South China black shale horizon. The concentrations of 21 trace elements and 8 major elements were determined using ICP-MS and XRF, respectively, and weathering intensity (W) was calculated according to a new technique recently proposed in the literature. The data showed that the black shale soils inherited a heterogeneous geochemical character from their parent materials. A partial least square regression model and EFbedrock (enrichment factor normalized to underlying bedrock) indicated that W was not a major control in the redistribution of trace metals. Barium, Sn, Cu, V, and U tended to be leached in the upper soil horizons and trapped by Al and Fe oxides, whereas Sb, Cd, and Mo with negative EF values across the whole profiles may have been leached out during the first stage of pedogenesis (mainly weathering of black shale). Compared with the Chinese average soils, the soils were strongly enriched in the potentially toxic metals Mo, Cd, Sb, Sn, U, V, Cu, and Ba, among which the 5 first listed were enriched to the highest degrees. Elevated concentrations of these toxic metals can have a long-term negative effect on human health, in particular, the soils in mining areas dominated by strongly acidic conditions. As a whole, the black shale soils have much in common with acid sulfate soils. Therefore, black shale soils together with acid sulfate soils deserve more attention in the context of metal exposure and human health.

Place, publisher, year, edition, pages
Springer, 2012
National Category
Earth and Related Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-16665 (URN)10.1007/s10653-011-9398-y (DOI)2-s2.0-84859502982 (Scopus ID)
Available from: 2012-01-09 Created: 2012-01-09 Last updated: 2017-12-08Bibliographically approved
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