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  • 1.
    Amakawa, Hiroshi
    et al.
    University of Tokyo.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Masuda, Akimasa
    University of Tokyo.
    Shimizu, Hiroshi
    University of Tokyo.
    Isotopic compositions of Ce, Nd and Sr in ferromanganese nodules from the Pacific and Atlantic Oceans, the Baltic and Barents Seas, and the Gulf of Bothnia1991In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 105, no 4, p. 554-565Article in journal (Refereed)
    Abstract [en]

    Ferromanganese nodules from the Pacific and Atlantic Oceans, the Barents and Baltic Seas, and the Gulf of Bothnia were analyzed for the isotopic compositions of Ce, Nd and Sr and the abundances of REE, Ba and Sr. REE patterns of Barents, Baltic and Bothnian samples show no Ce anomaly, or even a negative one, in contrast to the positive anomaly observed for the Pacific and Atlantic samples. Moreover, the Baltic and Bothnian samples have distinctly low εNd values; average εNd values of the four regions are as follows: Pacific -5, Barents -10, Atlantic -11 and Baltic inclusive of Gulf of Bothnia -19. The characteristic low εNd values of the Baltic samples are indicative of the influence of Precambrian rocks from the Baltic shield. Of particular interest is the feature of the Ce isotopic composition that εCe values of the samples from the Pacific are negative and those from the other three regions positive. This novel finding might suggest a difference in sources of Ce between the Pacific and other regions. These results demonstrate that Ce isotopic ratios can be a useful tracer in marine geochemistry, in combination with isotopic compositions of Nd and Sr.

  • 2. Amakawa, Hiroshi
    et al.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Masuda, Akimasa
    Shimizu, Hiroshi
    Isotopic compositions of Ce, Nd and Sr in ferromanganese nodules from various oceanic regions1992In: Abstracts : 29th International Geological Congress, Kyoto, Japan, 24 August - 3 September 1992, 1992, p. 613-Conference paper (Other academic)
  • 3.
    Andersson, Karen
    et al.
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Dahlqvist, Ralf
    Department of Geology and Geochemistry, Stockholm University.
    Turner, David
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Stolpe, Björn
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Larsson, Tobias
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Colloidal rare earth elements in a boreal river: changing sources and distributions during the spring flood2006In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 70, no 13, p. 3261-3274Article in journal (Refereed)
    Abstract [en]

    Variations in the physico-chemical speciation of the rare earth elements (REE) have been investigated in a subarctic boreal river during an intense spring flood event using prefiltered (<100 μm) samples, cross-flow (ultra)filtration (CFF), flow field-flow fractionation (FlFFF), and diffusive gradients in thin films (DGT). This combination of techniques has provided new information regarding the release and transport of the REE in river water. The colloidal material can be described in terms of two fractions dominated by carbon and iron, respectively. These two fractions, termed colloidal carrier phases, showed significant temporal changes in concentration and size distribution. Before the spring flood, colloidal carbon concentrations were low, the colloids being dominated by relatively large iron colloids. Colloidal concentrations increased sharply during the spring flood, with smaller carbon colloids dominating. Following the spring flood, colloidal concentrations decreased again, smaller carbon colloids still dominating. The REE are transported mainly in the particulate and colloidal phases. Before the spring flood, the REE composition of all measured fractions was similar to local till. During the spring flood, the REE concentrations in the colloidal and particulate fractions increased. The increase was most marked for the lighter REE, which therefore showed a strong enrichment when normalized to local till. Following the spring flood, the REE concentrations decreased again and reverted to a distribution similar to local till. These changes in the concentration and distributions of carbon iron and REE are interpreted in terms of changing hydrological flow paths in soil and bedrock which occur during the spring flood.

  • 4.
    Andersson, P. S.
    et al.
    Swedish Museum of Natural History.
    Porcelli, D.
    California Institute of Technology, Pasadena.
    Wasserburg, G. J.
    California Institute of Technology, Pasadena.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Particle transport of 234U-238U in the Kalix River and in the Baltic Sea1998In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 62, no 3, p. 385-392Article in journal (Refereed)
    Abstract [en]

    The role of particles for U isotope transport was investigated in the Kalix River watershed, a particle-poor, Fe/Mn-rich river in northern Sweden, and in the Baltic Sea estuary. Particles >0.45 μm are strongly enriched in U and contain 20-50% of the total riverine uranium budget and <1% of the total U in brackish waters (3-7 PSU). The particles have high δ234U which is close to that of dissolved U in the associated water, indicating that U on particles is dominantly nondetrital and isotopically exchanges rapidly with the ambient dissolved U. Particles at the river mouth are dominated by nondetrital Fe-Mn oxyhydroxides. Uranium and Fe are strongly correlated, clearly demonstrating that secondary Fe-oxyhydroxide is the major carrier of U in river water. There is no evidence for significant association of U with Mn-oxyhydroxide. Apparent U distribution coefficients ... were calculated for U between the authigenic Fe on particles and the solution. These values appear to be relatively constant throughout the year. This suggests an equilibrium between Fe in solution and authigenic Fe-oxyhydroxides on detrital particles. High values of .... calculated for one summer as well as high U concentrations in brackish waters can be explained by U scavenging by biogenic phases with low authigenic Fe content.

  • 5. Andersson, Per
    et al.
    Gustafsson, Örjan
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Porcelli, Don
    Widerlund, Anders
    Colloid-particle dynamics and transport of U-isotopes through the low-salinity (2002Conference paper (Other academic)
  • 6. Andersson, Per
    et al.
    Gustafsson, Örjan
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Roos, Per
    Colloid-particle dynamics and element transport through the low-salinity (2001Conference paper (Other academic)
  • 7. Andersson, Per
    et al.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A rapid preconcentration method for multielement analysis of natural freshwaters1991In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 25, no 5, p. 617-620Article in journal (Refereed)
    Abstract [en]

    This study describes an inexpensive and rapid preconcentration method which can be applied directly in the field. It is based on coprecipitation with magnesium hydroxide and has been applied for Al, Fe, Mn, Zn, Cu, Ni, V, Cr, Co, Cd, Be, Y, Sc and Yb in freshwaters. The method has been tested using inductively coupled plasma-atomic emission spectrometry (ICP-AES) by adding known amounts of metals to distilled water and natural freshwater. The detection limit for ICP-AES can be enhanced more than two orders of magnitude for Al, Y, Sc, Yb and approximately one order of magnitude for the other tested elements.

  • 8. Andersson, Per
    et al.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Seasonal variation in 87Sr/ 86Sr in the Kalix River northern Sweden: tracer for water and element sources1995In: European Union of Geosciences 8: oral and poster presentation, 1995, p. 244-Conference paper (Other academic)
  • 9. Andersson, Per
    et al.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Boström, Kurt
    Manganese in rain: throughfall and river water in North Swedish coniferous forest1989In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 70, no 15, p. 333-Article in journal (Other academic)
  • 10.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Dahlqvist, Ralf
    Swedish Museum of Natural History.
    Ingri, Johan
    Gustafsson, Örjan
    Stockholm University.
    The isotopic composition of Nd in a boreal river: a reflection of selective weathering and colloidal transport2001In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 65, no 4, p. 521-527Article in journal (Refereed)
    Abstract [en]

    In this study the Nd concentrations (CNd) from 18 months of weekly sampling of filtered water (<0.45 μm) in the Kalix River, northern Sweden, are reported with εNd(0) and 147Sm/144Nd ratios determined in samples representing major flow events as well as maxima and minima in CNd. The CNd varies by a factor of ten, between 200 pmol/L to 2100 pmol/L, and there is a strong relation between high discharge and high CNd. The Nd in the Kalix River is mainly transported on particles (>90%), dominated by a colloidal phase primarily composed of organic C and Fe. The εNd(0) and 147Sm/144Nd only vary within a narrow range, -27.1 to -24.8 and 0.103 to 0.110 respectively, with no obvious relationship to CNd and discharge. The εNd(0) and 147Sm/144Nd in the river water is significantly lower than in the unweathered till and average bedrock in the catchment and show a closer resemblance with the isotopic characteristics found in humic substances and plant material. These data show that the isotopic composition of Nd exported from a large boreal drainage basin does not directly reflect that of the bulk bedrock in the catchment. The isotopic composition is controlled by selective weathering and the Nd transport is dominated by organic colloidal particles.

  • 11.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Land, Magnus
    Widerlund, Anders
    Dahlqvist, Ralf
    Swedish Museum of Natural History.
    Gustafsson, Örjan
    Stockholm University.
    Weathering, transport, and sedimentation of rare earth elements and Nd-isotopes in a boreal river basin: brackish bay area2000In: Vol. 5, no 2, p. 146-Article in journal (Other academic)
  • 12. Andersson, Per S.
    et al.
    Porcelli, D.
    Gustafsson, Ö.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Wasserburg, G.J.
    Colloid and particle transport of U isotopes in the low salinity zone of a stable estuary1998In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 62A, p. 57-58Article in journal (Refereed)
  • 13.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Porcelli, D.
    California Institute of Technology, Pasadena.
    Gustafsson, Örjan
    Swedish Museum of Natural History.
    Ingri, Johan
    Wasserburg, G. J.
    California Institute of Technology, Pasadena.
    The importance of colloids for the behavior of uranium isotopes in the low-salinity zone of a stable estuary2001In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 65, no 1, p. 13-25Article in journal (Refereed)
    Abstract [en]

    Particle-mediated removal processes of U isotopes were investigated during spring flood discharge in the low-salinity zone (LSZ, up to 3 practical salinity units [psu]) of a stable estuary. A shipboard ultrafiltration cross-flow filtration (CFF) technique was used to separate particles (>0.2 μm) and colloids (between 3000 daltons (3 kD) and 0.2 μm) from ultrafiltered water (<3 kD) containing "dissolved" species. Sediment traps were used to collect sinking material. Concentration of Fe and organic C, which are indicators of the major U carrier phases, were used to interpret the behavior of 234U-238U during estuarine mixing. Colloids dominated the river water transport of U, carrying ≈90% of the U. On entering the estuary, colloids accounted for the dominant fraction of U to about a salinity of 1 psu, but only a minor fraction (<5%) at 3 psu. A substantial fraction of the total U is removed at <1 psu by Fe-organic rich colloids that aggregate and sink during initial estuarine mixing in the Kalix River estuary. In contrast, at salinities >1 psu, there is a general correlation between U and salinity in all filtered fractions. The 234U/238U ratios in different filtered fractions and sinking particles were generally indistinguishable at each station and showed enrichment in 234U, compared with secular equilibrium (δ234U = 266-567). This clearly shows that all size fractions are dominated by nondetrital U. Consideration of U isotope systematics across the estuary reveals that substantial U exchange must occur involving larger particles at least to 1 psu and involving colloids at least to ≈1.5 psu. Further exchange at higher salinities may also occur, as the proportion of U on colloids decreases with increasing salinity. This may be due to decreasing colloid concentration and increasing stabilization of uranyl carbonate complexes during mixing in the estuary. The results show that although U is a soluble element that shows generally conservative mixing in estuaries, removal occurs in the very low salinity zone, and this zone represents a significant sink of U. Variation in composition and concentration of colloidal particles between different estuaries might thus be an important factor for determining the varying behavior of U between estuaries.

  • 14. Andersson, Per S.
    et al.
    Wasserburg, Gerald J.
    Chen, J.H.
    Papanastassiou, D.A.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Element sources and transport in river and estuarine environments: isotopic studies in the Baltic Sea and its drainage basin1996In: Jubilee issue: short papers and abstracts for the Jubilee meeting "Current problems, ideas and results in geology" : Stockholm 16th-18th October 1996 at the celebration of the 125th anniversary of the Geological society of Sweden, Geologiska föreningen , 1996, p. 84-85Conference paper (Other academic)
  • 15.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Wasserburg, G.J.
    California Institute of Technology, Pasadena.
    Chen, J.H.
    California Institute of Technology, Pasadena.
    Papanastassiou, D.A.
    California Institute of Technology, Pasadena.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    238U234U and232Th230Th in the Baltic Sea and in river water1995In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 130, no 1-4, p. 217-234Article in journal (Refereed)
    Abstract [en]

    The concentration (C) of dissolved238U,234U,232Th and230Th in fresh and brackish waters from the Baltic Sea were determined using TIMS. The brackish waters range in salinity from that of sea water (SW) to 2.5‰. C238U in oxygen-saturated, surface waters is well correlated with salinity and shows quasi-conservative behavior, as does Sr. Samples from the redox water interface show depletion in C238U, demonstrating that dissolved U is being removed by FeMn oxyhydroxides. From a simple mixing relationship for the brackish water,δ234U* = 1000‰ was calculated for the fresh water source in the northern Baltic. A study of the Kalixälven River over an annual cycle yields highδ234U during spring and summer discharge and lower values during fall and winter, showing that different sources contribute to the U load in the river during different seasons. C232Th and C230Th in river water are governed by the discharge, reflecting the importance of the increased abundance of small particles ( < 0.45 μm) for the232Th230Th load at high discharge.232Th/238U in river water is about 40 times less than in detrital material. In the brackish water, C232Th drops 2 orders of magnitude in the low salinity region ( < 5‰), reaching a value close to that of sea water at a salinity of 7.5‰. Almost all of the riverine232Th must be deposited in the low-salinity regions of the estuary. The230Th/232Th in river waters is about twice the equilibrium value for232Th/238U (3.8). In the brackish waters,230Th/232Th is greater by a factor of 10-100 than both river water and SW. The big increase in230Th/232Th in the Baltic Sea waters over the riverine input indicates that the Th isotopes enter the estuary as a mixture of two carrier phases. We infer that about 96% of232Th in river water is carried by detrital particles, whereas the other phase (solution, colloidal) has a much higher232Th/232Th. Entering the estuary, the detrital particles sediment out rapidly, whereas the non-detrital phase is removed more slowly, causing a marked increase in230Th/232Th in the brackish water. In SW,230Th/232Th is closer to river input and detrital material than in brackish water. We conclude that in the deep sea,232Th is almost exclusively dominated by windblown dust and can be used to monitor dust flux. The230Th excess in Baltic rivers is produced in U-rich,232Th-poor peatlands and trapped in authigenic particles and transported with the particles. Time scales for producing the230Th excess are ≈ 2000-8000 yr. This is younger than, but comparable to, the time of the latest deglaciation, which ended some 9000 yr ago when the mires were forming. These results have implications for the possible mobility of actinides stored in repositories

  • 16. Andersson, Per S.
    et al.
    Wasserburg, G.J.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Isotopic and chemical composition of Sr and Nd in dissolved and suspended loads in fresh and brackish waters from the Baltic Sea1996In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 74, no 16, p. 329-Article in journal (Other academic)
  • 17.
    Andersson, Per S.
    et al.
    California Institute of Technology, Pasadena.
    Wasserburg, G.J.
    California Institute of Technology, Pasadena.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The sources and transport of Sr and Nd isotopes in the Baltic Sea1992In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 113, no 4, p. 459-472Article in journal (Refereed)
    Abstract [en]

    We have determined the concentration and isotopic composition of Sr and Nd in waters from the Baltic Sea. The Baltic Sea is an intracontinental, stratified, brackish water, estuarine-like system, and the rivers emptying into it drain a suite of terranes ranging from Proterozoic-Archean in the north to Phanerozoic in the south. The sampled brackish waters range in salinity from seawater (SW) at 35.289‰ to a minimum of 2.460‰ at the surface in the innermost part of the Gulf of Bothnia. The Sr concentrations show generally conservative behavior, indicating a simple two-component mixing. However, small deviations (3-70 ‰) from a perfect mixing line reveal that the imprints from rivers with different Sr concentrations are preserved in the blending. Strontium concentrations from a depth profile across the redoxcline in the Baltic proper indicate that vertical particle transport alters the Sr concentration in the water. Our estimated concentration of Sr in the average freshwater input to the Baltic is 0.03 ppm, which is only about 0.4% of the SW concentration. The Sr isotopic data range from εSr(SW) = 0 in seawater to εSrBW(SW) = 7.8 in the least saline Baltic water (BW) sample in the Gulf of Bothnia. The isotopic composition of Sr versus 1/Sr in the Baltic Sea follows an almost perfect mixing line, which shows that seawater Sr is mixed with much more radiogenic components. Calculated end-member values of εSr*(SW) for each sample show that the riverine input into the Gulf of Bothnia has εSr*(SW) = 120-200and10-50 ε units in the Baltic proper. These values are in general agreement with direct measurements of river waters in each region. However, the calculated values in the Gulf of Bothnia are lower than the measured river water input in this region, which indicates the presence of less radiogenic Sr, presumably originating from the river waters draining the southern part of the basin which are partially transported northward and mixed with Sr from the Gulf of Bothnia rivers. The Nd concentration in the Baltic Sea is not conservative, varying between 5 and 45 ppt, with the highest concentrations in the bottom waters due to vertical particulate transport. A plot of εNd(O) in Baltic water yields a good correlation with the calculated freshwater end member εSr*(SW). The data show that it is possible to unravel the different freshwater sources into the Baltic and to identify the zones of particulate removal of both non-conservative species such as the REE and of quasi-conservative species such as Sr. The use of isotopic tracers in this estuarine environment may provide a much better insight into mixing and element transport. It should also be possible to trace lateral movements of freshwater inputs

  • 18. Andersson, Per S.
    et al.
    Wasserburg, G.J.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Transport and mixing of Sr and Nd from old and young terranes in the Baltic Basin1992In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 73, no 14, p. 167-Article in journal (Other academic)
  • 19.
    Andersson, Per S.
    et al.
    California Institute of Technology, Pasadena.
    Wasserburg, G.J.
    California Institute of Technology, Pasadena.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stordal, Mary C.
    Texas A&M University at Galveston.
    Strontium, dissolved and particulate loads in fresh and brackish waters: the Baltic Sea and Mississippi delta1994In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 124, no 1-4, p. 195-210Article in journal (Refereed)
    Abstract [en]

    A study was conducted of the isotopic composition and concentration of Sr and of major elements in dissolved and suspended loads of fresh and brackish waters. The purpose was to establish the contributions of different parent rocks and minerals to Sr during weathering and transport and to identify the role of Fe_Mn oxyhydroxides in the redistribution of Sr in the water column during the sedimentary cycle. Studies were conducted on a profile across an oxic-anoxic boundary in the Baltic and on rivers covering behavior over an annual cycle. In general, the 87Sr/86Sr ratios differ between particulate and dissolved loads, with more radiogenic Sr in the particulate loads. These differences are attributed to differential weathering of minerals, where high Rb/Sr minerals dominate the particulate load and low Rb/Sr the dissolved load. There is broad correlation of 87Sr/86Sr with K/Al in the suspended load. The differences in 87Sr/86Sr between suspended and dissolved load are highly variable and are related to the Fe or Mn concentration on the particulates. In samples with high Fe/Al, the difference becomes small. A good correlation was found between Sr/Al and Fe/Al or Mn/Al in the particulates both in brackish and fresh waters. Sr is removed from solution both in rivers and in the Baltic Sea whenever there is formation of Fe_Mn oxyhydroxide particulates. This precipitation greatly diminishes the difference in isotopic composition of the dissolved and suspended loads. As the particles containing Fe_Mn oxyhydroxides settle, they dissolve in anoxic zones and release Sr. This provides a mechanism for Sr redistribution in the water column. Sr is thus only quasi-conservative in environments where Fe_Mn oxyhydroxides form or dissolve. From consideration of the isotopic differences in Sr between dissolved and suspended loads, it follows that the net Sr input depends upon weathering characteristics of the contributing mineral phases. Changes in weathering mechanisms due to climate change may cause Sr isotopic shifts in the marine environment.

  • 20.
    Andersson, Per
    et al.
    Stockholms Universitet.
    Torssander, P.
    Stockholms Universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sulphur isotope ratios in sulphate and oxygen isotopes in water from a small watershed in central Sweden1992In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 235-236, no 1, p. 205-217Article in journal (Refereed)
    Abstract [en]

    During 1988-89 water samples for sulphur and oxygen isotope measurements were collected in the Lake Mjösjön watershed (7.3 km2), central Sweden. Samples included: precipitation, throughfall, lakewater, shallow groundwater and inlet and outlet streams. The δ34S of sulphate in precipitation ranged from + 6.41‰ in winter to + 3.88‰ in summer, the higher winter values attributed to seasonal differences in the kinetic and equilibrium isotope fractionation during oxidation of atmospheric sulphur dioxide to sulphate. The δ34S in rain samples and in pine and spruce throughfall were similar, indicating no gain of sulphur from the trees. In the inflowing stream, the δ34S value increased as discharge decreased, from + 5.57‰ in spring to + 26.21‰ in summer, indicating bacterial sulphate reduction. The fluctuations in the inlet water were damped by the lake and in the outlet water, only a small decrease in the δ34S value during spring discharge was observed. During winter 1988-89, the near surface waters in the lake showed the same δ34S as snow indicating that meltwater governs the isotopic composition. During the winter, the δ34S in the near bottom waters increased while oxygen decreased due to bacterial sulphate reduction in the sediments. This also caused an increase in the alkalinity in the near bottom waters. Based on the δ18O data the water within the watershed is derived largely from meteoric water. During spring discharge, meltwater governs the inflow and outflow stream while additional groundwater influences occurred during the drier period. Most sulphur is derived from atmospheric deposition and the δ34S in sulphate increased during passage through the watershed due to bacterial sulphate reduction.

  • 21.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    High spatial resolution analysis of ferromanganese concretions by LA-ICP-MS2002In: Geochemical Transactions, ISSN 1467-4866, E-ISSN 1467-4866, Vol. 3, no 5, p. 40-47Article in journal (Refereed)
    Abstract [en]

    A procedure was developed for the determination of element distributions in cross-sections of ferromanganese concretions using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The effects of carrier flow rates, rf forward power, ablation energy, ablation spot size, repetition rate and number of shots per point on analyte intensity were studied. It is shown that different carrier gas flow rates are required in order to obtain maximum sensitivities for different groups of elements, thus complicating the optimisation of ICP parameters. On the contrary, LA parameters have very similar effects on almost all elements studied, thus providing a common optimum parameter set for the entire mass range. However, for selected LA parameters, the use of compromise conditions was necessary in order to compensate for relatively slow data acquisition by ICP-MS and maintain high spatial resolution without sacrificing the multielemental capabilities of the technique. Possible variations in ablation efficiency were corrected for mathematically using the sum of Fe and Mn intensities. Quantification by external calibration against matrix-matched standards was successfully used for more than 50 elements. These standards, in the form of pressed pellets (no binder), were prepared in-house using

  • 22.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilya
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Multielemental analysis of Mn-Fe nodules by ICP-MS: optimisation of analytical method2002In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 127, no 1, p. 76-82Article in journal (Refereed)
    Abstract [en]

    Two acid digestion procedures (microwave-assisted and room temperature) were developed for the quantitative analysis of ferromanganese nodules by inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS). Different compositions of the acid mixture, dilution factors and corrections for spectral interferences were tested. A combination of nitric, hydrochloric and hydrofluoric acids is necessary for complete sample digestion, with lowest acid to sample ratios (v/m) of 15 and 1.5. respectively, for the last two acids. Sample dilution factors higher than 2 X 104 should be used in order to decrease matrix effects and provide robust long-term instrumental operation. In spite of high dilution. method detection limits in the sub-mug g(-1) range were obtained for 54 out of 71 elements tested. due to the high detection capability of ICP-SFMS, as well as the special care taken to ensure the purity of reagents, to clean the instrument sample introduction system and to minimise sample handling. Owing to the presence of unresolved (at the resolution available) spectral interferences, accurate determination of Au, Hg, Os, Pd, Re and Rh is impossible without matrix separation. The accuracy of the entire analytical method was tested by the analysis of two nodule reference materials. The results generated agreed to within +/-2% for about 10, within +/-10% for more than 40 and within +/-20% for about 50 of 53 elements for which certified, recommended or literature values are available. A precision better than 3%, expressed as the between-digestion relative standard deviation (n=4). was obtained for the majority of elements, except in cases limited by low analyte concentrations

  • 23.
    Bauer, Susanne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Blomqvist, Sven
    Department of Ecology, Environment and Plant Sciences, Stockholm University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Distribution of dissolved and suspended particulate molybdenum, vanadium, and tungsten in the Baltic Sea2017In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 196, p. 135-147Article in journal (Refereed)
    Abstract [en]

    In natural waters, dissolved oxyanions often dominate over the particle-bound element fraction. Still, the scavenging of oxyanions by suspended particles might contribute significantly to their dynamic cycling and distribution. To investigate how oxyanions are affected by manganese (Mn) redox cycling, detailed depth profiles across the pelagic redox zone at the Landsort Deep, Baltic Sea, were collected for molybdenum (Mo), vanadium (V), and tungsten (W), for both dissolved (<0.22 µm) and suspended particulate (>0.22 µm) fractions.

    All three oxyanions show a non-conservative behavior in the stratified Landsort Deep. Strong linear correlations with Mn in the particulate fraction in the redox zone of the Landsort Deep suggest that Mn redox cycling influences their distribution. In the dissolved fraction, Mo, V, and W exhibited rather different behavior. Molybdenum was depleted below the redox zone, while V was depleted only within the redox zone. Tungsten concentrations increased within the redox zone, being three times higher in the sulfidic zone than in the surface water. Unlike Mo, W shows no tendency for adsorption or co-precipitation under the prevailing weak sulfidic conditions in the deep water of the Landsort Deep and is, therefore, not exported to the underlying sediment.

    The Landsort Deep data were compared with data from the northern Baltic Sea (Bothnian Bay, Kalix River and Råne River estuaries), where particulate iron (Fe) occurs in high abundance. The particulate fractions of Mo, V, and W decreased during mixing in these estuaries. Vanadium showed the most drastic reduction, with a decrease in dissolved and particulate fractions, indicating that different processes influence the distribution of these oxyanions.

  • 24.
    Bauer, Susanne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Conrad, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry of tungsten and molybdenum during freshwater transport and estuarine mixing2018In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 93, p. 36-48Article in journal (Refereed)
    Abstract [en]

    The geochemistry of tungsten (W) in the environment is poorly studied. Tungsten usually occurs in low concentrations in natural waters and is not very mobile. For this study, we analyzed W together with molybdenum (Mo) in the dissolved and particulate fractions of two boreal estuaries during different seasons. Additionally, we sampled first-order streams that drain different landscape types and the receiving northern Baltic Sea. Furthermore, surface sediment from the estuaries was analyzed to obtain a comprehensive overview of the distribution of W and Mo in a boreal environment.

    Both elements showed different distribution patterns during different seasons. While they decreased in the dissolved fraction during spring discharge, in winter, their concentrations were elevated. Molybdenum exhibited non-conservative behavior along the salinity gradient in winter, which was probably caused by its release from underlying sediments. In the particulate fraction, we found opposite behaviors for Mo and W, with higher particulate W and lower particulate Mo during spring discharge.

    Molybdenum and W underwent fractionation from land to sea, indicating the different mobilities of these oxyanions. The Mo/W ratio in the dissolved fraction was mainly determined by the Mo concentration, as the W concentration varied only in a narrow range from first-order streams to the Bothnian Bay. In the particulate fraction, the Mo/W ratio appeared to be affected by scavenging processes and showed only small variations.

  • 25.
    Bauer, Susanne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Conrad, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The geochemistry of tungsten in the Baltic Sea2015Conference paper (Other academic)
  • 26.
    Bauer, Susanne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Role of Mn for cycling of oxyanions (Mo, V and W) across the pelagic redox zone, Landsort Deep2015Conference paper (Other academic)
    Abstract [en]

    The Landsort Deep in the Baltic Sea is a stratified basin with a pelagic redox zone separating the oxic water from the sulphidic water below. In this zone redox cycling of Mn plays an important role for the distribution of trace elements. Freshly formed Mn oxide acts as carrier for trace elements across the redox zone. In the underlying sulphidic zone the adsorbed trace elements are released when Mn is reduced and the Mn particles dissolve. Mn oxide has a negative surface charge at seawater pH conditions. Oxyanions would most likely adsorb on Fe oxides instead of Mn oxide due to the surface charge. The particulate Fe concentration in the redox zone of the Landsort Deep is 10-40 times lower than the concentration of particulate Mn. Therefore the Landsort Deep is an excellent place to study the role of Mn for cycling of oxyanions. This study shows uptake of Mo, V and W on Mn particles in the redox zone. Insights from this study may also be applicable for other oxyanion forming elements as P. The Landsort Deep in the Baltic Sea was sampled over a two-year period. Detailed profiles for the dissolved (<0.22 m) and particulate (>0.22 m) fraction were taken across the pelagic redox zone. While the pattern of dissolved Mn is constant during the sampling period maxima for particulate Mn vary in concentration and depth. Throughout the sampling period Mo, V and W are following Mn in the particulate fraction within the redox zone.

  • 27.
    Bauer, Susanne
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Älvtransporterade spårmetaller till Bottenviken: Genomgång av monitoringdata2012Report (Other academic)
    Abstract [sv]

    Data visar att det är svårt att karakterisera och ta fram en ”typ-älv” för spårmetalltransportentill Bottenviken. Det är stora skillnader i transporten av spårmetaller mellan kustnära vattendrag,som dränerar sediment som tidigare avsatts i Bottenviken, skogsälvar och fjällälvar. Dessutom ärskillnaderna stora mellan älvar av samma typ. Trots att Kalixälv och Torneälv dränerar samma typav berggrund och lösa avlagringar är kemin olika för flera spårmetaller. Skillnaderna är i grundenberoende på vittringsförhållanden i dräneringsområdet och vattenföringen, men späds på av analyssvårigheteroch avsaknaden av filtrerade prov.I stort sett visar järn, krom, aluminium och totalt organiskt kol liknade mönster, även om de iblandinte är korrelerade i varje älv. Zink, kadmium, kobolt och nickel är korrelerade till mangan, meni flera älvar är inte sambandet uppenbart. Arsenik är linjärt korrelerat till järn söder om Piteälven.Halterna av järn är låga i utbyggda älvar, vilket indikerar att järntransporten minskar när en älvbyggs ut. Zinkvärdena i monitoringdata verkar vara påverkade av kontamination. De flesta kadmiumvärdenligger nära detektionsgränsen och överlag är kadmiumhalterna inte tillförlitliga.Övervakningsprogrammet bygger på ofiltrerade syrasatta vattenprov. Problemet med sådana provär att analysvärdena ”hoppar”. Syrasättningen löser inte upp bergartsfragment men löser järnmanganoxidhydroxidpartiklar.Partiklar påverkar med andra ord analysen på ett oregelbundet sätteftersom mängden, och typen a partiklar, varierar kraftigt speciellt vid höga flöden.Proven bör filtreras i fält, enklast genom sprutfiltrering. Filtren kan sparas för analys eller baralagras. Oberoende om filtren analyseras eller inte blir den lösta fraktionen bättre definierad än utanfiltrering. Filtrering förändrar inte nämnvärt provtagningskostnaden och analyskostnaden blir densamma (utan filteranalys). Filtrering bör införas omgående. För att kunna jämföra med tidigare årbör både ofiltrerad och filtrerad fas analyseras under ett eller två år.I vissa system bör även den partikulära fasen bestämmas. Detta är speciellt viktigt för att förståförändringar i järn och mangantransporten, eftersom dessa grundämnen styr flera spårmetaller ochfosfor. Brunifieringen av svenska vattendrag är tydlig i flera större och mindre vattendrag. Brunifieringenberor på förhöjda halter av bla. järn och mangan. För att förstå orsakerna till brunifieringmåste både filtrerade prov och partiklar analyseras.Markanvändning och dess betydelse för transporten av järn och mangan är en viktig forskningsfråga.Dels för att det finns gränsvärden uppsatta för säker mänsklig konsumtion, dels för attdessa grundämnen styr biotillgängligheten av fosfor i Östersjön, via en serie av komplicerade biogeokemiskaprocesser. Detaljerade kunskaper, på molekylnivå, om järn-mangan oxidhydroxideroch deras biogeokemi är viktig.Eftersom det är järn-mangan oxidhydroxider som till stor del reglerar utbytet mellan vatten ochsediment blir tillgången av dessa grundämnen central. Källorna för både järn och mangan är påland. Hanteringen av markfrågor kan med andra ord direkt påverka tillflödet av järn och mangan.Kopplingen mellan marktyp-markanvändning och utflödet av järn och mangan är idag litestuderat. Fosfortransporten i sötvatteninflödet är också starkt korrelerad till järnoxidhydroxider.Biotillgängligheten av den tillförda fosforn är lite studerat. Nya data antyder att fosforn inte ärdirekt biotillgänglig. Detta kan bero på ett komplext samspel mellan fosfor-järn-fotoreduktion, enkoppling som inte studerats i Östersjön.2Höga halter fosfor sitter bundet i ytsediment i Bottniska viken. En sänkning av redoxnivån skullefrigöra fosforn och systemet skulle snabbt bli eutroft. Tröskelvärdet för hur mycket näringsämnensom kan tillföras utan att förändra syreförhållandena är okänt. Bottenhavet och Bottenvikenär idag viktiga sänkor för fosfor. Hur stabila dessa sänkor är för miljöförändringar blir därför enviktig fråga. Eftersom Bottenhavet i stort sett saknar Mn-barriären så är denna bassäng troligenkänsligare för förändringar jämfört med Bottenviken.Kadmium visar en stigande trend i sedimentdata från Bottenviken. Inga andra metaller, förutombly, visar en sådan klar förändring. Orsaken till förändringen kan bero på landhöjningen (exponeringav sulfidleror på land) och oligotrofieringen av Bottenviken, men mekanismen är inte klarlagdoch bör studeras i detalj.

  • 28. Boström, Kurt
    et al.
    Burman, J-O
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pontér, Christer
    Accumulation and selective loss patterns for Mn, Ba and other trace metals in the Baltic Sea1983In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 64, no 18, p. 243-Article in journal (Other academic)
  • 29. Boström, Kurt
    et al.
    Burman, J-O
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pontér, Christer
    Accumulation and selective loss patterns for Mn, Ba and other trace metals in the Baltic Sea1984In: Abstracts: 16e Nordiska geologiska vintermötet, Stockholm 9-13 januari 1984 / [ed] G. Armands; S. Schager, Stockholm: Stockholm: Institutionen för musik- och teatervetenskap, Stockholms universitet, 1984, p. 33-Conference paper (Other academic)
  • 30.
    Boström, Kurt
    et al.
    Luleå tekniska universitet.
    Burman, J-O
    Luleå tekniska universitet.
    Pontér, Christer
    Luleå tekniska universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Selective removal of trace elements from the Baltic by suspended matter1981In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 10, no 4, p. 335-354Article in journal (Refereed)
    Abstract [en]

    Suspended matter was collected at 30 stations in the Baltic and Kattegatt, at the thermocline and at the bottom, and analysed for Na, Ca, Mg, Si, Ti, Al, Fe, Mn, Ba, Sr, Ni and V. The composition of the suspended matter varies considerably, but can be described as a mixture of: (1) 12-25% terrigenous detritus with much Si, Al, Ti and Fe; (2) 75-88% biological matter with much Ni, V and Ba; and (3) some Mn-oxyhydroxide.The annual efflux of water from the Baltic is about 460 km3, with a suspended load in the Baltic straits of 1.2-3.6 mg ash material l-1 These values imply that much Si, Ti, Al, Fe, Sr, Ni and V and particularly much Ba and Mn are lost from the Baltic in the suspended load.The average suspended matter is richer in Mn(5×), Ba(2.5×), Sr(4×) and V(1.8×) than permanently depositing Baltic sediments. These constituents are relatively enriched in pelagic deposits, i.e. it is likely that much Mn, Ba and V in deep-sea sediments derive from the continents via suspended transport. This conclusion is supported by the similarity between suspended matter and average Atlantic pelagic sediment.

  • 31.
    Boström, Kurt
    et al.
    Stockholms Universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Boström, B.
    Andersson, Per
    Arvantides, N.
    Galanopoulos, V.P.
    Kalogeropoulos, S.
    Papavassiliou, C.
    Paritsis, S.
    Chemistry of hydrothermal solutions in drill hole GPK-1, Palaea Kameni, Santorini, Greece1990In: Thera and the Aegean world, III: proceedings of the third international congress, Santorini, Greece, 3-9 September 1989. Vol. 2, Earth sciences / [ed] David A. Hardy; Kurt Boström, The Thera Foundation , 1990, Vol. 3, p. 257-260Conference paper (Refereed)
  • 32.
    Boström, Kurt
    et al.
    Stockholms Universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Boström, B.
    Andersson, Per
    Löfvendahl, R.
    Metallogenesis at Santorini: a subduction-zone related process; II, Geochemistry and origin of hydrothermal solutions on Nea Kameni, Santorini, Greece1990In: Thera and the Aegean world, III: proceedings of the third international congress, Santorini, Greece, 3-9 September 1989. Vol. 2, Earth sciences / [ed] David A. Hardy; Kurt Boström, The Thera Foundation , 1990, Vol. 3, p. 291-299Conference paper (Refereed)
  • 33.
    Boström, Kurt
    et al.
    Stockholms Universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pontér, Christer
    Luleå tekniska universitet.
    Origin of iron-manganese-rich suspended matter in the Landsort Deep, NW Baltic Sea1988In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 24, no 1, p. 93-98Article in journal (Refereed)
    Abstract [en]

    Water sampling was undertaken in 1982 in the Landsort Deep, NW Baltic Sea, at eight depth levels. In the 0-150 m interval oxidizing conditions prevailed, with suspended phases being particularly rich in Fe (with a maximum at 150 m), Mn and Ba (with maxima at 100 m). The anoxic zone below 150 m showed high concentrations of dissolved Fe and particularly dissolved Mn which were much higher than in the Black Sea, for instance. This is probably due to the migratory behavior of the redoxcline in the Landsort Deep. The metal-rich suspended matter probably arises when dissolved Fe and Mn from the anoxic zone precipitate as hydroxyoxides at the redoxcline; lateral transport of such suspended matter may explain the large-scale selective loss of Mn and Ba from the Baltic basin.

  • 34.
    Boström, Kurt
    et al.
    Stockholms Universitet.
    Perissoratis, C.
    Galanopoulos, V.
    Papavassiliou, C.
    Boström, B.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kalogeropoulos, S.
    Geochemistry and structural control of hydrothermal sediments and new hot springs in the caldera of Santorini, Greece1990In: Thera and the Aegean world, III: proceedings of the third international congress, Santorini, Greece, 3-9 September 1989. Vol. 2, Earth sciences / [ed] David A. Hardy; Kurt Boström, The Thera Foundation , 1990, Vol. 3, p. 325-336Conference paper (Refereed)
  • 35.
    Boström, Kurt
    et al.
    Luleå tekniska universitet.
    Wiborg, Lars
    Luleå tekniska universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemistry and origin of ferromanganese concretions in the Gulf of Bothnia1982In: Marine Geology, ISSN 0025-3227, E-ISSN 1872-6151, Vol. 50, no 1-2, p. 1-24Article in journal (Refereed)
    Abstract [en]

    Ferromanganese concretions cover large areas of the Gulf of Bothnia. They are flat to well-rounded, the rounded ones being richer in oxyhydroxides of iron and manganese. Rounded and ellipsoidal nodules, particularly those in the northern Gulf of Bothnia, are richest in Mn, Ni, Ba and Cu, which probably coexist in a Mn oxyhydroxide phase. Flat nodules are enriched in Fe, P, rare earths and As, probably associated with an Fe oxy-hydroxide component. Aluminum, V, Cr and Ti occur in still another phase. The sediments of the gulf generally consist of a 10-50 mm-thick layer of oxidized surface sediment, enriched in Mn, Ba, P and Ni lying on top of reduced sediments which are diagenetically depleted in these elements. The remobilized elements have redeposited in the nodules, but this process cannot explain the origin of all the nodular material. Some released Mn, Ba and Ni furthermore enter into suspended phases, which eventually leave the Baltic Sea. The economic value of the nodules in the Gulf of Bothnia is probably limited at present.

  • 36.
    Breitbarth, E.
    et al.
    Department of Chemistry, University of Otago, Dunedin.
    Achterberg, E.P.
    National Oceanography Center Southampton, University of Southampton.
    Ardelan, M.V.
    Norwegian University of Science and Technology, Department of Chemistry, Trondheim.
    Baker, A.R.
    School of Environmental Sciences, University of East Anglia, Norwich.
    Buccarelli, E.
    Université Européenne de Bretagne.
    Chever, F.
    Université Européenne de Bretagne.
    Croot, P.L.
    IFM-GEOMAR, Leibniz-Institute of Marine Sciences, Division Marine Biogeochemistry, Kiel.
    Duggen, S.
    IFM-GEOMAR, Leibniz-Institute of Marine Sciences, Division Dynamics of the Ocean Floor, Kiel.
    Gledhill, M.
    National Oceanography Center Southampton, University of Southampton.
    Hassellöv, Martin
    University of Gothenburg.
    Hassler, C.
    Centre for Australian Weather and Climate Research (CAWCR), Hobart.
    Hoffmann, L.J.
    Department of Chemistry, University of Otago, Dunedin.
    Hunter, K.A.
    Department of Chemistry, University of Otago, Dunedin.
    Hutchins, D.A.
    Department of Biological Sciences, University of Southern California, Los Angeles.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Jickells, T.
    School of Environmental Sciences, University of East Anglia, Norwich.
    Lohan, M.C.
    Marine Institute, University of Plymouth.
    Nielsdóttir, M.C.
    National Oceanography Center Southampton, University of Southampton.
    Sarthou, G.
    Université Européenne de Bretagne.
    Schoemann, V.
    Ecologie des Systémes Aquatiques, Université Libre de Bruxelles.
    Trapp, J.M.
    University of Miami, Rosenstiel School of Marine and Atmospheric Science, Department of Marine and Atmospheric Chemistry, Miami.
    Turner, D.R.
    Department of Chemistry, University of Gothenburg.
    Ye, Y.
    Alfred Wegener Institute for Polar and Marine Research, Bremerhaven.
    Iron biogeochemistry across marine systems: progress from the past decade2010In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 7, no 3, p. 1075-1097Article in journal (Refereed)
    Abstract [en]

    Based on an international workshop (Gothenburg, 14-16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas

  • 37.
    Breitbarth, Eike
    et al.
    Department of Chemistry, University of Otago, Dunedin.
    Gelting, Johan
    Walve, Jakob
    Department of Systems Ecology, Stockholm University.
    Hoffmann, Linn
    Department of Chemistry, University of Otago, Dunedin.
    Turner, David
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Hassellöv, Martin
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Dissolved iron (II) in the Baltic Sea surface water and implications for cyanobacterial bloom development2009In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 6, no Special issue, p. 2397-2420Article in journal (Refereed)
    Abstract [en]

    Iron chemistry measurements were conducted during summer 2007 at two distinct locations in the Baltic Sea (Gotland Deep and Landsort Deep) to evaluate the role of iron for cyanobacterial bloom development in these estuarine waters. Depth profiles of Fe(II) were measured by chemiluminescent flow injection analysis (CL-FIA). Up to 0.9 nmol Fe(II) L−1 were detected in light penetrated surface waters, which constitutes up to 20% to the dissolved Fe pool. This bioavailable iron source is a major contributor to the Fe requirements of Baltic Sea phytoplankton and apparently plays a major role for cyanobacterial bloom development during our study. Measured Fe(II) half life times in oxygenated water exceed predicted values and indicate organic Fe(II) complexation. Potential sources for Fe(II) ligands, including rainwater, are discussed. Fe(II) concentrations of up to 1.44 nmol L−1 were detected at water depths below the euphotic zone, but above the oxic anoxic interface. Mixed layer depths after strong wind events are not deep enough in summer time to penetrate the oxic-anoxic boundary layer. However, Fe(II) from anoxic bottom water may enter the sub-oxic zone via diapycnal mixing and diffusion.

  • 38. Chen, J.H.
    et al.
    Andersson, Per S.
    Wasserburg, G.J.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Uranium geochemistry in the Baltic Sea: mixing of different sources deduced from 234U - 238U1993In: EOS: Transactions, ISSN 0096-3941, E-ISSN 2324-9250, Vol. 74, no 16, p. 329-Article in journal (Other academic)
  • 39.
    Conrad, Sarah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Enrichment of heavy iron isotopes in suspended matter during estuarine mixing2015Conference paper (Other academic)
  • 40.
    Conrad, Sarah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fe-OC aggregates from headwaters to the estuary: The story of Fe-isotopes2016Conference paper (Refereed)
  • 41.
    Conrad, Sarah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Iron isotope signatures in low salinity estuaries, northern Baltic Sea2014Conference paper (Refereed)
  • 42. Dahlqvist, R.
    et al.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Behaviour of Ca during ultrafiltration of river water2002In: Vol. 66, no 15, Suppl. 1Article in journal (Refereed)
  • 43.
    Dahlqvist, Ralf
    et al.
    Department of Geology and Geochemistry, Stockholm University.
    Andersson, Karin
    Marine Chemistry, Department of Chemistry, Göteborg University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Larsson, Tobias
    Marine Chemistry, Department of Chemistry, Göteborg University.
    Stolpe, Björn
    Marine Chemistry, Department of Chemistry, Göteborg University.
    Turner, David
    Marine Chemistry, Department of Chemistry, Göteborg University.
    Temporal variations of colloidal carrier phases and associated trace elements in a boreal river2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 22, p. 5339-5354Article in journal (Refereed)
    Abstract [en]

    Elemental size distributions, from truly dissolved through colloidal to particulate, have been studied in a subarctic boreal river. The measurements, carried out during 2002, ranged from winter to summer conditions, including an intense spring flood event. Results are reported for a total of 42 elements. Size distributions were characterised using a combination of cross-flow (ultra)filtration (CFF), flow field-flow fractionation (FlFFF), and diffusive gradients in thin-films (DGT). The three techniques showed similar trends, but quantitative comparisons reveal some important differences that warrant further investigation.

  • 44.
    Dahlqvist, Ralf
    et al.
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Andersson, Per S.
    Luleå tekniska universitet.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The concentration and isotopic composition of diffusible Nd in fresh and marine waters2005In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 233, no 1-2, p. 9-16Article in journal (Refereed)
    Abstract [en]

    Variations in the Nd isotopic composition of ocean water through time, recorded in marine deposits, are suggested to document changes in erosional input and ocean circulation. Thus characterization of the dissolved Nd component in seawater is important. But few attempts have been made to directly measure truly dissolved Nd. Here we report Nd data, obtained using the technique of diffusive gradients in thin-films (DGT) designed to measure in situ, diffusible labile trace metals in aqueous solutions. The method samples free ions and possibly very small complexes. The concentration and isotopic composition of Nd in fresh, brackish and seawater have been determined with DGT, analyzed with thermal ionization mass-spectrometry, and compared with filtered and bulk water samples. Concentrations measured in water samples and with DGT show that the relative amount of diffusible Nd increases with salinity, from being about 10% in the fresh water to 42% in seawater. At each sampled site, the isotopic composition of Nd in the water shows a similar isotopic composition, within errors, with Nd sampled using the DGT method. These results indicate that there is a complete exchange between the particulate/colloidal fraction and the truly dissolved phase. Therefore our findings suggest that solute Nd reflects both the isotopic composition of the marine sediments and the bulk water.

  • 45. Dahlqvist, Ralf
    et al.
    Andersson, Per S.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The neodymium-isotopic composition in a boreal river: a reflection of selective weathering and colloidal transport1999In: Ninth annual V. M. Goldschmidt conference, 1999, p. 66-Conference paper (Other academic)
  • 46.
    Dahlqvist, Ralf
    et al.
    University of Oxford.
    Andersson, Per S.
    Swedish Museum of Natural History.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Porcelli, D.
    University of Oxford.
    Vertical REE profiles in water and DGT in the central Arctic Ocean2006In: Vol. 70, no 18S, p. A125-Article in journal (Other academic)
  • 47.
    Dahlqvist, Ralf
    et al.
    Department of Geology and Geochemistry, Stockholm University.
    Benedetti, Marc F.
    Laboratorie de Géochimie et Métallogénie, Universite Pierre et Marie Curie, Paris.
    Andersson, Karen
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Turner, David
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Larsson, Tobias
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Stolpe, Björn
    Department of Chemistry, Analytical and Marine Chemistry, Göteborg University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Association of calcium with colloidal particles and speciation of calcium in the Kalix and Amazon rivers2004In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 68, no 20, p. 4059-4075Article in journal (Refereed)
    Abstract [en]

    A considerable amount of colloidally bound Ca has been detected in water samples from Amazonian rivers and the Kalix River, a sub-arctic boreal river. Fractionation experiments using several analytical techniques and processing tools were conducted in order to elucidate the matter. Results show that on average 84% of the total Ca concentration is present as free Ca. Particulate, colloidal and complexed Ca constitute the remaining 16%, of which the colloidal fraction is significant. Ultrafiltration experiments show that the colloidal fraction in the sampled Amazonian rivers and the Kalix River range between 1% and 25%. In both the Amazonian and the Kalix rivers the technique of cross-flow ultrafiltration was used to isolate particles and colloids. The difference in concentration measured with ICP-AES and a Ca ion-selective electrode in identical samples was used to define the free Ca concentration and thus indirectly the magnitude of the particulate, colloidal and complexed fractions. Results from the Kalix and Amazonian rivers are in excellent agreement. Furthermore, the results show that the colloidal concentrations of Ca can be greatly overestimated (up to 227%) when conventional analysis and calculation of ultrafiltration data is used due to retention of free Ca ions during the ultrafiltration process. Calculation methods for colloidal matter are presented in this work, using complementary data from ISE analysis. In the Kalix River temporal changes in the fractionation of Ca were studied before, during and after a spring-flood event. Changes in the size distribution of colloidally associated Ca was studied using FlFFF (Flow Field-Flow Fractionation) coupled on-line to a HR ICP-MS. The FlFFF–HR ICP-MS fractograms clearly show the colloidal component of Ca, supporting the ultrafiltration findings. During winter conditions the size distribution of colloidally associated Ca has a concentration maximum at 5 to 10 nm in diameter, shifting to smaller sizes (<5 nm) during and after the spring flood. This shift in size distribution follows a change in the river during this period from ironoxyhydroxy colloids being the most important colloidal carrier phase to humic substances during and after the spring flood. WHAM and NICA-Donnan models were used to calculate the amount of colloidally bound Ca. The results similar for both models, show that on average 16% of the Ca may be associated to a colloidal phase, which is in broad agreement with the measurements.

  • 48.
    Dahlqvist, Ralf
    et al.
    Stockholm University.
    Zang, Hao
    Lancaster University.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Davidson, William
    Stockholm University.
    Performance of the diffusive gradients in thin films technique for measuring Ca and Mg in freshwater2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 460, no 2Article in journal (Refereed)
    Abstract [en]

    Measurements of the major cations Ca and Mg by the technique of diffusive gradients in thin films (DGTs) were systematically evaluated. The concentration in solution was calculated using Fick's first law of diffusion from the directly measured flux to the DGT device. A selective cation exchange resin (Bio-Rad Chelex®100), which has been used extensively with DGT for trace metals, such as Cd2+, Cu2+ and Ni2+, was used for this work. Elution of Ca and Mg from the resin with 1 M HNO3 was very reproducible. Measurements of Ca and Mg concentrations in synthetic solutions agreed well with the theoretical predictions. The negative response on uptake caused by lowered pH was investigated. Uptake was found to decline below pH 5. The capacity of the DGT device for Ca and Mg was also investigated to establish maximum deployment times for given concentrations. Experiments with filtered and modified lake water show that DGT can be used to measure Ca and Mg when trace metals are present in the solution. An in situ deployment of DGT combined with an ultrafiltration study suggest that the Mg concentration measured by DGT is similar to the concentration found in the fraction <1 kDa.

  • 49.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    Characterization of the silicon isotopic composition of the terrestrial biogenic output from a boreal forest in Northern Sweden2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 15s, p. A256-Article in journal (Other academic)
    Abstract [en]

    During the last decade, the potential plant impact on the biogeochemical cycle of Si via the large terrestrial biogenic Si reservoir formed by vegetation has attracted considerable interest. It has been concluded that the release of silicic acid from dissolution of soil phytoliths might exceed the Si mobilized by weathering of Si-containing primary minerals, which implies that the biogenic contribution to the total content of Si in the soil profile must be considered in weathering studies. Information about Si isotopes can potentially be used for differentiation between relative contributions from biogenic and mineral sources in natural waters, soil solutions and plants. This would, however, require thorough characterization of the terrestrial biogenic Si reservoir, a task that received somewhat limited attention to date. The aim of the present study was to characterize the Si isotopic composition of a boreal forest, with bedrock consisting of dolomitic limestone, in Northern Sweden. Representative biomass from the forest area exhibited a surprisingly homogenous Si isotopic composition, ranging from δ29Si (-0.14 ± 0.05)‰ (2σ) to (0.13 ± 0.04)‰. Further, a change in the Si isotopic composition of (+0.39 ± 0.04)‰ has been detected in Leymus arenarius, indicating predominant accumulation of heavier isotopes from spring to autumn. Recent studies of Si isotopic composition in plants have been focused on the root uptake of dissolved silicic acid as the only Si accumulation path. Results acquired during the present study provide compelling evidence to suggest that exogenous Si is also incorporated in the surface structure of the plant material. A surface contribution in excess of 5% of the total Si would introduce a significant shift in the bulk isotopic composition (>0.1‰) assuming that the exogenous material differed by 2‰ from the biogenic Si. This strongly suggests that the surface contribution must be carefully considered during in situ uptake studies.

  • 50. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Baxter, Douglas
    Ecke, Frauke
    Österlund, Helene
    Öhlander, Björn
    Temporal isotopic variations of dissolved silicon in a pristine boreal river2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A333-Article in journal (Other academic)
    Abstract [en]

    Interest in quantifying the biogenic impact on the terrestrial biogeochemical Si cycle has increased significantly since biological control has been suggested. Previous observations of isotopic fractionation of Si during biogeochemical and geochemical processes imply that seasonal dissolved Si isotopic patterns in rivers have the potential for use in extracting information about the riverineand terrestrial biogeochemical Si cycles.Therefore, variations in the isotopic composition of dissolved riverine Si were investigated for the Kalix River, Northern Sweden, one of the largest pristine rivers in Europe, based on high-frequency sampling during a period of 25 weeks from early April to early October 2006. Temporal variations spanning 0.4. for δ29Si and 0.8. for δ30Si of dissolved Si in the Kalix River were observed during the period, suggesting that the riverine Si input to the oceans cannot be considered to have a constant Si isotopic composition even on a short time scale. The results implicate biogeochemical Si-cycling via formation and dissolution of biogenic silica as major processes controlling the Si transport in boreal systems. The Si budget in the river system appeared to be controlled by relative Si accretions during high discharge events and relative Si depletions in the subarctic mountainous and lake dominated areas. There were also temporal variations in Si isotopic composition with accretion (relative Si contribution), accompanied by depletion of the heavier Si isotopes, while the opposite trend was observed during periods of riverine Si depletion. These isotope variations can be explained by release of plant derived silica, depleted in heavier Si isotopes, during the spring snowmelt. Further, increased volumetric contribution from the headwater and losses of Si due to biogenic silica formation by diatoms in the subarctic lakes at a later period are expected to be responsible for the preferential losses of lighter isotopes. These conclusions are further verified by land cover analysis.

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