News Archive
New study on Hg isotopes in contaminated sediments reveals distinct "isotopic fingerprints" for sites polluted by different industrial sources in Sweden.
December 1, 2014
Wiederhold, J., Skyllberg, U., Drott, A., Jiskra, M., Jonsson, S., Björn, E., Bourdon, B., and Kretzschmar, R. (2015): Mercury isotope signatures in contaminated sediments as tracer for local industrial pollution sources. Environ. Sci. Tech. 49, 177-185.
Congratulations Katrin!
December 2, 2014
Congratulations to Katrin on receiving the 2014 Soil & Environmental Quality Graduate Student Award, sponsored by the Soils & Environmental Quality Division of the Soil Science Society of America, for her work on the 'Impact of Birnessite on Arsenic and Iron Speciation during Microbial Reduction of Arsenic-Bearing Ferrihydrite'.
Creek sediments downstream of a former Hg mine provide a more reliable Hg isotope mining source signature for tracing studies than the highly heterogeneous site point sources.
December 11, 2014
Smith, R., Wiederhold, J., Jew, A., Brown, G., Bourdon, B., and Kretzschmar, R. (2015): Stable Hg isotope signatures in creek sediments impacted by a former Hg mine. Environ. Sci. Tech. 49, 767-776.
Congratulations Robin!
December 18, 2015
Robin Smith is our newest PhD after defending her thesis "Mercury stable isotope fractionation in mining environments and its implications for using Hg isotopes as a source tracer" today. She is pictured here wearing her soil chemistry doctoral hat with examiners (from L to R) Prof. H. Biester (TU Braunschweig), Dr. Jan Wiederhold (ETH Zürich), Prof. R. Kretzschmar (ETH Zurich), and Prof. B. Bourdon (ENS Lyon).
Review article in ES&T introduces the emerging research field of metal stable isotopes and their application as source and process tracers in environmental geochemistry.
February 2, 2015
Wiederhold, J. (in press): Metal stable isotope signatures as tracers in environmental geochemistry. Environ. Sci. Tech. (Accepted).
Welcome Jeff!
February 2, 2015
external pageProf. Jeff Catalano from the Department of Earth and Planetary Sciences at Washington University in Saint Louis, Missouri, USA joined us as a guest professor for a 6-month sabbatical.
Congratulations Tinu!
October 31, 2014
Martin 'Tinu' Jiskra defended his PhD thesis "Terrestrial Mercury Cycling Investigated with Stable Mercury Isotopes" today. He is pictured here in his soil chemistry doctoral hat with examiners (from L to R) Prof. B. Bourdon (ENS Lyon), Dr. Jan Wiederhold (ETH Zürich), Dr. Jeroen Sonke (CNRS Toulouse) and Prof. R. Kretzschmar (ETH Zurich).
In-vitro gastrointestinal extractions of highly As-contaminated floodplain soils reveal that As bioaccessibility is controlled by the slow dissolution kinetics of As(V)-bearing ferrihydrite and the formation of As(V)-rich HFO in the gastric environment.
October 30, 2014
Mikutta, C., Mandaliev, P., Mahler, N., Kotsev, T., and Kretzschmar, R. (2014): Bioaccessibility of Arsenic in Mining-Impacted Circumneutral River Floodplain Soils. Environ. Sci. Tech. 48: 13468-13477.
Study of natural Fe-rich flocs reveals elevated trace element contents and arsenate binding to floc Fe(III)-(oxyhydr)oxides.
October 27, 2014
ThomasArrigo, L., Mikutta, C., Byrne, J., Barmettler, K., Kappler, A., and Kretzschmar, R. (2014): Iron and Arsenic Speciation and Distribution in Organic Flocs from Streambeds of an Arsenic-enriched Peatland. Environ. Sci. Tech. 48: 13218-13228.
Isotope exchange experiments revealed slow and incomplete exchange of Hg(II) bound to natural organic matter and goethite.
October 3, 2014
Jiskra, M., Saile, D., Wiederhold, J., Bourdon, B., Björn, E., and Kretzschmar, R. (2014): Kinetics of Hg(II) Exchange between Organic Ligands, Goethite, and Natural Organic Matter Studied with an Enriched Stable Isotope Approach. Environ. Sci. Tech. 48: 13207-13217.
Hiking day 2014
September 25, 2014
This year's soil chemistry hikers (Zoey, Robin, Jan, Iso, Laurel, Christian, Tinu, Kurt, Ruben, and Katrin) had a great day hiking through 'Glarnerland' to Nüenchamm and the Talalpsee. Late afternoon sunshine and beautiful views of the Walensee were enjoyed at an evening BBQ.
New laboratory study reveals that the ability of Mn oxides to oxidize As(III) is limited by the rapid oxidation of Fe(II) under microbially reducing conditions.
September 22, 2014
Ehlert, K., Mikutta, C., and Kretzschmar, R. (2014): Impact of Birnessite on Arsenic and Iron Speciation during Microbial Reduction of Arsenic-Bearing Ferrihydrite. Environ. Sci. Tech. 48: 11320-11329.
Geomicrobiology meets Soil Chemistry - Part IV
May 15-16, 2014
The Soil Chemistry group travelled to Tübingen to continue a tradition of interdisciplinary research exchange with the external pageGeomicrobiology Group of external pageProfessor Andreas Kappler. Presentations were held by K. Nitzsche, J. Byrne, N. Hagemann, K. Laufer (University of Tübingen), K. Ehlert, L. ThomasArrigo, M. Jiskra (ETH Zürich), and D. Obrist (visiting professor at ETH from the DRI). The workshop included a guided tour of the Schlossmuseum from Professor N. Conard and a Swabian dinner.
Welcome Daniel!
April 7, 2014
external pageDaniel Obrist, a Professor at the Desert Research Institute in Reno, Nevada, USA, started his 3-month sabbatical today in our group. Daniel's research is concerned with the global cycling of mercury in the environment, including soil-atmosphere interactions.
New study investigating roasted Hg ore waste (calcine) reveals the largest mass dependent fractionation range of the stable Hg isotopes ever measured for an environmental material.
April 4, 2014
Smith, R.S., Wiederhold, J.G., Jew, A.D., Brown Jr., G.E., Bourdon, B., and Kretzschmar, R. (2014): Small-scale studies of roasted ore waste reveal extreme ranges of stable mercury isotope signatures. Geochim. Cosmochim. Acta 137: 1-17.
Sampling in India
April 2, 2014
Zoey, Kurt, and Ruben came back from a 10-day excursion and sampling trip to India, where chromium ore processing and leather tanning is causing massive pollution of groundwater with hexavalent Cr. A new project together with collaborators from Germany and India will address problems related to industrial waste management and resulting pollution of groundwater and soils. The picture shows groundwater from a tube well with extremely high concentrations of Cr(VI), which causes the yellow color of the water.
Welcome Zoey!
March 24, 2014
Zoey Herm, a freshly graduated PhD in chemistry from UC Berkeley, started her 2-year ETH Postdoctoral Fellowship today. Zoey's research will address redox and sorption interactions between hexavalent chromium and organic soil amendments used to immobilize Cr in polluted soils.
Sulfhydryl groups of natural organic matter can effectively compete with ferrihydrite for arsenite sorption.
February 24, 2014
Hoffmann, M., Mikutta, C., and Kretzschmar, R. (2014): Arsenite Binding to Sulfhydryl Groups in the Absence and Presence of Ferrihydrite: A Model Study. Environ. Sci. Technol. 48: 3822-3831.
Welcome Thomas!
February 1, 2014
external pageThomas Borch, Associate Professor of external pageEnviromental Soil Chemistry at Colorado State University, USA, started his 5-month sabbatical today in our group. Thomas' research deals with the redox cycling of iron and its influence on pollutant dynamics as well as the fate and degradation of emerging organic pollutants.
Congratulations Martin!
January 24, 2014
Martin Hoffmann is our newest PhD after defending his thesis "Mechanisms of Arsenite Binding to Natural Organic Matter". He is pictured here in his doctoral hat with examiners (from L to R) Dr. C. Mikutta (ETH Zurich), Prof. B. Planer-Friedrich (University Bayreuth) and Prof. R. Kretzschmar (ETH Zurich).
New Incubation study reveals that As(III) complexed by organic sulfur in peat is only slowly oxidized upon aeration.
January 13, 2014
Langner, P., Mikutta, C., and Kretzschmar, R. (2014): Oxidation of organosulfur-coordinated arsenic and realgar in peat: Implications for the fate of arsenic. Environ. Sci. Technol. 48:2281-2289.
A combined As and Fe EXAFS study provides the first information on the chemical speciation of As in highly contaminated floodplain soils of Ogosta River, Bulgaria.
November 26, 2013
Mandaliev, P.N., Mikutta, C., Barmettler, K., Kotsev, T., and Kretzschmar, R.: Arsenic species formed from arsenopyrite weathering along a contamination gradient in circumneutral river floodplain soils. Environ. Sci. Technol. 48: 208-217.
Results of the EAG Council Elections
November 14, 2013
Ruben has been elected as a new member of the EAG Council starting January 2014. The second new EAG Council member is Karim Benzerara from the CNRS in France.
EAG Website: external pagehttp://www.eag.eu.com/about/governance/council-elections/
EAG Newsletter: external pagehttp://news.eag.eu.com/newsletterView?newsletterId=15
New study reveals how sulfate and copper levels in paddy soils affect Cd speciation and solubility.
October 30, 2013
Fulda, B., Voegelin, A., and Kretzschmar, R. (2013): Redox-controlled changes in cadmium solubility and solid-phase speciation in a paddy soil as affected by reducible sulfate and copper. Environ. Sci. Technol. 47: 12775-12783.
Ternary complex formation with Fe(III)-NOM complexes takes place with As(III) too.
October 2, 2013
Hoffmann, M., Mikutta, C., and Kretzschmar, R. (2013): Arsenite binding to natural organic matter: Spectroscopic evidence for ligand exchange and ternary complex formation. Environ. Sci. Technol. 47: 12165-12173.
external pagehttp://dx.doi.org/10.1021/es4023317
Complexation with soil humic acid prevents disproportionation of Cu(I): II. Thermodynamic considerations.
September 19, 2013
Maurer, F., Christl, I., Fulda, B., Voegelin, A., and Kretzschmar, R. (2013): Copper redox transformation and complexation by reduced and oxidized soil humic acid: 2. Potentiometric titrations and dialysis cell experiments. Environ. Sci. Technol. 47: 10912-10921
external pagehttp://dx.doi.org/10.1021/es4024095
Complexation with soil humic acid prevents disproportionation of Cu(I): I. Spectroscopic evidence.
September 19, 2013
Fulda, B., Voegelin, A., Maurer, F., Christl, I., and Kretzschmar, R. (2013): Copper redox transformation and complexation by reduced and oxidized soil humic acid: 1. X-ray absorption spectroscopy study. Environ. Sci. Technol. 47: 10903-10911
external pagehttp://dx.doi.org/10.1021/es4024089
EnvironMetalIsotopes 2013
August 19-23, 2013
A conference on "Stable metal isotope fractionation - Processes and applications in environmental geochemistry", organized by Jan and colleagues from Zurich and Bern, was held at Centro Stefano Franscini at Monte Verità (Switzerland). 70 participants from research groups in 19 countries presented and discussed the latest results on stable metal isotope fractionation using theoretical, experimental, and field-based approaches and their applications in environmental studies. To free the mind, the participants hiked in the Valle Verzasca on wednesday afternoon.
Robin Smith received poster award
August 2, 2013
Congratulations to Robin on receiving the award for "Best Water Poster" at the 11th International Conference on Mercury as a Global Pollutant, sponsored from a external pageWater Society Forum, for her work on 'Source tracing using stable Hg isotope signatures in sediments downstream of the New Idria Hg mine'.
Formation of realgar (near-surface), arsenopyrite and thiolic complexed As (deep layers) identified by µ-XAS and µ-XRF in a peatland.
July 26, 2013
Langner-Hofmann, P., Mikutta, C., Suess, E., Marcus, M.A., and Kretzschmar, R. (2013): Micro-scale distribution and speciation of arsenic in peat studied with µ-XRF and µ-XAS. Environ. Sci. Technol. 47: 9706-9714
Precipitation of Cu(0) & complexation of Cu(I) by reduced organic S groups are important in periodically flooded soils if sulfide formation is limited by the amount of available sulfate.
July 25, 2013
Fulda, B., Voegelin, A., Ehlert, K. and Kretzschmar, R. (2013): Redox transformation, solid phase speciation and solution dynamics of copper during soil reduction and reoxidation as affected by sulfate availability. Geochim. Cosmochim. Acta 123: 385–402
Laboratory microcosm experiments demonstrated early mercury & copper mobilization in a flooded soil a result of Hg incorporation in biomineralized metallic Cu nanoparticles.
July 2, 2013
Hofacker, A.F., Voegelin, A., Kaegi, R., and Kretzschmar, R. (2013): Mercury mobilization in a flooded soil by incorporation into metallic copper and metal sulfide nanoparticles. Environ. Sci. Technol. 47: 7739-7746
Congratulations Felix!
June 26, 2013
Our newest PhD is Felix Maurer, who defended his thesis on "Redox and binding interactions of cations and humic acid" today. His examiners were (from left to right) Prof D. Waite (University of New South Wales), Prof. R. Kretzschmar, and Dr. I. Christl (both ETH Zurich).
Congratulations Stephan!
May 27, 2013
The third soil chemistry PhD candidate defended his thesis this month. Congratulations to Stephan Rieder, who mainly conducted his work at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), but was co-supervised by Ruben. You see him with his examination committee Prof. W. Wilcke (University of Bern), Prof. R. Kretzschmar (ETH Zurich), Dr. B. Frey (WSL) and Prof. E. Tipping (CEH, Lancaster).
Isotopically heavy Hg phases formed during ore roasting processes are assumed to influence isotopic composition of Hg leached from New Idria Hg mine.
May 10, 2013
Wiederhold, J.G., Smith, R.S., Siebner, H., Jew, A.D., Brown Jr., G.E., Bourdon, B., and Kretzschmar, R. (2013): Mercury isotope signatures as tracers for Hg cycling at the New Idria Hg mine. Environ. Sci. Technol. 47: 6137-6145
Congratulations Anke!
May 8, 2013
Anke Hofacker defended her PhD thesis today. You see her on the left, wearing the soil chemistry doctoral hat, with her examination committee Prof. A. Kappler (University of Tübingen), Dr. A. Voegelin (EAWAG), Prof. R. Kretzschmar (ETH Zurich), and Prof. J. Peña (University of Lausanne) on the CHN rooftop terrace.
Presence of Cd(II) raises the extent of orthophosphate adsorption onto hematite and the level of complexity of its surface species.
April 12, 2013
Elzinga, E.J., and Kretzschmar, R. (2013): In situ ATR-FTIR spectroscopic analysis of the co-adsorption of orthophosphate and Cd(II) onto hematite. Geochim. Cosmochim. Acta. 117: 53-64
Monte Verità conference on iron biogeochemistry
March 3-8, 2013
Ruben and colleagues from several european universities organized the conference "Iron biogeochemistry - from molecular processes to global cycles" held at Centro Stefano Franscini at Monte Verità (Switzerland), which was co-sponsored by the ESF Research Network Programme FIMIN. It brought together about 100 world-leading experts, young researchers, and PhD students interested in various aspects of iron biogeochemistry and its applications in related research fields. Remarkable scientific presentations and ample discussions were rounded off by a half-day trip to Bellinzona the 'city of three castles'.
Scorodite-type local structure of short-range ordered ferric arsenates identified by As and Fe K-edge EXAFS spectroscopy.
February 15, 2013
Mikutta, C., Mandaliev, P.N., and Kretzschmar, R. (2013): New clues to the local atomic structure of short-range ordered ferric arsenate from EXAFS spectroscopy. Environ. Sci. Technol. 47: 3122-3131
external pagehttp://dx.doi.org/10.1021/es3051795
Long-term exposure to silicate decreases potential of hematite for adsorbing inorganic arsenic.
November 19, 2012
Christl, I., Brechbühl, Y., Graf, M., and Kretzschmar, R. (2012): Polymerization of silicate on hematite surfaces and its influence on arsenic sorption. Environ. Sci. Technol. 46: 13235-13243
Temperature controls trace metal dynamics during soil flooding.
November 15, 2012
Hofacker, A.F., Voegelin, A., Kaegi, R., Weber, F.-A., and Kretzschmar, R. (2013): Temperature-dependent formation of metallic copper and metal sulfide nanoparticles during flooding of a contaminated soil. Geochim. Cosmochim. Acta 103: 316–332
Phosphate based functional groups play major role in mediating bacterial adhesion to hematite surfaces.
November 8, 2012
Elzinga, E.J., Huang, J.-H., Chorover, J., and Kretzschmar, R. (2012): ATR-FTIR spectroscopy study of the influence of pH and contact time on the adhesion of Shewanella putrefaciens bacterial cells to the surface of hematite. Environ. Sci. Technol. 46: 12848-12855
New XAS study reveals Zn speciation in blast furnace sludge.
October 5, 2012
Kretzschmar, R., Mansfeldt, T., Mandaliev, P.N., Barmettler, K., Marcus, M.A., and Voegelin, A. (2012): Speciation of Zn in blast furnace sludge from former sedimentation ponds using synchrotron X-ray diffraction, fluorescence, and absorption spectroscopy. Environ. Sci. Technol. 46: 12381-12390
Bisulfide reaction with NOM enhance its ability to bind As in anoxic environments.
September 26, 2012
Hoffmann, M., Mikutta, C. and Kretzschmar, R. (2012): Bisulfide reaction with natural organic matter enhances arsenite sorption: Insights from X-ray absorption spectroscopy. Environ. Sci. Technol. 46: 11788-11797
Hiking in Glarus
September 7-9, 2012
Soil chemistry hikers (Robin, Charlotte, Katrin, Michael, Jan, Martin, Beate, Petar, Elke, Ruben and Christof) went to the Glarus alps this year. We had three beautiful days in the mountains and thanks to the nice weather, amazing views all across the Swiss alps (including the Glarus Thrust).
Investigations about the evolution of carbon fluxes with initial ecosystem development.
September 4, 2012
Guelland, K., Hagedorn, F., Smittenberg, R.H., Göransson, H., Bernasconi, S.M., Hajdas, I., and Kretzschmar, R. (2013): Evolution of carbon fluxes during initial soil formation along the forefield of the Damma glacier, Switzerland. Biogeochemistry 113: 545-561
Soil CO2 effluxes and DOC leaching studied along a glacier forefield.
July 27, 2012
Guelland, K., Esperschütz, J., Bornhauser, D., Bernasconi, S.M., Kretzschmar, R., and Hagedorn, F. (2013): Mineralisation and leaching of C from 13C labelled plant litter along an initial soil chronosequence of a glacier forefield. Soil Biol. Biochem. 57: 237-247
external pagehttp://dx.doi.org/10.1016/j.soilbio.2012.07.002
Formation of copper-methanobactin complexes depends on copper-to-methanobactin ratios and pH.
July 15, 2012
Pesch, M.-L., Christl, I., Hoffmann, M., Kraemer, S.M. and Kretzschmar, R. (2012): Copper complexation of methanobactin isolated from Methylosinus trichosporium OB3b: pH dependent speciation and modeling. J. Inorg. Biochem. 116: 55-62
external pagehttp://dx.doi.org/10.1016/j.jinorgbio.2012.07.008
Sampling at Ogosta river
June 2-8, 2012
Several members of our group (Ruben, Christian, Iso, Petar, Kurt, Katrin and Elke) went to Bulgaria for a sampling. Accompanied by collaborators from the Bulgarian Academy of Sciences they took water, soil and plant samples along the river Ogosta, which is strongly influenced by (abandoned) mine sites.
Investigations of isotopic fractionation of Hg(II) sorption to goethite revealed a mass-dependent enrichment of light Hg isotopes on the surface.
May 21, 2012
Jiskra, M., Wiederhold, J.G., Bourdon, B., and Kretzschmar, R. (2012): Solution speciation controls mercury isotope fractionation of Hg(II) sorption to goethite. Environ. Sci. Technol. 46: 6654-6662
Field study at the Damma glacier reveals species- and age-dependent Ca isotope fractionation by alpine plants.
April 19, 2012
Hindshaw, R.S., Reynolds, B.C., Wiederhold, J.G., Kiczka, M., Kretzschmar, R., and Bourdon, B. (2013): Calcium isotope fractionation in alpine plants. Biogeochemistry 112: 373-388
Carbon dynamics of glacier forefield sensitive to climate changes.
March 2, 2012
Smittenberg, R.H., Gierga, M., Göransson, H., Christl, I., Farinotti, D., Bernasconi, S.M. (2012): Climate-sensitive ecosystem carbon dynamics along the soil chronosequence of the Damma glacier forefield, Switzerland. Glob. Change Biol. 18: 1941-1955.
external pagehttp://dx.doi.org/10.1111/j.1365-2486.2012.02654.x
Snow and Fun in Lenzerheide
February 3-5, 2012
Accompanied by some of our visitors from Tübingen and former group members we had three nice days of skiing, snowboarding and snowshoe trekking in the beautiful mountains of Lenzerheide. To the left you see some ambitious skiers, who rode the slopes despite the arctic weather with temperatures down to -25°C.
Soil Chemistry meets Geomicrobiology -Part III
February 1-2, 2012
The third time we met external pageTübingen's geomicrobiologists. During two days we had great presentations given by Dr. C. Schröder, Dr. S. Behrens, Dr. A. Picard, A. Piepenbrock, E. Melton (University of Tübingen) and Y. Brechbühl, M. Hoffmann, M. Jiskra (ETH Zurich) and a vaudois dinner in the evening. Special guest was D. Macalady (Colorado School of Mines) who's visiting professor in Tübingen. He gave a presentation about the effect of sample origins and histories on the oxidation/reduction properties of natural organic matter.
Congratulations Laurie!
January 27, 2012
Laurie Pesch defended her PhD thesis today. You see here on the left surrounded by her examination committee Prof. S. Krämer (University of Vienna), Prof. R. Kretzschmar (ETH Zurich), Dr. I. Christl (ETH Zurich) and Prof. A. Stone (Johns Hopkins University) after passing the traditional Soil Chemistry PhD exam.
Dissolved organic Cr(III)-complexes are major products of aerobic Cr(VI)-reduction by Pseudomonas corrugata 28.
December 7, 2011
Christl, I., Imseng, M., Tatti, E., Frommer, J., Viti, C., Giovannetti, L., and Kretzschmar, R. (2012): Aerobic reduction of chromium(VI) by Pseudomonas corrugata 28: Influence of metabolism and fate of reduced chromium. Geomicrobiol. J. 29: 173-185.
Spectroscopic investigations point to origin of Zn in Jurassic limestone.
November 26, 2011
Jacquat, O., Rambeau, C., Voegelin, A., Efimenko, N., Villard, A., Föllmi, K. B., and Kretzschmar, R. (2011): Origin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy: evidence from Zn speciation and distribution. Swiss Journal of Geosciences 104: 409-424.
New study provides the first spectroscopic evidence for ternary complex formation between As(V) and Fe(III)-HS complexes.
October 10, 2011
Mikutta, C., and Kretzschmar, R. (2011): Spectroscopic evidence for ternary complex formation between arsenate and ferric iron complexes of humic substances. Environ. Sci. Technol. 45: 9550-9557.
Jessica Dittmar received Fritz Scheffer Award
September 6, 2011
During the biannual meeting of the external pageGerman Soil Science Society (DBG) in Berlin, our former PhD student Dr. Jessica Dittmar received the prestigious external pageFritz-Scheffer Award for her PhD thesis “Seasonal arsenic cycling in irrigated paddy soils in Bangladesh and arsenic uptake by rice”. Jessica presented her PhD research in a plenary talk and then received the certificate from DBG president Prof. Dr. Rainer Horn.
Alpstein Hiking
August 26-28, 2011
This years hiking weekend took us to the Alpstein massif, the northernmost alpine mountains in switzerland. On the last day we climbed the highest point in this region, mount Säntis (2502m; see picture). To the left you see the soil chemistry hikers: Martin J., Martin H., Laurie, Iso, Felix, Jan, Kurt, Beate, Anke and Ruben.
EAG/FIMIN workshop in Tübingen, Germany
August 7-11, 2011
Ruben and colleagues from the University of Tübingen (Germany) and Colorado State University (USA) organized a Short Course entitled “Tools in Environmental Biogeochemistry - Opportunities and Limitations”. The course was attended by 20 PhD students from five different countries. Leading experts in the field introduced the students to a variety of advanced analytical techniques, including Mössbauer spectroscopy, SEM/FIB, microelectrodes, and synchrotron X-ray spectroscopy and microscopy. The course included a full-day visit at the synchrotron ANKA (Karlsruhe) and ended with a Stocherkahn trip on the river Neckar in Tübingen.
Microbial reduction of adsorbed As(V) is strongly affected by bacteria-mineral interactions promoting As(V) desorption.
August 5, 2011
Huang, J.-H., Voegelin, A., Pombo, S.A., Lazzaro, A., Zeyer, J., and Kretzschmar, R. (2011): Influence of arsenate adsorption to ferrihydrite, goethite, and boehmite on the kinetics of arsenate reduction by Shewanella putrefaciens strain CN-32. Environ. Sci. Technol. 45: 7701-7709.
Multidisciplinary research at the Damma Glacier forefield: The project BigLink
August 1, 2011
Bernasconi, S.M. and 39 other authors (2011): Chemical and biological gradients along the Damma Glacier soil chronosequence, Switzerland. Vadose Zone J. 10, 867-883.
New study shows how stable Fe isotopes are fractionated during biotite/chlorite weathering in a granitic glacier forefield.
July 18, 2011
Kiczka, M., Wiederhold, J.G., Frommer, J., Voegelin, A., Kraemer, S.M., Bourdon, B., and Kretzschmar, R. (2011): Iron speciation and isotope fractionation during silicate weathering and soil formation in an alpine glacier forefield chronosequence. Geochim. Cosmochim. Acta 75: 5559-5573
New EXAFS study systematically demonstrates the influence of different hydrobenzoic acids on the formation and structure of ferrihydrite formed during Fe(III) polymerization
June 13, 2011
Mikutta, C. (2011): X-ray absorption spectroscopy study on the effect of hydroxybenzoic acids on the formation and structure of ferrihydrite. Geochim. Cosmochim. Acta 75: 5122-5139
Congratulations Ruth!
June 8, 2011
Ruth Hindshaw defended her PhD thesis today. She is pictured here with her beautiful doctoral hat on the PhD apéro. Her thesis “Chemical weathering and calcium isotope fractionation in a glaciated catchment” was conducted within the interdisciplinary project BigLink.
Cultural trip to Dresden
May 27-29, 2011
The soil chemistry culture vultures (see picture: Beate, Charlotte, Laurie, Martin H., Felix, Iso, Lauren, Robin and Anke) enjoyed three days in the capital of Saxony with a nice sightseeing tour, opera and museum visits and a lot of good food! On the last day we relaxed on a hike in the Elbe Sandstone Mountains.
Systematic investigations of seasonal and diurnal variations in stream water chemistry of the Damma glacier forefield
April 27, 2011
Hindshaw, R.S., Tipper, E.T., Reynolds, B.C., Lemarchand, E., Wiederhold, J.G., Magnusson, J., Bernasconi, S.M., Kretzschmar, R., and Bourdon, B. (2011): Hydrological control of stream water chemistry in a glacial catchment (Damma Glacier, Switzerland). Chemical Geology, 285: 215-230
external pagehttp://dx.doi.org/doi:10.1016/j.chemgeo.2011.04.012
FIMIN Spring School in Cordoba, Spain
March 6-11, 2011
Ruben and colleagues from the FIMIN network taught a Spring School on “Iron in the Environment - From Nature to the Laboratory”. One of the highlights was the excursion to Rio Tinto, one of the world’s largest acid mine drainage sites. Information about future FIMIN events can be found on the FIMIN website
Does EPS affect the sorption of arsenic on Fe(III)-(hydr)oxides?
March 04, 2011
Huang, J.-H., Elzinga, E.J., Brechbuehl, Y., Voegelin, A., and Kretzschmar, R. (2011): Impacts of Shewanella putrefaciens strain CN-32 cells and extracellular polymeric substances on the sorption of As(V) and As(III) on Fe(III)-(hydr)oxides. Environ. Sci. Technol. 45: 2804–2810
Quantification of 'labile' zinc in soils: New insights from combining methods
December 7, 2010
Degryse, F., Voegelin, A., Jacquat, O., Kretzschmar, R., and Smolders, E. (2011): Characterization of zinc in contaminated soils: Complementary insights from isotopic exchange, batch extractions, and XAFS spectroscopy. Europ. J. Soil Sci., 62: 318–330
external pagehttp://dx.doi.org/10.1111/j.1365-2389.2010.01332.x
Intermittent irrigation may be a promising means of reducing arsenic input to paddy soils
December 7, 2011
Roberts, L.C., Hug, S.J., Voegelin, A., Dittmar, J., Kretzschmar, R., Wehrli, B., Saha, G.C., Badruzzaman, A.B.M., Ali, M.A. (2011): Arsenic dynamics in porewater of an intermittently irrigated paddy field in Bangladesh. Environ. Sci. Technol. 45: 971–976
First sampling in New Idria
December 13, 2010
In December Ruben, Jan, Robin and and some people of Gordon Brown's group (Stanford University) went to California for a sampling at the now-inoperative mercury mine in New Idria. They want to investigate the fractionation mechanisms of Hg isotopes in soils and plants. On the left side you see a picture of Robin at work.
Contamination source phases influence the formation of new Zn species in soils
December 9, 2010
Voegelin, A., Jacquat, O., Pfister, S., Barmettler, K., Scheinost, A.C., and Kretzschmar, R. (2011): Time-dependent changes of Zn-speciation in four soils contaminated with zincite or sphalerite. Environ. Sci. Technol. 45: 255–261
A micro-focused XAS study reveals the distribution of As, Fe, and Mn around rice roots
December 3, 2010
Frommer, J., Voegelin, A., Dittmar, J., Marcus, M., and Kretzschmar, R. (2011): Biogeochemical processes and As enrichment around rice roots in paddy soil: Results from bulk and micro-focused X-ray spectroscopies. Europ. J. Soil Sci., 62: 305–317
external pagehttp://dx.doi.org/10.1111/j.1365-2389.2010.01328.x
Discussion about arsenic accumulations in rice
November 12, 2010
The british Emerging Health Threats Forum published a nice article about accumulations of arsenic in rice which is based on our ES&T paper from March 2010. They discussed and commented our results together with several international environmental scientists.
New field and pot studies on As uptake by wetland rice
November 2, 2010
Dittmar, J., Voegelin, A., Maurer, F., Roberts, L.C., F., Hug, S.J., Saha, G.C., Ali, M.A., Badruzzaman, A.B.M., and Kretzschmar, R. (2010): Arsenic in soil and irrigation water affects As uptake by rice: Complementary insights from field and pot studies. Environ. Sci. Technol. 44: 8842–8848
Fractionation of calcium isotopes during the initial stages of weathering
October 8, 2010
Hindshaw, R.S., Reynolds, B.C., Wiederhold, J.G., Kretzschmar, R., and Bourdon, B. (2011): Calcium isotopes in a proglacial weathering environment: Damma glacier, Switzerland. Geochim. Cosmochim. Acta 75: 106-118
Hiking in Ticino
September 24-26, 2010
The annually hiking weekend ouf our group took us 1,704 m above sea level on top of Monte Generoso. There we enjoyed the overwhelming scenery over Lugano, the Swiss Alps and Po Valley. To the left is a picture of the soil chemistry hikers: Martin J., Felix, Martin H., Beate, Laurie, Kurt and Charlotte.
Return visit in Tübingen: Geomicrobiology meets Soil Chemistry - Part II
September 9-10, 2010
Again, we had a great series of talks during two days presented by Dr. S. Behrens, Dr. C. Schmidt, U. Dippon, F. Hegler (external pageUniversity of Tübingen) and Dr. I. Christl, Dr. P. Mandaliev, Dr. J. Weinhold, B. Fulda (ETH Zurich). In the evening we were invited to Andreas Kappler's home for a typical Swabian dinner. Another highlight was a "Stocherkahnfahrt" on the beautiful river Neckar.
Congratulations Mirjam!
September 3, 2010
Mirjam Kiczka-Cyriac defended her PhD thesis today. She is pictured here with her examination committee Prof. W. Wilcke (University of Bern), Dr. J. Wiederhold (ETH Zurich), Prof. R. Kretzschmar (ETH Zurich) and Prof. S. Krämer (University of Vienna) (Prof. Bourdon (ETH Zurich) is unfortunately missing) after passing the Soil Chemistry graduation ceremony.
How small organic molecules affect the structure of ferrihydrite
June 30, 2010
Mikutta, C., Frommer, J., Voegelin, A, Kaegi, R., and Kretzschmar, R. (2010): Effect of citrate on the local Fe coordination in ferrihydrite, arsenate binding, and ternary arsenate complex formation. Cosmochim. Geochim. Acta 74: 5574-5592
New publication in Bangladesh arsenic project
March 17, 2010
Dittmar, J., Voegelin, A., Roberts, L.C., Hug, S.J., Saha, G.C., Ali, M.A., Badruzzaman, A.B.M., and Kretzschmar, R. (2010): Arsenic accumulation in a paddy field in Bangladesh: Seasonal dynamics and trends over a three-year monitoring period. Environ. Sci. Technol. 44: 2925-2931.
New publication on iron isotope fractionation during dissolution processes
February 23, 2010
Kiczka, M., Wiederhold, J.G., Frommer, J., Kraemer S.M., Bourdon, B., Kretzschmar, R. (2010): Iron isotope fractionation during proton- and ligand-promoted dissolution of primary phyllosilicates . Geochim. Cosmochim. Acta 74: 3112-3128.
external pagehttp://dx.doi.org/doi:10.1016/j.gca.2010.02.018
Soil Chemistry meets Geomicrobiology
February 11, 2010
The last two days a interdisciplinary meeting of our group and the external pagegeomicrobiology group of the University of Tübingen was held. Presentations were given by Dr. J.-H. Huang, P. Langner, F. Maurer, A. Hofacker (ETH Zurich) and Dr. M. Obst, C. Hohmann, P. Sharma, M. Emmerich (University of Tübingen). In the evening we enjoyed a delicious cheese-fondue at Zurich's Chäsalp.
Borch et al. Critical Review on Biogeochemical Redox Processes and their Impact on Contaminant Dynamics
December 14, 2009
Borch, T., Kretzschmar, R., Kappler, A., Van Cappellen, Ph., Ginder-Vogel, M., Voegelin, A., and Campbell, K. (2010): Biogeochemical redox processes and their impact on contaminant dynamics. Environ. Sci. Technol. 44: 15-23
Roberts et al. As release from paddy soils during monsoon flooding counteracts long-term As accumulation in rice fields
December 13, 2009
Roberts, L.C., Hug, S.J., Dittmar, J., Voegelin, A., Kretzschmar, R., Wehrli, B., Cirpka, O., Saha, G.C., Ali, M.A., and Badruzzaman, A.B.M. (2010): Arsenic mobilization from paddy soils during monsoon flooding. Nature Geosci. 3: 53-59
Weber et. al. on the mobilization of As during Fe and As reduction in a floodplain soil
November 18, 2009
Weber, F.-A., Hofacker, A.F., Voegelin, A., and Kretzschmar, R. (2010): Temperature dependence and coupling of iron and arsenic reduction and release during flooding of a contaminated soil. Env. Sci. Technol. 44: 116-122