Soil Chemistry

Soil Chemistry News

Prof. Jeff Catalano joined us as a guest professor for a 6-month sabbatical.

Prof. Ruben Kretzschmar

The research and teaching activities of the group aim at an improved mechanistic and quantitative understanding of processes that control the mobility, bioavailability, and cycling of essential and potentially toxic trace elements in terrestrial environments (e.g., Zn, Cu, Cd, Pb, Cr, As, Hg). This requires a combined approach using multiple analytical techniques in field studies, laboratory studies with soils under controlled environmental conditions, as well as experiments with simplified model systems. Advanced analytical techniques used by the group include synchrotron X-ray absorption fine structure (XAFS) spectroscopy, scanning transmission X-ray microscopy (STXM) and micro-spectroscopy, ATR-FT-IR spectroscopy, and others. The group has also developed an active research programme in collaboration with the Isotope Geochemistry Group of ETH Zurich to explore the use of non-traditional stable isotopes as novel tracers for the environmental behaviour and cycling of the respective elements or as tracers for chemical weathering processes (e.g., Fe, Ca, Li, Hg).

News Feed

May 6, 2015

New study suggests that stable Hg isotopes can be used to estimate evaporation losses of Hg from boreal forest soils to the atmosphere.

Jiskra, M., Wiederhold, J.G., Skyllberg, U., Kronberg, R.-M., Hajdas, I., and Kretzschmar, R. (2015): Mercury deposition and re-emission pathways in boreal forest soils investigated with Hg isotope signatures. Environ. Sci. Tech. (Accepted).

May 4, 2015

Welcome new group members!

Four new group members have joined the Soil Chemistry Group: Natacha Van Groeningen (Belgium) and Kevin Hoffmann (Germany) started their PhD studies on a project on redox biogeochemistry, Chih-Ping Tso (Taiwan) is a 1-year guest PhD student, and Dr. Amy Atkins (UK) started on a postoc position. Welcome!

March 23-27, 2015

Scientific Workshop in Wuhan

Ruben, Iso and Kurt visited Huazhong Agricultural University in Wuhan, China, for a 2-day scientific workshop and exchange with Prof. Wenfeng Tan and his colleagues. We thank our hosts for the incredible hospitality and the extremely interesting visit!

March 15-22, 2015

Scientific Visit in Hunan Province

Ruben, Iso and Kurt visited Nanjing Agricultural University in China for a scientific workshop and discussions with Prof. Fangjie Zhao and his colleagues, where Ruben and Iso presented two lectures. They visited field research sites around Nanjing and in Hunan Province, and also presented seminars at Nanjing University, where they were hosted by Prof. Lena Ma and her group members. Ruben also presented another seminar at the Chinese Academy of Sciences Institute of Subtropical Agriculture in Changsha City, Hunan Province. We thank our hosts for the welcoming hospitality and the interesting visits and discussions!

March 18, 2015

Experiments investigating isotope fractionation of Hg(II) during precipitation of metacinnabar and montroydite reveal mass-dependent enrichments of light Hg isotopes in the precipitates relative to the dissolved phase.

Smith, R., Wiederhold, J., Kretzschmar, R. (2015): Mercury isotope fractionation during precipitation of metacinnabar (β-HgS) and montroydite (HgO). Environ. Sci. Tech. 49, 4324-4334.

February 2, 2015

Welcome Jeff!

Jeffrey Catalano, Associate Professor in the Department of Earth and Planetary Sciences at Washington University, USA, has started his 6-month sabbatical in our group. Jeff's research interests include biogeochemical element cycling, contaminant fate, and mineral weathering on Earth and Mars.

February 2, 2015

Critical review article in ES&T provides introduction into the emerging research field of metal stable isotopes and their application as source and process tracers in environmental geochemistry.

Wiederhold, J. (in press): Metal stable isotope signatures as tracers in environmental geochemistry. Environ. Sci. Tech. 49, 2606-2624.

Jan. 30 - Feb. 1, 2015

Snow&Fun Weekend 2015

This year's Snow&Fun Weekend took place again in Lenzerheide! Fresh snow and sunshine made for a really enjoyable weekend.

January 23, 2015

Congratulations Peggy!

Peggy Hofmann received the ETH Medaille for an outstanding PhD Thesis; "Arsenic Speciation in a Minerotrophic Peatland: Natural Organic Matter and Mineral Controls."

December 18, 2014

Congratulations Robin!

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). 

December 11, 2014

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.

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.

December 2, 2014

Congratulations Katrin!

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'.

December 1, 2014

New study on Hg isotopes in contaminated sediments reveals distinct "isotopic fingerprints" for sites polluted by different industrial sources in Sweden.

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.

October 31, 2014

Congratulations Tinu!

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). 

October 30, 2014

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.

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.

October 27, 2014

Study of natural Fe-rich flocs reveals elevated trace element contents and arsenate binding to floc Fe(III)-(oxyhydr)oxides.

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.

October 3, 2014

Isotope exchange experiments revealed slow and incomplete exchange of Hg(II) bound to natural organic matter and goethite.

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.

September 25, 2014

Hiking day 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.

September 22, 2014

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.

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.

May 15-16, 2014

Geomicrobiology meets Soil Chemistry - Part IV

The Soil Chemistry group travelled to Tübingen to continue a tradition of interdisciplinary research exchange. 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.

April 7, 2014

Welcome Daniel!

Daniel 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.

April 4, 2014

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.

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.

April 2, 2014

Sampling in India

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.

March 24, 2014

Welcome Zoey!

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.

February 24, 2014

Sulfhydryl groups of natural organic matter can effectively compete with ferrihydrite for arsenite sorption.

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.

February 1, 2014

Welcome Thomas!

Thomas Borch, Associate Professor of Enviromental 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.

January 24, 2014

Congratulations Martin!

Martin Hoffmann is our newest PhD after defending his thesis "Mechanisms of Arsenite Binding to Natural Organic Matter". He is pictured here in his soil chemistry 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). 

January 13, 2014

New Incubation study reveals that As(III) complexed by organic sulfur in peat is only slowly oxidized upon aeration.

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.

November 29, 2013

Congratulations Peggy!

Peggy Hofmann defended her PhD thesis today. You see her to the left, wearing the soil chemistry doctoral hat. Her examiners were Dr. J. Rothwell (University of Manchester), Dr. C. Mikutta and Prof. R. Kretzschmar (both ETH Zurich). 

November 26, 2013

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.

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.

November 14, 2013

Results of the EAG Council Elections

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:

EAG  Newsletter:

October 30, 2013

New study reveals how sulfate and copper levels in paddy soils affect Cd speciation and solubility.

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.

October 4-6, 2013

Hiking weekend 2013

Yet another time the soil chemistry hiking weekend took place. This years hikers (Jan, Kurt, Christian, Ruben, Michael, Laurel, Katrin and Worachart) went to two alpine huts in the Prättigau region near the Austrian border.

October 2, 2013

Ternary complex formation with Fe(III)-NOM complexes takes place with As(III) too.

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.

September 19, 2013

Complexation with soil humic acid prevents disproportionation of Cu(I): II. Thermodynamic considerations.

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

September 19, 2013

Complexation with soil humic acid prevents disproportionation of Cu(I): I. Spectroscopic evidence.

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

August 18-23, 2013

EnvironMetalIsotopes 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.

EMI conference homepage

August 2, 2013

Robin Smith received poster award

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 Water Society Forum, for her work on 'Source tracing using stable Hg isotope signatures in sediments downstream of the New Idria Hg mine'.

July 26, 2013

Formation of realgar (near-surface), arsenopyrite and thiolic complexed As (deep layers) identified by µ-XAS and µ-XRF in a peatland.

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

July 25, 2013

Precipitation of Cu(0) and complexation of Cu(I) by reduced organic S groups are important processes in periodically flooded soils if sulfide formation is limited by the amount of available sulfate.

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

July 2, 2013

Laboratory microcosm experiments demonstrated early mercury and copper mobilization in a flooded soil to be a result of Hg incorporation in biomineralized metallic Cu nanoparticles.

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

June 26, 2013

Congratulations Felix!

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). 

May 27, 2013

Congratulations Stephan!

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).

May 17, 2013

Congratulations Beate!

Today Beate Fulda defended her PhD thesis. She is pictured here on the PhD apéro surrounded by her examination committee Dr. G. Sarret (University of Grenoble), Dr. A. Voegelin (EAWAG) and Prof. R. Kretzschmar (ETH Zurich).

May 10, 2013

Isotopically heavy Hg phases formed during ore roasting processes are assumed to influence isotopic composition of Hg leached from New Idria Hg mine.

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

May 8, 2013

Congratulations Anke!

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.

April 12, 2013

Presence of Cd(II) raises the extent of orthophosphate adsorption onto hematite and the level of complexity of its surface species.

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

March 3-8, 2013

Monte Verità conference on iron biogeochemistry

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'. 

FIMIN conference homepage

February 15, 2013

Scorodite-type local structure of short-range ordered ferric arsenates identified by As and Fe K-edge EXAFS spectroscopy. 

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

November 19, 2012

Long-term exposure to silicate decreases potential of hematite for adsorbing inorganic arsenic

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

November 15, 2012

Temperature controls trace metal dynamics during soil flooding

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

November 8, 2012

Phosphate based functional groups play major role in mediating bacterial adhesion to hematite surfaces

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

October 22, 2012

Methanobactin capable of mobilizing Cu from humic acid via fast ligand exchange reaction

Pesch, M.-L., Hoffmann, M., Christl, I., Kraemer, S.M. and Kretzschmar, R. (2013): Competitive ligand exchange between Cu-humic acid complexes and methanobactin. Geobiology 11: 44-54

October 5, 2012

New XAS study reveals Zn speciation in blast furnace sludge

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

September 26, 2012

Bisulfide reaction with NOM enhance its ability to bind As in anoxic environments

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

September 7-9, 2012

Hiking in Glarus

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).

September 4, 2012

Investigations about the evolution of carbon fluxes with initial ecosystem development

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

July 27, 2012

Soil CO2 effluxes and DOC leaching studied along a glacier forefield

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

July 18, 2012

Silver nanoparticles formed through reaction of reduced humic acid with Ag(I). 

Maurer, F., Christl, I., Hoffmann, M., and Kretzschmar, R. (2012): Reduction and reoxidation of humic acid: Influence on speciation of cadmium and silver. Environ. Sci. Technol. 46: 8808-8816

July 15, 2012

Formation of copper-methanobactin complexes depends on copper-to-methanobactin ratios and pH.

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

June 2-8, 2012

Sampling at Ogosta river

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.

May 21, 2012

Investigations of isotopic fractionation of Hg(II) sorption to goethite revealed a mass-dependent enrichment of light Hg isotopes on the surface.

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

April 19, 2012

Field study at the Damma glacier reveals species- and age-dependent Ca isotope fractionation by alpine plants.

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

March 19, 2012

Carbonate is capable of remobilizing arsenic from hematite surfaces.

Brechbühl, Y., Christl, I., Elzinga, E.J., and Kretzschmar, R. (2012): Competitive Sorption of Carbonate and Arsenic to Hematite: Combined ATR-FTIR and Batch Experiments.  J. Colloid Interface Sci. 377: 313-321.

March 2, 2012

Carbon dynamics of glacier forefield sensitive to climate changes.

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.

February 23, 2012

Calcium binding by humic acids is primarily controlled by electrostatic forces and specific binding to carboxylic groups.

Christl, I. (2012): Ionic strength- and pH-dependence of calcium binding by terrestrial humic acids. Environ. Chem. 9: 89-96.

February 3-5, 2012

Snow and Fun in Lenzerheide

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.

February 1-2, 2012

Soil Chemistry meets Geomicrobiology -Part III

The third time we met Tübingens 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.    

January 27, 2012

Congratulations Laurie!

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.

December 7, 2011

Dissolved organic Cr(III)-complexes are major products of aerobic Cr(VI)-reduction by Pseudomonas corrugata 28.

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.

November 27, 2011

Spectroscopic study reveals the mechanism of arsenic binding to natural organic matter in wetlands.
Langner, P., Mikutta, C., and Kretzschmar, R. (2012): Arsenic sequestration by organic sulphur in peat. Nature Geoscience 5: 66-73.

November 26, 2011

Spectroscopic investigations point to origin of Zn in Jurassic limestone.

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.

October 10, 2011

New study provides the first spectroscopic evidence for ternary complex formation between As(V) and Fe(III)-HS complexes.
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.

September 6, 2011

Jessica Dittmar received Fritz Scheffer Award

During the biannual meeting of the German Soil Science Society (DBG) in Berlin, our former PhD student Dr. Jessica Dittmar received the prestigious Fritz-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.

August 26-28, 2011

Alpstein Hiking

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. 

August 7-11, 2011

EAG/FIMIN workshop in Tübingen, Germany

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.

Link to FIMIN homepage

August 5, 2011

Microbial reduction of adsorbed As(V) is strongly affected by bacteria-mineral interactions promoting As(V) desorption.
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.

August 1, 2011

Multidisciplinary research at the Damma Glacier forefield: The project BigLink
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.

July 18, 2011

New study shows how stable Fe isotopes are fractionated during biotite/chlorite weathering in a granitic glacier forefield.

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

June 13, 2011

New EXAFS study systematically demonstrates the influence of different hydrobenzoic acids on the formation and structure of ferrihydrite formed during Fe(III) polymerization

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

June 8, 2011

Congratulations Ruth!

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.

May 27-29, 2011

Cultural trip to Dresden

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.

April 27, 2011

Systematic investigations of seasonal
and diurnal variations in stream water chemistry of the Damma glacier forefield

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

April 26-27, 2011

New Idria revisited

Ruben, Robin, Peggy, and our collaborators from Stanford University returned to New Idria in April for soil sampling around the historic mercury mine. On the picture, we are not panning for gold nuggets, but for elemental mercury in the creek!

March 6-11, 2011

FIMIN Spring School in Cordoba, Spain

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

Link to FIMIN homepage

March 04, 2011

Does EPS affect the sorption of arsenic on Fe(III)-(hydr)oxides?

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

February 07, 2011

Two-step purification procedure to isolate Cu-free methanobactin

Pesch, M.-L., Christl, I., Barmettler, K., Kraemer, S.M., Kretzschmar, R. (2011): Isolation and purification of Cu-free methanobactin from Methylosinus trichosporium OB3b. Geochem. Trans. 12:2

December 17, 2010

Quantification of 'labile' zinc in soils: New insights from combining methods

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

December 17, 2010

Intermittent irrigation may be a promising means of reducing arsenic input to paddy soils

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

December 15, 2010

New review article by Jen-How Huang and coauthors on organic arsenic species

Huang, J.-H., Hu, K.-N., and Decker, B. (2011): Organic arsenic in the soil environment: Speciation, occurrence, transformation, and adsorption behavior. Water, Air, and Soil Pollut. 219:401–415.

December 13, 2010

First sampling in New Idria

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. 

December 9, 2010

Contamination source phases influence the formation of new Zn species in soils

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

December 3, 2010

A micro-focused XAS study reveals the distribution of As, Fe, and Mn around rice roots

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

November 12, 2010

Discussion about arsenic accumulations in rice

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.

November 2, 2010

New field and pot studies on As uptake by wetland rice

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

October 8, 2010

Fractionation of calcium isotopes during the initial stages of weathering

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

September 24-26, 2010

Hiking in Ticino

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. 

September 9-10, 2010

Return visit in Tübingen:
Geomicrobiology meets Soil Chemistry - Part II

Again, we had a great series of talks during two days presented by Dr. S. Behrens, Dr. C. Schmidt, U. Dippon, F. Hegler (University 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.

September 3, 2010

Congratulations Mirjam!

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.

August 2, 2010

XAS study about the structure of Fe(III)-Cr(III)-oxyhydroxides

Frommer, J., Nachtegaal, M., Czekaj, I., and Kretzschmar, R. (2010): The Cr X-ray absorption K-edge structure of poorly crystalline Fe(III)-Cr(III)-oxyhydroxides. Am. Mineralog. 95, 1202–1213

July 26, 2010

How iron isotopes fractionate during uptake by plants

Kiczka, M., Wiederhold, J.G., Kraemer, S.M., Bourdon, B., and Kretzschmar, R. (2010): Iron isotope fractionation during Fe uptake and translocation in alpine plants. Environ. Sci. Technol. 44: 6144–6150

July 2, 2010

Reduction of humic acid increase the amount of proton-reactive sites of humic acid

Maurer, F., Christl, I., and Kretzschmar, R. (2010): Reduction and reoxidation of humic acid: Influence on spectroscopic properties and proton binding. Env. Sci. Technol. 44: 5787–5792

June 30, 2010

How small organic molecules affect the structure of ferrihydrite

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

June 4, 2010

New sequential extraction method for speciation of arsenic

Huang, J.-H., and Kretzschmar, R. (2010): Sequential extraction method for speciation of arsenate and arsenite in mineral soils. Anal. Chem. 82: 5534–5540

May 5, 2010

News about mercury isotope fractionation

Wiederhold, J.G., Cramer, C.J., Daniel, K., Infante, I., Bourdon, B., and Kretzschmar, R. (2010): Equilibrium mercury isotope fractionation between dissolved Hg(II) species and thiol-bound Hg. Environ. Sci. Technol. 44: 4191-4197

March 17, 2010

New publication in Bangladesh arsenic project

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.

February 23, 2010

New publication on iron isotope fractionation during dissolution processes

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

February 11-12, 2010

Soil Chemistry meets Geomicrobiology

The last two days a interdisciplinary meeting of our group and the geomicrobiology 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.

January, 2010

Soil Science "Bible" newly released

16th edition of "Scheffer/Schachtschabel - Lehrbuch der Bodenkunde" is released with a fully revised 5th chapter ("Chemische Eigenschaften und Prozesse") by R. Kretzschmar

January 1, 2010

ES&T focus issue on Biogeochemical Redox Processes released

Edited by associate editor Ruben Kretzschmar and several guest editors.

December 14, 2009

Borch et al. Critical Review on Biogeochemical Redox Processes and their Impact on Contaminant Dynamics

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

December 13, 2009

Roberts et al. As release from paddy soils during monsoon flooding counteracts long-term As accumulation in rice fields

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

November 18, 2009

Weber et. al. on the mobilization of As during Fe and As reduction in a floodplain soil

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


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