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Language: English

In: Water, Air, and Soil Pollution, 2010, Vol.205(1), pp.93-105

Description: As floodplain soils are often contaminated, we studied the release of trace metals from three topsoil horizons in column experiments with variable flow interruptions and flow velocities, compared it with that in batch leaching tests and evaluated the column data by inverse simulations. Only small proportions (〈1%) of trace metals present in the neutral and humic soils were mobilised by the batch leaching tests and the column experiments. Release of Cr, Cu, Ni and Zn in the column experiments was rate-limited, as detected by increased concentrations after flow interruptions. A combination of linear equilibrium and non-equilibrium isotherms reflected the Ni and Zn elution data, with Zn release being slower. Simulated values for initially bound metals available for release are in the same order of magnitude as those determined by the batch leaching tests. However, the consistency of both experimental approaches decreases with increasing rate limitation, as detected here for Zn.

Keywords: Soil contamination ; Trace metals ; Column experiment ; Kinetics ; Wetland soils

ISSN: 0049-6979

E-ISSN: 1573-2932

DOI: 10.1007/s11270-009-0058-0

URL: View full text in Springer (Subscribers only)

Language: English

In: Journal of Colloid And Interface Science, Sept 1, 2013, Vol.405, p.44(7)

Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jcis.2013.05.041 Byline: Matthias Handel, Thilo Rennert, Kai U. Totsche Abstract: Display Omitted Article History: Received 20 February 2013; Accepted 17 May 2013

Keywords: Oxides ; Manganese Compounds

ISSN: 0021-9797

Source: Cengage Learning, Inc.

Language: English

In: Environmental Pollution, August, 2013, Vol.179, p.315(11)

Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.envpol.2013.03.041 Byline: Markus Wehrer, Thilo Rennert, Kai Uwe Totsche Abstract: Mass transfer processes of pollutants from non-aqueous phase liquids (NAPL) may control groundwater pollution at abandoned industrial sites. We studied release kinetics of polycyclic aromatic hydrocarbons (PAHs) from fresh and aged tar phases using a dialysis tubing technique. Time for equilibration ranged from several days to more than three years. For fresh tar materials the release seems to be limited by retarded pore diffusion, while for two of three aged tars diffusion limited release influenced by dissolved organic matter (DOM) was assumed. The equilibration process was driven by solubilization thermodynamics expressed by Raoult's law. Yet, solubility enhancement was observed potentially due to the presence of organic mobile sorbents. The results show that the release of PAHs from tar phases is generally rate limited and partitioning according to Raoult's law is the driving mechanism of the exchanges process. Author Affiliation: (a) Institute of Geosciences, Friedrich Schiller University of Jena, Burgweg 11, 07743 Jena, Germany (b) Department of Earth and Environmental Sciences, Rutgers, The State University of New Jersey, Smith Hall Room 136, 101 Warren Street, Newark, NJ 07102, United States Article History: Received 31 October 2012; Revised 13 March 2013; Accepted 19 March 2013

Keywords: Water Pollution ; Thermodynamics ; Groundwater ; Polycyclic Aromatic Hydrocarbons ; Pollution Control

ISSN: 0269-7491

Source: Cengage Learning, Inc.

Language: English

In: Environmental pollution, 2011, Vol.159(5), pp.1398-1405

Description: Arsenic mobility may increase in liquid phase due to association with colloidal Fe oxides. We studied the association of As with Fe oxide colloids in the effluent from water-saturated soil columns run under anoxic conditions. Upon exfiltration, the solutions, which contained Fe²⁺, were re-aerated and ferrihydrite colloids precipitated. The entire amount of effluent As was associated with the ferrihydrite colloids, although PO₄ ³⁻, SiO₄ ⁴⁻, CO₃ ²⁻ and dissolved organic matter were present in the effluent during ferrihydrite colloid formation. Furthermore, no subsequent release of As from the ferrihydrite colloids was observed despite the presence of these (in)organic species known to compete with As for adsorption on Fe oxides. Arsenic was bound via inner-sphere complexation on the ferrihydrite surface. FTIR spectroscopy also revealed adsorption of PO₄ ³⁻ and polymerized silica. However, these species could not impede the quantitative association of As with colloidal ferrihydrite in the soil effluents. ; p. 1398-1405.

Keywords: Iron Oxides ; Dissolved Organic Matter ; Effluents ; Arsenic ; Adsorption ; Polymerization ; Anaerobic Conditions ; Ferrihydrite ; Iron ; Colloids ; Silica ; Fourier Transform Infrared Spectroscopy ; Soil

ISSN: 0269-7491

DOI: 10.1016/j.envpol.2011.01.001

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Language: English

In: Water, Air, and Soil Pollution, 2010, Vol.206(1), pp.395-396

Description: Byline: Thilo Rennert (1), Jorg Rinklebe (2) Author Affiliation: (1) Lehrstuhl Hydrogeologie, Institut fur Geowissenschaften, Friedrich-Schiller-Universitat Jena, Burgweg 11, 07749, Jena, Germany (2) Boden- und Grundwassermanagement, Fachbereich D, Bergische Universitat Wuppertal, Pauluskirchstr. 7, 42285, Wuppertal, Germany Article History: Registration Date: 26/05/2009 Online Date: 25/06/2009 Article note: The online version of the original article can be found under http://dx.doi.org/10.1007/s11270-009-0058-0.

Keywords: Soils;

ISSN: 0049-6979

E-ISSN: 1573-2932

DOI: 10.1007/s11270-009-0110-0

URL: View full text in Springer

Language: English

In: Chemical Geology, Nov 25, 2012, Vol.332-333, p.116(8)

Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chemgeo.2012.09.046 Byline: Thilo Rennert, Karin Eusterhues, Vincent De Andrade, Kai U. Totsche Keywords: Geogenic CO.sub.2; Soil formation; Fe speciation; Green rust; Organic complexation Abstract: Geogenic CO.sub.2, which ascends on so-called mofette sites, may affect development and properties of soils. Therefore, we studied soils on a mofette site in the Czech Republic at three spots differing in the partial pressures of soil CO.sub.2 (p(CO.sub.2)=0.04, 1, and 1). We recorded 69 Fe K-XANES spectra in 5 regions of interest on 3 thin sections in fluorescence mode. Iron was enriched in filled pores, e.g., former root channels. Generally, most of the Fe was identified in different clay minerals (smectites, illites and chlorites). Minor pedogenic Fe contributors were ferrihydrite, green rust, magnetite, maghemite, vivianite and siderite, whereas typical soil Fe (hydr)oxides such as goethite, hematite or lepidocrocite were never doubtlessly identified. The Fe(II)-containing minerals were particularly detected at p(CO.sub.2)=1 indicating an effect of soil CO.sub.2 on the formation of secondary Fe phases. Organic Fe complexes were less important, and their formation seemed to be inhibited at p(CO.sub.2)=1. We thus conclude that geogenic CO.sub.2 affects pedogenesis and causes quantitative and qualitative variations of Fe speciation. Article History: Received 11 July 2012; Revised 26 September 2012; Accepted 27 September 2012 Article Note: (miscellaneous) Editor: Dr. J. Fein

Keywords: Iron (Metal) ; Smectite ; Iron Oxides ; Soils ; Chlorites (Minerals) ; Iron Ores

ISSN: 0009-2541

Source: Cengage Learning, Inc.

Language: English

In: Soil Research, 2018, Vol.56(4), p.396-403

Description: The presence of geogenic CO has been recently identified as a soil-forming factor in soil on mofette sites. Topsoil samples (with a maximum CO concentration of 52% at 10 cm depth) were studied along a transect on a mofette site in the NW Czech Republic to further understand the processes within soil and the soil properties induced by CO in the soil atmosphere. Geogenic CO negatively affected the cation exchange capacity, the ratio of exchangeable Ca and Mg, and the total contents of Al, Mg and Mn. No effect was detected on a chemical index of weathering and the mineralogical composition of the clay fractions, which might be explained by the acidic parent material and the progress of soil development. Diffuse reflectance infrared spectroscopy indicated that the composition of particulate soil organic matter was partially affected by CO concentrations: the higher the CO concentrations, the smaller the extent of oxidative transformation and the smaller the abundance of carboxyl groups. In the clay fractions, stabilisation of transformed soil organic matter (SOM) was promoted by exchangeable Al. This study quantifies, for the first time, the correlation between geogenic CO and several inorganic soil properties and the composition of SOM in physical fractions.

Keywords: DRIFT spectroscopy; mofette; stabilisation; weathering.

ISSN: 1838-675X

E-ISSN: 1838-6768

DOI: 10.1071/SR17283

Language: English

In: Journal of Soils and Sediments, Jan, 2012, Vol.12(1), p.3(21)

Description: Byline: Thilo Rennert (1), Kai U. Totsche (1), Katja Heister (2), Michael Kersten (3), Jurgen Thieme (4) Keywords: AFM; Interfaces; uCT; NanoSIMS; Soils; X-ray microscopy Abstract: Purpose Biogeochemical interfaces, the 3D association of minerals, soil organic matter, and biota, are hotspots of soil processes because they exhibit strong biological, physical, and chemical gradients. Biogeochemical interfaces have thicknesses from nanometers to micrometers and separate bulk immobile phases from mobile liquid or gaseous phases. The aim of this contribution is to review advanced microscopic and spectroscopic characterization techniques that allow for spatially resolved analysis of composition and properties of biogeochemical interfaces or their visualization. Materials and methods From the variety of techniques to study biogeochemical interfaces in soil, we focus on X-ray spectromicroscopy, nano-scale secondary ion mass spectrometry, atomic force microscopy, micro-X-ray tomography, and positron emission tomography. Beside an introduction into the respective method, we review published applications and give practical examples. Results and discussion The development of terrestrial soils involves the formation of biogeochemical interfaces as the result of the complex 3D interplay of primary and secondary minerals, soil organic matter together with soil biota. X-ray microscopy allows for the visualization of structures down to range of 10--30 nm and for the determination of binding states of elements. Nano-scale secondary ion mass spectrometry is capable of simultaneously analyzing up to seven secondary ion species to give the elemental and isotopic composition down to 50--150 nm. Atomic force microscopy enables to study the topography and mechanical properties (softness, elasticity, plasticity, deformability) of soil particle surfaces down to the nm scale. X-ray micro-tomography has been shown to visualize the interior of materials at the sub-micrometer scale successfully. Conclusions Introducing and adapting the discussed methods in soil science has increased the understanding of formation, properties, and functioning of biogeochemical interfaces in soil. A further challenging task is to utilize further promising techniques, e.g., advanced Raman techniques or atomic probe tomography with the highest spatial resolution for 3D compositional information of any microscopy technique. Author Affiliation: (1) LS Hydrogeologie, Institut fur Geowissenschaften, Friedrich-Schiller-Universitat Jena, Burgweg 11, 07749, Jena, Germany (2) Lehrstuhl fur Bodenkunde, Technische Universitat Munchen, 85350, Freising-Weihenstephan, Germany (3) Institut fur Geowissenschaften, Johannes-Gutenberg-Universitat Mainz, Becherweg 21, 55099, Mainz, Germany (4) NSLS-II Project, Brookhaven National Laboratory, Upton, NY, 11973, USA Article History: Registration Date: 09/08/2011 Received Date: 01/07/2011 Accepted Date: 09/08/2011 Online Date: 30/08/2011

Keywords: Mass Spectrometry -- Methods ; Soil Carbon -- Methods ; Nanotechnology -- Methods ; Atomic Force Microscopy -- Methods

ISSN: 1439-0108

E-ISSN: 16147480

DOI: 10.1007/s11368-011-0417-5

Language: English

In: Chemical Geology, Jan 10, 2014, Vol.363, p.13(9)

Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chemgeo.2013.10.029 Byline: Thilo Rennert, Karin Eusterhues, Syuntaro Hiradate, Hergen Breitzke, Gerd Buntkowsky, Kai U. Totsche, Tim Mansfeldt Abstract: At 12,900aBP, the eruption of the Laacher See volcano generated a new parent material for Holocene soil formation in parts of Western Germany. Weathering of these ashes commonly includes the formation of poorly crystalline minerals such as allophane, imogolite and ferrihydrite. Detection of these minerals in soil is difficult, yet an important task, because they may govern soil functions and processes, e.g., stabilisation of organic matter and nutrient availability. Therefore, we characterised three forested Andosols by a combination of wet-chemical and spectroscopic techniques including infrared and (.sup.27Al,.sup.29Si) nuclear magnetic resonance (NMR) spectroscopy together with X-ray diffractometry. Deconvoluting the.sup.29Si-NMR spectra revealed that 1.6 to 10.4% of total Si was present as allophanic compounds, which coincided with the amounts of oxalate-extractable Si. Since extraction methods are not completely selective, we observed a slight overestimation of allophanic Si estimated from oxalate extraction. Although the sites under study are located close to each other in similar relief positions and with similar vegetation, the combination of our results revealed varying amounts of loess in the parent materials and varying weathering intensity. High weathering intensities correlate with the amounts of allophane. Article History: Received 12 July 2013; Revised 21 October 2013; Accepted 27 October 2013 Article Note: (miscellaneous) Editor: Carla M. Koretsky

Keywords: Oxalic Acid -- Methods ; Nuclear Magnetic Resonance Spectroscopy -- Methods ; Oxalates -- Methods

ISSN: 0009-2541

Source: Cengage Learning, Inc.

Language: English

In: Chemosphere, May 2016, Vol.150, pp.390-397

Description: Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) combined with a seven steps sequential extraction technique were used to assess the geochemical distribution of chromium (Cr) and lead (Pb) in a contaminated floodplain soil. Total contents of Cr and Pb were 490.3 and 402.1 mg kg , respectively. The residual fraction was 59.5 and 56.3% of total Cr and Pb. The crystalline iron (Fe) oxide was the dominant non-residual fraction of Cr (35.9% of total Cr). Considerable amounts of Pb were found in the organic fraction (35.4%). Using C nuclear magnetic resonance spectroscopy, the soil organic matter was identified as 48.9% aromatic carbon, which indicated that a certain portion of Pb and Cr might be associated with aromatic compounds. The SEM–EDX images demonstrate a concomitant occurrence of Pb, manganese (Mn), Fe, and aluminum (Al) as well as a coexistence of Cr and Fe. The release dynamics of dissolved Cr and Pb as affected by redox potential (E ), pH, Fe, Mn, dissolved organic carbon, and sulfate was quantified using an automated biogeochemical microcosm apparatus. Soil pH decreased under oxic conditions. The release of Cr, Pb, Fe, and Mn increased under acidic oxic (pH = 3.7, E  = 521 mV) conditions due to the associated decrease of pH (7.1–3.7). The mobilization of Cr and Pb was affected by the Fe and Mn. In conclusion, our multi-technique approach identified the geochemical distribution of Cr and Pb and verified major factors that explain mobilization of Cr and Pb in floodplain soils.

Keywords: Toxic Metals ; Mobilization ; Wetlands ; Scanning Electron Microscope Coupled With Energy Dispersive X-Ray Analysis (SEM–Edx) ; Nuclear Magnetic Resonance Spectroscopy (NMR) ; Chemistry ; Ecology

ISSN: 0045-6535

E-ISSN: 1879-1298

DOI: 10.1016/j.chemosphere.2016.02.021

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