14 results on '"Haderlein, S.B"'
Search Results
2. Perspectives of compound-specific isotope analysis of organic contaminants for assessing environmental fate and managing chemical pollution
- Author
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Hofstetter, T.B., Bakkour, R., Buchner, D., Eisenmann, H., Fischer, A., Gehre, Matthias, Haderlein, S.B., Höhener, P., Hunkeler, D., Imfeld, G., Jochmann, M.A., Kümmel, Steffen, Martin, P.R., Pati, S.G., Schmidt, T.C., Vogt, Carsten, Elsner, M., Hofstetter, T.B., Bakkour, R., Buchner, D., Eisenmann, H., Fischer, A., Gehre, Matthias, Haderlein, S.B., Höhener, P., Hunkeler, D., Imfeld, G., Jochmann, M.A., Kümmel, Steffen, Martin, P.R., Pati, S.G., Schmidt, T.C., Vogt, Carsten, and Elsner, M.
- Abstract
The management and mitigation of chemical pollution are key elements of sustainable development initiatives that aim to provide safe and clean water. While environmental scientists are developing the capabilities to assess the fate, (eco)toxicity and risks of a plethora of synthetic chemicals comprehensively, notorious pollution scenarios and decontamination challenges call for targeted and case-specific evaluation of chemical hazards. Here we review the utility and perspectives of compound-specific isotope analysis for obtaining an understanding of environmental processes that allows one to identify pollution sources, assess contaminant (bio)transformation and gain insights into reaction pathways. Using three prototypical scenarios of water contamination, namely point-source pollution of groundwater at contaminated sites, diffuse pollution of soils and surface waters through pesticide use and the abatement of pharmaceuticals and disinfection by-products in water treatment systems, we illustrate both success stories of compound-specific isotope analysis and current developments to address challenges for future applications.
- Published
- 2024
3. A biogeochemical–hydrological framework for the role of redox-active compounds in aquatic systems
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Peiffer, S., Kappler, A., Haderlein, S.B., Schmidt, C., Byrne, J.M., Kleindienst, S., Vogt, Carsten, Richnow, Hans Hermann, Obst, M., Angenent, L.T., Bryce, C., McCammon, C., Planer-Friedrich, B., Peiffer, S., Kappler, A., Haderlein, S.B., Schmidt, C., Byrne, J.M., Kleindienst, S., Vogt, Carsten, Richnow, Hans Hermann, Obst, M., Angenent, L.T., Bryce, C., McCammon, C., and Planer-Friedrich, B.
- Abstract
Redox-driven biogeochemical element cycles play a central role in converting organic matter in aquatic ecosystems. They also perform key functions such as removing nitrate, mitigating the formation of greenhouse gases and weakening the effects of contaminants. Recent research has revealed the presence of redox-active compounds in these ecosystems with hitherto unknown redox properties. These substances are metastable (that is, non-equilibrium solid phases), which can both donate and accept electrons. They are highly redox reactive and recyclable and may act as biogeobatteries by temporarily storing electrons. Their lifetime, however, is limited, and with time they become more crystalline and less reactive. In this Review, we argue that these redox-active metastable phases require activation by fluctuating redox conditions to maintain their high reactivity. In aquatic ecosystems, switching between oxidizing and reducing conditions can be achieved only through hydrological perturbations at hydrological interfaces (for example, water level fluctuations). We present a novel framework that links microscale biogeochemical processes to large-scale hydrological processes, and discuss implications and future research directions for biogeochemical element cycles in aquatic systems exposed to frequent hydrological disturbances.
- Published
- 2021
4. Calibration bias of experimentally determined chlorine isotope enrichment factors: the need for a two-point calibration in compound-specific chlorine isotope analysis
- Author
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Ebert, K.A., Laskov, C., Elsner, M., and Haderlein, S.B.
- Subjects
Csia ,Calibration Schemes ,Chlorinated Ethenes ,Chlorine Isotope Analysis ,Chlorine Isotope Enrichment Factors ,Smoc - Abstract
RATIONALE: The recent development of compound-specific online chlorine isotope analysis ((37) Cl-CSIA) methods has fostered dual chlorine-carbon isotope studies to gain better insights into sources and environmental transformation reactions of chlorinated ethenes (CEs). 1-point and 2-point calibration schemes are currently used to convert raw data to the international δ(37) ClSMOC scale, but a critical evaluation of best practices to arrive at reliable δ(37) ClSMOC signatures and enrichment factors was missing and is presented here. METHODS: Aqueous solutions of neat PCE and TCE and aqueous samples from a TCE biodegradation experiment with pure cultures of Desulfitobacterium hafniense Y51 were analysed for their chlorine isotope ratios using GC/qMS and GC/IRMS. The δ(37) ClSMOC values were obtained using 1-point and 2-point calibration schemes. Chlorine isotope enrichment factors, ɛCl , were calculated using both approaches and the corresponding bias of δ(37) ClSMOC values introduced by the different types of calibration was determined. RESULTS: Different calibration methods resulted in significant differences (up to 30%) in both δ(37) Cl signatures and ɛCl -values. CONCLUSIONS: Our results demonstrate that a 2-point calibration together with comprehensive information on reference materials is indispensable and should become standard practice for reliable (37) Cl-CSIA of organic compounds.
- Published
- 2016
5. Flow through Experiment on CO2-brine-rock Interaction in a Sandstone from the Altmark Gas Reservoir
- Author
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Huq, F., primary, Haderlein, S.B., additional, Cirpka, O.A., additional, Nowak, M., additional, Blum, P., additional, and Grathwohl, P., additional
- Published
- 2015
- Full Text
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6. Response to comment on 'Effects of native organic material and water on sorption properties of reference diesel soot'
- Author
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Endo, Satoshi, Grathwohl, P., Haderlein, S.B., Schmidt, T.C., Endo, Satoshi, Grathwohl, P., Haderlein, S.B., and Schmidt, T.C.
- Abstract
no abstract
- Published
- 2009
7. LFERs for soil organic carbon-water distribution coefficients (KOC) at environmentally relevant sorbate concentrations
- Author
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Endo, Satoshi, Grathwohl, P., Haderlein, S.B., Schmidt, T.C., Endo, Satoshi, Grathwohl, P., Haderlein, S.B., and Schmidt, T.C.
- Abstract
Organic carbon-water distribution coefficients, K-OC, for organic compounds at environmentally relevant, low sorbate concentrations may substantially differ from those at higher concentrations due to nonlinear sorption to soil organic matter. However, prediction methods for K-OC such as linear free energy relationships (LFERs) are currently only available for high sorbate concentrations (i.e., near solubility limits), reflecting the lack of a set of consistent experimental data in an environmentally more relevant concentration range (i.e., orders of magnitude lower than solubilities). In this study, we determined K-OC for two model sorbents of soil organic matter, peat and lignite, at sorbate concentrations of 4.3 and 19 mg/kg-organic-carbon, respectively, in batch suspensions. The measured K-OC values for organic sorbates (51 for peat, 58 for lignite) of varying sizes and polarities were modeled successfully with polyparameter linear free energy relationships (PP-LFERs). The resulting PP-LFER for peat was significantly different from the PP-LFERs in the literature determined at near aqueous solubility limits of sorbates. The literature PP-LFERs were found to underestimate the measured K-OC values for peat at the low concentration by up to 1 order of magnitude. The extent of underestimation highly depends on the sorbate properties and can be explained by differing sorption nonlinearities of the sorbates as predicted by a reported empirical relationship between the nonlinearity in peat and the sorbate dipolarity/polarizability parameter S. Lignite appears to be a stronger sorbent toward many sorbates than typical soil organic matter irrespective of the concentration range and thus may not be representative for organic matter with regard to the magnitude of K-OC. The present study offers the first PIP-LIFER equation for log K-OC in soil organic matter at typical environmental sorbate concentrations
- Published
- 2009
8. Effects of native organic material and water on sorption reference diesel soot
- Author
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Endo, Satoshi, Grathwohl, P., Haderlein, S.B., Schmidt, T.C., Endo, Satoshi, Grathwohl, P., Haderlein, S.B., and Schmidt, T.C.
- Abstract
Soot has been considered as a potentially important sorbent for organic contaminants in soils, sediments, and aerosols. This paper demonstrates that native (authigenic) extractable organic material (EOM) and surface-covering water on soot may have a substantial influence on sorption properties of the soot. Sorption isotherms were determined for apolar and weakly polar sorbates (n-octane, cyclooctane, n-propylbenzene, naphthalene) from an aqueous solution to a standard reference material of diesel soot (SRM 2975) in the original state and after extraction with methanol. For all sorbates tested, removal of EOM from soot by methanol caused the sorption isotherms to be more nonlinear (decrease of Freundlich exponents by 0.19-0.25) compared to the untreated soot. The changes in the isotherms depend on both sorbate structure and sorbate concentration and can be accounted for by two opposing roles that EOM could have on the sorption properties of soot: (i) enhancing the overall sorption by absorbing the sorbate into the EOM phase, and (ii) attenuating the sorbate adsorption to the soot carbon surface through sorption competition or site blockage. The n-alkane-to-cycloalkane sorption coefficient ratios (K-n/K-c) indicated that the removal of EOM altered the sorption mode for alkanes from absorption to adsorption. A comparison of the sorption isotherms measured in aqueous suspensions with the soot-air sorption coefficients reported for SRM 2975 in the literature showed that sorption to "soot in water" is significantly weaker than sorption to "soot in air", indicating that complete surface coverage with water suppresses the sorption by soot.
- Published
- 2009
9. Microbial degradation of methyl tert-butyl ether and tert-butyl alcohol in the subsurface
- Author
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Schmidt, Torsten, Schirmer, Mario, Weiß, Holger, Haderlein, S.B., Schmidt, Torsten, Schirmer, Mario, Weiß, Holger, and Haderlein, S.B.
- Abstract
The fate of fuel oxygenates such as methyl tert-butyl ether (MTBE) in the subsurface is governed by their degradability under various redox conditions. The key intermediate in degradation of MTBE and ethyl tert-butyl ether (ETBE) is tert-butyl alcohol (TBA) which was often found as accumulating intermediate or dead-end product in lab studies using microcosms or isolated cell suspensions. This review discusses in detail the thermodynamics of the degradation processes utilizing various terminal electron acceptors, and the aerobic degradation pathways of MTBE and TBA. It summarizes the present knowledge on MTBE and TBA degradation gained from either microcosm or pure culture studies and emphasizes the potential of compound-specific isotope analysis (CSIA) for identification and quantification of degradation processes of slowly biodegradable pollutants such as MTBE and TBA.Microcosm studies demonstrated that MTBE and TBA may be biodegradable under oxic and nearly all anoxic conditions, although results of various studies are often contradictory, which suggests that site-specific conditions are important parameters. So far, TBA degradation has not been shown under methanogenic conditions and it is currently widely accepted that TBA is a recalcitrant dead-end product of MTBE under these conditions. Reliable in situ degradation rates for MTBE and TBA under various geochemical conditions are not yet available. Furthermore, degradation pathways under anoxic conditions have not yet been elucidated. All pure cultures capable of MTBE or TBA degradation isolated so far use oxygen as terminal electron acceptor.In general, compared with hydrocarbons present in gasoline, fuel oxygenates biodegrade much slower, if at all. The presence of MTBE and related compounds in groundwater therefore frequently limits the use of in situ biodegradation as remediation option at gasoline-contaminated sites. Though degradation of MTBE and TBA in field studies has been reported under oxic conditions
- Published
- 2004
10. Correction to 'Polar fuel constituents: Compound identification and equilibrium partitioning between nonaqueous phase liquids and water (vol 36, pg 4074, 2002)'
- Author
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Schmidt, T.C., Kleinert, P., Stengel, C., Goss, Kai Uwe, Haderlein, S.B., Schmidt, T.C., Kleinert, P., Stengel, C., Goss, Kai Uwe, and Haderlein, S.B.
- Abstract
no abstract
- Published
- 2003
11. Use and occurrence of fuel oxygenates in Europe
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Diaz, A.F., Drogos, D.L., Schmidt, T.C., Morgenroth, E., Schirmer, Mario, Effenberger, Martina, Haderlein, S.B., Diaz, A.F., Drogos, D.L., Schmidt, T.C., Morgenroth, E., Schirmer, Mario, Effenberger, Martina, and Haderlein, S.B.
- Published
- 2002
12. Polar fuel constituents: Compound identification and equilibrium partitioning between nonaqueous phase liquids and water
- Author
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Schmidt, T.C., Kleinert, P., Stengel, C., Goss, Kai Uwe, Haderlein, S.B., Schmidt, T.C., Kleinert, P., Stengel, C., Goss, Kai Uwe, and Haderlein, S.B.
- Abstract
Groundwater contamination by fuel constituents from nonaqueous phase liquids (NAPLs) on top of the groundwater table is a widespread problem. While leaching of classical fuel constituents such as benzene, toluene, ethylbenzene, and xylenes (BTEX) from NAPLs into groundwater has been studied extensively, little is known about the identity and partitioning of polar fuel components. Our work shows that gasoline commonly contains appreciable amounts of aniline, phenol, and their alkyl-substituted homologues as well as a suite of other polar compounds. To assess the potential for leaching of such compounds from NAPLs into groundwater we measured the equilibrium fuel/water partitioning coefficients, K-fw, of some representative constituents in batch systems. K-fw values for the investigated phenols, anilines, benzotriazoles, and S-heterocycles ranged from 0.2 to 1700. These values are up to 3 orders of magnitude lower than the K-fw of benzene. The NAPL-water partitioning of anilines and phenols strongly depends on the compounds' structure as well as on pH and the gasoline composition (e.g., MTBE content). Linear free energy relationships (LFERs) using K-ow or C-w(sat) failed to predict measured K-fw values of polar solutes. In contrast, a polyparameter approach taking into account molecular interactions (van der Waals forces, hydrogen bonds) between solutes and major gasoline components allows precise a-priori predictions of K-fw values of both polar and BTEX fuel constituents without any fit parameters. Since most of the polar fuel constituents studied here are extracted from NAPLs by groundwater much more efficiently than BTEX, such compounds could form contaminant plumes threatening receiving wells before detectable concentrations of BTEX are present.
- Published
- 2002
13. MTBE oxidation by conventional ozonation and the combination ozone/hydrogen peroxide: Efficiency of the processes and bromate formation
- Author
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Acero, J.L., Haderlein, S.B., Schmidt, T.C., Suter, M.J.F., and Von Gunten, U.
- Subjects
Dilute Aqueous-Solution ,Ozone ,Hydrogen-Peroxide ,Uv/H2O2 Process ,Rate Constants ,Hydroxyl Radicals ,Sonolytic Destruction ,Bromide-Containing Waters ,Ultrasonic Irradiation ,Tert-Butyl Ether - Abstract
The present study investigates the oxidation of methyl tert-butyl ether (MTBE) by conventional ozonation and the advanced oxidation process (AOP) ozone/hydrogen peroxide under drinking water treatment conditions. The major degradation products identified were tert-butyl formate (TBF), tert-butyl alcohol (TBA), 2-methoxy-2-methyl propionaldehyde (MMP), acetone (AC), methyl acetate (MA), hydroxyisobutyraldehyde (HiBA), and formaldehyde (FA). The rate constants of the reaction of ozone and OH radicals with MTBE were found to be 0.14 and 1.9 x 10(9) M-1 s(-1), respectively. The rate constants for the same oxidation processes were also measured fort he degradation products TBF, MMP, MA, and HiBA (k(O3-TBF) = 0.78 M-1 S-1; k(OH-TBF) = 7.0 x 10(8) M-1 s(-1); k(O3-MMP) = 5 M-1 s(-1); k(OH-MMP) = 3 x 10(9) M-1 s(-1), k(O3-MA) = 0.09 M-1 s(-1), k(O3- HiBA) = 5 M-1 s(-1); k(OH-HiBA) = 3 x 10(9) M-1 s(-1)). Since all compounds reacted slowly with molecular ozone only the degradation pathway of MTBE with OH radicals as been determined, including the formation of primary degradation products. In experiments performed with several natural waters, the efficiency of MTBE elimination and the formation of bromate as disinfection byproduct have been measured. With a bromide level of 50 mug/L, only 35-50% of MTBE could be eliminated by the AOP O-3/ H2O2 without exceeding the current drinking water standard of bromate (10 mug/L). The transient concentrations of MTBE and its primary degradation products were modeled using a combination of kinetic parameters (degradation product distribution and rate constants) together with the ozone and OH radical concentration and were in good agreement with the experimental results.
14. Compound-Specific Chlorine Isotope Analysis: A Comparison of Gas Chromatography/Isotope Ratio Mass Spectrometry and Gas Chromatography/Quadrupole Mass Spectrometry Methods in an Interlaboratory Study
- Author
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Bernstein, A, Shouakar-Stash, O, Ebert, K, Laskov, C, Hunkeler, Daniel, Jeannottat, Simon, Sakaguchi-Söder, K, Laaks, J, Jochmann, M.A, Cretnik, S, Jager, J, Haderlein, S.B, Schmidt, T.C, Aravena, R, Elsner, M, Bernstein, A, Shouakar-Stash, O, Ebert, K, Laskov, C, Hunkeler, Daniel, Jeannottat, Simon, Sakaguchi-Söder, K, Laaks, J, Jochmann, M.A, Cretnik, S, Jager, J, Haderlein, S.B, Schmidt, T.C, Aravena, R, and Elsner, M
- Abstract
Chlorine isotope analysis of chlorinated hydrocarbons like trichloroethylene (TCE) is of emerging demand because these species are important environmental pollutants. Continuous flow analysis of noncombusted TCE molecules, either by gas chromatography/isotope ratio mass spectrometry (GC/IRMS) or by GC/quadrupole mass spectrometry (GC/qMS), was recently brought forward as innovative analytical solution. Despite early implementations, a benchmark for routine applications has been missing. This study systematically compared the performance of GC/qMS versus GC/IRMS in six laboratories involving eight different instruments (GC/IRMS, Isoprime and Thermo MAT-253; GC/qMS, Agilent 5973N, two Agilent 5975C, two Thermo DSQII, and one Thermo DSQI). Calibrations of 37Cl/35 Cl instrument data against the international SMOC scale (Standard Mean Ocean Chloride) deviated between instruments and over time. Therefore, at least two calibration standards are required to obtain true differences between samples. Amount dependency of δ37Cl was pronounced for some instruments, but could be eliminated by corrections, or by adjusting amplitudes of standards and samples. Precision decreased in the order GC/IRMS (1σ ≈ 0.1%), to GC/qMS (1σ ≈0.2_0.5%for Agilent GC/qMS and 1σ≈0.2_0.9%for Thermo GC/qMS). Nonetheless, δ37Cl values between laboratories showed good agreement when the same external standards were used. These results lend confidence to the methods and may serve as a benchmark for future applications.
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