A5070738531- Wastewater Treatment and Nitrogen Removal
- Geophysical and Geoelectrical Methods
- Microbial Community Ecology and Physiology
- Microbial Fuel Cells and Bioremediation
- Geochemistry and Geologic Mapping
- Groundwater flow and contamination studies
- Electrokinetic Soil Remediation Techniques
- Pharmaceutical and Antibiotic Environmental Impacts
- Advanced Chemical Sensor Technologies
- CO2 Sequestration and Geologic Interactions
- Chromium effects and bioremediation
- NMR spectroscopy and applications
- Methane Hydrates and Related Phenomena
- Seismic Waves and Analysis
- Fish Ecology and Management Studies
- Earthquake Detection and Analysis
- Gut microbiota and health
- Soil and Unsaturated Flow
- Soil and Water Nutrient Dynamics
- Mine drainage and remediation techniques
- Isotope Analysis in Ecology
- Environmental remediation with nanomaterials
- Biofield Effects and Biophysics
- Soil Carbon and Nitrogen Dynamics
- Plant and Biological Electrophysiology Studies
University of Kassel
2022-2025
Norsk Hydro (Sweden)
2025
University of Tübingen
2015-2023
University of Waterloo
2015-2020
Science and Technology on Surface Physics and Chemistry Laboratory
2019
Redox-active organic molecules such as anthraquinone-2,6-disulfonate (AQDS) and natural matter (NOM) can act electron shuttles thus facilitating transfer from Fe(III)-reducing bacteria (FeRB) to terminal acceptors Fe(III) minerals. In this research, we examined the length scale over which shuttling occur. We present results agar-solidified experimental incubations, containing either AQDS or NOM, where FeRB were physically separated ferrihydrite goethite by 2 cm. Iron speciation concentration...
Abstract Spectral induced polarization (SIP) can provide valuable information about (bio)geochemical processes taking place in the poorly accessible subsurface. The method is sensitive to reactions that alter solid‐water interface. Here, we critically evaluate effectiveness of SIP monitor geochemical by focusing on a model‐supported analysis cation exchange dynamics sediments containing organic matter. Organic matter crucial substrate for contaminant immobilization exhibits strong response....
ABSTRACT This paper provides an update on the fast‐evolving field of induced polarization method applied to biogeophysics. It emphasizes recent advances in understanding signals stemming from biological materials and their activity, points out new developments applications, identifies existing knowledge gaps. The focus this review is application study living organisms: soil microorganisms plants (both roots stems). We first discuss observed links between signal microbial cell structure,...
Geophysical techniques, such as spectral induced polarization (SIP), offer potentially powerful approaches for in situ monitoring of subsurface biogeochemistry. The successful implementation these techniques tools reactive transport phenomena, however, requires the deconvolution multiple contributions to measured signals. Here, we present SIP spectra and complementary biogeochemical data obtained saturated columns packed with alternating layers ferrihydrite-coated pure quartz sand,...
Neutrophilic microbial pyrite (FeS2) oxidation coupled to denitrification is thought be an important natural nitrate attenuation pathway in nitrate-contaminated aquifers. However, the poor solubility of raises questions about its bioavailability and mechanisms underlying oxidation. Here, we investigated direct by a neutrophilic chemolithoautotrophic nitrate-reducing Fe(II)-oxidizing culture enriched from pyrite-rich aquifer. We used with abundance (NA) Fe isotopes (NAFe-pyrite) 57Fe-labeled...
Abstract Spectral Induced Polarization (SIP) has been suggested as a non‐invasive monitoring proxy for microbial processes. Under natural conditions, however, multiple and often coupled polarization processes co‐occur, impeding the interpretation of SIP signals. In this study, we analyze sensitivity to microbially‐driven reactions under quasi‐natural conditions. We conducted flow‐through experiments in columns equipped with electrodes filled calcareous, organic‐carbon‐rich aquifer sediment,...
Monitoring the extent of heavy metal remediation on reactive materials employed in schemes relies downflow concentration sampling. The latter implies that a decreasing barrier efficiency only becomes apparent once contaminant breakthrough has occurred and thus contamination past barrier. Spectral induced polarization (SIP), noninvasive geophysical technique sensitive to sorption-induced changes surface charging properties mineral surfaces porous media, offers potentially powerful monitoring...
Aquifer sediments, formed under varying depositional conditions, exhibit significant heterogeneity in their sedimentary architecture causing variability hydraulic and biogeochemical properties. The spatial arrangement of these properties controls the net turnover biogeochemically reactive environmentally relevant solutes floodplains. However, interlinkage between is still enigmatic. This study proposes using facies analyses to reconstruct paleoenvironmental conditions that control abundance...
Nitrate pollution of groundwater represents a critical environmental concern, with many aquifers exceeding ecological and health-related concentration limits. Microbial driven denitrification the primary mechanism for nitrate attenuation in aquifers. Despite robust understanding individual transformation steps, predicting turnover complex heterogeneous subsurface environment remains challenging. This is primarily due to uneven distribution potential electron donors (e.g., organic carbon)...
Organic contaminant degradation by suspended bacteria in chemostats has shown that isotope fractionation decreases dramatically when pollutant concentrations fall below the (half-saturation) Monod constant. This masked implies membrane transfer is slow relative to enzyme turnover at μg L–1 substrate levels. Analogous evidence of mass as a bottleneck for biodegradation aquifer settings, where microbes are attached sediment, lacking. A quasi-two-dimensional flow-through sediment microcosm/tank...
Autotrophic NRFeOx microorganisms that oxidize Fe(II), reduce nitrate, and produce biomass play a key role in carbon, iron, nitrogen cycles pH-neutral, anoxic environments. Electrons from Fe(II) oxidation are used for the reduction of both carbon dioxide nitrate.
The development of nanoparticle-based soil remediation techniques is hindered by the lack accurate in situ nanoparticle (NP) monitoring and characterization methods. Spectral induced polarization (SIP), a noninvasive geophysical technique, offers promising approach to detect quantify NPs porous media. However, its successful implementation as tool requires an understanding mechanisms, governing NP-associated SIP responses their dependence on stabilizing coatings that are typically used for...
The microbially mediated reactions, that are responsible for field-scale natural attenuation of organic pollutants, governed by the concurrent presence a degrading microbial community, suitable energy and carbon sources, electron acceptors, as well nutrients. temporal lack one these essential components activity, arising from transient environmental conditions, might potentially impair in situ biodegradation. This study presents results small scale flow-through experiments aimed at...
Abstract Water table fluctuations generate temporally and spatially dynamic physicochemical conditions that drive biogeochemical hot spots moments in the vadose zone. However, their role cycling of soil C remains poorly known. Here, we present results from unvegetated column experiments filled with 45 cm artificial containing 10% humus, inoculated a natural microbial extract. In one series three replicate columns, five cycles, each consisting 4‐wk drainage followed by imbibition period, were...
SUMMARY Quantifying the capacity of soils to immobilize sorbing contaminants concern relies on batch sorption experiments, typically performed at skewed solid-to-liquid ratios. The geophysical method spectral induced polarization (SIP) provides a powerful non-invasive monitoring alternative that can capture changes in soil electrical properties driven by contaminant sorption, yielding an approach whereby immobilization be monitored situ. Here, we present SIP signals obtained from series...
Environmental omics and molecular-biological data have been proposed to yield improved quantitative predictions of biogeochemical processes. The abundances functional genes transcripts relate the number cells activity microorganisms. However, whether can be quantitatively linked reaction rates remains an open question. We present enzyme-based denitrification model that simulates concentrations transcription factors, functional-gene transcripts, enzymes, solutes. calibrated using experimental...
Abstract Molecular‐biological data and omics tools have increasingly been used to characterize microorganisms responsible for the turnover of reactive compounds in environment, such as reactive‐nitrogen species groundwater. While transcripts functional genes enzymes are measures microbial activity, it is not yet clear how they quantitatively related actual rates under variable environmental conditions. As an example application, we consider interface between rivers groundwater which has...
ABSTRACT Spectral induced polarization signatures have been used as proxies for microbial abundance in subsurface environments, by taking advantage of the charged properties cell membranes. The method's applicability, however, remains qualitative, and signal interpretation ambiguous. adoption spectral a robust geo‐microbiological tool monitoring dynamics porous media requires development quantitative relationships between biogeochemical targets parameters, such biomass density imaginary...
Abstract Solid organic matter (OM) is a biogeochemically relevant constituent of soils and sediments. It also affects sediments' geophysical properties, but often overlooked in hydro‐ biogeophysical approaches for the characterization shallow subsurface. Here, we explore potential spectral induced polarization (SIP) to delineate OM‐rich zones subsurface provide insights into mechanisms that drive OM‐polarization using measurements on both field cores artificial OM‐sand mixtures. Both,...
Glyphosate, an ionizable organic herbicide, is frequently detected in soils and groundwater globally despite its strong retention via sorption. Understanding apparent mobility hinges on our ability to quantify system-specific sorption behavior, hindered by affinity adsorb onto sediments, yielding very low aqueous concentrations. Here, we present findings from a saturated flow-through column experiment which monitored glyphosate natural calcareous aquifer sediment, using the noninvasive...