Marco Keiluweit

Redox controls on uranium mobility: the role of natural organic matter transformations

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

John Bargar

Project type

Special Science

Natural organic matter (NOM) profoundly influences the cycles of metals in the subsurface in its role as electron donor for bacteria and as a complexing agent. In the proposed work, we investigate…

X-ray computed tomography to incorporate redox conditions into soil carbon turnover models

Lead Institution

Oregon State University

Principal Investigator

Markus Kleber

Project type

Limited Scope

We propose to parameterize the tendency of a given soil structure (structure = the combination of diffusive domains and the surrounding spatial void pattern within a given soil volume, Figure 1) to…

Impact of natural organic matter on U speciation and mobility in groundwater

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

John Bargar

Project type

Exploratory Research

Uranium (U) contamination of aquifers is a persistent problem at DOE legacy ore processing sites and, contrary to initial predictions, many plumes are not attenuating with natural groundwater…

X-ray tomography to incorporate redox conditions into soil carbon turnover models

Lead Institution

Oregon State University

Principal Investigator

Markus Kleber

Project type

Exploratory Research

We suggest that X-ray tomography can be successfully employed to generate numerical values of a) total pore space, b) pore geometry, c) pore size distribution and d) pore connectivity at relevant…

The Role of Anaerobic Microsites in Soil Carbon Storage

Lead Institution

Stanford University

Principal Investigator

Scott Fendorf

Project type

Large-Scale EMSL Research

The overarching goal of this project is to quantitatively place the importance of metabolic constraints in anaerobic microsites on the rate of soil organic matter (OM) oxidation, and thus advance our…

Molecular mechanisms underlying changes in the temperature sensitive respiration response of forest soils to long-term experimental warming

Lead Institution

University of Massachusetts Amherst

Principal Investigator

Jeffrey Blanchard

Project type

FICUS Research

A more complete understanding of how global warming will affect carbon-cycle feedbacks to the climate system is central to model projections of future climate. Simulation experiments with fully…

Metabolic Constraints on Organic Matter Decomposition and Metal Cycling in Sediment Deposits

Lead Institution

Stanford University

Principal Investigator

Scott Fendorf

Project type

FICUS Research

Depositional environments such as floodplains are poorly understood and dynamic components of the global carbon cycle that not are well represented in Earth system models. Further, they have a…

The Root of the Matter: Soil Carbon Mobilization in the Rhizosphere

Lead Institution

University of Massachusetts Amherst

Principal Investigator

Marco Keiluweit

Project type

Large-Scale EMSL Research

The exploratory work we propose aims to improve mechanistic understanding of links among rhizodeposition of organic compounds by plant roots, microbial growth and activity, and the strength of…

Spatiotemporal Controls on Organic Matter Availability and Decomposition Rates across Floodplain Sediments

Lead Institution

Stanford University

Principal Investigator

Scott Fendorf

Project type

Large-Scale EMSL Research

Although depositional environments such as floodplains are key regulators of ecosystem carbon storage and downstream metal loadings, they are not very well represented in earth system models…

Deciphering controls on metal migration within floodplains: The critical role of redox environments on metal-organic complexes

Lead Institution

Stanford University

Principal Investigator

Scott Fendorf

Project type

Large-Scale EMSL Research

Dissolved organic matter (DOM) is a major but poorly understood control over the mobility of micronutrient and contaminant metals in surface and subsurface systems. Variations in the chemical…

Sticky Roots -- Implications of Altered Rhizodeposition for the Fate of Mineral-associated Organic Matter in Natural Ecosystems

Lead Institution

University of Massachusetts Amherst

Principal Investigator

Marco Keiluweit

Project type

Large-Scale EMSL Research

The proposed research aims to improve mechanistic understanding of links among rhizodeposition of reactive organic compounds by plant roots, microbial activity, and the stability of mineral…

EMSL Science Overview

Marco Keiluweit

Projects

Redox controls on uranium mobility: the role of natural organic matter transformations

X-ray computed tomography to incorporate redox conditions into soil carbon turnover models

Impact of natural organic matter on U speciation and mobility in groundwater

X-ray tomography to incorporate redox conditions into soil carbon turnover models

The Role of Anaerobic Microsites in Soil Carbon Storage

Molecular mechanisms underlying changes in the temperature sensitive respiration response of forest soils to long-term experimental warming

Metabolic Constraints on Organic Matter Decomposition and Metal Cycling in Sediment Deposits

The Root of the Matter: Soil Carbon Mobilization in the Rhizosphere

Spatiotemporal Controls on Organic Matter Availability and Decomposition Rates across Floodplain Sediments

Deciphering controls on metal migration within floodplains: The critical role of redox environments on metal-organic complexes

Sticky Roots -- Implications of Altered Rhizodeposition for the Fate of Mineral-associated Organic Matter in Natural Ecosystems