Scott Fendorf

The Role of Microenvironments and Physicochemical Subsurface Components on Field Scale Biogeochemistry and Contaminant Mobility

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James McKinley

Project type

Exploratory Research

This is a renewal proposal for a previous collaborative effort between the PNNL Scientific Focus Area (SFA) and EMSL. The research proposed will resolve critical Hanford and basic subsurface science…

Role of Microenvironments and Transition Zones in Subsurface Reactive Contaminant Transport

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James McKinley

This is a renewal proposal for a previous collaborative effort between the PNNL Scientific Focus Area (SFA) and EMSL. The research proposed will resolve critical Hanford and basic subsurface science…

Influence of organic carbon on molecular-scale biogeochemical cycling of iron, sulfur, and uranium in organic-rich aquifer sediments

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

John Bargar

Project type

Large-Scale EMSL Research

We propose a SLAC-EMSL collaboration to study the biogeochemical coupling of subsurface natural organic matter (NOM) to iron, sulfur, and uranium redox cycles in the subsurface at the DOE-BER funded…

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…

Characterization of novel arsenic-iron precipitates formed during biological iron reduction

Lead Institution

Colorado State University

Principal Investigator

Thomas Borch

Project type

Exploratory Research

Arsenic (As) is a priority pollutant, the fate of which is in part controlled by reactions with ferrous iron. Ferrous iron is capable of mediating solid phase transformations of soil and sediment…

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…

Evolution of Fe(II) Mineralization Under Hydrodynamic Conditions Induced by Dissimilatory Iron-Reducing Bacteria

Lead Institution

Woods Hole Oceanographic Institution

Principal Investigator

Colleen Hansel

Project type

Exploratory Research

The reducing capacity of soils and sediments for contaminants will be dictated, in part, by the Fe(II) bearing solids produced by dissimilatory iron reducing bacteria (DIRB). A primary factor…

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…

Mechanisms of Fe Biomineralization Induced By Dissimilatory Iron Reduction

Lead Institution

Woods Hole Oceanographic Institution

Principal Investigator

Colleen Hansel

Project type

Exploratory Research

Iron minerals are ubiquitous in nature and play a critical role in the geochemical cycling of trace elements. In particular, iron oxides serve as potent sorbents and repositories for nutrients and…

Biogeochemical controls exerted by organic-rich sediments on carbon cycling and uranium mobility

Lead Institution

Environmental Molecular Sciences Laboratory

Principal Investigator

John Bargar

Project type

Large-Scale EMSL Research

Floodplains are hydrologically and biogeochemically dynamic environments that store extensive quantities of carbon, host diverse ecosystems, and serve as interfaces for nutrient and contaminant…

Mechanisms of Fe Biomineralization Induced By Dissimilatory Iron Reduction

Lead Institution

Woods Hole Oceanographic Institution

Principal Investigator

Colleen Hansel

Project type

Exploratory Research

Iron minerals are ubiquitous in nature and play a critical role in the geochemical cycling of trace elements. In particular, iron oxides serve as potent sorbents and repositories for nutrients and…

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…

Microscopic Mass Transfer of U and Tc in Subsurface Sediments

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

Chongxuan Liu

Project type

Exploratory Research

This project will investigate microscopic mass transfer process and its influence on and coupling with geochemical and biogeochemical reactions in subsurface sediments. The research will focus on…

Influence of rhizosphere processes on biogeochemical cycles governing metal contaminant mobility in floodplains

Lead Institution

Stanford Linear Accelerator Center

Principal Investigator

Kristin Boye

Project type

Large-Scale EMSL Research

Floodplains are important repositories for metals, regulating their transport to surface and groundwater. The heterogeneous lithology and seasonal wet-dry cycling associated with alluvial deposits,…

Role of Microenvironments and Transition Zones in Subsurface Reactive Contaminant Transport

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James McKinley

Project type

Exploratory Research

The PNNL Scientific Focus Area (SFA) will resolve critical Hanford and basic subsurface science issues through integrated, multi-disciplinary, science-theme focused research on the role 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…

Particle size, Associations, and Crystallinity of Bioreduced Uranium phases

Lead Institution

Stanford University

Principal Investigator

Scott Fendorf

Project type

Exploratory Research

Due to mining and nuclear-production activities, uranium is an environmental contaminant of great concern; within surface and subsurface environments, uranium predominates in either the (VI) or (IV)…

Microbial metabolic activity and biogeochemical reaction networks in redox cycled alluvial systems

Lead Institution

Stanford Linear Accelerator Center

Principal Investigator

Kristin Boye

Project type

FICUS Research

Redox conditions and related switches in microbial metabolic activities exert primary control over the stability of carbon, nutrient, and contaminant stocks in alluvial systems, such as floodplains…

Transformation Mechanisms and Kinetics of Fe-(oxyhydr)oxide Reduction and their Impact on Uranium Sequestration

Lead Institution

Stanford Linear Accelerator Center

Principal Investigator

Juan Lezama Pacheco

Project type

Large-Scale EMSL Research

Redox cycling of Fe-(oxyhydr)oxides such as ferrihydrite in naturally or artificially reduced sediments has a major impact on the speciation and stability of uranium. Ferrihydrite is a poorly…

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…

Role of Microenvironments and Transition Zones in Field scale microbial ecology and biogeochemistry

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James McKinley

Project type

Exploratory Research

This is a renewal proposal for a previous collaborative effort between the PNNL Scientific Focus Area (SFA) and EMSL. The research proposed will resolve critical Hanford and basic subsurface science…

Role of Microenvironments and Transition Zones in Field Scale Microbial Ecology and Biogeochemistry

Lead Institution

Pacific Northwest National Laboratory

Principal Investigator

James McKinley

Project type

Limited Scope

This is a renewal proposal for a previous collaborative effort between the PNNL Scientific Focus Area (SFA) and EMSL. The research proposed will resolve critical Hanford and basic subsurface science…

Projects