Use of Boron-Doped Diamond Electrodes for Treatment of Perfluorinated Compounds
C Higgins (PI at Mines), C Schaefer (PI, Shaw Environmental), US Air Force, October 2011 – August 2013
Treatment of perfluorinated compounds (PFCs) in groundwater poses a significant challenge to the Air Force due to their introduction into the subsurface from the use of aqueous film forming foams (AFFFS) at fire training facilities. Conventional (e.g., carbon sorption) and innovative (advanced oxidation) remedial technologies have been shown to have limited effectiveness for treating PFC contaminated water. Electrochemical treatment of PFCs in groundwater using boron-doped diamond (BDD) electrodes shows great promise as a potential cost-effective remedy for PFC-impacted plumes. The overall goal of this project is to verify and assess treatment of PFCs in groundwater from a well characterized site using a BDD electrochemical treatment system. Specifically, both the rate and extent of PFC treatment will be measured, and potential accumulation of any harmful daughter products will be evaluated. The effectiveness of the BDD electrochemical treatment approach will be assessed in terms of energy consumption (to evaluate the economic feasibility of the technology) and in terms of electrode longevity. The rate of hydrogen generation from the electrochemical treatment also will be measured to determine the potential for energy recovery by means of a hydrogen fuel cell.
Collaborative Research: Biological Controls on Reactive Oxygen Species in the Oligotrophic Ocean
B Voelker (PI at Mines) with C Hansel (PI at Woods Hole Oceanographic Institution), National Science Foundation (NSF), September 2011 – August 2014
Ambient levels of the reactive oxygen species hydrogen peroxide can affect the growth of the most abundant photosynthesizer in the oligotrophic ocean, prochlorococcus. In addition, the reactive oxygen species superoxide can change the oxidation state of biologically important metal ions. The goal of this work is to determine the extent to which biological production and destruction of hydrogen peroxide and superoxide are significant, and which organisms are responsible for these processes.
PAH Interactions with Soil and Effects on Bioaccessibility and Bioavailability to Humans
AL Bunge (PI at Mines), Y Lowney (Exponent Inc.) and M Ruby (Integral Inc) co-PIs, Strategic Environmental Research and Development Program (SERDP) through a subcontractor to Exponent, March 2011-March 2013.
The goal of this task of the larger SERDP project is to generate meaningful data regarding the dermal absorption of PAHs that have been identified as risk drivers in soils at DoD sites, and to investigate the influence of soil characteristics and the source of contamination on skin permeation.
Collaborative Research: Biological Production of Reactive Oxygen Species in Freshwater
B Voelker (PI at Mines) with C Hansel (PI at Woods Hole Oceanographic Institution), National Science Foundation (NSF), September 2010 – August 2013
Reactive oxygen species (ROS) can break down organic contaminants and change the speciation of both toxic and nutrient metals. A main goal of the Mines portion of this collaborative study is to determine the extent to which biological production of ROS contributes to these processes.
Using Molecular Modeling to Determine Structure and Organization in Skin Lipids
C McCabe (PI, Vanderbilt University) and AL Bunge (co-PI and PI at Mines on subcontract to Vanderbilt University), National Institutes of Health (NIH), April 2010-March 2013
The goal is to perform molecular modeling studies using both atomistically detailed and coarse-grained models of the lipids in the stratum corneum (free fatty acids, ceramides, and cholesterol) to probe the molecular arrangement of the lipid molecules and their self-assembly into lamellae. Simulations (molecular dynamics and Monte Carlo) will be performed to analyze the nano-scale structures that are formed and the interactions that drive the self-assembly process. Transport of topical agents, including water, in the SC lipids and their effect on lipid organization will also be studied.
Detection of Engineered Nanomaterials in Drinking Water, Food, Commercial Products, and Biological Samples
JF Ranville (PI), Christopher Higgins (Co-PI), National Institute of Environmental Health Sciences (NIEHS), (Subcontractor to Arizona State University), October 2009-August 2011.
Methods are to be developed to allow the extraction and quantification of TiO2 and ZnO nanoparticles in a number of complex matrices that are relevant to human health concerns. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Using Pulsed-Field Gradient Spin-Echo NMR to Determine Permeation Mechanisms in Human Stratum Corneum
AL Bunge (PI), National Science Foundation (NSF), July 2009-June 2013.
The aim of is to use pulsed-field gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) to study diffusion of a model lipophilic chemical and water within the outermost layer of human skin called the stratum corneum. Human stratum corneum is a multi-phasic membrane consisting of layers of flattened, dead skin cells filled with keratin surrounded by a lipid phase organized into thin layers. The project will demonstrate a new capability for using PGSE-NMR to measure diffusion of chemicals other than water in the stratum corneum (which is the rate-limiting barrier for chemical permeation through skin) and to ascertain the location within the stratum corneum of the PGSE-NMR diffusion measurements.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Characterization of Metal-Containing Nanoparticles Using FFF-ICP-MS
JF Ranville (PI), US Army Corp of Engineers (USACE), April 2009-December 2012.
Methods are being developed to examine the ecological exposure of terrestrial organisms to nano-Ag and quantum dots. Nanoparticles will be enumerated using novel ICP-MS methods including FFF-ICP-MS and real time single particle ICP-MS (RTSP-ICP-MS).
Aquatic Toxicity Testing for the Development of a Mixed Metal Biotic Ligand Model
JF Ranville (PI), Copper Development Corporation, June 2009-December 2009.
Toxicity testing of mixtures of metals (Cu, Zn, Ag, Cd) is being performed using D. magna. Results are being investigated to determine if the affects are: synergistic, additive, or antagonistic. Results will be used to more fully parameterize the biotic ligand model, a computational approach to assessing aquatic toxicity of cationic metals.
Evaluation of Constructed Wetlands for the Removal of Metals from AMD
JF Ranville (PI), US Environmental Protection Agency (USEPA), Region VIII, March 2009-December 2009.
The removal of metals from a constructed wetland that receives both acid mine drainage and treated municipal wastewater is being investigated. Mechanisms being examined include: phyto-uptake, sorption to metal oxides, and precipitation. Ecotoxicological endpoints that are under investigation include: bioaccumulation, feeding rate, and mortality.
A Novel Sensor for the In Situ Measurement of Uranium Fluxes
JF Ranville (PI), Department of Energy, Environmental Remediation Sciences Program (DOE-ERSP) (Subcontractor to University of Florida), May 2008-April 2011.
The project goal was to develop a sensor for measuring uranium flux in groundwater. The application is for the risk assessment of the Rifle, Colorado DOE study site.
Assessment and Treatment of the Young-Dong Coal Mine
JF Ranville (PI), MIRECO, May 2008-December 2008
In this project the environmental impact of a coal mine in South Korea was assessed. As part of the project a design for a passive treatment system was prepared.
Development of a Guidance Document for Estimating Dermal Absorption from Contaminated Soils
AL Bunge (PI), Environmental Protection Agency (EPA), April 2008-January 2009
A guidance document was written describing how to estimate dermal absorption from contaminated soils, based upon the current knowledge and new research results produced at Colorado School of Mines.
In Situ Examination of Hydrogen Peroxide Sources and Sinks in a Slightly Alkaline Stream
B Voelker (PI at Mines), National Science Foundation (NSF) Collaborative Research, September 2007-August 2010
Hydrogen peroxide may be the most important source of hydroxyl radical in surface waters via Fenton’s reaction – reduction of hydrogen peroxide by Fe(II). Oxidation by hydroxyl radical is an effective mechanism for converting refractory organic compounds, including contaminants and natural organic matter, to CO2 and microbial substrates. The overall goal of the proposed work was to conduct the first comprehensive study of hydrogen peroxide cycling in a natural stream. Our results will show whether hydroxyl radical production from hydrogen peroxide could be a dominant mechanism of indirect photolysis of organic contaminants and natural organic matter in streams. Our work could also lay the groundwork for developing methods to accelerate Fenton’s reaction in systems such as agricultural headwaters, for the purpose of decreasing concentrations of contaminants such as atrazine.
Molecular Modeling of Self-Assembling Human Skin Lipids
AL Bunge (co-PI and PI at Mines) with C McCabe (PI, University of Vanderbilt), National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), August 2007-July 2010
The ultimate goal was to develop a basic understanding of how and why skin lipids assemble into specific structures and how this affects skin barrier function. The approach was to simulate lipids in the stratum corneum, which consist mainly of ceramides, cholesterol and fatty acids.
Relating Pore-Scale Uranium (VI) Aquatic Speciation to Intermediate-Scale Aquifer Heterogeneity: Determining pH-Dependant Uranium-Nanoparticle Partitioning in Small-Volume Porewater Samples
JF Ranville (PI), Department of Energy, Environmental Remediation Sciences Program (DOE-ERSP), June 2007-May 2010
The project was to develop Field flow fractionation-ICP-MS methods to determine the in-situ speciation of uranium in groundwater. This is part of a larger risk-assessment project for contaminated groundwaters at Rifle, Colorado.
Nanoparticle Stability in Natural Waters and Its Implication for Metal Toxicity to Water Column and Benthic Organisms
JF Ranville (PI), US Environmental Protection Agency, Science to Achieve Results (USEPA-STAR), April 2007-April 2010.
The aquatic toxicity of quantum dots was examined. The stability of quantum dots in natural waters and the development of detection techniques for nanoparticles at low concentration were also investigated.
Critical Evaluation of Hydrodynamic and Geochemical Parameters Affecting Contaminant Migration
JF Ranville (PI), Battelle Memorial Institute, January 2007-February 2009
The ecological risk of pharmaceuticals applied to soil was assessed by examining the adsorption of the target compounds to soil particles.
Superoxide Radical Reactions in the Ocean
B Voelker (PI), National Science Foundation, February 2006-January 2009
Superoxide radical is of interest to marine chemists because of its ability to reduce and/or oxidize metals. These reactions can potentially change the environmental fate and bioavailability of either toxic metals, such as copper or mercury, or nutrient metals such as Fe. The main goals of this research were to determine whether there is enough superoxide in the open ocean to have significant effects on metal speciation, and to identify superoxide’s main sources and sinks.
Dermal Absorption of Chemicals from Liquid Mixtures
AL Bunge (PI), National Institute of Occupational Safety and Health (NIOSH), September 2004-March 2009
The goal of this research effort was to provide occupational safety and health practitioners with improved guidance regarding potentially dangerous levels of occupational dermal exposure.