A5081606313- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Mine drainage and remediation techniques
- Heavy metals in environment
- Chromium effects and bioremediation
- Geochemistry and Elemental Analysis
- Metal complexes synthesis and properties
- Groundwater flow and contamination studies
- Metal Extraction and Bioleaching
- Radioactive element chemistry and processing
- Mercury impact and mitigation studies
- Groundwater and Isotope Geochemistry
- Synthesis and Characterization of Heterocyclic Compounds
- Industrial Engineering and Technologies
- Heavy Metal Exposure and Toxicity
- Electrokinetic Soil Remediation Techniques
- Arsenic contamination and mitigation
- Microfluidic and Bio-sensing Technologies
- Minerals Flotation and Separation Techniques
- Seismic Imaging and Inversion Techniques
- Magnetism in coordination complexes
- Enhanced Oil Recovery Techniques
- Crystal structures of chemical compounds
- Microbial Fuel Cells and Bioremediation
- Water Treatment and Disinfection
University of Idaho
2017-2024
Hologic (United States)
2023
Montana State University
2007-2018
Oak Ridge National Laboratory
2011-2017
Technical University of Crete
2013
South Dakota School of Mines and Technology
2010
Washington State University
2008
Methylmercury (MeHg) is a bioaccumulative toxic contaminant in many ecosystems, but factors governing its production are poorly understood. Recent work has shown that the anaerobic microbial conversion of mercury (Hg) to MeHg requires Hg-methylation genes hgcAB and these can be used as biomarkers PCR-based estimators Hg-methylator abundance. In an effort determine reliable methods for assessing hgcA abundance diversity linking them concentrations, multiple approaches were compared including...
ABSTRACT Neurotoxic methylmercury (MeHg) is produced by anaerobic Bacteria and Archaea possessing the genes hgcAB , but it unknown how organic substrate electron acceptor availability impacts distribution abundance of these organisms. We evaluated impact amendments on mercury (Hg) methylation rates, microbial community structure, + microbes with sediments. Sediment slurries were amended short-chain fatty acids, alcohols, or a polysaccharide. Minimal increases in MeHg observed following...
ABSTRACT The determination of the success in situ bioremediation strategies is complex. By using controlled laboratory conditions, influence individual variables, such as U(VI), Cr(VI), and electron donors acceptors on community structure, dynamics, metal-reducing potential can be studied. Triplicate anaerobic, continuous-flow reactors were inoculated with Cr(VI)-contaminated groundwater from Hanford, WA, 100-H area, amended lactate, incubated for 95 days to obtain stable, enriched...
Finding new sources of biologically active compounds for anticancer or antimicrobial therapies remains an area research. Azothioformamides (ATFs) with a 1,3 N=N-C=S heterodiene backbone are class that chelate metals (e.g., Cu) forming stable ATF metal coordination complexes. In this study, ligands were prepared pyrrolidine, piperidine,
Because of its high solubility over a wide range pH conditions, zinc is found in many natural and human-impacted systems. Zinc speciation critical assessing toxicity to microorganisms because it varies considerably with dependent on other aqueous constituents. Combined results thermodynamic modeling, statistical analysis, batch culture studies using Arthrobacter sp. JM018 suggest that the toxic species may not be solely limited free ion, but also includes ZnHPO40(aq). Cellular uptake...
Despite over three decades of progress, extraction high molecular weight (HMW) DNA from clay soils or iron oxide cemented has remained challenging. HMW is desirable for next generation sequencing as it yields the most comprehensive coverage. Several procedures were compared samples that exhibit strong nucleic acid adsorption. pH manipulation use alternative ion solutions offered no improvement in recovery. Lysis by liquid N2 grinding concentrated guanidine followed sodium phosphate supported...
Abstract BACKGROUND: Microbial behavior in batch reactors may be different from that continuous flow reactors, which is expected to affect microbial response heavy metal exposure. Four parallel and growth tests were used investigate the single joint toxicity of Zn Cu Artrobacter sp. JM018. RESULTS: The results indicated more toxic than under all conditions. In concentrations showed a stimulatory effect on growth. However system, 125 µmol L −1 exposure produced inhibition. case mixed...
General chemistry laboratories are a core requirement for nearly all STEM (Science, Technology, Engineering, and Mathematics) majors have the greatest breadth in disciplines audience of any course at university. A bioremediation Course-based Undergraduate Research Experience (CURE) first-year undergraduate students was developed to capture engage student interest this diverse group. In multiweek laboratory exercise, joined an NSF-funded research project designed enhance chlorinated aliphatic...
The biogeochemical transformations of mercury are a complex process, with the production methylmercury, potent human neurotoxin, repeatedly demonstrated in sulfate- and Fe(III)-reducing as well methanogenic bacteria. However, little is known regarding morphology, genes, or proteins involved methylmercury generation. Desulfovibrio africanus strain Walvis Bay Hg-methylating δ-proteobacterium sequenced genome has unusual pleomorphic forms. In this study, relationship between pleomorphism Hg...
Redox‐active ligands lead to ambiguity in often clearly defined oxidation states of both the metal center and ligand. The arylazothioformamide (ATF) ligand class represents a redox‐active with three possible redox (neutral, singly reduced, doubly reduced). ATF–metal interactions result strong colorimetric transitions allowing for use ATFs detection and/or separations. While previous reports have discussed dissolution zerovalent metals, resulting coordination complexes proved difficult...
An aqueous mixture of goethite, quartz, and lead chloride (PbCl(2)) was treated with the sulfate-reducing bacterium, Desulfovibrio desulfuricans G20 (D. G20), in a medium specifically designed to assess metal toxicity. In presence 26 muM soluble Pb, together goethite D. grew after lag time 5 days compared 2 Pb-, goethite-, quartz-free treatments. absence however, microM no measurable growth observed. Results showed that first removed Pb from solutions then began resulting black precipitates...
Abstract Redox‐active arylazothioformamide (ATF) ligands, when reacted with Cu I salts, coordinate to form a variety of 1 : dimers and 2 ligand‐metal complexes through N=N−C=S chelation motif. In this study, monosubstituted ( ortho/meta/para ) methoxy regioisomers ATF were synthesized evaluated halide BF 4 salts. UV‐Vis binding association studies revealed model against all species producing para ≫ ortho > meta pattern across the substitution range. To understand why non‐linear was...
The oxidation state of sulfur [S] is a primary control on mobility metals in sediments impacted by legacy mining practices. Coeur d’Alene Lake northern Idaho, USA, has been upstream practices that deposited an estimated 75 Mt metal(loid)- and S-rich into the lake. Future lake conditions are expected to include algal blooms, which may alter S metal remobilization during seasonal euxinic environment. Cores were exposed anoxic + detritus for eight weeks at 4.5 °C through introduction N2...
The release of nanophase metal particles from sulfide mineral decomposition in mining-impacted environments is a growing concern because the potential for transport nanoscale that could increase distribution metals and their environmental impact. An analysis total (unfiltered) dissolved (450-nm filtered) concentrations Coeur d’Alene River indicates leaching forms sediments to within river. between driven by seasonal temperatures, hydraulic gradients, ligand availability. Cd Zn were least...
The straightforward synthesis of redox-active arylazothioformamide (ATF) ligands allows for electronic diversity as to measure the weak-binding interactions transition metal salts in supramolecular coordination complexes. A small library para-substituted ATFs was created with varied components evaluate how electron-donating and electron-withdrawing groups alter binding association constants. Following full characterisation, including single-crystal X-ray diffraction, UV-Vis titration studies...
The heterogeneity and anisotropy of fractured-rock aquifers, such as those in the Columbia River Basalt Province, present challenges for determining groundwater recharge. entrance recharge to fractured-basalt interbedded-sediment aquifer Palouse region north-central Idaho is not well understood because successive basalt flows that act restrictive barriers. It was hypothesized a primary zone exists along basin’s eastern margin at mountain-front interface where eroded sediments form more...