Learn More
Methods are needed to obtain in situ information on the transformation rates of trichloroethene (TCE), the most commonly detected organic groundwater contaminant. The objective of this research was to investigate the potential for determining TCE transformation rates in groundwater by measuring the transformation rate of its fluorinated surrogate,(More)
Previous environmental applications of partitioning tracer tests to detect and quantify nonaqueous phase liquid (NAPL) contamination in the subsurface have been limited to well-to-well tests. However, theory and numerical modeling suggests that single-well injection-extraction ("push-pull") partitioning tracer tests can also potentially detect and quantify(More)
In situ methods are needed to evaluate the effectiveness of chemical amendments at enhancing reductive dechlorination rates in groundwater that is contaminated with the priority pollutant, trichloroethene (TCE). In this communication, a method that utilizes single-well, "push-pull" tests to quantify the effects of chemical amendments on in situ reductive(More)
Identifying metabolites associated with anaerobic hydrocarbon biodegradation is a reliable way to garner evidence for the intrinsic bioremediation of problem contaminants. While such metabolites have been detected at numerous sites, the in situ rates of anaerobic hydrocarbon decay remain largely unknown. Yet, realistic rate information is critical for(More)
Nitrite is a substrate but also an inhibitor of anaerobic ammonium oxidation (anammox).There is currently no consensus on whether ionized nitrite (INi) or free nitrous acid (FNA) is the actual inhibitor of the process. The inhibition by INi and FNA on the anammox process has been analysed using a wide range of INi and FNA concentrations and by altering the(More)
At many trichloroethene (TCE)-contaminated field sites, microbial transformation of TCE results in the accumulation of vinyl chloride (VC), a known carcinogen and neurotoxin. Quantitative tools are needed to determine the in situ rates of VC transformation to ethene in contaminated groundwater. For this study, E-/Z-chlorofluoroethene (E-/Z-CFE) was(More)
Lego Mindstorms robots kits are popular hands-on robotics tools for math, science and engineering education. The recently developed NXT system is much more powerful than the previous RCX system, and has great potential for scholarly research. In this paper, we investigated and tested the capabilities and limitations of NXT system for its application to(More)
BACKGROUND This commentary evolved from a workshop sponsored by the National Institute of Environmental Health Sciences titled "Superfund Contaminants: The Next Generation" held in Tucson, Arizona, in August 2009. All the authors were workshop participants. OBJECTIVES Our aim was to initiate a dynamic, adaptable process for identifying contaminants of(More)
Trichlorofluoroethene (TCFE) was used as a reactive tracer to determine the in situ rate of reductive dechlorination in treatment zones impacted by three large-diameter permeable columns (LDPCs) that were installed at a trichloroethene (TCE)–contaminated site. The LDPCs were part of a pilot study to evaluate the effectiveness of hydrogen, lactate, and(More)