Chlorinated solvents are common groundwater pollutants that often exist as mixtures resulting from the use of multiple solvents and their transformation into chlorinated daughter products. These sites are often co-contaminated with the solvent stabilizer 1,4-dioxane (1,4-D), which is not treated by traditional chlorinated solvent remediation techniques. Both 1,4-D and chlorinated...
Chlorinated aliphatic hydrocarbons (CAHs) like trichloroethene (TCE) were mostly used to replace drying cleaning fluids which contained hydrocarbons like benzene, and were highly flammable. Through improper disposal, storage, and spills, TCE and its downstream products, like cis-dichloroethene (cDCE) and vinyl chloride (VC), leached into groundwater and threaten human and environmental...
Methods were developed for the co-encapsulation of slow release compounds (SRC) with viable microbial cells in alginate and gellan gum hydrogel beads, for the in-situ aerobic cometabolic treatment of groundwater contaminated with mixtures of 1,4-dioxane and chlorinated aliphatic hydrocarbons, which will be referred to as contaminants of concern (CoC). The...
The cometabolic ability of Burkholderia vietnamiensis G4 grown on aromatic substrates was first assessed by resting suspended cells, and subsequently for cells encapsulated with and without slow release compounds (SRCs). In Chapter 3, benzyl alcohol was assessed as a food-grade growth substrate for promoting cometabolism of trichloroethene (TCE), via the...
As access to potable water grows scarce, there is an increasing reliance on alternative drinking water sources, namely groundwater (WHO, 2018). Chlorinated solvents, such as 1,1,1-trichloroethane (TCA) and 1,2-cis-Dichloroethene (cisDCE) are some of the most ubiquitous groundwater contaminants spread throughout the US. 1,4-dioxane (1,4D) was used primarily in the late...
This thesis explores the factors limiting the alkene substrate range of the vinyl chloride (VC)-utilizing bacteria, and describes a method for measuring VC transformation in situ. Vinyl fluoride (VF) was evaluated as a surrogate for monitoring aerobic VC-transformation utilizing three isolates, Mycobacterium EE13a, Mycobacterium JS60 and Nocardioides JS614. JS614 grew...
1,4-dioxane and chlorinated aliphatic hydrocarbons (CAHs) such as trichloroethylene (TCE) and 1,1-dichloroethene (1,1-DCE) are hazardous compounds commonly found in soil and groundwater. Bioremediation through aerobic cometabolism is a potential option for the remediation of these contaminated sites. The purpose of this study was to examine the use of different primary...
Mixtures of 1,4-dioxane (1,4-D) and chlorinated aliphatic hydrocarbons (CAHs) are common and hazardous groundwater contaminants that can be challenging to address with traditional remediation strategies. Bioremediation through aerobic cometabolism has the potential to be an effective in-situ treatment strategy for these contaminants. Rhodococcus rhodochrous strain ATCC 21198 is capable of...
The goal of this research was to mathematically simulate the ability of bioaugmented microorganisms to aerobically cometabolize a mixture of chlorinated aliphatic hydrocarbon (CAH) compounds during in-situ treatment. Parameter values measured from laboratory experiments were applied to the transport model with biotransformation processes included. In laboratory microcosm studies, a butane-grown,...
Continuous-flow and batch experiments were conducted with a column reactor
system containing Hanford aquifer material in order to evaluate the potential of in-situ
bioremediation of carbon tetrachloride (CT) at Hanford. The effectiveness of benzoate
and acetate as primary substrates was considered. Nitrate and sulfate were potential
electron acceptors. Transport experiments...