At Site-300, Lawrence Livermore National Laboratory (LLNL), CA,
trichloroethene (TCE) is present along with tetraalkoxysilanes such as tetrabutoxysilane
(TBOS) and tetrakis(2-ethylbutoxy) silane (TKEBS), as subsurface contaminants.
Intrinsic transformation of TCE to cis-dichloroethene (c-DCE) was observed in the
groundwater at locations co-contaminated with TBOS or TKEBS. Attenuation of TBOS
and TKEBS...
This study investigated the use of radon-222 as an in situ partitioning tracer for quantifying nonaqueous phase liquid (NAPL) saturations in the subsurface. Laboratory physical aquifer models (PAMs), field experiments, and numerical simulations were used to investigate radon partitioning in static (no-flow) experiments and in single-well, 'push-pull' tests conducted in...
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...
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Table 23. Two-sample t-Tests assuming unequal variances between all combinations of treatments
This study investigated complete reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs) over a broad range of concentrations. Tetrabutoxysilane (TBOS), as a slow-release anaerobic substrate, was studied for enhanced reductive dechlorination of tetrachioroethylene (PCE) present as a dense non-aqueous liquid (DNAPL). Four different site-mixed cultures were used in the study: Site-300...
The aerobic transformation of TCE and cis-DCE by a tetrabutoxysilane-grown microorganism (Vancheeswaran et al., 1999) led to the investigation of novel substrates, including benzyl alcohol, for promoting cometabolism. The culture grew on carboxylic compounds and alcohols, but did not grow on formate, methanol, methane, propane, butane, ethylene, benzene, toluene, or...
CisCis-Dichloroethylene (ciscis-DCE), 1,1,1-Trichloroethane (1,1,1-TCA), and 1,4-Dioxane (1,4-D) are chlorinated solvents used as solvents and degreasers in industrial cleaning agents that have become common groundwater contaminants. To develop an effective treatment method for these compounds, polyvinyl alcohol (PVA) and sodium alginate (SA) hydrogel beads were co-entrappcapsulated with Rhodococcus rhodochrous Strain ATCC...
1,4-Dioxane (dioxane) and cis-dichloroethylene (cDCE) are compounds commonly found in industrial cleaning and degreasing agents that are frequently present as groundwater contaminants. In an effort to develop a more effective treatment method for these compounds, hydrogel beads were fabricated with either gellan gum or a combination of polyvinyl alcohol (PVA)...
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...