Browsing by Author "Rogers, Robert D."

Now showing 1 - 5 of 5

Bioprocessing of environmentally significant gases and vapors with gas-phase bioreactors
(1993-02) Apel, William A.; Dugan, Patrick R.; Wiebe, Michelle R.; Johnson, Earl G.; Wolfram, James H.; Rogers, Robert D.
Fixed thin film, gas/vapor phase bioreactors were assessed relative to their potential for the bioprocessing of methane, trichloroethylene (TCE), and p-xylene. Methanotrophic bacteria were used to process the methane and TCE while a xylene resistant strain of Pseudomonas putida was used to process the p-xylene. Comparisons between the gas phase bioreactors and conventional shaken cultures and sparged liquid bioreactors showed that the gas phase bioreactors offer advantages over the other two systems for the degradation of methane in air. Rates of methane removal with the gas phase bioreactors were 2.1 and 1.6 fold greater than those exhibited by the shaken cultures and sparged liquid bioreactors, respectively. The gas phase bioreactors were shown to have application for the removal of TCE vapors from air with a removal rate of approximately 9 μg TCE d-1 bioreactor-1. Xylene vapors were also scrubbed from air using gas phase bioreactors. At a feed rate of 140 μg of xylene min-1, approximately 46% of the xylene was mineralized to carbon dioxide in a single pass through a bench scale gas phase bioreactor.
Evidence of microbially influenced corrosion of boral used in spent fuel canisters
(1991) Wolfram, James H.; Miller, R. L.; Rogers, Robert D.
Microbial processing of volatile organics in industrial waste streams
(1992) Wolfram, James H.; Rogers, Robert D.; Higdem, D. M.
A strain of Pseudomonas putida has been isolated which tolerates and metabolizes toluene and p‐xylene. In our laboratory, this isolate has undergone selection and adaptation and presently is able to grow under a layer of 100% p‐xylene. From batch studies the initial rates of degradation are 1–3 mg/min/L. This strain of P. putida also tolerates the presence of a nonionic surfactant while still maintaining its metabolic activity. Preliminary testing using this isolate under chemostat conditions indicates that the potential for developing a bioprocess to treat these waste solvents may be possible.
Microbially influenced degradation of cement-solidified low-level radioactive waste forms
(1994) Rogers, Robert D.; Hamilton, W. A.; Veeh, Richard Harold; McConnell, J. W.
Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. This paper contains information on three groups of microorganisms that are associated with the degradation of cement materials : sulfur-oxidizing bacteria (Thiobacillus), nitrifying bacteria (Nitrosomonas and Nitrobacter), and heterotrophic bacteria, which produce organic acids. Preliminary work using laboratory- and vendor-manufactured, simulated waste forms exposed to thiobacilli has shown that microbiologically influenced degradation has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium was leached from the treated waste forms. Also, the surface pH of the treated specimens was decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 30 to 60 days of exposure.
Use of soil column test apparatus for evaluation of in situ bioremediation potential
(1990) Jones, Warren L.; Sturman, Paul J.; Ellison, C.; Camper, Anne K.; Inskeep, William P.; Rogers, Robert D.; Cunningham, Alfred B.