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Full-Text Articles in Engineering
Evaluation Of Anaerobic Biodegradation Of High Concentrations Of Halogenated Methanes, Priya Rachel Jacob
Evaluation Of Anaerobic Biodegradation Of High Concentrations Of Halogenated Methanes, Priya Rachel Jacob
All Theses
Removal of the chlorinated methanes, carbon tetrachloride (CT), chloroform (CF) and dichloromethane (DCM), and the halogenated methane, trichlorofluoromethane (commonly known as CFC-11 or Freon-11) from contaminated soil and groundwater remains challenging. Releases to the environment resulted from historically poor disposal practices, as well as spills and leaks from underground storage tanks. Among these three compounds, CF is considered the benchmark for evaluating the feasibility of bioremediation, due to its typically high level of toxicity towards most anaerobic prokaryotes. However, inhibitory effects of low concentrations of CFC-11 on anaerobes have been reported as well. Bioremediation is an attractive option for clean-up, …
Evaluation Of The Biodegradability And Toxicity Of Pca And Mpca, Juan Rueda
Evaluation Of The Biodegradability And Toxicity Of Pca And Mpca, Juan Rueda
Electronic Theses and Dissertations
The main types of hypergolic propellants used at Kennedy Space Center (KSC) are hydrazine (HZ) and monomethylhydrazine (MMH). HZ and MMH are classified as hazardous materials and they are also known to be potentially carcinogenic to humans; therefore, handling these substances and their waste is strictly regulated. The wastes streams from HZ and MMH have been estimated to be the main hazardous wastes streams at KSC. Currently at KSC these wastes are first neutralized using citric acid and then they are transported on public roads for incineration as hazardous materials. A new method using alpha ketoglutaric acid (AKGA) was proposed …
Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo
Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo
LSU Doctoral Dissertations
Sustainable treatment of chlorinated ethanes and ethenes contaminated groundwater using vertical flow engineered wetland systems were investigated in microcosm and column studies. Experiments on environmental and biogeochemical factors that affect system performance were conducted, and a numerical model involving advection, sorption, and sequential biodegradation was developed to describe the fate and transport of the contaminants of concern in the treatment wetland bed. 1,1-dichloroethane (1,1-DCA) and cis-1,2-dichloroethene (cis-1,2-DCE) were used as the chemicals of interest. The presence of cis-1,2-DCE inhibited dechlorination of 1,1-DCA but cis-1,2-DCE dechlorination was not affected by the presence of 1,1-DCA. Simulation runs showed that the treatment bed …
Degradation And Inhibition Of Chlorinated Ethanes And Ethenes In A Two Bed, Sequential Bioremediation System, Alex Boudreau
Degradation And Inhibition Of Chlorinated Ethanes And Ethenes In A Two Bed, Sequential Bioremediation System, Alex Boudreau
LSU Master's Theses
A continuous-flow system composed of two anaerobic bioreactor (ABR) columns (based on engineered wetland systems) connected in series was tested to observe the ability of such a system to treat multiple volatile organic compounds (VOCs) possessing suspected inhibitory effects on the dechlorination of other compounds with cis-1,2-dichloroethylene (cDCE) and 1,1-dichloroethane (1,1-DCA) as the main test chemicals. Following the establishment of cDCE and 1,1-DCA dechlorinating ability at baseline conditions, system perturbations of breakthrough and starvation were conducted to measure the response and recovery of the system dechlorination. In all column experiments, it was observed cDCE dechlorination inhibited the dechlorination of 1,1-DCA …