No description available.

Graduation date: 1999

Graduation date: 1995

Chlorinated phenols are toxic compounds and often released into natural environments from improper disposal or non-point sources. One important factor in assessing the environmental fate and transport is the rates of microbial degradation in soils and natural waters. In this study, eight chlorophenols (4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 3,4-dichlorophenol (3,4-DCP), 3,5-dichlorophenol (3,5- DCP), 2,3,5-trichlorophenol (2,3,5-TCP), 2,4,5-trichlorophenol (2,4,5-TCP), 3,4,5- trichlorophenol (3,4,5-TCP), and 2,4,6-trichlorophenol (2,4,6-TCP)) were chosen as the model compounds because they represent the major degradation products for the anaerobic metabolic products of pentachlorophenol (PCP). Aerobic degradation rates of all eight compounds were determined under controlled laboratory conditions. A mixed bacterial culture was seeded from a municipal wastewater treatment plant and were grown with acetate as a primary substrate and the eight chlorophenols as secondary substrates. Rates of degradation were measured in a batch reactor with an initial concentration of acetate of 1000 mg/l and of the individual chlorophenol of 0.1 mg/l. Rate of acetate and chlorophenols were modelled using a Monod model. The maximum rate of acetate utilization was zero-order in relation to acetate concentration and first-order with respect to organism concentration. The rate of chlorophenol degradation were zero-order in relation to the chlorophenol concentration. The relative rates of degradation were in general as follows: monochlorophenol > dichlorophenols > trichlorophenols. / Graduation date: 1992

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 115-125). Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 223-234).

No description available.

No description available.

Disposal of chlorinated hydrocarbons is a major environmental concern due to the lack of a satisfactory means of safe remediation at all contaminated locations. Current technologies rely primarily on incineration, a process that can lead to dangerous byproducts such as dioxin. If the chlorine substituent can be removed prior to incineration, or other disposal method, the subsequent steps of disposal pose less of an environmentally risk. The catalyst developed in this study is designed to promote the dechlorination reaction. A methodology for the production of a palladium based metal support catalyst is presented. This technique allows the palladium catalyst to be deposited on a copper metal surface. The catalyst is active in the dechlorination of p-chlorophenol, which is used as model molecule representing a range of chlorinated phenolic compounds. Hydrogen is used in the concert with catalyst to affect the dechlorination. Chemical process rates of 0.3-1.0 cm³/g*s are observed. / Graduation date: 2001

Graduation date: 2002