Rapid reductive dechlorination of environmentally hazardous aromatic compounds and pesticides

Persistent Link:
http://hdl.handle.net/10150/282335
Title:
Rapid reductive dechlorination of environmentally hazardous aromatic compounds and pesticides
Author:
Grittini, Carina
Issue Date:
1997
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Organochlorine compounds, such as polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), p,p'-DDE and Toxaphene, have been widely used in industry and agriculture for more than fifty years. Although they have served their purpose very effectively and at low cost, many of these compounds have been banned in the United States due to their persistence in the environment and their threat to human health. Their natural resistance to degradation has made organochlorine compounds the target of many studies that have been designed to convert them into less toxic compounds. At present there is not a single, simple method than can completely dechlorinate PCBs, PCP, p,p'-DDE and Toxaphene. The work presented here reports the use of a novel bimetallic system, palladized iron (Pd/Fe), to effect the complete dechlorination of these compounds, at ambient temperature and pressure, in a matter of minutes. The dechlorination reaction occurs on the surface of the palladized iron, with removal of all the chlorine atoms from the chlorinated compound and yields the completely dechlorinated molecule and chloride ions as reaction products. The chlorinated compound is reductively dechlorinated while the iron particles are oxidized to Fe²⁺ Water is also reduced in the presence of iron, generating hydrogen, which is collected in the palladium lattice. The palladium is therefore necessary to store hydrogen gas; the "Pd·H₂" acts as a powerful reducing agent and is primarily responsible for the rapid and complete dechlorination of the organochlorine compounds. The Pd/Fe bimetallic system is potentially useful for the large scale remediation of groundwater or soil contaminated with organochlorine compounds. Palladized iron is relatively inexpensive and easy to prepare, and it rapidly and completely dechlorinates organochlorine compounds. For these reasons, the Pd/Fe system should be investigated further for applications in the field.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Analytical.; Environmental Sciences.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Fernando, Quintus

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleRapid reductive dechlorination of environmentally hazardous aromatic compounds and pesticidesen_US
dc.creatorGrittini, Carinaen_US
dc.contributor.authorGrittini, Carinaen_US
dc.date.issued1997en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractOrganochlorine compounds, such as polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), p,p'-DDE and Toxaphene, have been widely used in industry and agriculture for more than fifty years. Although they have served their purpose very effectively and at low cost, many of these compounds have been banned in the United States due to their persistence in the environment and their threat to human health. Their natural resistance to degradation has made organochlorine compounds the target of many studies that have been designed to convert them into less toxic compounds. At present there is not a single, simple method than can completely dechlorinate PCBs, PCP, p,p'-DDE and Toxaphene. The work presented here reports the use of a novel bimetallic system, palladized iron (Pd/Fe), to effect the complete dechlorination of these compounds, at ambient temperature and pressure, in a matter of minutes. The dechlorination reaction occurs on the surface of the palladized iron, with removal of all the chlorine atoms from the chlorinated compound and yields the completely dechlorinated molecule and chloride ions as reaction products. The chlorinated compound is reductively dechlorinated while the iron particles are oxidized to Fe²⁺ Water is also reduced in the presence of iron, generating hydrogen, which is collected in the palladium lattice. The palladium is therefore necessary to store hydrogen gas; the "Pd·H₂" acts as a powerful reducing agent and is primarily responsible for the rapid and complete dechlorination of the organochlorine compounds. The Pd/Fe bimetallic system is potentially useful for the large scale remediation of groundwater or soil contaminated with organochlorine compounds. Palladized iron is relatively inexpensive and easy to prepare, and it rapidly and completely dechlorinates organochlorine compounds. For these reasons, the Pd/Fe system should be investigated further for applications in the field.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Analytical.en_US
dc.subjectEnvironmental Sciences.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorFernando, Quintusen_US
dc.identifier.proquest9729511en_US
dc.identifier.bibrecord.b34819198en_US
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