Development of an Electrochemical Reactor for the Aqueous Phase Destruction of Chlorinated Hydrocarbons

Persistent Link:
http://hdl.handle.net/10150/195095
Title:
Development of an Electrochemical Reactor for the Aqueous Phase Destruction of Chlorinated Hydrocarbons
Author:
Wang, Lei
Issue Date:
2008
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:
A cylindrical electrochemical reactor with a 3 in diameter copper or nickel metal foam cathode and a concentric carbon cloth anode was used to destroy aqueous phase carbon tetrachloride (CT). The results show that a high CT conversion can be achieved in regions of the cathode near the anode, but a low CT conversion is obtained in the region around the center of the cathode. This CT conversion distribution in the radial current-conducting direction suggests that a portion of the cathode worked inefficiently even though the overall CT conversion is still adequate. Further research by changing the solution pH and conductivity suggests that the radial conversion distribution is due to radial variations in cathode surface availability. The inherent difficulties that these results imply with regards to reactor scale up suggested a new approach to the design. An annular reactor, consisting of a thin (3.2 mm) nickel foam cathode wrapped around an inert Plexiglas core and separated for an external concentric anode by a semi-permeable membrane was adopted. Under compatible operating conditions, the annular reactor showed a high overall effluent CT conversion. However, experiments at low pH (2.25) yielded higher conversions than under neutral pH conditions. This result suggests that CT conversion is favored by a relatively high proton concentration. This reactor can be simulated by a one dimensional model. The annular reactor was used to destroy PCE and TCE successfully, which suggests that this technique can be employed to treat groundwater contaminated with complex mixtures of chlorinated hydrocarbons.A multi-layer reactor based on the principle of the annular reactor was developed as an option for the scale up of the system. This reactor exhibited high and uniform radial CT conversion.
Type:
text; Electronic Dissertation
Keywords:
Aqueous; Dechlorination; Electrochemical; Electrode; Groundwater remediation; PCE TCE CT
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemical Engineering; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Sáez, A. Eduardo; Arnold, Robert G.
Committee Chair:
Sáez, A. Eduardo

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleDevelopment of an Electrochemical Reactor for the Aqueous Phase Destruction of Chlorinated Hydrocarbonsen_US
dc.creatorWang, Leien_US
dc.contributor.authorWang, Leien_US
dc.date.issued2008en_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.abstractA cylindrical electrochemical reactor with a 3 in diameter copper or nickel metal foam cathode and a concentric carbon cloth anode was used to destroy aqueous phase carbon tetrachloride (CT). The results show that a high CT conversion can be achieved in regions of the cathode near the anode, but a low CT conversion is obtained in the region around the center of the cathode. This CT conversion distribution in the radial current-conducting direction suggests that a portion of the cathode worked inefficiently even though the overall CT conversion is still adequate. Further research by changing the solution pH and conductivity suggests that the radial conversion distribution is due to radial variations in cathode surface availability. The inherent difficulties that these results imply with regards to reactor scale up suggested a new approach to the design. An annular reactor, consisting of a thin (3.2 mm) nickel foam cathode wrapped around an inert Plexiglas core and separated for an external concentric anode by a semi-permeable membrane was adopted. Under compatible operating conditions, the annular reactor showed a high overall effluent CT conversion. However, experiments at low pH (2.25) yielded higher conversions than under neutral pH conditions. This result suggests that CT conversion is favored by a relatively high proton concentration. This reactor can be simulated by a one dimensional model. The annular reactor was used to destroy PCE and TCE successfully, which suggests that this technique can be employed to treat groundwater contaminated with complex mixtures of chlorinated hydrocarbons.A multi-layer reactor based on the principle of the annular reactor was developed as an option for the scale up of the system. This reactor exhibited high and uniform radial CT conversion.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectAqueousen_US
dc.subjectDechlorinationen_US
dc.subjectElectrochemicalen_US
dc.subjectElectrodeen_US
dc.subjectGroundwater remediationen_US
dc.subjectPCE TCE CTen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemical Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSáez, A. Eduardoen_US
dc.contributor.advisorArnold, Robert G.en_US
dc.contributor.chairSáez, A. Eduardoen_US
dc.contributor.committeememberSáez, A. Eduardoen_US
dc.contributor.committeememberArnold, Robert G.en_US
dc.contributor.committeememberBetterton, Eric A.en_US
dc.contributor.committeememberBlowers, Paulen_US
dc.identifier.proquest10095en_US
dc.identifier.oclc659750583en_US
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