Modeling Electrochemical Water Treatment Processes

Several electrochemical processes are modeled at process levels and atomic scales. Processes are presented for acid generation and ion exchange media regeneration, along with corresponding process models. Transport and reaction processes in individual ion exchange beads are also modeled. Acids of...

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Main Author: Hubler, David K.
Other Authors: Baygents, James C.
Language:en
Published: The University of Arizona. 2012
Subjects:
Online Access:http://hdl.handle.net/10150/265367
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spelling ndltd-arizona.edu-oai-arizona.openrepository.com-10150-2653672015-10-23T04:59:01Z Modeling Electrochemical Water Treatment Processes Hubler, David K. Baygents, James C. Farrell, James Arnold, Robert Lamoureux, Christopher Baygents, James C. density functional theory electrochemical processes perchlorate water treatment Chemical Engineering boron-doped diamond copper Several electrochemical processes are modeled at process levels and atomic scales. Processes are presented for acid generation and ion exchange media regeneration, along with corresponding process models. Transport and reaction processes in individual ion exchange beads are also modeled. Acids of mild strength (pH = ~1-2) are generated from electrolyte solutions and their strength is effectively modeled as a function of time. The regeneration of ion exchange media is also modeled, to close agreement with measurements, and the process model is reconciled with a model for solute flux from an individual ion exchange bead. Together, the models show that the "gentle" regeneration process is controlled by the plating rate. Processes interior to the particle are controlled by diffusion, but all processes are faster than the characteristic time for plating. In a separate process, an electrochemical method is used to produce hypochlorite for disinfection. The process generates perchlorate as a toxic byproduct. Density function theory is used to construct an atomic-scale model of the mechanism for producing perchlorate, as well as the aging of the boron-doped diamond anode used in the process. The mechanism shows that the boron-doped diamond surface plays an important role in chemisorbing and stabilizing radicals of oxychlorine anions, allowing the radicals to live long enough to react and form higher ions like perchlorate. Wear mechanisms that occur on the anode are shown to oxidize and etch the surface, changing its chemical functionality over time. As the surface ages, the overpotential for water oxidation is decreased, decreasing the efficiency of the electrode. 2012 text Electronic Dissertation http://hdl.handle.net/10150/265367 en 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. The University of Arizona.
collection NDLTD
language en
sources NDLTD
topic density functional theory
electrochemical processes
perchlorate
water treatment
Chemical Engineering
boron-doped diamond
copper
spellingShingle density functional theory
electrochemical processes
perchlorate
water treatment
Chemical Engineering
boron-doped diamond
copper
Hubler, David K.
Modeling Electrochemical Water Treatment Processes
description Several electrochemical processes are modeled at process levels and atomic scales. Processes are presented for acid generation and ion exchange media regeneration, along with corresponding process models. Transport and reaction processes in individual ion exchange beads are also modeled. Acids of mild strength (pH = ~1-2) are generated from electrolyte solutions and their strength is effectively modeled as a function of time. The regeneration of ion exchange media is also modeled, to close agreement with measurements, and the process model is reconciled with a model for solute flux from an individual ion exchange bead. Together, the models show that the "gentle" regeneration process is controlled by the plating rate. Processes interior to the particle are controlled by diffusion, but all processes are faster than the characteristic time for plating. In a separate process, an electrochemical method is used to produce hypochlorite for disinfection. The process generates perchlorate as a toxic byproduct. Density function theory is used to construct an atomic-scale model of the mechanism for producing perchlorate, as well as the aging of the boron-doped diamond anode used in the process. The mechanism shows that the boron-doped diamond surface plays an important role in chemisorbing and stabilizing radicals of oxychlorine anions, allowing the radicals to live long enough to react and form higher ions like perchlorate. Wear mechanisms that occur on the anode are shown to oxidize and etch the surface, changing its chemical functionality over time. As the surface ages, the overpotential for water oxidation is decreased, decreasing the efficiency of the electrode.
author2 Baygents, James C.
author_facet Baygents, James C.
Hubler, David K.
author Hubler, David K.
author_sort Hubler, David K.
title Modeling Electrochemical Water Treatment Processes
title_short Modeling Electrochemical Water Treatment Processes
title_full Modeling Electrochemical Water Treatment Processes
title_fullStr Modeling Electrochemical Water Treatment Processes
title_full_unstemmed Modeling Electrochemical Water Treatment Processes
title_sort modeling electrochemical water treatment processes
publisher The University of Arizona.
publishDate 2012
url http://hdl.handle.net/10150/265367
work_keys_str_mv AT hublerdavidk modelingelectrochemicalwatertreatmentprocesses
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