Removal of chemical species by electrically charged bicomponent fibers
AdvisorLarson, Dennis L.
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PublisherThe University of Arizona.
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.
AbstractA new water deionization method was conceived and investigated. Bench scale reactors were designed and tested. Numerical analysis of ion movement in water in the presence of electrical, hydraulic, and chemical gradients was conducted. The new water treatment technology uses bicomponent fibers (BCF). Ions in water are concentrated near charged bicomponent fibers. Bicomponent fibers are composed of two materials. The outer annulus is made of nylon and has an inside diameter of 10 mum and outer diameter of 50 mum. The inner annulus is composed of carbon powder and has an outer diameter of 10 mum. For the bench scale reactors, approximately one kilometer length of fibers was wrapped around a series of plastic panels and placed in a plexiglass container containing sodium nitrate solution. The ends of the fibers were covered with electrically conductive epoxy and connected to a DC power supply. In experiments which lasted up to 96 h., the solution showed up to 50 percent decrease in nitrate concentration after the power supply was applied. Preliminary studies indicated that distance between panels, polarity of panels and voltage magnitude influenced observed concentration. Two one dimensional analytical solutions and finite element solutions for two dimensions were derived for no flow condition between parallel plates. For the first finite element model, the continuity, Navier-Stokes, and species equations were solved for solute concentration with rectangular coordinates. For the second model, Poisson-Boltzmann equations were included in a finite element scheme. The models were applied to irregular-shaped bodies and the finite element solutions were compared with analytical solutions. The solutions for Poisson-Boltzmann equations were obtained for both linearized and non-linear forms. Boundary conditions included no chemical reactions and no transport across boundaries. The formulations did not solve for concentration in bicomponent fiber reactors because insufficient data and knowledge of the bicomponent fiber process is available. However, future numerical models of the bicomponent fiber treatment process may be based on solutions derived in this research.
Degree ProgramGraduate College
Agricultural and Biosystems Engineering