Date of Award

Spring 2017

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Mathematical Sciences - (Ph.D.)

Department

Mathematical Sciences

First Advisor

Linda Jane Cummings

Second Advisor

Lou Kondic

Third Advisor

Michael Siegel

Fourth Advisor

Ian Griffiths

Fifth Advisor

Emilie Marie Dressaire

Sixth Advisor

Anil Kumar

Abstract

The purpose of this thesis is to formulate and investigate new mathematical models for membrane filtration. The work presented is divided into six chapters. In the first chapter the problem is introduced and motivated. In the second chapter, a new mathematical model for flow and fouling in a pleated membrane filter is presented. Pleated membrane filters are widely used in many applications, and offer significantly better surface area to volume ratios than equal area unpleated membrane filters. However, their filtration characteristics are markedly inferior to those of equivalent unpleated membrane filters in dead-end filtration. While several hypotheses have been advanced for this, one possibility is that the flow field induced by the pleating leads to spatially nonuniform fouling of the filter, which in turn degrades performance. This hypothesis is investigated by developing a simplified model for the flow and fouling within a pleated membrane filter. The model accounts for the pleated membrane geometry (which affects the flow), for porous support layers surrounding the membrane, and for two membrane fouling mechanisms: (i) adsorption of very small particles within membrane pores; and (ii) blocking of entire pores by large particles. Asymptotic techniques are used based on the small pleat aspect ratio to solve the model, and solutions are compared to those for the closest-equivalent unpleated filter.

Included in

Mathematics Commons

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