Engineering >> Civil & Environmental EngineeringA Mathematical Model of Pore Diffusion in an Ion Exchange Materialby Odelmo Joseph
Submitted : Spring 2015 Ion exchange is a process used to remove dissolved ionic constituents that can cause aesthetic and health issues. The ion exchange process for water treatment is considered to be a nonconventional process because it is not widely used in large-scale plants (Crittenden et al., 2012). Water containing these ions are not only hazardous to our bodies but to certain surfaces and machines they come in contact with. For example some car washes only used purified water to wash cars because the hard water damages the paint and other components of the vehicle. Ions are positively or negatively charged particles. A bulk liquid containing these ions undergoes processes where it is sometimes heated and filtered through special resins made up of different materials containing an overall net charge of its own that attracts the harmful ions. After these processes are completed the resulting water that exits a reactor with the ion exchange material should be purified, with lower concentrations of ionic species that have negative health and environmental impacts. The effluent water can be used for drinking water, and in some manufacturing operations without the issue of accumulation of materials within pipes over time. The application of natural ion exchange materials for water treatment may have been used as far back as biblical times when Moses sweetened the waters of Mariah (Exodus 15:23–25). In approximately 320 BC, Aristotle used 20 earthen containers containing a material with ion exchange properties to produce freshwater from seawater (Wachinski and Etzel, 1997).
Currently more and more research is being conducted into finding new and efficient ways to remove these ions from water. Mathematical modeling of an ion exchange process is an integral tools for predicting the fate and transport of ions in a reactor with ion exchange materials. These mathematical models can facilitate enhanced design and optimization of ion exchange systems. In this project a pore diffusion was developed to mechanistically describe the ion exchange phenomena.
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