The effect of electrokinetic phenomena on the performance of ceramic membranes is studied. The results of experiments that evaluate the effects of the ionic strength, pH and the composition of the feed water on the performance of ceramic microfiltration membranes are reported. Theoretical calculations that estimate the electroviscous effect on membrane performance are presented and compared to experimental observations. Experiments were conducted on the membranes with cross-flow filtration mode and dead-end filtration mode. The electrokinetic properties of the membrane and pore surfaces were evaluated. The ionic strength and pH of the feed water are shown to affect membrane permeation behavior. This effect was shown to vary with average pore size, structure and composition of the membrane. Electroviscous considerations were shown to account partially to the observed effects of the feed water chemistry on the permeate flux. The composition of the electrolyte solution and the mobility of the ions in solution were also shown to influence membrane permeation rates. Theoretical considerations indicate that the effect of electrokinetic phenomena were shown to be significant for membranes with high pore surface potential ($\geq-$100 mV) and at intermediate electrokinetic radii, $\kappa$a $\sim$ 2. This condition corresponds to a membrane with a pore radius, a of 0.1 $\mu$m and ionic strength of $2.5\times10\sp{-5}$ M resulting in a Debye parameter, $\kappa$ around $2\times10\sp7 {\rm m}\sp{-1}.$
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/16965 |
| Date | January 1996 |
| Creators | Nazzal, Faten Fayez |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | application/pdf |
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