AWWA MTC64616

A major concern in the application of microfiltration membranes is the fouling ofthe membrane (that is, the irreversible blocking of pores by colloidal/particulate matterand by the macromolecules of natural organic matter). Research has demonstrated thatpore size characteristics (maximum, minimum, and mean values of the major axis, minoraxis, and aspect ratio) impact membrane performance (flux, rejection, and permeateparticle size distribution). Recent investigations have examined the effect ofuni-axial stretching of membranes on the performance properties and performance ofmicrofiltration polymer membranes. Membranes made via phase inversion and track-etch(TE) methods have been investigated. These investigations included experimentalstudies that show stretching increased permeability beyond that caused by the reductionin thickness. The results also showed improved rejection capabilities for somemembranes.The research included modeling the changes in the pore size characteristicscaused by uni-axial stretching. The modeling of the deformation process, which isperformed using finite element analysis, is discussed in this paper. Finiteelement analysis is used as there is not a closed-form solution of elliptical void growththat adequately takes into account interactions between pores. Specifically, thispaper emphasizes the modeling of pore size and shape changes resulting fromthe stretching of TE membranes. TE membranes are used because of the simplisticgeometries. While often described as circular straight throughpores of a uniform size, TE membranes often have angled pores, creating elliptical poreopenings. Models of the changes in track-etch membranes have been completed for asimplified 2-D system, where pores are circular and pass straight through the membrane,for a 2-D system with elliptical pores, and for a 3-D system that includes angledcylindrical pores. Includes figures.

Product Details

Edition:

Vol. - No.

Published:

03/01/2007

Number of Pages:

6

File Size:

1 file , 670 KB