Permeability and ion filtration characteristics of surface-modified porous aluminum alloy

Abstract

For the water purification filters, the specific surface area should be enlarged to improve the filtration efficiency because the pore surface acts as an adsorption site with impurities. In this study, porous Al-4wt.% Cu alloy was manufactured by P/M process and surface modification. The granulated powder was fabricated by low energy ball mill and was compacted under the pressure of 20 MPa for macropore network. After sintering, the sintered body was surfacemodified in dilute alkali solution for microporous surface. Permeability and filtration characteristics evaluated by specially manufactured device using pure water and artificial waste water with PO4 2- and NH4 +. The specimen surface-modified by lower alkali solution concentration had better phosphate ion removal characteristics in spite of relatively lower permeability. It was considered that the enlarged surface area would cause lower permeability because of frictional effect and ion exchange between phosphate and hydroxide groups might lead better phosphate ion removal characteristics.