Organic-inorganic membranes for filtration of corn distillery

Organic-inorganic membranes were obtained by modification of polymer microfiltration membrane with inorganic ion-exchangers, which form secondary porosity inside macroporous substrate (zirconium hydrophosphate) or simultaneously in the macroporous substrate and active layer, depending of the particle size (from ≈50 nm up to several microns). Precipitation of the inorganic constituent is considered from the point of view of Ostwald-Freundlich equation. Such processes as pressing test in deionized water and filtration of corn distillery at 1-6 bar were investigated. Theoretical model allowing to establish fouling mechanism, was applied. It was found that the particles both in the substrate and active layer prevent fouling of the membrane with organics and provide rejection of colloidal particles

Electro-deionization of Cr (VI)-Containing Solution. Part I: Chromium Transport through Granulated Inorganic Ion-Exchanger

Somer Symposium 2007 -- MAY 14-15, 2007 -- Middle East Tech Univ, Ankara, TURKEYWOS: 000260209200002Kinetics of Cr (VI) -> OH(-) exchange on both hydrogel and xerogel of hydrated zirconium dioxide was investigated. Self-diffusion coefficient of Cr (VI) species has been determined by analysis of kinetic curves. Transport of Cr (VI) anions through the inorganic ion exchangers under the influence of applied voltage was also researched. In the case of hydrogel, the ions are transported mainly through the solid phase. Diffusion coefficient of chromate anions through this material was estimated as 9.00 x 10(-12) m(2) s(-1). This is in agreement with self-diffusion coefficient of Cr (VI) obtained from kinetic measurements (1.60 x 10(-12)-9.92 x 10(-12) m(2) s(-1)). Owing to the rather high mobility of Cr (VI) through hydrogel of hydrated zirconium dioxide, this material was recommended for electro-deionization processes. On the other hand, the use of polymer anion-exchange membrane must be excluded to prevent poisoning of the inorganic ion exchanger with Cr (III) cations to be formed during chemical interaction of Cr (VI) with organic materials