Yoshihiko Nawa

Formation of dynamic UF membrane with fine Zr particles

Abstract The performance of dynamic ultrafiltration (UF) membranes depends on the characteristics of the metal colloids exploited as membrane materials. Due to the lack of chemical and physical stability of metal colloids, membrane performance is not always constant. However, the authors have succeeded in preparing stable inorganic dynamic UF membranes on a porous ceramic support with fine Zr particles prepared by Matijevics method. The deposited layer of the particles produced an excellent rejection ability as an UF membrane. The membranes were superior in stability to conventional metal colloid membranes. The performance of this membrane can be controlled by the Zr particle size and the thickness of the deposited layer.

Preparation of fine zirconium hydrous oxide particles for dynamic ultrafiltration membrane

Abstract Fine and uniform zirconium hydrous oxide particles about 0.03–0.3 μm in diameter could be prepared by Matijevics method in the presence of sulfuric acid. It is possible to control the size of particles by the use of zirconium concentrations in the approximate range (5·10 −4 −5·10 −3 kmol m −3 ) and molar ratios of zirconium to sulfate from about 1.0/0.7 to about 1.0/7.0. The particles are completely amorphous, and the surfaces consist of zirconium, oxygen and SO 2− 4 , as shown by X-ray powder diffractometry and X-ray photoelectron spectroscopy respectively.

Conditions and Mechanism of Dynamic UF Membrane Formation with Fine Zr Particles.

粒径0.03μmから0.2μmのジルコニウム超微粒子懸濁液を濾過することによって, 多孔質支持体上にダイナミック限外濾過膜を形成することができた.本膜の膜性能は, ジルコニウム超微粒子の粒径と堆積層の厚さに依存した.流速2m・s-1以下, 圧力0.5MPa以上の条件で, 超微粒子は支持体上に十分堆積し, 限外濾過膜としての性能が得られた.最適膜形成条件は, 25℃において流速1m・s-1, 圧力0.5MPaであった.Ruthのケーク濾過理論で解析したところ, 最適条件で膜を形成した場合の透過流束の変化を良好に予測することができた.