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Characteristics of Filter Cake Exfoliation in Upward Ultrafiltration of Nanoparticle Suspensions
Department of Chemical Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
* Author to whom correspondence should be addressed.
Received: 26 November 2010; in revised form: 6 January 2011 / Accepted: 17 January 2011 / Published: 20 January 2011
Abstract: Downward and upward ultrafiltration (UF) was performed using the suspensions of nanosized colloidal silica with different particle diameters and their filtration rates were compared. In downward UF, the filtration rate decreases as the particle diameter decreases because the specific filtration resistance of the filter cake becomes significantly higher. In contrast, the filtration rate in upward UF increases with the decrease in the particle diameter because the filter cake consisting of small particles is exfoliated much more easily under the influence of gravity than that of large ones. In order to evaluate the characteristics of the filter cake exfoliation, the steady filtration rate in the upward mode was measured. The steady filtration rate has a tendency to decrease with particle concentration as well as mean particle diameter. Therefore, when the small particles are added into a given concentration of large particle suspension, the mean particle diameter decreases and the total particle concentration increases due to the dosage of small particles. This results in a maximum of the steady filtration rate at a certain dosage of small particles. Moreover, an estimation equation was proposed for predicting the steady filtration rate in upward UF of colloidal silica suspensions with various mean particle diameters and total particle concentrations.
Keywords: nanoparticle; ultrafiltration; filter cake exfoliation; steady filtration rate; binary mixture
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MDPI and ACS Style
Mukai, Y.; Nishio, A. Characteristics of Filter Cake Exfoliation in Upward Ultrafiltration of Nanoparticle Suspensions. Membranes 2011, 1, 59-69.
Mukai Y, Nishio A. Characteristics of Filter Cake Exfoliation in Upward Ultrafiltration of Nanoparticle Suspensions. Membranes. 2011; 1(1):59-69.
Mukai, Yasuhito; Nishio, Aya. 2011. "Characteristics of Filter Cake Exfoliation in Upward Ultrafiltration of Nanoparticle Suspensions." Membranes 1, no. 1: 59-69.