(251d) Filtration Characteristics of Insoluble and Soluble Colloids

Specific cake resistance using unstirred ?dead-end? constant pressure filtration on an insoluble (titanium dioxide) and a soluble (magnesium hydroxide) colloid have been determined, as a function of pH. The specific cake resistance was correlated across a range of pH conditions with electroacoustic zeta potential measurements. The shear yield stress was also measured as a function of pH for both materials and correlated with the specific cake resistance. These results show that the analytical approach taken for an insoluble colloid is also applicable to a soluble colloid, but over the narrow pH range where the colloid remains insoluble.