Method and Apparatus for Purifying the Dispersing Liquid in a Colloidal Dispersion

In a purification system for a colloidal dispersion containing an unwanted dissolved substance (or substances) in the dispersing liquid phase, a filter device comprising:

• a housing including an inlet port for receiving an unpurified colloidal dispersion and an outlet port for discharging a purified colloidal dispersion, the housing further including a semi-permeable filter element that enables the bulk flow of the colloidal dispersion through a first conduit that is in fluid communication with both the inlet port and the outlet port of the housing while permitting the flow of a portion of the unpurified dispersing liquid phase across the filter element and into a second conduit that is also in fluid communication with the outlet port, a back-pressure regulating feature disposed within the first conduit that is used to force a portion of the unpurified dispersing liquid across the filter element and into the second conduit, an adsorptive element that is associated with the second conduit and used to remove the unwanted dissolved substance from the filtered portion of the dispersing liquid, and a mixing chamber disposed downstream of the back-pressure regulating feature whereby the purified dispersing liquid portion from the second conduit is rejoined with the bulk flow of the colloidal dispersion passing through the first conduit prior to being discharged at the outlet port of the housing.