How can silica be removed from water?
Silica is present in two forms: reactive silica (single unit), and colloidal silica (multiple units). a.. Colloidal silica has virtually no ionic character, but has a relatively large size. Colloidal silica can be removed by fine mechanical barriers, such as reverse osmosis. It can also be reduced by agglomeration techniques, such as used in a clarifier. Techniques which rely on ionic charge, such as ion exchange and continuous deionization (CDI), have very little impact on removal of colloidal silica. b.. The single-unit reactive (ionic) silica is much smaller than colloidal silica. As a result, most mechanical removal techniques such as flocculation, clarification, filtration and flotation are not capable of removing this species. Technologies that allow removing silica are Reverse Osmosis, Ion Exchange and Continuous Deionization.
