MY RESPONSE DOESN'T ADDRESS THE QUESTION DIRECTLY, BUT R.O. COULD ACT AS A STAND ALONE TREATMENT FOR SILICA. OR AS A PRETREATMENT COULD SAVE $ IN RESIN REGENERATION. OF COURSE APPLICATION MIGHT OR MIGHT NOT WARRANT R.O. BOTH FROM A SPACE AND WATER CONSUMPTION STANDPOINT. YOU MIGHT WANT TO DETERMINE  WHAT THE PRODUCT WATER SHOULD BE IN SILICA CONCENTRATION BEFORE CONSIDERING R.O. AS A STAND ALONE TREATMENT. THE REJECTION WOULD BE IN THE 90% RANGE.

 

GARY L. LINDSEY

CWS VI CI

To select the most suitable water treatment process, we have to know what the alkalinity of the raw water is and the flow rate, plus what is the residual silica level in the product water you can accept.

Silica comes in two forms, one is the colloidal silica, and the other is the ionized (dissolved) or reactive silica.

As I say above, alkalinity is a problem because, and as it "accumulate" in the resin beads, during exhaustion of the resin bed, it "regenerates" the silica, displacing it, downward in the resin bed, to the point where we have an early silica leakage of silica in the product water, followed by a drop in the pH.

I would not recommend RO, because colloidal silica tends to "be filtered" by the RO membrane, so it is necessary to feed a "dispersing agent" to prevent the precipitation on the surface of the RO membrane.

I know there are some RO membrane specially manufactured to support this silica.

We also need what the use of the Silica Free water is.

I would like to receive some comments on my comments.