COLLOIDAL FOULING OF REVERSE OSMOSIS MEMBRANES.

Small colloidal particles intermediate in size between suspended solids and true dissolved solids have been causing serious problems to many reverse osmosis systems throughout the world. These tiny negatively charged particles become concentrated at the surface of the membrane during the reverse osmosis (RO) process and begin to coagulate, plugging the membrane. In order to prevent this from happening, it is suggested that the R. O. pretreatment system be designed properly. If the pretreatment is not adequate, it can lead to high maintenance costs and an increase in membrane replacements.