Colloidal fouling of reverse osmosis membranes

Abstract 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 R.O. process and begin to coagulate, plugging the membrane. If this fouling is allowed to go on unchecked, the quantity and quality of the product water will begin to deteriorate until the membranes will eventually need to be replaced. 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.