Multimedia Filtration (MMF) is often used upstream of RO/NF to remove suspended solids that can cause plugging of membrane feed channels and damage the membrane surface.  However, MMF media is only efficient at removing particles larger than 20 – 50 microns.   AWC has developed a line of membrane compatible organic and inorganic coagulants that agglomerate smaller silts, clays and colloids into larger clusters that are more efficiently filterable.  All polymers have been tested extensively to ensure safe use with RO/NF membranes even in case of slight overdosing.