RO/UF Membranes

RO/UF Membranes Water treatment processes employ several types of membranes. They include micro-filtration (MF), Ultrafiltration (UF), reverse osmosis (RO), and nanofiltration (NF) membranes. MF membranes have the largest pore size and typically reject large particles and various microorganisms. UF membranes have smaller pores than MF membranes and, therefore, in addition to large particles and microorganisms, they can reject bacteria and soluble macro-molecules such as proteins. RO membranes are effectively non-porous and, therefore, exclude particles and even many low molar mass species such as salt ions, organics, etc. NF membranes are relatively new and are sometimes called “loose” RO membranes. They are porous membranes, but since the pores are on the order often angstroms or less, they exhibit performance between that of RO and UF membranes.