Understanding the differences between microfiltration, ultrafiltration, nanofiltration, and reverse osmosis helps you choose the right membrane process.
Membrane filtration has transformed water treatment by enabling precise separation of contaminants based on molecular size. Four main technologies span a wide range of removal capabilities: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO).
Microfiltration (MF) operates at the lowest pressures (0.1–0.3 bar) and removes particles, suspended solids, bacteria, and protozoa down to about 0.1 microns. It does not remove viruses or dissolved contaminants. MF is ideal as pre-treatment before RO, or as a final polishing step where only particle removal is required.
Ultrafiltration (UF) removes viruses, colloids, proteins, and high-molecular-weight organics down to 0.01 microns at modest pressures. UF is widely used for drinking water, food processing, and as pre-treatment for NF or RO systems. Its tight pore structure makes it an excellent barrier against biological contaminants.
Nanofiltration (NF) bridges the gap between UF and RO. Operating at 5–15 bar, it removes divalent ions (hardness), color, pesticides, and some monovalent ions. NF is used for water softening, color removal from surface water, and selective ion removal where full demineralization is not required.
Reverse Osmosis (RO) operates at the highest pressures and removes virtually all dissolved salts, organics, bacteria, and viruses, producing high-purity permeate. RO is the preferred technology for boiler make-up water, pharmaceutical production, beverage manufacturing, and desalination.
Aqua Global designs integrated membrane systems combining these technologies to achieve specific water quality targets efficiently and economically.