What Is the Difference Between Ultrafiltration Membrane and Reverse Osmosis Membrane?

Reverse osmosis membrane and ultrafiltration membrane

The reverse osmosis membrane is an artificial semipermeable membrane with certain characteristics that simulates biological semipermeable membranes. The diameter of the surface micropores is generally between 0.5-10nm, and the permeability is related to the chemical structure of the membrane itself. The ultrafiltration membrane is a microfiltration membrane with a uniform pore size and a rated pore size range of 0.001-0.02 microns. The reverse osmosis membrane is generally made of polymer materials.

By applying appropriate pressure on one side of the ultrafiltration membrane, solute molecules smaller than the pore size can be screened out to separate particles with a molecular weight greater than 500 Daltons (atomic mass unit) and a diameter greater than 10 nanometers. The ultrafiltration membrane is one of the earlier developed polymeric separation membranes, and ultrafiltration equipment was industrialized in the 1960s.

Characteristics of reverse osmosis membrane and ultrafiltration membrane

The reverse osmosis membrane should have the following characteristics:

• High desalination efficiency under high flow rates.

• High mechanical strength and service life.

• Functions can be achieved under low operating pressure.

• Resistant to the effects of chemical or biochemical action.

• Minimally affected by factors such as pH and temperature.

• Easily sourced raw materials, easy processing, and low cost.

Application characteristics of ultrafiltration membrane

• No qualitative changes occur during the ultrafiltration process, and it can run stably at room temperature.

• Precision equipment with a small footprint, easy to operate.

• Simple ultrafiltration separation process, highly automated equipment.

• Can classify substances of different molecular weights for processing.

• Strong applicability to water quality, widely used in water treatment technology.

Application scope of reverse osmosis membrane and ultrafiltration membrane

The application scope of the reverse osmosis membrane includes the fields of electric power, petrochemical, steel, electronics, medicine, food and beverage, municipal and environmental protection. It plays an important role in seawater and brackish water desalination, boiler feedwater, industrial pure water, and electronic-grade ultrapure water preparation, production of drinking purified water, wastewater treatment, and special separation processes.

The application scope of ultrafiltration membrane includes the reverse osmosis pretreatment and terminal treatment of pure water and ultrapure water preparation processes, separation of bacteria, heat sources, colloids, suspended impurities, and large molecular organic substances in industrial water, purification of drinking water and mineral water, concentration, purification, and clarification in the fermentation, enzyme preparation, and pharmaceutical industries, concentration and separation of soy products, dairy products, sugar refining, liquor, tea juice, vinegar, and other industries, industrial wastewater treatment and purification of domestic sewage and recycling, and recycling of electrophoretic paint.