Reverse Osmosis

Reverse Osmosis

Reverse Osmosis is a membrane filtration process to remove dissolved solids from the water. It is mostly used in drinking water treatment by eliminating salts and other constituents. Nowadays the technique is widely used to purify water for industrial, residential, and commercial purposes.

Reverse Osmosis Working Principle

Reverse Osmosis is carried out using an RO semipermeable membrane which acts as a filtration physical barrier. The pressure greater than the osmotic pressure is developed on one side of the solution. The impurities like salts are retained on the membrane and taken forward for further process. During the process, two outlets are generated: one is called permeate and another is reject water. Reverse osmosis takes place when the solvent passes through the membrane against the concentration gradient. It moves from a lower to a higher concentration.

Stages in Reverse Osmosis

• Pre Filtration: In prefiltration, two stages are involved: Sediment filter & Carbon Filter. The Sediment filter removes dust, suspended matter, rust, etc. present in the water & the Carbon filter eliminates volatile suspended solids (VOCs), chlorine, and odor.

Reverse Osmosis Membrane

A Reverse Osmosis system is dependent upon and built around its individual membranes. Each membrane consists of a spiral-wound sheet of a semipermeable material, which varies depending on the application. Membranes are available in 2-inch, 4-inch, and 8-inch diameters, with the 4-inch and 8-inch diameter sizes most commonly used in the water treatment industry.