December 27, 2011 1:06:51 PM IST
Membranes are a selective barrier used in anything. The idea of membranes has been derived from the biological cell membrane. It is an artificial polymeric barrier used to stop any kind of dust or dirt from getting further deep into any kind of system.
RO means Reverse Osmosis. Reverse osmosis is a method of filtration. This filtration system removes any kind of big molecules by applying pressure on one side of the membrane. The use of the RO system is applied in filtering the water in the following forms:
- Drinking water
- Boiler feed water
- Sea water
- Ultra pure water
- USP water
- Water reuse
- Brackish water
- High flow commercial application
Reverse Osmosis system is the most effective system for any kind of cleaning of water. The basic filtering media is the RO membrane.
How does an RO membrane work?
The RO membrane is a membrane that is a form of a filter in general terms. The pore sizes of its elements can be between 0.1 to 5,000 nanometers (nm). The size depends upon the component being filtered from the water. The smallest filter can restrict minerals and salts to pass through the membrane and purify the water through a pressure system. The pressure system works by applying pressure to the water which forces the water to gush through the membrane which in the process purifies it and cleans the water. The membrane systems are strong enough to filter different bacterias and germs from the water as well.
The commercial RO membranes are available in the following forms:
- Tap water RO membranes: This is used for small usage systems. Like small commercial water usage, this system is able to purify less than one gallon of water in a minute.
- Brackish water RO membranes: This kind of system is used for light industrial systems. It needs high rejection and operating pressures as low as 200 psig.
- Low energy RO membranes: This kind has the most usage that is used for high purity water.
- High flow rate RO membranes: These are used for medical places. Lots of pure water is required in hospitals, dialysis clinics.
- Nano RO membranes: They pass monovalent salts through the RO membrane and remove organics with molecular weights greater than 300 amu.
- Sea water RO membranes: This kind of RO membranes are the best and very high in quality as they clear all kind of salts in the sea water and desalinate it completely for easy drinkable human use.
The life of a commercial RO membrane:
Normally the life expectancy of any RO membrane is about 2years. After 2 years or maybe a little more or less they loose their way of purifying completely. They should be changed by the time they loose their life so that the water purification system stays. The water after purification gets clean and leaves behind a whole mass of different particles like oil, silica, clay, iron, sulfur and acids.