Osmosis is the process by which water molecules move from a region where they are highly concentrated to a region where they are lowly concentrated, through a semi-permeable membrane. So it is basically diffusion through a semi-permeable membrane. The membrane permits the passage of water molecules but ions are restricted due to their size. When sufficient pressure is applied to the semi-permeable membrane on the side that is more concentrated, the process can be reversed. This would create a situation where the molecules will be moving from a region of low concentration to a region of higher concentration. They would thus be moving against the concentration gradient. This is what is referred to as reversed osmosis. The principle is the reversal of basic osmosis, and was first demonstrated in the late 1950s.
The process can be applied to water filtration, both small or domestic scale and commercial scale. It can also be used to extract water from different solutions where it is considered an impurity. It is mostly applied when water contains Fluoride, which is an undesirable compound in water. To purify or filter the water to make it fluoride-free, the water can be subjected to the process. It can also be used to remove other impurities from water. It is one of the most effective methods of purifying water. It is also ideal for the desalination of sea water to make it usable.
A filtration system that uses this principle operates very simply. Pure water is pushed by pressure through the semi-permeable membrane, leaving impurities behind. This way various impurities such as viruses, bacteria and pesticides are separated from the pure water molecules. The impurities will of course build up and clog the system if not removed, so the membrane is flushed continuously to dislodge and remove them. The water used to flush is impure but can be used for other domestic purposes. This minimises wastage. Since the cleaning process is automatic, the membrane cartridge has a much more extended service life than a normal filter cartridge.
The system includes a sediment filter and a carbon filter that remove large molecules and smaller molecules not captured by the membrane, respectively. It is a fool proof system.
The flow rate is about 3-10 litres/hour, but the presence of a pressurised storage tank solves the problem of low yield.
In terms of the purity of water produced, efficiency and convenience, reverse osmosis is superior to other water filtration systems.
The process can be applied to water filtration, both small or domestic scale and commercial scale. It can also be used to extract water from different solutions where it is considered an impurity. It is mostly applied when water contains Fluoride, which is an undesirable compound in water. To purify or filter the water to make it fluoride-free, the water can be subjected to the process. It can also be used to remove other impurities from water. It is one of the most effective methods of purifying water. It is also ideal for the desalination of sea water to make it usable.
A filtration system that uses this principle operates very simply. Pure water is pushed by pressure through the semi-permeable membrane, leaving impurities behind. This way various impurities such as viruses, bacteria and pesticides are separated from the pure water molecules. The impurities will of course build up and clog the system if not removed, so the membrane is flushed continuously to dislodge and remove them. The water used to flush is impure but can be used for other domestic purposes. This minimises wastage. Since the cleaning process is automatic, the membrane cartridge has a much more extended service life than a normal filter cartridge.
The system includes a sediment filter and a carbon filter that remove large molecules and smaller molecules not captured by the membrane, respectively. It is a fool proof system.
The flow rate is about 3-10 litres/hour, but the presence of a pressurised storage tank solves the problem of low yield.
In terms of the purity of water produced, efficiency and convenience, reverse osmosis is superior to other water filtration systems.