| The words 'Reverse Osmosis' have become | | | | allowing the flow of water to pass through at a |
| increasingly frequent in our vocabulary. For some | | | | reasonable rate. |
| people the words conjure up distant memories of | | | | This had an enormous impact worldwide, being |
| school chemistry lessons but how many of us | | | | used in the home and on a much larger scale in |
| know that in the present day, it is a process | | | | desalination plants in some desert areas. Much of |
| which can be simply incorporated into everyday | | | | the Middle East is now serviced by huge |
| life as a lifestyle choice and in the common pursuit | | | | desalination plants, providing clean fresh drinking |
| of a healthier life. | | | | water to households and to farming communities |
| What is Reverse Osmosis? | | | | for the growing of crops. |
| Osmosis is a natural process occurring in both | | | | Uses of Reverse Osmosis |
| plants and the human body where semi | | | | On varying scales in the 21st century, this filtering |
| permeable membranes in the human body can be | | | | process is used in increasingly different fields. It is |
| found both in the digestive tract and in the lungs. | | | | now very much less expensive and more |
| It is where water from a dilute solution becomes | | | | accessible to a range of users. For example; |
| a solute, a more concentrated solution having | | | | * Families. Units can easily be installed under the |
| passed through a semi permeable membrane. | | | | sink in a kitchen to provide pure drinking water |
| Semi-permeable membranes are very thin layers | | | | * Businesses are turning to plumbed in water |
| of material (cell membranes are semi-permeable) | | | | coolers in their offices as they are simple to use, |
| which allow some things to pass through them | | | | cost less than bottled water and do not require |
| but prevent other things from passing through. | | | | floor storage for bottles |
| For example, cell membranes will allow small | | | | * The armed forces use a basic reverse osmosis |
| molecules like water, oxygen, carbon dioxide, | | | | filter in their jungle and desert packs so that their |
| amino acids, glucose etc. to pass through. Cell | | | | soldiers can clean the drinking water to lesson the |
| membranes will not allow larger molecules such as | | | | risks of water borne diseases, |
| protein, starch, sucrose etc. to pass through. | | | | * Submarines. It is a process used on submarines |
| Reverse Osmosis is where the natural occurring | | | | to ensure a regular supply of clean water when |
| process is reversed by applying pressure to the | | | | the vessel is submerged for many months on |
| fluid on the solute side of the semi permeable | | | | end. |
| membrane. This means that water entering | | | | * Car washes. Due to the low mineral content, it |
| through a unit is purified and up to 96% of | | | | is often used in the last rinse in car washes |
| contaminants, heavy metals, turbidity etc are | | | | * The food industry and in particular, in the |
| removed producing high quality water for a vast | | | | chemical and pharmaceutical industries use the |
| range of users. | | | | process extensively. |
| Origins | | | | * Tropical fish. The filters are used in the aqua |
| The whole process began in the 1940's, funded | | | | marine industry and in the keeping of tropical fish. |
| by the Kennedy administration in the US. The aim | | | | * The medical community particularly kidney |
| was to find a way of making pure water from | | | | dialysis units |
| saline water. This was linked to the Space | | | | * Alcohol. The increasing use in the production of |
| program and the idea that once on the moon, | | | | alcoholic spirits |
| vegetation could be planted. | | | | This process has revolutionized water purity and |
| Since the late 1950's scientists have been able to | | | | where the technology was once only available for |
| develop synthetic membranes that can duplicate | | | | industrial use due to its expense, it is now |
| some of what nature does so well. The process | | | | accessible to everyone who chooses water purity |
| was refined when a semi permeable membrane | | | | for optimum health. |
| was engineered, capable of rejecting salt and | | | | |