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Researching Osmosis Plus Reverse Osmosis
Author : Petro Solt
Submitted : 2011-10-19 Word Count : 870 Popularity: Not Rated
Tags: reverse osmosis, osmosis, fresh water, water purifying
To grasp reverse osmosis it's important to check out the process of osmosis first. Osmosis takes place effortlessly in nature in example flowers, where water flows from the outside of plant cells through the cell membrane into the plant cell - this procedure adds to the pressure against the cell wall until it equates to the osmotic strain, thereby setting up a steady state, meaning the stem (the collection of plant tissues in the stem) will be rigid. Think of the stem of a Barberton daisy which is a longish stem and rigid enough to vary the blossom. The solidity of the stem is therefore attributable to water flowing through the membranes of the stem cells, till the pressure outside and inside cells are equal and therefore creating a steady state or rigidity of the stem. A further instance of osmosis is the capability of plant roots to get water from the soil as water would go into the roots through a process of osmosis.
Reverse osmosis, in the above illustration, therefore, will be the flow of waters from the stem cells, through the cell membrane to the outside of the cells allowing the stem to wilt. This subject matter and process is rather an intricate issue of biochemistry and biology and the above description has been greatly refined but will suffice for the purpose of this discussion.
The process of reverse osmosis, in commercial purposes, clearly needs different technology than that of the example of a daisy. In commercial reverse osmoses the flower cell membrane will be replaced by a semi-permeable membrane. What this means in practice is that dependant upon the application, the membrane pores (holes) can be of various sizes to allow the flow of fluid with various size particles through the membrane. Because of this two different applications may require diverse membranes with different size pores.
So, then what is the application of reverse osmosis in our lives and from a business oriented point of view? We all things considered are not Barberton daisies Well, the most typical application is the desalination of seawater. The natural flow of water will be from the weaker solution (of say salt) to the stronger solution - consequently the weaker solution (the more pure water) will move to the stronger solution (salt water) creating a weaker solution of salt water but salt water none the less. In reverse osmosis the process needs to be turned around, whereby we'd force the saltier solution to flow to the fresher solution by making use of pressure, hence the semi permeable membrane will allow water to flow to the fresher solution, but will retain the larger salt molecules. This way the end result is fresh water.
A common application of reverse osmosis can be found in many homes where people feel that their drinking water is not pure. A device can then be fitted to their water inlet which through the process of reverse osmosis will purify the water. Our larger cities, however, provide safe and pure (+-97%) water for drinking and usually there would be no need to further purify the water. In fact the municipalities claim that by further "purifying" water necessary salts and minerals are obtained from the water making it less beneficial.
On farms which experience brackish or impure water such set up, however could possibly not only advantageous but necessary.
Author's Resource Box
For more information about reverse osmosis and also desalination, click the relevant link