Of late, Reverse Osmosis Water Treatment Systems have been widely received by consumers who need to find more complete solutions to treat and filter contaminated water. Sometimes the Reverse Osmosis is also known by its other name, "Ultra-Filtration". This technology has been in use in many desalination plants around the world but has only become truly affordable for use in households quite recently.
The Reverse Osmosis Process
How it works really is quite simple, in short, water molecules are forced through an extremely fine (often 0.0001 micron) semi-permeable membrane by water pressure, its much like a microscopic sieve which can filter almost all contaminants from ions and heavy metals to Volatile Organic Chemicals (VOCs) or even pesticides and micro-organisms.
If looked at with naked eyes the membrane will look almost like a cellophane tape. On one side of the membrane is treated water and the other side is raw water. Under pressure the raw water is "squeezed" through the membrane to create the treated water. An inherent characteristic of Reverse Osmosis systems is that they treat water at a slow rate. As such treated water is normally collected in storage containers or tanks. Rejected impurities on the raw water side are normally washed away in the stream of waste water and aren't accumulated as with a traditional filter.
Reverse Osmosis System Design
Although the Reverse Osmosis concept is very simply, the complete water filtration system is quite complex. Typically, most home Reverse Osmosis water filters are either Point-of-Use (POU) systems which is basically your under-sink or countertop systems which only provide treated water to one or two faucets in the house or Point-of-Entry (POE) systems which are located on the main line supplying the house and will supply treated water for the whole house.
A typical home Reverse Osmosis System normally comprises of:
a) Sediment Filter
b) Activated Carbon Pre-filter
c) Reverse Osmosis Membrane Filter
d) Activated Carbon Post Filter
e) Storage Tank
Maintenance Requirement of a Reverse Osmosis Water Treatment System
All Reverse Osmosis systems must be maintained to ensure reliability and freshness of water. Reverse Osmosis membranes are generally quite fragile and depending on the type of water contaminants passing through the membrane, small tears or rips in the membrane could occur and not be visible to the naked eye which would require water tests to determine.
Bio-fouling is also a risk when water is highly laden with micro-organisms which are blocked by the membrane. To prevent it, the Reverse Osmosis units must periodically be disinfected with chlorine or other biocides, normally provided by the manufacturer.
Things you must know before buying a Reverse Osmosis Water Treatment System
1). What is the quality of your raw tap water?
The very first thing that you must do is to determine the type of contaminant that you would like to treat in your tap water. Generally, the municipal water utilities will provide a water analysis free of charge should you request for one. Once the water analysis is done you can then determine which contaminants are the most dangerous and proceed to decide if you would like to install a Reverse Osmosis system.
Additionally some tests that normally aren't conducted by the municipal water utilities such as tests for coliform bacteria or Total Dissolved Solids (TDS) should be done with the help of a certified laboratory to determine if your Reverse Osmosis water treatment system requires pre or post filters.
2). What type and concentration of contaminant do you expect the Reverse Osmosis System to remove?
When you are considering the purchase of a Reverse Osmosis System you should ask what the "contaminant passage and rejection rates" are for the system in your typical house usage situation. With the report on your tap water contaminants obtained earlier you can also ask for the "contaminant passage and rejection rates" for the specific types of contaminants which will give you a better idea of the treatment capacity of your system. This basically means how much contaminants the system can actually remove after a set time (e.g. ml/hour).
Additionally, some Reverse Osmosis systems can be certified in reduction of specific contaminants if they pass a test by NSF ( www.nsf.org ), most reputable brands would have NSF awarded marks which assure the manufacturer's contaminants reduction claims.
3). How much treated water do you or your household need?
This is where the potential buyer needs to determine if he/she would like treated water house wide (Point-of-Entry) of if they need a faucet specific (Point-of-Use) system. The volume of treated water required should be gauged per day and thus the size of the pump, membrane and holding tank can be determined based on those estimations.
It should be noted that this is particularly important for Point-of-Entry rather than Point-of-Use systems. It isn't that bothersome to wait slightly longer to fill a glass of drinking water compared to waiting to wash soap out of your eyes or to flush the toilet.
4). Reverse Osmosis Water Treatment Systems purchase and maintenance.
Reverse Osmosis systems can generally be bought anywhere from $200 to over $2000 depending on the capacity and treatment requirements of the system. The cost of maintaining the system should also be factored in when deciding on which system to purchase. The costs of maintaining a Reverse Osmosis system also include monitoring water quality; you will also need to periodically replace the membranes and filters (pre and post). Additionally, note that running a high capacity Point-of-Entry Reverse Osmosis system can also increase your water bills and a portion of the water is drained away as waste water.
Reverse Osmosis systems, are slightly more expensive than other systems. Buyers should realize that Reverse Osmosis systems are at the higher end of the home water filtration product spectrum and thus the higher costs and quality.
Health effects from long term drinking of RO water
Studies validate the benefits of drinking RO water when one is seeking to cleanse or detoxify the system for short periods of time (a few weeks at a time).
Fasting using RO water can be dangerous because of the rapid loss of electrolytes (sodium, potassium, chloride) and trace minerals like magnesium, deficiencies of which can cause heart beat irregularities and high blood pressure. Cooking foods in RO water pulls the minerals out of them and lowers their nutrient value.
According to the U.S. Environmental Protection Agency, "RO, being essentially mineral-free, is very aggressive, in that it tends to dissolve substances with which it is in contact.
The most toxic commercial beverages that people consume (i.e. cola beverages and other soft drinks) are often made from RO water. Studies have consistently shown that heavy consumers of soft drinks (with or without sugar) spill huge amounts of calcium, magnesium and other trace minerals into the urine.
The more mineral loss, the greater the risk for osteoporosis, osteoarthritis, hypothyroidism, coronary artery disease, high blood pressure and a long list of degenerative diseases generally associated with premature aging.
A growing number of health care practitioners and scientists from around the world have been advocating the theory that aging and disease is the direct result of the accumulation of acid waste products in the body.
There is a great deal of scientific documentation that supports such a theory. A poor diet may be partially to blame for the waste accumulation. Meats, sugar, white flour products, fried foods, soft drinks, processed foods, alcohol, dairy products and other junk foods cause the body to become more acidic. Stress, whether mental or physical can lead to acid deposits in the body.
There is a correlation between the consumption of soft water (RO water is extremely soft) and the incidence of cardiovascular disease. Cells, tissues and organs do not like to be dipped in acid and will do anything to buffer this acidity including the removal of minerals from the skeleton and the manufacture of bicarbonate in the blood.
The longer one drinks RO water, the more likely the development of mineral deficiencies and an acid state. I have done well over 3000 mineral evaluations using a combination of blood, urine and hair tests in my practice. Almost without exception, people who consume RO water exclusively, eventually develop multiple mineral deficiencies.
Those who supplement their RO water intake with trace minerals are not as deficient but still not as adequately nourished in minerals as their purified water drinking counterparts even after several years of mineral supplementation. One example would be Coca Cola's Disany water. This is a re mineralized RO water.
The ideal water for the human body should be slightly alkaline and this requires the presence of minerals like calcium and magnesium.
RO water tends to be acidic and can only be recommended as a way of drawing poisons out of the body. Once this is accomplished, the continued drinking of RO water is a bad idea.
Water filtered through reverse osmosis is not acceptable for regular use provided minerals are supplemented.
Water filtered through a solid charcoal filter is slightly alkaline. Ozonation of this charcoal filtered water is ideal for daily drinking. Longevity is associated with the regular consumption of hard water (high in minerals).
Disease and early death is more likely to be seen with the long term drinking of RO.
Avoid it except in special circumstances."