13. Reverse Osmosis System
Our RO can treat up to 1800 Gallons of water per day—easily meeting the demand of a large home 400 to 600 GPD consumption. Because of the comprehensive pre-treatment, our product recovery rate is unique in its very healthy ratio and is greener than any competitive whole home system. Will remove upward of 98% of all dissolved solids, organic bacteria and residual hardness minerals and metals. In areas of the US where all water is reclaimed, nuisance pharmaceuticals are discharged here. Dr. Zoltan Rona has authored an excellent paper on ‘Pure Water’ recommending in no uncertain terms against its continued consumption. According to the U.S. EPA, “Distilled water (which is identical to RO water ~Ed), being essentially mineral-free, is very aggressive, in that it tends to dissolve substances with which it is in contact. Notably, carbon dioxide from the air is rapidly absorbed, making the water acidic and even more aggressive. Many metals are dissolved by distilled water.” Dr Rona adds; “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 distilled water.” As Reverse Osmosis produced water is identical in nature to distilled water we can make the same assumptions
Reverse Osmosis (RO)
Nature dislikes imbalance, and reverse osmosis takes advantage of this natural need. Osmosis is the movement of water across a semipermeable membrane from the side that is less concentrated, and more pure to the salty, more concentrated side. This continues until either the concentration is equal, or the pressure on the concentrated side becomes strong enough to stop the flow.
In reverse osmosis the process happens in reverse, due to the pressure of a high pressure pump. The pump applies a strong pressure to the concentrated side, forcing water molecules over to the pure side, and leaving the salt, minerals and other impurities to be removed as waste. While the percentage of feedwater to pure water is large, the process is very efficient in removing contaminants. The following chart reflects expectations
Reverse Osmosis (RO) Systems are often used to:
?????Dramatically reduce the Total Dissolved Solids (TDS) from process water by 98% to 99%
?????Remove certain hazardous elements and contaminants from dissolved in process water
?????Purify water to high levels required by specific downstream processes
Reverse Osmosis (RO) operates on the same principal as the semi-permeable membranes present in every living cell. RO Membranes are permeable only to water molecules, and under pressure, split a feedwater stream into two parts; purified water, called permeate, and the rejected contaminants, called concentrate. Due to the fact that water fed into an RO is split into two paths, an RO, unlike other conventional water treatment technologies, may be described in terms of its efficiency in “Recovery” of purified water from a contaminated feedwater stream.
Note: Water purification by RO takes place at the molecular level; therefore the efficiency and lifespan of the RO Membranes is directly correlated to the quality of the upstream filtration, or Pretreatment.
For Those who would really like an education.
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ITG SUBJECT: REVERSE OSMOSIS
Introduction
Reverse osmosis (RO) has been known for more than a century, but it did not become a commercial process until the early sixties when a special membrane was developed (1,2,3,4). Because RO operates at a comparatively low temperature and is relatively energy efficient, it is employed in various applications, e.g., desalination, treatment of waste water, reclamation of minerals, concentration of whey and other food products, and purification of water (5,6). In recent years, RO has been used increasingly in making processed water for dialysis in hospitals and for certain cosmetics and drugs by pharmaceutical manufacturers (7,8). In addition to these applications, RO is capable of producing water of sufficient purity to be used as Water For Injection (WFI) and for the preparation of parenteral solutions (9,10,11,12). This ITG will focus on the chemical and microbiological quality of water produced by reverse osmosis.
Definition and Operating Principle
Reverse osmosis is a process which uses a membrane under pressure to separate relatively pure water (or other solvent) from a less pure solution. When two aqueous solutions of different concentrations are separated by a semi-permeable membrane, water passes through the membrane in the direction of the more concentrated solution as a result of osmotic pressure (Figure 1). If enough counter pressure is applied to the concentrated solution to overcome the osmotic pressure, the flow of water will be reversed (Figure 2).
Water molecules can form hydrogen bonds in the RO membrane and fit into the membrane matrix. The water molecules that enter the membrane by hydrogen bonding can be pushed through under pressure. Most organic substances with a molecular weight over 100 are sieved out, i.e., oils, pyrogens and particulates including bacteria and viruses (13).
Salt ions, on the other hand, are rejected by a mechanism related to the valence of the ion. Ions are repelled by dielectric interactions; ions with higher charges are repelled to a greater distance from the membrane surface. Monovalent ions such as chloride ions will not be rejected as efficiently as, for example, divalent sulfate ions. The nominal rejection ratio of common ionic salts is 85 – 98%.
Membrane
The majority of the commercially manufactured RO membranes are made from cellulose acetate, polysulfonate, and polyamide. Many other kinds of membrane made of a single polymer or a copolymer are also available for specific purposes. The membrane consists of a skin about 0.25 microns and a support layer about 100 microns. The skin is the active barrier and primarily allows water to pass through.
Two types of RO construction are commonly used: 1. spiral wound —sheets of membrane sandwiched with mesh spacers are connected and wound around a permeate tube; and 2. hollow fiber. Either of these modules is assembled into a pressure housing. Schematics of these two types of membrane modules (permeators) are shown below (Figures 3 and 4).
Contact: Dave Loveday
Water Quality Association
International Headquarters & Laboratory
4151 Naperville Road, Lisle, Illinois 60532-3696 USA
Email: DLoveday@wqa.org
Telephone: 630 505 0160
Faxsimilie: 630 505 9637
Water quality association Press Release
For IMMEDIATERelease – May 14, 2008
Reverse osmosis systems remove nitrates
New Mexico consumers can protect themselves
LISLE, Illinois — Residents of Torrance County worried about nitrates in their water can protect themselves with the use of a home-based reverse osmosis system.
Responding to reports that nitrates were found in water supplied by Homestead Water Company, the Water Quality Association reminds citizens that RO units effectively remove the element. New Mexico’s Environment Department announced the finding on nitrates last week.
WQA tests and certifies products for effectiveness. The association uses independent standards established by the NSF International/American National Standards Institute (NSF/ANSI).
Nitrates which are ingested by infants or young farm animals are changed into dangerous nitrites, which can seriously affect the blood’s ability to release oxygen. Once these nitrites enter the circulatory system, they combine with the blood’s hemoglobin and prevent life-sustaining oxygen from being carried to body tissues.
To find a directory of certified RO units, visit wqa.org. The “Gold Seal Certified Products” button leads to a “Search by Reduction Claims” function. By typing “nitrates,” consumers can find a full list of RO units certified for effective nitrate reduction performance.
For more information or to find locally certified water professionals and Gold Seal certified products, visit wqa.org. The Water Quality Association is a non-profit international trade association representing the residential, commercial, industrial and small community water treatment industry. WQA is a resource and information source, a voice for the industry, an educator of professionals, a laboratory for product testing, and a communicator with the public. WQA has more than 2,500 members nationwide
. Now, water simply purified still isnt so good for you.
Most European countries have banned the use of pure water (water treated byDistillation or reverse osmosis) as drinking water. Lack of minerals (trace elements) Essential to human body makes the ban reasonable. The non-nutritious pure water Is not good for drinkers’ health. In the long run, the water will expel existing minerals Out of the human body.Currently, over 10 minerals are believed to be essential to human body. Many of dietetics research reports show that drinking water provides the essentials rather than food. In the 80s, United Kingdom conducted a longitudinal epidemiologic survey of cardiovascular disease mortality rates of residents in 253 municipalities. The survey demonstrates that the mortality rates negatively correlate with water mineral levels the surveyed residents drink. The researchers found 10% to 15% more cardiovascular deaths in soft water areas than in hard water areas????. Another similar survey performed for the period 1969-1978 in Sweden suggests a significant inverse relationship between the magnesium level in drinking water and sudden death from cardiovascular disease. In addition, a US investigation based on data on water quality obtained from top 100 biggest cities demonstrates 10% to 25% lower cancer mortality in hard and weak alkali water areas than in other areas????. However, in normal water minerals have a tendency to combine with salt-forming anions to form crystallized substances (scale). It is hard for the human body to absorb the crystallized minerals.
By NEED, Nion Negative Ion Drinking Water containing constantly ionized minerals ensures higher absorption