What is the Reverse Osmosis (RO) Process?
Reverse Osmosis Systems (RO) : Water pressure is used to force water molecules through a very fine membrane leaving the contaminants behind. Purified water is collected from the “clean” or “permeate” side of the membrane, and water containing the concentrated contaminants is flushed down the drain from the “contaminated” or “concentrate” side. The average RO system is a unit consisting of a sediment/chlorine pre filter, the reverse-osmosis membrane, a storage tank, and an activated-carbon post filter.
Reverse osmosis removes salt and most other inorganic material present in the water, and for that reason, RO lends itself to use in places where the drinking water is brackish (salty), contains nitrates or other dissolved minerals which are difficult to remove by other methods.
Stages of Filtration
The modern RO system is a unit consisting of a sediment pre-filter to remove particulates, turbidity, sand and rust; an activated carbon pre-filter to remove the chlorine, pesticides, herbicides, disinfectants, and VOCs which might otherwise damage the reverse osmosis membrane; the reverse-osmosis membrane which removes virtually everything such as heavy metals, lead, salt, chromium and dissolved solids; a storage tank, and an activated-carbon post filter. The carbon post filter or polishing filter is necessitated by the demineralized, slightly acidic RO water attacking the rubber inside the storage tank, dissolving some of the rubber. This can be avoided by remineralizing the water prior to storage.
Sediment Stage: removes rough particles, sand and rust.
Carbon stage: removes chlorine and chemicals which would otherwise damage the TFC reverse osmosis membrane.
Multiple carbon stages my be necessary at this point depending on the carbon quality and contact time.
Reverse osmosis stage: removes dissolved solids nd virtually everything larger than the water molecule itself. This is where the bulk of the purification is accomplished.
Remineralization Stage: water purified by reverse osmosis is highly pure and slightly acidic. The mineralizer system then remineralizes with calcium and magnesium to balance the pH, improve the taste and introduce healthy minerals.
Optional or application specific water treatment stage(s): UV filter to destroy microorganisms, nitrate/arsenic/fluoride/deionization selective filters to remove whatever small amount remains of these contaminants.
Final Carbon stage: also known as a “polishing” filter this carbon filter removes any tastes or odors the acidic RO water has “picked up” from the storage tank. In other words the acidic water produced from systems without the Artesian Full Contact technology will dissolve some of the rubber in the storage tank which the final carbon filter then removes.
Reverse Osmosis Purity
Reverse osmosis removes salt and most other dissolved inorganic material present in the water, and for that reason, reverse osmosis water filters are usually used in places where the drinking water is brackish (salty), contains nitrates, radionucliatides, heavy metals or other dissolved minerals which are difficult to remove by other methods. Using a quality carbon filter to remove any organic materials and chemicals that get through the sediment pre-filter, in conjunction with RO produces water with a purity that approaches distilled water is important for any house water filtration system. Microscopic parasites (including viruses) are usually removed by RO units, but any defect or micro-tear in the membrane will allow these organisms to pass into the ‘clean” water. This is why RO systems are not rated to remove microorganisms except when an Ultraviolet Light filter is incorporated into the system.
Reverse Osmosis Efficiency and Waste
Though slower than a water filter, RO systems can typically purify more water per day than distillers. Also, they do not use electricity, but RO systems do produce waste water. One or more gallons of concentrated waste water are flushed down the drain for every gallon of filtered water that is produced.
The different ways to dispose of Brine Waste:
Drill deep disposal well below the fresh water zone. In California this would be a class II disposal well.
Passive evaporation ponds.
Wetlands with a plant life designed to cleanse high salts in waste water.
Mix concentrate from R.O. with well or city water and lower the salts to expectable levels to release in a river or stream.
If you have any Questions whatsoever PLEASE FEEL FREE to call Artesian Water Well & Filter Services at 951-698-9040