Reverse osmosis (R/O) is a water treatment process in which water is forced through a semi-permeable membrane that has very small holes or "pores". Clean water passes through and impurities that are too big to pass through the membrane are left behind and flushed away. According to Engineering at Dartmouth, reverse osmosis was actually invented by a Frendh physicist, Jean Antoine Nollet in the eighteenth century. It wasn't until 1969 though that it started to be used as a commercial application when Dean Spatz used the process to separate maple sugar from the sap. From there it has become a key process used in water filtration. If you would like to find out how reverse osmosis can improve the quality of your water, contact us at WaterSmart.
How Does Reverse Osmosis Work?
Reverse osmosis systems purify water by forcing pressurized water through a very fine, plastic membrane. If the raw water being treated comes from a well or another private source, disinfection and pre-filters (to remove chlorine and/or particulates/sediment) may be needed in advance of the R/O unit to remove contaminants that can foul or damage the membrane. The following video from the Sydney Water explains how reverse osmosis works on a large scale.
Stages of reverse osmosis:
During the initial filtration stage, tap water or well water (pressurized by a booster pump) is passed through a particle filter (a pre-filter) that removes silt, sediment, sand, and clay particles that might clog the R/O membrane.
The water is then forced through an activated carbon filter that traps minerals and contaminants such as chromium, mercury, copper, chloramine and pesticides. It also removes chlorine, which is important, as chlorine will shorten the life of the membrane.
Water is transferred under pressure into the R/O module, allowing only clean water to pass through the small pores in the membrane. Impurities unable to pass through the membrane are left behind and flushed down the drain.
Treated water is then sent to a storage tank.
Treated water is passed through an activated carbon filter before use to further improve the water's taste and smell. The Duro Reverse Osmosis System, available at WaterSmart, features pre and post carbon block filtration. The carbon filter acts as a complementary measure to block dangerous chemicals like pesticides, herbicides, and chlorine, which are small enough to pass through the reverse osmosis filter.
Water that contains manganese, hydrogen sulphide or iron should be pre-treated to extend the life of the membrane. A dealer can recommend the pre-treatment needed.
Note: Reverse Osmosis units produce no noise other than the sound of water discharging into the drain (usually a sink or a floor drain).
Do I Need a Reverse Osmosis Unit?
It is presumed that the water you are using meets all health regulations and is known to be safe. If your municipality or utility supplies your drinking water, it is likely that you do not need a reverse osmosis unit. Municipally supplied drinking water is microbiologically safe. It is treated to meet health and aesthetic requirements, and is subject to routine testing for microbiological contamination.
If you obtain drinking water from a private supply such as well, it may not be safe from microbiological, chemical, or other types of contamination. Drinking water from private sources should be tested periodically to determine if treatment is required; and, if so, for what specific contaminants or minerals.
Water chemistry is complex and no single water treatment device can be used to remove all types of substances from water. Different drinking water treatment devices have their own advantages and disadvantages. Each household must individually determine if there is a need for additional water treatment. If this is the case, determine the unit or combination of units best suited for your water needs.
What Is The Best Reverse Osmosis System To Purchase?
There are many different brands of reverse osmosis systems to purchase. It is important to buy one that is high quality and also includes a carbon filter to block dangerous chemicals like pesticides, herbicides, and chlorine which are small enough to pass through the reverse osmosis filter. At WaterSmart we sell, install and service Duro Reverse Osmosis systems. These high quality systems come with both a pre and a post carbon filter. Click here to learn more about our high quality Duro system.
"I chose to go with Watersmart Systems. Best equipment, price, warranty and people!!"
R/O units are rated according to the amount of treated water produced per day. For example, one type of unit produces 50 litres of treated water per day under its design conditions. Such a unit is generally rated with 60 psi water line pressure, a water temperature of 25° C (77° F), normal dissolved solids and 2 atmospheres of pressure. In reality, conditions frequently vary. Line pressure is often lower, water will frequently be colder than 25° C and backpressure in the storage tank will likely reduce the performance of the unit. Consequently, you should examine water conditions and buy a larger rated unit than needed if any of the above problems are noted.
How Much Do Reverse Osmosis Units Cost?
Reverse osmosis unit prices vary, from $400 for a portable or undersink unit to $2,500 for a larger, stationary (basement) unit where a booster pump and a pressure system are installed. Replacement pre-filters range in price from approximately $50 – $200.
What Are the Benefits of Reverse Osmosis?
There are many benefits to using a Reverse Osmosis system. These include:
Remove Unwanted Substances: Reverse osmosis can remove dissolved solids, salts, minerals that cause hardness, organic chemicals and other impurities.
Improve Your Water's Taste: It can improve the taste of water for people who do not like the taste of dissolved mineral solids.
Protect Your Appliances: Treated water will not produce scale in kettles and coffee makers.
Helpful If You Need To Lower Your Sodium or Potassium: Because sodium and potassium are removed, people on a medically prescribed sodium- or potassium-restricted diet may benefit.
Remove Contaminants: R/O units may also remove contaminants such as chromium, mercury and nitrates.
What Does Reverse Osmosis Remove from Water?
Before purchasing a R/O unit, check the certification and literature for the particular model to verify exactly what it can and cannot remove. Reverse Osmosis Systems can remove common chemical contaminants such as:
They may also reduce:
Reverse Osmosis Systems have a very high effectiveness in removing:
protozoa (i.e. cryptosporidium, Giardia)
bacteria (i.e.Campylobacter, Salmonella, Shigella, E. coli)
viruses (i.e. Enteric, Hepatitis A, Norovirus, Rotavirus)
Is Reverse Osmosis - Treated Water Safe to Drink?
Reverse osmosis treatment systems remove minerals like calcium and magnesium from drinking water. In Canada, water is a minor source of such minerals when compared to foods. If you consume a reasonably balanced diet, you do not need to take a mineral supplement when drinking water treated with a reverse osmosis system. Low levels of minerals in drinking water may be a concern for people living in countries with very hot climates.
Is Reverse Osmosis Used In Bottled Water?
The majority of the bottled water companies use some form of filtration. It may be done by ion exchange, demineralization, reverse osmosis, distillation, deionization or any combination of these.
What Is Desalination By Reverse Osmosis?
Reverse Osmosis can also be used to desalinate salt water. In the same way that unwanted minerals and pollutants are removed from the water during the R/O process, so are the dissolved salts, making the resulting water fresh.
Why Purchase Your Reverse Osmosis System From WaterSmart
Why should you purchase your reverse osmosis system from WaterSmart? Price and Expertise. At large department stores, 70% of the product cost goes into marketing and the supply chain; door-to-door sales receive large commission fees. At WaterSmart we specialize in water products. We have over two decades of experience and expertise and are able to answer all of your questions. We can discuss with you your specific situation and help advise you about what you need.