Reverse Osmosis Water Treatment
Reverse Osmosis is a comprehensive water treatment method. It typically includes prefilters that protect the membrane by removing sediment and chlorine (which can damage thin RO membranes).
Then, they force water through a semipermeable membrane to remove unwanted contaminants. Reverse Osmosis systems then store the treated water in a pressurized storage tank and serve it through a dedicated faucet. Some systems have additional post-filtration stages that polish and remineralize the water, too.
What is Reverse Osmosis?
Reverse Osmosis is a highly effective method of water purification that is often used in industrial settings. It gets water clean to a molecular level by using a semi-permeable membrane that separates water molecules from other contaminants like salts, chemicals and bacteria. It is a great option for well water with difficult contaminants like nitrates, which are not easily removed by other types of home water filters.
This filtration technology is one of the most effective available, removing a wide variety of harmful contaminants from drinking water. But it is expensive to install Reverse Osmosis Water Treatment and maintain, and wastes around 3-20 gallons of water for every gallon that it produces. This makes it impractical for homeowners who already have potable tap water that is safe to drink.
The process works by applying pressure to overcome osmotic forces that favor even distributions of particles across a membrane. This pressure causes the dissolved salts and minerals to move from the stronger solution on one side of the membrane to the weaker solution on the other side of the membrane. The membrane is made of a thin film composite (TFC) or cellulose triacetate (CTA) membrane that is resistant to chlorine degradation, but it is still susceptible to bacterial attack. Therefore, a high-quality granular activated carbon pre-filter and/or post-filter should be added to the system to prevent contamination of the RO membrane.
How Does Reverse Osmosis Work?
Reverse osmosis removes contaminants and sediments from water down to the molecular level. It removes chloramines that irritate noses and eyes, hardness, which makes it impossible for soap to lather and leaves hair dull, and dissolved minerals that make water acidic.
Reverse Osmosis works by pushing water under pressure through a semi-permeable membrane. The membrane removes a majority of the dissolved contaminants from water. These contaminants can include chlorine, organics, bacteria and pyrogens.
The membrane rejects contaminants based on their size and ionic charge. Generally, the larger the contaminant, the less likely it is to pass through the membrane. The ionic charge of the contaminant also plays a role. Normally, water has a positive electrical charge. However, a negatively charged contaminant can be attracted to the negatively charged membrane and cling to it.
Water entering the RO system goes through prefiltration to protect the membrane. This prefiltration includes carbon and sediment filters that filter out debris that could clog or damage the membrane. Then the water passes through the membrane where dissolved particles, even those too small to see with an electron microscope, are removed.
After the filtration process, water is sent to a storage tank or drain. This produces bottled water quality hydration in your home, eliminating the need for bulky and wasteful cases of bottled water. The storage tank can be sized to suit your household’s water consumption.
How Much Water Can Reverse Osmosis Produce?
Reverse Osmosis is a great choice for areas with limited fresh water, or for desalinating ocean water. However, the process can produce a lot of waste water. To eliminate this, add a permeate pump to the system. This will reduce wastewater from the RO system by 75 to 80%. Make sure the RO system you purchase is plumbed for a permeate pump.
RO systems require a significant amount of pressure to push water through the membranes. This can range from 40 to 400 pounds-per-square-inch (psi). Brackish water reverse osmosis (BWRO) uses the same process as SWRO but with less salty feed water (think bays and estuaries).
In addition to high installation costs, most RO systems have a small capacity. This means that homeowners will need to store the filtered water in a pressurized storage tank. A typical under counter Reverse Osmosis tank holds 2 – 4 gallons and can be installed under the kitchen sink.
Most RO units have a prefilter to remove sediment and chlorine to protect the membranes. Additionally, water softeners can be added to prevent scale build-up and clogging of the membranes. Lastly, carbon post-filters can be included to improve taste and reduce odor. In some cases, a full-house reverse Filling Machine Supplier osmosis system is needed for whole house drinking water treatment. In these situations, other water quality issues must be addressed before the water gets to the RO membranes.
How Much Water Should I Drink?
A reverse osmosis system reduces many contaminants including fluoride, salt, chlorine, arsenic, herbicides, pesticides and more. It also removes dissolved solids, which makes it healthier than drinking water that has not been through an RO filtration process (unless you use a home distillation system).
The most important thing to remember is that even though RO filtered water is very pure, it is not completely free of contaminant residues. This is why a reverse osmosis system should always be followed by a postfilter to remove residual tastes or odors that could be present in the storage tank.
Reverse Osmosis can consume between 4 and 6 gallons of water per gallon of purified water it produces. This is based on the amount of contaminants in the water supply and on factors such as water temperature, membrane recovery ratio, system size, condition of filters and membrane, and the pressure at which the system operates.
A reverse osmosis system is a great option for families that want better-tasting, cleaner water without the worry of contaminants that are found in many municipal and private well water supplies and in some bottled waters as well. It’s important to note that while the EPA regulates tap water, it does not have as stringent regulations on bottled water. This is why you should consider a Kinetico Reverse Osmosis system for your home to guarantee the quality of the water you and your family drink.
