With every passing year we learn more about what is in our water and the effects those contaminants can have on our health. It takes the EPA years of study to figure out what is an acceptable level for contaminants in our water or how best to treat them. Contaminants in residential drinking water can include almost anything, from industrial waste that was dumped in a river, to fertilizers and household cleaning products. Many times, treatment involves adding a chemical to the water to neutralize the contaminant—for instance, chlorine is added to water to control the number of microbes—but these chemicals can give water undesirable tastes or odors. Technology like reverse osmosis systems exists to remove contaminants from water without adding any chemicals.
A reverse osmosis membrane uses a semi-permeable membrane to separate water molecules from other molecules. “Semi-permeable” means that some things can pass through and others can’t. A familiar example would be your furnace’s air filter, although, semi-permeable membranes for water treatment allow passage based on the size of the particle as well its molecular charge whereas typical air filters separate the contaminants exclusively by size. Holes or pores in the membrane are sized just big enough for the passage of a water molecule—even small contaminants such as tobacco smoke or paint pigments are too big to go through an RO membrane. At this point, because the membrane only lets certain molecules pass through, there is some waste liquid with a highly concentrated amount of contaminants that goes to the drain. The virtually contaminant-free water that makes it through the membrane, called a permeate stream, is safe to drink and tastes great.
Reverse osmosis technology relies on pressure to push the water molecules through the membrane. Water pressure varies with your water source. City water is usually supplied between 40 and 100 psi (pounds per square inch). Well water is usually less pressure, delivered between 20 and 60 psi depending on your pump. The production rate of the membrane is dependent on factors such as temperature, pressure and Total Dissolved Solids levels. Because flow and production rates vary, most RO systems also have a storage tank, allowing more pure drinking water to be available on-demand, so you can fill your glass or pitcher much faster.
Because the water is so pure, bad tastes and odors from the storage tank’s bladder and walls can find their way into the water during prolonged contact, so they must be taken out. That’s why a postfilter is an important part of the reverse osmosis system; any odors or tastes picked up from the storage tank are removed and the water is once again great-tasting.
If your home has questionable drinking water, maybe it’s time to invest in a reverse osmosis drinking water system—you won’t regret it. Kinetico offers multiple reverse osmosis systems like the K5 Drinking Water Station and the Aquakinetic A200 to fit all needs and budgets. Click below to get a quote or have a Kinetico Water Specialist come to your home and perform a water test.