What is Reverse Osmosis and How Does a Semipermeable Membrane Work

One very effective method used to eliminate contaminants and purify your family’s drinking water is a system known as reverse osmosis (RO). The technology behind reverse osmosis consists of a semipermeable membrane that removes larger particulates from drinking water. The membrane is designed to allow only certain molecules to pass through depending upon the molecule size, chemistry or solubility. Some membranes only allow molecules to pass through if they are bonded to another molecule. Testing your water is the first step in knowing what type of treatment you need for water contamination problems.


As more families are becoming health conscious and looking to improve their water supply, reverse osmosis systems have been gaining in popularity for their ability to efficiently and inexpensively provide pure, clean drinking water.


What Is A Reverse Osmosis Water Treatment System?


An RO system is designed to remove bacterial and fungal deposits that may contaminate water and render it unsafe. Reverse osmosis is one of the best types of treatment systems because it removes germs and contaminants from water making it safe for cooking and consumption.


Residential RO systems are relatively new and increasingly popular, but the reverse osmosis process itself is not new. Discovered in 1748 by Jean-Antoine Nollet, it has been popular in large-scale commercial applications to remove debris and dissolved solids from water. In the early years, there was no consideration made for removing smaller contaminants and RO was effective at slowing the death rate from water-borne diseases common at that time. In 1908 chlorination began and much improvement in RO performance was made. Chlorine was able to kill organisms that were invisible using technology of the time and were too small to be trapped by RO membranes.


Even though RO systems were effective at removing larger debris, the membranes could not remove contaminant with molecules smaller than water. This meant that when water was pressed through the membrane other smaller sized molecules had free passage, just like the water. This was when the technology changed to include other filtration stages.


The water is passed through a series of filtration stages designed to capture contaminants with smaller molecules as well as tiny microorganisms at different levels of filtration. If the first two stages were not able to capture all of the contaminants, later stages could effectively remove them. Some residential RO systems contain up to six filtration stages.


These six stages are not simply for purification. During reverse osmosis, certain beneficial minerals like calcium, potassium and magnesium are removed along with contaminants. These minerals are beneficial to good health, in fact, our bodies require them to work properly. Since the RO system removes them, they can be reintroduced back into the water later on during the filtration process to give you not only clean drinking water but also to preserve the nutrients needed by your body to function properly.


Types Of Residential RO Systems


Residential RO systems are available in different configurations. The most common are “point of use” systems that reside near your faucet. Some models are installed on the kitchen counter; others install under the sink. Each has benefits and drawbacks. Countertop models are relatively inexpensive, portable, and can travel to other locations in or outside of your home. Under the sink, models can produce greater quantities more quickly. If you have a large family, an under-sink RO system may make sense. If you're seeking an inexpensive solution, a portable RO system might be a perfect choice.


Overall, residential reverse osmosis systems are a great, affordable way to get a supply of fresh, clean and pure drinking water in your home anytime. Do your due diligence and speak with your water professional. The professionals at Skillings & Sons can help you make the best choice for your family’s unique needs.