Did you know that more than one billion people have no access to an improved water source? According to the World Health Organization (WHO), two million diarrhoeal deaths are related to unsafe water, hygiene, and sanitation, and sadly, the vast majority of which are children under the age of five. We always hate to read statistics like this. Wouldn’t it be great if there was a way to take contaminated water and make it drinkable? Well, actually, there is. It’s called reverse osmosis.
That’s a great question. Reverse osmosis may sound scientific, but in truth…well, it really is. First used as a method of desalinating (removing salt from) water, reverse osmosis is a process used to remove contaminants from water. It is commonly used today in water treatment centers, water recycling centers, and home water filtration systems. First, however, it might be better to understand osmosis.
Osmosis is the movement of a lower concentration solution through a membrane to a higher concentration solution. As clear as mud, right? Well, it really makes sense once you think about it. For example, say there is a concentration of tap water separated by a semi-permeable membrane from a solution of tap water and sugar. The lower concentration tap water will cross over the membrane to make the solution water more equal. That is osmosis.
Just as the name suggests, with reverse osmosis, the process of osmosis is reversed. In reverse osmosis, a higher concentration solution moves through a membrane to a lower concentration solution. This is how saltwater is desalinated. This is how it works…
Saltwater, which is water with a high concentration of salt, moves across a semi-permeable membrane that has microscopic holes small enough for a molecule of water to pass through but too small for anything larger. This leaves only pure water on the other side.
Reverse osmosis does not occur naturally, however; it requires high water pressure to force water through the membrane. Reverse osmosis provides high results for providing clean, pure water, which is why this process is used for many water treatment and recycling centers.
Reverse osmosis is not just used in commercial facilities, however. It can also be used in home filtration systems, and that might not be a bad idea. Much of the water coming into our homes is unclean and sometimes even unhealthy. Having a water filtration system is not a bad idea, especially if your household has small children or people with weak immune systems.
So what does a reverse osmosis home water filtration system entail? Well, a little bit more goes into the process than just forcing water across a membrane. This is how it would work if you installed a reverse osmosis system in your home today…
First, of course you need water, but that’s easy; it comes through the cold water supply. It first passes through a pre filter. Pre filters trap large contaminants such as rust, sediment, and sand; this protects the membrane from damage. The water then is forced through the semi-permeable membrane, which traps nearly all contaminants in water, including chemicals, odors, tastes, dissolved solids, suspended matter, etc. Reverse osmosis can even remove radiation particles. After it passes through the membrane, the water the goes through a post filter, which traps any contaminants left in the water, before it is sent to a storage tank.
Some systems even have a third “polishing” filter that filters the water once more before it exits the tank to be used in the home. Despite a few other components (valves, flushing, clamps, etc.), that is the basis of reverse osmosis.
What are some advantages of reverse osmosis as a home water filtration system? Obviously, the biggest advantage is that it removes harmful contaminants from your water. Though most city and well water is relatively healthy to drink, there are still impurities present in the water, and some water contains contaminants like chemicals, cysts, hard minerals, and other impurities that can be harmful to your health when consumed in large amounts. For this reason, having a reverse osmosis system is a good idea for having clean, pure water.
Miniature reverse osmosis systems are great for camping or hiking trips when you may be encountering contaminated water along the trail. No matter where you stay or what stream you pass, you can always have pure drinking water if you have your reverse osmosis filtration system. They can be used for virtually any water. In fact, they are so efficient, that some waste water management centers use reverse osmosis to turn waste water into drinking water. Inspiring thought…isn’t it?
On a large scale, reverse osmosis systems can indeed remove salt from saltwater, converting useless water into drinking water. This makes fresh water possible for ocean voyages and gives hope for a solution to limited supply of drinking water. However, as with everything in the world, nothing is perfect, and reverse osmosis has its shortcomings, as well, which leads to the disadvantages of reverse osmosis…
So if reverse osmosis is so great, why aren’t Third World countries using them to cure the problem of contaminated water? That leads to the number one disadvantage of reverse osmosis systems. They are very costly, especially for large scale use. Reverse osmosis systems are very expensive to operate. Even for a simple household system, the costs can be very high, ranging from $300-$3000, and replacements for membranes and filters are frequent and costly.
Another problem associated with reverse osmosis is waste. Reverse osmosis systems use only about 5-15% of the water coming through the system, and the rest is discarded as waste. This puts extra pressure on your septic tank, and it can cause a major problem for large scale systems. What is done with all the wastewater—which includes chemicals, salt, minerals, and other contaminants—left over after the useable water is collected? It is a problem that is still being debated.
Well, that answer is entirely up to you. Reverse osmosis definitely has both advantages and disadvantages, but those can be weighed to determine what is the best solution for you and your family. Many people install a reverse osmosis system just for drinking and cooking purposes, which cuts down on the amount of waste water. Also, the types of contaminants in your water have an impact on your decision. If you are considering installing a reverse osmosis system, then you should contact a water filtration system expert, weigh your different options, and find the best system for you, whatever it may be.