Gone are the days when people drink from the tap. Nowadays, it is common to find bottled purified drinking water. One of the common ways of water purification is reverse osmosis (RO).
Reverse osmosis (RO) is a filtration method designed to remove many types of ions and large molecules from water solutions. In reverse osmosis, a pressure is applied to a solution on one side of the membrane. As a result, the solute will remain on the pressurized side while the purified solvent passes to the other side of the membrane.
Reverse Osmosis for Water Purification
The most common application of reverse osmosis is in purifying seawater to drinking water. RO can remove about 95 to 99 percent of salt and large particles from water molecules, making it safe to drink. The amount pressure required depends on the salt concentration of the water. The more concentrated the saltwater is, the more pressure is needed to purify it.
There are two important factors that affect the efficiency of reverse osmosis: the water pressure that comes into the system and the water temperature. The optimal pressure is 60-65 PSI while the optimal temperature is 77 degrees.
Stages of Reverse Osmosis (RO) System
The most common RO systems have 3 stages and 5 stages. The 3-stage reverse osmosis is commonly used for purifying running water in places that have saline water. Saline water affects the growth of plants so farmers install large-scale 3-stage reverse osmosis systems to provide pure water. Aquarium owners also use this type of RO system to provide chemical-free water that can support aquatic life.
A 4- or 5-stage reverse osmosis system, on the other hand, is most preferred for home use. It produces highly purified water that people can use for drinking, cooking and other purposes.
Stage 1 – Sediment Pre-Filtering
The pre-filtration process is meant to protect the membrane from clogging due to excess sediments. This stage focuses on reducing and removing large sediments and dissolved solids.
In case the water you are purifying is too hard or is one that contains 10 grains per gallon, it is recommended to start using other methods of water treatment before using reverse osmosis. That is why some people usually install a water softener to work side-by-side with their RO system.
Stage 2 – Activated Carbon Pre-Filtering
This pre-filtering stage is designed to remove oils and chlorine from the water as they are the most common causes of clogging in the membrane. This process also increases flow rate.
Stage 3 – Passage through the RO Membrane
The membrane has very tiny pores that filter water in a molecular level, allowing only hydrogen and oxygen molecules to pass through under pressure. Chlorine, sodium, calcium and larger molecules such as viruses and bacteria cannot pass. The dissolved solids and other contaminants that cannot pass through the membrane are then flushed out of the system.
The more pressure is applied, the faster will be the flow rate of the water. Since tap water does not have high pressure, a pressurized tank is usually a part of the RO system. Having a Best Reverse Osmosis System Reviews – Ro Water Filters Compared! can help you keep your family healthy.
Stage 4 – Post Filtration
The water that comes out of the RO membrane is already good for drinking. However, most RO systems use a storage device that is made of rubber to deliver a higher flow rate. The water that passes the storage device can have a rubbery taste and smell. To address this problem, many RO systems also include another filter after the storage device to ensure that the water quality is good.
Stage 5 – Reintroduction of Some Minerals
The last state is not really a filtration stage but a process in which some of the essential minerals that have been filtered out in the first four stages are reintroduced or added back. These minerals include magnesium and calcium as they are beneficial to our health. More advanced RO systems offer this feature.
Importance of RO System
Many people already install a water softener in their homes. Soft water is great for showering, laundry and cleaning. But would you drink soft water from the tap?
Many people would rather not drink soft water as it may still contain dissolved solids and other contaminants that a water softener is not designed to filter.
The water that comes out of the RO system is ideal for drinking. A reverse osmosis system is designed to remove sodium, dissolved solids and other contaminants in the water that can harm your health. Having a water softener and an RO system is a good combination for homes.
Reverse osmosis systems are typically installed in basements or under kitchen sinks. If you have a reverse osmosis system, you can drink healthy and clean water right from your kitchen sink.