The What, Why and How of RO Water Purification

 Using a water filter or a water purifier is a common scenario in many households, though the technology used could be different as that depends on the quality of water supply at home. The purification system could be anything like Ultrafiltration (UF), Reverse Osmosis (RO) or Ultraviolet (UV). It could also be a combination of two or three technologies. You can easily buy water filters online once you have decided on the right combination of purification technology for your needs. In this article, let us learn more about RO water purification technology.



 What Is Reverse Osmosis?

Water has the tendency to flow from a region of low salt concentration to that of high salt concentration. This process is called osmosis. In reverse osmosis, this process is reversed i.e. the high concentration solution is made to flow towards the lower concentration through a membrane with very fine pores. This membrane allows the water to pass through but the smallest of the dissolved impurities and bacteria get trapped and are unable to pass through and discarded as wastewater.

When Is Reverse Osmosis Used?

RO is required when the water supply of the locality has high TDS levels. This kind of water is generally underground water drawn from bore wells. The RO system removes the dissolved salts and harmful metals from the water, thereby making it fit for consumption. If the TDS levels in the water are low, you must not choose RO as your purification technology as it could end up pushing the TDS levels below the recommended lower limit.

The Mechanism of Reverse Osmosis Purification System

External pressure is applied to the water with the help of a pump with the intention of reversing the water flow. The water now gets pushed towards lower TDS through the semi-permeable membrane. Other than the pump, there are several other components in this system:

  • Sediment Pre-Filter: The first stage of the purification, sediment pre-filter removes all the dirt and insoluble impurities. It helps to improve the life of the RO and UF membrane, which makes up the next stage of filtration.
  • RO/UF Membrane:The water is transferred to this chamber using high pressure. It passes through the membrane leaving the soluble impurities such as salts, pesticides and heavy metals behind. The microbial components are also removed in the process. The RO membrane is also similar to the RO membrane but is not designed to remove soluble content.
  • Activated Carbon Filter:This helps in removing chlorine and other organic contaminants such as pesticides. This component also absorbs the compounds, which give the water a bad taste and odour.
  • TDS Controller:This component helps to maintain the required TDS level of the water. With RO, most of the salts get removed from the water. The TDS controller helps retain sufficient quantities of essential minerals. The water from the UF membrane and RO membrane are combined in an appropriate ratio to ensure that it has the essential TDS level.
  • Display:The display on most of the RO purifiers will include the on/off buttons and the tank water level indicator. Advanced models build in the TDS indicator, purity indicator and fault alarms as well.

Now that the entire process of RO has been explained, you will be able to understand the science that goes behind the purification process. This can also help you make a better choice of purification technology when buying water purifiers online.