Humans have faced the challenge of water quality for thousands of years. Even as far back as the 4th and 5th centuries BC, Hippocrates, the father of modern medicine, linked impure water to disease and invented one of the earliest water filters. Known as the ‘Hippocratic sleeve’, this filter was a cloth bag through which water could be poured after being boiled and it would trap any sentiments in the water.
World Water Day, held on 22 March every year since 1993, celebrates water and raises awareness of the 2.2 billion people living without access to safe water.
Today, in India and around the world, millions are navigating the COVID-19 pandemic and many of them have the added challenge of living without access to safe water. Now more than ever, access to safe water is critical to the health of families around the world.
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The water crisis
As India grows and urbanises, her water bodies are getting more and more polluted. According to World Economic Forum (WEF), it is estimated that around 70% of surface water in India is unfit for consumption. Every day, almost 40 million litres of wastewater enters rivers and other water bodies with only a tiny fraction adequately treated.
The health costs relating to water pollution are alone estimated at about Rs 470-610 billion (US$ 6.7-8.7 billion per year) – most associated with diarrheal mortality and morbidity of children under five and other population morbidities. Apart from the economic cost, lack of water, sanitation and hygiene results in the loss of 400,000 lives per year in India. Globally, 1.5 million children under five die and 200 million days of work are lost each year as a result of water-related diseases.
While water purification technology has gone through many improvements in the recent past, Reverse Osmosis (RO) and Ultraviolet (UV) purifiers are the two most popular options in India for getting safe drinking water in our homes. Both come with their own pros and cons - One-size-fits-all formula doesn’t apply to water purifiers. First, you need to ascertain your family size, daily water consumption etc. You also need to measure your water’s TDS (Total Dissolved Solids) level, to take a decision on the type of water purifier required for your home. The more TDS your water will have, the more advanced water purifier you will require.
RO, UV or UF?
RO stands for Reverse Osmosis, a water purification technology that uses a semipermeable membrane to remove ions, molecules and larger particles from drinking water. It removes dissolved salts, large particles as well as most types of bacteria and germs. This is done by moving molecules from a region of high concentration to one of low concentration, using pressure to push water across the membrane, leaving the impurities behind in each stage. The RO system works effectively in removing high TDS.
Ultra Violet System (UV) is a water purification method that uses ultraviolet rays to perforate the harmful pathogens in your home’s water and kill the disease causing microorganisms by attacking their genetic core (DNA). An UV water purifier is enough if your water has a low TDS level. Since UV filters are unable to change the TDS, they are not recommended for well water. However, UV purifiers can still work well with lakes, rivers, and even municipal water supplies. Due to already low TDS levels, all the purifier needs is to eradicate microorganisms, making the water safer.
The difference between UV and Ultra Filtration (UF) is that UF technology works without any electricity. It eradicates suspended solids, larger particles, and molecules from water through a hollow membrane. However, this kind of water purifier does not get rid of the dissolved solids. Unlike the RO purifier, it also cannot convert hard water to soft water. Hence it is wise to use an RO UV Water Purifier, coupled with UF filtration, especially when you are not certain of the TDS levels in the water.
There are more than ten brands of water purifiers in the market- Tata Swach, Eureka Forbes, Kent, Pureit, etc. Each of these product differs in cost, type of filter they use and the method of purification. Most water purifiers today combine two/three techniques together. For instance, Eureka Forbes’ Aquaguard Protect Plus (click to buy) combines advantages of a RO purifier and UV sterilisation. Hindustan Unilever’s Pureit Marvella UV (click to buy) provides the benefit of UV sterilisation as well as offers filtration through an activated carbon filter.