Current Scenario of Drinking Water (Need of water purifiers)
The quality of drinking water is deteriorating daily. It is no longer as pure as it was during our forefathers time. Primary reasons why tap water may no longer be safe for human consumption are:
The impurities present in drinking water can be classified into
These are the physical impurities which remain suspended in water such as sand, dust, dead insects and harmful micro-organisms like bacteria, viruses and cyst. They lead to discoloration of water and may also cause diseases.
These are the chemical impurities which get dissolved and mixed with water. They cannot be removed by simple filtration techniques and require advance technology for removal. These impurities include chemicals, rust, pesticides, insecticides and salts of metals like arsenic, fluoride, iron, calcium etc.
Hence, with the constant deterioration in the quality of water and rise in impurities, it is now imperative to have a water purifier in our kitchens, irrespective of the source of water supply.
Presently available Water Purification Technologies
As the problems of impurities in water are increasing, thankfully so are the solutions to get rid of them. There are many technologies available in the market which can make contaminated water safe for drinking. However, each of these technologies has its inherent advantages and disadvantages. Some are simple and cost-effective, while some are state-of-the-art but expensive.
This is the most common and widespread form of purification technology available to us. Boiling effectively kills all harmful micro-organisms but has no effect on other suspended impurities like dust, sand, etc. It is also not able to remove dissolved impurities present in the water. The logic being simple- if you boil water containing sugar or salt, the water will still remain sweet or salty.
Boiling water is used as a method of making it potable by killing microbes that may be present. The sensitivity of different micro-organisms to heat varies, but if water is held at 70 °C (158 °F) for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. Clostridium spores can survive this treatment, but as the infection caused by this microbe is not water-borne, this is not a problem.
Ultra Violet (UV) Disinfection has been in the market for many years now. Some people also refer to this technology as electronic boiling. This technology successfully deactivates harmful micro-organisms like bacteria and viruses but fails to properly deactivate the more harmful ones – cysts. Also, if the water purified through this technology is stored for a long time, then there are chances that the deactivated micro-organisms may reactivate again.
When used in combination with other filters (sediment and carbon), this technology is quite effective in removing all suspended impurities as well as some of the dissolved gases in water. But similar to Boiling, this technology has no effect on dissolved impurities such as rust, arsenic, fluoride, etc.
RO technology is probably the best known purification technology to the mankind. It effectively removes all harmful micro-organisms such as bacteria, viruses and cyst. When it is used in combination with other filters (sediment and carbon), it successfully removes all other suspended impurities from water including dissolved gases and organic impurities. The biggest advantage of this technology is that it is able to remove more than 99% of dissolved impuritiessuch as chemicals, rusts, salts of heavy metals, pesticides andinsecticides present in water. Infact, RO is the only affordable technology to be able to remove dissolved impurities from water.
However, RO technology has its inherent disadvantages also:
The process is so efficient that all the dissolved salts (minerals) from the drinking water are filtered out including the essential ones necessary for our body. Water purified through only RO technology is distilled, has a bitter taste (because of no essential minerals) and has pH value lower than 7 which makes it slightly acidic.
Further, RO technology uses a very fine membrane which has a pore size of 0.0001 micron. The process requires raw water to be forced at a very high pressure so that water passes through the small pores of the membrane, which blocks the bacteria, germs and other impurities from passing through. However due to variation in day and night temperatures and high speed pressure, some of the pores of the membrane get enlarged after few months of continuous use, allowing harmful micro-organisms to easily pass through it, thereby making the process ineffective in the long run.