TATA SWACH
Tata Chemicals unveiled their unique and innovative water purifier called 'Tata Swach' on 7th December, 2009. 'SWACH' means 'clean' in Hindi. The Swach does not require electricity nor piped water to work.
Tata Swach uses Rice Husk Ash impregnated with Nano Silver particles. Rice Husk Ash (RCA) is the filtering medium for water and the nano-silver particles kills bacteria, germs and other organisms. This filter also claims to meet the US EPA standards for germ kill of 6-log reduction of bacteria, 4-log reduction of viruses, and 3-log reduction of protozoan cysts. This filter also has an automatic Cut-off mechanism to prevent flow of water when its filtration capacity is finished. The Tata Swach water filter took the 2010 top Gold award prize in The Wall Street Journal's Asian Innovation Awards. Swach costs Rs.999-.
The Tata Swach water purifier uses Rice Husk Ash (RHA) impregnated with nano-silver particles as the water purifying media. Rice Husk Ash (RHA) contains activated silica and carbon, where the activated silica reduces the turbidity or cloudiness of the water entering the filter and the Activated Carbon adsorbs most of the toxic organic impurities.
This unique filter uses Nano technology, which means 'the science of matter on an atomic and molecular scale' or in simpler language 'the science of very small particles of matter of a size between 1 to 100 nanometers'. A Nanometer means 'one billionth of a Meter or equal to 10−9 of a meter' which is indeed very, very small, almost the size of an atom, the smallest particle of matter. To give some idea of the size of a Nanometer: "a nanometer is the amount an average man's beard grows in the time it takes him to raise the razor to his face"(quoted from Wikipedia).
Again to quote from Wikipedia "Materials reduced to the nanoscale can show different properties compared to what they exhibit on a macroscale, enabling unique applications. For instance, opaque substances become transparent (copper); stable materials turn combustible (aluminum); insoluble materials become soluble (gold). A material such as gold, which is chemically inert at normal scales, can serve as a potent chemical catalyst at nanoscales. Much of the fascination with nanotechnology stems from these quantum and surface phenomena that matter exhibits at the nanoscale."
Silver has been known to have preservative and antimicrobial properties from time immemorial. Hippocrates (460 BC – 370 BC), the ancient Greek physician considered as the "father of medicine", wrote that silver had beneficial healing and anti-disease properties. The ancient Phoenicians (1550 BC to 300 BC) are said to have stored water, wine, and vinegar in silver bottles to prevent spoiling. In the early 1900s, people would put silver coins in milk bottles to prolong the milk's freshness. Even now Silver compounds continue to be used in external antiseptics. Silver nitrate in dilute solution is still used as eye drops to prevent conjunctivitis in newborn babies.
The anti-microbial properties of Silver gets multiplied several times over at the nano-level, and it is this property that the Tata Swach takes advantage of in its filter, to give safe drinking water.
The Tata Swach water purifier costs Rs.999-