Sphere No.44 (Mar 2018)

Technology focus Sphere #44 2018 20 ustralians love the sun and surf. Being on and in the water is second nature, from toddlers on surfboards to a plethora of world champion swimmers. When they aren’t in the ocean, they are in their pools. Just as central to family and community life as the barbie (barbecue), the pool is where Australians gather. It’s no surprise then, that they are also the world leaders in making the pool swimming experience even better through clever innovation. Their biggest water quality innovation often surprises visitors to Australia when they see the great swimming nation has ‘saltwater pools’. Especially if located close to the ocean, tourists could be forgiven for thinking that saltwater-chlorinated pools would taste like salty seawater. But in fact, Australia is a world leader in a water purification method that uses a far more human-friendly and environmentally friendly form of cleaning water – using salt to create chlorination. A SaltY]SOLUTION Salt never tasted so sweet Australians have taken the sting out of the pool swimming experience by using a high-tech solution. There is a better way Chlorine is the bane and boon of swimmers everywhere in the world. The smell of chlorine assures one that, assuming proper management, their environment is going to be clean, no matter how many people have been in the water. But the stinging of the eyes and the deadening of hair and skin caused by chlorine is detested. Frequent and competitive swimmers who use public pools endlessly discuss what products to use to avoid straw-like hair and how to get the persistent stink out, even after showering. The answer, surprisingly, is salt. While it is true that salt (NaCl) is the simple combination of sodium and chloride ions, its composition and how it is deployed can make a huge difference in, for example, how it impacts taste and cooking. But for those wise in the ways of salt, this simple chemical has a wide array of uses. Cheetham Salt, headquartered in Melbourne, knows its salt – it’s been producing it, with the help of sun, sea and wind-driven evaporation, since 1888. Cheetham Salt joined the CK Life Sciences Int’l., (Holdings) Inc. family of companies in 2013 and provides salt for a range of uses, from consumer products for the kitchen to industrial and pharmaceutical production. But it is salt used to chlorinate backyard swimming pools where the distinctly Australian flavour comes in. Or rather, it doesn’t. The secret of salt-chlorinated pools is that you can’t taste the salt. Nothing fishy about saltwater pools Again, tourists invited to a private swimming pool billed as saltwater chlorinated may be disappointed not to see toothy fish or even toothier saltwater crocs. But those immersed in a salt-chlorinated pool first notice what they don’t taste or smell – chlorine and salt. The level of salt is only 3,000 parts per million, well below the normal ocean salinity of 35,000 parts per million and even below the human tasting threshold of 3,500 parts per million. Almost 75 per cent of Australian households with private backyard pools have installed salt-chlorination systems.