Water Purification – Science to the rescue!
Water purification in South Africa
Did you know that we are able to clean water through a variety of methods? This is great news because so many of our precious water sources have become undrinkable due to pollution. A water source might not have disease causing microbes living in it but it can still be undrinkable due to the high levels of certain chemicals.
In South Africa we have to make sure that our water is in line with the South African National Standard for Drinking Water (SANS 241) and the World Health Organisation (WHO) guidelines. This means that the water is safe to drink straight from the tap! These plants draw water directly from a source, like a dam, or they recycle water that has already been used.
Wisdom from our clubs!
“With the lack of purification
there are so many complications
I will save water now...”
-Science Photons (Emzamweni Science Club)
But what if your water source doesn’t pass through one of these purification systems?
Many South Africans live in rural areas, and rely on water found in rivers or boreholes. This sources are untreated and so may be contaminated with pollutants. Well this is where nanotechnology can help improve and even save lives! Nanotechnology is the practice of manipulating materials at a very tiny scale. How tiny? Well, the sizes of atoms and molecules are measured in nanometres (1nanometre = 1 billionth of a metre. In symbols, 1nm=10-9 m.) So nanotechnology works with materials so small that they cannot be seen with the human eye – not even through a light microscope! In South Africa, the National Nanotechnology Strategy (NNS) was launched in 2006. Water is one of six focus areas highlighted in the NNS where nanotechnology can offer the best benefits for South Africans!
One of the amazing ways of using nanotechnology is the ‘tea bag’ filter. A team at Stellenbosch University, headed by Prof Eugene Cloete developed the “tea bag” which can be placed in the neck of a bottle to kill disease-causing microbes as water passes through the filter, thus making the water safe to drink! The inside of the ‘tea bag’ is coated with a thin film of biocides (chemicals that kill microbes) encapsulated with nano-fibres (incredibly tiny ‘hairs’), so as the filter traps bacteria, they are killed by the biocide coating.
Are you fascinated by nanotechnology and how it is used to clean our water? For more information visit www.npep.co.za. Also look out for the next issue of Spaza Space where you can read about many more examples of scientists using nanotechnology to help make water safe to use!