We all know that living creatures, including us, cannot survive without water. Yet, ironically life has evolved in a planet where most of the water present cannot actually be used directly, and the water that can be used is increasingly being polluted by industry and agriculture. Unfortunately, that leaves almost half the world’s population without clean, pure water.
To solve this problem, the United Nations have set a goal of doubling the number of people with constant access to potable clean water by 2015. It is estimated that this measure could save over 1 million people per year, mostly children. Many research teams are hard at work, trying to develop robust but effective ways of obtaining drinking water in less than optimal conditions.
One of these examples is the latest method using nanotechnology to solve this issue. The easy-to-use portable filtration device uses nanoparticles to eliminate not only dangerous heavy metals, but also bacterial contamination and other hazards.
Basically, the system involves two sequential filtrations and can produce over 10 litres of potable water per hour. In addition, it is an extremely cheap purification method, with associated costs for the equipment similar to other systems, but with the advantage of having running costs estimated to be less than £2 to operate for an entire year. This derives from the fact that it needs very little maintenance and filters are long-lasting, being able to clean up to 3,600 litres of contaminated water. Developers believe this device can comfortably cover the needs of an average family of four.
The system uses nanoparticles as a way to add anti-bacterial silver ions to contaminated water in the absence of electricity, while at the same time meeting internationally accepted values for concentration of silver in the final product. The filter uses a new material made up of small “cages” containing silver nanoparticles, and produces water suitable for cooking or drinking. The first filtration kills most bacteria and virus present in the water, followed by a second filtration to remove heavy metals, such as arsenic and lead.
As yet this filtering system is still a prototype, with the final version being currently developed. However, there are high hopes it could make a massive difference to people without access to drinking clean water.
Other uses for nanoparticles- desalinization?
Removing chemical and biological pollutants is not the only method to obtain clean water. In a process called desalinization, nanotechnology also shows some promise as an efficient and cost-effective procedure to remove salts from sea water.