20/06/2015
Solar for water purification..
Meet Dr. Anil Rajvanshi, an Indian scientist who invented the path-breaking technology that can provide clean drinking water to rural India for just Rs. 1500!
Dr. Anil Rajvanshi brought back the traditional methods of filtering water in an effective and simple way to make a low-cost solar water purifier, which could be immensely helpful for rural households. Using the knowledge that water does not need to be boiled to make it germ free, and even exposure to a lower temperature for a sufficiently long time should suffice, he has created a low cost solar water purifier using cotton cloth, glass pipes and sunlight!
The water purifier is made available by Nimbkar Agricultural Research Institute (NARI), a Phaltan, Maharashtra based NGO.
“In most other solar heaters available in the market, water only gets heated up, it is not purified. And in other systems like RO, etc, water only gets filtered but complete sterilization is still lacking. So we came up with an idea where we can both filter the water and kill germs by heating it at a low cost using solar energy,” says Dr. Rajvanshi.
How does the technology work?
All you need is a discarded saree, a few glass pipes and sunlight. The solar water purifier (SWP) consists of four tubular solar water heaters attached to a manifold. The unclean water, which is filtered by the cotton cloth, is filled in the SWP and is later heated using solar energy to make it potable.
The unclean water is filtered through four-layered cotton sari cloth and then heated to 60°C for 15 minutes or 45°C for 3 hours so that all the coliforms are inactivated.
How is it different?
Other technologies, like reverse osmosis (RO) and ultraviolet (UV) based water purifiers, include filters which face clogging and necessitate their periodic replacement, and face other problems like wastage of water and unavailability of electricity in rural areas.
NARI’s SWP does not require any electricity and can be assembled easily from locally available materials.
The impact
The biggest impact of the technology is the development of a low-cost model, the know-how for which is made available for free by NARI Phaltan.
“We have not patented this technology so that the rural population can utilize it in an efficient way,” says Dr. Rajvanshi.
In addition to its low cost, the technology does not require any maintenance. It is so user-friendly and efficient that people from Nepal, during the recent earthquake, contacted NARI and asked them to install it there.
In the future, NARI team wants to expand the technology and reach out to more rural households.
When diseases caused by unclean drinking water take the lives of approximately 760,000 young children throughout the world¹, this low cost technology can prove to be a gamechanger.
Read more on http://bit.ly/1FqL8vF
