Zimba', a product that uses no moving parts or electricity, has been demonstrated to help chlorinate water in the simplest way. The product is now ready for commercial production

Huned Contractor

Chlorinating water is nothing new. It was first tried over 200 years ago and is today used extensively throughout America and Europe. However, the cost of the infrastructure required is prohibitively high for economically poor areas. And this precisely is what set Kolkata-based inventor Suprio Das thinking, and on the way to devising an absolutely low-cost and simple water purifier which he has named 'Zimba'. It is also the name of an international and multidisciplinary group aiming to improve access to safe drinking water. "The task we have undertaken - to produce a device that adds chlorine to water safely, accurately and economically - originated from D-Lab at the Massachusetts Institute of Technology. We are now working on a sustainable future for our proven technology," says Das during his participation in an exhibition for innovators in Pune.

Zimba leverages the principle of an automatic siphon to add a fixed amount of chlorine per batch of water that is pumped in. "From the beginning of the project, durability was known to be a key feature required. Moving parts such as hinges and gears are known to be the first point of failure in most designs. So from the outset, we strived to design a product with no moving parts. Electricity is expensive, unreliable or not available in many rural locations. Batteries too are not always available so we knew a design that didn't require a circuit board would have a greater range of applications and wider appeal. Gravity and the force it exerts on water is all that is needed to power a Zimba mixer," Das explains.

Also, while many are familiar with turning a tap to get water at a steady rate and constant pressure, Das and his team understood that it would not always be available. "As such, we worked hard to ensure that our design could deal with any method of input, be it from a tap, from a hand pump or poured in batches. And no matter what input you chose, our mixer delivers the same precision every time," he points out. One of the big benefits of adding chlorine to drinking water is continued protection against bacteria and germs. This is known as the chlorine residual and means you can keep water safely for longer and still be sure you are drinking clean water. "The ratio of water to chlorine required in drinking water is so fine that it is measured in parts per million. This causes problems for most people working with chlorine. Zimba, however, does work within the sensitive parameters and does it consistently," he says.

Das, a BIT Mesra alumnus (class of 1981) and former senior manager with Nicco Corporation Limited quit his lucrative job in 2002 to invent low-cost technologies for the poor. His first innovation in 2006, code named 'Firefly', was a unique battery that fitted on the wheels of a cycle-rickshaw that could be charged while the rickshaw puller went about his daily job. At the end of the day, he came back home with light and energy to his household. The charged battery could be attached to an ingenious LED light that would illuminate a room. After that he worked on producing electricity from water pumps, bicycle-powered cellphone charger (which was used by Sunderbans' residents when the cyclone Aila struck in 2009), and then Zimba.

"I have been working on the Zimba doser since 2010 and have been aided by a team of four international students at Berkley and MIT," Das informs. The Zimba team was one of the 30 semi-finalists in the MIT USD 100K Entrepreneurship Competition. A working prototype of Zimba was ready by 2011. Later, Zimba was successfully demonstrated at Stanford University, Cornell University and industrial summits in Dhaka, Ghana, and Sudan. To test the on-field utility, a pilot study was done in Sunderbans, West Bengal where five to seven hand-pumps were fitted with Zimba. While the water quality increased, the financial aspects were also encouraging. As of today Das is working with an entrepreneur who is also a hand pump mechanic for installing Zimba and charging a sum to cover costs. He has also been approached by various national and international business houses for commercial production of Zimba.

Speaking about the concepts that drove the creation of Zimba, Das says that the first objective was to address the need for pure water in many parts of the country, especially given the fact that every minute a child dies of waterborne diseases. Secondly, the priority was to keep the cost absolutely low so that it would be affordable in the poorest of areas. "With no moving parts, the maintenance cost is almost negligible. The only thing Zimba needs is regular chlorine replenishment but the cost of water chlorination is only Rs 5-10 per 10,000 litres, which is very affordable considering the cost of medication for waterborne diseases and associated severe repercussions," he states.

Born in a middle-class family in Shillong, Das has always been very sensitive to the problems in obtaining clean drinking water. He has worked with several NGOs like Aqua Welfare Society, GOAL India and Shipping Health to make safe drinking water available. Shipping Health has performed research on arsenic content in water and ways to reduce, if not completely eliminate, the level of arsenic in water. "Educating the masses regarding water purification is one aspect but more importantly making resources available to them is an uphill task. We are now hoping that the commercial production of Zimba will prove to be a step in the right direction," he says.

Contact Details:

Suprio Das, P-2, Block B, Lake Town, Kolkata - 700 089. Tel.: 09830582422. E-mail: firefly.power@yahoo.com.