A hope for water

A shortage of water, especially during summers, is one of India’s biggest worries, with an even bigger problem adding to it — finding safe and affordable drinking water.

But working on plugging that leak is Dr S. Sridhar and his team of researchers at the Indian Institute of Chemical Technology (IICT) in Hyderabad, whose work in water filtration through advanced reverse osmosis techniques earned him the Hindustan Lever Biennial Award in his field of Chemical Engineering, by the Indian Institute of Chemical Engineers.

Dr Sridhar is the Principal Scientist for IICT’s Membrane Separations Group and has worked with the team ever since 1995, when he joined as a research associate, after gaining a Bachelor’s degree in Chemical Engineering from Osmania University in 1994. Later absorbed as a scientist into the institute, his life’s work is now being implemented in over 12 pilot plants across Telangana, Andhra Pradesh and Tamil Nadu.

His water purification systems work on membrane filtration, remineralisation and pressurised reverse osmosis techniques that allow 1,000 litres of pure drinking water to be generated per hour, at the cost of just 4 paise per litre (and a one-time investment of around Rs 3 lakhs) that’s safe from fluoride and arsenic, two of India’s biggest water pollutants. The pilot projects have a capacity of around 6,000 litres per hour.

“We’ve also now developed a very compact system which costs only about Rs 35,000 but gives about 150 litres of pure drinking water per hour,” says Dr. Sridhar, adding, “Because of its moderate capacity, it can be installed in schools, colleges, hostels and hospitals. It also works on a single phase power supply.”

The team has also developed nano-filtration and ultra-filtration techniques for water that has a plethora of uses, including generating medical-grade water. “We had put up the first nanofiltration membrane for effluent treatment back in 2006 in West Bengal for decolourisation of water. But then we found that the same membranes can be used for water filtration as well because it allows sufficient minerals to pass through while rejecting the excess hardness and impurities present in the water,” he says.

However, developing these membranes in India has been a challenge, with Dr Sridhar having to resort to some jugaad to make his systems work —  “For membranes for solvent dehydration or sodium azide removal, we either have to import membranes or find tailor made machines. So what we do is we import membranes from abroad but design and assemble our own stacks and modules.”

The scientist, who has earlier won several awards such as the Council of Scientific and Industrial Research’s Young Scientist Award in 2007, also lists crickets as another of his passions, having captained the IICT’s team for two years. And even though the IICT’s campus also make the most of the water that his systems produce through various plants on site, he says that his sole aim in working on the water filtration techniques is to help people in need. “In the beginning we had to put in a lot of work and we’re only reaping the fruits of our labour now. It’s a group effort rather than just me, so it’s everyone’s award,” he concludes.