Date:26/10/2007 URL: http://www.thehindu.com/2007/10/26/stories/2007102659450700.htm

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Karnataka - Bangalore

Premier institute on conservation drive

Divya Gandhi

‘We plan to reduce our dependence on treated water from BWSSB’

— Photo: V. Sreenivasa Murthy

Trendsetter: The membrane bio-reactor waste water recycling plant in Cubbon Park, Bangalore.

BANGALORE: Everything from GIS mapping to membrane technology is what the Indian Institute of Science is planning to employ in its bid to save up to half a million litres of water every day and Rs. 1.1 crore on water bills annually.

“The water consumption in the campus, including that for residential areas, laboratories and garden maintenance on the campus is approximately 4 million litres a day (MLD),” said P.P. Majumdar, chairman, Department of Civil Engineering, IISc.

“We plan to reduce our dependence on treated water from Bangalore Water Supply and Sewerage Board for purposes such as gardening, by adopting three water conservation strategies,” he added.

These include recharging groundwater through rainwater harvesting; treating and recycling water on the campus with the help of membrane technology; and updating the 50-year-old water distribution systems, Dr. Majumdar said.

The most expensive component of the Rs. 3.5-crore project is likely to be the state-of-the-art submerged membrane bio-reactor to purify domestic sewage water, a technology that IISc plans to acquire in two years.

“Here, water passes through several layers of nano-membranes and a bacterial process purifies the water. While this may be more expensive than conventional sewage treatment plants, we found this one to be more effective, reliable and less space-consuming,” said M. Sekhar, Assistant Professor, Department of Civil Engineering.

This new technology is also “highly scaleable,” in that its capacity to treat water can be constantly increased.

The centralised recycling unit, to be built in the northern part of the campus (its lowest gradient), will generate up to 0.25 MLD of water, enough to meet the water requirements of the 15 acres of gardens within the campus.

When this is installed, it will be the second such bio-reactor to be brought into the city after the one installed by Bangalore Development Authority in Cubbon Park three years ago, he said.

While the water recharging and recycling systems could come into place by 2009, changing the old water distribution systems will take far longer, anything up to 10 years. “We will shortly be installing meters across the campus to conduct a water audit, to see how much water is consumed by various users. This information will be placed on a GIS system to establish where the points of damage to the distribution system are, to identify old or corroded components,” Dr. Majumdar said.