'Fly ash a cheap solution to Bellandur lake's pollution'

Several agencies may have come forward to clean Bellandur lake, Bengaluru’s biggest sewage-filled and highly polluted water body, at crores of rupees, but researchers at the CMR Institute of Technology here say they have a far simpler and cost-effective solution.

In a project report titled ‘A Universal Polluted Water Treatment System’, researcher Prof Phani Pullela said that executing the project would require just Rs 21.36 lakh.
How will it work?

Pollutants (organic, inorganic, heavy metals) bind to fly ash almost 100% at 50g/litre concentration in any kind of polluted water. “It (fly ash) helps in the treatment of polluted water even at 10,000/20,000 parts per million (ppm) sewage and industrial water,” Prof Pullela said. “The overall process cost is hydrogen peroxide and filtration set-up involving fly ash.”

According to Prof Pullela, water treated by fly ash is colourless and devoid of most pollutants, and fit for industrial and agricultural use. Once treated under ion exchange and reverse osmosis processes, the water can even be used for drinking.

In the second stage, Prof Pullela said, the proposal involves converting the pollutant-bound fly ash to bricks and using them for building drainage. “The polymer will lock the impurities in its solid structure. By this, the polymer coating will ensure that pollutants are locked inside the polymer—fly ash brick,” he said.

Prof Pullela has submitted the proposal to the Department of Biotechnology, Ministry of Science and Technology, Government of India, and is waiting for response.