Is it all grey?

  • 29/06/2003

Is it all grey? Every year Indian thermal power plants (TPPs) spew out 100 million tonnes of flyash, a grey outpour soon expected to reach 175 million tonnes. According to current estimates nearly one lakh hectares (ha) of land in India is taken up by ash ponds. Bad news for the environment. For, most of the flyash is disposed off in ash ponds, from where it contaminates both surface water and groundwater. As if that isn’t bad enough, exposure to flyash has been linked to diseases such as silicoses, fibrosis of the lungs, cancer and bronchitis.

Flyash is a byproduct of coal combustion. TPPs powered by this fossil fuel are the mainstay of India’s power sector. In 2002, out of a total of 1,04,917.50 megawatts (MW) of electricity generated in India, 74,428.82 (MW) was generated by TPPs alone. According to a report titled Clean Coal Initiatives by the New Delhi-based Central Pollution Control Board, 70 per cent of electricity generated by TPPs is through coal. Indian coal has high ash content (45 per cent); ergo, more flyash.

With coal expected to drive the power sector in India at least till 2012, flyash is a matter of grave concern. According to some experts, utilising flyash mitigates its harmful effects. Says K Basu, a former scientist with Bharat Heavy Electricals (BHEL), Hyderabad, “We have the technologies to increase flyash utilisation. What we need is to integrate the chain of coal consumption, flyash generation and flyash utilisation. Also we need policies to make flyash products more profitable.” But many question flyash usage on grounds of environmental safety. Flyash is an alumino silicate glass consisting of the oxides of silicon, aluminium, iron and calcium with minor amounts of magnesium, potassium, zinc, sulphur and other trace elements. These elements can leach into the environment, enter the food chain and affect human health.
Promoting flyash… In 1994, the government of India started the flyash mission (FAM)

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