JOIN USFirm offers to produce power, water from Bellandur's sewage
The Bellandur lake frothing shows no signs of abating. But the can state government, cornered by the courts and the National Green Tribunal (NGT), ignore alternatives, one of which promised conversion of the lake’s sewage to 5,000 MW of energy every day?
No amount of cosmetic solutions will work unless the underlying toxins are removed. How do you clean up the lake, when 45 crore litres of sewage end up in the city’s largest water body every day? The solution proposed by AG Dauters, the India partners of the American-German firm Langenburg was this: To separately process the three components of sewage: sludge, water and dissolved impurities.
Besides power, the process was to generate about 20 to 30 crore litres of water daily, and produce biodiesel as a byproduct. In a presentation to the government in March this year, the firm had offered to invest Rs 40,000 crore on the plant at zero cost to the state. In return, the government had to purchase the power, water and gas. However, the government is yet to take a final call.
Here’s how the process will work: The sludge and dissolved impurities extracted from sewage are subjected to a process called plasma gassification. This, as Ajay Girotra from AG Dauters explains, will convert waste to gas, which in turn will run the turbines to be installed as part of the project.
The extracted water is converted to hydrogen and oxygen in gaseous form before being reconverted to water. “This way, 20 to 30 crore litres of water can be generated daily. The city’s water shortage can be entirely addressed,” explained Girotra.
Although Bellandur lake has 13 inlets, four drains bring in the bulk of the sewage. Dauters proposed to build four treatment plants at the pit site of these canals entering the lake. “There will be no financial participation from the government. But the plant will need 2-3 acres of land at each pit site. About 50m X 50m of space.”
The infrastructure, according to Girotra, can be put in place in nine to 12 months. A power purchase agreement (PPA) and similar agreements for purchase of water and fuel will have to signed with the state departments.
Using the same technology, Girotra said, a sewage treatment plant is being built at Katol in Maharashtra. Another deal for a solid waste management plant was inked with the Punjab government.
The Karnataka government, said officials in the energy department, is awaiting a detailed project report from the firm. Only then can it be placed before the Cabinet for approval.