The BBMP has set up two leachate treatment plants of nearly 1.50-lakh-litre capacity to dispose the black coloured liquid that is produced during the decomposition of waste. The plants were set up by the civic body and Karnataka Rural Infrastructure Development Ltd.
Civic officials claim that the plant at the Bellahalli quarry pit, which has a capacity of 1.20 lakh litres, is one of the biggest leachate treatment plants in the word.
The other, at the Doddabidarakallu processing unit, is of 25,000-litre capacity.
The leachate in other processing units is being taken to these two treatment plants by tankers. The two plants have been functioning on an experimental basis for the past three months.
“The leachate goes through a five-stage filtration process. The treated water is used in BBMP parks and let into stormwater drains,” said Sarfaraz Khan, Joint Commissioner (Solid Waste Management and Health), BBMP. "The treated water has been sent to the laboratory for testing. The BBMP is now contemplating setting up such leachate treatment plants in the other processing units too."
Every day, nearly 4,000 tonnes of waste generated in Bengaluru is taken to one of the seven processing plants or dumped in landfills. The leachate produced by the waste is toxic and could contaminate the groundwater and other water sources. Civic officials hope that the new plants will help address this problem.
From leachate to clean water
Stage 1
Raw leachate is pumped into a tank. It goes into a ‘boomtube resonator’, which converts the compounds / pollutants into elemental state by using a patented technique
Stage 2
Water from the boomtube has pollutants that are separated as suspended solids of very fine particles. This is sent to a collection tank where an equipment that creates turbulence is used to make fine particles bigger with a thickener.
Stage 3
The water is pumped to a plate settler, which settles the bigger particles. The bigger particles are removed as sludge and put on a sludge drying bed.
Stage 4
Through a filter feed pump, the water is pumped to a multi-stage dual media filter and specialised activated carbon filtration system.
Stage 5
It is then processed through a specialised industrial filtration system. The end result is clean, fresh water
