Delhi Jal Board sets up pilot plant to treat 4 million gallons of sewage water a day

As part of the process, the drain water is made to go through an electrocoagulation reactor, which removes iron sludge from the water. A chemical coagulant is added to it, which makes the solid pollutants settle at the bottom. The cleaner water from the surface is then skimmed and allowed to sit in a tank where oxygen supply is reduced to kill harmful bacteria. The water is then passed through activated carbon and multi-grade filters. Treating it with UV rays and reverse osmosis makes it fit for ground-water recharge and drinking purposes respectively.

“It takes Rs 45-50 to treat a kilolitre of water with this plant… the process is cheaper by 50 per cent than that done through conventional treatment plants. The total dissolved solids (TDS) in drain water is more than 400… With this process, we have brought it down to 70…,” said Bhattacharya.