CMWSSB comes with Technology to convert Raw Sewage into Drinking Water on Southern Railway

CMWSSB comes with Technology to convert Raw Sewage into Drinking Water on Southern Railway

Chennai: Chennai Metro Water Supply and Sewerage Board (CMWSSB)  now has the technology to convert raw sewage into drinking water but the agency will be using the technology to help provide water to Southern Railways to clean the trains.

Known as Moving Bed Biofilm Reactor, this technology will be used for the first time in Chennai in the 10 MLD sewage treatment plant being constructed at Lang’s Road.

Interestingly, Chennai Metro Water is currently using Activated Sludge, a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoa. “This would reduce the organic waste in the water and final effluent will have 30 Biochemical Oxygen Demand (BOD). This is not good for consumption and the treated water is used for landscaping and other purposes,” a Metro water official said.

But in MBBR technology, the BOD can be reduced below 10 and if treated by ultra filtration method, the water can be converted into drinking water, the official said. But Chennai Metro Water is not going in for the ultra filtration method as people won’t agree to waste water being converted into drinking water, the official said. “We will be initially supplying 4 MLD of treated water to railways and this will be increased to 7 MLD of water,” the official said. Southern railways will be using the water for toilet, washing of trains and cleaning of station, he said.

The remaining 3 MLD of water from the STP will be provided to the Chennai River Restoration Trust for landscaping and gardening along the Cooum River.

Interestingly, the sewage treatment plant is being set up at a cost of Rs.13.86 crore. The MBBR technology is also a costly one. The official states that on a conventional way, the cost of treating 1MLD of water is Rs.90 lakh while MBBR costs Rs.140 lakh to treat 1 MLD of water. “We have floated global tenders for the project. The last date is April 21,” he said.