CHENNAI:Taking the ‘go green’ message forward, Chennai Metro Rail (CMRL) has set up an anaerobic sewage treatment plant at CMBT station recently.According to a press release from CMRL, anaerobic digestion is a collection of a process by which microorganisms break down biodegradable material in the absence of oxygen and is used for industrial or domestic sewage treatment.
As compared to the conventional aerobic treatment methods, the anaerobic process offers significant benefits like zero-energy consumption, minimal sludge production, minimum sludge production, minimum space requirement, lung nutrient requirement, low nutrient requirement, space saving, emission free and profitable.
The treated water meets Pollution Control Board (PCB) norms in water quality. At CMBT station, CMRL has constructed an anaerobic sewage treatment plant for 10KLC capacity and commissioned on June 5. CMBT is one of the metro stations with a large number of passenger footfall and a large amount of sewage generation. Water usage at CMBT station for toilets is around 6,000 litres per month. Since the sewage system of CMBT station is not connected to main sewage, sewage collected in the collection pit shall be removed at regular intervals. It was decided to have a sewage treatment system which will reduce the water consumption and avoid the cost of sewage removal. It was decided to have a sewage treatment system which will consume no power.
Now Rs 15,000 is saved on water purchase, and Rs 8,000 on sewage removal per month. The treated water is used for watering the garden available in CMBT station. There is also a plan to use treat water for toilet flushing by providing an ultra-filtration facility.