Continuing its efforts towards conservation of environment, Maha Metro Nagpur has installed Bio-Digesters at its Metro Stations. This technology helps in recycling of used water for a multiple purposes. Use of recycled water ensures saving of water. The recycled water is used for multiple purposes.
Bio-Digesters have been installed at Khapri, New Airport and Airport South Metro Stations and are also being installed at other locations. Around 30 to 40 % or 800-900 litres of water are recycled at each station, thus saving on that quantity of water every day. Bio-digester is DRDO patented technology for sewage treatment.
Major highlight of this technology is fact that very less space is required for treatment; it doesn’t need electricity, thus saving on expenses otherwise incurred on power. Secondly, it doesn’t generate any sludge and hence doesn’t have any handling issues. Most important is fact that it attracts lesser capital investment compared to conventional engineering treatments such as Activated Sludge Process.
Additionally, it has better performance compared to septic tank treatment. In scientific terms, it consists of bio-digester tank and a specialized bacterial culture called Anaerobic Microbial Inoculum (AMI). Under controlled anaerobic conditions the specialized bacteria completely degrades the sewage into a gaseous by-product.
Maha Metro Nagpur has adopted above technology for achieving its environmental commitment of Zero Liquid Discharge. It is planned that sewage generated in operational phases would be treated using this technology. A MoU was executed between Defence Research and Development Organization (DRDO) and Maha Metro for transfer of this technology.
During the construction phase bio-digester treated sewage was only used for land discharge based end uses such as dust suppression. Presently it is being used for flushing purposes. The sewage which has been recycled after treatment has greatly reduced the fresh water demand. It is expected that on account of onsite sewage treatment units, Maha Metro shall reduce around 30 % of fresh water requirement.
The technology would gradually be used in other Metro locations such as stations and depots. Maha Metro has always contributed towards issues related to environment conservation. Installing bio-digesters is one of the major way by which Maha Metro has contributed towards these issues.