DRDO- MAHA-METRO to Implement Biodigester Mk-II Technology in Metro Rail

Defence Research and Development Organisation (DRDO) and Maharashtra Metro Rail Corporation (MAHA –METRO) have signed an agreement for water conservation and environment protection.  Under the agreement, MAHA –METRO will install biodigester units of DRDO in its facilities.

Key Points

  • DRDO Biodigester unit is a non-sewered sanitation technology.
  • The biodigester is an indigenously developed green and cost-effective technology. The technology also has a rare distinction of having one of the largest numbers of DRDO-licensees (ToT holders).
  • Under the agreement, DRDO will provide technical support for implementing its biodigester Mk-II technology for the treatment of human waste in the metro rail network.
  • As of now, about 2.40 lakh biodigesters have been installed by Indian Railways in its fleet of passenger coaches. Now under the Mou with MAHA-METRO, the technology has been improved and revamped to save water and space.
  • The up-gradation of the technology includes improvements in the design modification, bio-degradation efficiency, and addition of secondary treatment modules.
  • The new reactor is designed in a way to provide greater path length with increased time for biological reaction. This will enhance the system’s bio-degradation efficiency.
  • This Biodigester technology was initially developed for the armed forces in high altitude Himalayan areas, including Siachen glacier and Leh-Ladakh.


Maharashtra Metro Rail Corporation is a joint venture of the Indian government and the Maharashtra government. The corporation has the responsibility of all the metro projects in Maharashtra except the Mumbai Metropolitan Area. It is headquartered in Nagpur, Maharashtra.