The environment-friendly bio-toilets for passenger coaches were developed jointly by Indian Railways and Defence Research and Development Organisation (DRDO).In the bio-toilet fitted coaches, human waste is collected in bio digester tanks below the toilets and is decomposed by a consortium of anaerobic bacteria.By the process of hydrolysis, acetogenesis, acidogenesis and methanogenesis, the anaerobic bacteria converts human faecal matter into water and small amount of gases (including methane).
Indian railways aims to install human waste discharge free biotoilets in all its coaches and the same would be completed by September 2019.It will help in proving cleanliness and hygiene besides preventingcorrosion of the tracks.It is part of the Swachh Bharat Mission. Diagram of Bio -toilet:
