With reference to bio-toilets used by the Indian Railways, consider the following statements:
- 1.The decomposition of human waste in the bio-toilets is initiated by a fungal inoculum.
- 2.Ammonia and water vapour are the only end products in this decomposition which are released into the atmosphere.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (d) Neither 1 nor 2
Neither statement is correct. Railway bio-toilets work by anaerobic digestion. A colony of anaerobic bacteria, not a fungus, breaks down the waste, which ends up mainly as water and biogas made up chiefly of methane and carbon dioxide.
- ✗ 1. The IR-DRDO bio-digester tank is charged with anaerobic bacteria to degrade human waste. The inoculum is bacterial, not fungal.
- ✗ 2. The bacteria convert the waste mainly into water and bio-gases, chiefly methane (CH4) and carbon dioxide (CO2), and these gases escape into the atmosphere. So the products released are not 'only' ammonia and water vapour, and ammonia is not among the named end products.
Remember · Railway (IR-DRDO) bio-toilets use anaerobic bacteria. Human waste is converted mainly into water and biogas (methane and CO2), not into ammonia and water vapour.
Sources
- PIB, Ministry of Railways – Bio Toilet Project in Indian Railways (2 Dec 2016) ↗ “acted upon by a colony of anaerobic bacteria that convert human waste mainly into water and bio-gases (mainly Methane CH4 & Carbon Dioxide CO2). The gases escape into the atmosphere”
- Indian Railways (RDSO) – Pamphlet on IR-DRDO Bio-toilet System ↗ “Anaerobic bacteria is added in the tank for degrading human waste.”
Question: UPSC Civil Services (Preliminary) 2015, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·
