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?
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2
- (d) Neither 1 nor 2 ✓ UPSC's answer
Why the answer is (d)
• Indian Railways' bio-toilets, developed with DRDO, use a consortium of anaerobic bacteria (not fungi) in a bio-digester tank to break down human waste — so statement 1 is wrong.
• The end products are mainly methane and carbon dioxide (vented) plus treated water, not ammonia and water vapour only — statement 2 is wrong.
• Hence neither 1 nor 2, option (d).
Why the other options are wrong
- (a) 1 only
- Statement 1 is wrong: bacteria, not fungi, are used.
- (b) 2 only
- Statement 2 is wrong: methane and CO2 are the gaseous products.
- (c) Both 1 and 2
- Both statements are wrong.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2015, held on 23 August 2015. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.