"Membrane Bioreactors" are often discussed in the context of :
- (a) Assisted reproductive technologies
- (b) Drug delivery nanotechnologies
- (c) Vaccine production technologies
- (d) Wastewater treatment technologies ✓ UPSC's answer
Why the answer is (d)
• A membrane bioreactor (MBR) combines biological treatment of sewage by microorganisms (activated sludge) with membrane filtration (micro- or ultrafiltration) that replaces the conventional settling tank.
• The membranes retain biomass and remove suspended solids and pathogens, producing high-quality treated water suitable for reuse, in a compact footprint — hence MBRs are discussed in wastewater treatment, option (d).
• They are used in urban sewage plants, industrial effluent treatment and water-recycling projects, including several under India's Namami Gange and AMRUT programmes.
• Assisted reproduction, drug-delivery nanotechnology and vaccine production use other kinds of bioreactors or apparatus, not MBRs.
• Hence option (d).
Why the other options are wrong
- (a) Assisted reproductive technologies
- Assisted reproduction uses incubators and culture media, not MBRs.
- (b) Drug delivery nanotechnologies
- Drug-delivery nanotechnology does not involve membrane bioreactors.
- (c) Vaccine production technologies
- Vaccine production uses cell-culture bioreactors, not wastewater MBRs.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.