Deuterium (²H/D) from natural waters

Why in News?

• According to the Government of India report, H₂S–H₂O bi-thermal chemical exchange technology is used in India to extract Deuterium (²H/D) from natural waters at:
  • Manuguru, Bhadradri Kothagudem, Telangana (Godavari water).
  • Kota, Rajasthan (Rana Pratap Sagar Lake).

Deuterium: the basics

• Isotope: Stable hydrogen isotope with 1 proton + 1 neutron.
• Heavy water (D₂O) is ~11% heavier than ordinary water (H₂O) by mass.
• Natural abundance: ~0.015% of hydrogen atoms in natural water (very low → needs enrichment).

H₂S–H₂O Bi-thermal (Girdler Sulfide) Process—how it works (in simple steps)

• Uses counter-current isotope exchange between hydrogen sulfide gas (H₂S) and water (H₂O) in two towers at different temperatures:
  1. Cold tower (~25–35 °C): Equilibrium favors transfer of D from water → H₂S.
  2. Hot tower (~120–140 °C): Equilibrium flips, favoring D from H₂S → water.
• By circulating the streams between cold and hot towers, deuterium concentrates in the water leaving the hot tower.
• The slightly enriched water then undergoes further enrichment (e.g., distillation/electrolysis) to produce heavy water (D₂O).
• Safety note: H₂S is toxic & flammable → stringent containment, scrubbing, gas monitoring.

Why extract Deuterium?

• Nuclear/fusion: Fuel component (e.g., D–T concepts); moderator/coolant roles via D₂O in some reactor types.
• Science & industry:
  • Tracer in environmental/physiological studies (body composition, water turnover, breastfeeding efficacy, vitamin A intake risks).
  • Spectroscopy (isotopic labeling), pharma/chemistry (kinetic isotope effects), certain industrial processes.

India—sites & significance

• Manuguru (Telangana): Uses Godavari water as feed.
• Kota (Rajasthan): Uses Rana Pratap Sagar lake water.
• Strengthens strategic autonomy in heavy-water and deuterium needs for nuclear & research programmes.