Method for producing deuterium depleted water, method for separating heavy water and light water, and method for producing deuterium concentrated water

A method for producing deuterium depleted water by removing heavy water and semi-heavy water from water, the method comprising:

• a desorption process in which a relative pressure of water vapor around a predetermined adsorbent with adsorbed water vapor is reduced, and in which water vapor desorbed from the adsorbent, having a deuterium concentration lower than water vapor adsorbed by the adsorbent is recovered only during a period of time when a desorption rate of light water>a desorption rate of the heavy water and semi-heavy water.

A method for separating water into light water, heavy water, and semi-heavy water, the method comprising:

• reducing a relative pressure of water vapor around a predetermined adsorbent with adsorbed water vapor;
• and
• desorbing, from the adsorbent, water vapor having a deuterium concentration lower than water vapor adsorbed by the adsorbent during a period of time when a desorption rate of the light water>a desorption rate of the heavy water and semi-heavy water.

A method for producing deuterium concentrated water by removing light water from water, the method comprising:

• a desorption process in which a relative pressure of water vapor around a predetermined adsorbent with adsorbed water vapor is reduced, and in which water vapor having a deuterium concentration lower than water vapor adsorbed by the adsorbent is desorbed from the adsorbent during a period of time when a desorption rate of the light water>a desorption rate of heavy water and semi-heavy water, thereafter recovering water remaining in the adsorbent and having a deuterium concentration higher than the water vapor adsorbed by the adsorbent.