A process for isolating .sup.17O from water and a process for concentrating .sup.17O by using the same are provided. The process for isolating .sup.17O from water includes: mixing .sup.17O-containing water with formaldehyde to prepare an aqueous formaldehyde solution; heating the aqueous formaldehyde solution to generate a vapor mixture containing water vapor and formaldehyde vapor; and obtaining .sup.17O-depleted water, residual formaldehyde, and a gas mixture containing hydrogen and .sup.17O-enriched carbon monoxide, through photodissociating the vapor mixture. An .sup.17O-enriched water production process includes: an operation of adding hydrogen to the gas mixture to induce a catalytic methanation reaction to synthesize methane (CH.sub.4) and .sup.17O-enriched water (H.sub.2.sup.17O) through methanation, the operation being carried out following the process for isolating .sup.17O from water.

The present application discloses a device for multistage continuous preparation of deuterium depleted water, which includes a feeding pump, a plurality of stages of separation systems connected in series, and a receiver, all of which are connected in sequence. Each stage of separation system comprises a distillation column, a vapor-liquid separator, a low-pressure steam compressor, a stream delivery pump, a three-way valve, and a stream output pipe. The present application further discloses a method for preparing deuterium depleted water, wherein natural water is fed into the device of the present disclosure, and the liquid phase stream continuously flows backwards stage by stage under the combined action of the low-pressure steam compressors and the stream delivery pumps. In a single-stage system, the deuterium is deprived depending on the difference in vapor pressure between .sup.1H.sub.2O and .sup.2H.sub.2O (and/or .sup.1H.sup.2HO), and finally, the deuterium depleted water is produced.

A method of separating heavy water from normal through application of acoustic pressure shock waves to a fluid including heavy water and normal water and recovering separated normal water.

A method of separating heavy water from normal through application of acoustic pressure shock waves to a fluid including heavy water and normal water and recovering separated normal water.

Utilizing the fact that a predetermined adsorbent adsorbs light water at an initial desorption rate higher than heavy water and semi-heavy water, deuterium depleted water having a reduced concentration of heavy water and semi-heavy water is produced easily and in a short time. A method for producing deuterium depleted water by removing heavy water and semi-heavy water from water, the method including: a desorption process in which a relative pressure around a predetermined adsorbent with adsorbed water vapor is reduced, and in which water vapor desorbed from the adsorbent is recovered during a period of time when a desorption rate of light water>a desorption rate of the heavy water and semi-heavy water.

Utilizing the fact that a predetermined adsorbent adsorbs light water at an initial desorption rate higher than heavy water and semi-heavy water, deuterium depleted water having a reduced concentration of heavy water and semi-heavy water is produced easily and in a short time. A method for producing deuterium depleted water by removing heavy water and semi-heavy water from water, the method including: a desorption process in which a relative pressure around a predetermined adsorbent with adsorbed water vapor is reduced, and in which water vapor desorbed from the adsorbent is recovered during a period of time when a desorption rate of light water>a desorption rate of the heavy water and semi-heavy water.

In an embodiment, a method of concentrating a hydrogen isotope, comprises delivering a fluid comprising the hydrogen isotope to be concentrated and an additional gas other than then hydrogen isotope to an anode of an electrochemical cell comprising a hydron exchange membrane comprising hydrons of the hydrogen isotope, and also comprising said anode on a first side of the hydron exchange membrane, a cathode on a second side of the hydron exchange membrane, and an electrical circuit connection between the anode and the cathode; removing a first stream in fluid communication with the cathode, the first stream comprising concentrated hydrogen isotope; and removing a second stream in fluid communication with the anode, comprising the additional gas delivered to the anode depleted of the hydrogen isotope.

A method of separating material, such as foam, sludge, oil or grease, at a fluid's surface, by applying acoustic pressure shock waves to the material and the fluid's surface such that acoustic pressure shock waves are propagated in liquid medium of the fluid and in gas medium above the fluid surface.

A method of separating material, such as foam, sludge, oil or grease, at a fluid's surface, by applying acoustic pressure shock waves to the material and the fluid's surface such that acoustic pressure shock waves are propagated in liquid medium of the fluid and in gas medium above the fluid surface.

A method of activating and dewatering sludge through application of acoustic pressure shock waves to wastewater.