A hydroelectric power generation system includes at least one penstock extending through the sea floor a predetermined depth into the ground below the sea floor, a turbine connected to an underground distal end of each of the at least one penstock, and an underground reservoir to collect seawater flowing down through the at least one penstock and the connected turbine. The hydroelectric power generation system may be part of a distributed hydroelectric power generation system which includes a plurality of hydroelectric power generation systems, the distributed hydroelectric power generation system additionally including an underground reservoir to collect seawater flowing down through all of the penstocks and connected turbines in the plurality of hydroelectric power systems.

Disclosed is a system for producing magnesium hydroxide including: a generation unit; and a recovery unit connected to the generation unit, wherein the generation unit has a reaction tank in which a calcium hydroxide slurry is added to water to be treated containing magnesium ions to crystallize magnesium hydroxide and to obtain a reaction slurry containing particles of magnesium hydroxide, and a sedimentation tank in which the reaction slurry is reserved to sediment the particles and to separate the reaction slurry into a separation slurry containing the particles at a high concentration and a separation liquid containing the particles at a low concentration, and wherein, in the recovery unit, an alkaline aqueous solution is added to the separation liquid to crystallize magnesium hydroxide and to obtain the reaction slurry and then the reaction slurry is reserved to sediment the particles and to recover the sedimented particles.

A system for producing magnesium chloride includes a removal unit, and a concentration unit that is connected to the removal unit. The removal unit generates feedstock water by removing sulfate ions and sodium ions from treatment target water having seawater as a feedstock. The concentration unit generates a slurry in which magnesium chloride is crystallized by concentrating the feedstock water. The removal unit has a first removal unit which reduces the sulfate ion concentration compared to the sulfate ion concentration in the treatment target water, and a second removal unit which reduces the sodium ion concentration compared to the sodium ion concentration in the treatment target water.

A method for circulating hot air in a solar desalination system includes providing a desalination structure having an air flow path defined between an external surface layer and an internal surface layer. A return flow conduit provides an internal fluid flow path. Saline water is pumped through a center column in a direction from the base towards the peak. The saline water is delivered through a nozzle that extends through a sidewall of the center column to provide a mist within the desalination structure exterior of the center column. An air flow within the air flow path is heated to form a hot air supply. The mist is heated with the hot air supply to form an evaporated fluid. A diverted portion of the hot air supply is delivered into the return flow conduit and mixed with an ambient air to form and heat the air flow.

A hydromagnetic desalination cell including at least one hollow rectangular flow conduit, a first rectangular magnet and a second rectangular magnet each having a north pole face and a south pole face opposite of each other, wherein the first and second rectangular magnets are disposed along a longitudinal axis and on opposite sides of the rectangular flow conduit, a first opening and a second opening on opposite walls of the rectangular flow conduit extending between the first and second rectangular magnets, and a first and second chamber fluidly connected to the first and second openings. A hydromagnetic desalination system and methods of desalinating brine water with the hydromagnetic desalination system are also disclosed.

Provided are a biomineralogical method for removing cesium ions. The method for removing cesium ions, the method comprising: adding metal-reducing bacteria, an iron source, and a sulfur source into a solution containing the cesium ions to convert the cesium ions into a solid mineral incorporating cesium. The method for removing cesium ions according to the present invention has advantages in that the cesium ions may be removed with high efficiency and small volume even in the case in which competing ions are present at a high concentration like sea water.

An anaerobic digestion system may include a material grinding/pulping portion, a hydrolysis portion arranged downstream of the grinding portion, a multiple chamber anaerobic reactor arranged downstream from the hydrolysis portion and including a gas collection and reintroduction system, a collection system for collecting digestate and gas from the anaerobic reactor.

In some embodiments, the present invention provides a recombinant protein comprising an affinity tag configured to attach the recombinant protein to a silicate surface, fused to a hydrogen sulfide scavenging enzyme.

Disclosed is a method for treating water, including the extraction of at least two ionic species, the ionic species including an anionic species and a cationic species and being present in the water to be treated, the method especially including a step of mixing a liquid hydrophobic organic phase and the water to be treated, the water to be treated being in the liquid state, in order to subsequently obtain liquid treated water and a hydrophobic liquid organic phase loaded with the ionic species, and a step of thermal regeneration of the organic phase loaded with chemical species. Also disclosed are compounds and compositions that can be used in the method.

A multi-effect system and a multi-effect method for desalination are provided. The method comprises flowing saline water over a thermally conductive plate of a first evaporation chamber; heating the thermally conductive plate to evaporate the saline water, resulting in vapor; removing the vapor from the first evaporation chamber; compressing, using a compressor, the vapor, thereby creating compressed vapor; pumping the compressed vapor into a first condensation chamber; condensing the compressed vapor in the first condensation chamber, resulting in fresh water. The method further comprises heating, by heat released by the condensing of the compressed vapor, a second thermally conductive plate forming a top of the first condensation chamber and a bottom surface of a next evaporation chamber in a next desalination chamber in the vertical stack of desalination chambers.