This lithium recovery device 10C is provided with a processing tank 1 that is partitioned into a supply tank 11 and a recovery tank 13 by a lithium ion-conducting electrolyte membrane 2. In order to selectively move Li+ to an aqueous solution RS in the recovery tank 13 from an aqueous solution SW in the supply tank 11, the aqueous solution SW containing Li+ and other metal ions Mn+, this lithium recovery device 10C is also provided with: a first power supply 51 which is connected between a first electrode 31 that has a porous structure and is arranged so as to be in contact with a supply tank 11-side surface of the electrolyte membrane 2 and a second electrode 32A that is arranged within the recovery tank 13, in such a manner that the first electrode 31 functions as the positive electrode; and a sub power supply 53 which is connected in series to the positive electrode of the first power supply 51, while having the positive electrode thereof connected to a sub electrode 41 that is arranged within the supply tank 11 at a distance from the electrolyte membrane 2.

An electrodialysis desalination device includes a first electrode including a first-stage side; a second electrode including a first-stage side; and a first stage between the first-stage side of the first electrode and the first-stage side of the second electrode. The first stage includes at least one first-stage cell pair positioned between the first-stage side of the first electrode and the first-stage side of the second electrode, and each cell pair includes a pair of first-stage selectively permeable ion-exchange membranes with alternating selectivity that define first-stage channels on opposite sides of each first-stage membrane for respective flows of a first-stage diluate stream and a first-stage concentrate stream. A single pump is configured to pump the diluate streams and the concentrate streams through the first stage.

A nano check valve osmosis and energy collection method and device are provided, which includes principles and methods of osmosis and energy collection technology proposed based on principles of nano check valves and osmotic effects. By providing two semipermeable membranes and filling a solution, cooperating with a concentration control module, solution concentrations at interfaces of the semipermeable membranes are regulated. This ensures that concentrations near the two semipermeable membranes are different, allowing for regulation of osmotic pressure and creation of a check valve effect. It automatically rectifies disordered, high-speed thermal motion of solvent molecules into an orderly unidirectional flow, forming potential energy of the liquid level or kinetic energy of liquid flow for energy storage or power generation. The device can extract molecular thermal kinetic energy from the environment to generate electricity, without consuming energy resources or increasing the Earth's temperature rise.

The present disclosure discloses a system and a method for solar-driven photothermal seawater desalination and ion electroosmosis power generation. In the system, a first reservoir is provided with a first electrode immersed in seawater; a second reservoir is connected to the first reservoir via a cation selective nanofilm; a third reservoir is provided with a second electrode immersed in seawater, and the third reservoir is connected to the second reservoir via an anion selective nanofilm; and an adjustable sun-visor shields the cation selective nanofilm to form a first preset part of solar illumination and shields the anion selective nanofilm to form a second preset part of the solar illumination. Therefore, the cation selective nanofilm and the anion selective nanofilm are each under an asymmetric illumination to generate a temperature gradient.

A submersible water desalination apparatus includes a plurality of water separation membrane elements, a product water collector that receives product water from the membrane elements, and a variable output motorized submersible pump having a suction side that receives product water from the product water collector and a discharge side that pumps product water away from the apparatus through a product water conduit for surface or subsurface use. An automatic control or coupling is employed to reduce the pump output upon the occurrence or onset of suction side cavitation, and discourage or prevent cavitation over a range of product water flow rates from the membrane elements.

A forward osmosis filtration cell is provided which includes a fluid passageway and a forward osmosis filtration membrane positioned within the passageway. The filtration membrane divides the fluid passageway into two chambers, a first chamber configured to hold a draw solution, and a second chamber configured to hold a feed solution. The filtration cell further includes a first electrode positioned in the first chamber, and a second electrode positioned in the second chamber. The first and second electrodes are configured to apply an electric field across the filtration membrane to prevent fouling on the filtration membrane. A method of using a forward osmosis filtration cell in a water treatment system, and a method of retrofitting a water treatment system with first and second electrodes are also provided.

Disclosed is a mobile water filtering system that is compact, lightweight, and capable of producing pure healthy water for numerous people in remote locations. In addition, the mobile water filtering system can include desalination so that ocean water can be purified to create drinking water. The system uses a low resistance sediment filter and a low resistance impurity filter prior to reverse osmosis filtration. Remineralization is provided of the filtered reverse osmosis water. A portable pump can be used together with a voltage regulator that allows application of a wide range of voltages from various voltage supplies.