This disclosure provides systems, methods, and apparatus related to water desalination. In one aspect, a method includes generating a diluted draw solution using forward osmosis. Wastewater is on a first side of an osmotic membrane and a draw solution is on a second side of the osmotic membrane. The draw solution comprises a mixture of water and an ionic liquid. Water in the wastewater diffuses across the osmotic membrane to the draw solution to form the diluted draw solution. The diluted draw solution is heated using a photonic heater to a temperature above a lower critical solution temperature (LCST) of the ionic liquid to phase separate the diluted draw solution into the ionic liquid and treated water.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth-bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

An example separation system includes a stack of membrane plate assemblies. An example membrane plate assembly may include membranes bonded to opposite sides of a spacer plate. The spacer plate may include a first opening in fluid communication with a region between the membranes, and a second opening in fluid communication with a region between membrane plate assemblies. Adjacent membrane plate assemblies in the stack may have alternating orientations such that bonding areas for adjacent membranes in the stack may be staggered. Accordingly, two isolated flows may be provided which may be orthogonal from one another.

Embodiments described herein relate to methods and systems for dewatering solutions via forward osmosis.

The present invention provides for the use of recirculation loops in single- or multi-stage electrical desalination processes such as Ion Concentration Polarization (ICP) desalination and concentration processes.

Described is a method for concentration and extraction of gas field chemicals. The method includes collecting produced water from a gas oil separation plant, treating the produced water to remove oil, and receiving a feed solution containing a gas field chemical and water. The treated produced water is used as a draw solution to concentrate and absorb water from the feed solution using a forward osmosis chamber. A concentrated feed solution containing the gas field chemical and a diluted draw solution is produced. The concentrated feed solution is extracted and stored for injection into gas wells.

The invention relates to 100% renewably-powered desalination/water purification stations for universal applications, the station is disruptive, scalable, amphibious and deportable to seawater, brackish or spill oil sites for simple wave-powered and autonomous operations, the station has a mooring assembly with pumping-purification—delivery subsystems powered by wave and solar energies, the pumping subsystems has the simplest, most efficient wave push/pull pump mechanisms powered by amplified wave centrifugal forces, the mechanical purifications has turbine filters, reverse-osmosis filters, forward-osmosis filters and relief valves to backwash buildups without releasing brine, release water through collecting spill oil, the solar thermal purifications are provided with distilling processes under vaccine conditions, the delivery subsystems with wave turbines and solar panels for generating electricity, propellering and transferring the stations for delivering fresh waters to destinations under GPS guide with the lowest LCOW.

An online cleaning system for micro-polluted nanofiltration membranes uses forward osmosis, and a process of the online cleaning system, and relates to the field of water treatment membrane separation technique. The online cleaning system includes a nanofiltration raw water tank, a nanofiltration membrane assembly, a pure water tank, a forward osmosis feed solution tank, a forward osmosis draw solution tank, a first saline water tank, a second saline water tank and a water bath temperature control device. Some embodiments include cleaning of the nanofiltration membranes that is realized by using forward osmosis as a nanofiltration membrane cleaning system, and cyclic regeneration of the nanofiltration membranes can be realized, so that the purposes of removing dissolved organic matters in micro-polluted raw water, reducing hardness of calcium and magnesium and prolonging the service life can be achieved.

The present invention relates to a method for treating an aqueous liquid effluent containing calcium and carbonate ions and containing precipitation-inhibiting products, said process comprising the following successive steps: a) providing an aqueous liquid effluent supersaturated with CaCO.sub.3 and containing precipitation-inhibiting products; b) having the effluent obtained in step a) pass into a reactor with high solid content with a solid content maintained between 20 and 800 g/l and integrated solid-liquid separation, at a pH comprised between 8 and 9.2 allowing in a single step precipitation in situ of the aragonite polymorph of calcium carbonate and removal of the precipitation-inhibiting products; c) recovering an aqueous liquid supernatant containing a suspended solids content of less than or equal to 0.1% by mass of the solid content in the reactor, advantageously a suspended solids content of less than 50 mg/l, the precipitation-inhibiting products being phosphonates.

According to aspects of the present disclosure, systems and methods are provided for producing hydrogen and oxygen gases by water hydrolysis, which include: a vessel having a first chamber and a second chamber; a membrane permeable to water ions, the membrane separating the first chamber and the second chamber, wherein the membrane is effective to substantially exclude passage of salt ions, and wherein the membrane is optionally permeable to water; an anode in contact with an anolyte in the first chamber; a cathode in contact with a catholyte in the second chamber; and a power source of direct current operably linked to the cathode and the anode; wherein the anolyte comprises a negative ion inert to oxidation and further wherein the catholyte is a saline solution, brackish water, or seawater.