A method for operating a desalting device that has a first desalting device and a second desalting device, said method comprising: a normal operation step for supplying to-be-treated water to the first desalting device so as to separate the to-be-treated water into first concentrated water and first desalted water, and supplying the first concentrated water to the second desalting device so as to separate the first concentrated water into second concentrated water and second desalted water; and a recovery operation step for supplying the to-be-treated water to the first desalting device so as to separate the to-be-treated water into the first concentrated water and first permeate water, and passing dilute water having a lower concentration than the first concentrated water through the second desalting device so as to recover desalting performance of the second desalting device.

The reverse osmosis centrifuge converts rotational energy into fluid velocity and conserves the energy placed into the concentrate. As concentrate travels back towards the center of the reverse osmosis centrifuge, the velocity of the fluid is converted into rotational force, thus conserving energy. To accomplish this, the reverse osmosis centrifuge includes a stationary cylindrical housing having a vacuum chamber and a vacuum pump for generating vacuum pressure in the vacuum chamber, a driveshaft coupled to a membrane cylinder rotatable within the stationary cylindrical housing, the membrane cylinder having a plurality of vertical desalination membranes, and an energy recovery turbine. The reverse osmosis centrifuge can be placed on the concentrate or waste stream outlet of a desalination or reverse osmosis facility to increase freshwater production. Through using the methods described above, plant water production can be increased up to 40%, which in turn has a dramatic effect on plant profitability.

Processes and systems for filtering a liquid sample are provided. Batches of a liquid sample can be routed to two or more cycling tanks (e.g., first and second cycling tanks). Upon filling a first cycling tank, a first batch of the liquid sample can be routed to a filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the first cycling tank or to a collection vessel. Upon filling a second cycling tank, a second batch of the liquid sample is routed to the filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the second cycling tank or to the collection vessel. The filling and continuous diafiltration of batches of the liquid sample continues to alternate between the two or more cycling tanks until a total product volume is processed.

Examples disclosed herein relate to methods and systems for controllably removing one or more solutes from a solution. Examples disclosed herein relate to methods and systems for removing water from alcoholic beverages.

An electrochemical system has a first reservoir receiving a feed stream. The feed stream includes a solvent and a solute different than the salt. A second reservoir receives a brine stream with a higher salt concentration higher than the feed stream. Electrodes contact a loop of redox- active electrolyte material causing reversible redox reactions. The reactions cause the loop to accept a first ion from the salt in the first reservoir and drive a second ion into the brine stream in the second reservoir. Three ionic exchange membranes of alternating type define the first and second reservoirs. A concentrate stream is output from the first reservoir, the concentrate stream having a second solute concentration greater than the first solute concentration.

A system and method for producing from saline source water a product containing an increased ratio of multi-valent ions to mono-valent ions, which includes multiple nanofiltration units arranged to selectively remove mono-valent ions from the water fed into each nanofiltration stage in the nanofiltration permeate stream while retaining multi-valent ions in the nanofiltration reject stream. The rate at which the increase in the multi-valent ion- to mono-valent ion ratio is obtained may be enhanced by introduction of lower salinity water into the nanofiltration reject between stages, and by recirculating a portion of downstream nanofiltration reject flow into an upstream nanofiltration unit. The enhanced multi-valent ion product is suitable for multiple uses, including irrigation of plants and remineralization of desalinated water. The relative concentrations of the multi-valent ions in the product may be adjusted, for example by selection of nanofiltration membrane technologies which have higher or lower rejection for specific multi-valent ions.

Disclosed is a continuous process for the purification of steviol glycosides such as Rebaudioside D and/or Rebaudioside M extracted from the dried stevia leaves or extracted from a fermentation broth using continuous simulated moving bed processes and nanofiltration without the addition of organic solvents to obtain a purified steviol product comprising sweet steviol glycosides. The sweet steviol glycosides can be used as substitutes for caloric sweeteners in beverages and in other food items.

The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that a portion of the overall permeate stream is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device, and the remainder of the overall permeate stream is removed, with the recycled permeate having a higher concentration of the component to be separated off than the removed permeate. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include concentrating a dilute aqueous lithium source to yield an extraction feed having an extraction lithium concentration; extracting lithium from the extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate; concentrating a stream obtained from the lithium intermediate in a concentration stage to yield a lithium concentrate; and converting lithium in the lithium concentrate to lithium hydroxide.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include concentrating a dilute aqueous lithium source to yield an extraction feed having an extraction lithium concentration; extracting lithium from the extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate; concentrating a stream obtained from the lithium intermediate in a concentration stage to yield a lithium concentrate; and converting lithium in the lithium concentrate to lithium hydroxide.