A system and process for concentrating a lithium stream is disclosed. The lithium stream is directed to a reverse osmosis unit which produces a concentrate containing lithium compounds. The RO concentrate is directed through two pressure retarded osmosis (PRO) modules connected in series. The two PRO modules further concentrate the RO concentrate and at the same time yield a diluted brine that is effective to drive an energy recovery device. The RO concentrate leaving the PRO modules is directed to an osmotically assisted reverse osmosis (OARO) module which also further concentrates the RO concentrate.

The invention relates to a process and apparatus for separation of gas mixtures with reduced maintenance costs. The process and the apparatus consist of a feed stream separation stage (1), and a retentate separation stage (2), of which both are membrane separation stages, wherein the first retentate stream (7) is heated to temperature higher than the temperature of the feed stream (5), before it is introduced to the retentate separation stage (2), and the total capacity of the membranes used in the retentate separation stage (2) is higher than the total capacity of the membranes used in the feed stream stage (1).

The present invention provides a multi-stage filter system suitable for the production of drinking water from a wide variety of contaminated water sources. The modular nature of the multi-stage filter system allows for the customization of filter combinations according to the remediation requirements. The multi-stage filter system comprises a coarse filter (S1); an ultrafiltration filter (S2); a graphene-based filter (S3); and a residual nanoparticle filter (S4). The graphene-based filter cartridge comprises few-layer graphene powder; a combination of few-layer graphene powder and pellets comprising a mixture of polyethersulfone, graphene oxide (GO), and dimethylformamide; a composite comprising chitosan, GO, sodium sulfate and ferric chloride; or a combination of few-layer graphene powder, granular activated carbon and a composite comprising chitosan, GO, sodium sulfate and ferric chloride.

A reverse osmosis desalination system has a combined displacement pump and displacement pressure recovery motor that propagate feed water with a structurally fixed recovery rate and structurally stabilized volume flow through continuously alternating discharging and recirculation intervals. Thereby enabled is an instantaneous discharge of the entire feed water concentrate and unmixed replacement with low salinity source water that intermittingly and effectively flushes the reverse osmosis membranes. This in turn provides for high recirculation peak salinity and recovery rate that are simple and reliably controlled without impairing membrane longevity.

A crossflow filtration unit for continuous diafiltration of a feed fluid for obtaining a retentate and a permeate, a corresponding method for diafiltration and the use of the crossflow filtration unit are provided. The crossflow filtration unit includes a diafiltration channel, a flat first filter material, a retentate channel, a flat second filter material, and a permeate collection channel, arranged such that the flat first filter material delimits the diafiltration channel and the retentate channel from one another, and the flat second filter material delimits the retentate channel and the permeate collection channel from one another. The diafiltration channel is fluidly connected to at least one inlet for the diafiltration medium, the retentate channel is fluidly connected to at least one inlet for the feed fluid and to at least one outlet for the retentate. The permeate collection channel is fluidly connected to at least one outlet for the permeate.

A method for desalination is provided. An electric potential difference is applied across a saline solution, where a salinity of the saline solution is in a range of 2.5 to 7.8 parts per thousand. The saline solution is separated, using electrodialysis, into a concentrated saline solution and a first diluate. The concentrated saline solution is transferred to a reverse osmosis chamber. The concentrated saline solution is pumped through a partially permeable membrane, thereby removing salt ions from the concentrated saline solution, and creating a second diluate and a brine solution. A pressure of the solution is then increased, using a pressure exchanger, by transferring water pressure from the brine solution to the concentrated saline solution. The first diluate and the second diluate are combined, where a first recovery ratio of the first diluate is greater than a second recovery ratio of the second diluate.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

This disclosure relates generally to process filtration systems, and more particularly to systems utilizing tangential flow filtration.

Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

A system, method and device are disclosed for bio-processing a feed stream and providing a constant output by operating a continuous single-pass tangential-flow process. The single-pass process provides high conversion concentration while operating at relatively low feed flow rates, and the process can also be used to provide constant output diafiltration.