Systems, methods and apparatuses to concentrate lithium containing solutions using forward osmosis units are provided, which, for example, can include providing at least one forward osmosis unit having at least one lithium containing solution chamber having at least one first inlet and at least one first outlet, at least one brine chamber having at least one second inlet and at least one second outlet, and at least one selectively permeable membrane positioned between the at least one lithium containing solution chamber and the at least one brine chamber, and conveying a lithium containing solution through the at least one lithium containing solution chamber and a concentrated brine solution through the at least one brine chamber, said conveying causing water from the lithium containing solution to be drawn through the at least one selectively permeable membrane and into the concentrated brine solution, such that a concentrated lithium containing solution exits through the first outlet and a less concentrated brine solution exits through the second outlet.

Described are improved electrodialysis (ED) desalination systems and methods comprising voltage regulation and/or improved stack geometries. The systems and methods provide product water concentrations suitable for drinking (having a total dissolved solids concentration of less than 500 mg/L or 500 ppm) and have a high product recovery ratio.

This specification describes membrane based filtration and softening systems and methods. A system has a microfiltration or ultrafiltration (MF/UF) membrane unit upstream of a nanofiltration or reverse osmosis (NF/RO) membrane unit, optionally with no intermediate tank. In some cases, the system and method may be used with feed water provided at municipal line pressure to the membranes. NF/RO permeate is collected in a tank and then pumped to a header. Treated water may be drawn from the header for use or recycled to the system, for example to backwash or flush one or both of the membrane units. In a combined process, NF/RO permeate flushes the feed side of the NF/RO unit and then backwashes the MF/UF unit. In another process, the MF/UF unit and NF/RO unit are filled with NF/RO permeate before being placed in a standby mode.

Process for providing purified polyether block copolymers comprising polyoxyethylene (PEO) and polyoxypropylene (PPO) moieties wherein the purified product is obtained by an ultrafiltration step of a solution of the polyether block copolymers and wherein the block copolymers are depleted in lower molecular impurities.

The present invention relates to a process for treating aqueous effluents from the primary circuit of a nuclear power plant implementing a separation of boric acid using a reverse osmosis membrane, characterized by the fact that it comprises steps consisting of treating the effluents using a multi-stage assembly composed of reverse osmosis modules comprising a membrane with a high boron rejection rate, arranged in parallel and in series, and recycling of the intermediate products to different points in the assembly.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter and using reverse osmosis.

The invention relates to liquid purification and/or desalination systems, predominantly water from different sources, and is used in household and/or drinking water supply, in suburb and country houses. Liquid purification system, comprising of raw liquid line with the inlet valve, reverse osmosis membrane connected to drainage line and purified liquid line and purified liquid consumption line and purified liquid vessel, secondary purified liquid line, connected to purified liquid vessel and to raw liquid line and to console panel, characterized in that debris layer on the reverse osmosis membrane is near totally dissolved by intensive repeated flushing of the reverse osmosis membrane with purified liquid.

A valve arrangement for reducing the migration of one or more viruses through a filter when feed flow to the filter is resumed after a reduction in the feed flow. The valve arrangement includes an inlet line having an inlet port to be connected to a supply of product and an outlet port to be connected to an inlet of the filter, a pump, an outlet line, and a recirculation system. The recirculation system includes a recirculation line connecting the outlet line and the inlet line, and a check valve disposed along the recirculation line. When the check valve detects the feed flow reduction, a recirculation loop is created such that product is continuously recirculated through the filter during the reduction, thereby ensuring continuous fluid flow through the filter even during the reduction.

An apparatus and process for separating a gas mixture is disclosed. The apparatus includes a plurality of membrane separation stages comprising a first membrane stage, a second membrane stage, and a third membrane stage. Each of the first, second, and third membrane stages are designed to separate a gas stream provided to them into a permeate stream and a retentate stream. The retentate stream provided from the third membrane stage is configured to be withdrawn as a product, further processed, or discarded. The apparatus further includes a gas transport device with an inlet in communication with the gas mixture and an outlet in communication with the first membrane stage. The controller is in communication with at least one measuring device, and the controller adapts a behavior of the gas transport device in response to a measurement of the at least one measuring device.

The present invention relates to a system and process for treating a feedwater wherein the system includes at least one or nanofiltration unit that receives a feed under high pressure and produces a concentrate that is directed to and held at low pressure in a concentrate accumulator. Generally the permeate or the inlet feedwater is maintained at a constant flow rate. Periodically the system is switched from a mode 1 or normal operating process to a mode 2 where the concentrate is drained from the concentrate accumulator. However, in mode 2, the feedwater is still directed into the system and through the RO or nanofiltration unit which produces the permeate and the concentrate.