A system for treating a source of water contaminated with PFAS is disclosed. The system includes a PFAS separation stage having an inlet fluidly connectable to the source of water contaminated with PFAS, a diluate outlet, and a concentrate outlet and a PFAS elimination stage positioned downstream of the PFAS separation stage and having an inlet fluidly connected to an outlet of the PFAS separation stage, the elimination of the PFAS occurring onsite with respect to the source of water contaminated with PFAS, with the system maintaining an elimination rate of PFAS greater than about 99%. A method of treating water contaminated with PFAS is also disclosed. The method includes introducing contaminated water from a source of water contaminated with a first concentration of PFAS to an inlet of a

PFAS separation stage, treating the contaminated water in the PFAS separation stage to produce a product water substantially free of PFAS and a PFAS concentrate having a second PFAS concentration greater than the first PFAS concentration, introducing the PFAS concentrate to an inlet of a PFAS elimination stage; and activating the PFAS elimination stage to eliminate the PFAS in the PFAS concentrate. A method of retrofitting a water treatment system as described herein is also disclosed. The method includes providing a PFAS elimination module as described herein and fluidly connecting the PFAS elimination module downstream of a PFAS separation stage.

A purification system is for purifying a mixture containing a first solvent, a second solvent, and an impurity. The purification system includes a first membrane separation device including a pervaporation membrane and a second membrane separation device including a filtration membrane. The pervaporation membrane separates the mixture into a first permeated fluid and a first concentrated fluid. The first permeated fluid has a lower concentration of the impurity than that in the mixture, and the first concentrated fluid has a higher concentration of the impurity than that in the mixture. The filtration membrane separates the first concentrated fluid into a second permeated fluid and a second concentrated fluid. The second permeated fluid has a lower concentration of the impurity than that in the first concentrated fluid, and the second concentrated fluid has a higher concentration of the impurity than that in the first concentrated fluid.

Systems and methods for filtering materials from biologic fluids are discussed. Embodiments may be used to filter cerebrospinal fluid (CSF) from a human or animal subject. In an example, CSF is separated into a permeate and retentate using a tangential flow filter. The retentate is filtered again and then returned to the subject with the permeate. During operation of the system, various parameters may be modified, such as flow rate and waste rate.

A water treatment system 100 includes: a filtration device 16 that includes an RO membrane element 12 and an NF membrane element 14, and treats raw water containing sodium chloride by the RO membrane element 12 and the NF membrane element 14 to generate concentrated raw water; and an electrolytic device 18 that is disposed downstream of the filtration device 16 and electrolyzes the concentrated raw water to generate water containing sodium hypochlorite.

A reverse osmosis arrangement is described, the first chamber (5) having a first port (7) and a second port (8) and the second chamber (6) being connected to a permeate outlet (9), wherein the first port (7) is connected to a first pump (13). Such a reverse osmosis arrangement should be operated with high efficiency. To this end the second port (8) is connected to a second pump (14).

A system for treating a tetraalkylammonium hydroxide-containing liquid having a high-pressure type reverse osmosis membrane device concentrating a liquid to be treated containing tetraalkylammonium hydroxide at a concentration side, and a line for supplying the concentrated liquid to be treated by the reverse osmosis membrane device to an evaporator further concentrating the concentrated liquid to be treated.

Liquid solution concentration methods and related systems involving osmosis units and energy recovery are generally described. In some embodiments, an osmotic system has a pump, a first reverse osmosis unit, a second reverse osmosis unit, and one or more energy recovery devices. Various embodiments are directed to features such as balancing streams, recirculation streams, and/or valving that alone or in combination may afford improved energy efficiency and/or system performance. Some embodiments may improve performance of certain types of energy recovery devices in combination with osmosis units, such as isobaric or turbine energy recovery devices.

An automated modular filtration system, particularly for low volume tangential flow filtration processes, comprises a plurality of filtration modules formed as separate assemblies and at least one control unit for jointly controlling filtration processes of individual filtration units. Each filtration module contains at least one individual filtration unit for executing a filtration process independent of the other filtration units, first input ports for receiving a first type of fluids, second input ports for receiving a second type of fluids, and exit ports for outputting unused system fluids. First type fluids are process fluids are specific to the filtration processes executed in individual filtration units. Second type fluids are system fluids not specific to filtration processes executed in the individual filtration units. The second input and exit ports establish inter-module connections so system fluids can be forwarded from one filtration module to an adjacent filtration module of the filtration system.

A process for purifying a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant, comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.

A modular element for making reverse osmosis filtering devices includes: at least one first container and a second container, each of which is provided with a tubular lateral wall, with a bottom plate which closes a first axial end of said lateral wall, with an inlet, with a first outlet and with a second outlet, the first and second containers being arranged so that the respective lateral walls are arranged adjacent and have mutually parallel central axes, and a scavenging duct which connects the second outlet of the first container with the inlet of the second container, the first container, the second container and the scavenging duct are obtained as a single monolithic body.