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 system and method for increasing the efficiency of a multi-pass nanofiltration system associated with water desalination and mineral extraction. A saline source water is preferably subjected to a first treatment by passage through a first nanofiltration unit, followed by a second treatment by passage through a second nanofiltration unit. At least a portion of the second nanofiltration unit's reject stream is recirculated to the inlet of the first nanofiltration unit, thereby increasing the production of permeate from the first nanofiltration unit, as well as increasing the purity of monovalent ions in the first nanofiltration unit permeate. Further nanofiltration units with one or more recirculated reject streams may be connected in series and/or in parallel with the first and second nanofiltration units.

An object of the present invention is to provide a desalination apparatus in which a high pressure pump can be operated at a high efficient operation point even when temperature, salt concentration or the like of water to be treated vary. The desalination apparatus includes a high pressure pump which is provided in a first flow path and supplies raw water to a first module at high pressure to apply reverse osmotic pressure to a first module and a second module, a third flow path for supplying second concentrated water after separation in the second module to upstream of the high pressure pump in the first flow path, and a fourth flow path for supplying a portion of the first concentrated water after separation in the first module to upstream of the high pressure pump in the first flow path.

An object of the present invention is to provide a desalination apparatus in which a high pressure pump can be operated at a high efficient operation point even when temperature, salt concentration or the like of water to be treated vary. The desalination apparatus includes a high pressure pump which is provided in a first flow path and supplies raw water to a first module at high pressure to apply reverse osmotic pressure to a first module and a second module, a third flow path for supplying second concentrated water after separation in the second module to upstream of the high pressure pump in the first flow path, and a fourth flow path for supplying a portion of the first concentrated water after separation in the first module to upstream of the high pressure pump in the first flow path.

A water treatment assembly comprising a spiral wound hyperfiltration membrane module connected to: i) a feed line adapted for connection to a source of pressurized feed water, ii) a permeate line adapted for connection to a dispenser of treated water and iii) a concentrate line adapted for connection with drain; wherein the assembly further includes a pressurizable reservoir with valves for selectively diverting flow of pressurized feed water along the feed line, through the reservoir and returning to the feed line prior to passing through the hyperfiltration membrane module.

This disclosure relates to the use of a hydrophobic hollow fiber filter for the filtration of cell cultures and other biological perfusions, due to its resistance to fouling, as well as the ability to filter solutions with a high solid content. A hydrophobic hollow fiber filter may be used within a filter housing in conjunction with a process vessel and a traditional separation system. When the system is used with alternating tangential flow or tangential flow filtration, the hydrophobic hollow fiber filter results in more effective filtration of the filtrate, leading to greater concentration of the retentate, even in solution containing high levels of solids.

The present disclosure is directed to methods and systems of purifying solvents. The purified solvents can be used for cleaning a semiconductor substrate in a multistep semiconductor manufacturing process.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

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.