A high salinity feed water such as seawater is treated to produce a reverse osmosis (RO) concentrate and an RO permeate. Optionally, some or all of the RO concentrate may be filtered to produce a nanofiltration (NF) permeate. Optionally, some feed water can also be filtered to produce NF permeate without first being concentrated by RO treatment. The NF permeate, or a blend of the RO permeate and NF permeate, may be used to produce a product water for injection into an oil-bearing reservoir to enhance oil recovery. Optionally, the product water may have salinity greater than the feedwater, or at least 30 g/L. The product water may have hardness of less than 20 mg/L.

A separation system includes first and second separation parts each having a separation membrane and provided with a fluid supply port, a permeate fluid exhaust port, and a non-permeate fluid exhaust port, an intermediate connecting part for connecting the permeate fluid exhaust port of the first separation part and the fluid supply port of the second separation part, a supply pipe connected to the fluid supply port of the first separation part, in which a mixed fluid flows at a pressure higher than an atmospheric pressure, and a pressure reducing part connected to the permeate fluid exhaust port of the second separation part, for reducing a pressure inside the permeate fluid exhaust port to a pressure lower than the atmospheric pressure. A pressure inside the intermediate connecting part is lower than a pressure inside the supply pipe and not lower than the atmospheric pressure.

The present invention relates to an apparatus and a method for preparing dialyzate, wherein the apparatus has a first part and a second part that is configured as a circuit; wherein the first part comprises a water connection or a water container as well as the primary side of a filter; wherein the filter is configured to prepare purified water from the water through forward osmosis; and wherein the second part comprises the secondary side of the filter, a reservoir, a filtrate line that leads from the secondary side of the filter to the reservoir, and a line leading from the reservoir to the secondary side of the filter, with the reservoir being a container having means for connecting the container to a dialysis machine.

A composite semipermeable membrane 12 of the present invention includes a porous support membrane 12a and a skin layer 12b supported by the porous support membrane 12a. The membrane surface of the composite semipermeable membrane 12 has an elastic modulus of 250 MPa or more and 500 MPa or less as calculated by force curve measurement using AFM in water. A spiral membrane element 20 of the present invention includes the composite semipermeable membrane 12 of the present invention. A water treatment system 100 of the present invention includes the spiral membrane element 20 of the present invention.

The invention relates to a specific process and apparatus for separation of gas mixtures with reduced maintenance costs.

The invention relates to a method and apparatus for treatment of produced or process water from hydrocarbon production to reduce the volume of the produced or process water while simultaneously reducing the salinity of a highly saline stream, for example, the brine from a seawater desalination plant. The method includes causing a feed stream comprising produced or process water to flow through the lumen of a hollow fiber osmotic membrane 4 which is immersed in an open channel 2 or tank of flowing draw solution 6 which has high salinity. In this way, water from the feed stream is drawn through the osmotic membrane 4 by an osmotic pressure differential caused by the difference in salinity between the feed stream and the draw solution 6.

Membrane distillation (MD) systems include at least two MD modules arranged in series, each of at least two MD modules including a condensing media inlet operable to receive a condensing media and a condensing media outlet, a feed inlet operable to receive a feed media and a feed outlet, and a first heating element positioned and operable to heat a feed prior to or upon introduction of the feed to a first of the at least two MD modules, wherein a stream exiting the feed outlet of the first of the at least two MD modules is introduced to the second of the at least two MD modules. Other MD systems include at least two MD modules arranged in parallel.

Water treatment systems including electrically-driven and pressure-driven separation apparatus configured to produce a first treated water suitable for use as irrigation water and a second treated water suitable for use as potable water from brackish or saline water and methods of operation of same.

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.