Photocurable compositions that have a color change during curing and methods of preparation and use of such compositions. More particularly, the present invention relates to photocurable compositions that that have a color change during curing and are useful for forming topographical features, e.g., spacer features, and/or fold protection coatings on a portion of a membrane surfaces, and particularly on membranes used in osmosis and reverse-osmosis applications, such as membrane filters.

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.

An assembly for treating a liquid is provided. The assembly includes a pressure vessel having first and second ends provided with respective first and second endcaps, a membrane element positioned within the pressure vessel, an adapter coupling the first endcap with a first end of the membrane element, a first set of shims positioned between the first endcap and the first adapter, a first thrust collar positioned between the first endcap and the first end of the membrane element, a second thrust collar positioned between the second endcap and a second end of the membrane element, and a second set of shims positioned between the first thrust collar and the first end of the membrane element. An overall thickness of the second set of shims is the same as an overall thickness of the first set of shims.

This publication relates to a method and a system for producing freshwater through a reverse osmosis process in a submerged membrane system requiring a differential pressure over the membrane system. The differential pressure is provided by introducing gas bubbles in the riser device (2) downstream the outlet (7) for fresh water in the riser device (2). The system comprises at least one submerged, reverse osmosis unit (1), with an inlet (4) for water and an outlet (7) for fresh water, a riser device (2) extending from the outlet (7) of the submerged membrane system to at, above or below sea level and a system for providing a low pressure side for the reverse osmosis process.

A plasma activated water production system includes a plasma reactor and a membrane concentrator. The plasma reactor includes an internal cavity, at least one electrically-conductive inlet capillary and outlet capillary. A mixing chamber has a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet. A power source is provided. The plasma reactor propagates a plasma discharge between the inlet capillary and the outlet capillary. A membrane concentrator includes a water flow channel with a water inlet and a water outlet, a dry gas inlet and a humidified gas outlet. An ion selective membrane is provided, and water will pass through the membrane into the dry gas, and the water leaving the membrane concentrator will have increased concentrations of nitrates, nitrites and hydrogen peroxide. An electrodialysis embodiment and a method of generating plasma activated with increased concentration of nitrates, nitrites and hydrogen peroxide are also disclosed.

Apparatus and processes for controlling a reverse osmosis system for water desalination to reduce energy consumption. The system has a controller configured to receive information from the sensor array and determine a fouling parameter for each reverse-osmosis stage based on one or more of: an A-Value, a B-value and a normalized differential pressure. The controller is then configured to control the flow through each of the reverse-osmosis assemblies based on the determined fouling parameters to meet a predetermined criterion for total permeate production for the reverse-osmosis system.

A spiral wound membrane module has a brackish water RO or NF membrane combined with a permeate carrier having a narrow spacing between membrane contacting elements. The membrane may have water permeability (A-Value) of at least 8*10.sup.−5 cm/s/bar at 25° C. The membrane may have salt diffusion rate (B-Value) of at least 0.5*10.sup.−5 cm/s at 25° C. The permeate carrier may have a density of 54 wales per inch or more of a gap between adjacent ribs of 215 um or less. The permeate carrier may have a channel cross-sectional area of 16*10.sup.−9 m.sup.2 or more. Water is fed to the module at a high feed pressure, for example a pressure of at least 50 bar, optionally up to 120 bar. Retentate may be discharged at a concentration of 100 g/L, 130 g/L, or 150 g/L or more.

Spiral wound reverse osmosis devices with reduced lateral leakage and thereby increased salt rejection are made by compacting a microporous layer within a composite reverse osmosis membrane longitudinally along its lengthwise periphery. Means and method for causing longitudinal indentations in composite membranes during manufacturing operations are disclosed and described.

Provided is an apparatus for controlling a seawater desalination plant. The apparatus includes: a dissolved air flotation device configured to provide treated water obtained by treating seawater according to a dissolved air flotation (DAF); an ultrafiltration device including a plurality of ultrafiltration units each having an ultrafiltration membrane, and configured to perform an ultrafiltration (UF) process of filtering impurities remaining in the treated water using the ultrafiltration membranes of the plurality of ultrafiltration units; a reverse osmosis device; an information collection unit; and a state treatment unit.

The disclosure relates to systems, devices, and methods for flow control in a reverse osmosis filtration system, such as within a medical device. The systems, devices, and methods can respond to changes in permeate flow rate and solute concentration by adjusting feed water and concentrate water rates. Multiple feedback loops adjust parameters to meet water flow rate and purity requirements.