Provided is a feed spacer, in which angles of strands are differently formed in one feed spacer according to a flow direction of raw water, so that a differential pressure decrease region and a recovery increase region are separated to perform multiple functions, and a reverse osmosis filter module including the feed spacer.

The invention relates to a system and method of use for concentrating a solution that is eluted from an ion exchange process (elution solution) during an ion exchange regeneration using the osmotic pressure of the salt saturator. This method recovers solvent from the elution solution that could be used in a future ion exchange regeneration process. The concentration of the elution solution may include the precipitation and removal of solids from the elution solution.

The disclosed technology includes a water filtration unit. A disclosed water filtration unit includes a filtration unit housing defining a filtration unit cavity; an inlet coupled to the filtration unit housing; a pump positioned at least partially within the filtration unit cavity and including a pump inlet and pump outlet, the pump inlet coupled to the inlet; a filter housing positioned at least partially within the filtration unit cavity and including a filter inlet and filter outlet, the filter inlet coupled to the pump outlet and filter outlet coupled to a water dispenser; and a power source in communication with the pump to power the pump to push water through the filter housing when the water filtration unit is coupled to a water source.

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.

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.

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.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

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.

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.