A water desalination system includes a first set of ultrafiltration membranes, a second set of ultrafiltration membranes, a first backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with brine generated by a reverse osmosis process, and a second backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with one or more chemicals and reverse osmosis permeate water.

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.

An apparatus includes a filtration skid configured to generate a filtrate through at least one of microfiltration and ultrafiltration. The apparatus further includes a desalination skid fluidly connected to the filtration skid. The desalination skid is configured to perform reverse osmosis desalination on the filtrate to generate a permeate, where the filtrate travels from the filtration skid to the desalination skid without traversing a storage tank. In one embodiment, the apparatus further comprises a controller, where the filtration skid and the desalination skid are integrated to provide self-adaptive operation of the filtration skid and the desalination skid in response to control by at least one of a supervisory controller and a local controller. In one embodiment, the control responds to at least one of temporal variability of feed water quality, a permeate production capacity target, and a permeate quality target.

The disclosure relates to water treatment systems that may be used to remove impurities from water, particularly systems that inserted at the point of entry of a water supply into a building.

A valved raw liquid supply line, which is connected to a filtration unit including a liquid purification unit with an inlet and with outlets for purified liquid and drain liquid, a mixing device, a means for maintaining pressure, a means for maintaining a recirculating flow of liquid, which is located on a line supplying a mixture of raw liquid and concentrate upstream of the liquid purification unit, a recirculating line, a purified liquid line, a drain liquid line, and a control unit, which is connected to the means for maintaining pressure, pressure monitor, the raw liquid supply valve and a drain liquid discharge valve. The means for maintaining pressure is located on a raw liquid supply line upstream of the liquid mixing device. The technical result is a longer system working life, more efficient use of raw liquid, and reduced energy expenditure.

Raw liquid is fed along a raw liquid and drain liquid mixing line to a liquid purification device. Drain liquid is fed along a recirculation line to be mixed with raw liquid. After a set period of time, the liquid purification process is interrupted to flush the liquid purification device by a liquid to remove contaminants built up on the inside surface of the liquid purification device. Downstream of the liquid purification device, the liquid is discharged at high speed into a drain. Prior to flushing, the purification process is interrupted at least once for a time sufficient to enable disruption of a polarized layer of contaminants. A mixture of raw liquid and drain liquid is used as the liquid medium for flushing such that less raw liquid is used for flushing and the service life of the water purification device increases.

A water desalination system includes a first set of ultrafiltration membranes, a second set of ultrafiltration membranes, a first backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with brine generated by a reverse osmosis process, and a second backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with one or more chemicals and reverse osmosis permeate water.

The disclosure relates to water treatment systems that may be used to remove impurities from water, particularly systems that inserted at the point of entry of a water supply into a building.

A water desalination system includes a first set of ultrafiltration membranes, a second set of ultrafiltration membranes, a first backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with brine generated by a reverse osmosis process, and a second backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with one or more chemicals and reverse osmosis permeate water.