The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

A method of treating aqueous, preferably concentrated, waste streams with a unique combination of steps in a way that is easily scalable and able to be used with batch or continuous flows. The method comprises at least the following steps: Adding at least one precipitating agent to the waste water to produce precipitated solids; and removing the precipitated solids from the waste water using a forward flushable membrane to remove the precipitate solids.

An apparatus and a method use permeate to flush a reverse osmosis filter membrane in the same flow direction as when fluid is being filtered through the membrane. The apparatus includes a housing having a membrane positioned therein. The membrane has an interior surface and an exterior surface. The housing has an inlet port located outward of the exterior surface of the membrane and first and second outlet ports. The first outlet port is located outward of the exterior surface of the membrane and the second outlet port is located inward of the interior surface of the membrane. A first pump is used to route pressurized, untreated fluid from a fluid source through the membrane to produce permeate. A second pump is used to route permeate to a desired function while also routing some permeate at low pressure to the housing to flush the membrane.

Provided is a method for washing a hollow fiber membrane module which comprises a hollow fiber membrane for filtering raw water containing a suspended component, said method comprising, in the following order, a first washing step for removing a suspended component that is accumulated on the hollow fiber membrane and a second washing step for carrying out an air scrubbing process in which gas is caused to pass through at least to the raw water side of the hollow fiber membrane, wherein, out of water that existed in the hollow fiber membrane module before washing, water in an amount corresponding to not less than 50 vol % of the capacity of the hollow fiber membrane module is removed in the first washing step.

Filter membranes in systems for drinking water, tertiary water treatment and combined sewage overflow, MBR and MBT are efficiently cleaned without use of air scour. In one system the membranes, preferably flat plate membranes, are cleaned by mechanically driven wipers that can clean the surfaces of two adjacent membranes simultaneously. Another system uses water jets to clean the membrane surfaces.

A bubble generation device is provided which is capable of discharging bubbles of about the same size from each of a plurality of bubble discharge ports. The device is provided with a bubble discharge chamber communicating with each of a plurality of bubble discharge ports, a turnaround path including a first communication port communicating with a gas storage chamber and a second communication port communicating with the bubble discharge chamber on a downstream side in a gas traveling direction of a turn-around point of the turnaround path, opening areas of the plurality of bubble discharge ports being the same as each other, and a total of the opening areas of the plurality of bubble discharge ports being smaller than an opening area of the second communication port.

An apparatus and a method for using permeate to flush a reverse osmosis filter membrane in the same flow direction as when fluid is being filtered through the membrane is disclosed. The apparatus includes a housing having a membrane positioned therein. The housing has an inlet side and an outlet side. The membrane has an interior surface and an exterior surface. The housing has an inlet port located outward of the exterior surface of the membrane, at the inlet side of the housing, and a first outlet port and a second outlet port both located at the outlet side of the housing. The first outlet port is located outward of the exterior surface of the membrane and the second outlet port is located inward of the interior surface of the membrane. A first pump is used to route pressurized, untreated fluid from a fluid source through the membrane to produce permeate. A storage tank holds permeate until needed. A second pump is used to route permeate to a desired function while also routing some permeate at low pressure to the housing to flush the membrane. The flushing occurs when the first pump is turned off. A method of flushing the membrane is also taught.

Embodiments of the present disclosure generally relate to methods for treating porous membranes. In an embodiment, a method of treating a porous membrane is provided. The method includes flushing the membrane with a first fluid comprising a hydroxide ion and hypochlorite ion, flushing the membrane with water, flushing the membrane with a second fluid comprising an organic peroxide, organic peroxide ion, or both, and flushing the membrane with water.

Disclosed is a water purifier. A water purifier according to one example of the present invention includes: a filter unit including a reverse osmosis filter; a water outlet unit including a water outlet member connected to the filter; and a control unit for discharging water filtered by the filter unit to the outside through the water outlet member, wherein the reverse osmosis filter is provided with a reverse osmosis film that divides the reverse osmosis filter into a non-filtering side and a filtering side, and the control unit causes the filtering side to be flushed before the water filtered by the filter unit is discharged through the water outlet member, and can cause the non-filtering side to be flushed after the water filtered by the filter unit is discharged through the water outlet member.

A method for operating a desalting device that has a first desalting device and a second desalting device, said method comprising: a normal operation step for supplying to-be-treated water to the first desalting device so as to separate the to-be-treated water into first concentrated water and first desalted water, and supplying the first concentrated water to the second desalting device so as to separate the first concentrated water into second concentrated water and second desalted water; and a recovery operation step for supplying the to-be-treated water to the first desalting device so as to separate the to-be-treated water into the first concentrated water and first permeate water, and passing dilute water having a lower concentration than the first concentrated water through the second desalting device so as to recover desalting performance of the second desalting device.