A two-stage filter enclosed within a single vessel is provided. The two-stage filter is provided in the form of the vessel having a first filtration stage configured to capture particles of a first size, and a second filtration stage downstream of the first filtration stage and in fluid communication with the first filtration stage configured to capture particles of a second size, wherein the first size is larger than the second size. The first filtration stage may comprise a porous media. The second filtration stage may comprise one or more membrane filters.

An online cleaning system for micro-polluted nanofiltration membranes uses forward osmosis, and a process of the online cleaning system, and relates to the field of water treatment membrane separation technique. The online cleaning system includes a nanofiltration raw water tank, a nanofiltration membrane assembly, a pure water tank, a forward osmosis feed solution tank, a forward osmosis draw solution tank, a first saline water tank, a second saline water tank and a water bath temperature control device. Compared with convention techniques, some embodiments include efficient cleaning of the nanofiltration membranes that is realized by using forward osmosis as a nanofiltration membrane cleaning system, and cyclic regeneration of the nanofiltration membranes can be realized, so that the purposes of removing dissolved organic matters in micro-polluted raw water, reducing hardness of calcium and magnesium and prolonging the service life can be achieved.

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.

A fluid filtration system includes a fluid storage vessel such as a bioreactor, a filter housing including a filter element disposed therein, a pump coupled between the fluid storage vessel and the filter housing, and a flow diverter disposed between the pump and the filter housing. The pump is configured to move fluid from the fluid storage vessel through the filter element, and the flow diverter is configured for selectively directing fluid received from the pump to the first or second end of the filter housing. In a first mode of operation, the flow diverter directs flow through the filter housing in a first direction, while in a second mode of operation, the flow diverter directs flow through the filter housing in a second direction opposite the first direction.

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.

A filter medium according to one embodiment of the present invention comprises: a first support having a plurality of pores; a nanofiber web comprising nanofibers disposed on upper and lower portions of the first support and forming a three-dimensional network structure, and a hydrophilic coating layer formed on at least a part of an outer surface of the nanofibers, wherein the hydrophilic coating layer is formed of a hydrophilic coating composition comprising a hydrophilic polymer compound having at least one functional group selected from a hydroxyl group and a carboxyl group and a crosslinking agent comprising at least one sulfone group; and a second support having a plurality of pores interposed between the first support and the nanofiber web.

A single-use device for filtration of a large volume of medium including a plurality of single-use filter units, at least some of which, preferably all of which, are connected to each other by rigid pipes. The filter units include at least one prefilter and at least one main filter for virus filtration which is configured as a hollow fiber capsule.

The present invention provides a fresh water generator operating method and a determination program that are employed in a method for cleaning a separation membrane module following membrane filtration, and that, while various cleaning steps such as reverse pressure cleaning, air cleaning, chemical solution cleaning are taking place after completion of the membrane filtration, determines cleaning troubles by calculating a temporal change in resistance increase rate on the basis of an increase in membrane differential pressure.

A system and a method for water purification are provided. An exemplary system includes a multimedia filter, an ozone generator, an ozone contactor coupled to the ozone generator, and a ceramic membrane filter coupled to an air scouring system, wherein the air scouring system is coupled to the ozone generator. A storage tank is coupled to a purified water line from the ceramic membrane filter, wherein the storage tank is coupled to a backwashing line coupled to the multimedia filter.