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 reverse osmosis treatment device includes: a first pressure vessel for treating an untreated water to produce a primarily treated water and a first permeated water; a second pressure vessel for treating the primarily treated water to produce a secondarily treated water and a second permeated water; a first cleaning solution tank for storing a first cleaning solution for cleaning the first pressure vessel; and a second cleaning solution tank for storing a second cleaning solution for cleaning the second pressure vessel. Each of the first pressure vessel and the second pressure vessel has therein a reverse osmosis membrane element having a reverse osmosis membrane. The first cleaning solution tank is connected to the first concentrate outlet pipe of the first pressure vessel, and the second cleaning solution tank is connected to the inlet pipe for the primarily treated water of the second pressure vessel.

A filtering core structure having flow guiding and flushing capabilities includes: a wall piece; a filter bottle, disposed on the wall piece, with a top portion of the filter bottle provided with a water input port and a clean water port; a filter core, disposed in the filter bottle, such that water output end of filter core is connected to and in communication with the clean water port; a water input chamber, disposed inside the filter bottle and around perimeter of the filter core; and a flow guiding tube, connected to water input port, and in communication with bottom portion of the water input chamber. In this filter core structure, thrust of water flow is used to flush germs and impurities from the bottom of filter bottle, so that stagnant water will not remain there, in solving the problem of germ multiplication and stinky water.

A hyperfiltration system (10) and method for treating water including: a vessel (20) having a feed inlet (22), a permeate outlet (24), and a concentrate outlet (26); at least one spiral wound membrane element (28) located within the vessel (20); a pump (30) having a low pressure side (32) in fluid communication with a source of feed water (40) through a junction point (42) and a high pressure side (34) in fluid communication with the feed inlet (22); a permeate valve (50) connected to the permeate outlet (24) and adapted to selectively direct permeate flow between a treated water outlet (52) and the junction point (42); a flow path (60) between the concentrate outlet (26) and a discharge (62); and a flow restrictor (64) located along the flow path (60) and adapted to vary resistance to concentrate flow between a high and low value.

A system for and method of cleaning polymeric and ceramic microfiltration and ultrafiltration membranes in hollow fiber, flat sheet, and tubular membrane units is provided. The method includes using a reducing agent, specifically ascorbic acid, based formulation. The method also includes certain protocols useful in conducting such cleanings. The system includes features for facilitating the method of the present invention.

A normal flow filtration system having a housing with one or more filters contained within a bowl and attached to the outlet of the system. Liquid enters the bowl, contacts the surfaces of the one or more filters. Impurities are trapped in the filter and the filtered liquid flows through to the outlet. Parameter(s) such as flow rate, transmembrane pressure drop and/or time are measured and when met, filtration ceases. A backflushing occurs through the filter(s) so as to remove the impurities from the filter. This backwashed material is directed to an outlet of the bowl that is connected to a drain. Additionally a port formed in the side of the housing adjacent an outer surface of the filter(s) can be used to provide a lateral washing of the filter(s). The system is then recirculated in a downstream manner to reestablish equilibrium and filtration is then restarted.

The present invention relates to a water treatment method including: a filtration step of feeding water to be treated to a membrane filtration device having loaded therein a porous separation membrane and performing filtration treatment to obtain filtrate; a discharging step of discharging the water to be treated in the membrane filtration device, which has been separated and concentrated by the porous separation membrane; and a cleaning step of cleaning the porous separation membrane by at least one treatment of physical cleaning and chemical cleaning, in which a cycle including a combination of the filtration step, the discharging step and the cleaning step is repeated multiple times, thereby obtaining filtrate. In each cycle, the filtration step and the discharging step are repeated multiple times, and the cleaning step is then carried out.

A water treatment device includes a sub-reverse osmosis membrane device having a primary casing and a primary reverse osmosis membrane dividing the primary casing into a primary liquid passing part and a primary permeating part; a low pressure water feed pump feeding seawater to the primary liquid passing part at a pressure that is equal to or lower than an osmotic pressure of the seawater; a main reverse osmosis membrane device having a secondary casing and a secondary reverse osmosis membrane dividing an inside of the secondary casing into a secondary liquid passing part and a secondary permeating part; and a high pressure water feed pump feeding a primary treated liquid, which is a resultant product of the seawater passing through and flowing out of the primary liquid passing part, to the secondary liquid passing part at a pressure higher than an osmotic pressure of the primary treated liquid.

The invention relates to a method for the processing of protein-containing suspensions or solutions, for example for concentrating or purifying the protein-containing particles or dissolved protein-containing substance contained in the suspensions or solutions, wherein the protein-containing suspensions or solutions are filtered by means of a filter module and the protein-containing particles or dissolved protein-containing substance retained in the filter module are conveyed out of the filter module by means of a backwashing fluid.

Membrane filtration systems can be used to purify liquid streams for downstream use. In practice, foulant can build-up on the surface of a membrane within a filtration system over time. The effectiveness of the filtration system will deteriorate if the fouling is not properly controlled. In some examples, a method of controlling membrane fouling in a pressurized membrane system involves supplying a feed stream that is predominately air mixed with water to the membrane. In other words, the feed stream a greater volume of air than water, even though it is the water being processed by the membrane. Supplying the pressurized membrane system with a feed stream that contains a greater volume of air than water can yield significantly better performance than supplying the membrane with a feed stream that contains a greater volume of water than air.