An immersed membrane system or process may use measured or calculated process information to optimize one or more process operating parameters to improve performance or reduce operating costs. An on-line process control system or method may use the resistance in series method in operating an immersed membrane water treatment system. A process control system or process may consider resistance values and adjust operational parameters such as membrane aeration frequency factor, membrane aeration flow, permeate flux, permeation duration, backwash flow and duration, relaxation duration or maintenance or recovery chemical cleaning frequencies in order to reduce the operational costs related to membrane fouling removal.

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 control method is provided for a filter system, which includes at least one filter element (2). The method includes continuously recording a total energy consumption (E.sub.G) during a filtration cycle (22) of the filter system. The total energy consumption (E.sub.G) includes at least of the energy consumption (E.sub.B) for a physical cleaning (24) and the energy consumption (E.sub.P) for the subsequent production cycle (23) up to a predefined, in particular current point in time. The method further includes computing a relative energy consumption (E.sub.rel) by way of division of the recorded total energy consumption (E.sub.G) by a net permeate volume (Q.sub.N) which has been produced during the filtration cycle (22) up to the predefined point in time and starting a physical cleaning (24) in dependence on the relative energy consumption or of a characteristic value derived from this.

A filtration module according to an embodiment of the present invention includes a plurality of hollow fiber membranes held while being aligned in one direction and a pair of holding members that fix both ends of the hollow fiber membranes. In the holding members, an existence region where the hollow fiber membranes exist has a rectangular shape in a direction perpendicular to the direction in which the hollow fiber membranes are aligned; a ratio of an average length of the existence region in a long side direction to an average length of the existence region in a short side direction is 10 or more and 50 or less; an average outer diameter of the hollow fiber membranes is 1 mm or more and 6 mm or less; and a ratio of an average effective length of the hollow fiber membranes between the holding members to the average length of the existence region in the short side direction is 40 or more and 200 or less.

An aeration diffuser (12) for a pressurized liquid treatment module includes a base having a gas passageway (32) and a liquid passageway (50) fluidically separated from the gas passageway. Liquid is injectable into the liquid passageway of the base of the diffuser. Liquid flows through the base of the diffuser and into the module to be filtered by filtration membrane(s) within the module. Gas is injectable into the gas passageway of the base of the diffuser. Gas flowes through the base of the diffuser separately from the liquid to aerate the filtration membrane(s) within the module. Further a module including one or more diffusers and a method of filtration is disclosed.

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t−1), where K is a gain (K>1), and Q(t−1) is an amount of inflow of the water-to-be-treated during a time period t−1 immediately prior to the time period t.

A separation-membrane module 1 includes an element block 2 that is formed by arranging, in parallel, a plurality of separation-membrane elements 4 that are formed by arranging a pair of separation-membranes with their respective permeate surfaces in opposition to each other and sealing the edges of the pair of the membranes; and an aeration block 3 that includes an aeration pipe 31 and that is disposed under the element block 2. In the element block 2, at least one upper spacer 8 is disposed in the upper portion of each space between the adjacent separation-membrane elements 4, and a lower spacer 9 is disposed under the upper spacer 8 in each space between the adjacent separation-membrane elements 4. And the leftmost and the rightmost separation-membrane elements 4 of the plurality of the separation-membrane elements 4 are secured to a frame 12 at the lower spacers 9.

Disclosed herein are aspects and embodiments of an apparatus for providing gas slugs in a liquid. In one example, the apparatus comprises a housing defining a chamber, a bell tube including a wall and an open upper end disposed within the chamber, a riser tube including a wall, an open lower end, and a flared open upper end disposed within the bell tube, and a conduit defined between the wall of the bell tube and the wall of the riser tube and in fluid communication with an internal volume of the riser tube.

Assembly for treating fluids, comprising a support (12) having a first and second oppositely arranged surfaces (121) for backing support of a semi permeable membrane (11), a first fluid conveying compartments (124) interposed between the first and second surfaces, a plurality of first fluid passages (126) extending from the first surface (121) and being in fluid communication with the first compartments (124), and a first duct attached to the support (12) and in fluid communication with the first compartments. The assembly comprises a second compartment (125) arranged for conveying fluid and different from the first compartment, and a second duct attached to the support (12) and configured to be in fluid communication with the second compartment (125).

Algae harvesting and cultivating systems and methods for producing high concentrations of algae product with minimal energy. In an embodiment, a dead-end filtration system and method includes at least one tank and a plurality hollow fiber membranes positioned in the at least one tank. An algae medium is pulled through the hollow fiber membranes such that a retentate and a permeate are produced.