Disclosed is a membrane bioreactor system capable of minimizing the energy consumption while guaranteeing excellent membrane cleaning effect. According to the membrane bioreactor system of the present invention, a filtration apparatus for solid-liquid separation is provided in an aerobic tank and a portion of fine bubbles supplied to increase the dissolved oxygen of wastewater introduced into the aerobic tank are used for cleaning the membrane of the filtration apparatus.

A method for introducing a gas into a liquid, the method including filling a gas volume enclosed below a free surface of the liquid and defined in a downward direction by an enclosed level of the liquid with the gas in sequential pulses wherein the gas simultaneously displaces the liquid top down from a gas lifting channel until the enclosed level of the liquid drops below an inlet cross section of a gas flow out channel; subsequently flowing the gas out of the gas volume downward through the gas lifting channel, a deflection portion adjoining at a bottom of the gas lifting channel, in upward direction through the inlet cross section and through the gas flow out channel adjoining the inlet cross section at a top to the free surface.

A method the filtering a liquid in a membrane filter immersed in the liquid and including membranes, the method including introducing a gas through a gas introduction device into a base of the membrane filter in successive pulses so that the membranes are cleaned wherein the gas introduction device includes a liquid flow channel which vertically penetrates a gas collection cavity and admits the liquid into a bottom of membrane filter; and initially filling a gas volume arranged below a free surface of the liquid and defined in a downward direction by an enclosed level of the liquid with the gas wherein the gas simultaneously displaces the liquid top down from a gas lifting channel until the enclosed level of the liquid drops below an inlet cross section of a gas flow out channel.

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).

A siphon-type air diffusion device for intermittently performing aeration, comprising: at least two siphon-type air diffusion pipes; and an air supply member that supplies air to the siphon-type air diffusion pipes, wherein the siphon-type air diffusion pipe includes a siphon chamber which includes a first siphon chamber and a second siphon chamber on the downstream side of the first siphon chamber, a communication portion which communicates the first siphon chamber and the second siphon chamber with each other, an air diffusion hole which is provided on the downstream side of the siphon chamber, a path which extends from the siphon chamber to the air diffusion hole, and a treatment water inlet which is provided on the upstream side of the siphon chamber, wherein the air supply member includes a distribution pipe which extends in an arrangement direction of the siphon-type air diffusion pipe, and an introduction portion which is branched from the distribution pipe and includes at least one air supply port supplying air to the siphon-type air diffusion pipe, wherein the distribution pipe is provided above the air supply port, and wherein in the air supply port of the introduction portion, the air supply port located at the uppermost position in the vertical direction is provided below a lower end of a partition wall dividing the siphon chamber and the path.

Separation processes using osmotically driven membrane systems are disclosed generally involving the extraction of solvent from a first solution to concentrate solute by using a second concentrated solution to draw the solvent from the first solution across a semi-permeable membrane. Enhanced efficiency may result from using low grade waste heat from industrial or commercial sources. Pre-treatment and post-treatment may also enhance the osmotically driven membrane processes.

Methods, systems, and devices for water treatment or for preventing fouling of components of water treatment systems can include the upstream introduction of nanobubbles in-line and/or in close proximity to a reverse osmosis membrane in the water treatment system. The nanobubbles can bind to and cluster (flocculate) nanoparticles (and possible larger solid particles) so that they can be removed and not foul water purification components such as reverse osmosis membranes. The nanobubbles can also interact with and change some characteristics of nanoparticles and thereby reduce fouling of some system components, such as reverse osmosis membranes, or other components. The systems, methods, and devices disclosed herein can help produce potable water safe for human consumption in a more cost-effective manner, e.g., by reducing maintenance costs and in some cases manufacturing costs.

A filtration unit for purifying or treating fluid that includes one or more membrane units having a permeate section. The permeate section of the membrane units is fed fluid that passes through a sealing insert having a fluid inlet and a passage that discharges in fluid communication with the permeate section. The sealing insert is arranged in a support frame of the membrane unit to form a fluid channel for delivering fluid through the insert and along an outer perimeter surface that maintains performance of the membrane unit during operation.

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 hollow fiber membrane module includes: a hollow fiber membrane bundle; a housing formed with a port for allowing a cleaning gas for the hollow fiber membrane bundle to inflow therethrough for accommodating the hollow fiber membrane bundle; and a diffuser having a receiving surface for receiving the cleaning gas having entered through the port, the receiving surface being formed with diffusion hole for diffusing the cleaning gas to the hollow fiber membrane bundle in housing. The diffuser includes a partition dividing a space under the receiving surface into an inner space and an outer space surrounding the inner space and permitting the cleaning gas having entered through the port to flow thereinto. The diffusion hole is arranged to allow at least a part of the cleaning gas flowing in the outer space to diffuse from the inner space to the hollow fiber membrane bundle.