An energy-saving filtering system and a hollow fiber membrane module for the same are disclosed. According to the filtering system of the present invention, pretreated feed water flows into the case of the hollow fiber membrane module by gravity, and the filtrate passing through the hollow fiber membrane is discharged from the hollow fiber membrane module by gravity.

A membrane separation device is provided with membrane modules comprising multiple membrane elements, a frame body accommodating the membrane modules stacked in multiple stages, a stopper for closing an end portion of the frame body to prevent the membrane modules accommodated in the frame from being released, and elastic members which, arranged in a state of elastic deformation in the vertical direction in the frame with the end portion of the frame being closed, suppress vertical vibration of the membrane modules accommodated in the frame, whereby making it possible to avoid vibration of the membrane modules inside the frame body even if the volume of the membrane modules accommodated in the frame body varies.

Methods for cleaning water filtration membranes by treatment with a DNase containing cleaning composition. Optionally the composition also comprises a biocidal and/or other enzymes such as proteases. The DNAse may be derived from Aspergillus oryzae or from Bacillus licheniformis.

A membrane separation type activated sludge treatment method according to an aspect of the present invention includes a step of performing biological treatment on waste water and a step of performing membrane separation on water having been treated in the biological treatment step. The membrane separation step employs a plurality of filtration modules including a plurality of hollow fiber membranes arranged adjacent to one another and oriented in one direction and a pair of holding members fixing both ends of the plurality of hollow fiber membranes, and a plurality of cleaning modules supplying air bubbles from beneath the filtration modules. An amount of treated water sucked by the filtration modules and an amount of air bubbles supplied by the cleaning modules are varied in response to variations in an inflow rate of the waste water in the biological treatment step.

An aerator apparatus including a housing having an inner cavity formed therein, which includes at least one side wall and an upper surface portion connected to the at least one side wall. Additionally, the aerator apparatus includes a first partition wall formed inside the inner cavity and extends from a first lower end to a first upper end to form a first cavity portion and a second cavity portion. Furthermore, a second partition wall is formed between the first partition wall and the first side wall inside the inner cavity, and is extended from a second upper end to a second lower end to form a first chamber and a second chamber in the second cavity portion.

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.

The present disclosure relates to an external pressure type hollow fiber membrane component, a filtration membrane component, and a membrane filtration assembly, and provides an external pressure type hollow fiber membrane component, comprising: a housing having an inner cavity; and two end parts respectively provided at two ends of the inner cavity of the housing, the end parts being provided with a plurality of void passages running through the end parts in the axial direction of the housing and a plurality of water collection passages communicated with each other, and the void passages and the water collection passages are staggered at intervals. The present disclosure also provides a filtration membrane component and a membrane filtration assembly.

A membrane filter for submerged operation for filtering a liquid, the membrane filter including membrane units and a gas distribution system for distributing a gas to the membrane units and flushing the membrane units, wherein each of the membrane units includes a respective gas inlet opening and at least one membrane element, the at least one membrane element including membranes for filtering a liquid permeate from the liquid, a permeate collection cavity connected to permeate sides of the membranes, and a permeate outlet configured to drain the permeate from the permeate collection cavity, the gas distribution system including exactly one gas outlet for each of the membrane units, the exactly one gas outlet configured to exhaust the gas from the gas distribution system into a respective gas inlet opening of each of the membrane units.

A filter unit according to the present invention includes a plurality of filtration modules and a plurality of air bubble generation modules. Each filtration module includes a plurality of hollow fiber membranes extending in an up-down direction and arranged side by side in a curtain shape and a pair of holding members to which top and bottom ends of the hollow fiber membranes are fixed. The air bubble generation modules discharge bubbles toward the hollow fiber membranes. The filtration modules are arranged in parallel at intervals. each air bubble generation module has a discharge port that is disposed between lower holding members of a pair of adjacent filtration modules and above bottom ends of the lower holding members.

Disclosed are system and method for filtration which can minimize the contamination of the filtering membrane through a pretreatment and perform the pretreatment and the filtration with a filtering membrane in a single filtering unit so that any need for separate and additional space and facility for the pretreatment can be obviated. The system for filtration of the present invention comprises a fine bubble supplier for providing fine bubbles into the feed water. The pretreatment is performed by supplying the feed water to be treated into the filtering unit through a dynamic filtration layer which is formed in the filtering unit as the fine bubbles rise.