Abstract: Disclosed is a membrane module unit in which a plurality of membrane modules is coupled together in parallel by coupling means, the membrane module including a sheet-like filter membrane and holding frame members that hold the filter membrane at two opposed sides of a peripheral edge of the filter membrane, wherein the coupling means clamps the holding frame members at the same sides of the filter membranes together by two opposed clamping members. According to the invention, provided is a membrane module unit in which structure is simple, assembly, disassembly, and maintenance can be easily performed, and a plurality of membrane modules can be reliably coupled together. Provided are also an assembly method, disassembly method, and maintenance method of the same, and a water-treatment apparatus.

Abstract: A hollow fiber membrane module in which a housing body forming the hollow fiber membrane module includes an insertion opening into which end parts of the plurality of hollow fiber membranes are inserted so as to be fixed and held, and an opening portion which exposes open end surfaces of a plurality of hollow fiber membranes inserted from the insertion opening to outside, and a cover that blocks the opening portion of the housing body. According to the present invention, it is possible to provide a housing enabling open end surfaces of hollow fiber membranes to be sealed by easily exposing the open end surfaces of the hollow fiber membranes when the hollow fiber membranes are damaged.

Abstract: The present invention relates to an aeration device provided with: an aeration tube, in the upper part of which multiple aeration holes are formed and which extends in the horizontal direction; and an open-ended tube. One end of the open-ended tube directly or indirectly communicates with an end of the aeration tube and the open end of the open-ended tube opens downward in the vertical direction and satisfies formula (1). The present invention provides: an aeration device, which is capable of uniform aeration, can be placed conveniently, and with which complication of tube placement does not occur easily; an operation method therefor; and a water treatment apparatus provided with the aeration device. (D×d×n)/Q?7.5??(1) (In formula (1), (D) is the internal diameter (mm) of the aeration tube, (d) is the diameter (mm) of the aeration holes, (n) is the number of aeration holes per one aeration tube, and (Q) is the air flow (l/min) of the gas supplied per one aeration tube.

Abstract: The present invention relates to an air diffusion device comprising a tubular main pipe for receiving a supply of air from an air supply device, and a branch pipe connected to the main pipe, wherein the branch pipe is connected at one end to the main pipe and open at the other end, one or more air diffusion holes are formed in the branch pipe, at least some of the air diffusion holes are formed so as to be at the top in the vertical direction when the main pipe is laid horizontally, and the branch pipe is configured so that the opening at the other end faces downward in the vertical direction. According to the present invention, it is possible to provide an air diffusion device in which water to be treated is caused to flow into an air diffusion pipe, thereby allowing closing of the air diffusion holes to be suppressed and sediment to be easily removed in the branch pipe as well as an air diffusion method and water treatment device in which this air diffusion device is used.

Abstract: Provided are a hollow-fiber membrane unit in which the membranes are prevented from decreasing in permeation rate and the membrane area per unit volume has been rendered suitable and which can hence treat water in an increased rate and a hollow-fiber membrane module which is for use in such hollow-fiber membrane unit. The hollow-fiber membrane module comprises either a hollow-fiber membrane sheet composed of hollow-fiber membranes disposed in a sheet arrangement or a stack of such sheets and a box-shaped water collection member which holds the hollow-fiber membrane sheet or stack, wherein one surface of the water collection member has an opening that is filled with a fixing resin (potting resin) and is for fixing the hollow-fiber membrane sheet stack.

Abstract: A hollow fiber membrane module in which a housing body forming the hollow fiber membrane module includes an insertion opening into which end parts of the plurality of hollow fiber membranes are inserted so as to be fixed and held, and an opening portion which exposes open end surfaces of a plurality of hollow fiber membranes inserted from the insertion opening to outside, and a cover that blocks the opening portion of the housing body. According to the present invention, it is possible to provide a housing enabling open end surfaces of hollow fiber membranes to be sealed by easily exposing the open end surfaces of the hollow fiber membranes when the hollow fiber membranes are damaged.

Abstract: Disclosed is a membrane module unit in which a plurality of membrane modules is coupled together in parallel by coupling means, the membrane module including a sheet-like filter membrane and holding frame members that hold the filter membrane at two opposed sides of a peripheral edge of the filter membrane, wherein the coupling means clamps the holding frame members at the same sides of the filter membranes together by two opposed clamping members. According to the invention, provided is a membrane module unit in which structure is simple, assembly, disassembly, and maintenance can be easily performed, and a plurality of membrane modules can be reliably coupled together. Provided are also an assembly method, disassembly method, and maintenance method of the same, and a water-treatment apparatus.