Disclosed herein are aspects and embodiments of an apparatus for securing hollow fiber filtration membranes in a filtration module. In one example, the apparatus comprises a restraining structure engaging elongate portions of the plurality of hollow porous membrane fibers and an anchor formation engaging the plurality of hollow porous membrane fibers and positioned closer to eye portions of the plurality of hollow porous membrane fibers than at least a portion of the restraining structure. Neither the anchor formation nor the restraining structure sealingly engage open ends of the plurality of hollow porous membrane fibers.

In a purification method for purifying contaminated water, the contaminated water contained in a purification tank is filtered by a membrane module disposed in the purification tank. An adsorption agent with powdered activated carbon is added to the purification tank at a raw side of the membrane module. The membrane module is aerated by inflow of air from below. The steps of filtering, adding, and aerating are carried out in parallel and/or sequentially. The purification method is used as a stage of a purification process of a wastewater treatment plant prior to introducing the water purified by the purification method into a river, lake or the ocean.

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.

Systems and related methods for purging air burst supply piping of accumulated water prior to delivering pulses of pressurized air to an interior of a screen intake through the air burst supply piping. The systems and methods can include a purge compressor delivering a purging air supply at a head pressure slightly above a head pressure of water in the air burst supply piping, wherein the head pressure of the water is equivalent to a depth at which the intake screen. The system and methods can also include a purge line arranged in a parallel orientation to an air burst supply line, wherein both the purge line and the air burst supply line are operably coupled to a pressurized air tank.

A multiple-loop tangential flow filtration apparatus for concentrating fluids is described herein. The apparatus comprises a plurality of tube loops for receiving fluid therethrough, each tube loop comprising a respective filter, and a common feed pump for driving the fluid across each respective filter. The plurality of tube loops are coupled to the common pump via a common feed line.

A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Preferred operating parameters include transmembrane pressure of 5-20 kPa, 1-3 backwashes per day, and a flux of 10-20 L/m.sup.2/h. The membranes are dosed with chlorine or another oxidant, preferably at 700 minutes*mg/L as Cl.sub.2 equivalent per week or less. The small oxidant does is believed to provide a porous biofilm or fouling layer without substantially removing the layer. The media filter may be modified so that backwash wastewater is removed from near the bottom of the tank rather than through backwash troughs above the membrane modules. Membrane integrity testing may be done while the tank is emptied after a backwash.

A bubble generation device intermittently generates large bubbles in a liquid phase. The bubble generation device includes a bubble storing container, a pivot, and a pair of edge portion receivers. The bubble storing container stores bubbles generated by a gas supply nozzle in the liquid. The pivot allows the bubble storing container to pivot thereon, thereby releasing the large bubbles from the bubble storing container. The pair of edge portion receivers receives and blocks an edge portion of the bubble storing container to limit pivot of the bubble storing container. An inside of the bubble storing container is partitioned by a partition that is installed in an axial direction of the pivot.

Provided is a method for washing a hollow fiber membrane module which comprises a hollow fiber membrane for filtering raw water containing a suspended component, said method comprising, in the following order, a first washing step for removing a suspended component that is accumulated on the hollow fiber membrane and a second washing step for carrying out an air scrubbing process in which gas is caused to pass through at least to the raw water side of the hollow fiber membrane, wherein, out of water that existed in the hollow fiber membrane module before washing, water in an amount corresponding to not less than 50 vol % of the capacity of the hollow fiber membrane module is removed in the first washing step.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

A device including a housing having a first side, a second side opposed to the first side, and a wall disposed between the first side and the second side. The wall forms at least a partially enclosed space inside the housing. The device also includes a membrane mounted to the wall inside the housing. The device also includes a drop pipe disposed inside the housing and through or around the membrane, the drop pipe having a proximal end and a distal end, the distal end being closer to the second side than the proximal end. The device also includes a diffuser connected to the distal end of the drop pipe.