The hollow fiber membrane module contains a hollow fiber membrane bundle having bundled hollow fiber membranes, a housing with an internal space formed in which the hollow fiber membrane bundle is housed and a gas supply portion which disperses cleaning gas for the hollow fiber membrane in the internal space. The internal space has an upper space in which an upper-side part of the hollow fiber membrane is positioned and a lower space in which a lower-side part of the hollow fiber membrane is positioned. The gas supply portion is provided with pipe vent holes which disperse gas in the housing at a position in the upper space and diffusing vent holes which disperse gas in the housing at a position below the lower space.

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.

A method for controlling a hollow fiber nanofiltration membrane system with controllable power consumption, including the following steps. A filtration flow rate is determined by the program control system according to preset working conditions and the electricity price and the inlet water temperature obtained by a first monitoring module when the hollow fiber nanofiltration membrane assembly is started to perform a filtration process. The inlet water pressure change and the permeability change are monitored and recorded by a second monitoring module during the filtration process. A flushing mode and a flushing intensity of the cleaning system are determined by the program control system according to the inlet water pressure change and the permeability change during the filtration when the filtration process is completed.

Methods of inducing or controlling particle motion in suspensions and colloids are described. In one aspect, a method of inducing particle motion in a suspension comprises contacting the suspension with a gas phase to establish at least one interface between the gas phase and continuous phase of the suspension. One or more gases of the gas phase are transferred across the interface to provide a solute gradient in the continuous phase, the solute gradient inducing motion of the suspended particles.

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 CF1 for filtering dialysis fluid comprises the following: a housing 52 inside of which a filter material 51 is accommodated and which is vertically long; an introduction port 53 that is disposed in the lower part of the housing and that introduces dialysis fluid from an upstream-side flow path 23a; a filtered fluid lead-out port 54 through which filtered dialysis fluid, which has passed through the filter material, is lead out from the upper part of the housing to a downstream-side flow path 23b; and an unfiltered fluid lead-out port 55 through which unfiltered fluid is lead out from the upper part of the housing to a waste fluid flow path 57. When removing the filter from a dialysis fluid circuit 4, fluid is suctioned from the inside of the housing via the upstream-side flow path by using fluid suction means 64A, and a gas is caused to flow into the housing from at least either one of the waste fluid flow path and the downstream-side flow path by using gas inflow means 65. The fluid may be suctioned from the downstream-side flow path and the gas may be caused to flow in from the upstream-side flow path, or the fluid may be suctioned from the waste fluid flow path and the gas may be caused to flow in from the downstream-side flow path. Residual fluid in the filter can be reduced.

A renal therapy apparatus includes a blood filter, a blood pump, a treatment fluid pump, and a control unit configured to control at least one of the blood pump or the treatment fluid pump during a filter cleaning sequence. In a first phase of the filter cleaning sequence, a first fluid including a blood-compatible and physiologically safe fluid is transferred back and forth across the insides and/or outsides of the blood filter. After the first phase, a second fluid is formed by mixing the first fluid with air. In a second phase of the filter cleaning sequence, the second fluid is transferred across the insides and/or outsides of the blood filter at least one time.

Methods of inducing or controlling particle motion in suspensions and colloids are described. In one aspect, a method of inducing particle motion in a suspension comprises contacting the suspension with a gas phase to establish at least one interface between the gas phase and continuous phase of the suspension. One or more gases of the gas phase are transferred across the interface to provide a solute gradient in the continuous phase, the solute gradient inducing motion of the suspended particles.

A peritoneal dialysis apparatus includes a filter and a dialysis fluid circuit in fluid communication with the filter. The peritoneal dialysis apparatus also includes a pump for pumping fresh dialysis fluid to a peritoneum of a patient via the dialysis fluid circuit and pumping used dialysis fluid from the peritoneum of the patient through the dialysis fluid circuit and the filter. The peritoneal dialysis apparatus further includes a selective air access in fluid communication with the dialysis fluid circuit and a control unit configured to control the pump during a peritoneal dialysis treatment and a filter cleaning sequence. The control unit forms a fluid mixture during a filter cleaning sequence by opening the selective air access to mix air with a physiologically safe fluid. The fluid mixture is transferred across insides and/or outsides of the filter at least one time.

A water treatment apparatus is provided with: a treatment vessel into which a solution of interest S is fed; a hollow fiber membrane which is immersed in the solution of interest S in the treatment vessel and has gas permeability; and a biological membrane which is formed on the outer surface of the hollow fiber membrane and utilizes oxygen-containing air fed into the hollow fiber membrane. In the water treatment apparatus, the solution of interest S is treated with the biological membrane. The water treatment apparatus is also provided with a gas-diffusing tube which is located below the hollow fiber membrane and ejects a washing gas to wash the biological membrane; and an oxygen concentration meter which measures the oxygen concentration in discharged air that has passed through the hollow fiber membrane.