Disclosed herein are apparatuses and methods for semi-permeable membrane cleaning. In particular, a pressure retarded osmosis (PRO) process redirects raw solution and fluid streams in such a way as to cause periodic changes of the process from PRO to reverse osmosis (RO) for lifting and detaching fouling. Further disclosed is applying, at least periodically, a pulsed-flow regime in the fluid stream, thereby causing increased shearing force for enhanced evacuation of the foulant. Additionally, a backward wash may be provided by injection, for a predetermined injection time, of additional solution selected in such way that net driving pressure becomes RO opposite to normal PRO operation, thereby providing a backward flow from a first side of the membrane to a second side of the membrane, so as to lift and evacuate foulant.

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.

Enhanced cleaning of a fouled membrane is achieved via controlled deformation in a method wherein a feed composition, comprising a solvent and dissolved components, flows into a retentate side of a membrane module. The solvent passes through the membrane from the retentate side to a permeate or draw side of the membrane module while retaining the dissolved components on the membrane. As a foulant accumulates on either side of the membrane, a driving force is generated across the membrane, wherein the membrane responds cyclically by deforming back and forth toward the permeate or draw side and toward the retentate side. The foulant is dislodged from the membrane via mechanical fatigue at the foulant-membrane interface caused by the deformation of the membrane and contact with a spacer in contact with the membrane.

The invention relates to a method for cleaning a filter element made of a porous material. The method comprises directing ultrasound to the filter element, and directing after a predefined time from starting of the ultrasound an impulse to a filtrate reservoir causing filtrate inside the filtrate reservoir to be forced inside the filter element in order to remove particles from the surface of the filter element. Pressure of the impulse is between 4 to 8 times higher than the forward pressure and also that the reverse flux, measured in volume per area time, caused by the impulse is at the minimum 2 to 8 times the feed flux. The invention also relates to a filtering device comprising a filter element made of a porous material.

The present disclosure relates to hollow fiber tangential flow filters, including hollow fiber tangential flow depth filters, for various applications, including bioprocessing and pharmaceutical applications, systems employing such filters, and methods of filtration using the same.

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 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. The blood filter includes a plurality of hollow fiber membranes. During the filter cleaning sequence, a fluid mixture is formed by mixing air with a blood-compatible and physiologically safe fluid. Also during the filter cleaning sequence, the fluid mixture is transferred across insides and/or outsides of the plurality of hollow fiber membranes at least one time. The use of the fluid mixture enables the filter cleaning sequence to be performed during the blood treatment.

Apparatus for in-line liquid exchanging a biomolecule-containing liquid is provided. The apparatus comprises a means for mixing at least two liquids comprising a multiple inlet flow-controller, the means for mixing also comprising an outlet in fluid connection with a tangential flow filtration device configured in single-pass mode.

A method and apparatus for improved separation and containment of radioactive particulates from liquids by filtration. The improvements are achieved by utilizing more than one stage of filtration to remove radioactive particulates from a fluid. The first stage of filtration is designed for high liquid flowrate, low differential pressure across the filter medium, and reversibility of flow through the medium to facilitate backwashing. The second or more stages of filtration receive the backwash flow and captured particulates from the first stage at a lower flowrate, but at high pressure using a high-pressure pump configured between the stages.

Apparatus and method for semi-permeable membrane cleaning in particular, applying series of pulsed water stroke, made simultaneously with osmosis backward flow causing superposed membrane directional shaking and fouling detachment. Pulsed water stroke provided by water stroke generator as several momentum sharp changes in gauge pressure and induce velocity pulse of residual brine flow. The pulsed water strokes ideally induce resonance in the membrane. Osmosis backward wash may be provided either by injection for predetermined injection time, additional solution selected in such way that net driving pressure becomes opposite to normal osmotic operation thereby providing a backward flow of permeate towards to the side opposite to normal operation mode, so as to lift said foulant, or by throttling permeate exiting from the permeate enclosure, until the net driving pressure value become equal to zero, during application of precise synchronized and opposing brine and permeate pressure strokes thereby providing a plurality of quick RO-FO-RO process changes. These procedures allow a membrane to be kept continuously clean and operate at higher recovery.