Provided is a cell culture apparatus including a culture vessel that stores a cell suspension containing cells; a first filter part that has a first filter membrane that performs membrane separation treatment on the cell suspension extracted from the culture vessel; a first circulation flow path that allows components blocked by the first filter membrane to return to the culture vessel; a second filter part that has a second filter membrane that performs membrane separation treatment on components of the cell suspension permeated through the first filter membrane; a second circulation flow path that allows components permeated through the second filter membrane to return to the culture vessel; and a recovery flow path that recovers components blocked by the second filter membrane. In the cell culture apparatus, an average hole diameter of the first filter membrane is 20 m or smaller, and 0<B/A0.5 is satisfied in a case where an average hole diameter of the first filter membrane is A and an average hole diameter of the second filter membrane is B; or an average hole diameter of the first filter membrane is 20 m or smaller, and the second filter membrane is an ultrafiltration membrane.

Methods of recovering lithium from a lithium source or a lithium-containing material using low pH solutions and membrane technologies to purify and concentrate the recovered lithium. The lithium sources may include a spent lithium-ion battery/cell, a lithium-containing mineral deposit, or other lithium containing materials. The processes described herein recovery the lithium after digestion of the lithium-containing material with a low pH solution through one or more acid-stable, semipermeable membranes.

An integrated, membrane-based process to produce purified water and conversion of salt to high value chemicals from oil and gas well produced water is described. A liquid stream including water and dissolved salt is flowed through pretreatment units and one or more desalination and concentration units which remove at least a portion of the water to form a brine enriched in dissolved salt. The purified high-density brine may be subjected to electrically-enforced salt dissociation techniques to produce chemicals from oil and gas produced water.

A system for treating high temperature produced water includes an electrocoagulation unit, a membrane distillation unit in communication with the outlet of the electrocoagulation unit having a hydrophobic membrane with a feed side for receiving the produced water stream and a product side for receiving a deionized water stream. A heat recovery heat exchanger is in communication with the membrane distillation unit for receiving two streams, one from each side of the hydrophobic membrane, such that heat is exchanged between the two streams. A line leaving the heat exchanger returns a heated stream from the heat exchanger to a location in a line upstream of the membrane distillation unit. A brine tank in communication with the membrane distillation unit receives a portion of a stream from the membrane product side and contains a concentrated brine solution containing the portion of the stream from the membrane product side and sodium chloride.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter.

The present invention concerns a method for cleaning a filtration system under operation. The filtration system comprising a hydraulic circuit Cp recycling the permeate stream to the feed side of the membrane and/or a hydraulic circuit Cr recycling the retentate stream to the feed side of said membrane. The method comprises injecting an amount of a chemical product into the filtration system in the hydraulic circuit Cp or in the hydraulic circuit Cr or upstream of the cross-flow filtration membrane, setting the proportion of recycled permeate stream or recycled retentate stream collected in the hydraulic circuit Cp and/or Cr to enable the recycling of a significant amount of unreacted chemical product having passed through said cross-flow filtration membrane to the feed side of said cross-flow filtration membrane, as well as a filtration system for carrying out said method.

A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

A high recovery variable volume reverse osmosis system where the volume of concentrate cycled through the RO system is reduced in response to recovery levels increasing. By reducing the volume of concentrate cycled through the RO system, this reduces the cycle time of highly saturated concentrate passing through the RO system. Reducing the cycle time of concentrate passing through the RO system tends to minimize or reduce membrane scaling.

Air flows across an air-liquid interface such that liquid desiccant flowing through the interface absorbs water from the air and is thereby diluted to form an output stream. The output stream is circulated through an electrodialytic stack having a central ionic exchange membrane and first and second outer ionic exchange membranes. A redox shuttle loop circulates around the first and second outer ionic exchange membranes. A voltage is applied across the electrodialytic stack, which regenerates the liquid desiccant.

A biogas upgrading system can include a multiple stage membrane system that is configured to remove oxygen so that the biogas is upgraded to have a higher concentration of methane, a pre-selected oxygen (O.sub.2) concentration (e.g. less than or equal to 0.2 mol %, etc.), and a pre-selected carbon dioxide (CO.sub.2) concentration (e.g. less than or equal to 5 mol %, etc.). The membrane system can be configured to reject O.sub.2 by utilizing a low CO.sub.2/O.sub.2 selectivity that is within a pre-determined range (e.g. less than 5 or less than 4.5). In some embodiments, the upgraded biogas that is output from the system can be entirely made up of methane, carbon dioxide, and oxygen. In other embodiments, the biogas can be almost entirely composed of these components along with a small amount of nitrogen and a trace amount (e.g. less than or equal to 0.2%-0.1%, etc.) of other components.