Systems and methods for configuring compact desalination RO systems operable for point-of-use applications are disclosed herein. The compact RO system can include a single RO element disposed in a vessel and connected to one or more pumps in a circulation loop that recirculates fluid through the vessel. The compact RO system can reconfigure, combine and/or eliminate one or more components to reduce a footprint of the system. For example, the RO system can utilize pumps having flow valves integrated therein instead of separate pump and valve components. High recovery ratios can be maintained by allowing brine produced by the RO element to exit the system before passing through the pump. In some embodiments, the system can utilize pulse width modulation (PWM) to change a flow rate of the pump within the system to ensure operation at peak pressure and flow rate.

A fluid purification system has cells whose purifying capability can be regenerated. Some of the cells are arranged in series to reach a high level of purification. An automatic valve network is controlled to cycle the cells in a way that levels the loads on each, thereby maximizing the service interval for replacing expired cells, enabling all of the cells to be replaced at the same time after having each contributing approximately equally to the purification load, and operated such that at any one time, at least one cell is regenerated so as to enable continuous up-time.

Algae harvesting and cultivating systems and methods for producing high concentrations of algae product with minimal energy. In an embodiment, an algae harvesting method is provided for performing dead-end filtration in an algae harvesting system having at least one treatment tank defining a plurality of filtration stages including at least a first filtration stage and a second filtration stage. An algae medium is pulled through the hollow fiber membranes such that a retentate and a permeate are produced.

A bipolar electrodialysis (BPED) cell is able to bipolar convert salt solutions into acid and base solutions. However, protons migrate through the anion exchange membranes and tend to neutralize the base solution. In a bipolar electrodialysis system described herein, multiple BPED cells are arranged to provide a multi-stage treatment system. Up to half, or up to one third, of the stages have cells with acid block anion membranes. The one or more stages with acid block anion membranes are located at the acid product output end of the system, where the acid concentration in the system is the highest. Replacing the traditional anion membranes in some of the stages with acid block anion membranes allows higher concentration products to be produced with moderate increase in energy consumption.

A device and method are described for the treatment of blood, which device may be used in conjunction with or in place of a failed Kidney. The device includes an ultrafiltration unit to remove proteins, red and white blood cells and other high molecular weight components, a nanofiltration unit to remove glucose, at least one electrodeionization unit to transport ions from the blood stream, and a reverse osmosis unit to modulate the flow of water, to both the blood and urine streams. In one embodiment, a specialized electrodeionization unit is provided having multiple chambers defining multiple dilute fluid channels, each channel filled with an ion specific resin wafer, and electrodes at the extremity of the device and proximate each of the resin filled dilute channels. By selective application of voltages to these electrodes, the ion transport functionality of a given dilute channel can be turned on or off.

The present disclosure relates to tangential flow filters, membranes, and ultrafiltration membranes, for various applications, including bioprocessing and pharmaceutical applications, systems employing such filters, and methods of filtration using the same. In an aspect, an alternating tangential flow system for continuous processing may include a feed line containing a fluid. A retentate line may be in fluid communication with the feed line. A first diaphragm may be at an inlet of the retentate line configured to pump fluid toward an outlet of the retentate line. A second diaphragm may be at the outlet of the retentate line configured to pump fluid toward the inlet of the retentate line. A membrane may be in fluid communication with the retentate line between the first diaphragm and the second diaphragm. A retentate pump may be at the retentate outlet configured to pump the fluid out of the retentate line.

Disclosed is a porous hollow fiber membrane containing a polysulfone-based polymer as a main component, which has an asymmetric structure in which the inner surface side is dense and the outer surface side is coarse, wherein an average of a minor axis diameter of pores of an inner surface is 20 nm or more and 40 nm or less, an open porosity of the inner surface is 10% or more and 30% or less, and a polymer including a monocarboxylic acid vinyl ester unit is supported on at least one of the outer surface and the inner surface. The present invention provides a hollow fiber membrane which has excellent removing performance of substances to be separated such as viruses, and can be used as a separation membrane having high permeability even in a treatment under low pressure.

The present application relates to a method for preparing a dairy product based on the principle of forward osmosis, the concentrated dairy product prepared by the above method, and a continuous forward osmosis membrane system. Multiple concentration of the target solution is achieved by controlling the osmotic pressure difference between the solutions on both sides of the forward osmosis membrane, no heat source or strong external pressure is introduced, and the main nutrient content and nutrient ratio of the target solution are maintained. Compared with a reverse osmosis membrane concentration and a freeze concentration, the forward osmosis membrane concentration can greatly increase the concentration multiple of the dairy product, reduce the unit energy consumption, save the running cost. The scaled treatment of dairy product concentration is realized, and the microbial indicators, physical and chemical indicators and nutritional indicators of concentrated dairy products can meet the requirements of relevant standards.

A high salinity water purification system and process, including a forward osmosis system and a reverse osmosis or nanofiltration system. A concentrated brine of a zinc or iron complex combined with a salt or acid draws pure water across the FO membrane from the influent water. The diluted brine is pumped through a vessel holding an anionic adsorption media to remove the zinc or iron complex and the resultant brine is passed through the RO or nanofiltration system to obtain purified water and a concentrated brine stream. The adsorption media is regenerated by a rinse cycle using fresh water or water from the RO system, removing the zinc or iron complex adhered to the media. The resultant brine is stored and mixed with the output of the RO system. Charged membrane can be used as a standalone membrane in FO process or in combination with resin or resin embedded membrane.

A reverse osmosis unit for processing a feed solution is provided. The unit includes a pressure vessel includes an inlet end, an outlet end, and a vessel body extending between the inlet end and the outlet end. The reverse osmosis unit further includes a plurality of first membrane modules positioned within the pressure vessel. Each first membrane module of the plurality of first membrane modules has a first salt permeance value. At least one second membrane module is positioned within the pressure vessel and coupled in flow communication to the plurality of first membrane modules. The at least one second membrane module has a second salt permeance value that is different from the first salt permeance value.