A hollow fiber membrane for removal of dissolved oxygen from fluid that is made of a porous hydrophobic material and an apparatus for controlling nitrate concentration level in water comprising a membrane contactor having the membrane, the membrane comprises at least one tubular fiber comprising: an outer wall for contacting fluid external to the tubular fiber; at least three inner channel walls for contacting fluid internal of the tubular fiber, wherein each inner channel wall forms a fluid communicating channel; a plurality of pores, wherein pores proximate to surfaces of the outer wall and each inner channel wall are smaller in size than pores non-proximate to said surfaces of the outer wall and each inner channel wall, wherein a central portion of the tubular fiber has a thickness greater than thickness of the tubular fiber outside the central portion.

A wastewater treatment system is provided for improving the efficiency of existing wastewater treatment plants. In accordance with aspects and embodiments, a wastewater system having a source of wastewater, an effluent, a sludge, a first basin configured to receive the wastewater, and a second basin, in fluid communication with the first basin and configured to receive sludge, may be retrofitted with a closed loop working fluid system. A first membrane system may be arranged in the first basin and a second membrane system may be arranged in the second basin, and a working fluid containing a concentration of at least one solute may be pumped through the first and second membrane systems in a closed loop to enhance overall plant efficiency.

A water treatment process (10) includes, in a crystallisation stage (12), passing a saline water feed (16) through an elongate conduit kept in a cold environment at a temperature below the equilibrium freezing temperature of the saline water, forming a slurry of brine and ice crystals inside the conduit, and, in a separation stage (14), separating the ice crystals from a bulk of the brine, producing a brine stream (22) and an ice stream (26). The elongate conduit is of a material, or has an inner material layer in contact with the saline water and with the slurry of brine and ice crystals, with a thermal conductivity of less than 5 W/m.Math.K and has a length configured to ensure formation of the slurry of brine and ice crystals in the conduit at the flow rate of the saline water feed through the elongate conduit.

A filtering device is used for obtaining a chemical liquid by purifying a liquid to be purified and includes an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path that includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion. The filter A has a porous membrane made of ultra-high-molecular-weight polyethylene and a resin layer disposed to cover at least a portion of the surface of the porous membrane, and the resin layer includes a resin having a neutral group or an ion exchange group.

Methods and apparatus provide filtration for concentrating analytes, such as bacteria or exosomes, of a biological sample, such as blood or urine. The technology may employ membrane devices that implement one or more tangential flow filtration processes such as in stages. An example membrane device may typically include a membrane having sides and ends. The membrane may selectively permit constituent(s) of the sample to pass through while retaining other constituents at one side. An input chamber of the device may include an inlet near one end and an outlet near the other end, and that may permit a tangential flow of the sample along the first side surface, and a trans-membrane passing of constituent(s). An output chamber of the device may be configured at the second side surface to receive the passing constituents. Such devices may be provided in a kit to facilitate targeting of a desired biological analyte concentration.

The disclosure relates to enhancing alkalinity of brine, e.g. seawater, using bipolar membrane electrodialysis (BPMED) without removing divalent cations that otherwise cause scaling. In one embodiment, a BPMED is employed wherein the brine volumetric flow rate through a basification compartment is greater at a given current density than that through a brine compartment which increases the pH of the brine output while keeping it below the precipitation pH. In one embodiment, the spacer located in the basification compartment is thicker than spacers elsewhere in the BPMED so as resist membrane distortion due to the increased hydrostatic pressure in the basification compartment given the greater volumetric flow. The brine output having increased alkalinity can be returned to the ocean to mitigate acidification and enable capture of atmospheric carbon dioxide.

A filtration module is provided, the module including at least one filtration packet containing filtration media or one or more membranes, such as a stack of membranes, the at least one filtration packet having one or more fluid ports, the one or more fluid ports being surrounded by a primary seal and a secondary seal spaced from the primary seal. The secondary seals are designed to maintain sterility of the assembly during shipping, handling and/or installation. A removable film may cover one or more fluid ports to maintain sterility prior to use.

Spin columns that include a poly(acid) membrane separation matrix are provided. Also provided are kits that include the subject devices, as well as methods of using the devices, e.g., in sample preparation (such as protein purification) protocols.

Provided is a method for controlling a pH to a neutral range (pH 6 to 8) by adding an alkali or an acid to decarbonated water, including controlling the amount of the alkali or the acid added using an electrical conductivity meter. The decarbonated water is, for example, water obtained by decarbonating industrial water or groundwater so that the concentration of carbonic acid is 10 ppm or less. The method may further have a step of producing pure water by RO treatment of the decarbonated water with a pH adjusted to 6 to 8 by the pH control.

The present disclosure describes methods and systems for separating a fluid. The methods and systems include a plurality of osmosis modules operably coupled together. At least some of the plurality of osmosis modules include an osmosis membrane, a feed side on a first side of the osmosis membrane; a draw side on a second side of the osmosis membrane; a feed inlet operably coupled to the feed side; a draw inlet operably coupled to the draw side; a feed outlet operably coupled to the feed side; a draw outlet operably coupled to the draw side. The at least some of the plurality of osmosis units further including a feed recirculation loop operably coupled to the feed inlet, the feed outlet, and a feed inlet of a downstream osmosis module; and a draw recirculation loop operably coupled to the draw inlet, the draw outlet, and a draw inlet of a downstream osmosis module.