A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water to one or other of at least two feed chambers, each feed chamber having a delivery pipe for delivering feed water to a reverse osmosis or nanofiltration; a pump to deliver the feed water from one of the chambers through its associated delivery pipe to the reverse osmosis or nanofiltration to create a concentrated feed stream and a product water stream; return pipes for selectively returning the concentrated feed stream to one or other of the at least two feed chambers; a product water outlet for removal of the product water; and means for switching the delivery of the concentrated feed stream between the selectable return pipes upon detection of a predetermined reduction in efficiency within one or another of the feed chambers.

The present invention relates to a process for the preparation of an aqueous solution comprising at least one earth alkali hydrogen carbonate, a process for the mineralization and/or stabilization of water as well as the use of the aqueous solution comprising at least one earth alkali hydrogen carbonate obtained by the process for the mineralization and/or stabilization of water.

Raw liquid is fed along a raw liquid and drain liquid mixing line to a liquid purification device. Drain liquid is fed along a recirculation line to be mixed with raw liquid. After a set period of time, the liquid purification process is interrupted to flush the liquid purification device by a liquid to remove contaminants built up on the inside surface of the liquid purification device. Downstream of the liquid purification device, the liquid is discharged at high speed into a drain. Prior to flushing, the purification process is interrupted at least once for a time sufficient to enable disruption of a polarized layer of contaminants. A mixture of raw liquid and drain liquid is used as the liquid medium for flushing such that less raw liquid is used for flushing and the service life of the water purification device increases.

The disclosure relates to a method for fermentation integrated with separation and purification of acetone, butanol, and ethanol (ABE) or butanol alone, comprising the following steps: 1) obtaining ABE by fermentation using an acetone-butanol-producing bacterium or obtaining butanol using a butanol-producing bacterium; 2) using a “vapor-stripping-vapor-permeation” method (briefly VSVP) for online separation and purification of ABE or purifying butanol from the fermentation broth; wherein the VSVP method comprises the following steps: introducing a gas bubble into the fermentation broth comprising active cells for fermentation to vaporize ABE or Butanol; subjecting the gas along with the vaporized ABE or Butanol to a membrane separation unit to pass through the membrane; recovering ABE or Butanol, or subjecting ABE or Butanol to a next separation device. By using the disclosed method, production, separation, and purification efficiency of ABE or butanol are improved with saved energy consumption and without increasing equipment investment.

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.

A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water (FW) to one or other of at least two feed chambers (2,4), each feed chamber having a delivery pipe (2i, 4i) for delivering feed water to a reverse osmosis or nanofiltration (8); a pump (6) to deliver the feed water from one of the chambers (2, 4) through its associated delivery pipe (2i, 4i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW); return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concentrated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmospheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).

A method for highly concentrating aqueous solutions containing thermally sensitive organic constituents and with or without mineral constituents, wherein firstly, a major portion of the water is extracted by membrane filtration from the solution for pre-concentration and is discharged from the process and the solution which is pre-concentrated is then subjected to a freeze concentration procedure, in which, in the form of separated ice crystallisate, further water is extracted from the solution. To promote results, that concentration may be effected in the freeze concentration procedure until a viscosity of the mother solution of at least 0.0002 m.sup.2/s is achieved, and in that the separated ice crystallisate from the freeze concentration with the mother solution adhering thereto as a suspension is returned to the membrane filtration upstream of the membrane filtration or after melting of the ice crystallisate.

A process to remove nitrates and chrome from water. The process includes the steps of passing incoming nitrate and chrome contaminated water through a nanofiltration membrane. Retentate liquid rejected from the nanofiltration membrane is pumped to effluent or returned to the nanofiltration membrane. Permeate from the nanofiltration membrane is sprayed through a well screen upper collector above an open atmospheric bed having strong base ion exchange resin. The permeate is pumped through the ion exchange resin and through a gravel layer beneath the resin. The strong base ion exchange resin is periodically regenerated.

A tubular membrane is provided with a vortex generator at an upstream end of the tubular membrane. A spacer with multiple vortex generators may be added to module having a plurality of tubular membranes. A cap over the spacer may have separate inlets for a feed water and gas mixture and recirculating retentate. A system for membrane filtration includes a tubular membrane, a vortex generator, a liquid pump, a gas pump, and a retentate recirculation loop. In a filtration process, a gas is pumped into a flow of a feed liquid to produce a two-phase flow wherein the liquid is the continuous phase. The two-phase flow passes through the vortex generator and through a lumen of the tubular membrane. A continuous gas phase forms in part of the lumen of the tubular membrane. Contaminants in the liquid may be biased towards the continuous gas phase.

Embodiments disclosed herein are directed to methods and systems for treating wastewater via forward osmosis. By way of example, the methods and systems disclosed herein may be used to filter one or more precipitated salts and/or other particles from wastewater generated by power plants such as flue gas wastewater, oil and gas wastewater, and other industrial processes. For example, the methods and systems disclosed herein may be used to filter one or more precipitated salts from a wastewater feed concentrate formed during the forward osmosis process that is recirculated through at least one membrane module to continue the forward osmosis process. Filtering the one or more precipitated salts from the wastewater feed concentrate helps limit clogging of open channel feed spacer(s) of the at least one membrane module.