A thermo-sensitive draw solute including a polyoxyalkylene adduct represented by a general formula (1): R.sup.1O(AO).sub.nR.sup.2 (1), where R.sup.1 denotes a residue after withdrawal of a hydroxy group from a monovalent alcohol having a carbon number ranging from 6 to 13, R.sup.2 denotes a hydrogen atom or denotes an alkyl group or an alkenyl group having a carbon number ranging from 1 to 13, AO denotes an oxyalkylene group having a carbon number ranging from 2 to 4, n denotes an average added mole number of an alkylene oxide ranging from 1 to 235, and where n is two or more, the two or more AOs may be the same or different from each other.

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 draw solute for forward osmosis membrane process, comprising an addition polymer obtained by addition polymerization of an alkylene oxide having 2 to 10 carbon atoms to an amine compound.

According to one embodiment, a working medium is provided. The working medium includes a first amine compound and a second amine compound. The first amine compound is a tertiary amine compound which consists of a carbon atom, a nitrogen atom and a hydrogen atom, and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is in a range of 7 or more to 9 or less. The second amine compound is a tertiary amine compound which consists of a carbon atom, a nitrogen atom and a hydrogen atom, and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is in a range of 5 or more to less than 7.

A draw solute may have a low viscosity, and can be circulated during a forward-osmosis water treatment, and has a sedimentation under heating and a higher osmotic pressure than that of seawater, when used as a draw solution. A draw solute may include at least one of vinyl ether polymer containing an oxyethylene chain in a side chain and having a number average molecular weight (Mn) of 13,000 or less.

The high water recovery hybrid membrane system for desalination and brine concentration combines nanofiltration, reverse osmosis and forward osmosis to produce pure water from seawater. The reject side of a nanofiltration unit receives a stream of seawater and outputs a brine stream. A permeate side of the nanofiltration unit outputs a permeate stream. A feed side of a reverse osmosis desalination unit receives a first portion of the permeate stream and outputs a reject stream. A permeate side of the reverse osmosis desalination unit outputs pure water. A draw side of at least one forward osmosis desalination unit receives the reject stream and outputs concentrated saline solution. A feed side of the at least one forward osmosis desalination unit receives a second portion of the permeate stream and outputs a dilute saline stream, which mixes with the first portion of the permeate stream fed to the reverse osmosis desalination unit.

A process for the generation of power is disclosed. The process comprises receiving a wastewater stream containing organic matter and passing the wastewater stream to an anaerobic digester in which the organic matter contained therein is broken down to produce biogas. The liquid content of said wastewater stream is reduced before said stream enters the anaerobic digester by passing the wastewater stream through an osmotic power unit. The said stream is passed over one side of a semi-permeable membrane which permits the passage of water but not the passage of salts, an aqueous stream of higher salinity than said wastewater stream being passed over the other side of said membrane such that latent osmotic energy present in said aqueous stream of higher salinity is converted into electricity.

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

The high water recovery hybrid membrane system for desalination and brine concentration combines nanofiltration, reverse osmosis and forward osmosis to produce pure water from seawater. The reject side of a nanofiltration unit receives a stream of seawater and outputs a brine stream. A permeate side of the nanofiltration unit outputs a permeate stream. A feed side of a reverse osmosis desalination unit receives a first portion of the permeate stream and outputs a reject stream. A permeate side of the reverse osmosis desalination unit outputs pure water. A draw side of at least one forward osmosis desalination unit receives the reject stream and outputs concentrated saline solution. A feed side of the at least one forward osmosis desalination unit receives a second portion of the permeate stream and outputs a dilute saline stream, which mixes with the first portion of the permeate stream fed to the reverse osmosis desalination unit.

A method of treating a fluid comprises introducing a feed fluid stream comprising multiple materials to first side of a semi-permeable membrane. A draw fluid stream having a higher temperature than the feed fluid stream is introduced to second, opposing side of the semi-permeable membrane to form a thermal gradient across the semi-permeable membrane. One or more of the multiple materials of the feed fluid stream is drawn through the semi-permeable membrane and into the draw fluid stream via thermal gradient osmosis. A fluid treatment system and a thermal gradient osmosis apparatus are also described.