893 results about "Forward osmosis" patented technology

A process for purification of fluids, for example, desalination of seawater or brackish water, using organic solutes in a concentrated water solution for use in a forward osmosis process, to extract fresh water out of salt water through the forward osmosis membrane, and subsequently separating the organic solutes out of the diluted forward osmosis permeate by cloud point extraction, thereby regenerating a concentrated organic solution for recycling to the forward osmosis process, and fresh water for potable water use.

A method and apparatus for desalinating seawater which uses an ammonia bicarbonate forward osmosis desalination process. Seawater is pumped through one side of a membrane assembly. A draw solution is pumped through the other side of the membrane assembly. The draw solution withdraws water molecules from the seawater through the membrane into the draw solution. A draw solution separator receives a heated draw solution which then decomposes into ammonia, carbon dioxide and water. Potable water is separated from ammonia has and carbon dioxide gas. The ammonia gas and carbon dioxide gas are recombined with a portion of the potable water stream to reform the ammonium bicarbonate draw solution.

A filter element for use in a reverse osmosis, nano-filtration, membranes and spacers membrane-bioreactor, forward osmosis, or other filtration system, includes a permeate carrier substrate having a wrapped core tube. The permeate carrier includes a series of spaced ribs. The ribs are formed by application of yarns, strings or resinous or polymeric materials to a membrane substrate. The ribs define channels for passage of a liquid or gas permeate therealong. The permeate is received at the core tube which has one or more elongated flow recesses therealong to facilitate collection of the permeate.

There is disclosed a process and device for Forward Osmosis (FO) Pressurized Device (FOPD) in general and one hydraulically coupled to a reverse osmosis (RO device for a FOPRO (Forward Osmosis Pressurized Reverse Osmosis). Specifically, there is disclosed a passive device (that is, not needed energy input) for using forward osmosis to generate significant hydraulic pressure that can be used to drive a reverse osmosis process, wherein the reverse osmosis process (not needed external energy to run pumps) can separate salt from salt water to generate potable water from water with high salt content (such as sea water, urine, sweat, brackish water and the like).

There is disclosed a membrane formulation having high flux for forward osmosis applications. There is disclosed a forward osmosis filtration membrane having a salt rejection 99+% or greater, and comprising an asymmetric hydrophobic porous backing and cellulosic fibers. The membranes of the present invention find use in a variety of applications including osmotic-driven water purification and filtration, desalination of sea water, purification of contaminated aqueous waste streams, and the like. Specifically, there is disclosed a forward osmosis filtration membrane having a skin layer for salt rejection and a porous scaffold layer having a woven or non-woven mesh embedded within it.

A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer, a hydrophilic polymer layer, and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

An energy-efficient process for dewatering an aqueous organic solution includes using freely available solar energy to concentrate a draw solution within a reservoir. The draw solution is used in conjunction with a membrane to remove water from the organic solution in a forward osmosis process. The draw solution is diluted by the osmosis process, and returned to the reservoir to be re-concentrated and reused in the osmosis process.

Stabilized surfactant-based membranes and methods of manufacture thereof. Membranes comprising a stabilized surfactant mesostructure on a porous support may be used for various separations, including reverse osmosis and forward osmosis. The membranes are stabilized after evaporation of solvents; in some embodiments no removal of the surfactant is required. The surfactant solution may or may not comprise a hydrophilic compound such as an acid or base. The surface of the porous support is preferably modified prior to formation of the stabilized surfactant mesostructure. The membrane is sufficiently stable to be utilized in commercial separations devices such as spiral wound modules.

A method and system using hybrid forward osmosis and nanofiltration is disclosed for treating produced water containing contaminant species. The system comprises a forward osmosis cell and a downstream nanofiltration cell. A draw solution fluid cycles between the forward osmosis cell and the nanofiltration cell. The draw solution contains polyvalent osmotic agents producing polyvalent ions in the draw solution. The passage of monovalent ions through the nanofiltration membrane is hindered due to the presence of conjugate polyvalent ions.

The invention relates to a high-water-flux forward-osmosis composite membrane and a preparation method thereof. The forward-osmosis composite membrane is a polysulfone-sulfonated polysulfone-inorganic filler blended / polyamide composite membrane. A traditional osmosis membrane is generally applied to a reverse-osmosis system, and if the traditional osmosis membrane is used in a forward-osmosis process, the water flux of osmosis is far lower than a theoretical value since the traditional osmosis composite membrane is large in thickness, the hydrophilicity of a supporting layer of a polyamide layer is poor so as to cause serious inner concentration polarization. The preparation method comprises the following steps: blending a polymer with a modifier to form film casting liquid; after scraping or leveling, performing non-solvent coagulating bath with water; by a phase-inversion method, preparing a polysulfone ultrafiltration membrane with good hydrophilicity, high porosity, uniform surface pore structure and narrow pore diameter distribution; and in a clean environment and at room temperature, airing the polysulfone membrane till the surface is dry, and growing a polyamide active layer on the surface of the polysulfone membrane by an interfacial polymerization method, thereby obtaining the forward-osmosis composite membrane with good hydrophilicity, high porosity, low thickness and high mechanical strength. The high-water-flux forward-osmosis composite membrane disclosed by the invention has the advantages that not only the osmosis flux is high, but also the reverse leakage of an extraction medium is low, and the selective permeability is good.

The invention discloses a high-performance flat-type cellulose acetate / graphene blend forward osmosis membrane. 5 to 25 percent by weight of cellulose acetate, 1 to 15 percent by weight of additives, 0.01 to 2 percent by weight of graphene and mixed solvent of dimethylformamide, dimethylacetamide, or N-methylpyrrolidone and acetone are added into a dissolving tank according to a given sequence and are stirred and dissolved for 2 to 18 hours at the temperature of 5 to 75 DEG C to be uniformly mixed so as to prepare a forward osmosis membrane casting solution; the high-performance flat-type cellulose acetate / graphene blend forward osmosis membrane is prepared on a supporting material by adopting a phase inversion method. According to the forward osmosis membrane, 1M NaCl is used as a driving liquid, the deionized water is used as a raw material solution, the flux of pure water of the forward osmosis membrane is more than 21L / m<2> within the test time of one hour, and the salt flux in the reverse direction is less than 3.5g / m<2>.

The invention discloses a novel composite forward osmosis membrane and a preparation method thereof. The preparation method comprises the following steps: coating a casting solution on a low-density non-woven fabric and carrying out phase inversion in a gel bath so as to obtain a porous supporting layer; and allowing an aqueous solution of polyamine and an organic solution of polyacyl chloride to react on the porous supporting layer to form an ultrathin separating layer so as to obtain the composite forward osmosis membrane with a three-layer structure consisting of a low-density non-woven fabric layer, the porous supporting layer and the ultrathin separating layer. According to the invention, through hydrophilic modification of the porous supporting layer and modification of the ultrathin separating layer on the surface, the thickness of the compact ultrathin separating layer is reduced, and water flux is improved. The novel composite forward osmosis membrane prepared in the invention can be used in the process of forward osmosis and has high membrane flux and a high retention rate.

The invention belongs to the field of sewage treatment, and particularly relates to a waste water treatment method and device based on forward osmosis and membrane distillation. The waste water treatment method based on the forward osmosis and membrane distillation comprises a waste water concentration process and a drive liquid circulation process, wherein the waste water concentration process adopts a forward osmosis technology to concentrate waste water with high salt content and high chemical oxide demand (COD) concentration through drive liquid so as to obtain the concentrated waste water and diluted drive liquid; the drive liquid circulation process adopts a membrane distillation technology to dehydrate the diluted drive liquid so as to obtain the purified water and renewable drive liquid; and the renewable drive liquid is repeatedly used for the waste water concentration process so as to continuously concentrate the waste water. Due to the adoption of the method and device for treating the waste water with high salt content and high COD concentration, the waste water of different sources and fields can be treated, and the advantages such as wide applicability for waste water, stability in running and low treatment cost can be realized.

An apparatus, system, and method for desalinating water is presented. The invention relates to recovery of water from impaired water sources by using FO and seawater as draw solution (DS). The seawater becomes diluted over time and can be easily desalinated at very low pressures. Thus, a device consumes less energy when recovering water. The apparatus, system and method comprise an immersed forward osmosis cell.

A bioelectrochemical system includes an anode, a saline solution chamber, and a cathode. The anode is at least partially positioned within an anode chamber containing an aqueous reaction mixture including one or more organic compounds and one or more bacteria for oxidizing the organic compounds. The saline solution chamber contains a draw solution and is separated from the anode chamber by a forward osmosis membrane. Water diffuses across the forward osmosis membrane from the aqueous reaction mixture to the draw solution.

A method and apparatus for separating draw solution solutes and product solvent from a draw solution using a plurality of distillation columns. In one embodiment, the draw solution is used in a Forward Osmosis (FO) water desalination process. In this embodiment, the draw solution is directed to the plurality of distillation columns in parallel while the energy stream (heat) is directed to the plurality of distillation columns in series such that the efficiency of heat use is improved and in turn the cost of the heat is reduced.

A process for purification of fluids, for example, desalination of seawater or brackish water, using organic solutes in a concentrated water solution for use in a forward osmosis process, to extract fresh water out of salt water through the forward osmosis membrane, and subsequently separating the organic solutes out of the diluted forward osmosis permeate by cloud point extraction, thereby regenerating a concentrated organic solution for recycling to the forward osmosis process, and fresh water for potable water use.

The invention discloses a recycling method of high brine waste water based on forward osmosis. The method comprises the following steps: firstly, concentrating high brine waste pretreated through a forward osmosis membrane element, wherein water in waste water enters into a driving liquid from a raw material side of a forward osmosis membrane; and then, concentrating, dehydrating and regenerating the diluted driving liquid obtained through one or more of a membrane distillation membrane element, a membrane distillation evaporation assembly or a low temperature multi-effect evaporation assembly, wherein regenerated driving liquid is recycled in the process of returning to forward osmosis. The method is widely applicable for the type of waste water, and has the advantages of long-term stable operation and low treatment cost.

It is to provide a process for manufacturing potable water from a liquid to be treated, such as seawater by using forward osmosis membrane, wherein the solution after the separation of water from dilute draw solution diluted by the migration of water from the liquid to be treated, is stably regenerated and reutilized and an apparatus therefor, and the process and apparatus are a process for manufacturing potable water which comprises, a forward osmosis step wherein a liquid of which solvent is water is allowed to contact with a draw solution produced by dissolving a prescribed amount of a volatile material in water through a semi-permeable membrane, and water in said liquid is allowed to migrate to said draw solution through said semi-permeable membrane, a distillation step wherein a dilute draw solution having been diluted with water which was produced in said step is adjusted to a prescribed temperature, and then is delivered to a distillation column where gas comprising the volatile material and water vapor is discharged from the top of the column and potable water is discharged from the bottom of the column, and a cooling • regeneration step wherein said draw solution is regenerated by cooling said gas and an apparatus therefor.

The invention discloses a method and an apparatus for treatment of a concentrated reverse osmosis drainage through coupled forward osmosis and reverse osmosis. The method comprises the following steps that: a raw forward osmosis solution directly enters into a forward osmosis assembly, a concentrated reverse osmosis drainage is used as a driving solution for forward osmosis, water of the raw forward osmosis solution permeates a membrane, the concentrated reverse osmosis drain is diluted and then mixed with raw reverse osmosis water, then flows through a high-pressure pump and enters into a reverse osmosis assembly as inflowing reverse osmosis water, water penetrating to one side of the driving solution from the raw forward osmosis solution is recycled through reverse osmosis, and the concentrated reverse osmosis drainage is circulated as the driving solution for forward osmosis. The apparatus comprises a first feed pump, a second feed pump, the forward osmosis assembly, the high-pressure pump and the reverse osmosis assembly. According to the invention, the utilization rate of the concentrated reverse osmosis drain can be increased; pollution of the concentrated reverse osmosis drainage to the environment can be reduced; the method and the apparatus can also be used for liquid concentration and desalination, producing significant economic values; and the apparatus provided by the invention has the advantages of a small occupied land area, a compact structure, simple operation, low running cost and low energy consumption.

The invention discloses a preparation method of a layer-by-layer self-assembled hollow fiber forward osmosis membrane. The preparation method comprises the steps of: preparing hollow fiber forward osmosis base film, modifying hollow fiber ultrafiltration base film, repeating layer-by-layer assembly of polycation and polyanion layers, performing interface cross-linking polymerization for preparinga selective functional layer, conducting moisturizing, and carrying out treatment and storage so as to prepare the layer-by-layer self-assembled hollow fiber forward osmosis membrane. The surface of the hollow fiber self-support base film which is prepared by using a phase conversion method is activated firstly, layer-by-layer assembly of polycation and polyanion is repeated on the surface of thefilm so as to form an functional polarization layer for an electrolyte solution, and the polyamide selective layer is prepared through interfacial chemical cross-linking polymerization. The prepared hollow fiber forward osmosis membrane has a controllable thickness and an internal polarization layer with a high charge capacity, and the internal concentration polarization phenomenon can be alleviated effectively during the forward osmosis process; therefore, the hollow fiber forward osmosis membrane can simultaneously obtain high flux and low reverse salt flux, has high filtration separation efficiency, easy cleaning and a long service life, and can be widely applied to seawater desalination and concentration and desalination of brine.

Methods and systems for generating strong brines are disclosed in which a feed stream and a draw inlet stream are passed through a forward osmosis membrane to create a concentrate and a draw outlet stream, the draw outlet stream is passed through a reverse osmosis membrane to create a reverse osmosis permeate flow and a reverse osmosis retentate flow, the reverse osmosis retentate flow is passed through a first nanofiltration membrane to create a first nanofiltration permeate flow and a first nanofiltration retentate flow; and the first nanofiltration retentate flow is passed through a second nanofiltration membrane to create a second nanofiltration permeate flow and a second nanofiltration retentate flow. In some embodiments, the process is repeated through a third nanofiltration membrane. The process may be repeated through a third nanofiltration membrane.

Forward osmosis methods and apparatus using a controllable osmotic agent to establish or enhance an osmotic forward bias are disclosed. In a conventional osmosis environment, a controllable osmotic agent is selectively added to an effluent to establish or enhance an osmotic imbalance that favors transfer of an influent solvent to the effluent. After desirable transfer of the influent solvent to the effluent, the controllable osmotic agent is isolated, removed or neutralized so that the transferred solvent and / or concentrated influent can be recovered. The controllable osmotic agent comprises a composition that is reactive to an external influence that does not appreciably affect the effluent solvent, for example, magnetic forces, electrical charges and filtration. Batch and continuous process methods and apparatus are also disclosed.

Periodically operating a forward osmosis (FO) semi-permeable membrane element in reverse osmosis (RO), to yield product extraction on a feed side of the membrane, to flush out a concentration polarization (salt concentration of the feed side and dilution of draw solution on the draw side) across the membrane. Utilizing treated waste water to generate the flushing solution of low osmotic pressure, and gauge pressurizing the flushing solution to the gauge pressure of the draw solution to keep a constant gauge pressure of the solutions. FO process is interrupted every 5-20 minutes for a 10-60 seconds long flushing RO process, thereby increasing the FO throughput five fold and recovering power from the increased throughput, i.e. from the osmotic pressure of the brine.

The invention provides a method for preparing a nano-material-doped polymer film, and relates to the method for preparing polymer film, mainly solving the technical matters that nanometer materials in the nano-material-doped polymer film prepared by an existing method are uneven and easy to fall off, and an additional pore-forming agent is required for the nano-material-doped polymer film. The method comprises the steps of: performing hydrophilic process and organic process on the nanometer materials; dispersing the processed nanometer materials into an organic solvent to obtain a suspending liquid; adding a polymer into the suspending liquid; sealing; and heating and agitating to obtain a filming liquid; processing the filming liquid on a flat plate by curtain coating way to form liquid film; dipping the liquid film into a coagulating bath to undergo exchange between solvent and non-solvent so as to achieve phase transformation; and dipping the solidified film fallen from the flat plate into deionized water to obtain the nano-material-doped polymer film. The nano-material-doped polymer film provided by the invention can be prepared into micro-filtration film, ultra-filtration film, nano-filtration film, reverse osmosis film, and forward osmosis film, as well as flat film, tubular film or hollow fiber film and related film subassemblies. The nano-material-doped polymer film can be applied to the field of water treatment and chemical engineering separation.

This disclosure describes draw solution compositions for FO processes which increase the available membrane area for permeation and are also amenable to reconcentration with standard techniques, such as membrane filtration and evaporative technologies. The composition are comprised of a water soluble draw solute having surface active properties, i.e., a surfactant.

A membrane structure suitable for use in forward osmosis processes, which membrane structure is comprised of a support membrane comprised of ultra high molecular weight polyethylene and having an active surface which active surface contains a cellulosic coating.

The invention provides a preparation method and application of a separation film with a nano composite cortical layer. The separation film comprises a non-woven fabric layer, two porous support layers and a desalination layer, and is characterized in that the lower layer of the two porous support layers is a porous body layer containing polymers and / or nano particles, and the upper layer of the two porous support layers is a porous cortical containing polymers and nano particles. The preparation method includes coating the upper layer and the lower layer of the non-woven base material by means of a double-layer coating technology. An ultrafilter support layer of the composite separation film prepared by the preparation method is good in surface evenness, hight water flux is kept in the meantime of keeping higher cutoff rate, and the separation film can be directly used as an ultrafiltration film or can be used as a basic porous support layer to further prepare a composite forward osmosis, reverse osmosis and nanofiltration film. The preparation method can be applied to preparing the reverse osmosis film and the nanofiltration film which are good in performance, and a composite ultrafiltration film with low molecular weight cutoff.

The invention discloses a high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane, which is prepared by comprising the following steps: adding the following raw materials in percentage by weight: 7.0%-26.0% of cellulose acetate, 2.0%-16.0% of additives, 0.1%-5.0% of nano-titanium dioxide, 0.05%-0.1% of graphene, and a dimethylformamide or dimethylacetamide, N-methylpyrrolidine and acetone mixed solvent into a dissolving tank according to certain sequence, stirring and dissolving for 3-15h to be full and even at 25-90DEG C, thus obtaining blended forward osmosis membrane casting liquid; and preparing the high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane on a supporting material by using a phase conversion method. According to the prepared forward osmosis membrane, 1M NaCl and deionized water are respectively taken as driving liquid and feed solution, the flux of pure water can reach more than 17.5L / m<2>.h during testing time of1h and the backward salt flux is less than 3.0g / m<2>.h.