Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

The present invention relates to a device and to a method for producing dialysate, wherein the device comprises a first part and a second part designed as a circuit, wherein the first part comprises a water connection or a water container and the primary side of a filter, wherein the filter is designed to produce purified water from the water by forward osmosis, and wherein the second part comprises the secondary side of the filter, a reservoir, a filtrate line which leads from the secondary side of the filter to the reservoir, and a return line leading from the reservoir to the secondary side of the filter, wherein an electrodialysis unit comprising a diluate chamber and a concentrate chamber is further provided, wherein the concentrate chamber is fluidically connected to the secondary side of the filter.

A high salinity feed water such as seawater is treated to produce a reverse osmosis (RO) concentrate and an RO permeate. Optionally, some or all of the RO concentrate may be filtered to produce a nanofiltration (NF) permeate. Optionally, some feed water can also be filtered to produce NF permeate without first being concentrated by RO treatment. The NF permeate, or a blend of the RO permeate and NF permeate, may be used to produce a product water for injection into an oil-bearing reservoir to enhance oil recovery. Optionally, the product water may have salinity greater than the feedwater, or at least 30 g/L. The product water may have hardness of less than 20 mg/L.

The present invention relates to an apparatus and a method for preparing dialyzate, wherein the apparatus has a first part and a second part that is configured as a circuit; wherein the first part comprises a water connection or a water container as well as the primary side of a filter; wherein the filter is configured to prepare purified water from the water through forward osmosis; and wherein the second part comprises the secondary side of the filter, a reservoir, a filtrate line that leads from the secondary side of the filter to the reservoir, and a line leading from the reservoir to the secondary side of the filter, with the reservoir being a container having means for connecting the container to a dialysis machine.

A water conditioning system of an electrodialysis reversal (EDR) water purifier includes a first source water inlet, a second source water inlet, an EDR film stack, a first conductive probe, a second conductive probe, a third conductive probe, a fourth conductive probe, a variable speed pump, a one-way valve, a clean water outlet, a waste water outlet, an electrode A, an electrode B, and a control system module. With the four conductive probes detecting conductivity of water flowing through four ports on two sides of the EDR film stack and by sending detected data to the control system module, the control system module adjusts voltages of the electrode A and electrode B accordingly to instantly increase or decrease removal efficiency of the EDR film stack. Thus, the conductivity of the discharged clean water and the quality of the clean water can be stabilized.

A water conditioning system of an electrodialysis reversal (EDR) water purifier includes a first source water inlet, a second source water inlet, an EDR film stack, a first conductive probe, a second conductive probe, a third conductive probe, a fourth conductive probe, a variable speed pump, a one-way valve, a clean water outlet, a waste water outlet, an electrode A, an electrode B, and a control system module. With the four conductive probes detecting conductivity of water flowing through four ports on two sides of the EDR film stack and by sending detected data to the control system module, the control system module adjusts voltages of the electrode A and electrode B accordingly to instantly increase or decrease removal efficiency of the EDR film stack. Thus, the conductivity of the discharged clean water and the quality of the clean water can be stabilized.

A composite semipermeable membrane 12 of the present invention includes a porous support membrane 12a and a skin layer 12b supported by the porous support membrane 12a. The membrane surface of the composite semipermeable membrane 12 has an elastic modulus of 250 MPa or more and 500 MPa or less as calculated by force curve measurement using AFM in water. A spiral membrane element 20 of the present invention includes the composite semipermeable membrane 12 of the present invention. A water treatment system 100 of the present invention includes the spiral membrane element 20 of the present invention.

A wastewater treatment equipment and a treatment method of a wastewater are provided. The wastewater treatment equipment includes: a microfiltration unit, configured to receive and filter a wastewater to obtain a solution; a membrane salt separation unit, configured to receive the solution and separate monovalent ions and multivalent ions from the solution to obtain a first solution including the monovalent ions and a second solution including the multivalent ions; a first evaporative crystallization unit, configured to crystallize the first solution to form a monovalent salt; and a second evaporative crystallization unit, configured to crystallize the second solution to form a mixed salt; the microfiltration unit is connected to the membrane salt separation unit, and the first evaporative crystallization unit and the second evaporative crystallization unit are both directly connected to the membrane salt separation unit, the wastewater treatment equipment can achieve the standard discharge of wastewater.

A method includes supplying a supersaturated brine stream having a plurality of minerals and anti-scalant from a water treatment system to a gypsum removal system disposed within a mineral removal system. The gypsum removal system includes a gypsum reactor that may receive the supersaturated brine, may deactivate the anti-scalant such that gypsum precipitates from the supersaturated brine, and may generate a gypsum slurry having a mixture of desupersaturated brine, precipitated gypsum, and the anti-scalant in solution with the desupersaturated brine. The method also includes supplying gypsum seed crystals to the gypsum reactor. The gypsum seed crystals may precipitate the gypsum from the supersaturated brine to generate the gypsum slurry. The method also includes directing a first portion of the gypsum slurry from the gypsum reactor to a gypsum settler. The gypsum settler may reactivate the anti-scalant such that the anti-scalant absorbs onto the precipitated gypsum to remove the anti-scalant from the desupersaturated brine and may generate anti-scalant-gypsum crystals and a desupersaturated overflow having at least a portion of the plurality of minerals. The method further includes generating the gypsum seed crystals supplied to the gypsum reactor using the anti-scalant-gypsum crystals.

A method includes supplying a supersaturated brine stream having a plurality of minerals and anti-scalant from a water treatment system to a gypsum removal system disposed within a mineral removal system. The gypsum removal system includes a gypsum reactor that may receive the supersaturated brine, may deactivate the anti-scalant such that gypsum precipitates from the supersaturated brine, and may generate a gypsum slurry having a mixture of desupersaturated brine, precipitated gypsum, and the anti-scalant in solution with the desupersaturated brine. The method also includes supplying gypsum seed crystals to the gypsum reactor. The gypsum seed crystals may precipitate the gypsum from the supersaturated brine to generate the gypsum slurry. The method also includes directing a first portion of the gypsum slurry from the gypsum reactor to a gypsum settler. The gypsum settler may reactivate the anti-scalant such that the anti-scalant absorbs onto the precipitated gypsum to remove the anti-scalant from the desupersaturated brine and may generate anti-scalant-gypsum crystals and a desupersaturated overflow having at least a portion of the plurality of minerals. The method further includes generating the gypsum seed crystals supplied to the gypsum reactor using the anti-scalant-gypsum crystals.