Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

An electrochemical system has a first reservoir receiving a feed stream. The feed stream includes a solvent and a solute different than the salt. A second reservoir receives a brine stream with a higher salt concentration higher than the feed stream. Electrodes contact a loop of redox- active electrolyte material causing reversible redox reactions. The reactions cause the loop to accept a first ion from the salt in the first reservoir and drive a second ion into the brine stream in the second reservoir. Three ionic exchange membranes of alternating type define the first and second reservoirs. A concentrate stream is output from the first reservoir, the concentrate stream having a second solute concentration greater than the first solute concentration.

An electrochemical system has a first reservoir receiving a feed stream. The feed stream includes a solvent and a solute different than the salt. A second reservoir receives a brine stream with a higher salt concentration higher than the feed stream. Electrodes contact a loop of redox- active electrolyte material causing reversible redox reactions. The reactions cause the loop to accept a first ion from the salt in the first reservoir and drive a second ion into the brine stream in the second reservoir. Three ionic exchange membranes of alternating type define the first and second reservoirs. A concentrate stream is output from the first reservoir, the concentrate stream having a second solute concentration greater than the first solute concentration.

A device for delivering an ionic material includes a storage module including a reservoir configured to store the ionic material, a bipolar membrane configured to pass the ionic material in a single direction based on an ionic current, electrodes, disposed on a lower end of the reservoir and an upper end of the bipolar membrane, respectively, configured to form an electric field generating the ionic current, and a control module configured to control either one or both of a release amount and a release period of the ionic material passing through the bipolar membrane by adjusting a direction and an intensity of the electric field.

A wastewater treatment method includes: a soft water treatment 1 of crystallizing calcium carbonate from wastewater to remove the calcium carbonate therefrom; and an electrolysis 2 of electrolyzing some of the wastewater from which the calcium carbonate has been removed to obtain an acidic aqueous solution and an alkaline aqueous solution, wherein at least some of the alkaline aqueous solution is circulated to be used in the soft water treatment 1.

A wastewater treatment method includes: a soft water treatment 1 of crystallizing calcium carbonate from wastewater to remove the calcium carbonate therefrom; and an electrolysis 2 of electrolyzing some of the wastewater from which the calcium carbonate has been removed to obtain an acidic aqueous solution and an alkaline aqueous solution, wherein at least some of the alkaline aqueous solution is circulated to be used in the soft water treatment 1.

The present application relates to a preparation method for recycling inorganic salt in printing and dyeing wastewater and comprises the following process steps: S1, performing impurity removal, softening, COD removal and decoloration on reverse osmosis (RO) membrane concentrated water to obtain pretreated wastewater; S2, performing two-stage electrodialysis on the wastewater obtained in step S1: returning fresh water obtained in a first-stage electrodialysis desalination chamber to a front end of the RO process, and taking saline water obtained in a concentration chamber as raw water of a second-stage electrodialysis desalination chamber and a second-stage electrodialysis concentration chamber; and returning the fresh water obtained by the second-stage electrodialysis desalination chamber to the first-stage electrodialysis concentration chamber; and S3, dealkalizing the concentrated saline water obtained in the step S2 and then adjusting the pH value to obtain concentrated saline water capable of being reused for cloth dyeing in a printing and dyeing mill.

A composite ion exchange membrane comprising components (a) and (b): (a) a membrane layer comprising ionic groups, two opposing surfaces and optionally a porous support; (b) a layer comprising sulpho groups bound to at least one of the at least two opposing surfaces of the membrane layer (a);
wherein the layer comprising sulpho groups has a thickness of less than 100 nm and the composite ion exchange membrane has a surface zeta potential of 0 to −7.5 mV.

Systems and methods for at least partially removing carbon dioxide (CO.sub.2) from a feed gas comprising CO.sub.2 are generally provided.

An ion permeable membrane for selective permeation of a target ion, preferably lithium, through the membrane, the membrane comprising a target ion permeable composite comprises a target ion permeable ceramic and at least one organic polymer associated with the target ion permeable ceramic.