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.

A desalination battery cell includes a first compartment separated by an anion exchange membrane from a second compartment, each of the first and second compartments containing a saline water solution having a concentration of dissolved salts c.sub.1 and first and second intercalation host electrodes, respectively, in fluid communication with the solution, a voltage source supplying electric current to the first and second intercalation host electrodes to release cations into the solution, and a controller programmed to adjust an amount of the electric current being supplied to change direction of anions in the solution passing through the anion exchange membrane between the compartments such that the first and second compartments alternately collect and disperse salt from the solution and release desalinated water solution having a concentration c.sub.2 of dissolved salts and a brine solution having a concentration c.sub.3 of dissolved salts such that c.sub.3>C.sub.1>C.sub.2.

Disclosed is a hybrid water-treating system. The system includes a raw-water supply bath having a predetermined volume and configured to receive raw-water containing high concentration organic contaminants; at least one electrolytic bath configured to receive the raw-water supplied from the raw-water supply bath and to produce first treated water, wherein a boron doped diamond (BDD) electrode is installed in the electrolytic bath; and at least one deionization bath configured to receive the first treated water discharged from the electrolytic bath and to produce second treated water, wherein flow-electrode capacitive deionization (FCDI) is performed when applying a first voltage to the deionization bath.

The present disclosure describes a flow-electrode capacitive deionization (FCDI) desalination system and method of use. The system employs clusters of tubular membranes oriented parallel to each other, each membrane having an internal flow path capable of receiving an electrolyte slurry (carbon slurry) therethrough. Each tubular membrane further comprises an electrode coaxially extending through the entire length of the electrode. Preferably, adjacent electrodes within the cluster receive a positive or negative charge, respectively. The cluster of tubular membranes is nested within a flow chamber capable of receiving saline or brackish water to be flowed along the outside surfaces of the tubular membranes to cause selected ions, e.g., Na+, Cl to pass through the membranes and into the carbon slurry circuit. The desalinated water then passes out of the flow chamber. The outer diameter of the electrodes can be optimized based on the inner diameter of the tubular membrane.

The present invention relates to a desalination apparatus and a desalination method using the same. In one specific embodiment, the desalination apparatus comprises: a forward osmosis unit having a draw-solution part into which seawater flows, and a raw water part into which raw water flows, and having an osmosis membrane, formed between the draw solution part and the raw water part, so as to respectively generate first treated water and first concentrated water; a capacitive deionization unit, which is connected to the draw solution part through a first inflow passage, and into which the first treated water of the draw solution part flows so as to generate second treated water; and an electrodialysis unit, which is connected to the raw water part through a second inflow passage, and into which the first concentrated water of the raw water part flows so as to generate third treated water.

The present invention relates to a single module, flow-electrode apparatus for continuous water desalination, ion separation and selective ion removal and concentration by capacitive deionization, comprising: a first current collector (1), a first compartment (1) for a flow electrode, a first ion exchange membrane (AEM, CEM), a first liquid-permeable channel (6a) next to the first ion exchange membrane (AEM, CEM), a second ion exchange membrane (CEM, AEM) with a fixed charge opposite to that of the first ion exchange membrane (AEM, CEM) next to the first liquid-permeable channel (6a), a second liquid-permeable channel (6b) next to the second ion exchange membrane (CEM, AEM), a third ion exchange membrane (AEM, CEM) having the same fixed charge as the first ion exchange membrane (AEM, CEM) next to the second liquid-permeable channel (6b), a second compartment (2) for a flow electrode, and a second current collector (2), wherein a fluid (4) containing suspended conductive particles or a mixture of conductive and non-conductive particles or particles made of a mixture of conductive and non-conductive materials (5) is provided in the first and second compartments (1, 2), acting as the flow electrode, as well as a corresponding method.

A fluid purification system has cells whose purifying capability can be regenerated. Some of the cells are arranged in series to reach a high level of purification. An automatic valve network is controlled to cycle the cells in a way that levels the loads on each, thereby maximizing the service interval for replacing expired cells, enabling all of the cells to be replaced at the same time after having each contributing approximately equally to the purification load, and operated such that at any one time, at least one cell is regenerated so as to enable continuous up-time.

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.

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.

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.