According to one or more embodiments, sulfate ions may be removed from seawater to form an injection fluid by a method including passing the seawater and formation water to a mixing tank. The seawater may comprise sulfate ions. The formation water may comprise barium ions. The seawater and formation water may be passed to the mixing tank in a ratio determined by a computerized geochemical model. The method may further include mixing the seawater and formation water to form a mixed fluid and passing the mixed fluid to a clarifier, where a barium sulfate precipitate may be formed and at least a portion of the barium sulfate precipitate may be separated from the mixed fluid. The method may further include passing the mixed fluid to a microfiltration system, where at least a portion of the barium sulfate precipitate may be removed from the mixed fluid to form an injection fluid.

A water heater system includes a water heater rack system with a plurality of vertically stacked tankless water heaters and a water heater storage tank and provides the ability to install a water heater in environments where horizontally oriented heater rack systems would not fit. The tankless water heaters comprise a bifurcated vent arrangement with separate intake and exhaust vents. Accordingly, vent pipes of diameters of two (2) inches or less may be used in comparison to coaxial vent arrangements which may have diameters of three inches or more. The smaller vent pipe diameter allows a plurality of water heaters to be stacked, one above the other, such that the water heater rack system has a maximum height of 76 inches or less. This vertical orientation may allow tankless water heaters to be installed in an environment where a horizontally configured plurality of tankless water heaters would not fit.

A system for water rejuvenation for the regeneration of sorbent filters is disclosed. The system includes an anion reduction subsystem having a plurality of anionic exchange resin beds configured to remove impurity anions from a wash water used in a moisture-swing, direct-air-capture device. Each resin beds is in a vessel inside of which is configured to perform at least one of three operations: (1) conditioning resin beds by flushing them with carbonate or bicarbonate, (2) upgrading the wash water by removing impurity anions from the wash water reservoir, and (3) cleaning input water by exchanging impurity anions for carbonate or bicarbonate ions in the input feed. Each vessel cycles through these operations in the order (1), (2), (3). The system also includes a cation reduction subsystem that reduces the salinity of the wash water, and a divalent reduction subsystem that softens the wash water by removing divalent ions.

A system for water rejuvenation for the regeneration of sorbent filters is disclosed. The system includes an anion reduction subsystem having a plurality of anionic exchange resin beds configured to remove impurity anions from a wash water used in a moisture-swing, direct-air-capture device. Each resin beds is in a vessel inside of which is configured to perform at least one of three operations: (1) conditioning resin beds by flushing them with carbonate or bicarbonate, (2) upgrading the wash water by removing impurity anions from the wash water reservoir, and (3) cleaning input water by exchanging impurity anions for carbonate or bicarbonate ions in the input feed. Each vessel cycles through these operations in the order (1), (2), (3). The system also includes a cation reduction subsystem that reduces the salinity of the wash water, and a divalent reduction subsystem that softens the wash water by removing divalent ions.

As pellets grow from seed/sand in a fluidized bed pellent reactor, the weight of the reactor is measured and the density of the contents of the reactor is calculated, and the input flow of untreated water, water treatement chemical, and seed/sand are adjusted to provide improved removal of water hardness while reducing fine particulates in the outflow of softened water from the reactor.

As pellets grow from seed/sand in a fluidized bed pellent reactor, the weight of the reactor is measured and the density of the contents of the reactor is calculated, and the input flow of untreated water, water treatement chemical, and seed/sand are adjusted to provide improved removal of water hardness while reducing fine particulates in the outflow of softened water from the reactor.

A method for removing calcium ions from high concentration organic wastewater is provided. The method comprises the steps of: (1) introducing high concentration organic wastewater containing Ca.sup.2+, inorganic carbon and a seed crystal into a reactor with a molar ratio of Ca.sup.2+ to inorganic carbon of 1:(3.2-6.2); (2) adjusting the hydrogen ion activity α(H.sup.+) and ionic strength of the solution in the reactor; (3) sequentially stirring and precipitating in the reactor to convert Ca.sup.2+ in the high concentration organic wastewater into calcium carbonate which is then precipitated for calcium removal.

A method for removing calcium ions from high concentration organic wastewater is provided. The method comprises the steps of: (1) introducing high concentration organic wastewater containing Ca.sup.2+, inorganic carbon and a seed crystal into a reactor with a molar ratio of Ca.sup.2+ to inorganic carbon of 1:(3.2-6.2); (2) adjusting the hydrogen ion activity α(H.sup.+) and ionic strength of the solution in the reactor; (3) sequentially stirring and precipitating in the reactor to convert Ca.sup.2+ in the high concentration organic wastewater into calcium carbonate which is then precipitated for calcium removal.

The invention generally relates to methods of removing potassium, rubidium, and/or cesium, selectively or in combination, from brines using tetrafluoroborates. Also disclosed are methods of producing potassium, rubidium, and/or cesium chlorides using ionic liquids and exchange media. This invention also generally relates to treated geothermal brine compositions containing reduced concentrations of silica, iron, and potassium compared to the untreated brines. Exemplary compositions of the treated brine contain a concentration of silica ranging from about 0 mg/kg to about 15 mg/kg, a concentration of iron ranging from about 0 mg/kg to about 10 mg/kg, and a concentration of potassium ranging from about 300 mg/kg to about 8500 mg/kg. Other exemplary compositions of the treated brines also contain reduced concentrations of elements like rubidium, cesium, and lithium.

An ion-exchange resin regeneration system includes: salt water flowing means that flows an aqueous sodium chloride solution or an aqueous potassium chloride solution into a container storing ion-exchange resin; and hard water component crystallizing means that crystallizes and removes hard water components containing metal ions from drained water arising from the ion-exchange resin through which the aqueous sodium chloride solution or the aqueous potassium chloride solution has flowed.