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.

Methods of employing peroxycarboxylic acid compositions for the prevention of scale formation and in some embodiments the removal of existing scale are disclosed. In particular, the scale inhibition properties of percarboxylic acids of varying chain lengths including C1-C22 provide effective scale inhibition and scale removal or destruction. Methods of employing peroxycarboxylic acid compositions for scale inhibition and/or removal are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. The methods provide suitable scale inhibition replacements and/or additives to known scale inhibitors.

Methods of employing peroxycarboxylic acid compositions for the prevention of scale formation and in some embodiments the removal of existing scale are disclosed. In particular, the scale inhibition properties of percarboxylic acids of varying chain lengths including C1-C22 provide effective scale inhibition and scale removal or destruction. Methods of employing peroxycarboxylic acid compositions for scale inhibition and/or removal are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. The methods provide suitable scale inhibition replacements and/or additives to known scale inhibitors.

A system and method for generating base water and precipitate, including combining produced water with seawater to precipitate barium sulfate from barium in the produced water and from sulfate in the seawater, and separating the precipitate to give the base water and the precipitate. The base water may have less than a specified amount of sulfate and be utilized for hydraulic fracturing fluid. The precipitate may give a weighting agent for drilling.

A system and method for generating base water and precipitate, including combining produced water with seawater to precipitate barium sulfate from barium in the produced water and from sulfate in the seawater, and separating the precipitate to give the base water and the precipitate. The base water may have less than a specified amount of sulfate and be utilized for hydraulic fracturing fluid. The precipitate may give a weighting agent for drilling.

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.

This invention provides processes for treating a mixture of produced water and blowdown water comprising introducing produced water (PW) into blowdown water (BD) for forming a PW-BD water mixture, softening the PW-BD water mixture, subjecting the PW-BD water mixture to activated carbon filtration and reverse osmosis membrane desalination. The process generates a product water and a brine by-product.

This invention provides processes for treating a mixture of produced water and blowdown water comprising introducing produced water (PW) into blowdown water (BD) for forming a PW-BD water mixture, softening the PW-BD water mixture, subjecting the PW-BD water mixture to activated carbon filtration and reverse osmosis membrane desalination. The process generates a product water and a brine by-product.

Provided are water treatment systems for reducing hardness in water. The water treatment systems include an electrodialysis device comprising a brine inlet stream, a feed stream, a brine outlet stream, and a product outlet stream, and a template assisted crystallization (TAC) filter comprising a brine inlet stream and a brine outlet stream. The brine inlet stream comprises the brine outlet stream of the electrodialysis device and the brine inlet stream of the electrodialysis device comprises the brine outlet stream of the TAC filter. The system pressure is reduced by 30-60% when the brine stream goes through a TAC filter than a system without the filter. An acid supply and an acid feed stream may also be included, wherein the brine inlet stream of the electrodialysis device comprises the brine outlet stream of the TAC filter and the acid feed stream.

Provided are water treatment systems for reducing hardness in water. The water treatment systems include an electrodialysis device comprising a brine inlet stream, a feed stream, a brine outlet stream, and a product outlet stream, and a template assisted crystallization (TAC) filter comprising a brine inlet stream and a brine outlet stream. The brine inlet stream comprises the brine outlet stream of the electrodialysis device and the brine inlet stream of the electrodialysis device comprises the brine outlet stream of the TAC filter. The system pressure is reduced by 30-60% when the brine stream goes through a TAC filter than a system without the filter. An acid supply and an acid feed stream may also be included, wherein the brine inlet stream of the electrodialysis device comprises the brine outlet stream of the TAC filter and the acid feed stream.