A composition for treating swimming pool water comprises sodium bisulphate and aluminium sulphate. The aluminium sulphate in the composition minimizes the precipitation of sodium bisulphate at temperatures lower than about 5 degrees Celsius for a time period to maintain a concentrated form of acid to control the pH level of the water. In some embodiments, the composition includes 30 to 40% sodium bisulphate (NaHSO4) wt/wt %, 0.2% to 5% aluminium sulphate Al2(SO4)3 wt/wt %, 0.1% to 1% copper sulphate/chelating agent wt/wt %, 0.01% to 0.02% sodium hydroxide, and balance water.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A system and method for treating reverse-osmosis (RO) concentrated water with high temporary hardness. The system includes a crystallization unit, a precipitation unit, a dewatering unit, and a programmable logic controller (PLC) system. The crystallization unit, precipitation unit and dewatering unit are connected in series, and the PLC system is configured to control pumps, valves, and displays in the crystallization unit, precipitation unit and dewatering unit. The crystallization unit includes a storage tank and a crystallization reactor communicated therewith. The crystallization reactor is provided with a pH meter, a liquid-level gauge, and a stirrer. A connection pipe between the crystallization reactor and the RO concentrated water is provided with an inlet pump and a inlet valve. A connection pipe between the crystallization reactor and the storage tank is provided with a feeding pump and a feeding valve.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

The present disclosure relates to the treatment of produced water from SAGD operations or other thermal in situ hydrocarbon recovery operations. The innovative products and techniques have been developed by Baymag Inc, a subsidiary of Refratechnik Holding GmbH. For example, the disclosure relates to a silica reducer composition for use in warm or hot lime softeners or evaporators for treating produced water generated from in situ hydrocarbon recovery operations. The silica reducer composition has an enhanced combination of particle sizing and surface area for facilitating silica reduction while minimizing hydration. The silica reducer composition can be manufactured by calcining followed by milling and other optional process steps.

The present disclosure relates to the treatment of produced water from SAGD operations or other thermal in situ hydrocarbon recovery operations. The innovative products and techniques have been developed by Baymag Inc, a subsidiary of Refratechnik Holding GmbH. For example, the disclosure relates to a silica reducer composition for use in warm or hot lime softeners or evaporators for treating produced water generated from in situ hydrocarbon recovery operations. The silica reducer composition has an enhanced combination of particle sizing and surface area for facilitating silica reduction while minimizing hydration. The silica reducer composition can be manufactured by calcining followed by milling and other optional process steps.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water is concentrated in a reverse osmosis step and salt from the resulting solution is removed in supercritical conditions prior to destruction of PFAS in supercritical conditions.

The present disclosure relates to methods of treating water to remove contaminants, including harmful metal ions, and water treatment plants for practicing such methods. In an embodiment, the process includes adding a sulfur-containing, metal-decreasing agent; an iron (III)-containing, metalloid-decreasing agent; forming a solid precipitate from the contaminated water, wherein the solid precipitate includes a solid metal sulfide, a solid iron metalloid, a solid calcium metalloid, or a combination thereof; and separating the contaminated water from the solid precipitate to form purified water.