# US 5,700,377 A · Purification of water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,377 A - Document ID: US5700377A - Status: Granted - Kind: A - Application number: 08/668,966 - Filed: 1996-06-18 - Granted: 1997-12-23 - Earliest claimed: 1996-06-18 - Inventors: Peter Glen Cox - Web page: https://patentgrep.com/patent/US5700377A ## CPC - C02F 1/50: by addition or application of a germicide or by oligodynamic treatment {(C02F1/4606, C02F1/467, C02F1/76 take precedence)} - C02F 1/722: {Oxidation by peroxides} - C02F 2103/42: from bathing facilities, e.g. swimming pools - Y10S 210/912: Heavy metal - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A chemical composition for use in purifying water used in swimming pools having surfaces that are comprised of materials that do not react with or dissolve in water, comprising for 2.5 kg of the chemical composition, 1.25 kg of potassiumpersulphate, 300 g of sodium bisulfate, 250 g of ammonium chloride, 100 g of aluminum sulfate, 250 g of sodium bicarbonate, 250 g of calcium chloride and 100 g of ethylendiamine tetra acetic acid (abbreviated EDTA). The potassiumpersulfate and the ammonium chloride are effective in disinfecting water to be purified and in eradicating algae and bacteria therein. The sodium bisulfate, sodium bicarbonate and the calcium chloride are effective in balancing the pH of water to be purified to a pH value within an optimum range between 7.2 and 7.6. The aluminum sulfate serves as a flocculation aid and the copper sulfate is effective in the eradication of black algae. The EDTA is effective to complexing heavy metals in the water. ## Claims ### Claim 1 A chemical composition for the purification of water for use in non-porous swimming pools, which comprises a primary mixture of a peroxide compound in the form of an alkaline persulphate, an acidic compound in the form of sodium bisulphate, an ammonium-based biocidal compound, a basic compound in the form of sodium bicarbonate, a calcium-releasing basic compound and ethylendiamine tetra acetic acid (abbreviated EDTA), the mixture containing 45 to 55% (m/m) alkaline persulphate, 8 to 16% (m/m) sodium bisulphate, 8 to 12% (m/m) ammonium-based biocidal compound, 8 to 12% (m/m) sodium bicarbonate, 8 to 12% (m/m) calcium-releasing basic compound, and 2 to 6% (m/m) EDTA, the alkaline persulphate and the biocidal compound being effective in disinfecting water to be purified and in eradicating algae and bacteria therein, with the sodium bisulphate, the sodium bicarbonate and the calcium-releasing basic compound being effective in balancing the pH of water to be purified to a pH value within an optimum range between 7.2 and 7.6, and the EDTA being effective to complex heavy metals in the water to be purified. ### Claim 2 (depends on 1) A chemical composition as claimed in claim 1, wherein the alkaline persulphate is selected from a group comprising potassiumpersulphate, sodiumpersulphate and ammoniumpersulphate. ### Claim 3 (depends on 1) A chemical composition as claimed in claim 1, wherein the biocidal compound is ammonium chloride. ### Claim 4 (depends on 1) A chemical composition as claimed in claim 1, wherein the calcium-releasing basic compound is calcium chloride. ### Claim 5 (depends on 1) A chemical composition as claimed in claim 1, which includes an effective amount of aluminium sulphate to serve as a flocculation aid. ### Claim 6 (depends on 1) A chemical composition as claimed in claim 1, that comprises 50% (m/m) alkaline persulphate, 12% (m/m) sodium bisulphate, 10% (m/m) ammonium chloride, 4% (m/m) aluminium sulphate, 10% (m/m) sodium bicarbonate, 10% (m/m) calcium chloride, and 4% (m/m) EDTA. ### Claim 7 A kit for the purification of water, for use in non-porous swimming pools, which comprises a primary mixture of a peroxide compound in the form of an alkaline persulphate, an acidic compound in the form of sodium bisulphate, an ammonium-based biocidal compound, a basic compound in the form of sodium bicarbonate, a calcium-releasing basic compound, and ethylendiamine tetra acetic acid (abbreviated EDTA), the mixture containing 45 to 55% (m/m) alkaline persulphate, 8 to 16% (m/m) sodium bisulphate, 8 to 12% (m/m) ammonium-based biocidal compound, 8 to 12% (m/m) sodium bicarbonate, 8 to 12% (m/m) calcium-releasing basic compound, and 2 to 6% (m/m) EDTA, the alkaline persulphate and the biocidal compound being effective in disinfecting water to be purified and in eradicating algae and bacteria therein, with the sodium bisulphate, the sodium bicarbonate and the calcium-releasing basic compound being effective in balancing the pH of water to be purified to a pH value within an optimum range between 7.2 and 7.6, and the EDTA being effective to complex heavy metals in water to be purified. ### Claim 8 (depends on 7) A kit as claimed in claim 7, in which the alkaline persulphate is selected from a group comprising potassiumpersulphate, sodiumpersulphate and ammoniumpersulphate. ### Claim 9 (depends on 7) A kit as claimed in claim 7, wherein the biocidal compound is ammonium chloride. ### Claim 10 (depends on 7) A kit as claimed in claim 7, wherein the calcium-releasing basic compound is calcium chloride. ### Claim 11 (depends on 7) A kit as claimed in claim 7, which includes an effective amount of aluminium sulphate, to serve as a flocculation aid. ### Claim 12 (depends on 7) A kit as claimed in claim 7, which comprises a container containing a chemical composition comprising 50% (m/m) alkaline persulphate, 12%. (m/m) sodium bisulphate, 10% (m/m) ammonium chloride, 10% (m/m) sodium bicarbonate, 10% (m/m) calcium chloride, 4% (m/m) aluminium sulphate, and 4% (m/m) EDTA. ### Claim 13 A method of controlling the purification of water used in non-porous swimming pools, which comprises the steps of: monitoring the pH level of water to be purified; and in the event of the pH level not being in an optimum range between 7.2 and 7.6, adding a predetermined amount of a chemical composition to the water sufficient to adjust the pH level of the water to a pH value within said pH range, the chemical composition comprising a primary mixture of a peroxide compound in the form of an alkaline persulphate, an acidic compound in the form of sodium bisulphate, an ammonium-based biocidal compound, a basic compound in the form of sodium bicarbonate, calcium-releasing basic compound, and ethylendiamine tetra acetic acid (abbreviated EDTA), the mixture containing 45 to 55% (m/m) alkaline persulphate, 8 to 16% (m/m) sodium bisulphate, 8 to 12% (m/m) ammonium-based biocidal compound, 8 to 12% (m/m) sodium bicarbonate, 8 to 12.% (m/m) calcium-releasing basic compound, and 2 to 6% (m/m) EDTA, the alkaline persulphate and the biocidal compound being effective in disinfecting water to be purified and in eradicating algae and bacteria therein, with the sodium bisulphate, the sodium bicarbonate, and the calcium-releasing basic compound being effective to balance the pH of water to be purified to a pH value within an optimum range between 7.2 and 7.6, and the EDTA being effective to complex heavy metals in the water to be purified. ### Claim 14 (depends on 13) A method as claimed in claim 13, wherein the alkaline persulphate of the chemical composition is selected from a group comprising potassiumpersulphate, sodiumpersulphate and ammoniumpersulphate. ### Claim 15 (depends on 13) A method as claimed in claim 13, wherein the biocidal compound is ammonium chloride. ### Claim 16 (depends on 13) A method as claimed in claim 13, wherein the calcium-releasing basic compound is calcium chloride. ### Claim 17 (depends on 13) A method as claimed in claim 13, wherein the chemical composition includes an effective amount of aluminium sulphate to serve as a flocculation aid. ### Claim 18 (depends on 13) A method as claimed in claim 13, wherein the chemical composition comprises 50% (m/m) alkaline persulphate, 12% (m/m) sodium bisulphate, 10% (m/m) ammonium chloride, 10% (m/m) sodium bicarbonate, 10% (m/m) calcium chloride, 4% (m/m) aluminium sulphate and 4% (m/m) EDTA.