# US 2014/0197112 A1 · Potabilisation method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197112 A1 - Document ID: US20140197112A1 - Status: Published application - Kind: A1 - Application number: 14/234,238 - Filed: 2012-07-19 - Published: 2014-07-17 - Earliest claimed: 2011-07-22 - Assignees: Roquette Freres - Inventors: Laura Crowther-Alwyn - Web page: https://patentgrep.com/patent/US20140197112A1 ## CPC - C02F 1/5236: {using inorganic agents} - C02F 1/5245: {using basic salts, e.g. of aluminium and iron} - C02F 1/5272: {using specific organic precipitants} - C02F 1/001: {Processes for the treatment of water whereby the filtration technique is of importance (C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00)} - C02F 1/24: by flotation (C02F1/465 takes precedence) - C02F 2209/09: Viscosity - C02F 2209/11: Turbidity - 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) ## Abstract A potabilisation method of a water to be treated, containing a coagulation-flocculation step wherein the step includes: a) a step of adding a liquid composition including a solubilized cationic starch to the aqueous solution to be treated; b) a step of adding one or several metal salts selected from ferric salts and aluminum salts to the aqueous solution to be treated; steps a) and b) being carried out in any order and being carried out either separately, simultaneously or using a liquid composition including both the solubilized cationic starch and the metal salt, the steps a) and b) being followed: c) by a step of stirring the supplemented aqueous solution; d) by a step of separating the coagulated solids by sedimentation or floatation; e) by a step of recovering a purified water; the liquid composition including cationic starch having a viscosity, measured according to test A, higher than 1000 mPa·s. ## Claims ### Claim 1 A method of potabilization of an aqueous solution having solids in suspension, containing a coagulation-flocculation step, characterized in that said step comprises: a) a step of adding a liquid composition comprising a solubilized cationic starch to the aqueous solution to be treated; b) a step of adding one or more metal salts selected from ferric salts and aluminum salts to the aqueous solution to be treated; steps a) and b) being carried out in any order and they can be effected separately, simultaneously or by means of a liquid composition comprising both the solubilized cationic starch and the metal salt, said steps a) and b) being followed by: c) a step of stirring the aqueous solution containing these additives; d) a step of separating the coagulated solids by decanting or flotation; e) a step of recovering purified water; said liquid composition comprising cationic starch having a viscosity, measured according to a test A, above 1000 mPa·s, this test A consisting of adjusting the dry matter of the liquid composition to 10% and then measuring the Brookfield viscosity of the resultant composition at 25° C. ### Claim 2 (depends on 1) The method as claimed in claim 1, characterized in that the viscosity of the liquid composition comprising cationic starch, measured according to test A, is between 1100 and 500000 mPa·s. ### Claim 3 (depends on 1) The method as claimed in claim 1, characterized in that the viscosity of the liquid composition comprising cationic starch, measured according to test A, is between 10000 and 100000 mPa·s. ### Claim 4 (depends on 1) The method as claimed in claim 1, characterized in that the time delay between steps a) and b) is less than 120 seconds. ### Claim 5 (depends on 1) The method as claimed in claim 1, characterized in that steps a) and b) are carried out simultaneously. ### Claim 6 (depends on 1) The method as claimed in claim 1, characterized in that the total amount of cationic starch and of metal salt in the aqueous solution ranges from 4 to 500 ppm, preferably from 5 to 10 ppm. ### Claim 7 (depends on 1) The method as claimed in claim 1, characterized in that the cationic starch/metal salt weight ratio ranges from 15/85 to 70/30, preferably from 25/75 to 45/55. ### Claim 8 (depends on 1) The method as claimed in claim 1, characterized in that the separation step d) is a decanting step. ### Claim 9 (depends on 1) The method as claimed in claim 1, characterized in that it comprises, after the coagulation-flocculation step, a step of filtration of the purified water. ### Claim 10 (depends on 1) The method as claimed in claim 1, characterized in that the turbidity of the purified water obtained at the end of step e) is less than or equal to 1.5 NTU, preferably below 1 NTU. ### Claim 11 (depends on 1) A liquid composition suitable for use in the method as claimed in claim 1, comprising a solubilized cationic starch and or more metal salts selected from ferric salts and aluminum salts, whose viscosity, measured according to test A, is above 1000 mPa·s. ### Claim 12 (depends on 11) The composition as claimed in claim 11, characterized in that the viscosity of the liquid composition comprising cationic starch, measured according to test A, is between 10000 and 100000 mPa·s. ### Claim 13 (depends on 11) The composition as claimed in claim 11, characterized in that the metal salt is an aluminum salt. ### Claim 14 (depends on 11) The composition as claimed in claim 11, characterized in that the cationic starch/metal salt weight ratio ranges from 15/85 to 70/30, preferably from 25/75 to 45/55. ### Claim 15 (depends on 11) The composition as claimed in claim 11, characterized in that it has a pH between 3 and 7.