# US 2021/0276889 A1 · Method for removing a contaminant from wastewater from an industrial plant and a system for performing such method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276889 A1 - Document ID: US20210276889A1 - Status: Published application - Kind: A1 - Application number: 17/274,157 - Filed: 2019-09-17 - Published: 2021-09-09 - Earliest claimed: 2018-09-17 - Assignees: Yara International Asa - Applicants: Yara International Asa - Inventors: Petr CHLADEK; Clive M. H. BRERETON; Eric Robin MIELKE - Web page: https://patentgrep.com/patent/US20210276889A1 ## CPC - C02F 1/445: {by forward osmosis} - C02F 1/44: by dialysis, osmosis or reverse osmosis {(general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268)} - C02F 1/4674: {with halogen or compound of halogens, e.g. chlorine, bromine} - C02F 1/4678: {of metals} - C02F 2101/12: Halogens or halogen-containing compounds - C02F 2103/34: from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 - C02F 2201/461: Electrolysis apparatus - C02F 2301/08: Multistage treatments, e.g. repetition of the same process step under different conditions - 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 The present application relates to a method for removing a contaminant from wastewater from industrial fertilizer plant. The method comprises the steps of concentrating the wastewater, of electrolyzing the wastewater and of recirculating the electrolyzed wastewater to the fertilizer plant. The present application further relates to a system arranged to perform the method according to the present application. ## Claims ### Claim 1 A method for removing a contaminant from wastewater from a fertilizer plant comprising the steps of: a) concentrating the contaminant in the wastewater; b) chemically converting the contaminant in the wastewater by electrolysis; and c) recirculating the electrolyzed wastewater to the industrial plant wherein the step of concentrating the wastewater is performed by a forward osmosis module or a pressure assisted osmosis module, comprising a first compartment and a second compartment separated by a membrane, wherein the step of concentrating the wastewater comprises the step of directing the wastewater to the first compartment of the osmosis module and wherein the recirculating step comprises the steps of i) directing the electrolyzed wastewater to the second compartment of the osmosis module; and ii) recirculating the wastewater from the second compartment of the osmosis module to the fertilizer plant. ### Claim 2 (depends on 1) The method according to claim 1 wherein the contaminant is chloride in particular wherein the chloride concentration of the wastewater after the concentrating step is between 1250 and 2250 ppm. ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 (depends on 1) The method according to claim 1 wherein the flow of the wastewater in the first compartment is counter-current with respect to the flow in the second compartment. ### Claim 6 (depends on 1) The method according to claim 1 further comprising the step of adding a salt solution to or upstream of the second compartment of the osmosis module. ### Claim 7 (depends on 6) The method according to claim 6 wherein the salt solution comprises at least one of ammonium nitrate, ammonium calcium phosphates and calcium nitrate. ### Claim 8 (depends on 1) The method according to claim 1 wherein the fertilizer plant is a nitro-phosphate fertilizer plant, or another mineral or organo-mineral fertilizer plant. ### Claim 9 (depends on 1) The method according to claim 1 wherein the concentration of chloride in the electrolyzed wastewater is less than 350 ppm. ### Claim 10 A system for removing a contaminant from wastewater from an industrial plant comprising: a) a concentrating unit adapted to be fluidly connected to the wastewater from the industrial plant b) an electrochemical treatment unit for removing the contaminant fluidly connected downstream of the concentration unit and adapted to be fluidly connected to recirculate the treated wastewater to the industrial plant, wherein the concentrating unit is a forward or pressure assisted osmosis module, the osmosis module comprising a first compartment and a second compartment separated by a membrane, wherein i) the wastewater from the industrial plant to be treated is fluidly connected to the first compartment; ii) the first compartment is fluidly connected to an inlet of the electrochemical treatment unit; iii) an outlet of the electrochemical treatment unit is fluidly connected to the second compartment and the second compartment is adapted to be fluidly connected to the industrial plant; and optionally iv) a feed of a salt solution fluidly connected to the second compartment; and wherein the electrochemical treatment unit comprises an electrolysis unit. ### Claim 11 (depends on 10) The system according to claim 10 wherein the concentrating unit comprises more than one osmosis module connected in series. ### Claim 12 (depends on 10) The system according to claim 10 wherein the wastewater flow in the first compartment flows counter-currently with respect to the flow of the water in the second compartment. ### Claim 13 (canceled) ### Claim 14 (depends on 2) The method of claim 2 wherein the chloride concentration of the wastewater after the concentrating step is between 1500 and 2250 ppm. ### Claim 15 (depends on 14) The method of claim 14 wherein the chloride concentration of the wastewater after the concentrating step is between 1750 and 2250. ### Claim 16 (depends on 8) The method of claim 8 wherein the fertilizer plant produces compositions comprising ammonium nitrate. ### Claim 17 (depends on 10) The method of claim 10 wherein the second compartment is configured so that wastewater treated in the electrochemical treatment unit can flow though the second compartment and be recirculated to the industrial plant. ### Claim 18 (depends on 11) The system according to claim 11 wherein two or three osmosis modules are connected in series. ### Claim 19 (depends on 1) The method of claim 1 wherein the contaminant forms a gas upon electrolysis.