# US 9,751,777 B1 · Treatment of produced water from unconventional hydrocarbons exploration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,777 B1 - Document ID: US9751777B1 - Status: Granted - Kind: B1 - Application number: 14/545,681 - Filed: 2015-06-06 - Granted: 2017-09-05 - Earliest claimed: 2011-04-26 - Applicants: Mansour S. Bader - Inventors: Mansour S. Bader - Web page: https://patentgrep.com/patent/US9751777B1 ## CPC - C02F 1/40: Devices for separating or removing fatty or oily substances or similar floating material (cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16) - C02F 9/00: Multistage treatment of water, waste water or sewage - B01D 15/08: Selective adsorption, e.g. chromatography - 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 1/041: {by means of vapour compression} - C02F 1/06: Flash evaporation - C02F 1/441: {by reverse osmosis} - C02F 1/445: {by forward osmosis} - C02F 1/447: {by membrane distillation (distillation and evaporation without the use of membranes C02F1/04)} - C02F 1/5236: {using inorganic agents} - C02F 1/76: with halogens or compounds of halogens {(C02F1/4674 takes precedence)} - C02F 5/02: Softening water by precipitation of the hardness - C02F 2001/5218: {Crystallization} - C02F 2101/006: {Radioactive compounds} - C02F 2101/10: Inorganic compounds - C02F 2101/32: Hydrocarbons, e.g. oil - C02F 2103/10: from quarries or from mining activities - C02F 2103/365: {from petrochemical industry (e.g. refineries)} - C02F 2301/08: Multistage treatments, e.g. repetition of the same process step under different conditions - C02F 2303/22: Eliminating or preventing deposits, scale removal, scale prevention (C02F1/042, C02F1/4602, C02F5/00 take precedence) - 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) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract Unconventional hydrocarbons production from shale and tight-sand formations unlocks vast new energy sources to the nation. However, public perception about excessive potable water use in hydro-fracturing and possible pollution routes in discharging and reusing produced water (flow-back water) promotes state's stringent regulations and opens the door to develop effective produced water treatment methods. This invention is therefore aimed at properly treating produced water to avert health and environmental liabilities and convert economic losses to useful by-products using innovative methods to de-oil, de-scale, and de-salt produced water. ## Claims ### Claim 1 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating radium and barium in the form of sulfates from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent and magnesium sulfate or sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating magnesium in the form of hydroxide from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating strontium in the form of hydroxide from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with a humic acid to form precipitates comprising said strontium in the form of hydroxide in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with said amine solvent to form precipitates comprising said sodium-calcium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; and (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 2 (depends on 1) The method of claim 1 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 3 (depends on 1) The method of claim 1 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 4 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating radium and barium in the form of sulfates from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent and magnesium sulfate or sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating magnesium in the form of hydroxide from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating calcium in the form of carbonate from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with sodium carbonate or a carbonate source to form precipitates comprising said calcium in the form of carbonate in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; and (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 5 (depends on 4) The method of claim 4 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 6 (depends on 4) The method of claim 4 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 7 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating radium and barium in the form of sulfates from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent and magnesium sulfate or sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating magnesium in the form of hydroxide from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating calcium in the form of chloroaluminate or chloroferrate from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with said amine solvent and a source of aluminum or iron to form precipitates comprising said calcium chloroaluminate or calcium chloroferrate in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 8 (depends on 7) The method of claim 7 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 9 (depends on 7) The method of claim 7 wherein said source of aluminum is selected from the group consisting of aluminum hydroxide, aluminum chlorohydrate, sodium aluminate, aluminum acetate, aluminum chloride, aluminum nitrate, and combinations thereof. ### Claim 10 (depends on 7) The method of claim 7 wherein said source of iron is selected from the group consisting of iron hydroxide, sodium ferrate, iron chloride, iron nitrate, and combinations thereof. ### Claim 11 (depends on 7) The method of claim 7 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 12 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating radium and barium in the form of sulfates from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent and magnesium sulfate or sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating magnesium in the form of hydroxide from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating calcium in the form of sulfoaluminate or sulfoferrate from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with sulfate-rich mine drainage water, a source of aluminum or iron, and said amine solvent to form precipitates comprising said calcium sulfoaluminate or calcium sulfoferrate in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 13 (depends on 12) The method of claim 12 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 14 (depends on 12) The method of claim 12 wherein said source of aluminum is selected from the group consisting of aluminum hydroxide, aluminum chlorohydrate, sodium aluminate, aluminum acetate, aluminum chloride, aluminum nitrate, and combinations thereof. ### Claim 15 (depends on 12) The method of claim 12 wherein said source of iron is selected from the group consisting of iron hydroxide, sodium ferrate, iron chloride, iron nitrate, and combinations thereof. ### Claim 16 (depends on 12) The method of claim 12 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 17 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating magnesium in the form of hydroxide from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating calcium in the form of chloroaluminate or chloroferrate from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent and a source of aluminum or iron to form precipitates comprising said calcium chloroaluminate or calcium chloroferrate in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating radium and barium in the form of sulfates from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with magnesium sulfate or sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with the amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 18 (depends on 17) The method of claim 17 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 19 (depends on 17) The method of claim 17 wherein said source of aluminum is selected from the group consisting of aluminum hydroxide, aluminum chlorohydrate, sodium aluminate, aluminum acetate, aluminum chloride, aluminum nitrate, and combinations thereof. ### Claim 20 (depends on 17) The method of claim 17 wherein said source of iron is selected from the group consisting of iron hydroxide, sodium ferrate, iron chloride, iron nitrate, and combinations thereof. ### Claim 21 (depends on 17) The method of claim 17 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 22 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating magnesium in the form of hydroxide from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating calcium in the form of chloroaluminate or chloroferrate from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with said amine solvent and a source of aluminum or iron to form precipitates comprising said calcium chloroaluminate or calcium chloroferrate in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating radium and barium in the form of carbonates from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with sodium carbonate or a carbonate source to form precipitates comprising said radium and barium in the form of carbonates in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 23 (depends on 22) The method of claim 22 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 24 (depends on 22) The method of claim 22 wherein said source of aluminum is selected from the group consisting of aluminum hydroxide, aluminum chlorohydrate, sodium aluminate, aluminum acetate, aluminum chloride, aluminum nitrate, and combinations thereof. ### Claim 25 (depends on 22) The method of claim 22 wherein said source of iron is selected from the group consisting of iron hydroxide, sodium ferrate, iron chloride, iron nitrate, and combinations thereof. ### Claim 26 (depends on 22) The method of claim 22 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 27 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating magnesium in the form of hydroxide from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent to form precipitates comprising said magnesium in the form of hydroxide in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce a first intermediate de-scaled produced water; (c) separating radium and barium in the form of sulfates from said first intermediate de-scaled produced water by (i) mixing said first intermediate de-scaled produced water with sulfate-rich mine drainage water to form precipitates comprising said radium and barium in the form of sulfates in a second precipitator unit; (ii) removing said precipitates from said first intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce a second intermediate de-scaled produced water; (d) separating calcium in the form of sulfoaluminate or sulfoferrate from said second intermediate de-scaled produced water by (i) mixing said second intermediate de-scaled produced water with said amine solvent and a source of aluminum or iron to form precipitates comprising said calcium sulfoaluminate or calcium sulfoferrate in a third precipitator unit; (ii) removing said precipitates from said second intermediate de-scaled produced water and recovering at least most of remaining said amine solvent from said precipitates by a third filter equipped to recover said amine solvent to produce de-scaled produced water; (e) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (f) using said de-aerated produced water for hydro-fracturing; or (g) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (h) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (i) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (j) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium chloride salt in a fourth precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a fourth filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (d) and feeding the blend stream to said stripping unit in step (e). ### Claim 28 (depends on 27) The method of claim 27 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 29 (depends on 27) The method of claim 27 wherein said source of aluminum is selected from the group consisting of aluminum hydroxide, aluminum chlorohydrate, sodium aluminate, aluminum acetate, aluminum chloride, aluminum nitrate, and combinations thereof. ### Claim 30 (depends on 27) The method of claim 27 wherein said source of iron is selected from the group consisting of iron hydroxide, sodium ferrate, iron chloride, iron nitrate, and combinations thereof. ### Claim 31 (depends on 27) The method of claim 27 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof. ### Claim 32 A method to de-oil, de-scale and de-salt produced water, said method comprising the steps of: (a) separating oil from said produced water by hydrophobic membranes to produce de-oiled produced water; (b) separating radium and barium in the form of sulfates, and magnesium and strontium in the form of hydroxides from said de-oiled produced water by (i) mixing said de-oiled produced water with an amine solvent and a humic acid to form precipitates comprising said radium and barium in the form of sulfates and said magnesium and strontium in the form of hydroxides in a first precipitator unit; (ii) removing said precipitates from said de-oiled produced water and recovering at least most of remaining said amine solvent from said precipitates by a first filter equipped to recover said amine solvent to produce de-scaled produced water; (c) recovering at least most of said amine solvent from said de-scaled produced water by a stripping unit to produce de-aerated produced water; (d) using said de-aerated produced water for hydro-fracturing; or (e) blending said de-aerated produced water with low salinity water to produce a blend stream for hydro-fracturing; or (f) de-salting said de-aerated produced water by a desalination method to produce water distillate and concentrate produced water; (g) de-salting said concentrate produced water by a thermal crystallizer to produce said water distillate and sodium-calcium chloride salt; or (h) de-salting said concentrate produced water by (i) mixing said concentrate produced water with an amine solvent to form precipitates comprising said sodium-calcium chloride salt in a second precipitator unit; (ii) removing said precipitates from said concentrate produced water and recovering at least most of remaining said amine solvent from said precipitates by a second filter equipped to recover said amine solvent to produce decanted produced water; (iii) recycling said decanted produced water by blending with said de-scaled produced water from step (b) and feeding the blend stream to said stripping unit in step (c). ### Claim 33 (depends on 32) The method of claim 32 wherein said amine solvent is selected from the group consisting of isopropylamine, propylamine, dipropylamine, diisopropylamine, ethylamine, diethylamine, methylamine, dimethylamine, and combinations thereof. ### Claim 34 (depends on 32) The method of claim 32 wherein said desalination method is selected from the group consisting of thermal vapor compression, mechanical vapor recompression, multi-effects, vacuum membrane distillation, direct contact membrane distillation, membrane osmotic distillation, multi-stage flash membrane distillation, reverse osmosis, forward osmosis, and combinations thereof.