Granted Patent B2

US 12,391,586 · App. 17/632,897 · Granted Aug 19, 2025

Inventors: Fazlollah Azarnoush (Helsinki, FI); Roger Barstrom (Odakra, SE)

Assignee: KEMIRA OYJ

C02F1/5245C02F1/50C02F1/72C02F2101/101C02F2101/32C02F2103/10C02F2209/06

Abstract

Claims (52)

1. A method for treating a fluid in need of treatment, wherein said method comprises adding an effective amount of at least one coagulant composition, wherein said coagulant composition comprises one or more coagulants, which one or more coagulants comprise at least one stable ferrous product, and further wherein said stable ferrous product comprises:

i. one or more ferrous (Fe 2+ ) comprising compounds;

ii. one or more citrate-based stabilizers; and

iii. a pH value of from 4.0 to 6.0;

and wherein

(a) said one or more citrate-based stabilizers maintain the stability of said coagulant composition and/or prevent the oxidation of said ferrous compound in said coagulant composition;

(b) the stable ferrous product comprises from 0.10% to less than 5.0% by weight of said citrate-based stabilizer,

(c) said one or more citrate-based stabilizers maintain the stability of said coagulant composition and prevent the oxidation of said ferrous compound in said coagulant composition; and

(d) the coagulant composition does not contain (Fe 3+ ) compounds.

2. The method of claim 1 , wherein:

(i) the one or more stable ferrous products comprise from about 0.10% to about 3.00% by weight of citrate-based stabilizer;

(ii) the one or more stable ferrous products comprise more than 5.0% of Fe by weight;

(iii) said coagulant composition comprises less than 20% by weight hydrogen peroxide;

(iv) said fluid in need of treatment comprises sulfide;

(v) said fluid in need of treatment comprises sulfide and treatment of said fluid results in 75% or less, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, 99% or more, or 100% removal of sulfide from said fluid in need of treatment;

(vi) said one or more ferrous comprising compounds include ferrous sulfate and ferrous chloride;

(vii) said one or more ferrous comprising compounds comprise ferrous chloride tetrahydrate and/or ferrous chloride from spent pickling liquor;

(viii) said one or more ferrous comprising compounds include ferrous sulfate which comprises copperas;

(ix) the citrate-based stabilizer comprises trisodium citrate;

(x) the amount of the one or more stable ferrous products in the coagulant composition is comprise about 2% or less, about 2% or more, about 2.5% or more, about 3.0% or more, about 3.5% or more, about 4.0% or more, about 4.5% or more, about 5.0% or more, about 5.5% or more, about 6.0% or more, about 6.5% or more, about 7.0% or more, about 7.5% or more, about 8.0% or more, about 8.5% or more, about 9.0% or more, about 9.5% or more, about 10.0% or more, about 11.0% or more, about 12.0% or more, about 13.0% or more, about 14.0% or more, or about 15.0% or more of Fe by weight;

(xi) the one or more stable ferrous products comprise about 0.10% or less, about 0.10% or more, about 0.20% or more, about 0.30% or more, about 0.40% or more, about 0.50% or more, about 0.75% or more, about 1.00% or more, about 1.25% or more, about 1.50% or more, about 1.75% or more, about 2.00% or more, about 2.25% or more, about 2.50% or more, about 2.75% or more, or about 3.00% or more of stabilizer by weight;

(xii) said one or more stable ferrous products comprise from about 2% to about 15% Fe by weight, about 0.1% to about 3.0% citrate by weight, and a pH value for from about 3.0 to about 6.0;

(xiii) the one or more stable ferrous products are stable at 0° C. for 1 week or more, for 2 weeks or more, for 3 weeks or more, for 4 weeks or more, for 5 weeks or more, for 6 weeks or more, for 7 weeks or more, for 8 weeks or more, for 9 weeks or more, for 10 weeks or more, for 12 weeks or more, for 14 weeks or more, for 16 weeks or more, for 18 weeks or more, for 20 weeks or more, for 22 weeks or more, or for 24 weeks or more;

(xiv) the one or more stable ferrous products are stable at 20° C. for 1 week or more, for 2 weeks or more, for 3 weeks or more, for 4 weeks or more, for 5 weeks or more, for 6 weeks or more, for 7 weeks or more, for 8 weeks or more, for 9 weeks or more, for 10 weeks or more, for 12 weeks or more, for 14 weeks or more, for 16 weeks or more, for 18 weeks or more, for 20 weeks or more, for 22 weeks or more, or for 24 weeks or more;

(xv) the one or more stable ferrous products are stable at room temperature for 1 week or more, for 2 weeks or more, for 3 weeks or more, for 4 weeks or more, for 5 weeks or more, for 6 weeks or more, for 7 weeks or more, for 8 weeks or more, for 9 weeks or more, for 10 weeks or more, for 12 weeks or more, for 14 weeks or more, for 16 weeks or more, for 18 weeks or more, for 20 weeks or more, for 22 weeks or more, or for 24 weeks or more;

(xvi) the one or more stable ferrous products are stable at 50° C. for 1 week or more, for 2 weeks or more, for 3 weeks or more, for 4 weeks or more, for 5 weeks or more, for 6 weeks or more, for 7 weeks or more, for 8 weeks or more, for 9 weeks or more, for 10 weeks or more, for 12 weeks or more, for 14 weeks or more, for 16 weeks or more, for 18 weeks or more, for 20 weeks or more, for 22 weeks or more, or for 24 weeks or more; or

(xvii) any combination of the foregoing.

3. The method of claim 1 , wherein:

(i) the one or more stable ferrous products are non-corrosive;

(ii) the one or more stable ferrous products are non-corrosive by the United Nations test method standard;

(iii) the stable ferrous product results in less than 13.5% mass loss of a metal specimen when the exposure time is 7 days to said stable ferrous product;

(iv) the stable ferrous product is non-corrosive to steel;

(v) the stable ferrous product is non-corrosive to aluminum;

(vi) the corrosion rate of said stable ferrous product is 6.25 or less or 1.0 or less mm/year at 55° C. steel and/or aluminum coupons;

(vii) the fluid in need of treatment comprises one or more digesters;

(viii) the fluid in need of treatment comprises a fluid used in, or in conjunction with, or as a part of a process of, any one or more of the following: sewer networks; pumping stations; wastewater treatment plants, deep and shallow wells, wells close to sewer lines, surface water that is close to a septic system; industrial effluent; static contaminated water; and/or wastewater comprising digesters;

(ix) the fluid in need of treatment comprises heavy metals, oil, grease, and/or sludge;

(x) the fluid in need of treatment comprises an effluent;

(xi) the fluid in need of treatment comprises produced water;

(xii) the fluid in need of treatment comprises sewage water;

(xiii) the method further comprises adding one or more other coagulants to said fluid in need of treatment;

(xiv) said method further comprises adding one or more biocides to said fluid in need of treatment;

(xv) said method further comprises adding one or more oxidizing biocides and/or one or more non-oxidizing biocides to said fluid in need of treatment;

(xvi) said method comprises adding an amount of said coagulant comprising one or more stable ferrous products to said fluid in need of treatment that is effective to remove one or more contaminants from said fluid in need of treatment; or

(xvii) any combination of the foregoing.

4. The method of claim 1 , wherein the stable ferrous product comprises from about 0.10% to about 3.00% by weight of said citrate-based stabilizer.

5. The method of claim 1 , wherein the stable ferrous product comprises more than 5.0% of Fe by weight.

6. The method of claim 1 , wherein said coagulant composition comprises less than 5% by weight of hydrogen peroxide.

7. The method of claim 1 , wherein said coagulant composition does not comprise an appreciable or biocidally effective amount of hydrogen peroxide.

8. The method of claim 1 , wherein the fluid in need of treatment comprises produced water.

9. The method of claim 1 , wherein the fluid in need of treatment comprises at least 1 mg/kg sulfide concentration.

10. The method of claim 1 , wherein the fluid in need of treatment comprises at least 5 mg/kg sulfide concentration.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (15)