US 12,391,586 B2
Compositions and methods for treating wastewater
Fazlollah Azarnoush, Helsinki (FI); and Roger Barstrom, Odakra (SE)
Assigned to KEMIRA OYJ, Helsinki (FI)
Appl. No. 17/632,897
Filed by KEMIRA OYJ, Helsinki (FI)
PCT Filed Aug. 6, 2020, PCT No. PCT/US2020/045193
§ 371(c)(1), (2) Date Feb. 4, 2022,
PCT Pub. No. WO2021/026346, PCT Pub. Date Feb. 11, 2021.
Claims priority of provisional application 62/883,200, filed on Aug. 6, 2019.
Claims priority of application No. 20195746 (FI), filed on Sep. 10, 2019.
Prior Publication US 2024/0140839 A1, May 2, 2024
Int. Cl. C02F 1/52 (2023.01); C02F 1/50 (2023.01); C02F 1/72 (2023.01); C02F 101/10 (2006.01); C02F 101/32 (2006.01); C02F 103/10 (2006.01)
CPC C02F 1/5245 (2013.01) [C02F 1/50 (2013.01); C02F 1/72 (2013.01); C02F 2101/101 (2013.01); C02F 2101/32 (2013.01); C02F 2103/10 (2013.01); C02F 2209/06 (2013.01)] 10 Claims
OG exemplary drawing
 
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 (Fe2+) 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 (Fe3+) compounds.