US 12,168,618 B2
Phospate recovery by acid retardation
Thomas Kenneth Mallmann, Rockford, IL (US); Justin W. Higgs, Nolensville, TN (US); and Kenneth Ray Workman, Autryville, NC (US)
Assigned to Evoqua Water Technologies LLC, Pittsburgh, PA (US)
Filed by Evoqua Water Technologies LLC, Pittsburgh, PA (US)
Filed on Aug. 18, 2020, as Appl. No. 16/996,277.
Application 16/996,277 is a continuation of application No. 15/124,564, granted, now 10,843,941, previously published as PCT/US2015/019149, filed on Mar. 6, 2015.
Claims priority of provisional application 61/950,359, filed on Mar. 10, 2014.
Prior Publication US 2020/0377386 A1, Dec. 3, 2020
Int. Cl. C02F 1/42 (2023.01); C01B 25/18 (2006.01); C01B 25/234 (2006.01); C02F 1/00 (2023.01); C02F 1/04 (2023.01); C02F 1/44 (2023.01); C02F 1/66 (2023.01); B01J 39/04 (2017.01); B01J 41/04 (2017.01); C02F 101/10 (2006.01)
CPC C02F 1/42 (2013.01) [C01B 25/18 (2013.01); C01B 25/234 (2013.01); C02F 1/008 (2013.01); C02F 1/04 (2013.01); C02F 1/441 (2013.01); C02F 1/66 (2013.01); B01J 39/04 (2013.01); B01J 41/04 (2013.01); C02F 2001/422 (2013.01); C02F 2001/425 (2013.01); C02F 2101/105 (2013.01); C02F 2209/005 (2013.01); C02F 2209/006 (2013.01); C02F 2209/06 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A system comprising:
a vessel comprising a sorption agent;
a source of a process water stream comprising a first concentration of phosphoric acid and at least one salt, the source of the process water stream fluidly connected to an inlet of the vessel;
a source of water having an outlet fluidly connected to the vessel;
an effluent outlet of the vessel;
a valve fluidly coupled to the effluent outlet of the vessel;
a high salts effluent storage unit fluidly coupled to the valve;
a recovered phosphoric acid storage unit fluidly coupled to the valve;
a source of a pH adjuster fluidly connected to the process water stream;
a pH sensor configured to detect a pH of the process water stream and to output a pH signal indicative of the pH; and
a controller operably coupled to the pH sensor and to the source of pH adjuster, the controller configured to receive the pH signal and to send a control signal to the source of pH adjuster causing the source of pH adjuster to dispense pH adjuster into the process water stream to be treated in response to receiving the signal, the controller configured to dispense pH adjuster to adjust the pH of the process water stream to be between about 1 and about 1.5 in a first mode or between about 2 and about 3 in a second mode,
wherein the controller is further operably coupled to the valve and configured to control the valve to output a first effluent stream having a second concentration of phosphoric acid through the effluent outlet to the high salts effluent storage unit for a first period of time and to output a second effluent having a third concentration of phosphoric acid through the effluent conduit to the recovered phosphoric acid storage unit for a second period of time, the third concentration being higher than the second concentration.