US 11,787,719 B2
Struvite recovery and phosphorus management techniques for wastewater treatment plants
Charles M. Wanstrom, Maplewood, MN (US); Thomas M. Anderson, Naples, FL (US); and Wim H. M. Moerman, Deerlijk (BE)
Assigned to Schwing Bioset, Inc., Somerset, WI (US)
Filed by Schwing Bioset, Inc., Somerset, WI (US)
Filed on Sep. 12, 2022, as Appl. No. 17/942,764.
Application 17/942,764 is a continuation of application No. 16/157,366, filed on Oct. 11, 2018, granted, now 11,440,825.
Claims priority of provisional application 62/570,800, filed on Oct. 11, 2017.
Prior Publication US 2023/0002265 A1, Jan. 5, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C02F 9/00 (2023.01); C02F 3/28 (2023.01); C02F 101/10 (2006.01); C02F 11/04 (2006.01); C02F 11/12 (2019.01); C02F 1/66 (2023.01)
CPC C02F 9/00 (2013.01) [C02F 1/66 (2013.01); C02F 3/286 (2013.01); C02F 11/04 (2013.01); C02F 11/12 (2013.01); C02F 2101/105 (2013.01); C02F 2301/106 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A waste treatment process comprising:
supplying waste activated sludge to a thermophilic digester;
processing the waste activated sludge in a thermophilic digester to produce a thermophilic digestate;
increasing pH of the thermophilic digestate downstream of the thermophilic digester;
concurrently with increasing pH of the thermophilic digestate and prior to any other processing, cooling the thermophilic digestate in a heat exchanger/air stripper;
wherein increasing pH of the thermophilic digestate downstream of the thermophilic digester inhibits struvite scaling during cooling the thermophilic digestate in the heat exchanger; and
separating struvite from the treated digestate.