US 11,851,355 B2
Methods and systems for digesting biosolids and recovering phosphorus
Richard Pressley, Cocoa Beach, FL (US); Justin Wippo, Highland, IN (US); and John H. Graham, Jr., Woodridge, IL (US)
Appl. No. 17/276,413
Filed by Richard Pressley, Cocoa Beach, FL (US); Justin Wippo, Highland, IN (US); and John H. Graham, Jr., Woodridge, IL (US)
PCT Filed Sep. 13, 2019, PCT No. PCT/US2019/051125
§ 371(c)(1), (2) Date Mar. 15, 2021,
PCT Pub. No. WO2020/056335, PCT Pub. Date Mar. 19, 2020.
Claims priority of provisional application 62/731,054, filed on Sep. 13, 2018.
Claims priority of provisional application 62/863,647, filed on Jun. 19, 2019.
Prior Publication US 2022/0073391 A1, Mar. 10, 2022
Int. Cl. C02F 11/04 (2006.01); C02F 11/12 (2019.01); C02F 11/14 (2019.01); C02F 1/66 (2023.01); C02F 3/28 (2023.01); C02F 3/30 (2023.01); C02F 3/34 (2023.01); C02F 11/02 (2006.01); C02F 101/10 (2006.01)
CPC C02F 11/04 (2013.01) [C02F 1/66 (2013.01); C02F 3/2866 (2013.01); C02F 3/308 (2013.01); C02F 3/343 (2013.01); C02F 11/02 (2013.01); C02F 11/12 (2013.01); C02F 11/14 (2013.01); C02F 3/302 (2013.01); C02F 2101/105 (2013.01); C02F 2209/005 (2013.01); C02F 2209/06 (2013.01); C02F 2209/08 (2013.01); C02F 2209/12 (2013.01); C02F 2209/14 (2013.01); C02F 2209/24 (2013.01); C02F 2301/106 (2013.01); Y02E 50/30 (2013.01); Y02W 10/20 (2015.05)] 19 Claims
OG exemplary drawing
 
1. A method for digesting biosolids and recovering phosphorus from the biosolids, the method comprising:
hydrolyzing insoluble organic polymers in a sludge derived from wastewater in an acidic hydrolysis environment to produce hydrolyzed biosolids;
fermenting the hydrolyzed biosolids in an anaerobic digestion environment to produce anaerobically digested biosolids;
optionally digesting the anaerobically digested biosolids in a thermophilic aerobic digestion environment to produce thermophilically digested biosolids;
digesting the anaerobically digested biosolids or the thermophilically digested biosolids in a mesophilic digestion environment to produce mesophilically digested biosolids;
separating the mesophilically digested biosolids into a phosphorus-rich centrate and dewatered digested phosphorus-lean biosolids; and
recovering a phosphorus-rich precipitate from the phosphorus-rich centrate.