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 |
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.
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