Process and facility for recovering phosphorus at a wastewater treatment plant with advanced sludge treatment

Patent metadata

Field	Value
Publication number	US-10773983-B2
Application number	US-201716327190-A
Country	US
Kind code	B2
Filing date	Aug 22, 2017
Priority date	Aug 22, 2016
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

Disclosed is a process and a facility for recovering phosphorus present in an effluent to be treated, including the following steps: a step of biological removal of phosphorus from the effluent to be treated, a step of separating the treated water from step i and the sludge, a step of anaerobic hydrolysis of at least one portion of the sludge from step ii, a step of liquid/solid separation of the effluents from step iii, a step of advanced treatment of at least one portion of the sludge from step iv, a step of recirculation to step iii of at least one portion of the effluent from step v, and a step of recovering the phosphorus present in the effluent from step iv.

First claim

The invention claimed is:

1. A process for recovering the phosphorus present in an effluent to be treated, comprising the following steps:
i. a step of biological dephosphatation of the effluent to be treated, said step comprising:
i.1. at least one step of treatment under anaerobic conditions, and
i.2. at least one step of treatment under aerobic conditions;

ii. a step of separating said treated effluent from step i, in particular the treated water from step i and the sludge;
iii. a step of anaerobic hydrolysis of at least one portion of the sludge from step ii;
iv. a step of liquid/solid separation of the effluent from step iii;
v. a step of advanced treatment of at least one portion of the sludge from step iv;
vi. a step of recirculating, to step iii, at least one portion of the liquid effluent from step v; and
vii. a step of recovering the phosphorus present in the liquid effluent from step iv.

2. The process as claimed in claim 1 , further comprising an anaerobic digestion step between steps iv and v.

3. The process as claimed in claim 2 , further comprising a biogas exploitation step after the anaerobic digestion step.

4. The process as claimed in claim 3 , wherein the liquid from step vii is recirculated to step i.

5. The process as claimed in claim 3 , wherein the residence time of the effluent from step ii is less than 4 h.

6. The process as claimed in claim 2 , wherein the liquid from step vii is recirculated to step i.

7. The process as claimed in claim 2 , wherein the residence time of the effluent from step ii is less than 4 h.

8. The process as claimed in claim 1 , wherein the liquid from step vii is recirculated to step i.

9. The process as claimed in claim 8 , wherein the residence time of the effluent from step ii is less than 4 h.

10. The process as claimed in claim 1 , wherein the residence time of the effluent from step ii is less than 4 h.

11. The process of claim 10 , wherein the residence time of the effluent from step ii is between 30 min and 4 h.

12. The process of claim 10 , wherein the residence time of the effluent from step ii is between 30 min and 2 h.

13. The process as claimed in claim 1 wherein the degree of phosphorus recovery is greater than approximately 30% of the total phosphorus entering.

14. The process of claim 13 , wherein the degree of phosphorus recovery is greater than approximately 40% of the total phosphorus entering.

15. The process of claim 13 , wherein the degree of phosphorus recovery is between 40% and 80% of the total phosphorus entering.

16. The process of claim 13 , wherein the degree of phosphorus recovery is between 45% and 60% of the total phosphorus entering.

17. A facility for recovering the phosphorus present in an effluent to be treated, comprising at least one anaerobic reactor ( 1 ), at least one aerobic reactor ( 2 ), a separator ( 5 ), at least one phosphorus release reactor ( 10 ), at least one advanced sludge treatment unit ( 9 ), at least one means for communication between the at least one phosphorus release reactor and the at least one advanced treatment unit, and at least one phosphorus recovery unit ( 8 ).

18. The facility as claimed in claim 17 , further comprising at least one means for communication between the at least one phosphorus recovery unit and the at least one anaerobic reactor and/or the at least one aerobic reactor.

19. The facility as claimed in claim 17 , further comprising an anaerobic digester.

20. The facility as claimed in claim 17 , wherein the facility is coupled with a facility for biogas exploitation.

Assignees

• Suez Int

Inventors

• Delahaye Mathieu

Classifications

• C02F11/04

  Anaerobic treatment; Production of methane by such processes · CPC title

• C02F2303/06

  Sludge reduction, e.g. by lysis · CPC title

• Y02E50/30

  Fuel from waste, e.g. synthetic alcohol or diesel · CPC title

• C02F3/308 Primary

  Biological phosphorus removal · CPC title

• C02F2101/105

  Phosphorus compounds · CPC title