Flow electrode capacitive deionization system and method for recovering phosphorus in phosphogypsum leachate and synchronous performing brine desalination

Patent metadata

Field	Value
Publication number	US-12319598-B2
Application number	US-202218558732-A
Country	US
Kind code	B2
Filing date	Dec 21, 2022
Priority date	Nov 18, 2022
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A flow electrode capacitive deionization system and a method for recovering phosphorus in phosphogypsum leachate and synchronous performing brine desalination belong to the technical field of wastewater treatment and recycling. The flow electrode capacitive deionization system includes a phosphorus recovery electrodeionization module and a desalination electrodeionization module. A first flow electrode solution reservoir, a phosphorus recovery electrodeionization module cathode flow electrode chamber, and a desalination electrodeionization module anode flow electrode chamber are interconnected in a circulation. A second flow electrode solution reservoir, a phosphorus recovery electrodeionization module anode flow electrode chamber, and a desalination electrodeionization module cathode flow electrode chamber are interconnected in a circulation. Two independent flow electrode solution circulation loops are formed. The phosphogypsum leachate enters the phosphorus recovery electrodeionization module and phosphorus is enriched into a flow electrode solution. A phosphorus-rich solution is reacted with a ferrous solution under an oxygen-free condition to generate vivianite [Fe 3 (PO 4 ) 2 ·8H 2 O].

First claim

What is claimed is:

1. A flow electrode capacitive deionization system for recovering phosphorus in phosphogypsum leachate and synchronously performing brine desalination, wherein the flow electrode capacitive deionization system comprises a phosphorus recovery electrodeionization module and a desalination electrodeionization module,
the phosphorus recovery electrodeionization module comprises a phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ), a phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ), and a phosphorus recovery electrodeionization module deionization chamber ( 5 ), a first anion exchange membrane ( 4 ) is provided between the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ) and the phosphorus recovery electrodeionization module deionization chamber ( 5 ), and a first cation exchange membrane ( 6 ) is provided between the phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ) and the phosphorus recovery electrodeionization module deionization chamber ( 5 ),
the desalination electrodeionization module comprises a desalination electrodeionization module anode flow electrode chamber ( 15 ), a desalination electrodeionization module cathode flow electrode chamber ( 11 ), and a desalination electrodeionization module deionization chamber ( 13 ), a second cation exchange membrane ( 12 ) is provided between the desalination electrodeionization module cathode flow electrode chamber ( 11 ) and the desalination electrodeionization module deionization chamber ( 13 ), and a second anion exchange membrane ( 14 ) is provided between the
desalination electrodeionization module anode flow electrode chamber ( 15 ) and the desalination electrodeionization module deionization chamber ( 13 ), the flow electrode capacitive deionization system further comprises a phosphogypsum leachate reservoir ( 1 ), a brine reservoir ( 8 ), a first flow electrode solution reservoir ( 9 ), and a second flow electrode solution reservoir ( 10 ),
a liquid outlet of the phosphogypsum leachate reservoir ( 1 ) communicates with a liquid inlet of the phosphorus recovery electrodeionization module deionization chamber ( 5 ), a liquid outlet of the phosphorus recovery electrodeionization module deionization chamber ( 5 ) communicates with a liquid inlet of the phosphogypsum leachate reservoir ( 1 ), and a liquid outlet of the brine reservoir ( 8 ) communicates with a liquid inlet of the desalination electrodeionization module deionization chamber ( 13 ),
a liquid outlet of the first flow electrode solution reservoir ( 9 ) communicates with a liquid inlet of the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ), a liquid outlet of the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ) communicates with a liquid inlet of the desalination electrodeionization module cathode flow electrode chamber ( 11 ), and a liquid outlet of the desalination electrodeionization module cathode flow electrode chamber ( 11 ) communicates with a liquid inlet of the first flow electrode solution reservoir ( 9 ),
a liquid outlet of the second flow electrode solution reservoir ( 10 ) communicates with a liquid inlet of the phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ), a liquid outlet of the phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ) communicates with a liquid inlet of the desalination electrodeionization module anode flow electrode chamber ( 15 ), and a liquid
outlet of the desalination electrodeionization module anode flow electrode chamber ( 15 ) communicates with a liquid inlet of the second flow electrode solution reservoir ( 10 ), and each of the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ), the phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ), the desalination electrodeionization module anode flow electrode chamber ( 15 ), and the desalination electrodeionization module cathode flow electrode chamber ( 11 ) comprises a current collector plate ( 2 ) having a flow electrode solution flowing channel.

2. The flow electrode capacitive deionization system for recovering phosphorus in phosphogypsum leachate and synchronously performing brine desalination according to claim 1 , wherein a liquid outlet of the desalination electrodeionization module deionization chamber ( 13 ) communicates with a liquid inlet of the brine reservoir ( 8 ).

3. A method for recovering phosphorus in phosphogypsum leachate and synchronously performing brine desalination in the flow electrode capacitive deionization system according to claim 1 , wherein the method comprises following steps:
S 1 : transporting a phosphogypsum leachate and a brine respectively from the phosphogypsum leachate reservoir ( 1 ) and the brine reservoir ( 8 ) to the phosphorus recovery electrodeionization module deionization chamber ( 5 ) and the desalination electrodeionization module deionization chamber ( 13 ) in the flow electrode capacitive deionization system through a liquid pump;
transporting a first flow electrode solution through a first flow electrode circulation loop comprising the first flow electrode solution reservoir ( 9 ), the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ), the desalination electrodeionization module cathode flow electrode chamber ( 11 ), and the first flow electrode solution reservoir ( 9 );
transporting a second flow electrode solution through a second flow electrode circulation loop comprising the second flow electrode solution reservoir ( 10 ), the phosphorus recovery electrodeionization module cathode flow electrode chamber ( 7 ), the desalination electrodeionization module anode flow electrode chamber ( 15 ), and the second flow electrode solution reservoir ( 10 ), wherein
a liquid inflow mode of the phosphogypsum leachate is batch-mode, wherein the batch-mode is that the phosphogypsum leachate is transported from the phosphogypsum leachate reservoir ( 1 ) to the phosphorus recovery electrodeionization module deionization chamber ( 5 ) through the liquid pump and returns to the phosphogypsum leachate reservoir ( 1 ) after deionization treatment, and wherein the phosphogypsum leachate enters the phosphorus recovery electrodeionization module ( 5 ), phosphate migrates to the phosphorus recovery electrodeionization module anode flow electrode chamber ( 3 ), follows the flow electrode to the desalination electrodeionization module cathode flow electrode chamber ( 11 ), and is desorbed and enriched into the flow electrode solution by a reverse voltage,
a liquid inflow mode of the brine is single-pass, wherein the single-pass is that the brine is transported from the brine reservoir ( 8 ) to the desalination electrodeionization module deionization chamber ( 13 ) through the liquid pump and is transported out of the flow electrode capacitive deionization system after deionization treatment;
S 2 : operating the phosphorus recovery electrodeionization module and the desalination electrodeionization module at a same current and controlling an inflow velocity of the phosphogypsum leachate, an inflow velocity of the brine, and a circulation velocity of the flow electrode solution; and
S 3 : obtaining a purified phosphorus-rich solution from the first flow electrode solution reservoir ( 9 ).

4. The method according to claim 3 , wherein in step S 1 , the phosphogypsum leachate is a purified solution after filtration or sedimentation, wherein a total suspended solids does not exceed 0.5 mg/L, a total content of calcium element and magnesium element does not exceed 2000 mg/L, a content of aluminum element does not exceed 600 mg/L, a content of fluorine element

Assignees

• Univ Huazhong Science Tech

Inventors

• Liang Sha
• Yang Fan
• Yang Jiakuan
• Guo Xiao
• Chen Shuai
• Yuan Shushan
• Yu Wenbo
• Hu Jingping
• Hou Huijie
• Huang Liang
• Duan Huabo

Classifications

• B01D61/4281

  comprising multiple membrane capacitive deionization steps · CPC title

• C25B9/43

  comprising fluidised bed electrodes · CPC title

• C02F2201/4618

  Supplying or removing reactants or electrolyte · CPC title

• C02F2201/46

  Apparatus for electrochemical processes · CPC title

• C02F2101/105

  Phosphorus compounds · CPC title