Electrified Membrane Flow-Cell Reactor For Concurrent Nitrate Reduction And Ammonia Production From Wastewater

Patent metadata

Field	Value
Publication number	US-2023365442-A1
Application number	US-202318143220-A
Country	US
Kind code	A1
Filing date	May 4, 2023
Priority date	May 10, 2022
Publication date	Nov 16, 2023
Grant date	—

Abstract

Disclosed is an electrified membrane flow-cell reactor system and method for nitrogen wastewater treatment and upcycling towards ammonia nitrogen without external acid/base consumption. This electrified membrane flow-cell reactor includes a cathodic membrane module having a gas-permeable or gas-exchange membrane and a cathodic catalytic layer, an anode, and a semi-permeable membrane between the cathodic and anodic chamber. Three chambers in the flow-cell reactor include (i) a cathode chamber for nitrate reduction and upcycling towards NH 3 , (ii) a trap chamber for NH 3 capture and storage, and (iii) an anode chamber for H + production and protonation of gaseous NH 3 to NH 4 + . The cathodic membrane and anode are connected to an electric power source to provide a stable cathodic potential and enable electrode reactions. This method will continuously treat nitrate-containing wastewater and achieve simultaneous electrochemical nitrate reduction from the wastewater and ammonia recovery as ammonium salts in the trap chamber.

First claim

1 . A method of wastewater treatment, comprises:
using an electrified membrane flow-cell reactor including a cathode chamber, an anode chamber, and a trap chamber for nitrate upcycling towards ammonia; conducting a nitrogen containing wastewater treatment and upcycling towards ammonia (NH 3 ) in the cathode chamber with a special three-phase interface membrane module design and fabrication; wherein a catalytic layer and a hydrophobic gas-permeable membrane are located in the cathodic membrane module; conducting an ammonia (NH 3 ) transport across the hydrophobic gas-permeable membrane and a subsequent capture of the ammonia in the trap chamber; and conducting a hydrogen ion (H + ) production and protonation of gaseous ammonia (NH 3 ) to ammonium (NH 4 + ) in the trap chamber or the anode chamber; wherein wastewater is treated by removing nitrogen and upcycling towards ammonia nitrogen fertilizer without using an external acid or having base consumption.

2 . The method of claim 1 , further includes utilizing the anodic chamber to produce acids to absorb ammonia into ammonium salts without the use of an external acid.

3 . The method of claim 1 , further includes redirecting the fluid containing NH 3 and hydrogen gas (H 2 ) from the cathode chamber into the anodic chamber to shift water oxidation to hydrogen gas (H 2 ) oxidation and harvest the chemical energy from the hydrogen gases to decrease the total cell voltage and energy consumption of the electrified membrane flow-cell system.

4 . The method of claim 3 , further includes connecting the cathodic membrane module and the anode membrane module to at least one of a power source to enable a cathodic potential and an electrode reaction, a potentiostat, an electrochemical working station, or any combination thereof.

5 . The method of claim 1 , wherein the catalytic layer in the cathodic membrane module has materials selected from a group of metals, metal alloys, composite materials, nanocomposite materials, nanoparticles, and combinations thereof.

6 . The method of claim 1 , wherein the catalyst layer is formed by surface coating, doping or mechanical attachment of catalysts onto the gas exchange hydrophobic membranes.

7 . The method of claim 6 , wherein the surface coating and doping methods include physical coating techniques and chemical coating techniques.

8 . The method of claim 7 , wherein the physical coating techniques include at least one selected from the group physical vapor deposition, dip coating, spin coating, casting, filtration-evaporation, lay-by-layer assembly, and any combination thereof.

9 . The method of claim 7 , wherein the chemical coating techniques include at least one selected from the group coupling agents, sol-gel method, chemical vapor deposition, surface grafting, in situ growth, and any combination thereof.

10 . The method of claim 1 , further includes providing a mechanical attachment to the electrified membrane flow-cell reactor module by clipping different forms of a catalyst-containing platform onto the gas-permeable hydrophobic membrane.

11 . The method of claim 10 , wherein the catalyst-containing platform is selected from the group a sheet, a mesh, a foam, a hollow fiber, a porous membrane, a lamellar membrane, and any combination thereof.

12 . A system for wastewater treatment, comprising an electrified membrane flow-cell reactor, the electrified membrane flow-cell reactor comprises:
a cathode chamber, an anode chamber, and a trap chamber for optimal nitrate upcycling towards ammonia as compared to not using the electrified membrane flow-cell reactor.

13 . The system of claim 12 , wherein the cathode chamber further includes a gas exchange membrane and materials of the gas exchange membrane in the cathodic chamber is selected from a group of polytetrafluoroethylene (PTFE), polypropylene (PP), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), and any combinations thereof.

14 . The system of claim 13 , wherein materials of the gas exchange membrane in cathodic membrane has a structural configuration selected from the group of flat, tubular, hollow fibers, porous, and any combination thereof.

15 . The system of claim 12 , further comprises a semi-permeable or a selective membrane integrated to separate the cathode chamber and the anode chamber.

16 . The system of claim 15 , wherein the semi-permeable or the selective membrane is selected from the group of a proton exchange membrane (PEM), a cation exchange membrane, an anion exchange membrane, and any combinations thereof.

17 . The system of claim 12 , wherein the anode chamber has an anode and the anode is selected from the group of metals, metal alloys, composite materials, nanocomposite materials, nanoparticles, and any combinations thereof.

18 . A system for wastewater treatment, comprising an electrified membrane flow-cell reactor, the electrified membrane flow-cell reactor comprises:
a cathodic membrane chamber having a gas-permeable or a gas-exchange membrane and a cathodic catalytic layer, wherein the cathode chamber is for nitrate reduction and upcycling towards NH 3 ; an anode chamber for H + production and protonation of gaseous NH 3 to NH 4 + ; a semi-permeable membrane or a gas-permeable hydrophobic membrane disposed between the cathodic membrane chamber and anode chamber; and a trap chamber for NH 3 capture and storage.

19 . The system of claim 18 further comprises a mechanical attachment for holding the cathodic membrane chamber, the anode chamber, and the trap chamber together, the mechanical attachment is a catalyst-containing platform clipped onto the gas-permeable hydrophobic membrane, and wherein the catalyst-containing platform is selected from the group of a sheet, a mesh, a foam, hollow fibers, a porous membrane, a lamellar membrane, and any combination thereof.

20 . The system of claim 18 further comprises an electric power source connected to the cathodic membrane chamber and anode chamber to provide a stable cathodic potential and an electrode reaction.

Assignees

• New Jersey Inst Technology
• Univ Qingdao Technology

Inventors

• Zhang Wen
• Gao Jianan
• Jiang Bo

Classifications

• C02F1/4676 Primary

  by electroreduction · CPC title

• C02F1/46104

  Devices therefor; Their operating or servicing · CPC title

• C02F1/4672

  by electrooxydation · CPC title

• C05C3/00 Primary

  Fertilisers containing other salts of ammonia or ammonia itself, e.g. gas liquor · CPC title

• C02F2101/163

  Nitrates · CPC title