Method and reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation

Patent metadata

Field	Value
Publication number	US-9708203-B2
Application number	US-201214395653-A
Country	US
Kind code	B2
Filing date	Jun 20, 2012
Priority date	May 29, 2012
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

The present invention provides a method and a reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation. In the method, in a single electrochemical system, an enzyme-modified electrode is combined with electro-coagulation to synergistically remove organic matters from water. Certain electrochemical parameters are controlled such that a polymerization reaction is performed between hydrogen peroxide generated by a cathode reaction and organic matters catalyzed by the immobilized-enzymatic electrode. After the polymerization reaction, the organic product enters an anode chamber through a pump. The organic product is precipitated and removed by performing a reaction between the organic product and different hydrolysis products from the electro-coagulation through a coagulating/flocculating effect of compression of a double electric layer, adsorption and electric neutralization as well as precipitation capture. Ultimately, the object of removing the organic matters synergistically through the enzymatic catalyzed polymerization at the cathode and the electro-coagulation at the anode is achieved. The present invention has a strong selectivity for low-concentration toxic organic pollutants and a good effect in removing small-molecular hydrophilic organic matters, the addition amount of enzyme is low, the cathode and the anode are fully used, the cost is reduced, the operation is simple, and the applicable is wide, therefore, the present invention is applicable to a variety of water and wastewater containing organic matters, and the contaminated water.

First claim

The invention claimed is:

1. A method for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation, comprising the steps of:
1) coupling electro-coagulation and an immobilized-enzymatic electrode in a single electrochemical system in which the cathode is an oxygenating electrode with an immobilized enzyme and the anode is an electro-coagulation sacrificial electrode;
2) separating the cathode and the anode in an electrolytic tank by a hydrogen ion exchange membrane to form a cathode chamber and an anode chamber;
3) introducing a raw water into the cathode chamber; subjecting the organic matters in the raw water to a polymerization reaction catalyzed by hydrogen peroxide generated from a cathode reaction and the immobilized-enzymatic electrode, under a certain cathode potential or a certain current density with a saturated calomel electrode as a reference electrode; and pumping the reacted raw water into the anode chamber after a certain residence time; and
4) generating fresh hydrolysis products by dissolving the metal anode in the anode chamber, under a certain anode potential or a certain current density with a saturated calomel electrode as a reference electrode; precipitating and removing the organic polymerized products, which are produced from an enzymatic catalysis reaction in the cathode chamber, by metal hydrolysis products through a coagulation/flocculation effect of compression of a double electric layer, adsorption and electric neutralization as well as precipitation capture; and discharging the treated water from the anode chamber after an electro-coagulation reaction so as to achieve the object of removing the organic matters synergistically through the enzymatic catalyzed polymerization at the cathode and the electro-coagulation at the anode.

2. The method for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 1 , wherein the immobilized enzyme on the cathode is horse radish peroxidase, lignin peroxidase, polyphenol oxidase, laccase, tyrosinase tyrosine, catechol oxidase, or hemoglobinase; and an addition amount of the enzyme is 10 U/cm 2 to 1000 U/cm 2 .

3. The method for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 1 , wherein a substrate for the cathode is graphite, active carbon, graphite felt, carbon felt, active carbon fiber, or carbon nanotube.

4. The method for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 1 , wherein the anode is an aluminum plate, an iron plate, or a ferro-aluminum plate.

5. A reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation comprising a cathode, an anode, reference electrodes, an electrolytic tank, a water pump, a hydrogen ion exchange membrane, an aeration device and a direct current power supply;
wherein the electrolytic tank is hermetically closed by rubber pads and fixation screws;
the cathode together with a reference electrode and the anode together with a reference electrode are disposed at two ends of the electrolytic tank respectively, and the hydrogen ion exchange membrane is disposed therebetween so as to form a cathode chamber and an anode chamber;
the cathode chamber is provided with the aeration device externally connected to an air compressor or an air pump so that a certain air flow enters the cathode zone to supply dissolved oxygen to a cathode solution;
the electrolytic tank and the water pump are connected with a pipeline so that a raw water is pumped into an inlet of the cathode chamber, and after an enzymatic polymerization reaction in the cathode chamber, discharged from an outlet of the cathode chamber, directed to an inlet of the anode chamber via a pipeline, and after an electro-coagulation reaction in the anode chamber, pumped out of an outlet of the anode chamber; and
the direct current power supply is connected respectively to the cathode and the anode through metal conducting wires.

6. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein the immobilized enzyme on the cathode is horse radish peroxidase, lignin peroxidase, polyphenol oxidase, laccase, tyrosinase tyrosine, catechol oxidase, or hemoglobinase; and an addition amount of the enzyme is 10 U/cm 2 to 1000 U/cm 2 .

7. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein a substrate for the cathode is graphite, active carbon, graphite felt, carbon felt, active carbon fiber, or carbon nanotube.

8. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein the anode is an aluminum plate, an iron plate, or a ferro-aluminum plate.

9. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein the distance between the cathode and the anode is ranged from 1 mm to 90 mm.

10. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein a potential at the anode is ranged from 0.2 V to 2.0 V and a potential at the cathode is ranged from −1.2 V to −0.2 V.

11. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein the residence time is ranged from 5 min to 5 h.

12. The reactor for removing organic matters by immobilized-enzymatic electrode coupled electro-coagulation according to claim 5 , wherein the air flow rate is ranged from 0.1 L/min to 100 L/min.

Assignees

• Cao Hongbin
• Zhao He
• Li Yuping
• Li Haitao
• Zhang Yi
• Inst Of Process Eng Chinese Acad

Inventors

• Cao Hongbin
• Zhao He
• Li Yuping
• Li Haitao
• Zhang Yi

Classifications

• C02F1/46109

  Electrodes · CPC title

• C02F2001/46142

  Catalytic coating · CPC title

• C02F2201/46115

  Electrolytic cell with membranes or diaphragms · CPC title

• C02F2001/46138

  Electrodes comprising a substrate and a coating · CPC title

• C02F3/005

  Combined electrochemical biological processes (aeration by electrolytically produced oxygen bubbles C02F3/202) · CPC title