Method for treating a black and odorous water body with a bionic process

Abstract

The present application provides a method for treating a black and odorous water body comprising the following steps: pre-treating the black and odorous water body; passing the pre-treated water body through a biomimetic intestine tubular purification system which imitates a digestion of small intestine; passing the tubular purification system-treated water body into a microbial fuel cell which imitates a digestion of large intestine to treat the water body; and pumping the microbial fuel cell-treated water body into an upward flow inclined tube sedimentation tank to treat the water body.

Claims

1. A method for treating a black and odorous water body comprising: (a) pre-treating the black and odorous water body, wherein the pre-treating comprises physically filtering the black and odorous water body through barriers with different thicknesses, subsequently adjusting the pH of the water body between 6.8 and 8.0, and then adding a biological enzyme to treat the water body; (b) passing the pre-treated water body through a tubular purification system which has an intestinal-like structure, wherein the tubular purification system comprises one or more tubular structures, each comprising an outer wall and a folded inner wall which imitates the inner wall of small intestine; villus-like structures which imitate small intestine villi are densely disposed on the folded inner wall; the villus-like structures are capable of providing support for intestinal probiotics; and an aeration unit is disposed at the bottom of the tubular structures, and is able to provide oxygen into the tubular structures; (c) passing the water body through the tubular purification system which has an intestinal-like structure into a microbial fuel cell, wherein the microbial fuel cell has two chambers, one comprising a microbial anode and the other comprising an air cathode; a glass fiber membrane is provided between the anode chamber and the cathode chamber as a proton exchange membrane; an external circuit connects the anode with the cathode through a conducting wire; a mixed microflora is attached to the surface of the anode and further degrades the organic materials in the water body treated by the tubular purification system under an anaerobic environment in the anode chamber; and the aeration unit disposed at the bottom of the tubular structure of the tubular purification system is capable of providing oxygen for the cathode chamber; (d) pumping the water body treated by the microbial fuel cell into an inclined tube sedimentation tank, wherein the inclined tube sedimentation tank comprises a water inlet, a honeycomb-like inclined tube sedimentation area, a water collecting tube, a water outlet, a sludge collecting bucket, a perforated sludge discharge tube, and a sludge tank; the water inlet is positioned below the honeycomb-like inclined tube sedimentation area and the water outlet is positioned above the honeycomb-like inclined tube sedimentation area; the honeycomb-like inclined tube sedimentation area comprises a plurality of inclined tube structures; the inclined tube structures accumulate the suspended or solidified materials from the incoming water into a thin sludge layer on the bottom surface of the inclined tube structures; the thin sludge layer slides back to a sludge suspension layer under gravity, and then sinks into the sludge collecting bucket, and is discharged into the sludge tank via the perforated sludge discharge tube; and a supernatant rises to the water collecting tube and is discharged via the water outlet; wherein the energy required for performing the method is from the energy generated by one or more solar cell panels and the microbial fuel cell.

2. The method according to claim 1, wherein the biological enzyme used in step (a) is a redox enzyme.

3. The method according to claim 1, wherein when the redox potential in the tubular structures is less than 0 or the dissolved oxygen in the tubular structures is less than 1 mg/L, the aeration unit starts to aerate, and when the redox potential in the tubular structures is more than 200 mv or the dissolved oxygen in the tubular structures is more than 3 mg/L, the aeration of the aeration unit stops.

4. The method according to claim 1, wherein the outer wall of the tubular structures in the tubular purification system is made from a material selected from the group consisting of a polymeric material, and a conducting metal material.

5. The method according to claim 1, wherein the folded inner wall of the tubular structures in the tubular purification system is made from polypropylene or polyethylene, and the villus-like structures are made from positively charged carbon fiber.

6. The method according to claim 1, wherein the one or more tubular structures further comprise intestinal probiotics on the villus-like structures and the intestinal probiotics comprises anaerobic bacteria, facultative bacteria, and aerobic bacteria.

7. The method according to claim 6, wherein in step (b), at the starting of the tubular purification system, the intestinal probiotics comprise Phascolafctobacterium and Eubacterium eligens; on 12 to 15 days after the starting of the system, the intestinal probiotics comprise Bacteroides and Lachnospiraceae Roseburia; and on 180 days after the starting of the system, the intestinal probiotics comprise an intestinal butyric acid-producing bacteria.

8. The method according to claim 1, wherein the mixed microflora in step (c) comprises Bacteroides and Lachnospiraceae Roseburia.

9. The method according to claim 1, wherein in step (c), when the current density of the microbial fuel cell is less than 10 mA.Math.cm.sup.2, an additional mixed microflora is supplemented.

10. The method according to claim 1, wherein in step (c), the mixed microflora degrades organic materials under an anaerobic environment in the anode chamber to release electrons and protons; the electrons are transported between biological components and the anode via electron transport media, and are transported to the cathode via the external circuit to generate current, while the protons are transported to the cathode via the proton exchange membrane; and the oxygen introduced by aeration is reduced by receiving electrons at the cathode and binds to the protons to produce water.

11. The method according to claim 2, wherein the redox enzyme is glucose oxidase, glucose dehydrogenase, or ethanol dehydrogenase.

12. The method according to claim 4, wherein the polymeric material is glass fiber reinforced plastic, polyethylene, or polypropylene.

13. The method according to claim 4, wherein the conducting metal material is stainless steel.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of the device for treating a black and odorous water body with a bionic process according to the present disclosure. The device consists of the following 4 parts: A. a pre-treatment unit, B. a biomimetic intestine tubular purification system, C. a microbial fuel cell, and D. an inclined tube sedimentation tank.

DESCRIPTION OF REFERENCE NUMBERS FOR MAIN COMPONENTS IN THE DRAWINGS

(2) A. pre-treatment unit

(3) 1water pump; 2thin barrier; 3thick barrier; 4water inlet; 5biological enzyme; 6water outlet;

(4) B. biomimetic intestine tubular purification system

(5) 7water pump; 8tubular outer wall; 9tube inner cavity; 10folded small intestine inner wall; 11tiny villi; 12aerator; 13water inlet; 14water collecting multihole tube; 15solar cell panel; 16water outlet;

(6) C. microbial fuel cell

(7) 17water pump; 18water inlet; 19water outlet; 20anode, to the surface of which a mixed microflora or a special flora is adhered; 21anode chamber; 22proton exchange membrane; 23cathode; 24cathode chamber; 25oxygen inlet; 26electric appliance;

(8) D. inclined tube sedimentation tank

(9) 27

(10) water pump; 28water inlet; 29perforated sludge discharge tube; 30sludge bucket; 31inclined tube; 32water collecting multihole tube; 33water outlet; 34sludge tank;

(11) E. enlarged view of the biomimetic intestine tubular purification system

(12) F. sectional view of the inclined tube sedimentation tank

DETAILED DESCRIPTION

(13) The device of the present disclosure is placed in a black and odorous river channel. A river water is first pumped into the pre-treatment unit A from the bottom water inlet 4 by the water pump 1, physically filtered via the thick barrier 3 and the thin barrier 2 in the pre-treatment unit, adjusted to a certain pH, degraded by the biological enzyme 5, and pumped into the tube inner cavity 9 via the water inlet 13 from the water inlet 6 by the water pump 7. The river water moves upward along the inner cavity, and the organic materials are contacted with the folded small intestine inner wall 10, oxidized, degraded, and metabolized. At the same time, the bubbles produced by the aerator 12 are cut by the tiny villi 11 into small bubbles, which provide high concentration active oxidant for the small intestine tubular purification system B, enhancing the oxidation and degradation reaction. The treated river water is pumped into the microbial fuel cell C via the water outlet 16 and the water inlet 18 from the water collecting multihole tube 14 by the water pump 17. A metabolized intermediate product is degraded with a mixed microflora or a special flora adhered to the anode 20 in the anode chamber 21. The protons are transported to the cathode chamber 24 through the proton exchange membrane 22. The oxygen is introduced into the cell via the oxygen inlet 25 from the outside, and accepts the protons at the cathode 23. The cell is externally connected with the electrical appliance 26. A efficient power generation of the microbial fuel cell and an advanced treatment of river water are achieved.

(14) The aerator 12 is dually controlled in terms of the redox potential and dissolved oxygen. When the redox potential is more than 200 mv or the dissolved oxygen is more than 3 mg/L, the aeration is stopped. And when the redox potential is less than 0 mv or the dissolved oxygen is less than 1 mg/L, the aeration starts.

(15) At a beginning of starting of the biomimetic intestine tubular purification system B, microorganisms are added in an amount of 100 g/m.sup.3 river water, and the microorganisms are anaerobic bacteria and facultative bacteria, predominantly Phascolafctobacterium and Eubacterium eligens. On 12 to 15 days after the starting of the system, Bacteroides and Lachnospiraceae Roseburia are added in an amount of 120-150 g/m.sup.3 river water; and on 180 days after the starting of the system, an intestinal butyric acid-producing bacteria is added in an amount of 200-300 g/L.

(16) In the microbial fuel cell C, Bacteroides and Lachnospiraceae Roseburia are mainly added in an amount of 500 g/m.sup.3 river water. When the current density of the microbial fuel cell is less than 10 mA.Math.cm.sup.2, Bacteroides and Lachnospiraceae Roseburia are added in an amount of 200 g/m.sup.3 river water per addition.

(17) The treated river water is pumped into the inclined tube sedimentation tank D via the water inlet 28 from the water outlet 19 by the water pump 27. The bottom sludge is sedimented at the inclined tube 31, and then discharged into the sludge tank 34 via the sludge collecting bucket 30 and the perforated sludge discharge tube 29. Clean water is collected by the water collecting multihole tube 32 above, and discharged into the river channel via the water outlet 33.

(18) The energy generated by the microbial fuel cell C and the solar cell panel 15 is supplied to aeration and water body introduction systems, thereby achieving the energy self-supply of the device.

(19) The quality of the outgoing water treated by the device complies with grade IV water quality requirement of Environmental quality standards for surface water (GB 3838-2002). According to one embodiment of the present disclosure, after treating the incoming water from a black and odorous water body with a chemical oxygen demand (COD) of 85 mg/L, an ammonia nitrogen amount of 3.0 mg/L, and a total phosphorus amount of 0.6 mg/L according to the present disclosure, the chemical oxygen demand (COD) is reduced to 20 mg/L, the ammonia nitrogen amount is reduced to 1.1 mg/L, and the total phosphorus amount is reduced to 0.18 mg/L. The energy recovery rate is up to 40%.