Sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell sewage treatment system

Abstract

The utility model discloses a sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell sewage treatment system which comprises a container main body, the container main body sequentially comprises a gravel water distribution layer, a granular activated carbon anode layer, a sulfur autotrophic denitrification filter material layer, a middle gravel layer, a granular activated carbon cathode layer and a wetland plant layer from bottom to top, anodes are embedded in the granular activated carbon anode layer, cathodes are embedded in the granular activated carbon cathode layer, and the wetland plant layer is arranged in the middle gravel layer. A lead penetrates through the granular activated carbon anode layer and the granular activated carbon cathode layer to connect the anode with the cathode, a water inlet is formed in the gravel water distribution layer, and a water outlet is formed in the wetland plant layer. According to the utility model, the constructed wetland microbial fuel cell and the sulfur autotrophic denitrification technology are combined, so that the dual effects of pollutant removal and electricity generation are realized, a new idea is provided for the combination of the constructed wetland microbial fuel cell and the sulfur autotrophic denitrification technology, and meanwhile, a new direction is provided for the removal of river sewage.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewage treatment technical field, concretely relates to a kind of sulphur autotrophic denitrification filter material reinforced artificial wetland microbial fuel cell sewage treatment system. BACKGROUND

[0002] Constructed wetland (CWs) treatment technology is a kind of comprehensive ecological system for treating sewage, which is a controllable ecological sewage treatment technology artificially constructed and controlled based on the simulation of natural wetlands. CWs mainly treat sewage through plant absorption, adsorption, sedimentation, microbial degradation, etc., to achieve efficient purification and treatment of sewage, and are widely used in ecological governance and restoration. Microbial fuel cells convert organic matter in pollutants into electrical energy through microorganisms, using microorganisms as biological catalysts to generate electrons through anaerobic oxidation of energy-rich organic matter. As a new sewage treatment technology, microbial fuel cells have the advantages of pollutant treatment and power generation, and have good development prospects.

[0003] The traditional constructed wetland has low removal efficiency of pollutants, mainly because of the lack of availability of suitable electron acceptors in most constructed wetlands, which hinders the effective oxidation of pollutants and leads to the non-diffusion of air to the deep part of the constructed wetland. Sulfur autotrophic denitrification is a process in which sulfur is used as an electron donor for denitrification and nitrate is used as an electron acceptor in an anaerobic environment, and nitrate is converted to nitrogen gas under the action of sulfur autotrophic denitrifying bacteria. Compared with traditional biological denitrification process, sulfur autotrophic denitrification technology does not require additional carbon source, has less sludge production and low cost, and has been widely concerned at home and abroad, and has good application in many aspects. However, there are few studies on the combination of sulfur autotrophic denitrification and constructed wetland-microbial fuel cell for treating sewage. Based on this, the utility model patent is proposed. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the utility model provides a sulphur autotrophic denitrification filter material reinforced artificial wetland microbial fuel cell sewage treatment system to solve the problems raised in the above background art.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] The application discloses a kind of sulfur autotrophic denitrification filter material enhanced artificial wetland microbial fuel cell sewage treatment systems, including container main body, the container main body sequentially includes gravel water distribution layer from bottom to top, granular activated carbon anode layer, sulfur autotrophic denitrification filter material layer, intermediate gravel layer, granular activated carbon cathode layer and wetland plant layer, anode is buried in the granular activated carbon anode layer, cathode is buried in the granular activated carbon cathode layer, wire is passed through the granular activated carbon anode layer and granular activated carbon cathode layer to make anode and cathode connection, water inlet is provided in the gravel water distribution layer, and water outlet is provided in the wetland plant layer.

[0007] Further, resistance is provided in the wire connecting the anode and the cathode.

[0008] Further, one end of the water inlet is connected with a peristaltic pump and a wastewater bucket through a water pipe.

[0009] Further, the anode and the cathode are made of activated carbon particles wrapped with stainless steel mesh, and the stainless steel mesh is 12 mesh.

[0010] Further, the particle size of the gravel water distribution layer is 30-50 mm, the particle size of the intermediate gravel layer is 10-20 mm, the particle size of the granular activated carbon anode layer is 3-5 mm, the particle size of the sulfur autotrophic denitrification filter material layer is 3-5 mm, and the particle size of the granular activated carbon cathode layer is 3-5 mm.

[0011] Further, the thickness of the gravel water distribution layer is 15-25 cm, the thickness of the granular activated carbon anode layer is 5-8 cm, the thickness of the sulfur autotrophic denitrification filter material layer is 5-8 cm, the thickness of the intermediate gravel layer is 15-25 cm, and the thickness of the granular activated carbon cathode layer is 5-8 cm.

[0012] Further, the container main body is a cylinder with a diameter not less than 200 mm.

[0013] Further, the thickness ratio of the gravel water distribution layer, the granular activated carbon anode layer, the sulfur autotrophic denitrification filter material layer, the intermediate gravel layer, and the granular activated carbon cathode layer is 3:1:1:3:1.

[0014] The container main body divides the artificial wetland into an anaerobic bottom and an aerobic top, forming a gradually increasing oxidation-reduction gradient from the bottom to the top, which provides conditions for the combination of the microbial fuel cell and the artificial wetland.

[0015] By setting the cathode at the top of the device in the aerobic place, the anode at the bottom in the anaerobic place, connecting through the external lead, the anode oxidizes and degrades the organic matter into inorganic matter, electron and hydrogen ion through the microbial action; the electron is transmitted to the cathode through the lead, and the cathode generates water through the reaction of oxygen, electron and hydrogen ion in the aerobic area. In this process, the device realizes the effective removal of pollutants and generates electric energy, which is a new green sewage treatment technology combining the constructed wetland and the microbial fuel cell, called constructed wetland microbial fuel cell.

[0016] In the sulfur autotrophic denitrification-constructed wetland-microbial fuel cell, the electrons generated by the microbial fuel cell can accelerate the treatment of sewage by sulfur autotrophic denitrification. The device combines sulfur autotrophic denitrification and constructed wetland microbial fuel cell to realize efficient treatment of river sewage.

[0017] The beneficial effects of the utility model relative to the prior art are:

[0018] (1) The utility model combines the constructed wetland microbial fuel cell and the sulfur autotrophic denitrification technology, realizes the double effect of pollutant removal and power generation, provides a new idea for the combination of the constructed wetland microbial fuel cell and the sulfur autotrophic denitrification technology, and provides a new direction for river sewage removal.

[0019] (2) Compared with the traditional constructed wetland microbial fuel cell device for treating sewage, the utility model combines the sulfur autotrophic denitrification and the constructed wetland microbial fuel cell, detects the removal effect of pollutants through the pollutant concentration monitoring device, detects the power generation performance of the voltage monitoring device, enhances the removal of nitrogen in water by the constructed wetland microbial fuel cell through the sulfur autotrophic denitrification technology, and realizes the removal of pollutants in sewage while generating electric energy.

[0020] (3) The utility model adds the fuel cell on the basis of the conditions of the constructed wetland. Since the constructed wetland itself has the oxygen-consuming and anaerobic area, the fuel cell is provided with a natural potential difference, that is, the oxygen-consuming reaction stage and the anaerobic reaction stage are provided for the fuel cell. Moreover, the wetland fuel cell does not need ion exchange membrane, and the cost is lower than that of the fuel cell. Compared with the fuel cell, the wetland microbial fuel cell has more application scenarios, more types of pollutants are removed, and the microbial richness of the microbial fuel cell is increased. The river sewage is difficult to achieve deep removal due to the large flowability and low pollution degree, and the nitrogen content is high. The traditional river has low nitrogen removal effect. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic view of the sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell sewage treatment system.

[0022] Figure 2 The test results of CODcr, TN, TP, NH4 + -N, NO3 - -N of the riverway water treated by the sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell wastewater treatment system of the wastewater treatment system of the embodiment 1.

[0023] Figure 3 The test results of the voltage under the treatment of the riverway water by the sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell wastewater treatment system of the wastewater treatment system of the embodiment 1.

[0024] Figure 4 The power density and polarization curve of the sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell wastewater treatment system of the wastewater treatment system of the embodiment 1.

[0025] Figure 1 The reference signs in the drawings: 1. wastewater barrel, 2. peristaltic pump, 3. water pipe, 4. water inlet, 5. gravel water distribution layer, 6. granular activated carbon anode layer, 7. anode, 8. sulfur autotrophic denitrification filter material layer, 9. intermediate gravel layer, 10. cathode, 11. granular activated carbon cathode layer, 12. wetland plant layer, 13. water outlet, 14. wire, 15. resistor. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application. Figure 1 The present application is described in detail as follows: a sulfur autotrophic denitrification filter material reinforced constructed wetland microbial fuel cell wastewater treatment system, comprising a container main body, the container main body comprises, from bottom to top, a gravel water distribution layer 5, a granular activated carbon anode layer 6, a sulfur autotrophic denitrification filter material layer 8, an intermediate gravel layer 9, a granular activated carbon cathode layer 11 and a wetland plant layer 12, an anode 7 is embedded in the granular activated carbon anode layer 6, a cathode 10 is embedded in the granular activated carbon cathode layer 11, a wire 14 penetrates through the granular activated carbon anode layer 6 and the granular activated carbon cathode layer 11 to connect the anode 7 and the cathode 10, a water inlet 4 is arranged on the gravel water distribution layer 5, and a water outlet 13 is arranged on the wetland plant layer 12.

[0028] In one embodiment, a resistor 15 is arranged in the wire 14 connecting the anode 7 and the cathode 10.

[0029] In one embodiment, one end of the water inlet 4 is connected with the peristaltic pump 2 and the wastewater bucket 1 through the water pipe 3.

[0030] In one embodiment, the anode 7 and the cathode 10 are made of activated carbon particles wrapped with a stainless steel mesh, and the mesh is 12 mesh.

[0031] In one embodiment, the particle size of the gravel water distribution layer 5 is 30-50 mm, the particle size of the intermediate gravel layer 9 is 10-20 mm, the particle size of the granular activated carbon anode layer 6 is 3-5 mm, the particle size of the sulfur autotrophic denitrification filter material layer 8 is 3-5 mm, and the particle size of the granular activated carbon cathode layer 11 is 3-5 mm.

[0032] In one embodiment, the thickness of the gravel water distribution layer 5 is 15-25 cm, the thickness of the granular activated carbon anode layer 6 is 5-8 cm, the thickness of the sulfur autotrophic denitrification filter material layer 8 is 5-8 cm, the thickness of the intermediate gravel layer 9 is 15-25 cm, and the thickness of the granular activated carbon cathode layer 11 is 5-8 cm.

[0033] In one embodiment, the container body is a cylinder with a diameter not less than 200 mm.

[0034] In one embodiment, the thickness ratio of the gravel water distribution layer 5, the granular activated carbon anode layer 6, the sulfur autotrophic denitrification filter material layer 8, the intermediate gravel layer 9, and the granular activated carbon cathode layer 11 is 3:1:1:3:1.

[0035] Embodiment 1

[0036] A sulfur autotrophic denitrification constructed wetland microbial fuel cell, the container body is a single-layer cylindrical barrel, the bottom of the barrel is provided with a water inlet 4, the top side wall is provided with a water outlet 13, the diameter of the water inlet 4 and the water outlet 13 is 20 mm, and the inner barrel is sequentially provided from bottom to top with a gravel water distribution layer 5, a granular activated carbon anode layer 6, a sulfur autotrophic denitrification filter material layer 8, an intermediate gravel layer 9, a granular activated carbon cathode layer 11, and a wetland plant layer 12, the anode 7 is buried in the granular activated carbon anode layer 6, the cathode 10 is buried in the granular activated carbon cathode layer 11, the lead wire 14 is connected with the cathode 10, and the lead wire 14 is connected with the anode 7 through the resistor 15.

[0037] The gravel water distribution layer 5 is composed of gravel with a particle size of 30-50mm and a height of 15cm; the granular activated carbon anode layer 6 and the granular activated carbon cathode layer 11 are composed of granular activated carbon with a particle size of 3-5mm and 12-mesh stainless steel mesh, both with a height of 5cm; the sulfur autotrophic denitrification filter media layer 8 is composed of sulfur autotrophic denitrification filter media with a particle size of 3-5mm and a height of 5cm; the intermediate gravel layer 9 is composed of gravel with a particle size of 10-20mm and a height of 15cm; the wetland plant layer 12 above the cathode 10 is planted with canna lilies, with a planting density of 10-20 plants per m². -2 .

[0038] The electrodes of the anode 7 and cathode 10 are composed of stainless steel mesh and granular activated carbon. The copper wire 14 is coated with epoxy resin at the connection point with the electrodes of the anode 7 and cathode 10 to avoid direct contact between the interface and the water body during operation and to avoid short circuit. The microorganisms mainly attach to the electrodes of the anode 7 and cathode 10 and the sulfur autotrophic denitrification filter media layer.

[0039] The surface of this device is covered with black cloth for a dark treatment to prevent algae growth, which would affect the device's processing efficiency.

[0040] During system operation, peristaltic pump 2 draws water from artificially simulated wastewater tank 1 through inlet 4. The water then flows through gravel distribution layer 5, granular activated carbon anode layer 6, sulfur autotrophic denitrification filter media layer 8, intermediate gravel layer 9, and granular activated carbon cathode layer 11, forming a vertical upflow operation mode. Plants are planted on top of granular activated carbon cathode layer 11, and the hydraulic retention time is set to 3 days to remove pollutants from the river water and generate electricity.

[0041] Application testing:

[0042] Wastewater treatment was carried out using the sulfur autotrophic denitrifying constructed wetland microbial fuel cell system of Example 1. The removal efficiency of pollutants and power generation of the sulfur autotrophic denitrifying constructed wetland microbial fuel cell unit of the wastewater treatment system were tested.

[0043] Tests were conducted on the pollutant removal efficiency and power generation effect of the sulfur autotrophic denitrification constructed wetland microbial fuel cell unit in the wastewater treatment system of Example 1.

[0044] Experimental methods

[0045] The sulfur-autotrophic denitrification constructed wetland microbial fuel cell device was started for wastewater treatment, removing river wastewater (with tested values ​​of COD 50 mg / L, TN 6 mg / L, TP 1 mg / L, and NH4+). + -N 3mg / L, NO3 --N 3mg / L) is introduced from the inlet of the main body of the sulfur autotrophic denitrification constructed wetland microbial fuel cell. Domestic sewage flows sequentially through the gravel distribution layer 5, the granular activated carbon anode layer 6, the sulfur autotrophic denitrification filter media layer 8, the intermediate gravel layer 9, and the granular activated carbon cathode layer 11. At the anode 7, microorganisms decompose organic matter, releasing electrons and protons. Electrons are conducted to the cathode 10 through the external circuit, forming an electric current. After purification, the sewage flows out from the top effluent 13 on one side of the constructed wetland main body. The test was conducted at the following inlet concentrations: COD 50mg / L, TN 6mg / L, TP 1mg / L, NH4+ 4mg / L. + -N 3mg / L, NO3 - -N concentration of 3 mg / L, HRT=3d, effects on CODcr, TN, TP, NH4+. + -N, NO3 - The removal rate of -N was measured over a period of 60 days. The power generation voltage of the sulfur autotrophic denitrification constructed wetland microbial fuel cell device was tested. The maximum power density and open-circuit voltage of the device were determined by changing the resistance value of the external resistor.

[0046] Figure 2 COD, TN, TP, NH4 + -N, NO3 - -N removal rate test results: influent concentrations COD 50 mg / L, TN 6 mg / L, TP 1 mg / L, NH4+ + -N 3mg / L, NO3 - -N concentration 3 mg / L, CODcr, TN, TP, NH4+ at HRT=3d + -N, NO3 - The average removal rates of -N were 81.1%, 79.5%, 82.2%, 76.12%, and 66.78%, respectively. Figure 3 The results of the voltage change process over time show that the device voltage gradually increases and eventually stabilizes, with an average voltage of 210mV. Figure 4 The results of plotting polarization and power density curves based on the voltage obtained by changing the external resistor value show that the maximum power density is 392.5 mW / ㎡ and the open-circuit voltage is 163.1 mV.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sulfur autotrophic denitrification filter media enhanced constructed wetland microbial fuel cell wastewater treatment system comprising a vessel body, characterized in that, The container body comprises, from bottom to top, a gravel water distribution layer (5), a granular activated carbon anode layer (6), a sulfur autotrophic denitrification filter material layer (8), an intermediate gravel layer (9), a granular activated carbon cathode layer (11) and a wetland plant layer (12), an anode (7) is embedded in the granular activated carbon anode layer (6), a cathode (10) is embedded in the granular activated carbon cathode layer (11), a wire (14) penetrates the granular activated carbon anode layer (6) and the granular activated carbon cathode layer (11) to connect the anode (7) and the cathode (10), a water inlet (4) is arranged in the gravel water distribution layer (5), and a water outlet (13) is arranged in the wetland plant layer (12).

2. The sulfur autotrophic denitrification filter media reinforced constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, An electric resistor (15) is arranged in the wire (14) connecting the anode (7) and the cathode (10).

3. The sulfur autotrophic denitrification filter media reinforced constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, One end of the water inlet (4) is connected with a peristaltic pump (2) and a wastewater bucket (1) through a water pipe (3).

4. The sulfur-autotrophic denitrification filter media reinforced constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, The anode (7) and the cathode (10) are made of activated carbon particles wrapped with stainless steel mesh.

5. The sulfur-autotrophic denitrification filter media reinforced constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, The particle size of the gravel water distribution layer (5) is 30-50 mm, the particle size of the intermediate gravel layer (9) is 10-20 mm, the particle size of the granular activated carbon anode layer (6) is 3-5 mm, the particle size of the sulfur autotrophic denitrification filter material layer (8) is 3-5 mm, and the particle size of the granular activated carbon cathode layer (11) is 3-5 mm.

6. The sulfur-autotrophic denitrification media enhanced constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, The thickness of the gravel water distribution layer (5) is 15-25 cm, the thickness of the granular activated carbon anode layer (6) is 5-8 cm, the thickness of the sulfur autotrophic denitrification filter material layer (8) is 5-8 cm, the thickness of the intermediate gravel layer (9) is 15-25 cm, and the thickness of the granular activated carbon cathode layer (11) is 5-8 cm.

7. The sulfur-autotrophic denitrification filter media fortified constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, The container body is a cylinder with a diameter not less than 200 mm.

8. The sulfur-autotrophic denitrification filter media fortified constructed wetland microbial fuel cell wastewater treatment system of claim 1, wherein, The thickness ratio of the gravel water distribution layer (5), the granular activated carbon anode layer (6), the sulfur autotrophic denitrification filter material layer (8), the intermediate gravel layer (9) and the granular activated carbon cathode layer (11) is 3:1:1:3:1.

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