Experimental device for researching electro-catalysis sewage denitrification

Abstract

The utility model relates to an experimental device for researching electro-catalysis sewage denitrification, which comprises a cylindrical main processor, a reference electrode, a counter electrode and a working electrode, the reference electrode, the counter electrode and the working electrode are arranged in the main processor, a water inlet is arranged at the bottom of the main processor and is used for inputting sewage, and a water outlet is arranged at the top of the main processor and is used for discharging the sewage; the working electrode is connected with a cathode of an external power supply of the main processor, the counter electrode is connected with an anode of the external power supply, and the reference electrode is connected with the anode of the power supply when the concentration of nitrate and nitrite nitrogen in the main processor is detected; the working electrode is a composite carbon felt loaded with a catalyst, and the composite carbon felt is spirally wound by taking the circle center of the main processor as the center and is uniformly distributed in the main processor; the composite carbon felt comprises a plant layer and three-dimensional carbon felts on the two sides of the plant layer, and catalysts are loaded on the plant layer and the three-dimensional carbon felts and used for converting nitrate in sewage into ammonia nitrogen and nitrite through electro-catalysis.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrocatalytic sewage denitrification, and particularly relates to an experimental device for studying electrocatalytic sewage denitrification. Background Technique

[0002] In the field of sewage treatment, denitrification treatment is a very important step, which can effectively reduce the inorganic nitrogen in sewage and avoid water eutrophication. The nitrogen in sewage mainly exists in the form of nitrate. The anaerobic ammonium oxidation process is a biological denitrification method, which has the advantages of low energy consumption, low sludge production, and no need for external organic carbon source. The nitrate nitrogen in sewage is converted into ammonia nitrogen and nitrite nitrogen, and then the ammonia nitrogen and nitrite nitrogen react through anaerobic ammonium oxidizing bacteria to obtain nitrogen gas, so as to achieve the purpose of denitrification. Obtaining ammonia nitrogen and nitrite nitrogen with a suitable molar ratio is beneficial to improving the denitrification performance of the anaerobic ammonium oxidation process. At present, how to control the conversion of nitrate nitrogen in sewage into ammonia nitrogen and nitrite nitrogen with a specific molar ratio is a difficult problem, and there are few experimental devices that can be used for research in this regard, which is not conducive to the development of anaerobic ammonium oxidation technology. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is that there are many devices for studying the overall process of anaerobic ammonium oxidation, but there are few experimental devices for studying the conversion of nitrate nitrogen in sewage into ammonia nitrogen and nitrite nitrogen, which is not conducive to the development of anaerobic ammonium oxidation technology.

[0004] The utility model provides an experimental device for studying electrocatalytic sewage denitrification, which includes a cylindrical main processor and a reference electrode, a counter electrode and a working electrode inside the main processor. The bottom of the main processor is provided with a water inlet for inputting sewage, and the top of the main processor is provided with a water outlet for discharging sewage;

[0005] The working electrode is connected to the cathode of the external power supply of the main processor, the counter electrode is connected to the anode of the external power supply, and when detecting the concentrations of nitrate and nitrite nitrogen in the main processor, the reference electrode is connected to the anode of the power supply; the working electrode is a composite carbon felt loaded with a catalyst, and the composite carbon felt is wound in a spiral shape with the center of the main processor as the center and is evenly distributed in the main processor;

[0006] The composite carbon felt includes a plant layer and three-dimensional carbon felts on both sides of the plant layer, and the plant layer and the three-dimensional carbon felts are both loaded with a catalyst for electrocatalytically converting nitrate in sewage into ammonia nitrogen and nitrite.

[0007] Optionally, the main processor is vertical, that is, the central axis of the main processor is vertical, and the outer side surface of the main processor is provided with a jacket for inputting hot water into the jacket to provide temperature guarantee for the reaction of the main processor;

[0008] The jacket has an inlet at the bottom and an outlet at the top. The inlet and the outlet are connected to an external water bath through a water pipe.

[0009] Optionally, a detachable cover is provided at the top of the main processor. There are a water outlet and three through holes on the cover. The three through holes are used to allow the wires of the reference electrode, the counter electrode, and the working electrode to pass through the main processor.

[0010] Optionally, the water inlet of the main processor is connected to a raw water tank which stores the sewage to be treated; the water outlet of the main processor is connected to a product water tank which stores the treated product water.

[0011] Optionally, the composite carbon felt is in sheet form, including a first three-dimensional carbon felt, a plant layer, and a second three-dimensional carbon felt. The three have the same size. Fine metal wires are provided on the outer sides of the first three-dimensional carbon felt and the second three-dimensional carbon felt for binding and fixing the composite carbon felt.

[0012] Further optionally, the first three-dimensional carbon felt and the second three-dimensional carbon felt have the same thickness, both being 2 - 10 mm; the thickness of the plant layer is less than that of the three-dimensional carbon felt, and the thickness of the plant layer is 1 - 5 mm.

[0013] Optionally, the composite carbon felt is vertically placed in the main processor. The head end of the composite carbon felt is close to the central axis of the main processor, and the tail end is spirally wound along the circumference of the main processor and towards the inner wall of the main processor. The tail end of the composite carbon felt is close to but does not touch the inner wall of the main processor;

[0014] The layer spacing between the adjacent inner and outer layers of the spiral composite carbon felt is equal.

[0015] Further optionally, the bottom of the composite carbon felt is close to but does not touch the bottom of the main processor, and the top of the composite carbon felt is close to but does not touch the cover of the main processor.

[0016] Further optionally, the space between the tail end of the composite carbon felt and the adjacent inner composite carbon felt corresponds to the water inlet, so that most of the sewage input from the water inlet can enter the above space, and then flow inward and upward along the spiral composite carbon felt until it is discharged from the water outlet.

[0017] The experimental device for studying electrocatalytic sewage denitrification according to the present utility model has the following beneficial effects:

[0018] (1) Using the electrocatalytic method to study the reaction of nitrate to generate ammonia nitrogen and nitrite nitrogen is simple and direct. The concentration of the generated ammonia nitrogen and nitrite nitrogen can be directly obtained. The main processor, as the main place for treating sewage, accommodates the reference electrode, the counter electrode, and the working electrode inside, and can implement the electrocatalytic method;

[0019] (2) The working electrode is a composite carbon felt loaded with a catalyst. The composite carbon felt includes a plant layer and three-dimensional carbon felts on both sides of the plant layer, which increases the catalyst loading amount and improves the reaction efficiency. Coupled with the spiral shape of the composite carbon felt, the contact efficiency between the sewage and the catalyst is increased. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of the experimental device for studying electrocatalytic sewage denitrification;

[0021] Figure 2 is a three-dimensional schematic diagram of the main processor;

[0022] Figure 3 is a top view schematic diagram of the main processor;

[0023] Figure 4 is a side view schematic diagram of the composite carbon felt.

[0024] In the drawings, 1 - main processor, 2 - reference electrode, 3 - counter electrode, 4 - composite carbon felt, 5 - power supply, 6 - water inlet, 7 - water outlet, 8 - plant layer, 9 - first three-dimensional carbon felt, 10 - second three-dimensional carbon felt, 11 - jacket, 12 - cover, 13 - original water tank, 14 - product water tank. Detailed Embodiments

[0025] This embodiment provides an experimental device for studying electrocatalytic sewage denitrification, as Figures 1 - 4 shown, which includes a cylindrical main processor 1 and a reference electrode 2, a counter electrode 3 and a working electrode inside the main processor 1. A water inlet 6 is provided at the bottom of the main processor 1 for inputting sewage, and a water outlet 7 is provided at the top of the main processor 1 for discharging sewage;

[0026] The working electrode is connected to the cathode of an external power supply 5 of the main processor 1, the counter electrode 3 is connected to the anode of the external power supply. When detecting the concentrations of nitrate and nitrite nitrogen in the main processor 1, the reference electrode 2 is connected to the anode of the power supply; the working electrode is a composite carbon felt 4 loaded with a catalyst, and the composite carbon felt 4 is wound in a spiral shape with the center of the main processor 1 as the center and is evenly distributed inside the main processor 1;

[0027] The composite carbon felt 4 includes a plant layer 8 and three-dimensional carbon felts on both sides of the plant layer 8. Catalysts are loaded on both the plant layer 8 and the three-dimensional carbon felts for electrocatalytically converting nitrate in sewage into ammonia nitrogen and nitrite.

[0028] Optionally, the main processor 1 is vertical, that is, the central axis of the main processor 1 is vertical. A jacket 11 is provided on the outer side of the main processor 1 for inputting hot water into the jacket 11 to provide temperature guarantee for the reaction of the main processor 1;

[0029] The bottom of the jacket 11 is provided with an inlet, and the top is provided with an outlet. The inlet and the outlet are connected to an external water bath through a water pipe.

[0030] Optionally, a detachable cover 12 is provided on the top of the main processor 1. The cover 12 is provided with a water outlet 7 and three through holes. The three through holes are used to allow the wires of the reference electrode 2, the counter electrode 3, and the working electrode to pass through the main processor 1.

[0031] Optionally, the water inlet 6 of the main processor 1 is connected to the original water tank 13, and the original water tank 13 stores the sewage to be treated; the water outlet 7 of the main processor 1 is connected to the product water tank 14, and the product water tank 14 stores the treated product water.

[0032] Taking a sample from the product water tank 14 and using the existing detection method, the concentrations of ammonia nitrogen and nitrite nitrogen in the product water can be obtained.

[0033] Optionally, the composite carbon felt 4 is in sheet form, including a first three-dimensional carbon felt 9, a plant layer 8, and a second three-dimensional carbon felt 10. The three have the same size. Fine metal wires are provided on the outer sides of the first three-dimensional carbon felt 9 and the second three-dimensional carbon felt 10 for tying and fixing the composite carbon felt 4. The fine metal wires can also play a role similar to that of a needle and thread, passing through the composite carbon felt 4 to prevent the relative sliding of the above three-layer structure.

[0034] Further optionally, the first three-dimensional carbon felt 9 and the second three-dimensional carbon felt 10 have the same thickness, both being 2 - 10 mm; the thickness of the plant layer 8 is less than that of the three-dimensional carbon felt, and the thickness of the plant layer 8 is 1 - 5 mm.

[0035] Further optionally, the material of the plant layer 8 is the roots, stems, and leaves of herbaceous plants. The roots, stems, and leaves of the herbaceous plants are crushed to 0.4 - 0.7 cm to obtain plant debris; then the plant debris is evenly spread to the size of the plant layer 8 and subjected to double-sided hot pressing so that the plant debris are bonded to each other to form an integral plant layer 8. The plant layer 8 has a large specific surface area, effectively increasing the catalyst loading amount. After hot pressing, the plant layer 8 becomes an integral body, reducing the loss of the catalyst, ensuring the parallelism of each experiment. The plant layer 8 has good toughness, increasing the service life of the composite carbon felt 4.

[0036] Further optionally, a mesh cover formed by a layer of fine metal mesh is covered on the outside of the plant layer after hot pressing to further fix and maintain the shape of the plant layer.

[0037] Further optionally, the plant layer 8, the first three-dimensional carbon felt 9, and the second three-dimensional carbon felt 10 are respectively immersed in a solution containing a catalyst to load the catalyst; the catalyst is an existing carbon-based metal catalyst, that is, a catalyst formed by loading iron and copper metals on activated carbon. The first three-dimensional carbon felt 9 and the second three-dimensional carbon felt 10 are the same.

[0038] Optionally, the composite carbon felt 4 is vertically placed inside the main processor 1. The head end of the composite carbon felt 4 is close to the central axis of the main processor 1, and the tail end is spirally wound along the circumference of the main processor 1 and towards the inner wall of the main processor 1. The tail end of the composite carbon felt 4 is close to but does not touch the inner wall of the main processor 1;

[0039] The layer spacing between the adjacent inner and outer layers of the spiral composite carbon felt 4 is equal.

[0040] Further optionally, the bottom of the composite carbon felt 4 is close to but does not touch the bottom of the main processor 1, and the top of the composite carbon felt 4 is close to but does not touch the cover 12 of the main processor 1.

[0041] Further optionally, the space between the tail end of the composite carbon felt 4 and the adjacent inner composite carbon felt 4 corresponds to the water inlet 6, so that most of the sewage input from the water inlet 6 can enter the above space, and then flow inward and upward along the spiral composite carbon felt 4 until it is discharged from the water outlet 7.

[0042] Optionally, the counter electrode 3 is a metal rod, such as a carbon rod or a stainless steel rod; the reference electrode 2 is a saturated calomel electrode (SCE);

[0043] The counter electrode and the reference electrode are vertically inserted into the main processor. The working electrode, the counter electrode, and the reference electrode do not contact each other.

[0044] During the experiment, the sewage in the original water tank 13 is input into the bottom of the main processor 1 through the water inlet 6. The sewage flows inward and upward along the spiral composite carbon felt 4. At the same time, an external power supply applies a voltage to the composite carbon felt 4 and the counter electrode 3 for an electrocatalytic reaction, so that the nitrate in the sewage is converted into ammonia nitrogen and nitrite nitrogen. When it is necessary to detect the concentrations of nitrate, nitrite nitrogen, and ammonia nitrogen in the sewage, the reference electrode 2 is connected to the anode of the power supply (when measuring the concentration, the voltage mode is used, and the reference electrode is required to calibrate the voltage, so the reference electrode needs to be connected; when not measuring the concentration, the constant current mode is adopted, and only the counter electrode and the working electrode are needed). The produced water flows into the produced water tank 14 for convenient sampling and detection.

[0045] By controlling the magnitude of the applied voltage and the electrolysis time during each experiment through the power supply, detecting the concentrations of ammonia nitrogen and nitrite nitrogen in the produced water, and studying the effects of different voltages and electrolysis times on the concentrations of the produced ammonia nitrogen and nitrite nitrogen, it helps to find suitable voltages and electrolysis times.

Claims

1. An experimental device for studying electrocatalytic wastewater denitrification, characterized in that: It includes a cylindrical main processor and a reference electrode, a counter electrode and a working electrode inside the main processor. The bottom of the main processor is provided with a water inlet for inputting sewage, and the top of the main processor is provided with a water outlet for discharging sewage. The working electrode is connected to the cathode of the external power supply of the main processor, the counter electrode is connected to the anode of the external power supply, and when detecting the concentration of nitrate and nitrite nitrogen in the main processor, the reference electrode is connected to the anode of the power supply; the working electrode is a composite carbon felt loaded with a catalyst, and the composite carbon felt is spirally wound around the center of the main processor and evenly distributed in the main processor; The composite carbon felt comprises a plant layer and three-dimensional carbon felt on both sides of the plant layer. The plant layer and the three-dimensional carbon felt are both loaded with catalysts for electrocatalytically converting nitrate in sewage into ammonia nitrogen and nitrite.

2. The experimental device for studying electrocatalytic wastewater denitrification according to claim 1, characterized in that: The main processor is vertical, the central axis of the main processor is vertical, and a jacket is provided on the outer side of the main processor for inputting hot water into the jacket to provide temperature guarantee for the reaction of the main processor; An inlet is arranged at the bottom of the jacket, and an outlet is arranged at the top, and the inlet and the outlet are connected to an external water bath tank through water pipes.

3. The experimental device for studying electrocatalytic wastewater denitrification according to claim 1, characterized in that: The top of the main processor is provided with a detachable cover, on which a water outlet and three through holes are provided. The three through holes are used to allow the wires of the reference electrode, the counter electrode and the working electrode to pass through the main processor.

4. The experimental device for studying electrocatalytic wastewater denitrification according to claim 1, characterized in that: The water inlet of the main processor is connected to the raw water tank, in which the sewage to be treated is stored; the water outlet of the main processor is connected to the production water tank, in which the treated production water is stored.

5. The experimental device for studying electrocatalytic wastewater denitrification according to claim 1, characterized in that: The composite carbon felt is in sheet form and includes a first three-dimensional carbon felt, a plant layer and a second three-dimensional carbon felt, which have the same size. Fine metal wires are arranged on the outside of the first three-dimensional carbon felt and the second three-dimensional carbon felt for binding and fixing the composite carbon felt.

6. The experimental device for studying electrocatalytic wastewater denitrification according to claim 5, characterized in that: The thickness of the first three-dimensional carbon felt and the second three-dimensional carbon felt are the same, both of which are 2-10 mm; the thickness of the plant layer is less than the thickness of the three-dimensional carbon felt, and the thickness of the plant layer is 1-5 mm.

7. The experimental device for studying electrocatalytic wastewater denitrification according to claim 6, characterized in that: The composite carbon felt is vertically placed in the main processor, the head end of the composite carbon felt is close to the central axis of the main processor, the tail end is spirally wound along the circumference of the main processor and toward the inner wall of the main processor, and the tail end of the composite carbon felt is close to but does not touch the inner wall of the main processor; The interlayer spacings between inner and outer adjacent layers of the spiral composite carbon felt are equal.

8. The experimental device for studying electrocatalytic wastewater denitrification according to claim 7, characterized in that: The bottom of the composite carbon felt is close to but not in contact with the bottom of the main processor, and the top of the composite carbon felt is close to but not in contact with the cover of the main processor.

9. The experimental device for studying electrocatalytic wastewater denitrification according to claim 8, characterized in that: The space between the tail end of the composite carbon felt and the adjacent inner composite carbon felt corresponds to the water inlet, so that most of the sewage input from the water inlet can enter the above space, and then flow inward and upward along the spiral composite carbon felt until it is discharged from the water outlet.

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