Three-dimensional electrolysis system suitable for treating low-carbon-nitrogen-ratio high-ammonia-nitrogen domestic sewage

Abstract

The utility model discloses a three-dimensional electrolysis system suitable for treating domestic sewage with low carbon nitrogen ratio and high ammonia nitrogen. The three-dimensional electrolysis system comprises an underground sewage regulating tank, a three-dimensional electrochemical reactor, a sedimentation tank, a submersible sewage pump, a NaCl adding device, an iron carbon powder adding device, a flocculating agent adding device, a backwashing system and an aeration system, the underground sewage regulating tank, the three-dimensional electrochemical reactor and the sedimentation tank are sequentially connected through a sewage inlet pipeline; the submersible sewage pump is arranged in the underground sewage adjusting tank; the NaCl adding device, the iron carbon powder adding device, the flocculating agent adding device and the backwashing system are respectively connected with the sewage inlet pipeline through pipelines; the aeration system comprises aerators which are uniformly arranged at the bottom of the three-dimensional electrochemical reactor. The three-dimensional electrolysis system suitable for treating the low-carbon-nitrogen-ratio high-ammonia-nitrogen domestic sewage is reasonable in structure, pollutants such as total phosphorus and SS (suspended solids) in the sewage can be effectively removed, effluent can reach the standard to be discharged after being subjected to simple biochemical treatment, and the operation cost is greatly reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of water treatment, and particularly relates to a three-dimensional electrolysis system suitable for treating domestic sewage with low carbon-nitrogen ratio and high ammonia nitrogen. Background Art

[0002] In recent years, my country's economic and social development has reached a critical period, and the contradiction between the ecological environment and carrying pressure, resource demand, etc. has become increasingly prominent. These policies have effectively promoted sewage treatment and utilization, and continuously raised the requirements for sewage treatment and discharge standards. Domestic sewage with high organic matter concentration but low carbon and nitrogen ratios and high nitrogen pollutant concentrations, as one of them, deserves much attention.

[0003] At present, the methods for treating high-concentration ammonia nitrogen wastewater include: chemical precipitation, breakpoint chlorination, catalytic oxidation, biological method, etc. The chemical precipitation method has good removal effect and can form compound fertilizer magnesium ammonium phosphate, but the treatment cost is high and it is easy to cause secondary pollution of residual phosphorus; the stripping method is currently a commonly used physical and chemical denitrification technology, but there are problems such as frequent scaling of the stripping tower, low ammonia nitrogen removal efficiency at low temperature, and secondary pollution of the stripping gas: the breakpoint chlorination method has high denitrification efficiency, but the by-products chloramine and chlorinated organic matter are easy to cause secondary pollution; the catalytic oxidation method has high purification efficiency, but the catalyst is easy to lose and the equipment is easy to corrode; the chemical precipitation method, breakpoint chlorination method, and catalytic oxidation method are suitable for industrial wastewater treatment, but it is difficult to apply them on a large scale in domestic wastewater treatment; the traditional biological method is only suitable for treating low-concentration ammonia nitrogen wastewater. When treating low-carbon-nitrogen ratio high-concentration ammonia nitrogen wastewater, total nitrogen and other factors are easy to exceed the standard, and a large amount of external carbon source needs to be added for denitrification and denitrification, and the operating cost is high. Summary of the invention

[0004] The purpose of the utility model is to provide a three-dimensional electrolysis system suitable for treating domestic sewage with low carbon-nitrogen ratio and high ammonia nitrogen. The system has a reasonable structure and can effectively remove pollutants such as total phosphorus and SS in sewage. The effluent can meet the discharge standards after simple biochemical treatment, which greatly reduces the operating cost.

[0005] To achieve the above-mentioned purpose, the technical solution of the utility model is to design a three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage, including an underground sewage regulating tank, a three-dimensional electrochemical reactor, a sedimentation tank, a submersible sewage pump, a NaCl dosing device, an iron-carbon powder dosing device, a flocculant dosing device, a backwashing system and an aeration system;

[0006] The underground sewage regulating tank, the three-dimensional electrochemical reactor and the sedimentation tank are connected in sequence through a sewage inlet pipeline;

[0007] The submersible sewage pump is arranged in an underground sewage regulating tank;

[0008] The NaCl dosing device, the iron-carbon powder dosing device and the backwashing system are respectively connected to the sewage inlet pipeline between the underground sewage regulating tank and the three-dimensional electrochemical reactor through pipelines;

[0009] The flocculant dosing device is connected to the sewage inlet pipeline between the three-dimensional electrochemical reactor and the sedimentation tank through a pipeline;

[0010] The top of the anode end of the three-dimensional electrochemical reactor is provided with an exhaust port, the top of the cathode end of the three-dimensional electrochemical reactor is provided with a water outlet and a sampling port, and the bottom of the cathode end is provided with an emptying and draining port;

[0011] The aeration system comprises aerators uniformly arranged at the bottom of the three-dimensional electrochemical reactor.

[0012] Preferably, anode plates and cathode plates are cross-arranged in the three-dimensional electrochemical reactor, the anode plates and cathode plates are electrically connected to the electrolysis power supply, the anode plates are made of titanium-based ruthenium-iridium coating, and the cathode plates are titanium electrodes.

[0013] Preferably, the three-dimensional electrochemical reactors are arranged in two groups in parallel, and each group is composed of two three-dimensional electrochemical reactors connected in series.

[0014] Preferably, the three-dimensional electrolysis system suitable for treating domestic sewage with low carbon-nitrogen ratio and high ammonia nitrogen also includes a reflux system, which includes a sewage reflux pipeline, and the water outlet end of the three-dimensional electrochemical reactor is connected to the sewage inlet pipeline through the sewage reflux pipeline.

[0015] Preferably, the reflux system further comprises an iron-carbon powder reflux pipeline, and the sedimentation tank is connected to the sewage inlet pipeline via the iron-carbon powder reflux pipeline.

[0016] Preferably, the pipelines connecting the NaCl dosing device and the flocculant dosing device are respectively connected to the sewage inlet pipeline through a pipeline mixer.

[0017] The advantages and beneficial effects of the utility model are: providing a three-dimensional electrolysis system suitable for treating low-carbon-nitrogen ratio and high-ammonia nitrogen domestic sewage, which has a reasonable structure and can effectively remove pollutants such as total phosphorus and SS in sewage, and the effluent can meet the discharge standards after simple biochemical treatment, greatly reducing the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the utility model.

[0019] Figure 2 It is a schematic diagram of a three-dimensional electrochemical reactor in the utility model. DETAILED DESCRIPTION

[0020] The following is a further description of the specific implementation of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0021] The technical solution specifically implemented in this utility model is:

[0022] like Figure 1 and Figure 2 As shown, a three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage comprises an underground sewage regulating tank 1, a three-dimensional electrochemical reactor 2, a sedimentation tank 3, a submersible sewage pump 4, a NaCl dosing device 5, an iron-carbon powder dosing device 6, a flocculant dosing device 7, a backwashing system 8 and an aeration system 9;

[0023] The underground sewage regulating tank 1, the three-dimensional electrochemical reactor 2 and the sedimentation tank 3 are connected in sequence through a sewage inlet pipeline 10;

[0024] The submersible sewage pump 4 is arranged in the underground sewage regulating tank 1;

[0025] The NaCl dosing device 5, the iron-carbon powder dosing device 6 and the backwashing system 8 are respectively connected to the sewage inlet pipeline 10 between the underground sewage regulating tank 1 and the three-dimensional electrochemical reactor 2 through pipelines;

[0026] The flocculant dosing device 7 is connected to the sewage inlet pipeline 10 between the three-dimensional electrochemical reactor 2 and the sedimentation tank 3 through a pipeline, and the pipeline connecting the NaCl dosing device 5 and the flocculant dosing device 7 is connected to the sewage inlet pipeline 10 through a pipeline mixer 11;

[0027] The top of the anode end of the three-dimensional electrochemical reactor 2 is provided with an exhaust port, the top of the cathode end of the three-dimensional electrochemical reactor 2 is provided with a water outlet and a sampling port, and the bottom of the cathode end is provided with an emptying and draining port;

[0028] The aeration system 9 includes aerators uniformly arranged at the bottom of the three-dimensional electrochemical reactor 2 .

[0029] The sewage treated by the utility model is mainly excrement and flushing water from large public toilets, among which the flushing water is mainly recycled water after sewage treatment, resulting in a high NH3-N concentration in the sewage in the underground sewage regulating tank, which can reach 150 mg / L, while the C / N in the sewage is relatively low, making it difficult to achieve the coordinated removal of NH3-N and organic matter and stable compliance with standards.

[0030] The utility model adopts the above technical means to adjust the addition amount of 10% NaCl solution in the pipeline mixer 11 on the sewage inlet pipeline 10 by adjusting the rotation speed value of the dosing pump of the NaCl dosing device 5, and mixes it with the raw sewage in the pipeline mixer 11. The carbon-nitrogen ratio of the raw sewage is 1-3, NH4 + -N concentration can reach 150mg / L. After passing through the three-dimensional electrochemical reactor, the ammonia nitrogen removal rate is ≥70%, and the carbon-nitrogen ratio is 3-6. The three-dimensional electrochemical reactor 2 is the main reaction equipment of this system. The three-dimensional electrochemical reactor 2 is in the form of a tube. The sewage flows through the three-dimensional electrochemical reactor 2 from bottom to top. After power is turned on, the pollutants in the water can be removed by redox reaction. The aerator is evenly installed at the bottom of the reactor for stirring and backwashing. The bottom is equipped with a venting outlet, which is connected to the pipeline for regular discharge. In addition, iron-carbon powder is added as the third electrode, the particle size is 100 mesh, the iron-carbon ratio is 1-3, and the dosage is 200-400g / L. The iron-carbon powder is added non-continuously. After one addition, it is recycled in the electrolytic cell. It is discharged and added again according to the usage and pollution degree. Part of the added iron powder is oxidized to trivalent iron, and the effluent is fed to the sedimentation tank 3 for coagulation and sedimentation after adding flocculants, which can effectively remove pollutants such as total phosphorus and SS in the sewage, with a total phosphorus removal rate of ≥90%. After treatment by the three-dimensional electrolysis system, some indicators have passed the standard, and after simple biochemical treatment, the discharge can meet the standard, saving more than 30% of the operating cost. In addition, the backwash system 8 can be used to add 5%-10% citric acid solution to the reactor for backwashing and aeration appropriately to increase the backwashing intensity and reduce the backwashing time. After the backwashing is completed, it is discharged through the bottom venting outlet.

[0031] Furthermore, anode plates and cathode plates are cross-arranged in the three-dimensional electrochemical reactor 2, and the anode plates and cathode plates are electrically connected to the electrolysis power supply. The material of the anode plate is a titanium-based ruthenium-iridium coating, and the cathode plate is a titanium electrode.

[0032] Furthermore, the three-dimensional electrochemical reactor 2 is arranged in two groups in parallel, each group is composed of two three-dimensional electrochemical reactors connected in series. By adopting the above scheme, the total electrolysis time is 20-40 minutes. And the backwashing can be carried out alternately, one group is running while the other group is backwashing, reducing the impact on the operating volume.

[0033] Furthermore, the three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio high ammonia nitrogen domestic sewage also includes a reflux system, and the reflux system includes a sewage reflux pipeline 12, and the outlet end of the three-dimensional electrochemical reactor 2 is connected to the sewage inlet pipeline 10 through the sewage reflux pipeline 12. By adopting the above scheme, part of the effluent is refluxed to the inlet, and the reflux ratio is 20%-100%.

[0034] Furthermore, the reflux system further includes an iron-carbon powder reflux pipeline 13, and the sedimentation tank 3 is connected to the sewage inlet pipeline 10 via the iron-carbon powder reflux pipeline 13. By adopting the above scheme, the iron-carbon powder settled in the mud bucket at the bottom of the sedimentation tank 3 is refluxed to the three-dimensional electrochemical reactor 2, and the reflux ratio is 20%-50%.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A three-dimensional electrolysis system suitable for treating domestic sewage with low carbon-nitrogen ratio and high ammonia nitrogen, characterized in that: It includes underground sewage regulating tank, three-dimensional electrochemical reactor, sedimentation tank, submersible sewage pump, NaCl dosing device, iron-carbon powder dosing device, flocculant dosing device, backwash system and aeration system; The underground sewage regulating tank, the three-dimensional electrochemical reactor and the sedimentation tank are connected in sequence through a sewage inlet pipeline; The submersible sewage pump is arranged in an underground sewage regulating tank; The NaCl dosing device, the iron-carbon powder dosing device and the backwashing system are respectively connected to the sewage inlet pipeline between the underground sewage regulating tank and the three-dimensional electrochemical reactor through pipelines; The flocculant dosing device is connected to the sewage inlet pipeline between the three-dimensional electrochemical reactor and the sedimentation tank through a pipeline; The top of the anode end of the three-dimensional electrochemical reactor is provided with an exhaust port, the top of the cathode end of the three-dimensional electrochemical reactor is provided with a water outlet and a sampling port, and the bottom of the cathode end is provided with an emptying and draining port; The aeration system comprises aerators uniformly arranged at the bottom of the three-dimensional electrochemical reactor.

2. The three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage according to claim 1 is characterized in that: Anode plates and cathode plates are cross-arranged in the three-dimensional electrochemical reactor, and the anode plates and cathode plates are electrically connected to an electrolysis power source. The anode plates are made of a titanium-based ruthenium-iridium coating, and the cathode plates are titanium electrodes.

3. The three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage according to claim 2 is characterized in that: The three-dimensional electrochemical reactors are arranged in two groups in parallel, and each group is composed of two three-dimensional electrochemical reactors connected in series.

4. The three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage according to claim 3 is characterized in that: The three-dimensional electrolysis system suitable for treating low-carbon-nitrogen ratio and high-ammonia nitrogen domestic sewage also includes a reflux system, which includes a sewage reflux pipeline. The water outlet of the three-dimensional electrochemical reactor is connected to the sewage inlet pipeline through the sewage reflux pipeline.

5. The three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage according to claim 4 is characterized in that: The reflux system further comprises an iron-carbon powder reflux pipeline, and the sedimentation tank is connected to a sewage inlet pipeline via the iron-carbon powder reflux pipeline.

6. The three-dimensional electrolysis system suitable for treating low carbon-nitrogen ratio and high ammonia nitrogen domestic sewage according to claim 1 is characterized in that: The pipelines connecting the NaCl dosing device and the flocculant dosing device are respectively connected to the sewage inlet pipeline through a pipeline mixer.

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