A method and system for carbon source self-supplying in a sewage treatment plant based on electromagnetic wave technology

Abstract

The present application belongs to the technical field of sewage treatment, and particularly relates to a method and system for self-supply of carbon source in a sewage treatment plant based on electromagnetic wave technology. The system comprises: an A / A / O reactor comprising an anaerobic tank, an anoxic tank and an aerobic tank arranged in sequence; a water inlet pipeline connected to the anaerobic tank; a secondary sedimentation tank connected to the aerobic tank, the secondary sedimentation tank having a sludge outlet; a first electromagnetic wave loading unit having a first flow channel, the two ends of the first flow channel being connected to the water inlet pipeline and the sludge outlet through sludge return pipelines respectively; and a second electromagnetic wave loading unit having a second flow channel, the two ends of the second flow channel being connected to the anoxic tank and the aerobic tank through nitrification liquid return pipelines respectively. The present application can realize in-situ release and efficient use of organic matter by synergistically loading return sludge and internal return nitrification liquid, thereby realizing self-supply of carbon source in the sewage treatment plant.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and in particular relates to a method and system for carbon source supply in wastewater treatment plants based on electromagnetic wave technology. Background Technology

[0002] The A / A / O process, as a mainstream biological nitrogen and phosphorus removal technology, effectively removes organic matter and nitrogen and phosphorus pollutants from wastewater by forming an anaerobic-anoxic-aerobic system, and is widely used in urban wastewater treatment plants. However, during operation, the system often faces a bottleneck of insufficient carbon source, leading to a decrease in denitrification efficiency.

[0003] In current engineering practice, external carbon sources are commonly used to alleviate carbon source shortages, such as sodium acetate, methanol, and glucose, to meet the electron donor requirements of denitrifying bacteria. These organic compounds are easily absorbed and utilized by denitrifying microorganisms, significantly improving nitrogen removal efficiency in the short term. However, external carbon sources are costly and require long-term continuous addition, significantly increasing the operating costs of wastewater treatment plants. It is estimated that in large wastewater treatment plants, the cost of external carbon sources can account for more than 20% of the total operating costs, becoming the third largest operational burden after energy consumption and sludge treatment. Furthermore, the carbon source addition process has low control precision, easily leading to insufficient addition affecting treatment efficiency, or excessive addition causing problems such as increased effluent COD and sludge bulking, posing potential secondary pollution risks. Therefore, exploring more economical, safe, and controllable carbon source supply strategies has become a key research focus for the optimization of current wastewater treatment technologies.

[0004] The introduction of electromagnetic wave loading technology provides a new solution for carbon self-supply. This technology leverages the high-frequency response characteristics of polar molecules under electromagnetic fields, exhibiting a significant dissolution effect in sludge treatment environments. Specifically, intracellular and intercellular water molecules in sludge undergo dipoleization and high-speed rotation under the influence of high-frequency electromagnetic waves, generating microscopic shearing and impact effects. This mechanically disrupts the cell walls of microorganisms, prompting the release of intracellular organic matter to the extracellular space, significantly increasing the content of dissolved organic matter (such as volatile fatty acids and low-molecular-weight organic acids) in the sludge supernatant. These soluble organic substances possess good bioavailability and can be directly used as electron donors for denitrification, meeting the carbon source requirements in the anoxic phase. Compared to traditional external methods, the electromagnetic wave-stimulated carbon source release process requires no external reagents, relying on the system's endogenous resources for supply and utilization. This not only effectively reduces operating costs but also enhances environmental friendliness.

[0005] Therefore, making reasonable use of the dissolution effect of electromagnetic wave technology to ensure the full release of organic matter is one of the important potential paths to achieve carbon source supply in wastewater treatment plants. Summary of the Invention

[0006] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method and system for self-supply of carbon sources in wastewater treatment plants based on electromagnetic wave technology. The inventors have discovered that by using electromagnetic waves to synergistically load returned sludge and internally returned nitrifying liquid, in-situ release and efficient utilization of organic matter can be achieved, thereby realizing self-supply of carbon sources in wastewater treatment plants.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0008] A carbon source supply system for a wastewater treatment plant based on electromagnetic wave technology, comprising:

[0009] An A / A / O reactor, comprising an anaerobic tank, an anoxic tank, and an aerobic tank connected in sequence;

[0010] The inlet pipe connecting to the anaerobic tank;

[0011] A secondary sedimentation tank connected to the aerobic tank, the secondary sedimentation tank having a sludge outlet;

[0012] The first electromagnetic wave loading unit has a first flow channel, and the two ends of the first flow channel are respectively connected to the water inlet pipe and the sludge outlet through a sludge return pipe.

[0013] And a second electromagnetic wave loading unit, which has a second flow channel, the two ends of which are connected to the anoxic tank and the aerobic tank respectively through a nitrification liquid return pipeline.

[0014] Based on the above technical solution:

[0015] The first electromagnetic wave loading unit can continuously excite the returned sludge with electromagnetic waves, which can promote the release of organic matter.

[0016] The second electromagnetic wave loading unit can continuously excite the refluxed nitrification liquid with electromagnetic waves, which can promote the release of organic matter.

[0017] The synergistic effect of activated return sludge and activated return nitrified liquor in the A / A / O reactor can significantly increase the SCOD of the return sludge and at the same time significantly improve the SCOD of the nitrified liquor supernatant.

[0018] Furthermore, a stirrer is installed inside the anaerobic tank.

[0019] Furthermore, a stirrer is installed inside the anoxic pool.

[0020] Furthermore: the aerobic tank is equipped with an aeration disc, and the aeration disc is connected to an air pump.

[0021] Furthermore, a peristaltic pump is connected between the first electromagnetic wave loading unit and the water inlet pipe.

[0022] Furthermore, a peristaltic pump is installed between the second electromagnetic wave loading unit and the anoxic pool.

[0023] Furthermore, a return pipeline for direct sludge return is provided between the secondary sedimentation tank and the inlet pipeline.

[0024] Furthermore, a return pipeline for direct reflux of nitrified liquid is provided between the aerobic tank and the anoxic tank.

[0025] This invention also provides a carbon source supply method for wastewater treatment plants based on electromagnetic wave technology, employing the aforementioned carbon source supply system for wastewater treatment plants based on electromagnetic wave technology, comprising the following steps:

[0026] 1) The wastewater was treated using an A / A / O reactor and operated stably for a period of time;

[0027] 2) A portion (10-30%, preferably 15-25%) of the sludge obtained from the secondary sedimentation tank is fed into the anaerobic tank as return sludge. The return sludge is continuously excited by electromagnetic waves, which increases the SCOD content of the supernatant of the return sludge output from the first electromagnetic wave loading unit by, for example, 910-920%, and increases the SCOD content of the subsequent return nitrification liquid by, for example, 75-85%.

[0028] 3) A portion (5-20% of the returned nitrified liquid, preferably 5-15%) of the nitrified liquid from the aerobic tank is fed into the anoxic tank as returned nitrified liquid. The returned nitrified liquid is continuously excited by electromagnetic waves to increase the SCOD content of the returned nitrified liquid output from the second electromagnetic wave loading unit, for example, by 1045-1055%, and to increase the SCOD content of the supernatant of the returned sludge from the subsequent first electromagnetic wave loading unit, for example, by 990-1000%.

[0029] Based on the above technical solution:

[0030] Continuous electromagnetic wave excitation of the returned sludge can promote the release of organic matter.

[0031] Continuous electromagnetic wave excitation of the refluxed nitrification liquid can promote the release of organic matter.

[0032] The synergistic effect of activated return sludge and activated return nitrified liquor in the A / A / O reactor can significantly increase the SCOD of the return sludge and at the same time significantly improve the SCOD of the nitrified liquor supernatant.

[0033] In the above technical solution, steps 2) to 3) can be repeated until all sewage is treated.

[0034] In the above technical solution, sludge and / or nitrification liquid that have not been subjected to electromagnetic wave loading can be recycled.

[0035] Specifically:

[0036] The power for continuous electromagnetic wave excitation of the return sludge is 240-280 W, preferably 260 W;

[0037] The duration of continuous electromagnetic wave excitation for the returned sludge is 40-50 s, preferably 45 s;

[0038] Returned sludge accounts for 15-25% of the total sludge, preferably 20%;

[0039] The frequency of continuous electromagnetic wave excitation for the return sludge is 2400-2500 MHz, preferably 2450 MHz.

[0040] Specifically:

[0041] The power of continuous electromagnetic wave excitation of the reflux nitrification liquid is 360-440 W, preferably 400 W;

[0042] The duration of continuous electromagnetic wave excitation of the reflux nitrification liquid is 70-80 s, preferably 75 s;

[0043] The reflux nitrification liquor accounts for 5-15% of the total nitrification liquor, preferably 10%;

[0044] The frequency of continuous electromagnetic wave excitation of the reflux nitrification liquid is 2400-2500 MHz, preferably 2450 MHz.

[0045] Specifically:

[0046] Electromagnetic wave continuous excitation is performed after the A / A / O reactor has been running stably for 25-35 days, preferably for 30 days.

[0047] The operating temperature is 20-30 ℃, preferably 25 ℃;

[0048] The dissolved oxygen in the aerobic tank is 1.60-1.70 mg / L, preferably 1.66 mg / L;

[0049] The sludge return ratio is 65-75%, preferably 70%;

[0050] The nitration liquor reflux ratio is 280-320%, preferably 300%;

[0051] The sludge retention time is 14-16 days, preferably 15 days.

[0052] Specifically, the residence time in the anaerobic tank is 1.8-2.2 seconds.

[0053] Specifically, the residence time in the anoxic pool is 2.8-3.2 seconds.

[0054] Specifically, the residence time in the aerobic tank is 5.6-6.0 seconds.

[0055] The beneficial effects of this invention are:

[0056] 1. This invention utilizes electromagnetic waves to synergistically load the returned sludge and internally returned nitrifying liquid. The energy radiation induces high-speed movement of intracellular and intercellular polar molecules in microorganisms, triggering cell structure rupture and releasing intracellular organic matter into the liquid phase. This significantly increases the concentration of biochemically usable dissolved organic matter in the system, thereby increasing the system's organic load. The released organic matter can be rapidly converted into low-molecular-weight organic acids in the anaerobic zone, directly serving as electron donors for denitrification, effectively supplementing carbon source supply, improving the carbon-to-nitrogen ratio imbalance, and enhancing the system's nitrogen removal efficiency.

[0057] 2. This invention employs a synergistic loading strategy, acting separately on the return sludge and the internal return nitrifying liquor. This simultaneously induces the release of intracellular high-molecular-weight organic matter in different return paths, thereby constructing a multi-point distributed, dynamically balanced carbon source supply mechanism within the system. Simultaneously, through dual-channel carbon source supply, it achieves rapid response and adjustment to load fluctuations, enhances the stability and continuity of the system's carbon source, improves the adaptability of the A / A / O process to complex operating conditions, and comprehensively optimizes carbon source efficiency, denitrification performance, and operational flexibility. It possesses significant practical value and engineering application potential.

[0058] 3. This invention achieves closed-loop regulation of extracting, releasing, and utilizing organic carbon sources from within the system, avoiding dependence on traditional chemical carbon sources, significantly reducing operating costs, and improving the green and low-carbon level of wastewater treatment plants. Simultaneously, the electromagnetic wave loading process does not involve the addition of exogenous chemical agents, exhibiting good environmental compatibility and operational safety, providing a feasible and efficient technical path for large-scale wastewater treatment plants to construct self-sufficient carbon source supply systems.

[0059] 4. It enables in-situ release and efficient utilization of organic matter, solving the technical problems of high cost, strong dependence, and difficulty in regulation of traditional carbon source replenishment methods. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the carbon source supply system for a wastewater treatment plant based on electromagnetic wave technology, as described in this invention.

[0061] Figure 2 SCOD concentration data of reflux sludge and nitrification supernatant under different operating conditions for electromagnetic wave loading.

[0062] Figure 3 The image shows the fluorescence spectral parameters of the sludge supernatant before and after electromagnetic wave loading.

[0063] Appendix Figure 1 The list of components represented by each number is as follows:

[0064] 1. Anaerobic tank, 2. Anoxic tank, 3. Aerobic tank, 4. Secondary sedimentation tank, 5. First electromagnetic wave loading unit, 6. Second electromagnetic wave loading unit. Detailed Implementation

[0065] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0066] Unless otherwise specified, the test methods in the embodiments are conventional methods; unless otherwise specified, the materials and reagents used are commercially available.

[0067] The wastewater quality indicators are: COD: 240-250 mg / L, TN: 35-40 mg / L, TP: 3.5-4 mg / L, pH: 6-8.

[0068] During the reactor start-up phase, sludge returned from the Longwangzui Wastewater Treatment Plant in Wuhan was used as inoculum sludge.

[0069] In one specific implementation, such as Figure 1 As shown, the carbon source supply system of the wastewater treatment plant based on electromagnetic wave technology includes: an A / A / O reactor, an influent pipeline, a secondary sedimentation tank 4, a first electromagnetic wave loading unit 5, and a second electromagnetic wave loading unit 6. The A / A / O reactor includes an anaerobic tank 1, an anoxic tank 2, and an aerobic tank 3, which are connected in sequence.

[0070] The inlet pipe connects to anaerobic tank 1. Secondary sedimentation tank 4 connects to aerobic tank 3, and secondary sedimentation tank 4 has a sludge outlet. The first electromagnetic wave loading unit 5 has a first flow channel, with its two ends connected to the inlet pipe and the sludge outlet respectively via sludge return pipes. The second electromagnetic wave loading unit 6 has a second flow channel, with its two ends connected to anoxic tank 2 and aerobic tank 3 respectively via nitrification liquid return pipes.

[0071] The first electromagnetic wave loading unit 5 and the second electromagnetic wave loading unit 6 can each adopt the following existing technologies: a box-type electromagnetic wave generator with a flow channel running through the box, the flow channel material being a silicone tube. The connection between the flow channel and the electromagnetic wave generator is sealed.

[0072] To ensure even mixing, a stirrer is installed in both the anaerobic tank 1 and the anoxic tank 2.

[0073] To further ensure that the returned sludge and returned nitrified liquid flow through at an appropriate speed, a peristaltic pump is installed between the first electromagnetic wave loading unit 5 and the inlet pipeline, and a peristaltic pump is installed between the second electromagnetic wave loading unit 6 and the anoxic tank 2.

[0074] In one specific implementation, the carbon source supply method for wastewater treatment plants based on electromagnetic wave technology can be implemented and verified according to the following steps:

[0075] Step 1: Set up a carbon source supply system for the wastewater treatment plant based on electromagnetic wave technology;

[0076] Step 2: By adjusting the electromagnetic wave loading conditions (loading power, loading time) and the amount of returned sludge being loaded, a comparative experiment was conducted to detect the changes in organic matter content in the sludge supernatant and nitrification liquor supernatant before and after electromagnetic wave loading of the returned sludge.

[0077] Step 3: Based on the electromagnetic wave loading of the returned sludge in Step 2, adjust the loading power, loading time and loading percentage of the electromagnetic wave loading of the nitrification liquid, and detect the change in organic matter content of the supernatant of the nitrification liquid under the condition of electromagnetic wave synergistic loading of returned sludge and nitrification liquid.

[0078] Specifically, in step one: the reactors for the anaerobic, anoxic, and aerobic sections are made of plexiglass to ensure airtightness; an inlet pump, outlet pipe, and regulating valve are installed to ensure controllable flow; stirring devices are installed in the anaerobic and anoxic zones to ensure uniform mixing; an aeration system is set up in the aerobic zone, and the gas flow rate is adjusted; and the loading frequency of the electromagnetic wave loading unit is set.

[0079] Specifically, step two includes: after the system has been running stably for 30 days, a branch pipe of the electromagnetic wave loading device is added to the return sludge pipeline, connecting the sludge inlet and outlet pipes of the continuous flow 2450 MHz electromagnetic wave loading device, and leaving a sampling port. A peristaltic pump is added to the sludge inlet pipeline, and the flow rate is adjusted by adjusting the speed of the peristaltic pump.

[0080] During the experiment, the electromagnetic wave loading power was changed by adjusting the input voltage, the loading time was changed by adjusting the branch pipe length (e.g., adjusting a straight pipe to a bend to increase the path length), and the loading percentage was changed by adjusting the peristaltic pump speed. Under the set loading conditions, the SCOD content of the supernatant of the sludge samples and the SCOD content of the nitrification liquor supernatant were measured before and after loading. Return sludge that had not undergone electromagnetic wave loading was directly returned from the secondary sedimentation tank to the front end through the original sludge return pipe.

[0081] Specifically, step three includes: based on the electromagnetic wave-loaded sludge operating condition, a continuous flow of 2450 MHz electromagnetic wave-loaded internal reflux nitrified liquid is added to the nitrified liquid return pipe of the reactor to conduct system operation tests of electromagnetic wave-loaded A / A / O internal and external reflux. During the test, the loading conditions are changed by adjusting the input voltage, branch pipe length, and peristaltic pump speed. Under the set loading conditions, the SCOD content of the supernatant of the nitrified liquid after loading is measured. The remaining nitrified liquid that has not undergone electromagnetic wave loading is directly returned from the aerobic tank to the anoxic tank through the original nitrified liquid return pipe. At the same time, sludge samples from each stage of the A / A / O process under three operating conditions—no electromagnetic wave loading, loaded sludge return, and synergistic loading internal and external reflux—are taken for three-dimensional fluorescence spectroscopy analysis.

[0082] Example

[0083] 1. The A / A / O system has a treatment capacity of 1.12 L / h and an effective volume of 10.9 L in the main reaction zone. The effective volumes of the anaerobic tank, anoxic tank, and aerobic tank are 2.2 L, 2.2 L, and 6.5 L, respectively, with hydraulic retention times of 2, 3, and 5.8 h, respectively. The effective volume of the secondary sedimentation tank is 7.0 L.

[0084] 2. The anaerobic and anoxic tanks are equipped with electric mixers, and the aerobic tank has an aeration disc at the bottom. The aeration rate is adjusted using a rotor flow meter. The anaerobic, anoxic, aerobic, and sedimentation tanks are connected by PVC pipes, and the flow of the sludge mixture is achieved by gravity difference.

[0085] 3. The test temperature was controlled at around 25℃, the DO concentration in the aerobic tank was controlled at 1.66 mg / L, the sludge return ratio was set at 70%, the nitrification liquor return ratio was set at 300%, and the sludge retention time was set at 15 days.

[0086] 4. After the system has been running stably for 30 days, the sludge and nitrification liquor will be added back.

[0087] By setting different operating parameters to run the A / A / O system, the organic load of the system can be increased. Specific information is as follows:

[0088] Experiment 1: Under operating conditions I (unloaded), II (loaded return sludge: P=260 W, T=45 s, loading percentage=20%), and III (loaded return sludge: P=260 W, T=45 s, loading percentage=20%; loaded return nitrification liquor: P=400 W, T=75 s, loading percentage=10%), the SCOD concentration of the supernatant (output of the first electromagnetic wave loading unit) and the SCOD concentration of the nitrification liquor supernatant (output of the second electromagnetic wave loading unit) in the return sludge sample were detected by the potassium dichromate method.

[0089] Experiment 2: Under operating conditions I (unloaded), II (loaded with refluxed sludge: P=260 W, T=45 s, loading percentage=20%), and III (loaded with refluxed sludge: P=260 W, T=45 s, loading percentage=20%; loaded with refluxed nitrified liquor: P=400 W, T=75 s, loading percentage=10%), the fluorescence spectra of dissolved organic matter in EPS were measured using a fluorescence spectrophotometer.

[0090] During the above experiment:

[0091] Condition I involves running the system in its initial state for 30 days without loading return sludge or return nitrification liquor, and then measuring the data and calculating the average value.

[0092] In Condition I, the data measured were from the sludge return pipe and the nitrification liquid return pipe without electromagnetic wave loading.

[0093] In Condition II, the data measured are from the sludge return pipe with electromagnetic waves applied and the nitrification liquid return pipe without electromagnetic waves applied.

[0094] In Condition III, the data measured are from the sludge return pipe and the nitrification liquid return pipe that are subjected to electromagnetic waves.

[0095] Test results:

[0096] Table 1 shows the SCOD dissolution effects of sludge supernatant and nitrification liquor supernatant before and after loading under different electromagnetic wave loading conditions.

[0097] Table 1. SCOD concentrations of return sludge and nitrification liquor supernatant under electromagnetic wave loading conditions.

[0098]

[0099] The experimental data in Table 1 show that, under operating condition II, after irradiating the 20% loaded return sludge with electromagnetic waves at a power of 260 W for 45 s, the total SCOD dissolved by the system significantly increased. After loading, the SCOD concentrations of the return sludge supernatant and nitrification liquor supernatant increased by approximately 917.86% and 80% respectively compared to the unloaded system, increasing the organic load of the A / A / O system by 2.073 kg COD / d and 0.225 kg COD / d respectively. Under the condition of loading return sludge in Operating Mode II, after irradiating the internally returned nitrified liquor with a loading percentage of 10% with electromagnetic waves for 75 seconds using electromagnetic waves with a power of 400 W in Operating Mode III, the SCOD concentrations of the return sludge supernatant and the nitrified liquor supernatant increased by approximately 996.43% and 1051.43% respectively compared to the unloaded system, increasing the organic load of the A / A / O system by 2.251 kg COD / d and 2.969 kg COD / d respectively. Compared to the system with only return sludge loaded, the SCOD concentrations of the return sludge supernatant and the nitrified liquor supernatant increased by 7.7% and 539.68% respectively, increasing the organic load of the A / A / O system by 0.177 kg COD / d and 2.743 kg COD / d respectively. This indicates that the electromagnetic wave technology, in conjunction with the loading of internal and external return sludge, effectively promotes the release of organic matter in the return sludge and nitrified liquor. (Results can be referenced.) Figure 2 .

[0100] Table 2 shows the positions and intensities of specific characteristic peaks in sludge samples before and after loading under different electromagnetic wave loading conditions.

[0101] Table 2. Fluorescence spectral parameters of sludge supernatant before and after electromagnetic wave loading.

[0102]

[0103] Tryptophan-like substances, as characteristic amino acids of proteins, are typically derived from the release of intracellular high-molecular-weight organic matter and possess good biodegradability. During the anaerobic stage, these components can be rapidly converted into small molecule compounds such as volatile fatty acids (VFAs), which are then reused by microorganisms as supplementary carbon sources in the denitrification unit. Therefore, they can be used as indicators of the dynamic process of organic carbon release in the system.

[0104] Table 2 shows that when electromagnetic wave loading was applied to the sludge recirculation, the intensity of the characteristic peak values ​​of tryptophan-like substances in the EPS of activated sludge in the three stages of the A / A / O system increased from 9494.5, 9450.8, and 9559.3 mV to 9854.7, 9854.7, and 9735.8 mV, representing increases of 360.2, 403.9, and 176.5 mV, respectively. The increase in tryptophan-like substances originates from the loosening of the sludge floc structure and the rupture of microbial cells caused by electromagnetic wave loading, leading to the release of extracellular polymeric substances (EPS) and intracellular components, thus causing the accumulation of tryptophan-like substances in the liquid phase. Compared with the system without electromagnetic wave loading, the fluorescence intensity of tryptophan-like substances in the supernatant of sludge samples from the anoxic and aerobic tanks increased by 5% and 3.81%, respectively, due to electromagnetic wave synergistic loading and recirculation. This indicates that electromagnetic wave synergistic loading and recirculation effectively promote the release of organic matter in the sludge. (See results for reference.) Figure 3 .

[0105] Based on the results of Experiments 1 and 2, the optimal organic matter dissolution effect was achieved when the electromagnetic wave loading sludge condition was set to 260 W power, 45 s loading time, and 20% loading percentage, and the loading internal reflux nitrification liquor condition was set to 400 W power, 75 s loading time, and 10% loading percentage. The principle can be summarized as follows: the addition of electromagnetic waves to synergistically load sludge reflux and nitrification liquor reflux induces high-speed movement of polar molecules inside and outside the microbial cells in the refluxed sludge and nitrification liquor, enhancing the mechanical stress inside and outside the cell walls, promoting cell membrane rupture, and thus releasing intracellular degradable organic matter into the liquid phase. Fluorescence spectroscopy analysis showed a significant increase in the fluorescence intensity of tryptophan-like substances and a significant increase in the SCOD concentration of the supernatant, fully demonstrating that the electromagnetic waves significantly promoted the release of organic matter from the sludge and nitrification liquor. Through the transformation in the anaerobic stage, these substances can rapidly generate volatile organic acids, providing directly usable electron donors for subsequent denitrification.

[0106] Compared with existing technologies, this invention solves the problems of carbon source dependence, high operating costs, and secondary environmental pollution in existing wastewater treatment technologies. Experiments show that electromagnetic wave-assisted loading of sludge recirculation and nitrification liquid recirculation, through microwave action, can cause organic matter from within the sludge cells and nitrification liquid cells to flow out, significantly increasing the concentration of dissolved organic matter in the supernatant and the organic load of the system, providing a green and low-carbon solution for carbon source supply in wastewater treatment plants.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for carbon source supply in wastewater treatment plants based on electromagnetic wave technology, characterized in that, A carbon source supply system for a wastewater treatment plant based on electromagnetic wave technology is adopted. The carbon source supply system for a wastewater treatment plant based on electromagnetic wave technology includes: an A / A / O reactor, which includes an anaerobic tank (1), an anoxic tank (2), and an aerobic tank (3) connected in sequence; an inlet pipe connected to the anaerobic tank (1); a secondary sedimentation tank (4) connected to the aerobic tank (3), the secondary sedimentation tank (4) having a sludge outlet; a first electromagnetic wave loading unit (5), which has a first flow channel, the two ends of the first flow channel being connected to the inlet pipe and the sludge outlet respectively through a sludge return pipe; and a second electromagnetic wave loading unit (6), which has a second flow channel, the two ends of the second flow channel being connected to the anoxic tank (2) and the aerobic tank (3) respectively through a nitrification liquid return pipe; the carbon source supply method for a wastewater treatment plant based on electromagnetic wave technology includes the following steps: 1) The wastewater was treated using an A / A / O reactor and operated stably for a period of time; 2) Part of the sludge obtained from the secondary sedimentation tank is fed into the anaerobic tank as return sludge. The return sludge is continuously excited by electromagnetic waves, which increases the SCOD content of the supernatant of the return sludge output by the first electromagnetic wave loading unit and increases the SCOD content of the subsequent return nitrification liquid. 3) Part of the nitrified liquid from the aerobic tank is fed into the anoxic tank as return nitrified liquid. The return nitrified liquid is continuously excited by electromagnetic waves to increase the SCOD content of the return nitrified liquid output by the second electromagnetic wave loading unit and to increase the SCOD content of the supernatant of the return sludge output by the subsequent first electromagnetic wave loading unit. The dissolved oxygen in the aerobic tank is 1.60-1.70 mg / L; Electromagnetic wave continuous excitation was performed after the A / A / O reactor had been running stably for 25-35 days. The operating temperature is 20-30℃; The sludge return ratio is 65-75%; The nitrification liquor reflux ratio is 280-320%; The sludge retention time is 14-16 days.

2. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: The power of continuous electromagnetic wave excitation for the return sludge is 240-280 W; The duration of continuous electromagnetic wave excitation for the returned sludge is 40-50 s; Returned sludge accounts for 15-25% of the total sludge; The frequency of continuous electromagnetic wave excitation for the return sludge is 2400-2500 MHz.

3. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: The power of continuous electromagnetic wave excitation of the reflux nitrification liquid is 360-440 W; The duration of continuous electromagnetic wave excitation of the reflux nitrification liquid is 70-80 s; The reflux nitrification liquor accounts for 5-15% of the total nitrification liquor; The frequency of continuous electromagnetic wave excitation of the reflux nitrification liquid is 2400-2500 MHz.

4. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: A stirrer is installed inside the anaerobic tank (1).

5. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: A stirrer is installed in the anoxic pool (2).

6. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: An aeration disc is provided in the aerobic tank (3), and the aeration disc is connected to an air pump.

7. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: A peristaltic pump is connected between the first electromagnetic wave loading unit (5) and the water inlet pipe.

8. The carbon source supply method for wastewater treatment plants based on electromagnetic wave technology according to claim 1, characterized in that: A peristaltic pump is provided between the second electromagnetic wave loading unit (6) and the anoxic pool (2).

Images