Method for synergistically reducing sludge by loading returned sludge and returned nitrification liquid with electromagnetic waves

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to a method for synergistically reducing sludge by loading returned sludge and returned nitrification liquid with electromagnetic waves. The method comprises the following steps: 1) treating sewage by adopting an A / A / O reactor, and stably operating for a period of time; 2) introducing a part of sludge obtained in the secondary sedimentation tank as return sludge into the anaerobic tank, continuously exciting the return sludge by electromagnetic waves, and reducing the accumulated sludge yield in the secondary sedimentation tank; 3, part of the nitrification liquid in the aerobic tank serves as backflow nitrification liquid to be introduced into the anoxic tank, the backflow nitrification liquid is continuously excited by electromagnetic waves, and the accumulated sludge yield in the secondary sedimentation tank is reduced. The backflow sludge and the backflow nitrification liquid are cooperatively loaded through the electromagnetic waves, and the sludge can be remarkably reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to a method for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid. Background Art

[0002] The A / A / O process, a mainstream biological denitrification and phosphorus removal technology, effectively removes organic matter, nitrogen, and phosphorus pollutants from wastewater through an anaerobic-anoxic-aerobic system, making it widely used in municipal wastewater treatment plants. However, the inherent metabolic growth characteristics of the activated sludge process result in the system generating large amounts of excess sludge daily. This sludge, containing pathogens and heavy metals, poses a threat to ecological protection and is also expensive to treat and dispose of.

[0003] Subsequent sludge reduction and process reduction are the two main ways to achieve sludge reduction. Process sludge reduction, also known as in-situ sludge reduction, refers to the process of ensuring that the sewage treatment efficiency remains unchanged during the sewage treatment process, by changing the sewage treatment process or taking certain technical means to minimize the solid biomass discharged to the outside, thereby reducing the yield of residual sludge from the source. Common in-situ sludge reduction technologies include uncoupling technology, hidden growth technology and bioaugmentation technology. However, although in-situ sludge reduction technologies such as uncoupling, hidden growth and bioaugmentation have reduced sludge production to a certain extent, there are still problems such as limited sludge degradation efficiency, high energy consumption, affected system stability and potential environmental risks, which restrict the widespread promotion and engineering application of this technology.

[0004] Electromagnetic wave loading technology, applied to activated sludge processes, has demonstrated significant effectiveness in reducing sludge volume without the need for chemical agents. Its core effects include dissolution and bioremediation. The former uses high-frequency electromagnetic fields to induce the vigorous movement of polar molecules (such as water), disrupting microbial cell walls and promoting the dissolution of intracellular substances. The latter alters cell membrane permeability, interfering with DNA conformation, enzyme activity, and microbial metabolism, ultimately achieving sludge reduction. This technology can significantly influence sludge floc structure, extracellular polymer content, supernatant composition, and dewatering performance under varying operating conditions. Under appropriate energy levels, it can disperse flocs, reduce surface EPS, and improve dewatering. However, excessive radiation can rupture cells, releasing highly viscous macromolecules, increasing sludge viscosity, and impairing dewatering efficiency.

[0005] Therefore, the operating parameters of electromagnetic wave loading sludge can be reasonably adjusted to achieve the sludge reduction effect of the system. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the shortcomings of the above-mentioned existing technologies and provide a method and device for synergistic sludge reduction by loading return sludge and return nitrification liquid with electromagnetic waves. The inventors have discovered that by synergistically loading return sludge and return nitrification liquid with electromagnetic waves, sludge can be significantly reduced.

[0007] The technical solutions provided by the present invention are as follows:

[0008] A system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid comprises: an A / A / O reactor comprising an anaerobic tank, an anoxic tank and an aerobic tank connected in sequence;

[0009] A water inlet pipe connected to the anaerobic tank;

[0010] A secondary sedimentation tank connected to the aerobic tank, wherein the secondary sedimentation tank has a mud outlet;

[0011] A first electromagnetic wave loading unit has a first flow channel, with both ends of the first flow channel connected to the water inlet pipeline and the mud outlet through a sludge return pipe respectively;

[0012] a second electromagnetic wave loading unit having a second flow channel, wherein both ends of the second flow channel are connected to the anoxic tank and the aerobic tank respectively through nitrification liquid return pipes;

[0013] an original return sludge pipe connected to the sludge outlet and the water inlet pipeline;

[0014] and an original reflux nitrification liquid pipe connecting the aerobic tank and the anoxic tank.

[0015] Based on the above technical solution:

[0016] The first electromagnetic wave loading unit continuously excites the returned sludge with electromagnetic waves, thereby reducing the amount of sludge generated by the system;

[0017] The second electromagnetic wave loading unit can continuously excite the refluxed nitrification liquid with electromagnetic waves, thereby reducing the amount of sludge generated by the system;

[0018] The two work together to further improve the sludge reduction effect.

[0019] Furthermore: an agitator is provided in the anaerobic tank.

[0020] Furthermore: a stirrer is provided in the anoxic tank.

[0021] Furthermore: an aeration plate is provided in the aerobic tank, and the aeration plate is connected to an air pump.

[0022] Furthermore: a peristaltic pump is provided between the first electromagnetic wave loading unit and the water inlet pipeline.

[0023] Furthermore: a peristaltic pump is provided in communication between the second electromagnetic wave loading unit and the anoxic tank.

[0024] The present invention also provides a method for synergistically reducing sludge by using electromagnetic waves to load return sludge and return nitrification liquid. The system for synergistically reducing sludge by using electromagnetic waves to load return sludge and return nitrification liquid comprises the following steps:

[0025] 1) Use A / A / O reactor to treat sewage and operate stably for a period of time;

[0026] 2) A portion of the sludge obtained from the secondary sedimentation tank is passed as return sludge into the anaerobic tank, where the return sludge is continuously excited by electromagnetic waves and reduces the cumulative sludge production in the secondary sedimentation tank. Optionally, the sludge that has not been excited by electromagnetic waves is directly passed into the anaerobic tank;

[0027] 3) Part of the nitrification liquid from the aerobic tank is introduced into the anoxic tank as return nitrification liquid, the return nitrification liquid is continuously excited by electromagnetic waves, and the cumulative sludge production in the secondary sedimentation tank is reduced. Optionally, the nitrification liquid that has not been excited by electromagnetic wave technology is directly introduced into the anoxic tank.

[0028] Based on the above technical solution:

[0029] Continuous electromagnetic wave excitation of the returned sludge can reduce the amount of sludge produced by the system, for example, by up to 25-35%;

[0030] Continuous electromagnetic wave excitation of the refluxed nitrification liquid can reduce the amount of sludge produced by the system, for example, by up to 36-40%;

[0031] The two work together to further improve the sludge reduction effect.

[0032] In the above technical solution, steps 2) to 3) can be repeated until all sewage is treated.

[0033] Specifically:

[0034] The power of continuous electromagnetic wave excitation for the return sludge is 230-270 W, preferably 260 W;

[0035] The time for continuous excitation of the electromagnetic wave on the return sludge is 42-48 s, preferably 45 s;

[0036] Return sludge accounts for 15-25% of the total sludge, preferably 20%;

[0037] The frequency of the continuous excitation of the electromagnetic wave for the return sludge is 2400-2500 MHz, preferably 2450 MHz.

[0038] Specifically:

[0039] The power of the electromagnetic wave continuous excitation of the reflux nitration liquid is 340-420 W, preferably 400 W;

[0040] The time for continuous electromagnetic wave excitation of the reflux nitrification liquid is 70-78 s, preferably 75 s;

[0041] The reflux nitrification liquid accounts for 5-15% of the total nitrification liquid, preferably 10%;

[0042] The frequency of the electromagnetic wave continuous excitation of the reflux nitration liquid is 2400-2500 MHz, preferably 2450 MHz.

[0043] Specifically:

[0044] After the A / A / O reactor has been running stably for 25-35 days, preferably 30 days, continuous electromagnetic wave excitation is performed;

[0045] The working temperature is 20-30°C, preferably 25°C;

[0046] The dissolved oxygen in the aerobic tank is 1.62-1.72 mg / L, preferably 1.66 mg / L;

[0047] The sludge return ratio is 65-75%, preferably 70%;

[0048] The nitration liquid reflux ratio is 270-310%, preferably 300%;

[0049] The sludge retention time is 13-15 days, preferably 15 days.

[0050] Specifically, the retention time of the anaerobic tank is 1.8-2.2 h.

[0051] Specifically, the residence time of the anoxic tank is 2.8-3.2 h.

[0052] Specifically, the residence time of the aerobic tank is 5.6-6.0 h.

[0053] The beneficial effects of the present invention are:

[0054] 1. This invention uses electromagnetic waves to simultaneously load the return sludge and internally recirculate nitrification solution to operate the A / A / O reactor, effectively enhancing the biological activity in the sludge. The introduction of electromagnetic waves accelerates protein synthesis and enhances the hydrophobicity of the activated sludge, thereby reducing sludge production. To a certain extent, the radiant energy of the electromagnetic waves enhances the system's energy generation and electron transfer efficiency, thereby accelerating sludge hydrolysis and increasing the degradation rate of organic matter, ultimately significantly improving sludge reduction.

[0055] 2. The present invention can significantly promote the growth of specific functional bacterial communities, making the microbial communities related to sludge reduction in the system more competitive, thereby improving the shock resistance and long-term stability of the system and reducing the risk of decreased treatment effects due to operational fluctuations.

[0056] 3. The technology adopted in the present invention does not rely on the addition of chemical agents. It directly achieves sludge reduction through the efficient treatment of return sludge and internal return nitrification liquid, avoiding the secondary pollution problem that may be caused by chemical residues, ensuring the green and environmentally friendly characteristics of the sewage treatment process, and at the same time reducing the cost of purchasing and using chemicals.

[0057] In summary, the present invention effectively solves a number of technical problems such as low sludge degradation efficiency, high operating energy consumption, and poor system adaptability by simultaneously loading return sludge and internal return nitrification liquid with electromagnetic waves, providing an effective technical solution for sludge reduction in sewage treatment plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a schematic diagram of the system structure for coordinated sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid provided by the present invention.

[0059] Figure 2 This is the relative abundance data of Dechloromonas under different working conditions.

[0060] Figure 3 This is the relative abundance data of the predatory bacteria norank_f__Haliangiaceae under different working conditions.

[0061] Attachment Figure 1 The components represented by the reference numbers are as follows:

[0062] 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; 7. Original return sludge pipe; 8. Original return nitrification liquid pipe. DETAILED DESCRIPTION

[0063] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0064] Unless otherwise specified, the test methods in the examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0065] The sewage water quality indicators are: COD: 240~250mg / L, TN: 35~40mg / L, TP: 3.5~4mg / L, pH: 6~8.

[0066] During the reactor startup phase, the return sludge from the Wuhan Longwangzui Wastewater Treatment Plant was used as inoculated sludge.

[0067] In a specific embodiment, Figure 1 As shown, the carbon source supply system for a sewage treatment plant based on electromagnetic wave technology includes: an A / A / O reactor, a water inlet 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.

[0068] The water inlet pipe is connected to the anaerobic tank 1. The secondary sedimentation tank 4 is connected to the aerobic tank 3, and the secondary sedimentation tank 4 has a sludge outlet. The first electromagnetic wave loading unit 5 has a first flow channel, and the two ends of the first flow channel are connected to the water inlet pipe and the sludge outlet respectively through the sludge return pipe. The second electromagnetic wave loading unit 6 has a second flow channel, and the two ends of the second flow channel are connected to the anoxic tank 2 and the aerobic tank 3 respectively through the nitrification liquid return pipe. The original return sludge pipe 7 is also connected between the sludge outlet and the water inlet pipe. The aerobic tank 3 and the anoxic tank 2 are also connected by the original return nitrification liquid pipe 8.

[0069] The first electromagnetic wave loading unit 5 and the second electromagnetic wave loading unit 6 can respectively adopt the following existing technologies: a box-type electromagnetic wave generator is used, a flow channel is set through the box, and the flow channel material is a silicone tube. The through connection between the flow channel and the electromagnetic wave generator is sealed.

[0070] In order to further evenly mix, an agitator is provided in the anaerobic tank 1 and an agitator is provided in the anoxic tank 2.

[0071] In order to further allow the return sludge and return nitrification liquid to flow at an appropriate speed, a peristaltic pump is provided between the first electromagnetic wave loading unit 5 and the water inlet pipeline, and a peristaltic pump is provided between the second electromagnetic wave loading unit 6 and the anoxic tank 2.

[0072] In a specific embodiment, the method of electromagnetic wave loading return sludge and return nitrification liquid for synergistic sludge reduction can be implemented and verified according to the following steps:

[0073] Step 1: Setting up a system for electromagnetic wave loading of return sludge and return nitrification liquid to coordinate sludge reduction;

[0074] Step 2: By regulating the electromagnetic wave loading conditions (loading power, loading time) and adjusting the amount of returned sludge loaded, a comparative test is conducted to detect the sludge yield in the secondary sedimentation tank before and after the electromagnetic wave loading of the returned sludge;

[0075] Step 3: Based on the operating parameters obtained by optimizing the sludge reduction effect in step 2, the electromagnetic wave loading conditions (loading power, loading time) are adjusted, the loaded internal recirculation nitrification liquid is adjusted, and the sludge production of the secondary sedimentation tank before and after the electromagnetic wave loading of the recirculation sludge is further detected.

[0076] Specifically, the step 1 includes: using organic glass material to ensure the sealing of the three reactors of anaerobic, anoxic and aerobic parts; installing a water inlet pump, an outlet pipe and a regulating valve to ensure controllable flow; installing a stirring device in the anaerobic and anoxic areas to ensure uniform mixing; determining the aeration system setting of the aerobic area and adjusting the gas flow; and setting the loading frequency of the electromagnetic wave loading device.

[0077] Specifically, step 2 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, the sludge inlet and outlet pipes of the continuous flow 2450MHz electromagnetic wave loading device are connected, and a sampling port is left, and a peristaltic pump is added to the sludge inlet pipeline, and the flow rate is adjusted by adjusting the speed of the peristaltic pump.

[0078] During the experiment, the electromagnetic wave loading power was varied by adjusting the input voltage, and the loading percentage was altered by adjusting the peristaltic pump speed. The amount of residual sludge in the secondary sedimentation tank was measured for each operating condition, and the apparent sludge yield was calculated. The operating condition combination with the lowest apparent sludge yield was selected. Microbial gene sequencing was also performed on sludge samples from each stage of the A / A / O process, both when the system was not loaded with electromagnetic waves and when operating under optimal conditions.

[0079] Specifically, step three includes: based on the optimal electromagnetic wave loading sludge operating condition for sludge reduction obtained in step two, adding a continuous flow 2450MHz electromagnetic wave loading circuit to the reactor's nitrification liquid return line to load the internal nitrification liquid, and conducting an electromagnetic wave loading A / A / O internal nitrification liquid return system operation test. During the test, by adjusting the input voltage and peristaltic pump speed, the amount of residual sludge in the system's secondary sedimentation tank was detected under each operating condition. At the optimal sludge reduction, the microbial gene sequences of anaerobic tank sludge, anoxic tank sludge, aerobic tank sludge, and sludge samples before and after loading were tested. The results were compared with the biological characteristics test results of a traditional A / A / O system to verify the impact of the biological effect of electromagnetic waves on the system's sludge yield.

[0080] Example

[0081] 1. The water treatment capacity of the A / A / O system is 1.12 L / h. The effective volume of the main reaction zone is 10.9 L, of which the effective volumes of the anaerobic tank, anoxic tank, and aerobic tank are 2.2 L, 2.2 L, and 6.5 L, respectively, and the hydraulic retention times are 2, 3, and 5.8 h, respectively; the effective volume of the secondary sedimentation tank is 7.0 L.

[0082] 2. The anaerobic and anoxic tanks are equipped with electric stirrers, and the aerobic tanks are equipped with aeration discs at the bottom. The aeration rate is adjusted by a rotor flowmeter. The anaerobic, anoxic, aerobic, and sedimentation tanks are connected by PVC pipes, and the flow of the sludge mixture is controlled by gravity.

[0083] 3. The test temperature was controlled at around 25°C, the DO concentration in the aerobic tank was controlled at 1.66 mg / L, the sludge return ratio was set to 70%, the nitrification solution return ratio was set to 300%, and the sludge retention time was set to 15 days.

[0084] 4. After the system has been running stably for 30 days, electromagnetic waves are used to load the return sludge and return nitrification liquid.

[0085] The A / A / O system is operated with different operating parameters to achieve sludge reduction. The specific information is as follows:

[0086] Experiment 1: Under operating conditions K0 (unloaded), W1 (loading power P = 260W, loading time T = 45s, return sludge loading percentage 20%), W2 (P = 350W, T = 60s, loading percentage 10%), and W3 (P = 420W, T = 30s, loading percentage 15%), the amount of residual sludge in the samples was measured, the apparent sludge yield was calculated, and the effect of electromagnetic wave loading on sludge reduction was systematically analyzed. High-throughput sequencing was performed on sludge samples from the A / A / O system without electromagnetic wave loading and the sludge sample with the best sludge reduction performance under the loading conditions to explore the factors affecting sludge reduction in the system from a microbiological perspective.

[0087] Experiment 2: Under the conditions of X1 (loading power P = 350W, loading time T = 65s, nitrification liquid loading percentage L = 20%), X2 (P = 400W, T = 75s, L = 10%), and X3 (P = 450W, T = 55s, L = 15%), the apparent yield of sludge in the samples was calculated, and high-throughput sequencing was performed on the sludge sample with the best sludge reduction effect under the electromagnetic wave loading internal recirculation nitrification liquid working condition.

[0088] The test results of Experiment 1 are as follows: Under different electromagnetic wave loading sludge conditions, the apparent sludge yield is shown in Table 1.

[0089] Table 1 Apparent sludge yield of electromagnetic wave loaded return sludge under different working conditions

[0090]

[0091] The experimental data in Table 1 show that when no electromagnetic wave is loaded, after 30 days of stable operation, the cumulative sludge production of the system is 321.757 g MLSS, and the apparent sludge yield Y obsThe total sludge production under operating conditions W1 was 222.562 g MLSS, with an apparent sludge yield (Yobs) of 0.1526 g MLSS / g COD, corresponding to a sludge reduction rate of 29.29%. Loading conditions W2 and W3 promoted sludge growth and reproduction, with cumulative sludge production reaching 327.035 and 229.894 g MLSS, respectively, and apparent sludge yields (Yobs) of 0.2830 and 0.2640 g MLSS / g COD, respectively. These increases in sludge production were 31.14% and 22.34% compared to the unloaded condition.

[0092] The results of Experiment 2 are as follows: The sludge apparent yields were obtained under the fixed electromagnetic wave loading condition W1 (P = 260W, T = 45s, and return sludge loading percentage of 20%). Table 2 shows the apparent sludge yields under different electromagnetic wave loading conditions for the internal nitrification solution.

[0093] Table 2 Apparent sludge yield of internal reflux nitrification solution loaded with electromagnetic wave under different working conditions

[0094]

[0095] The cumulative sludge production of the system under operating conditions X1 and X3 is 378.904 and 601.799 g MLSS respectively, and the apparent sludge yield Y obs The values ​​of MLSS / g COD were 0.303 and 0.348 g MLSS / g COD respectively, indicating that the growth and reproduction of sludge were promoted under the X1 and X3 working conditions. Under the working condition X2, the cumulative sludge production of the system was 201.575 g MLSS, and the apparent sludge yield Y obs The sludge reduction rate was 0.1350 g MLSS / g COD, corresponding to a sludge reduction rate of 37.30%. The system achieved the best sludge reduction effect, significantly better than X1 and X3.

[0096] The system is not loaded with electromagnetic waves. , the working condition W1 with the best sludge reduction effect among the working conditions of electromagnetic wave loading sludge, and the working condition X2 with the best sludge reduction effect among the working conditions of internal reflow nitrification liquid loading while the electromagnetic wave loading return sludge working condition W1. The distribution results of functional bacteria for sludge reduction are shown in Table 3.

[0097] Table 3 Distribution of functional bacteria for sludge reduction

[0098]

[0099] For activated sludge systems, the bacterial genera that play an important role in the sludge reduction process mainly include: slow-growing bacteria, hydrolytic bacteria, fermentative bacteria, and predatory bacteria. The slow-growing bacteria associated with sludge reduction in the system mainly include Dechloromonas, Trichococcus, and Azospira. Dechloromonas has the characteristic of stronger catabolism than anabolism. This genus is enriched in the loaded system, and its proportion in the anoxic and aerobic tanks increases more significantly, occupying a higher relative abundance. The hydrolysis of organic matter is considered the main cause of sludge reduction, and the enrichment of fermentative bacteria in the system plays an important role in sludge reduction. In the A / A / O system without electromagnetic wave loading, the total relative abundances of fermentative bacteria were 2.32% An, 2.00% A, and 1.9% O. When electromagnetic wave loading was applied to the sludge (loading power P = 260 W, loading time T = 45 seconds, and return sludge loading percentage of 20%), the total relative abundances of fermentative bacteria in the A / A / O system were 5.35% An, 4.14% A, and 4.03% O. When electromagnetic wave loading was applied to the sludge with internal nitrification solution loading power of 400 W, T = 75 seconds, and L = 10%, the total relative abundances of fermentative bacteria in the A / A / O system were 4.48% An, 2.37% A, and 2.63% O. This indicates that the use of electromagnetic wave loading for sludge and internal nitrification solution enables more efficient hydrolysis in the A / A / O system, generating more organic substrate for the growth of fermentative bacteria. The relative abundance data of Dechloromonas under different working conditions are shown in the figure below. Figure 2 shown.

[0100] The predatory bacteria identified in the system were norank_f__Haliangiaceae. The enrichment of predatory bacteria can promote the lytic-stealth growth process. When the system was not subjected to electromagnetic wave loading, the total relative abundances of predatory bacteria in the A / A / O system were 0.87%, 0.68%, and 0.80%, respectively. Under the operating conditions (loading power P = 260 W, loading time T = 45 s, and return sludge loading percentage of 20%) with sludge loading, and under the operating condition X2 (P = 400 W, T = 75 s, L = 10%) with internal recirculation nitrification solution, the metabolic activity of the microorganisms in the A / A / O system was enhanced, which also led to increases in the relative abundances of predatory bacteria: An: 3.70%, A: 4.52%, and O: 4.87%, respectively. These increases were approximately 4.25-fold, 6.65-fold, and 8.70-fold compared to the bacterial abundances before electromagnetic wave loading. The relative abundance data of predatory bacteria norank_f__Haliangiaceae under different working conditions are shown in the figure below. Figure 3 shown.

[0101] Based on the results of Experiments 1 and 2, optimal sludge reduction was achieved when electromagnetic wave loading was set at 260W power, 45s loading time, and 20% loading percentage for sludge, and 400W power, 75s loading time, and 10% loading percentage for internal nitrification solution loading. The underlying mechanism is that the addition of electromagnetic waves to the sludge and nitrification solution synergistically increases the production of functional proteins, thereby promoting energy generation and electron transfer in the system, facilitating energy metabolism in activated sludge cells, accelerating sludge hydrolysis, and reducing sludge yield. Furthermore, the synergistic loading of electromagnetic waves reduces the production of functional proteins that favor the growth of highly proliferative bacteria (such as fast-growing heterotrophs and nitrifying bacteria), while slow-growing bacteria (such as certain autotrophs and stress-resistant bacteria) become dominant. Consequently, optimal sludge reduction was achieved under the X2 operating condition. Secondly, the introduction of electromagnetic waves enhanced the transport and metabolism capacity of amino acids in activated sludge, increased the synthesis rate of protein, improved the hydrophobicity of activated sludge to a certain extent and reduced sludge production, playing the advantage of sludge reduction in the above experiments.

[0102] Compared with existing technologies, this invention addresses limitations of existing sludge treatment technologies, such as low sludge degradation rates, high energy consumption, and insufficient system impact resistance. Experiments have shown that the optimized operating conditions significantly reduce sludge production by accelerating protein synthesis, disrupting sludge cell metabolism, and enriching functional bacterial communities. It also achieves synergistic optimization of electromagnetic wave loading energy consumption and sludge degradation efficiency, providing a new, green, and low-carbon path for efficient sludge degradation.

[0103] 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 in the scope of protection of the present invention.

Claims

1. A system for synergistic sludge reduction using electromagnetic wave loading of return sludge and return nitrification liquid, characterized in that: include: An A / A / O reactor comprises an anaerobic tank (1), an anoxic tank (2) and an aerobic tank (3) which are connected in sequence; A water inlet pipe connected to the anaerobic tank (1); A secondary sedimentation tank (4) connected to the aerobic tank (3), wherein the secondary sedimentation tank (4) has a mud outlet; A first electromagnetic wave loading unit (5) having a first flow channel, wherein both ends of the first flow channel are connected to the water inlet pipeline and the mud outlet via a mud return pipe; A second electromagnetic wave loading unit (6) having a second flow channel, wherein both ends of the second flow channel are connected to the anoxic tank (2) and the aerobic tank (3) via nitrification liquid return pipes; An original return sludge pipe (7) communicating with the sludge outlet and the water inlet pipeline; and an original reflux nitrification liquid pipe (8) connecting the aerobic tank (3) and the anoxic tank (2).

2. The system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 1 is characterized in that: A stirrer is provided in the anaerobic tank (1).

3. The system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 1 is characterized in that: A stirrer is provided in the anoxic tank (2).

4. The system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 1 is characterized in that: An aeration plate is provided in the aerobic tank (3), and the aeration plate is connected to an air pump.

5. The system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 1 is characterized in that: A peristaltic pump is provided in communication between the first electromagnetic wave loading unit (5) and the water inlet pipeline.

6. The system for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 1, characterized in that: A peristaltic pump is provided in communication between the second electromagnetic wave loading unit (6) and the anoxic pool (2).

7. A method for synergistically reducing sludge by electromagnetic wave loading of return sludge and return nitrification liquid, using the system for synergistically reducing sludge by electromagnetic wave loading of return sludge and return nitrification liquid according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Use A / A / O reactor to treat sewage and operate stably for a period of time; 2) a portion of the sludge obtained from the secondary sedimentation tank (4) is introduced into the anaerobic tank (1) as return sludge, wherein the return sludge is continuously excited by electromagnetic waves and the cumulative sludge production in the secondary sedimentation tank (4) is reduced; 3) A portion of the nitrification liquid from the aerobic tank (3) is introduced into the anoxic tank (2) as a return nitrification liquid, wherein the return nitrification liquid is continuously excited by electromagnetic waves and reduces the cumulative sludge production in the secondary sedimentation tank (4).

8. The method for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 7, characterized in that: The power of continuous electromagnetic wave excitation for return sludge is 230-270 W; The time for continuous excitation of electromagnetic waves on the return sludge is 42-48 s; Return sludge accounts for 15-25% of the total sludge; The frequency of continuous excitation of electromagnetic waves for return sludge is 2400-2500 MHz.

9. The method for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 7, characterized in that: The power of continuous electromagnetic excitation of the reflux nitrification solution is 340-420 W; The time of continuous excitation of electromagnetic waves on the reflux nitrification solution is 70-78 s; The reflux nitrification liquid accounts for 5-15% of the total nitrification liquid; The frequency of the continuous excitation of electromagnetic waves on the reflux nitrification liquid is 2400-2500 MHz.

10. The method for synergistic sludge reduction by electromagnetic wave loading of return sludge and return nitrification liquid according to claim 7, characterized in that: After the A / A / O reactor has been running stably for 25-35 days, continuous electromagnetic wave excitation is performed; Working temperature is 20-30 ℃; The dissolved oxygen in the aerobic tank is 1.62-1.72 mg / L; The sludge return ratio is 65-75%; The reflux ratio of nitrification liquid is 270-310%; The sludge retention time is 13-15 days.

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