Household multi-stage sewage treatment equipment and purification process thereof

Abstract

The invention discloses household multi-stage sewage treatment equipment and a purification process thereof. The household multi-stage sewage treatment equipment comprises three septic tanks, the three-grid septic tank is communicated with the biochemical treatment area; the biochemical treatment area comprises a first MBBR (Moving Bed Biofilm Reactor) area, an MBR area and a second MBBR area which are communicated; the fan is communicated with the first MBBR area, the MBR area and the second MBBR area; the MBR area is communicated with an MBR water producing tank; the MBR water producing tank is sequentially communicated with the electrolytic precipitation integrated reaction tank, the ozone catalysis area and the clean water tank, and the MBR water producing tank is also respectively communicated with the ozone catalysis area and the clean water tank. The MBR technology, the MBBR technology, the electrolytic precipitation technology and the ozone catalysis technology are integrated, sewage organic matter removal and nitrogen and phosphorus removal are achieved, three operation modes are switched through the liquid level sensor, and inflow fluctuation is flexibly treated; the whole reactor is smaller in size, good in removal effect, energy-saving and consumption-saving, and suitable for scattered scenes such as rural areas and villas.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a household multi-stage wastewater treatment device and its purification process. Background Technology

[0002] my country's vast rural areas, suburban villas, and numerous scattered residences are characterized by low population density and dispersed living conditions. Constructing centralized sewage collection networks would require enormous investment, present significant construction difficulties, and have low economic viability and feasibility. Therefore, decentralized sewage treatment has become the preferred solution for addressing environmental pollution problems in these areas.

[0003] However, existing decentralized treatment technologies face many challenges: First, water volume fluctuates drastically throughout the day and seasonally, making it difficult for traditional processes to operate stably and efficiently, resulting in high energy consumption; second, there is a lack of professional operation and maintenance personnel, requiring highly intelligent and maintenance-free equipment; third, emission standards are becoming increasingly stringent, especially for nitrogen and phosphorus removal; fourth, space is limited, requiring integrated equipment with a small footprint; and fifth, users expect low operating costs.

[0004] Currently, integrated wastewater treatment equipment developed both domestically and internationally primarily employs A / O and A2 / O processes, operating in a continuous mode. However, this equipment continues to run during periods of low water usage in rural areas, resulting in energy waste. SBR (Sequencing Batch Reactor) technology, on the other hand, is commonly used in large-scale wastewater treatment because it integrates wastewater equalization, biodegradation, nitrification / denitrification, and sedimentation functions, eliminating the need for sludge recirculation and making it suitable for intermittent discharges and situations with significant flow variations. However, SBR technology requires a decanter, and the cost of the control system and equipment contributes to its high price. Therefore, the aforementioned treatment methods cannot fully meet the high-standard, low-cost, and labor-saving needs of decentralized scenarios in rural areas and villas. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-cost, high-performance, worry-free and labor-saving multi-stage household sewage treatment equipment and its purification process.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a household multi-stage sewage treatment device, comprising: a three-compartment septic tank, a biological treatment zone, an integrated electrolytic sedimentation reactor, an ozone catalytic zone, an MBR permeate tank, a blower, and a clear water tank; the three-compartment septic tank and the biological treatment zone are connected; the biological treatment zone includes a first MBBR zone, an MBR zone, and a second MBBR zone connected through an inlet; the blower is connected to the first MBBR zone, the MBR zone, and the second MBBR zone; the MBR zone is connected to the MBR permeate tank; the MBR permeate tank is sequentially connected to the integrated electrolytic sedimentation reactor, the ozone catalytic zone, and the clear water tank, and the MBR permeate tank is also connected to the ozone catalytic zone and the clear water tank respectively.

[0007] Furthermore, the fan is connected to the first MBBR zone, the MBR zone, and the second MBBR zone via a solenoid valve.

[0008] Furthermore, the first MBBR zone is equipped with a liquid level sensor, which is set to three threshold levels: low, medium, and high, corresponding to 30%, 60%, and 90% of the effective water depth of the first MBBR zone, respectively.

[0009] A purification process for a household multi-stage wastewater treatment system includes the following steps:

[0010] S1. Wastewater flows through a three-compartment septic tank for treatment, resulting in supernatant that has undergone preliminary solid-liquid separation and anaerobic treatment.

[0011] S2. The supernatant liquefies and enters the biochemical treatment area, automatically triggering the following three operating modes:

[0012] S2a1. When the water level in the first MBBR zone is below 30% of its height, the blower connected to the first MBBR zone is not ventilated, and the first MBBR zone forms an anoxic environment;

[0013] S2a2: In the first MBBR zone, some organic matter in the supernatant is degraded by facultative anaerobic bacteria, and nitrate reduction is completed by denitrifying bacteria.

[0014] S2a3, the supernatant flows into the MBR zone of the aerobic zone, and after membrane filtration, it enters the MBR zone permeate tank through a suction pump;

[0015] S2b1. When the water level in the first MBBR zone is at a medium level of 30% to 60%, the blower connected to the first MBBR zone is not ventilated, and the first MBBR zone forms an anoxic environment.

[0016] S2b2, the supernatant undergoes partial degradation of organic matter by facultative anaerobic bacteria in the first MBBR zone, and nitrate reduction is completed by denitrifying bacteria;

[0017] S2b3, the supernatant flows into the MBR zone and the second MBBR zone of the aerobic zone;

[0018] In the S2b4 and MBR zones, pollutants are intercepted through membrane filtration. In the second MBBR zone, aerobic bacteria on the surface of the suspended packing material and anaerobic / facultative anaerobic bacteria inside simultaneously degrade organic matter and remove nitrogen before returning it to the MBR zone. Finally, the filtered wastewater enters the permeate tank in the MBR zone.

[0019] S2c1. When the water level in the first MBBR zone is at a high level of 60% to 90%, the blower connected to the first MBBR zone is ventilated, and the first MBBR zone is converted into an aerobic environment; S2c2. The supernatant initially degrades organic matter, ammonia nitrogen, and SS in the first MBBR zone; S2c3. The supernatant flows into the aerobic MBR zone and the second MBBR zone.

[0020] In the S2c4 and MBR zones, pollutants are intercepted through membrane filtration. In the second MBBR zone, aerobic bacteria on the surface of the suspended packing material and anaerobic / facultative anaerobic bacteria inside simultaneously degrade organic matter and remove nitrogen before returning it to the MBR zone. Finally, the filtered wastewater enters the permeate tank in the MBR zone.

[0021] Water from the permeate tank in the S3 MBR zone flows into the clear water tank for storage.

[0022] Furthermore, in step S3, the water in the product water tank within the MBR zone is first subjected to ozone catalysis before flowing into the clear water tank for storage.

[0023] Furthermore, in step S3, the water in the product water tank of the MBR zone first passes through the electrolytic precipitation reaction zone, where electrolysis removes total phosphorus, as well as residual organic matter, ammonia nitrogen, total nitrogen and SS, and then flows into the clear water tank for storage via ozone catalysis.

[0024] Furthermore, the treatment method for the sewage flowing through the three-compartment septic tank in step S1 is as follows:

[0025] S10. After the wastewater flows through the first compartment, it undergoes primary sedimentation and separation for several hours to rapidly settle heavy solids.

[0026] S11, and then flows through the second compartment for deep anaerobic digestion and secondary separation, which takes ≥20 days;

[0027] S12. Finally, the supernatant is obtained by clarification and water buffering in the third compartment, which takes 3 to 6 days.

[0028] Furthermore, the clean water in step S3 can be directly discharged, used for irrigation, or used for flushing toilets.

[0029] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0030] This invention discloses a household multi-stage wastewater treatment device and its purification process, integrating MBR, MBBR, electrolytic precipitation, and ozone catalysis technologies to achieve the removal of organic matter, nitrogen, and phosphorus from wastewater. The wastewater treatment effect is excellent, with removal rates of COD, ammonia nitrogen, total nitrogen, and total phosphorus all exceeding 94%. Three operating modes are switched via a liquid level sensor to flexibly handle large fluctuations in influent flow from 0.3 to 1.5 t / d, ensuring stable treatment performance under various water usage conditions. Furthermore, the device's power equipment consists of only one blower, controlled by a liquid level sensor and solenoid valve, resulting in low failure rate and minimal maintenance, reducing energy consumption by more than 30% compared to traditional equipment. The overall reactor is smaller, has better removal efficiency, higher integration, more flexible control, and lower energy consumption. It is specifically designed for decentralized scenarios such as rural areas and villas, requiring no reliance on municipal pipe networks and is ready to use immediately after installation. Attached Figure Description

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of a household multi-stage sewage treatment device according to an embodiment of the present invention;

[0033] The system includes: 1. Three-compartment septic tank; 2. Biochemical treatment zone; 3. Electrolytic sedimentation integrated reaction tank; 4. Ozone catalysis zone; 5. MBR product water tank; 6. Blower; 7. Clear water tank; 8. Solenoid valve. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0035] This invention provides a household multi-stage sewage treatment equipment and its purification process to solve the problems of high cost, large footprint, poor treatment effect, and troublesome operation and maintenance of sewage treatment methods for decentralized users in rural areas and suburban villas in the prior art.

[0036] For ease of understanding, the specific processes in the embodiments of this application are described below. Please refer to [link / reference]. Figure 1 This application embodiment provides a household multi-stage sewage treatment device, comprising: a three-compartment septic tank 1, a biochemical treatment zone 2, an integrated electrolytic sedimentation reaction tank 3, an ozone catalytic zone 4, an MBR permeate tank 5, a blower 6, and a clear water tank 7.

[0037] The three-compartment septic tank 1 is connected to the biological treatment zone 2; the biological treatment zone 2 includes a first MBBR zone 20, an MBR zone 21 and a second MBBR zone 22 connected through an inlet hole; the blower 6 is connected to the first MBBR zone, the MBR zone and the second MBBR zone, wherein the function of the blower 6 is to provide oxygen to the biological treatment zone 2 and to promote water mixing and flow.

[0038] The blower 6 supplies air to the first MBBR zone 20, MBR zone 21, and second MBBR zone 22 via solenoid valves 8. Control valves controlling the on / off state are also installed in the first MBBR zone 20, MBR zone 21, and second MBBR zone 22. When the blower 6 is not supplying air, all three zones are in an anaerobic environment; when the blower 6 is supplying air, the three zones are in an aerobic environment via the control valves.

[0039] The MBR zone 21 is connected to the MBR permeate tank 5; the MBR permeate tank 5 is sequentially connected to the integrated electrolytic precipitation reactor 3, the ozone catalytic zone 4, and the clear water tank 7, and the MBR permeate tank 5 is also connected to the ozone catalytic zone 4 and the clear water tank 7 respectively. In the wastewater treatment process, the MBR permeate tank 5 mainly serves as a storage and buffer, and to ensure the smooth operation of subsequent processes.

[0040] Furthermore, the first MBBR zone 20 is equipped with a liquid level sensor, which is set to three threshold levels: low, medium, and high, corresponding to 30%, 60%, and 90% of the effective water depth of the first MBBR zone, respectively.

[0041] This invention also discloses a purification process for a household multi-stage wastewater treatment device, comprising the following steps:

[0042] S1. Wastewater flows through a three-compartment septic tank for treatment, resulting in supernatant that has undergone preliminary solid-liquid separation and anaerobic treatment.

[0043] The sewage treatment method in step S1, where it flows through the three-compartment septic tank, is as follows:

[0044] S10. After flowing through the first chamber, the wastewater undergoes primary sedimentation and separation for several hours, rapidly settling heavy solids. Specifically, as wastewater enters the first chamber through the pipe, solids with a specific gravity greater than 1.1 (sand, parasite eggs) accumulate at the bottom, forming a sludge bed; oils / organic matter with a specific gravity less than 0.95 float to the surface. The sludge and scum undergo primary anaerobic reaction under SRT 60d conditions, and the clarified water in the middle layer with SS less than 50mg / L flows by gravity to the second chamber via hydraulic gradient.

[0045] S11, and then flows through the second compartment for deep anaerobic digestion and secondary separation, with a time of ≥20 days; specifically, under an HRT of not less than 20 days, the residual organic matter is converted into CH4 and CO2 by methanogens, and the parasite eggs are inactivated due to the hypoxic environment and biological antagonism; at the same time, the newly generated scum and the settled sludge are separated for the second time, and the sewage enters the third compartment.

[0046] S12. Finally, the supernatant is obtained through clarification, storage, and water buffering in the third compartment, which takes 3-6 days. By this time, the organic matter in the third septic tank has decomposed, and pathogens and parasite eggs have been largely killed. The main function of the third compartment is to temporarily store sediment and the supernatant obtained after the pathogens and parasite eggs have been killed.

[0047] S2. The supernatant liquefies and enters the biochemical treatment area, automatically triggering the following three operating modes.

[0048] The first operating mode is as follows:

[0049] S2a1. When the water level in the first MBBR zone is at a low level, i.e., the water level is not higher than 30%, the blower connected to the first MBBR zone is not ventilated, and the first MBBR zone forms an anoxic environment at this time;

[0050] S2a2: In the first MBBR zone, some organic matter in the supernatant is degraded by facultative anaerobic bacteria, and nitrate reduction is completed by denitrifying bacteria.

[0051] S2a3, the supernatant flows into the MBR zone of the aerobic zone. The supernatant is filtered through the membrane module, and pollutants such as suspended solids and organic matter are trapped outside the membrane. The wastewater is pumped into the MBR permeate tank.

[0052] The second operating mode is as follows:

[0053] S2b1. When the water level in the first MBBR zone is at the middle level, that is, when the water level is between 30% and 60%, the blower connected to the first MBBR zone does not ventilate, and the first MBBR zone forms an anoxic environment.

[0054] S2b2, the supernatant undergoes partial degradation of organic matter by facultative anaerobic bacteria in the first MBBR zone, and nitrate reduction is completed by denitrifying bacteria;

[0055] S2b3, the supernatant flows into the MBR zone and the second MBBR zone of the aerobic zone;

[0056] S2b4. The supernatant is filtered through the membrane module in the MBR zone. Solid suspended matter, organic matter and other pollutants are trapped outside the membrane. The wastewater is pumped into the MBR permeate tank. In the second MBR zone, aerobic bacteria attached to the suspended packing and anaerobic or facultative anaerobic bacteria growing inside further decompose the organic matter in the wastewater into CO2, water and other substances. At the same time, nitrogenous substances in the wastewater are nitrified and denitrified. Finally, the supernatant also enters the permeate tank in the MBR zone.

[0057] The third operating mode is as follows:

[0058] S2c1. When the water level in the first MBBR zone is at a high level, i.e., between 60% and 90%, the blower connected to the first MBBR zone ventilates, causing the first MBBR zone to become an aerobic environment; S2c2. The supernatant undergoes preliminary degradation of organic matter, ammonia nitrogen, and suspended solids (SS) in the first MBBR zone; S2c3. The supernatant flows into the aerobic MBR zone and the second MBBR zone.

[0059] The treatment methods for S2c4, the MBR zone and the second MBBR zone are the same as those for the second operating mode, and the final supernatant also flows into the permeate tank in the MBR zone.

[0060] In step S3, step S2a, S2B, or S2C, the water in the product water tank of the MBR zone flows into the clear water tank for storage, and then the water in the clear water tank is used for direct discharge, irrigation, or toilet flushing.

[0061] Furthermore, in step S3: the water in the product water tank within the MBR zone can be first subjected to ozone catalysis before flowing into the clear water tank for storage.

[0062] Furthermore, in step S5: the water in the product water tank in the MBR zone first passes through the electrolytic precipitation reaction zone, where electrolysis removes total phosphorus, as well as residual organic matter, ammonia nitrogen, total nitrogen and SS, and then flows into the clear water tank for storage via ozone catalysis.

[0063] In this embodiment, the integrated electrolytic precipitation reactor removes total phosphorus, as well as residual organic matter, ammonia nitrogen, total nitrogen, and suspended solids through electrolysis. Simultaneously, free suspended solids are separated in the precipitation tank.

[0064] The treatment indicators for various pollutants after adopting this invention are compared with those of existing technologies, as shown in the table below:

[0065] index This purification process Existing technology COD Biochemical stage: 93% ± 2%; Advanced stage: 23% ± 2%; Cumulative > 99%. Biochemical stage: 80%-88%; Depth stage: 10%-15%; Cumulative 85%-92%. <![CDATA[NH4 + -N]]> Biochemical stage: 96% ± 1%; Advanced stage: <5% cumulative > 96% Biochemical stage: 85%-90% depth stage: ≤3% cumulative 88%-92% TN Biochemical stage: 89% ± 1%; Advanced stage: 8% ± 2%; Cumulative > 94% Biochemical stage: 70%-80%; Depth stage: 5%-8%; Cumulative 75%-85% TP Biochemical stage: 10%; Electrolysis stage: 88% ± 2% (cumulative > 95%) Biochemical stage: 15%-30%; Chemical phosphorus removal: 70%-85%; Cumulative: 80%-90%. SS effluent <3mg / L 5-10 mg / L (MBR process) > 15 mg / L (traditional precipitation)

[0066] As shown in the table above, the processing method of the present invention achieves a removal rate of over 90% for various indicators, demonstrating excellent filtration performance. Compared with existing technologies, it significantly improves the removal efficiency for various indicators, meeting practical application needs.

[0067] This invention discloses a household multi-stage wastewater treatment equipment and its purification process, which integrates MBR, MBBR, electrolytic precipitation and ozone catalysis technologies to achieve the removal of organic matter, nitrogen and phosphorus from wastewater. The wastewater treatment effect is good, and the equipment can switch between three operating modes through a liquid level sensor to flexibly handle large fluctuations in influent volume from 0.3 to 1.5 t / d. It has a high degree of integration and is designed for decentralized scenarios such as rural areas and villas. It does not rely on municipal pipe networks and has good adaptability.

[0068] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A household multi-stage sewage treatment device, characterized in that, include: The system comprises a three-compartment septic tank, a biological treatment zone, an integrated electrolytic sedimentation reactor, an ozone catalytic zone, an MBR permeate tank, a blower, and a clear water tank. The three-compartment septic tank and the biological treatment zone are interconnected. The biological treatment zone includes a first MBBR zone, an MBR zone, and a second MBBR zone, all connected by an inlet. The blower is connected to the first MBBR zone, the MBR zone, and the second MBBR zone. The MBR zone is connected to the MBR permeate tank. The MBR permeate tank is sequentially connected to the integrated electrolytic sedimentation reactor, the ozone catalytic zone, and the clear water tank, and is also connected to the ozone catalytic zone and the clear water tank.

2. The household multi-stage sewage treatment equipment as described in claim 1, characterized in that: The fan is connected to the first MBBR zone, the MBR zone, and the second MBBR zone via a solenoid valve.

3. The household multi-stage sewage treatment equipment as described in claim 1, characterized in that: The first MBBR zone is equipped with a liquid level sensor, which is set to three threshold levels: low, medium, and high, corresponding to 30%, 60%, and 90% of the effective water depth of the first MBBR zone, respectively.

4. A purification process for a household multi-stage wastewater treatment system, characterized in that, The steps include: S1. Wastewater flows through a three-compartment septic tank for treatment, resulting in supernatant that has undergone preliminary solid-liquid separation and anaerobic treatment. S2. The supernatant liquefies and enters the biochemical treatment area, automatically triggering the following three operating modes: S2a1. When the water level in the first MBBR zone is below 30% of its height, the blower connected to the first MBBR zone is not ventilated, and the first MBBR zone forms an anoxic environment; S2a2: In the first MBBR zone, some organic matter in the supernatant is degraded by facultative anaerobic bacteria, and nitrate reduction is completed by denitrifying bacteria. S2a3, the supernatant flows into the MBR zone of the aerobic zone, and after membrane filtration, it enters the MBR zone permeate tank through a suction pump; S2b1. When the water level in the first MBBR zone is at a medium level of 30% to 60%, the blower connected to the first MBBR zone is not ventilated, and the first MBBR zone forms an anoxic environment. S2b2, the supernatant undergoes partial degradation of organic matter by facultative anaerobic bacteria in the first MBBR zone, and nitrate reduction is completed by denitrifying bacteria; S2b3, the supernatant flows into the MBR zone and the second MBBR zone of the aerobic zone; In the S2b4 and MBR zones, pollutants are intercepted through membrane filtration. In the second MBBR zone, aerobic bacteria on the surface of the suspended packing material and anaerobic / facultative anaerobic bacteria inside simultaneously degrade organic matter and remove nitrogen before returning it to the MBR zone. Finally, the filtered wastewater enters the permeate tank in the MBR zone. S2c1. When the water level in the first MBBR zone is at a high level of 60% to 90%, the blower connected to the first MBBR zone is ventilated, and the first MBBR zone is converted into an aerobic environment; S2c2. The supernatant initially degrades organic matter, ammonia nitrogen, and SS in the first MBBR zone; S2c3. The supernatant flows into the aerobic MBR zone and the second MBBR zone. In the S2c4 and MBR zones, pollutants are intercepted through membrane filtration. In the second MBBR zone, aerobic bacteria on the surface of the suspended packing material and anaerobic / facultative anaerobic bacteria inside simultaneously degrade organic matter and remove nitrogen before returning it to the MBR zone. Finally, the filtered wastewater enters the permeate tank in the MBR zone. Water from the permeate tank in the S3 MBR zone flows into the clear water tank for storage.

5. The purification process of the household multi-stage sewage treatment equipment as described in claim 4, characterized in that: In step S3, the water in the product water tank of the MBR zone is first catalyzed by ozone and then flows into the clear water tank for storage.

6. The purification process of the household multi-stage sewage treatment equipment as described in claim 5, characterized in that: In step S3, the water in the product water tank of the MBR zone first passes through the electrolytic precipitation reaction zone, where electrolysis removes total phosphorus, as well as residual organic matter, ammonia nitrogen, total nitrogen and SS, and then flows into the clear water tank for storage via ozone catalysis.

7. The purification process of the household multi-stage sewage treatment equipment as described in claim 4, characterized in that: The sewage treatment method in step S1, where it flows through the three-compartment septic tank, is as follows: S10. After the wastewater flows through the first compartment, it undergoes primary sedimentation and separation for several hours to rapidly settle heavy solids. S11, and then flows through the second compartment for deep anaerobic digestion and secondary separation, which takes ≥20 days; S12. Finally, the supernatant is obtained by clarification and water buffering in the third compartment, which takes 3 to 6 days.

8. The purification process of the household multi-stage sewage treatment equipment as described in claim 4, characterized in that: The clean water in step S3 can be directly discharged, used for irrigation, or used for flushing toilets.

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