A composite process treatment system suitable for rural domestic sewage

Abstract

The present invention discloses a composite process treatment system suitable for rural domestic sewage, including an anaerobic tank, an anoxic tank connected to the bottom of the anaerobic tank, an aerobic multi-media biofilm tank connected to the upper part of the anoxic tank through an inlet system, a sedimentation tank connected to the upper end of the aerobic multi-media biofilm tank through an outlet pipe, a nitrification liquid return pipe and a sludge return pipe respectively connected to the upper and lower ends of the sedimentation tank, wherein the nitrification liquid return pipe and the sludge return pipe are respectively connected to the anoxic tank and the anaerobic tank; and an ecological pond connected to the upper end of the sedimentation tank through an ultraviolet disinfector. The present invention is designed for rural domestic sewage treatment, and the composite process technology is obtained by combining the enhanced biological method with the ecological method to obtain a composite system of a multi-media biofilm treatment system and a high-efficiency ecological pond, which greatly improves the effect of rural domestic sewage treatment.

Description

Technical Field

[0001] The invention relates to the technical field of rural domestic sewage treatment, and in particular to a composite process treatment system suitable for rural domestic sewage. Background Art

[0002] Domestic sewage in most rural areas of my country is discharged directly, and only a few areas are equipped with sewage treatment facilities. However, due to many factors, some areas where sewage treatment facilities are built still have incomplete sewage treatment. At present, the rural population in my country is relatively scattered, the amount of domestic sewage discharged is small, the discharge is scattered, the sewage discharge peaks in the morning, noon and evening, and the water quality and quantity of sewage fluctuate greatly, so a suitable sewage treatment process technology is needed.

[0003] At present, the common domestic sewage treatment process in rural areas is the activated sludge method, but the pure activated sludge method requires high energy consumption and professional technical personnel to regulate, so it is not suitable for rural areas where technical personnel are scarce. Secondly, the ecological treatment process is also widely used, but the pure ecological treatment process generally occupies a large area, has a long hydraulic retention time, and has a low treatment efficiency. Most of the land in rural areas is agricultural land, and the land available for the construction of sewage treatment facilities is limited. Therefore, the pure ecological method is subject to certain restrictions. At present, the biofilm treatment process is also commonly used in rural domestic sewage treatment. The general MBR treatment process has expensive membrane components, which are easy to clog and require backwashing and regular replacement of membrane components. It is not suitable for rural areas with backward economic levels.

[0004] To this end, we propose a composite process treatment system suitable for rural domestic sewage to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a composite process treatment system suitable for rural domestic sewage to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a composite process treatment system suitable for rural domestic sewage, comprising an anaerobic tank, an anoxic tank connected to the bottom of the anaerobic tank, an aerobic multi-media biofilm tank connected to the upper part of the anoxic tank through an inlet system, a sedimentation tank connected to the upper end of the aerobic multi-media biofilm tank through an outlet pipe, a nitrification liquid return pipe and a sludge return pipe respectively connected to the upper and lower ends of the sedimentation tank, wherein the nitrification liquid return pipe and the sludge return pipe are respectively connected to the anoxic tank and the anaerobic tank; and an ecological pond connected to the upper end of the sedimentation tank through an ultraviolet disinfector.

[0007] Preferably, the aerobic multi-media biofilm pool comprises two BAF reaction zones arranged at the lower part of the aerobic multi-media biofilm pool, a limestone matrix layer filled in the BAF reaction zones, a water inlet system and an aeration system sequentially distributed at the bottom of the BAF reaction zones, wherein the water inlet system and the aeration system sequentially increase the water inlet amount and the aeration amount in the two BAF reaction zones; two MBBR reaction zones separated by an isolation baffle arranged at the upper part of the aerobic multi-media biofilm pool, the MBBR reaction zones corresponding to and connected with the BAF reaction zones at the bottom; a first filler and a second filler respectively filled in the two MBBR reaction zones, and a sump arranged in the middle of the top of the aerobic multi-media biofilm pool, the water outlet end of the sump being connected to the outlet pipe.

[0008] Preferably, a detachable dosing system is provided on the water outlet pipe.

[0009] Preferably, two inclined plates inclined toward the middle are arranged at the bottom of the sedimentation tank, the bottom of the inclined plates is connected to a sludge discharge pipe, and one end of the sludge discharge pipe is connected to a sludge return pipe;

[0010] A drainage baffle is hoisted in the middle of the sedimentation tank.

[0011] Preferably, the nitrification liquid reflux pipe and the sludge reflux pipe are provided with a reflux pump and a sludge pump respectively, the nitrification liquid reflux ratio is 300%, and the sludge reflux ratio is 25%.

[0012] Preferably, the ultraviolet sterilizer comprises a sterilizer water inlet pipe and a sterilizer water outlet pipe, the sterilizer water inlet pipe is connected to the sedimentation tank, and the sterilizer water outlet pipe is connected to the ecological pond.

[0013] Preferably, a substrate layer is provided at the bottom of the ecological pond, and submerged plants are mixed and planted on the substrate layer.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention designs a composite process technology for rural domestic sewage treatment, and obtains a composite system of a multi-media biofilm treatment system and a high-efficiency ecological pond by combining the enhanced biological method with the ecological method, which greatly improves the treatment effect of rural domestic sewage, has the advantages of less operating equipment, low energy consumption, and no need for special personnel on duty, long-lasting and stable operation, and the effluent water quality is stable and meets the standards.

[0015] The present invention improves the traditional A 2 O process is strengthened, and the aerobic pool is designed as a multi-media biofilm pool, thus obtaining a new type of rural domestic sewage treatment process based on multi-media biofilm, which can significantly increase the hydraulic load and effectively remove N, P, COD and other pollutants in sewage.

[0016] The core unit of the front-end biological treatment of the present invention is a multi-media biofilm aerobic pool, the bottom layer is provided with air and water distribution devices, and an isolation baffle is provided in the middle, which naturally divides the pool into four reaction zones, thereby increasing the efficiency of microbial biofilm formation. The efficiency of multi-media biofilm in treating domestic sewage is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the present invention;

[0018] Figure 2 It is a schematic diagram of the system framework of the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of the aerobic multi-media biofilm pool in the present invention;

[0020] Figure 4 It is a concentration variation diagram of each pollutant treatment process in the present invention;

[0021] Figure 5 This is a graph showing the change in pollutant removal rate in the present invention.

[0022] In the figure: 1. Anaerobic tank; 11. Anaerobic tank water inlet; 12. Anaerobic tank water outlet; 13. Sludge pump; 14. Sludge return pipe;

[0023] 2. Anoxic tank; 21. Nitration liquid reflux pipe; 22. Reflux pump;

[0024] 3. Aerobic multi-media biofilm pool; 31. First filler; 32. Second filler; 33. Limestone matrix layer; 34. Water collection tank; 35. Water outlet pipe; 36. Water inlet system; 37. Aeration system; 38. Isolation baffle;

[0025] 4. Sedimentation tank; 41. Drainage baffle; 42. Mud discharge pipe; 43. Sedimentation tank water inlet; 44. Inclined plate;

[0026] 5. UV sterilizer; 51. Sterilizer water inlet pipe; 52. Sterilizer water outlet pipe;

[0027] 6. Ecological pond; 61. Submerged plants; 62. Matrix layer; 63. Outlet weir. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described below in conjunction with the accompanying drawings and embodiments.

[0029] See also Figure 1-2The present invention provides a technical solution: a composite process treatment system suitable for rural domestic sewage, comprising an anaerobic tank 1, an anoxic tank 2 connected to the bottom of the anaerobic tank 1, an aerobic multi-media biofilm tank 3 connected to the upper part of the anoxic tank 2 through an inlet system 36, a sedimentation tank 4 connected to the upper end of the aerobic multi-media biofilm tank 3 through an outlet pipe 35, a nitrification liquid return pipe 21 and a sludge return pipe 14 respectively connected to the upper and lower ends of the sedimentation tank 4, wherein: the nitrification liquid return pipe 21 and the sludge return pipe 14 are respectively connected to the anoxic tank 2 and the anaerobic tank 1; and an ecological pond 6 connected to the upper end of the sedimentation tank 4 through an ultraviolet disinfector 5.

[0030] The sewage first enters the anaerobic tank 1 through the anaerobic tank inlet 11, and flows into the anoxic tank 2 by gravity from the anaerobic tank outlet 12. The sewage from the anoxic tank 2 flows into the aerobic multi-media biofilm tank 3 by gravity from the water inlet system 36. The aerobic multi-media biofilm tank 3 purifies the pollutants in the sewage and flows into the sedimentation tank 4 by gravity from the outlet pipe 35, wherein the end of the outlet pipe 35 is connected to the sedimentation tank inlet 43. The sewage in the sedimentation tank 4 flows into the ultraviolet disinfector 5 by gravity through the pipeline, and enters the ecological pond 6 for purification after disinfection and sterilization.

[0031] The present invention is based on high efficiency in sewage treatment, low energy consumption with few operating equipment, compact structure and small footprint, no need for professional technicians to adjust and control, simpler operation and maintenance, and is suitable for rural domestic sewage treatment. The front-end process strengthens the aerobic tank on the basis of the A20 process, adopts a multi-media biofilm aerobic tank as the front end, and an ecological pond is set in the back end. By combining and strengthening the biological method and the ecological method, a composite treatment system suitable for rural domestic sewage treatment is obtained.

[0032] The effluent from the front-end process of the present invention, i.e. the effluent from the UV sterilizer, can stably reach the Class A standard of the Pollutant Discharge Standard for Urban Sewage Treatment Plants (GB18918-2002), and the effluent from the ecological pond is better than the Class A standard. The concentration changes of the main water quality indicators of the inlet and outlet water of the device are shown in the following table:

[0033]

[0034]

[0035] See also Figure 3The bottom layer of the aerobic multi-media biofilm pool 3 is provided with a water inlet system 36 and an aeration system 37. A limestone matrix layer 33 with a particle size of 10 mm directly covers the water inlet system 36 and the aeration system 37. The bottom limestone matrix layer 33 is similar to an aerated biological filter (BAF). The middle partition is incompletely divided into two reaction zones (divided into micro-aeration medium flow reaction zone I and large flow strong aeration reaction zone II). Reaction zone I is a good-cultivation and small-part anaerobic biofilm filter, and reaction zone II is a good-cultivation biofilm filter. The mixed BAF system purifies the sewage and intercepts some suspended matter and some fine particles. The sewage is further purified by two MBBR (mobile biofilm reactor) reaction zones separated by the upper layer. The upper layer is reaction zone III and reaction zone IV. Reaction zone III and reaction zone IV are filled with a first filler 31 and a second filler 32 respectively. The first filler 31 corresponds to the micro-aeration large-particle filler zone, and the second filler corresponds to the strong aeration medium-particle filler zone. An isolation baffle 38 is arranged between reaction zone III and reaction zone IV, and water bodies do not flow between each other. The sewage passes through the MBBR system of the two partitions on the upper layer, and the microorganisms attached to the filler purify the pollutants in the sewage again. The effluent is mixed into one through the middle zigzag water collection tank 34, and flows into the sedimentation tank 4 by gravity through the outlet pipe 35, so that the suspended solids in the sewage are removed.

[0036] The parameters of the aerobic multi-media biofilm pool 3 are designed as follows: the height of the bottom limestone matrix layer 33 is 1 / 3 of the pool body, the filling rate of the mobile fillers in the upper two reaction zones is 50%, an isolation baffle 38 is provided in the middle, and a zigzag overflow water collection tank is provided on the upper layer of the isolation baffle 38, and the mobile fillers have different types and particle sizes. The water flow ratio of reaction zone I, reaction zone III and reaction zone II, reaction zone IV is 2:3, and the aeration ratio is 2:3. The air-water ratio of the aerobic multi-media biofilm pool is 3:1-10:1.

[0037] In one embodiment of the present invention, a detachable dosing system is provided on the outlet pipe 35. The sewage in the aerobic multi-media biofilm pool 3 enters the sedimentation tank 4 through the outlet pipe 35, and the dosing system can be flexibly designed. When the inlet TP concentration is lower than 1 mg / L, the outlet TP reaches the Class A standard, and there is no need to add a dosing system; when the inlet TP concentration is higher than 1 mg / L, a pipeline dosing system can be added according to the actual situation on site. When treating sewage with different inlet concentrations and characteristics, the effluent water quality can meet the standards with the lowest investment and the least operating equipment.

[0038] Two inclined plates 44 inclined toward the middle are arranged at the bottom of the sedimentation tank 4, the bottom of the inclined plates 44 is connected to a sludge discharge pipe 42, and one end of the sludge discharge pipe 42 is connected to a sludge return pipe 14;

[0039] A drainage baffle 41 is installed in the middle of the sedimentation tank 4. In the sedimentation tank 4, most of the sludge is concentrated into the sludge discharge pipe 42 through the inclined plate 44 and discharged outward, and a small part of the sludge entering the sludge discharge pipe 42 enters the anaerobic tank 1 through the sludge return pipe 14. A small part of the sewage above the sedimentation tank 4 flows back to the anoxic tank 2 through the nitrification liquid return pipe 21.

[0040] Furthermore, a reflux pump 22 and a sludge pump 13 are respectively provided on the nitrification liquid reflux pipe 21 and the sludge reflux pipe 14 , and the reflux ratio in the nitrification liquid reflux pipe 21 and the sludge reflux pipe 14 is 1:3.

[0041] The sedimentation tank 4 only needs to return a small amount of sludge into the anaerobic tank 1, and the nitrification liquid is returned to the anoxic tank 2 to improve the removal rate of the N element. The nitrification liquid return ratio is about 300%, and the sludge return ratio is about 25%. The sewage is degraded by microorganisms in the anaerobic tank 1 and the anoxic tank 2 to remove some N, P, COD and other pollutants.

[0042] The ultraviolet disinfector 5 includes a disinfector water inlet pipe 51 and a disinfector water outlet pipe 52. The disinfector water inlet pipe 51 is connected to the sedimentation tank 4, and the disinfector water outlet pipe 52 is connected to the ecological pond 6. The sewage in the sedimentation tank 4 flows into the ultraviolet disinfector 5 by gravity through the pipeline, and enters the ecological pond 6 after disinfection and sterilization. The water quality indicators of the water discharged from the ultraviolet disinfector 5 all meet the first-class A standard for urban sewage discharge. Figure 4 shown.

[0043] In one embodiment of the present invention, a matrix layer 62 is set at the bottom of the ecological pond 6, and submerged plants 61, such as duckweed and hydrilla verticillata, are mixed and planted on the matrix layer 62 to further purify pollutants. Fish and benthic organisms are also put in to improve the ecological chain. The sewage is deeply treated in the ecological pond to further purify pollutants. The effluent from the ecological pond is better than the Class A standard for urban sewage discharge. Specifically, Figure 4-5 Finally, the completely purified sewage is discharged from the outlet weir 63 .

[0044] The treatment system of the present invention can be used in sections. For areas with Class A discharge standards, only the front-end biological method can be used. For areas with stricter discharge standards, a composite process of biological and ecological methods can be used. The process technology has good sewage treatment effect, long-term and stable operation, low energy consumption, no need for special personnel on duty, and the process section can be flexibly designed.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite process treatment system suitable for rural domestic sewage, comprising an anaerobic tank, characterized in that: Also includes: Anoxic tank connected to the bottom of anaerobic tank; an aerobic multi-media biofilm pool connected to the upper part of the anoxic pool through a water inlet system, the aerobic multi-media biofilm pool comprising: two BAF reaction zones arranged at the lower part of the aerobic multi-media biofilm pool; a limestone matrix layer filled in the BAF reaction zone; a water inlet system and an aeration system sequentially distributed at the bottom of the BAF reaction zone, the water inlet system and the aeration system sequentially increasing the water inlet and aeration amounts in the two BAF reaction zones; two MBBR reaction zones separated by an isolation baffle arranged at the upper part of the aerobic multi-media biofilm pool, the MBBR reaction zones corresponding to and connected to the BAF reaction zones at the bottom; a first filler and a second filler respectively filled in the two MBBR reaction zones; and a water collection tank arranged in the middle of the top of the aerobic multi-media biofilm pool, the water outlet end of the water collection tank being connected to a water outlet pipe, and a detachable dosing system being provided on the water outlet pipe of the aerobic multi-media membrane pool; A sedimentation tank connected to the upper end of the aerobic multi-media biofilm tank through an outlet pipe; two inclined plates inclined toward the middle are arranged at the bottom of the sedimentation tank, the bottom of the inclined plates is connected to a sludge discharge pipe, and one end of the sludge discharge pipe is connected to a sludge return pipe; a drainage baffle is hoisted in the middle of the sedimentation tank; The nitrification liquid return pipe and the sludge return pipe arranged at the upper and lower ends of the sedimentation tank are respectively connected, and the nitrification liquid return pipe and the sludge return pipe are respectively connected to the anoxic tank and the anaerobic tank; and an ecological pond connected to the upper end of the sedimentation tank through an ultraviolet sterilizer.

2. A composite process treatment system suitable for rural domestic sewage according to claim 1, characterized in that: The nitrification liquid reflux pipe and the sludge reflux pipe are respectively provided with a reflux pump and a sludge pump, the nitrification liquid reflux ratio is 300%, and the sludge reflux ratio is 25%.

3. A composite process treatment system suitable for rural domestic sewage according to claim 1, characterized in that: The ultraviolet sterilizer comprises a sterilizer water inlet pipe and a sterilizer water outlet pipe, wherein the sterilizer water inlet pipe is connected with the sedimentation tank, and the sterilizer water outlet pipe is connected with the ecological pond.

4. The composite process treatment system for rural domestic sewage according to claim 1 is characterized in that: A substrate layer is arranged at the bottom of the ecological pond, and submerged plants are mixed and planted on the substrate layer.

Images