A decentralized biological-ecological combined treatment device and method for domestic sewage

Abstract

The application provides a kind of distributed domestic sewage biological-ecological combined treatment device and method, it is related to sewage biological, ecological treatment technical field, including biological treatment area and ecological treatment area, the ecological treatment area is located in the right side of biological treatment area, the biological treatment area is divided into two aerobic biological reaction zones by partition baffle, wherein the lower part is lower aerobic biological reaction zone, and the upper part is upper aerobic biological reaction zone. By the addition of modified suspended filler in biological treatment area, the sludge concentration in lower aerobic reaction zone can be increased from 2-4 gMLSS / L to 10-20 gMLSS / L, and activated carbon and Fe3O4 modified suspended filler can also accelerate the electron transfer efficiency in the degradation process, achieving efficient and stable removal of COD, NH4+ ‑ N; the upper aerobic reaction zone adopts immobilized microorganism technology, which can effectively retain aerobic denitrification bacteria and avoid its serious loss, thereby significantly improving the denitrification capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biological and ecological treatment of sewage, in particular to a decentralized domestic sewage biological-ecological combined treatment device and method. BACKGROUND

[0002] Highway service area sewage and rural domestic sewage are characterized by decentralized discharge, which is difficult to be effectively collected and treated. Direct discharge can cause eutrophication of surrounding water bodies, causing the death of aquatic organisms, destroying the ecological balance of water areas, and seriously affecting the ecological environment of service areas or rural areas and the health of service area passers-by or rural residents. Therefore, it is urgent to carry out economic and green management work for decentralized domestic sewage.

[0003] At present, the process for treating decentralized domestic sewage mainly includes buried integrated treatment technology, SBR, MBR, stabilization pond, ecological treatment technology, etc. Among them, the buried integrated technology, SBR and MBR are biological treatment, which has the advantages of anti-impact load performance, efficient removal of nitrogen pollutants, etc., but has the disadvantages of high construction and operation cost, complicated management and maintenance, large sludge production, etc. Operators often shut down the treatment facilities to save expenses, resulting in that the effluent cannot finally meet the discharge requirements. The stabilization pond and artificial wetland are ecological treatment, which has the advantages of energy saving, low cost and easy operation and maintenance, but has the disadvantages of poor removal effect of ammonia nitrogen and total nitrogen, great influence of temperature, non-compliance of effluent, large occupation area, etc. Single wastewater treatment technology has been difficult to meet the more stringent discharge standards. The use of biological-ecological combined treatment can achieve the final discharge standard of decentralized domestic sewage.

[0004] The biological-ecological combined treatment device (structure) is the functional implementation subject of functional microorganisms, plants, artificial (natural) media, etc. for degrading pollutants, and is the core component for completing the low-cost, efficient and standard treatment of domestic sewage. The optimal combination and reasonable configuration of the configuration design and functional space of the biological-ecological combined treatment device are crucial to improve the treatment efficiency of decentralized domestic sewage. The present application optimally combines biological treatment with ecological treatment, introduces modified biological carrier filler and immobilized aerobic denitrifying bacteria balls in the biological treatment unit, realizes full utilization of DO in the whole oxygen environment, and achieves full-scale denitrification of wastewater without creating anaerobic environment; combines the advantages of biological and ecological treatment, realizes the discharge standard of decentralized sewage under the requirements of reducing occupation area, reducing energy consumption and easy operation and maintenance; optimally matches the structure of biological unit and ecological unit to maximize their respective functions; uses gravity flow, water level difference, etc. to realize self-conveying of wastewater, and reduces the number of energy-consuming equipment. The decentralized domestic sewage biological-ecological combined treatment device according to the present application has the advantages of small occupation area, strong temperature and load impact resistance, low construction and maintenance cost, easy operation and maintenance, and standard discharge, and the effluent can be directly reused after disinfection treatment. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a kind of dispersed domestic sewage biological-ecological combined treatment device and method, solve the single dispersed sewage treatment method existence construction operation cost is high, management and maintenance are complicated, sludge production is large, land area is relatively large, low-temperature denitrification efficiency is poor and other problems.

[0006] To achieve the above object, the present application is realized by the following technical scheme: a kind of dispersed domestic sewage biological-ecological combined treatment device, including biological treatment area and ecological treatment area, the ecological treatment area is located in the right side of biological treatment area, the biological treatment area is divided into two aerobic biological reaction zones by partition baffle, wherein the lower one is lower aerobic biological reaction zone, and the upper one is upper aerobic biological reaction zone, the upper aerobic biological reaction zone is composed of baffle and left partition, the lower aerobic biological reaction zone and upper aerobic biological reaction zone are communicated by the channel formed by partition baffle and the left side of biological treatment area inner wall, the inner wall bottom of lower aerobic biological reaction zone is formed by first pad and second pad and has different slope closed slope, the bottom of biological treatment area is respectively provided with water inlet pipe, first air distribution pipe and second air distribution pipe, water distribution guide plate is connected in water inlet pipe;Modified suspended filler and aerobic activated sludge are sequentially arranged in the lower aerobic biological reaction zone, the upper aerobic biological reaction zone is connected with the channel formed between left partition and partition baffle, and the bottom of the upper aerobic biological reaction zone is provided with first water distribution plate, and immobilized aerobic denitrifying bacteria balls are stacked above the first water distribution plate;The upper aerobic biological reaction zone is communicated with ecological treatment area through the channel formed between the right side of biological treatment area and right partition.

[0007] Preferably, the bottom of the ecological treatment area is provided with a second water distribution plate, and the top right side of the ecological treatment area is provided with a water outlet pipe.

[0008] The ratio of the distance and length of the second water distribution plate to the bottom surface of the ecological treatment area is 0.005, and a plurality of circular holes are uniformly formed in the upper side of the first water distribution plate, and the diameter of the holes is 5mm, and the porosity is 0.4-0.5;A plurality of slits are uniformly formed in the upper side of the second water distribution plate, and the length of the slits is 5cm, the width is 2cm, and the porosity is 0.3-0.4.

[0009] Preferably, the second water distribution plate is provided with gravel, coal cinder and soil medium from bottom to top, respectively, a blocking plate is laid on the contact surface between the coal cinder and the soil medium, and emergent plants are planted in the soil medium.

[0010] Preferably, the first and second pads in the lower aerobic bioreactor zone are sealed together on one side and closely adhere to the bottom surface of the inner wall of the lower aerobic bioreactor zone. The other sides of the first and second pads are respectively tightly sealed to the wall of the lower aerobic bioreactor zone. The angle between the first pad and the bottom surface of the lower aerobic bioreactor zone is 10°, and the angle between the second pad and the bottom surface of the lower aerobic bioreactor zone is 20°-30°.

[0011] Preferably, the upper surface of the water distribution guide plate is connected to the left wall of the biological treatment area, and the lower surface is arranged parallel to the first pad plate;

[0012] The first air distribution pipe is placed on the sealing line of the first pad and the second pad, and the second air distribution pipe is placed at the junction of the second pad and the right wall of the biological treatment area. Both the first air distribution pipe and the second air distribution pipe are provided with aeration holes and are arranged in a straight line. The direction of the aeration holes of the first air distribution pipe is parallel to the second pad, and the direction of the aeration holes of the second air distribution pipe is vertically upward.

[0013] Preferably, a channel is formed between the first water distribution plate and the partition baffle; the channel between the partition baffle and the left wall of the biological treatment zone, the channel between the partition baffle and the left partition, the channel between the first water distribution plate and the partition baffle, and the channel between the right wall of the biological treatment zone and the right partition are all the same width as the biological treatment zone and the ecological treatment zone; the biological treatment zone and the ecological treatment zone are the same width, with a length ratio of 1:(2-3) and a height ratio of (2-3):1.

[0014] Preferably, the immobilized aerobic denitrifying bacterial balls are composed of polyvinyl alcohol, sodium alginate, and solid carbon source powder as immobilization materials, which are then encapsulated, separated, screened, and compounded into an aerobic denitrifying composite bacterial agent. The optimal ratio of the immobilization materials is 10.103% polyvinyl alcohol, 1.548% sodium alginate, and 0.732% solid carbon source powder. The immobilized aerobic denitrifying bacterial balls have a diameter of 5-10 mm and a density of 1.09 × 10³ g / cm³. 3 Furthermore, the stacking thickness of the immobilized aerobic denitrifying bacteria balls in the upper aerobic bioreactor zone is 3-5 cm.

[0015] Preferably, the gravel, cinder, and soil media in the ecological treatment area are filled to equal heights;

[0016] The lower aerobic bioreactor zone is filled with supported activated carbon and Fe3O4, with an optimal loading ratio of 2:1. The modified suspended packing material is in the form of discs, 1-3 cm in diameter and 0.5-1 cm thick, with a bulk density of 0.5-2.5 kg / m³ in the lower aerobic bioreactor zone. 3 .

[0017] Preferably, a decentralized domestic sewage biological-ecological combined treatment method comprises the following steps:

[0018] S1. The lower part of the biological treatment zone is an aerobic environment, and the enrichment and adhesion of aerobic microorganisms can be realized by the activated carbon and Fe3O4 modified suspended filler, and the pollutants in the water are filtered, adsorbed and degraded through physical, chemical and microbial processes under the action of the modified suspended filler and the attached aerobic microorganisms, most of the COD in the wastewater is degraded by heterotrophic aerobic microorganisms, and NH4+ - N in the wastewater is converted into NO3- - N by the attached autotrophic nitrifying bacteria, so that the sewage is preliminarily purified.

[0019] S2. After the preliminarily purified sewage enters the upper part of the aerobic reaction zone, it is fully contacted with the fixed bed of the immobilized aerobic denitrifying bacteria, the bed thickness is thin, and the upper part of the aerobic reaction zone is open, so that the natural reoxygenation can be carried out, thereby maintaining a low aerobic environment, and the residual COD in the wastewater and the generated NO3- - N in the lower part of the aerobic reaction zone all enter the interior of the bacteria ball through the pore channel of the immobilized aerobic denitrifying bacteria ball, so as to be fully contacted with the aerobic denitrifying bacteria agent, the aerobic denitrifying bacteria uses the residual COD in the wastewater as a carbon source to reduce N2 to escape, so that the wastewater is secondarily purified.

[0020] S3. After the wastewater is secondarily purified, it further enters the ecological treatment zone, and part of the phosphorus pollutants can be removed under the physical adsorption and chemical precipitation of the gravel, cinder and soil medium; then the wastewater enters the root zone of the emergent plant through the gap of the blocking plate, and under the physical blocking of the blocking plate, the plant's rich root system can only grow horizontally into a "root wall", the thick and dense "root wall" and the rich microbial flora attached thereto can fully absorb the residual nitrogen and phosphorus pollutants in the wastewater as growth nutrients, so that the wastewater is finally purified and finally discharged up to the standard.

[0021] Preferably, the oxygen concentration of the aerobic environment in S1 is greater than 5 mg / L, and the oxygen concentration of the aerobic denitrifying bacteria in the low aerobic environment in S2 is 2-5 mg / L.

[0022] The application provides a decentralized domestic sewage biological-ecological combined treatment device and method.

[0023] The application has the advantages of high impact load capacity and low sludge yield, the modified suspended filler in the biological treatment zone can increase the sludge concentration in the lower part of the aerobic reaction zone from 2-4 gMLSS / L to 10-20 gMLSS / L, and the activated carbon and Fe3O4 modified suspended filler can also accelerate the electron transfer efficiency in the degradation process, so that the COD, NH4+- The high-efficiency stable removal of N; the upper aerobic reaction zone adopts the immobilized microorganism technology, can effectively retain the aerobic denitrification bacteria, avoids the serious loss, and thus significantly improves the denitrification capacity; the activated carbon and Fe3O4 modified suspended filler can improve the performance of the activated sludge and strengthen the sludge reduction, and can reduce the sludge yield by 1 / 2-2 / 3, and realizes the sludge reduction.

[0024] The device has low operation and maintenance cost and small land occupation. The upper aerobic reaction zone is designed to be open and the thin layer of immobilized aerobic denitrification bacteria balls is stacked, so that the natural reoxygenation of wastewater can be realized without secondary aeration, and the aerobic denitrification process can be realized; the immobilized material adopts waste straw powder and waste tea dregs powder, which can be used as the carbon source in the denitrification process, and no additional organic carbon source is needed; the ecological treatment unit fully utilizes the water head difference, and no power pump is needed, and no aeration equipment is needed in the ecological treatment zone, so that the operation and maintenance cost of the combined device is relatively low. Due to the high sludge concentration and high pollutant degradation rate in the biological treatment zone, the pollutant removal amount per unit volume is improved, so that the land occupation of the combined device can be effectively reduced.

[0025] The present application improves the overall pollutant removal efficiency of the reaction zone, and the specific setting of the position and aeration angle of the first gas distribution pipe and the gas distribution pipe, and the slope formed by the combination of the first pad and the second pad can effectively improve the flow state of the water flow in the lower aerobic reaction zone and greatly reduce the "dead zone" caused by the corner accumulation of the filler, and can realize the internal circulation of wastewater in the lower aerobic reaction zone, so as to ensure the full and effective contact between the microorganisms in the filler and the wastewater, and significantly improve the pollutant removal efficiency of the reactor.

[0026] The treated wastewater can achieve full-season discharge standard, the high sludge concentration in the biological treatment zone, the effective retention of aerobic denitrification bacteria, the degradation rate of pollutants in the biological treatment zone can reach more than 98% in full season, and the pollution load of the ecological treatment zone can be effectively reduced; the ecological treatment zone is provided with cold-resistant emergent plants with developed root systems, and the setting of the blocking plate can form a thick and dense "root wall" and a large number of functional microorganisms, so as to fully utilize the absorption and degradation of the root system and the functional microorganisms to the residual nitrogen and phosphorus pollutants, and finally realize the full-season discharge standard of the wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 It is a structural schematic diagram of the device in the present application;

[0028] Fig. 2 It is a real object diagram of the modified suspended filler in the present application;

[0029] Fig. 3 It is a real object diagram of the immobilized aerobic denitrification bacteria ball in the present application.

[0030] The components are as follows: 1. Biological treatment zone; 2. Ecological treatment zone; 3. Inlet pipe; 4. Water distribution guide plate; 5. First pad plate; 6. Second pad plate; 7. First air distribution pipe; 8. Second air distribution pipe; 9. Modified suspended packing material; 10. Zone baffle; 11. Left partition plate; 12. First water distribution plate; 13. Immobilized aerobic denitrifying bacteria balls; 14. Right partition plate; 15. Second water distribution plate; 16. Gravel; 17. Cinder; 18. Barrier plate; 19. Soil medium; 20. Emergent plants; 21. Outlet pipe. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0032] like Figs. 1-3 As shown, this embodiment of the invention provides a decentralized biological-ecological combined treatment device for domestic sewage, including a biological treatment zone 1 and an ecological treatment zone 2. The ecological treatment zone 2 is located to the right of the biological treatment zone 1. The biological treatment zone 1 is divided into two aerobic biological reaction zones by a partition baffle 10, wherein the lower one is the lower aerobic biological reaction zone and the upper one is the upper aerobic biological reaction zone. The upper aerobic biological reaction zone is composed of the baffle 10 and the left partition 11. The lower aerobic biological reaction zone and the upper aerobic biological reaction zone are connected by a channel formed by the partition baffle 10 and the left side of the inner wall of the biological treatment zone 1. The bottom surface of the inner wall of the lower aerobic biological reaction zone is formed by a first pad 5 and a second pad. Plate 6 forms a closed inclined plane with different slopes. The bottom of the biological treatment zone 1 is provided with an inlet pipe 3, a first air distribution pipe 7, and a second air distribution pipe 8. The inlet pipe 3 is connected to a water distribution guide plate 4. Modified suspended packing material 9 and aerobic activated sludge are arranged in sequence in the lower aerobic biological reaction zone. The upper aerobic biological reaction zone is connected to the channel formed between the left partition plate 11 and the partition baffle 10. The bottom of the upper aerobic biological reaction zone is provided with a first water distribution plate 12, and stacked immobilized aerobic denitrifying bacteria balls 13 are arranged above the first water distribution plate 12. The upper aerobic biological reaction zone is connected to the ecological treatment zone 2 through the channel formed between the right side of the biological treatment zone 1 and the right partition plate 14.

[0033] The bottom of the ecological treatment zone 2 is provided with a second water distribution plate 15, and the top right side of the ecological treatment zone 2 is provided with a water outlet pipe 21.

[0034] The ratio of the distance between the second water distribution plate 15 and the bottom surface of the ecological treatment area 2 to the length is 0.005, the first water distribution plate 12 is uniformly provided with a circular hole above the first water distribution plate 12, and the hole diameter is 5 mm, and the porosity is 0.4-0.5; the second water distribution plate 15 is uniformly provided with a gap above the second water distribution plate 15, and the gap length is 5 cm, the gap width is 2 cm, and the porosity is 0.3-0.4;

[0035] The second water distribution plate 15 is provided with gravel 16, cinder 17 and soil medium 19 from bottom to top, respectively, a barrier plate 18 is laid on the contact surface between the cinder 17 and the soil medium 19, and the soil medium 19 is planted with emergent plants 20;

[0036] The first pad 5 and the second pad 6 in the lower aerobic biological reaction area are single-sided butt joint and sealed, and are tightly attached to the inner wall bottom surface of the lower aerobic biological reaction area, the other sides of the first pad 5 and the second pad 6 are respectively tightly sealed with the wall body of the lower aerobic biological reaction area, the first pad 5 forms an angle of 10° with the bottom surface of the lower aerobic biological reaction area, and the second pad 6 forms an angle of 20°-30° with the bottom surface of the lower aerobic biological reaction area;

[0037] The upper plate surface of the water distribution guide plate 4 is connected with the left wall body of the biological treatment area 1, and the lower plate surface is parallelly arranged with the first pad 5;

[0038] The first air distribution pipe 7 is arranged on the sealing line of the first pad 5 and the second pad 6, the second air distribution pipe 8 is arranged at the abutting position of the second pad 6 and the right wall body of the biological treatment area 1, the first air distribution pipe 7 and the second air distribution pipe 8 are both provided with aeration holes and are arranged in a straight line, the aeration hole direction of the first air distribution pipe 7 is parallel to the second pad 6, and the aeration hole direction of the second air distribution pipe 8 is vertically upward;

[0039] The first water distribution plate 12 and the partition baffle 10 form a channel; the channel between the partition baffle 10 and the left wall body of the biological treatment area 1, the channel between the partition baffle 10 and the left partition plate 11, the channel between the first water distribution plate 12 and the partition baffle 10, and the channel between the right wall body of the biological treatment area 1 and the right partition plate 14 are all equal in width to the biological treatment area 1 and the ecological treatment area 2; the biological treatment area 1 and the ecological treatment area 2 are equal in width, the length ratio is 1:2-3, and the height ratio is 2-3:1;

[0040] The immobilized aerobic denitrification bacteria ball 13 is made of polyvinyl alcohol, sodium alginate and solid carbon source powder (waste straw powder, waste tea dregs, etc.) as immobilized materials to embed, separate, select and compound aerobic denitrification composite microbial agent, the best ratio of the immobilized materials is polyvinyl alcohol 10.103%, sodium alginate 1.548% and solid carbon source powder 0.732%, the immobilized aerobic denitrification bacteria ball 13 has a diameter of 5-10 mm and a density of 1.09×103 g / cm 3 , and the stacking thickness of the immobilized aerobic denitrification bacteria ball 13 in the upper aerobic biological reaction area is 3-5 cm;

[0041] The filling height of the gravel 16, the cinder 17 and the soil medium 19 in the ecological treatment zone 2 is equal;

[0042] The lower aerobic biological reaction zone is filled with activated carbon and Fe3O4, and the optimal loading ratio of the activated carbon and Fe3O4 is 2:1, the modified suspended filler 9 is in the shape of a round sheet with a diameter of 1-3 cm and a thickness of 0.5-1 cm, and the packing density of the modified suspended filler 9 in the lower aerobic biological reaction zone is 0.5-2.5 kg / m 3 ;

[0043] The width of the water distribution guide plate 4 is 2D, the length of the upper plate surface and the lower plate surface is 1 / 2D and 3DD respectively, DD is the diameter of the water inlet pipe 3, the ratio of the distance between the partition baffle 10 and the left wall, the distance between the partition baffle 10 and the left partition plate 11, the distance between the first water distribution plate 12 and the partition baffle 10, the distance between the right wall and the right partition plate 14 and the length of the biological treatment zone 1 is 0.03, 0.01, 0.01 and 0.01 respectively, the top of the left wall, the top of the left partition plate 11 and the top of the right partition plate 14 are at the same height, the top of the partition baffle 10 and the top of the right wall are at the same height, and the top of the left wall is 10 cm higher than the top of the right wall;

[0044] The wastewater enters the biological treatment zone 2 through the water inlet pipe 3, and flows downward along the slope formed by the first mat 5 under the guide action of the water distribution guide plate 4, and flows upward along the slope formed by the second mat 6 together with the modified suspended filler 9 under the driving of aeration at the first air distribution pipe 7, and changes the movement track under the driving of aeration at the second air distribution pipe 8, and flows upward together with the modified suspended filler 9, so as to form the internal circulation in the lower biological reaction zone, the pollutants in the wastewater fully contact with the microorganisms attached to the modified suspended filler 9, and the COD, NH4+ - N and other pollutants in the wastewater are preliminarily purified;

[0045] After the preliminary purification, the wastewater enters the channel between the left wall of the biological treatment zone 2 and the partition baffle 10, and then changes the direction through the channel formed by the partition baffle 10 and the left partition plate 11, and then enters the upper biological zone, and fully contacts with the stacked immobilized aerobic denitrifying bacteria balls 13 after uniform water distribution by the first water distribution plate 12, and the generated NO3- - N and the residual COD in the wastewater are further degraded under the action of the aerobic denitrifying bacteria agent, and the wastewater is preliminarily purified in the upper aerobic reaction zone;

[0046] The wastewater after the intermediate purification is dropped to the ecological treatment area 2 through the passage between the right wall of the biological treatment area 1 and the right partition plate 14, and after being uniformly distributed by the water distribution plate II 15, the wastewater passes through the gravel layer 16 and the cinder layer 17, respectively, and the remaining organic matter, nitrogen and phosphorus in the wastewater are further removed by the filler and the microorganisms attached thereto through adsorption, precipitation, absorption and transformation; then the wastewater enters the thick and dense root wall through the group partition plate 18, and the soil medium 19, developed root system and rich microorganisms further absorb and transfer the nitrogen and phosphorus nutrients, and the wastewater is finally purified and discharged through the outlet pipe 21.

[0047] A distributed domestic sewage biological-ecological combined treatment method, comprising the following steps:

[0048] S1. The lower aerobic reaction area of the biological treatment area 1 is a sufficient aerobic environment, and the enrichment and attachment of aerobic microorganisms can be achieved through the activated carbon and Fe3O4 modified suspended filler 9. Through the physical, chemical and microbial processes of the modified suspended filler 9 and the attached aerobic microorganisms, the pollutants in the water are filtered, adsorbed and degraded. Most of the COD in the wastewater is degraded by heterotrophic aerobic microorganisms, and NH4+ - N in the wastewater is converted to NO3- - N by the autotrophic nitrifying bacteria group attached to the modified suspended filler 9, so as to realize the preliminary purification of the wastewater;

[0049] S2. After the wastewater after the preliminary purification enters the upper aerobic reaction area, it is in full contact with the fixed aerobic denitrifying bacteria ball 13 bed. Because the bed thickness is thin, and the upper aerobic reaction area is open, it can be naturally reoxygenated, so as to maintain a low aerobic environment. The remaining COD in the wastewater and NO3- - N generated in the lower aerobic reaction area all enter the inside of the fixed aerobic denitrifying bacteria ball 13 through the pore channel, so as to be in full contact with the aerobic denitrifying bacteria agent. The aerobic denitrifying bacteria use the remaining COD in the wastewater as a carbon source to reduce N2 to escape in a low aerobic environment, so as to realize the intermediate carbon removal and nitrogen removal purification of the wastewater;

[0050] S3. The wastewater after the medium-level purification further enters the ecological treatment area 2, under the physical adsorption and chemical precipitation of the gravel 16, the coal cinder 17 and the soil medium 19, part of the phosphorus pollutants can be removed; then the wastewater enters the root zone of the emergent plant 20 through the gap of the blocking plate 18, under the physical blocking of the blocking plate 18, the abundant root system of the plant can only grow horizontally into a “root wall”, the thick and dense “root wall” and the abundant microbial flora attached thereto can fully absorb the residual nitrogen and phosphorus pollutants in the wastewater as the nutrient substances in the growth process, so that the ultimate purification of the wastewater is realized and the final discharge is up to the standard; the oxygen concentration in the aerobic environment in S1 is >5mg / L; the oxygen concentration in the low-oxygen environment for the aerobic denitrifying bacteria in S2 is 2-5mg / L.

[0051] While the embodiments of the application have been shown and described, it is to be understood that the embodiments proposed are only by way of example and are not to be taken as limiting the scope of the application. The scope of the application is to be limited solely by the claims that follow and the equivalents thereof.

Claims

1. A decentralized biological-ecological combined treatment device for domestic sewage, comprising a biological treatment zone (1) and an ecological treatment zone (2), characterized in that: The ecological treatment zone (2) is located at the right side of the biological treatment zone (1), the biological treatment zone (1) is divided into two aerobic biological reaction zones by the partition baffle (10), the lower one is the lower aerobic biological reaction zone, and the upper one is the upper aerobic biological reaction zone, the upper aerobic biological reaction zone is composed of the baffle (10) and the left partition baffle (11), the lower aerobic biological reaction zone and the upper aerobic biological reaction zone are communicated by the channel formed by the partition baffle (10) and the left wall of the biological treatment zone (1), the inner wall bottom surface of the lower aerobic biological reaction zone is formed into closed inclined planes with different slopes by the first pad (5) and the second pad (6), the bottom of the biological treatment zone (1) is respectively provided with the water inlet pipe (3), the first air distribution pipe (7) and the second air distribution pipe (8), the water inlet pipe (3) is connected with the water distribution flow guide plate (4) inside, the modified suspended filler (9) and the aerobic activated sludge are sequentially arranged in the lower aerobic biological reaction zone, the upper aerobic biological reaction zone is connected with the channel formed between the left partition baffle (11) and the partition baffle (10), the bottom of the upper aerobic biological reaction zone is provided with the first water distribution plate (12), and the immobilized aerobic denitrifying bacteria balls (13) are stacked above the first water distribution plate (12), the upper aerobic biological reaction zone is communicated with the ecological treatment zone (2) through the channel formed between the right side of the biological treatment zone (1) and the right partition baffle (14); The first pad (5) and the second pad (6) in the lower aerobic biological reaction zone are single-edge butt-jointed and sealed, and closely adhere to the inner wall bottom surface of the lower aerobic biological reaction zone, the other edges of the first pad (5) and the second pad (6) are respectively sealed with the wall of the lower aerobic biological reaction zone, the first pad (5) forms an angle of 10° with the bottom surface of the lower aerobic biological reaction zone, and the second pad (6) forms an angle of 20°-30° with the bottom surface of the lower aerobic biological reaction zone; The upper plate surface of the water distribution flow guide plate (4) is connected with the left wall of the biological treatment zone (1), and the lower plate surface is parallelly arranged with the first pad (5); The first air distribution pipe (7) is arranged on the sealing line of the first pad (5) and the second pad (6), the second air distribution pipe (8) is arranged at the abutting position of the second pad (6) and the right wall of the biological treatment zone (1), the first air distribution pipe (7) and the second air distribution pipe (8) are both provided with aeration round holes and are arranged in a straight line, the aeration hole direction of the first air distribution pipe (7) is parallel to the second pad (6), and the aeration hole direction of the second air distribution pipe (8) is vertically upward; The immobilized aerobic denitrifying bacteria balls (13) are composed of the aerobic denitrifying composite microbial agent which is embedded, separated, screened and compounded by polyvinyl alcohol, sodium alginate and solid carbon source powder as immobilization materials; The lower aerobic biological reaction zone is filled with activated carbon and Fe3O4, and the optimal loading ratio of activated carbon and Fe3O4 is 2:1, the modified suspended filler (9) is in the shape of a round sheet with a diameter of 1-3 cm and a thickness of 0.5-1 cm, and the packing density of the modified suspended filler (9) in the lower aerobic biological reaction zone is 0.5-2.5 kg / m 3 .

2. The device according to claim 1, characterized in that: The bottom of the ecological treatment zone (2) is provided with the second water distribution plate (15), and the top right side of the ecological treatment zone (2) is provided with the water outlet pipe (21). The ratio of the distance and length of the second water distribution plate (15) from the bottom surface of the ecological treatment area (2) is 0.005, the first water distribution plate (12) is uniformly provided with a circular hole above, and the hole diameter is 5mm, and the porosity is 0.4-0.5; the second water distribution plate (15) is uniformly provided with a gap above, and the gap length is 5cm, the width is 2cm, and the porosity is 0.3-0.

4.

3. The device according to claim 2, wherein: The second water distribution plate (15) is provided with gravel (16), cinder (17) and soil medium (19) from bottom to top, the contact surface of the cinder (17) and the soil medium (19) is paved with a barrier plate (18), and the soil medium (19) is planted with emergent plants (20).

4. The device according to claim 1, wherein: The first water distribution plate (12) and the partition baffle (10) form a channel; the channel between the partition baffle (10) and the left wall of the biological treatment area (1), the channel between the partition baffle (10) and the left partition (11), the channel between the first water distribution plate (12) and the partition baffle (10), and the channel between the right wall of the biological treatment area (1) and the right partition (14) are all equal in width to the biological treatment area (1) and the ecological treatment area (2); the biological treatment area (1) and the ecological treatment area (2) are equal in width, the length ratio is 1: (2-3), and the height ratio is (2-3):

1.

5. The device according to claim 1, wherein: The optimal proportion of the immobilized material is 10.103% of polyvinyl alcohol, 1.548% of sodium alginate and 0.732% of solid carbon source powder, the immobilized aerobic denitrifying bacteria ball (13) has a diameter of 5-10 mm and a density of 1.09×103 g / cm 3 , and the stacking thickness of the immobilized aerobic denitrifying bacteria ball (13) in the upper aerobic biological reaction zone is 3-5 cm.

6. The device according to claim 1, wherein: The filling height of the gravel (16), the cinder (17) and the soil medium (19) in the ecological treatment area (2) is equal.

7. A method of treating sewage water in a decentralized biological-ecological combined treatment plant according to any one of claims 1-6, characterized in that: The method comprises the following steps: S1. The lower aerobic reaction zone of the biological treatment zone (1) is a sufficient aerobic environment, and the enrichment and attachment of aerobic microorganisms can be achieved through the activated carbon and Fe3O4 modified suspended filler (9). Under the action of the modified suspended filler (9) and the attached aerobic microorganisms, the pollutants in the water are filtered, adsorbed and degraded through physical, chemical and microbial processes. Most of the COD in the wastewater is degraded by heterotrophic aerobic microorganisms, and NH4+ - N in the wastewater is converted to NO3- - N by the attached autotrophic nitrifying bacteria group on the modified suspended filler (9), thereby achieving the preliminary purification of the wastewater; S2. The pre-purified sewage enters the upper aerobic reaction zone and fully contacts with the "bed" of immobilized aerobic denitrifying bacteria balls (13). Due to the thin thickness of the bed and the "open type" of the upper aerobic reaction zone, natural reoxygenation can be carried out, thereby maintaining a low aerobic environment, and the residual COD in the wastewater and the NO3- - N are all introduced into the interior of the bacteria balls through the pore channels of the immobilized aerobic denitrifying bacteria balls (13), thereby fully contacting with the aerobic denitrifying bacteria agent. The aerobic denitrifying bacteria uses the residual COD in the wastewater as a carbon source to reduce N2 to escape, thereby achieving intermediate carbon and nitrogen removal purification of the wastewater. S3. The wastewater after medium purification further enters the ecological treatment area (2), and under the physical adsorption and chemical precipitation of the gravel (16), the cinder (17) and the soil medium (19), part of the phosphorus pollutants can be removed; then the wastewater enters the root zone of the emergent plants (20) through the gap of the barrier plate (18), under the physical enclosure of the barrier plate (18), the rich root system of the plants can only grow horizontally into a "root wall", the thick and dense "root wall" and the rich microbial flora attached thereto can fully absorb the residual nitrogen and phosphorus pollutants in the wastewater as nutrient substances in the growth process, so that the ultimate purification of the wastewater is realized and finally discharged up to the standard.

8. The treatment method according to claim 7, characterized in that: The oxygen concentration of the aerobic environment in S1 is >5mg / L; the oxygen concentration of the low-oxygen environment of the aerobic denitrifying bacteria in S2 is 2-5mg / L.

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