A sludge-membrane symbiotic system capable of reducing sludge discharge
By introducing heavy sludge screeners and centrifuges into the sludge membrane symbiosis system, combined with an anaerobic sludge digestion reactor, the problems of sludge reduction and carbon self-sufficiency were solved, achieving deep removal of pollutants and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU XINGRONG ENVIRONMENT CO LTD
- Filing Date
- 2025-07-25
- Publication Date
- 2026-07-10
AI Technical Summary
Existing sludge membrane symbiosis systems have limited sludge reduction effects, limited microbial enrichment capacity over long sludge ages, and require frequent addition of carbon sources to ensure nitrogen and phosphorus removal efficiency.
By introducing a heavy sludge screener and a heavy sludge return pipe into the sludge membrane symbiosis system, combined with a centrifuge and an anaerobic digestion reactor for sludge, the separation and return of heavy sludge are achieved. The microorganisms in the heavy sludge are used to improve the biological nitrogen and phosphorus removal capacity, and the external carbon source is replaced by EPS return and VFAs return, thereby reducing operating costs.
It achieves sludge reduction, carbon self-sufficiency, and deep removal of pollutants, improves biological nitrogen and phosphorus removal capacity, and reduces system operating costs.
Smart Images
Figure CN224478006U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a sludge film symbiosis system that can reduce sludge discharge. Background Technology
[0002] The activated sludge process is a wastewater treatment technology that uses organic pollutants in wastewater as a substrate. Under dissolved oxygen conditions, it removes organic matter through continuous cultivation of microbial communities via processes such as coagulation, adsorption, oxidative decomposition, and sedimentation. However, traditional activated sludge processes suffer from problems such as large sludge production, low nitrogen and phosphorus removal efficiency, and strong carbon source dependence.
[0003] Therefore, a sludge-film symbiotic system combining biofilm and activated sludge has been developed to replace the activated sludge process. Compared to the activated sludge process, the sludge-film symbiotic system has two microbial growth modes, resulting in a richer variety of microorganisms and stronger adaptability to changes in water quality and quantity. Therefore, it can more effectively remove pollutants such as organic matter, nitrogen, and phosphorus by utilizing the synergistic effect of microorganisms with different growth modes under different environmental conditions, and the treatment effect is relatively more stable.
[0004] However, while existing sludge-film co-existing systems can improve nitrogen and phosphorus removal efficiency, their sludge reduction effect is not significant. Furthermore, these systems have limited capacity to enrich long-aged microorganisms (such as anaerobic ammonia-oxidizing bacteria), resulting in poor deep pollutant removal. In addition, existing sludge-film co-existing systems require frequent addition of carbon sources during operation to ensure effective nitrogen and phosphorus removal. Utility Model Content
[0005] The purpose of this invention is to provide a sludge membrane symbiosis system that can reduce sludge discharge, achieve sludge reduction, carbon self-sufficiency, and deep removal of pollutants.
[0006] The technical solution of this utility model to solve the above-mentioned technical problems is: a sludge film symbiosis system that can reduce sludge discharge, including a sewage treatment tank and a secondary sedimentation tank. The sewage treatment tank is divided into an anaerobic zone, an anoxic zone and an aerobic zone along the sewage flow direction. The bottom of the secondary sedimentation tank is connected to the inlet of a heavy sludge screen through a sludge output pipe. The heavy sludge outlet of the heavy sludge screen is connected to the anaerobic zone through a heavy sludge return pipe. The light sludge outlet of the heavy sludge screen is connected to the inlet of a centrifuge through a light sludge conveying pipe a. The supernatant outlet of the centrifuge is connected to the anoxic zone through an EPS return pipe. A light sludge conveying pipe b is connected to the sludge outlet of the centrifuge.
[0007] As a further improvement of this utility model, the output end of the light sludge conveying pipe b is connected to the inlet of the sludge anaerobic digestion reactor, the supernatant outlet of the sludge anaerobic digestion reactor is connected to the EPS return pipe through the VFAs return pipe, and a sludge discharge pipe is connected to the sludge outlet of the sludge anaerobic digestion reactor.
[0008] As a further improvement of this utility model, the sludge anaerobic digestion reactor is also connected to a PAC input pipe.
[0009] As a further improvement of this utility model, a VFAs return pump is provided on the VFAs return pipe.
[0010] As a further improvement of this utility model, the bottom of the aerobic zone is connected to the anoxic zone through a mixed liquid return pipe, and a mixed liquid return pump is provided on the mixed liquid return pipe.
[0011] As a further improvement of this utility model, a heavy sludge return pump is provided on the heavy sludge return pipe.
[0012] As a further improvement of this utility model, a light sludge conveying pipe a is provided with a light sludge conveying pump.
[0013] As a further improvement of this utility model, an EPS return pump is provided on the EPS return pipe.
[0014] As a further improvement of this utility model, a sewage inlet pipe is connected to the anaerobic zone, and the output end of the heavy sludge return pipe is connected to the sewage inlet pipe.
[0015] As a further improvement of this utility model, biological packing columns are provided in both the anoxic zone and the aerobic zone.
[0016] Beneficial effects
[0017] Compared with existing technologies, the advantages of the sludge film symbiosis system of this invention, which can reduce sludge discharge, are as follows:
[0018] 1. In this system, the heavy sludge is separated from the secondary sedimentation tank by a combination of a heavy sludge screen and a heavy sludge return pipe, and then returned to the anaerobic zone of the wastewater treatment tank. During this process, the polyphosphate-accumulating bacteria, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying heterotrophic bacteria, and anaerobic ammonia-oxidizing bacteria contained in the heavy sludge will increase the microbial concentration in the biological treatment tank, improve the settling performance of the biological treatment tank, and thus greatly enhance the biological nitrogen and phosphorus removal capacity, thereby achieving deep removal of pollutants. At the same time, this significantly reduces the amount of sludge discharged from the system. In addition, by using a centrifuge device in conjunction with an EPS return pipe, the EPS obtained from centrifuging the light sludge can be returned to the anoxic zone, thereby replacing the external carbon source and reducing the system operating cost.
[0019] The present invention will become clearer from the following description and in conjunction with the accompanying drawings, which are used to explain the embodiments of the present invention. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of this utility model.
[0022] Wherein: 1-Anaerobic zone; 11-Sewage inlet pipe; 2-Anoxic zone; 3-Aerobic zone; 31-Mixed liquor return pipe; 32-Mixed liquor return pump; 4-Secondary sedimentation tank; 41-Sludge output pipe; 5-Heavy sludge screener; 51-Heavy sludge return pipe; 52-Light sludge conveying pipe a; 53-Light sludge conveying pump; 54-Heavy sludge return pump; 6-Centrifuge device; 61-EPS return pipe; 62-Light sludge conveying pipe b; 63-EPS return pump; 7-Sludge anaerobic digestion reactor; 71-PAC input pipe; 72-VFAs return pipe; 73-VFAs return pump; 74-Sludge discharge pipe; 8-Biological packing column. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0025] Embodiments of the present invention will now be described with reference to the accompanying drawings.
[0026] Example:
[0027] The specific embodiments of this utility model are as follows: Figure 1 As shown, a sludge-film symbiotic system that reduces sludge discharge includes a wastewater treatment tank and a secondary sedimentation tank 4. The secondary sedimentation tank 4 is located downstream of and connected to the wastewater treatment tank. The specific connection between the wastewater treatment tank and the secondary sedimentation tank 4 is a conventional technique in this field and will not be described in detail in this embodiment. The wastewater treatment tank is divided into an anaerobic zone 1, an anoxic zone 2, and an aerobic zone 3 along the wastewater flow direction. Biological packing columns 8 are installed in both the anoxic zone 2 and the aerobic zone 3. By arranging biological packing columns 8 in the anoxic zone 2 and the aerobic zone 3, a stable and efficient biofilm can be constructed to enrich microorganisms, thereby promoting the growth of long-lived microorganisms, such as heterotrophic denitrifying microorganisms and anaerobic ammonia-oxidizing bacteria, which in turn increases the effective sludge concentration and forms simultaneous denitrification inside and outside the biofilm.
[0028] In this system, the bottom of the secondary sedimentation tank 4 is connected to the inlet of the heavy sludge screen 5 via a sludge output pipe 41. The heavy sludge outlet of the heavy sludge screen 5 is connected to the anaerobic zone 1 via a heavy sludge return pipe 51. Specifically, the anaerobic zone 1 is connected to a wastewater inlet pipe 11, and the output end of the heavy sludge return pipe 51 is connected to the wastewater inlet pipe 11. Furthermore, a heavy sludge return pump 54 is installed on the heavy sludge return pipe 51 for returning the heavy sludge. In this embodiment, the heavy sludge screen 5 can be an existing off-the-shelf product. Through the cooperation of the heavy sludge screen 5 and the heavy sludge return pipe 51, the heavy sludge in the secondary sedimentation tank 4 can be separated and returned to the anaerobic zone 1 of the wastewater treatment tank. In this process, the polyphosphate-accumulating bacteria, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying heterotrophic bacteria, and anaerobic ammonia-oxidizing bacteria contained in the heavy sludge will increase the microbial concentration in the biological treatment tank, improve the settling performance of the biological treatment tank, and thus greatly enhance the biological nitrogen and phosphorus removal capacity, thereby achieving deep removal of pollutants. At the same time, the recycling and reuse of heavy sludge also significantly reduces the amount of sludge discharged from the final system.
[0029] Meanwhile, the light sludge outlet of the heavy sludge screen 5 is connected to the inlet of the centrifuge 6 via a light sludge conveying pipe a52. A light sludge conveying pump 53 is installed on the light sludge conveying pipe a52 to transport the light sludge into the centrifuge. Simultaneously, the supernatant outlet of the centrifuge 6 is connected to the anoxic zone 2 via an EPS return pipe 61. An EPS return pump 63 is also installed on the EPS return pipe 61 to return the EPS—the extracellular polymeric substance of activated sludge—to the anoxic zone 2. Additionally, a light sludge conveying pipe b62 is connected to the sludge outlet of the centrifuge 6. In this embodiment, the centrifuge 6 can be a readily available off-the-shelf product.
[0030] The light sludge separated by the heavy sludge screen 5 is pumped to the centrifuge 6 by the light sludge transfer pump 53. Centrifugal force peels the EPS off the sludge surface, forming a supernatant that is returned to the anoxic zone 2. In the anoxic zone 2, denitrifying bacteria utilize the organic matter released by the EPS as electron donors for biological denitrification, achieving in-situ carbon release and online utilization of the sludge EPS in the main process. This replaces external carbon sources and reduces system operating costs.
[0031] In addition, to further achieve carbon self-sufficiency and reduce sludge discharge, the output end of the light sludge conveying pipe b62 of this system is connected to the inlet of the sludge anaerobic digestion reactor 7. The supernatant outlet of the sludge anaerobic digestion reactor 7 is connected to the EPS return pipe 61 via a VFAs return pipe 72, and a VFAs return pump 73 is installed on the VFAs return pipe 72 to return VFAs—volatile fatty acids—to the anoxic zone 2. A sludge discharge pipe 74 is connected to the sludge outlet of the sludge anaerobic digestion reactor 7. Furthermore, a PAC input pipe 71 is also connected to the sludge anaerobic digestion reactor 7. In this embodiment, the sludge anaerobic digestion reactor 7 can be an existing off-the-shelf product.
[0032] Light sludge from centrifuge unit 6 enters anaerobic digestion reactor 7, where it undergoes in-situ digestion, rapidly forming a homogeneous state after cell wall disruption. Subsequently, by controlling reaction conditions such as pH and temperature, the anaerobic digestion is kept at the hydrolysis-acidification stage, maximizing the yield of volatile fatty acids. Simultaneously, PAC (polyaluminum chloride) is added to anaerobic digestion reactor 7 through PAC inlet pipe 71 to remove total phosphorus and large, recalcitrant products from the mixed liquor, ultimately yielding a supernatant rich in volatile fatty acids. This supernatant, rich in volatile fatty acids, is recycled to anoxic zone 2 for online utilization as an internal carbon source, further achieving carbon self-sufficiency and reducing the cost of externally purchased carbon sources. Furthermore, because the light sludge converts some recalcitrant organic matter into volatile fatty acids during the hydrolysis-acidification stage, the amount of sludge discharged from the system is further reduced.
[0033] It is important to note that:
[0034] In this embodiment, the bottom of the aerobic zone 3 is connected to the anoxic zone 2 through the mixed liquid return pipe 31, and the mixed liquid return pipe 31 is equipped with a mixed liquid return pump 32.
[0035] The present invention has been described above in conjunction with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations made in accordance with the essence of the present invention.
Claims
1. A sludge-film symbiotic system that reduces sludge discharge, comprising a wastewater treatment tank and a secondary sedimentation tank (4), wherein the wastewater treatment tank is divided into an anaerobic zone (1), an anoxic zone (2), and an aerobic zone (3) along the wastewater flow direction, characterized in that, The bottom of the secondary sedimentation tank (4) is connected to the inlet of the heavy sludge screen (5) through the sludge output pipe (41). The heavy sludge outlet of the heavy sludge screen (5) is connected to the anaerobic zone (1) through the heavy sludge return pipe (51). The light sludge outlet of the heavy sludge screen (5) is connected to the inlet of the centrifuge device (6) through the light sludge conveying pipe a (52). The supernatant outlet of the centrifuge device (6) is connected to the anoxic zone (2) through the EPS return pipe (61). The sludge outlet of the centrifuge device (6) is connected to the light sludge conveying pipe b (62).
2. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, The output end of the light sludge conveying pipe b (62) is connected to the inlet of the sludge anaerobic digestion reactor (7). The supernatant outlet of the sludge anaerobic digestion reactor (7) is connected to the EPS return pipe (61) through the VFAs return pipe (72). A sludge discharge pipe (74) is connected to the sludge outlet of the sludge anaerobic digestion reactor (7).
3. The sludge film symbiosis system for reducing sludge discharge according to claim 2, characterized in that, The sludge anaerobic digester (7) is also connected to a PAC input pipe.
4. The sludge film symbiosis system for reducing sludge discharge according to claim 2 or 3, characterized in that, The VFAs return pipe (72) is equipped with a VFAs return pump (73).
5. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, The bottom of the aerobic zone (3) is connected to the anoxic zone (2) through a mixed liquid return pipe (31), and a mixed liquid return pump (32) is provided on the mixed liquid return pipe (31).
6. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, The heavy sludge return pipe (51) is equipped with a heavy sludge return pump (54).
7. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, The light sludge conveying pipe a (52) is equipped with a light sludge conveying pump (53).
8. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, An EPS return pump (63) is provided on the EPS return pipe (61).
9. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, The anaerobic zone (1) is connected to a sewage inlet pipe (11), and the output end of the heavy sludge return pipe (51) is connected to the sewage inlet pipe (11).
10. The sludge film symbiosis system for reducing sludge discharge according to claim 1, characterized in that, Biological packing columns (8) are provided in both the anoxic zone (2) and the aerobic zone (3).