Anaerobic sewage treatment device

Abstract

An anaerobic sewage treatment device comprises a reactor main body. The upper part of the inner cavity of the reactor main body is provided with a two-stage three-phase separation system, the two-stage three-phase separation system comprises a lower inclined plate precipitation layer and a composite gas chamber structure which is positioned above the lower inclined plate precipitation layer and is formed by vertically overlapping a positive cone and an inverted cone, the positive cone and the inverted cone share a central gas chamber, and the top of the central gas chamber is closed and is communicated with the outside through a biogas outlet pipe; an annular peripheral water outlet system is arranged above the two-stage three-phase separation system and surrounds the periphery of the two-stage three-phase separation system, the annular peripheral water outlet system comprises an annular triangular water outlet weir and a water outlet pipe, the inner edge of the top of the water outlet weir is provided with a circular foam breaking plate with conical thorns, and the sharp ends of the conical thorns point downwards to the liquid level so as to break foam and weaken the false liquid level influence; preferably, an annular baffle is arranged to form a steady-flow water outlet area, and a latticed perforated pipe water distribution system is arranged at the bottom. The device can strengthen sludge interception and gas collection separation, stabilize circumferential overflow effluent, improve effluent clarity and reduce sludge loss, and is suitable for treatment of high-concentration and refractory wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sewage and wastewater treatment, and particularly relates to a high-efficiency anaerobic biological treatment device for treating high-concentration organic wastewater, especially petrochemical wastewater, and is particularly suitable for industrial wastewater treatment scenarios containing high-concentration sulfate, refractory organic matter and suspended solids. BACKGROUND

[0002] Petrochemical wastewater has the characteristics of high organic matter concentration (COD can reach 5000-50000 mg / L), high toxicity, poor biodegradability, and high content of sulfur compounds and oil substances. The conventional activated sludge method has low treatment efficiency, high energy consumption, and is prone to sludge bulking. In recent years, anaerobic digestion technology has been widely used in petrochemical wastewater treatment due to its low energy consumption, high volumetric loading, and biogas production.

[0003] The existing anaerobic reactors (such as UASB, EGSB, IC reactors) have the following problems: (1) The water distribution system design is unreasonable, resulting in uneven water flow distribution, short flow or dead zones, affecting the treatment efficiency; (2) The separation effect of the three-phase separator is poor, and the sludge is easy to be lost, and the gas collection rate is low; (3) The effluent system is easily affected by bubble disturbance, resulting in turbid effluent and excessive suspended solids, affecting the subsequent process; (4) There is a lack of effective bubble destruction mechanism for the liquid surface, affecting gas collection and system stability.

[0004] Therefore, there is an urgent need for a new type of anaerobic wastewater treatment device with optimized structure, stable operation, high separation efficiency, and strong impact load resistance, to improve the treatment efficiency and system reliability of petrochemical wastewater. SUMMARY

[0005] Anaerobic reactors offer advantages such as low energy consumption and biogas production in treating high-concentration organic wastewater, but they often face challenges in engineering operation, including insufficient three-phase separation and unstable effluent interfaces. Specifically, the large amount of biogas produced during anaerobic reactions easily carries sludge flocs to the surface. If the solid-liquid and gas-liquid separation capabilities at the top of the reactor are insufficient, sludge can be easily carried away with the effluent, increasing the suspended solids in the effluent and consequently causing a decrease in system biomass and fluctuations in treatment performance. At the same time, the foam layer on the liquid surface tends to accumulate near the weir and form a "false liquid level," causing an unreal rise in the overflow elevation, resulting in uneven effluent, increased weir disturbance, and further exacerbation of entrainment and fluctuations. To address the aforementioned problems, this invention provides an anaerobic wastewater treatment device. It features a two-stage three-phase separation system installed in the upper part of the reactor's main body, surrounded by an annular effluent system. A circular bubble-breaking plate with conical spikes is installed along the inner edge of the top of the annular triangular effluent weir. This allows foam to be broken in time during the circumferential overflow process, reducing the impact of the foam layer on the overflow level. This synergizes with the annular triangular effluent weir to achieve a more stable circumferential effluent and reduce the risk of sludge entrainment. The two-stage three-phase separation system consists of a lower inclined plate sedimentation layer and an upper composite gas chamber structure formed by superimposed positive and inverted cones. The positive and inverted cones share a central gas chamber and are connected to a biogas outlet pipe to enhance gas-liquid-solid separation and gas collection and guidance effects.

[0006] To achieve the above objectives, the present invention provides an anaerobic wastewater treatment device, including a reactor body, wherein a two-stage three-phase separation system is provided in the upper part of the inner cavity of the reactor body, and an annular circumferential effluent system is provided above the two-stage three-phase separation system and around its outer periphery. The two-stage three-phase separation system includes an inclined plate sedimentation layer at the bottom and a composite gas chamber structure formed by stacking positive and inverted cones above the inclined plate sedimentation layer. The positive and inverted cones share a central gas chamber, the top of which is sealed and connected to the outside of the reactor body through a biogas outlet pipe. The annular circumferential water discharge system includes an annular triangular water discharge weir and a water discharge pipe connected to the annular triangular water discharge weir. The inner edge of the top of the annular triangular water discharge weir is provided with a circular bubble-breaking plate with cone-shaped spikes. The tips of the cone-shaped spikes point downwards towards the liquid surface inside the reactor body, so as to break the foam on the liquid surface during the circumferential overflow water discharge process and reduce the influence of the foam layer on the overflow liquid level, thereby cooperating with the annular triangular water discharge weir to achieve stable circumferential water discharge.

[0007] In some technical solutions, the annular flow outlet system further includes an annular baffle. The annular baffle is disposed on the outer periphery of the positive cone and located on the inner side of the annular triangular outlet weir. The annular baffle and the annular triangular outlet weir are spaced apart to define and form an annular steady flow outlet zone, so that the liquid after two-stage three-phase separation is evenly distributed circumferentially at the front edge of the annular triangular outlet weir and the disturbance of air bubbles and floating objects to the weir opening is reduced.

[0008] In some technical solutions, the annular triangular outlet weir is composed of multiple triangular weir openings continuously distributed along the circumference, and the crest elevation of the triangular weir openings is consistent; and / or, The bottom of the annular triangular effluent weir is provided with a collection tank, and the effluent pipe is connected to the collection tank to lead the clarified effluent out of the reactor body.

[0009] In some technical solutions, the spikes are evenly distributed on the circular bubble-breaking plate, the diameter of the spikes is 2 to 5 mm, and the tip of the spikes maintains a gap of 5 ± 1 mm with the running liquid surface.

[0010] In some technical solutions, the inclined plate sedimentation layer is composed of a plurality of inclined plates, and satisfies at least one of the following: (2) The inclination angle of the inclined plate is 50° to 60°, and the plate spacing between adjacent inclined plates is 30 to 50 mm; (2) The inclined plate is a polypropylene inclined plate or an ABS inclined plate with a surface that has been hydrophilically modified.

[0011] In some technical solutions, the upright cone is a cone that is thinner at the top and thicker at the bottom, and the inverted cone is a cone that is thicker at the top and thinner at the bottom. The angle between the cone surface of the upright cone and the horizontal plane is 55° to 65°, and the angle between the cone surface of the inverted cone and the horizontal plane is 115° to 135°.

[0012] In some technical solutions, a water distribution system is provided at the bottom of the inner cavity of the reactor body. The water distribution system includes a main water inlet pipe connected to the water inlet pipe and multiple perforated pipes connected to the main water inlet pipe. Each perforated pipe is provided with multiple water distribution holes, and the perforated pipes are arranged in a cross pattern to form a grid-like water distribution area.

[0013] In some technical solutions, the water distribution holes of each perforated pipe are opened at an angle downwards, and the openings of the water distribution holes face the central axis of the reactor body to form a center-pointing umbrella-shaped jet water distribution.

[0014] In some technical solutions, the water distribution holes are set in a staggered 45° downward angle, and the hole spacing is 80-120 mm and the hole diameter is Φ4-6 mm.

[0015] Some technical solutions also include at least one of the following structures: A composite packing layer located below the two-stage three-phase separation system within the reactor body; The anti-corrosion layer on the inner wall of the reactor body is either a carbon steel lining FRP anti-corrosion layer or a polyethylene anti-corrosion layer. The sludge discharge port at the bottom of the reactor body is used to periodically discharge accumulated sludge.

[0016] Compared with existing anaerobic reactors that only employ single three-phase separation or rely solely on weir overflow, the present invention has at least the following advantages: 1. In this invention, the two-stage three-phase separation system first intercepts and re-settles the sludge flocs entrained in the upward flow in the inclined plate sedimentation layer, and then completes gas-liquid separation and gas collection and guidance in the composite gas chamber formed by the superposition of positive and inverted cones. This reduces the probability of biogas entraining liquid and sludge rising upwards, reduces sludge loss with the effluent, and helps maintain the stability of the reactor biomass. The annular circumferential flow effluent system uses an annular triangular effluent weir to achieve uniform circumferential overflow. A circular bubble-breaking plate with cone-shaped spikes is set along the inner edge of the top of the weir, with the spike tips pointing downwards towards the liquid surface. During the overflow process, it breaks the foam, weakens the influence of false liquid levels, avoids abnormal rise in the water level in front of the weir and fluctuations in the effluent, and reduces the risk of entrainment caused by weir disturbance. Therefore, the synergistic effect of two-stage three-phase separation and annular flow effluent enables the device to significantly improve sludge retention and gas collection efficiency, increase effluent clarity, reduce sludge loss, and extend stable operation cycle under high-concentration, recalcitrant petrochemical wastewater and other high-gas-producing and easily impacted operating conditions, thereby achieving a comprehensive effect of reasonable structure, high-efficiency operation, and excellent effluent quality.

[0017] 2. In this invention, by setting an annular baffle on the outer periphery of the positive cone and the inner side of the annular triangular outlet weir, and by making the annular baffle and the annular triangular outlet weir alternate to form an annular stable flow outlet zone, circumferential buffering and uniform distribution can be achieved before the liquid enters the weir, further reducing the direct disturbance of air bubbles and floating objects to the weir, making the circumferential overflow more stable, and helping to further reduce water fluctuation and entrainment.

[0018] 3. In this invention, by setting a grid-like water distribution area at the bottom of the reactor cavity, consisting of a main water inlet pipe and multiple cross-perforated pipes, and coordinating the orientation and angle of the water distribution holes, more uniform bottom water distribution and more thorough turbulent mixing can be achieved, reducing the risk of short-circuiting and the formation of local dead zones, and providing more stable hydraulic conditions and reaction environment for upper three-phase separation and stable effluent.

[0019] 4. This invention achieves full-link optimization of water inlet distribution, solid-liquid-gas separation, and effluent interface stability: On the one hand, uniform water distribution effectively eliminates short-circuiting and local dead zones, enhances mass transfer and mixing conditions in the reaction zone, and improves organic matter degradation efficiency by about 15-20%; on the other hand, the two-stage three-phase separation system performs graded interception and reflux sedimentation of sludge carried by the upflow, significantly reducing sludge loss with water and controlling the sludge loss rate to below 3%, thereby maintaining high biomass and enhancing resistance to shock loads; at the same time, the annular baffle and bubble-breaking plate form a stable flow buffer in front of the weir and promptly break the foam, weakening false liquid levels and weir disturbances, making the circumferential overflow more stable, and the effluent suspended solids (SS) can be consistently below 20 mg / L for a long time, and excellent effluent quality can be obtained without additional filtration under most operating conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings and their markings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. 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 anaerobic wastewater treatment device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the two-stage three-phase separation system described in an embodiment of the present invention; Figure 3 This is a schematic diagram of the annular flow water outlet system described in an embodiment of the present invention; Figure 4 This is a schematic diagram of the water distribution system according to an embodiment of the present invention.

[0022] The meanings of the symbols in the diagram are as follows: 1—Reactor body; 2—Water distribution system: 2a—Main water inlet pipe, 2b—Perforated pipe, 2c—Water distribution hole; 3—Two-stage three-phase separation system: 3a—Inclined plate sedimentation layer, 3b—Inverted cone, 3c—Right cone; 4—Circular flow water outlet system: 4a—Circular baffle, 4b—Circular triangular water outlet weir, 4c—Water outlet pipe, 4d—Circular bubble-breaking plate; 5—Composite packing layer; 6—Biogas outlet pipe; 7—Water inlet pipe; 8—Sludge discharge port. Detailed Implementation

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0024] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0025] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0026] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] In one embodiment, such as Figure 1 The anaerobic wastewater treatment device of the present invention includes a reactor body 1. The reactor body 1 forms an internal cavity space for anaerobic reaction. A two-stage three-phase separation system 3 is arranged in the upper part of the internal cavity of the reactor body 1, and an annular circumferential effluent system 4 is arranged above the two-stage three-phase separation system 3 and around its outer periphery. By concentrating the key solid-liquid separation, gas-liquid separation, and effluent stabilization and defoaming structures in the upper region of the reactor body 1, the gas, liquid and sludge flocs carried by the upward flow during the anaerobic reaction can be separated and stabilized sequentially before reaching the effluent boundary. This reduces the impact of sludge entrainment, effluent fluctuations and foam false liquid levels on the overflow elevation, improves effluent clarity and is conducive to the stable maintenance of biomass in the reactor.

[0029] In specific design, such as Figure 2The two-stage three-phase separation system 3 includes a lower inclined plate sedimentation layer 3a and a composite gas chamber structure above it. The inclined plate sedimentation layer 3a is used to intercept and guide the sludge flocs entrained in the upward flow, causing the sludge flocs to accumulate on the surface of the inclined plate and flow back to the reaction zone under gravity, thereby reducing the solid entrainment load before entering the upper gas chamber. In a preferred embodiment, the composite gas chamber structure is formed by stacking a positive cone 3c and an inverted cone 3b. The positive cone 3c and the inverted cone 3b share a central gas chamber, the top of which is closed and connected to the outside of the reactor body 1 through a biogas outlet pipe 6. By sharing a central gas chamber and connecting it to the biogas outlet pipe 6, the biogas produced by the anaerobic reaction can be effectively collected and discharged within the composite gas chamber structure. At the same time, the guiding and separation space formed by the cone structure reduces the probability of bubbles carrying liquid and sludge upwards, thereby reducing the risk of sludge loss with the effluent.

[0030] In specific implementation, such as Figure 3 The annular effluent system 4 includes an annular triangular effluent weir 4b and an effluent pipe 4c connected to the annular triangular effluent weir 4b. The annular triangular effluent weir 4b is used to achieve circumferential overflow water intake, allowing the clarified liquid to enter the effluent weir more evenly along the circumference and be discharged through the effluent pipe 4c, thus providing a basis for effluent stability. Furthermore, a circular bubble-breaking plate 4d with conical spikes is provided on the inner edge of the top of the annular triangular effluent weir 4b, with the tips of the spikes pointing downwards towards the liquid surface inside the reactor body 1. During the circumferential overflow effluent process, the bubble-breaking plate can break the foam on the liquid surface and weaken the false liquid level effect caused by the foam layer, thereby avoiding abnormal rise in the water level in front of the weir and effluent fluctuations caused by foam accumulation, and reducing the risk of sludge entrainment caused by weir disturbance. Thus, the two-stage three-phase separation system 3 and the annular effluent system 4 form a structural synergy, enabling the device to maintain good solid-liquid separation effect and effluent stability even under conditions of high gas production, easy foaming, or large load fluctuations.

[0031] In optimal implementation, such as Figure 3 To further stabilize the hydraulic conditions upstream of the weir and suppress direct disturbances to the weir opening by floating debris and air bubbles, the annular circumferential flow discharge system 4 can also be equipped with an annular baffle 4a, with a height of 150–200 mm. This annular baffle 4a is positioned on the outer periphery of the equilateral cone 3c and inside the annular triangular discharge weir 4b. The annular baffle 4a and the annular triangular discharge weir 4b are spaced apart to define an annular stable flow discharge zone. Through the formation of this annular stable flow discharge zone, the liquid after two-stage three-phase separation can be buffered and evenly distributed circumferentially before entering the annular triangular discharge weir 4b, thereby reducing the impact disturbances of air bubbles and floating debris on the weir opening, making the circumferential overflow more stable, and further reducing discharge fluctuations and entrainment risks.

[0032] In a further preferred embodiment, the annular triangular effluent weir 4b can be composed of multiple triangular weir openings continuously distributed circumferentially, with each weir opening having the same crest elevation. This continuous circumferential distribution of the weir openings and the consistent crest elevation improves the uniformity of the circumferential overflow and reduces fluctuations caused by localized short-circuit overflows. Specifically, a collection trough can be installed at the bottom of the annular triangular effluent weir 4b, with the effluent pipe 4c connected to this collection trough to collect the clarified effluent and lead it out of the reactor body 1, thereby achieving stable collection and discharge of the overflow effluent and reducing the impact of localized scouring and backflow disturbances on the stability in front of the weir.

[0033] In one embodiment, to achieve both bubble-breaking and flow-stabilizing effects, the cones are evenly distributed on the circular bubble-breaking plate 4d, with a diameter of 2–5 mm and a gap of 5 ± 1 mm between the cone tips and the operating liquid surface. This allows for effective rupture of the foam film without contact with the liquid surface, reducing disturbance to the circumferential overflow flow and minimizing the impact of the foam layer on the overflow level, thereby improving effluent stability and clarity. Specifically, the diameter of the circular bubble-breaking plate 4d is slightly smaller than the inner diameter of the annular triangular outlet weir 4b, and the bubble-breaking plate is made of corrosion-resistant stainless steel or high-density polyethylene. It should be understood that the specific shape, density, and distribution of the cones can be adjusted to suit the bubble-breaking function, and the bubble-breaking plate can also adopt a fixed or detachable structure for easy installation and maintenance.

[0034] In the specific design, the inclined plate sedimentation layer 3a consists of several inclined plates arranged at an angle, and can satisfy at least one of the following: First, the inclination angle of the inclined plates is 50° to 60°, and the plate spacing between adjacent inclined plates is 30 to 50 mm; Second, the inclined plates are polypropylene inclined plates or ABS inclined plates with hydrophilic modification treatment on the surface. By reasonably setting the inclination angle and plate spacing of the inclined plates, a guiding and settling path that is conducive to the settling and reflux of flocs can be formed, thereby improving the solid-liquid separation efficiency. Furthermore, the use of hydrophilic modified surfaces can enhance the wetting and capture capacity of floating sludge flocs, reduce the probability of sludge being carried upward with the water flow, thereby helping to reduce sludge loss and improve the effluent clarity.

[0035] In a preferred embodiment, to optimize the matching relationship between the gas guiding and separation space of the composite gas chamber, the upright cone 3c can be a cone that is thinner at the top and thicker at the bottom, and the inverted cone 3b can be a cone that is thicker at the top and thinner at the bottom. The angle between the cone surface of the upright cone 3c and the horizontal plane is 55°–65°, and the angle between the cone surface of the inverted cone 3b and the horizontal plane is 115°–135°. Through the matching of the above cone shapes and angle ranges, the upright cone 3c is more conducive to converging the rising gas towards the central gas chamber and guiding it upwards, while the inverted cone 3b is conducive to providing a relatively larger gas-liquid separation space and reducing the entrainment of rising bubbles, thereby promoting sludge recirculation and sedimentation and improving the stability of gas-liquid separation.

[0036] In one alternative embodiment, such as Figure 4A water distribution system 2 can be installed at the bottom of the inner cavity of the reactor body 1 to improve water inlet distribution and enhance the hydraulic conditions of the reaction zone. This water distribution system 2 includes a main water inlet pipe 2a connected to the inlet pipe 7 and multiple perforated pipes 2b connected to the main water inlet pipe 2a. Each perforated pipe has multiple water distribution holes 2c, and the multiple perforated pipes 2b are arranged in a cross pattern to form a grid-like water distribution area. By covering the bottom section of the reactor with the grid-like water distribution area, the uniformity of water inlet distribution can be improved and the risk of short-circuiting can be reduced, thus providing a more stable hydraulic foundation for the upper two-stage three-phase separation and stable circumferential effluent. Furthermore, the water distribution holes 2c of each perforated pipe can be opened obliquely downwards, with the orifices of the water distribution holes 2c facing the central axis of the reactor body 1, to form a center-pointing umbrella-shaped jet water distribution, thereby enhancing local disturbance and mixing while ensuring uniform water distribution, and reducing sedimentation and dead zone formation. In a preferred embodiment, the water distribution holes 2c are arranged in a staggered, downward-sloping 45° pattern, with a hole spacing of 80–120 mm and a hole diameter of Φ4–6 mm, to achieve a better balance between water distribution coverage, jet disturbance, and structural strength. It should be understood that, provided the requirements for uniform water distribution and anti-clogging are met, the number, arrangement, and hole parameters of the main inlet pipe 2a and the perforated pipe 2b can be adjusted accordingly.

[0037] In a further optional embodiment, the device may also include at least one of the following structures to improve engineering adaptability and operational reliability: First, a composite packing layer 5 is provided inside the reactor body 1 below the two-stage three-phase separation system 3 to provide an attachment carrier for anaerobic microorganisms and increase effective biomass, thereby enhancing treatment capacity and improving resistance to shock loads; Second, an anti-corrosion layer is provided on the inner wall of the reactor body 1, which may be a carbon steel-lined FRP anti-corrosion layer or a polyethylene anti-corrosion layer to adapt to corrosive wastewater environments and improve device durability; Third, a sludge discharge port 8 is provided at the bottom of the reactor body 1 for periodically discharging accumulated sludge to maintain effective volume and operational stability. The above-mentioned additional structures can be flexibly selected according to the scale of the device, the corrosivity of the wastewater, the characteristics of sludge accumulation, and maintenance strategies, and do not constitute a limitation on the core structural synergy of the present invention.

[0038] To better understand and apply the above scheme and to effectively demonstrate its corresponding benefits, the anaerobic wastewater treatment device provided by the present invention will be further described below in conjunction with specific embodiments.

[0039] Example 1 Pretreated petrochemical wastewater (screening, grit removal, pH adjustment) is fed into the bottom of the reactor body through inlet pipe 7, and then evenly sprayed into the anaerobic reaction zone via water distribution system 2 at a 45° downward angle. During its ascent, the wastewater comes into full contact with the high-concentration anaerobic sludge and composite packing material, decomposing organic matter into methane and carbon dioxide.

[0040] The rising mixed liquor undergoes initial solid-liquid separation in the inclined plate sedimentation layer, with sludge settling and returning; it then enters the composite gas chamber, where the gas is effectively collected and discharged through the biogas outlet pipe 6, while the liquid phase continues to rise to the effluent zone.

[0041] After the effluent passes through the annular baffle to intercept fine suspended solids, it flows smoothly into the annular triangular effluent weir. Under the interference of the circular bubble-breaking plate, the bubbles on the liquid surface are forced to break, and the effluent is discharged through the effluent pipe in a laminar flow state. The effluent SS < 15 mg / L and COD removal rate ≥ 85%.

[0042] During operation, the sludge discharge port 8 is opened periodically to remove accumulated sludge. The system employs constant temperature control, maintaining a temperature of 36±1℃. Actual measurements show that, under conditions of influent COD of 15000 mg / L and HRT of 24 h, the COD removal rate reaches 88%, and the biogas production rate is 0.45 L / gCOD, which is far superior to traditional anaerobic reactors.

[0043] Example 2 Taking the actual production wastewater of a large petrochemical enterprise as the treatment object, the wastewater has the following typical characteristics: influent COD concentration: 5000-15000 mg / L; influent pH value: 7.0-7.5; temperature conditions: constant temperature control at 36±1℃; hydraulic retention time: HRT=22-24h; The reactor body is designed with a volume of 150m³, and the specific configuration is as follows: Reactor body inner diameter: 6.0m, height: 12.0m; Bottom water distribution system 2: 4 perforated pipes, pipe diameter 120mm, perforation spacing 100mm; Two-stage three-phase separation system 3: First stage inclined plate sedimentation layer 24 pieces, inclined plate angle 50°, spacing 40mm; Second stage positive cone angle: 65°, inverted cone angle: 130°; Annular circumferential flow effluent system 4: Annular baffle height 180mm; After pretreatment, the wastewater, with its pH adjusted to 7.0±0.2, enters the reactor body. Water is evenly distributed via a 45° downward angled jet through the water distribution system 2. Each perforated pipe has a Φ5mm orifice for water distribution, and the spray angle is precisely controlled. A high sludge concentration (MLSS=15-20g / L) is maintained within the reactor body, and a composite packing layer 5 provides a biological carrier to increase biomass. After 6 months of continuous and stable operation, the system exhibits the following excellent performance, with the following effluent water quality indicators: COD removal rate: ≥87%; SS removal rate: ≥95%; pH value: 6.9-7.3; sludge loss rate: <2.5%, far lower than the 5-8% of traditional reactors; biogas production: 0.48L / gCOD, with gas production stability ≥92%.

[0044] Example 3 The examples illustrate the treatment of petrochemical wastewater containing high concentrations of sulfates and suspended solids, which has the following typical characteristics: Influent COD concentration: 12000-18000 mg / L; Influent sulfate concentration: 1500-2500 mg / L; Influent suspended solids concentration: 800-1200 mg / L; Influent pH value: 7-7.5; Temperature conditions: constant temperature control at 36±1℃; Hydraulic retention time: HRT=24-26h.

[0045] The reactor body is designed with a volume of 80m³, and the specific configuration is as follows: Reactor body inner diameter: 4.5m, height: 9.0m; Bottom water distribution system 2: 4 cross-perforated pipes, pipe diameter 100mm, perforation spacing 120mm; Two-stage three-phase separation system 3: First stage inclined plate sedimentation layer 16 pieces, inclined plate angle 55°, spacing 45mm; Second stage positive cone angle: 60°, inverted cone angle: 125°; Circular flow effluent system 4: Circular baffle height 160mm; Composite packing layer 5 adopts self-developed attapulgite composite carrier, and the packing amount is 2% of the effective volume of the reactor body.

[0046] Pretreatment stage: After the wastewater is pretreated by the screen and grit chamber, the pH value is adjusted to 7-7.3 to ensure that the wastewater is suitable for anaerobic treatment.

[0047] Water distribution optimization: A water distribution system 2 with 45° downward staggered perforated pipes is adopted to ensure uniform distribution of high-concentration sulfate wastewater and avoid the inhibitory effect caused by excessive local sulfate concentration.

[0048] Sulfate Reduction: Under anaerobic conditions, sulfate-reducing bacteria (SRB) reduce sulfate to sulfides, while organic matter is degraded. By controlling the dissolved oxygen level within the reactor body and providing a sufficient organic carbon source, the sulfate reduction process can be optimized to achieve a sulfate removal rate of ≥85%.

[0049] Suspended solids removal: The composite packing layer 5 provides a large number of microbial attachment points. Suspended solids form a biofilm on the surface of the packing, and are removed through biodegradation and physical interception. The suspended solids removal rate is ≥90%.

[0050] Three-phase separation: The two-stage three-phase separation system achieves effective separation of sludge, gas and liquid, with sludge loss rate controlled at <2%, ensuring stable system operation.

[0051] After three months of continuous and stable operation, the system demonstrated the following excellent performance: COD removal rate: ≥88%, effluent COD ≤1500 mg / L.

[0052] Sulfate removal rate: ≥85%, effluent sulfate ≤350 mg / L.

[0053] Suspended solids removal rate: ≥90%, effluent SS ≤100 mg / L.

[0054] pH value: 6.8-7.2, stable operation.

[0055] Sludge loss rate: <2%, sludge concentration maintained at 18-22 g / L.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An anaerobic wastewater treatment device, characterized in that: The reactor body includes a two-stage three-phase separation system in the upper part of the inner cavity of the reactor body, and an annular circumferential flow water system is provided above the two-stage three-phase separation system and around its outer periphery. The two-stage three-phase separation system includes an inclined plate sedimentation layer at the bottom and a composite gas chamber structure formed by stacking positive and inverted cones above the inclined plate sedimentation layer. The positive and inverted cones share a central gas chamber, the top of which is sealed and connected to the outside of the reactor body through a biogas outlet pipe. The annular circumferential water discharge system includes an annular triangular water discharge weir and a water discharge pipe connected to the annular triangular water discharge weir. The inner edge of the top of the annular triangular water discharge weir is provided with a circular bubble-breaking plate with cone-shaped spikes. The tips of the cone-shaped spikes point downwards towards the liquid surface inside the reactor body, so as to break the foam on the liquid surface during the circumferential overflow water discharge process and reduce the influence of the foam layer on the overflow liquid level, thereby cooperating with the annular triangular water discharge weir to achieve stable circumferential water discharge.

2. The anaerobic wastewater treatment device according to claim 1, characterized in that: The annular flow outlet system also includes an annular baffle, which is disposed on the outer periphery of the positive cone and located on the inner side of the annular triangular outlet weir. The annular baffle and the annular triangular outlet weir are spaced apart to define and form an annular steady flow outlet zone, so that the liquid after two-stage three-phase separation is evenly distributed circumferentially before entering the annular triangular outlet weir and the disturbance of air bubbles and floating objects to the weir opening is reduced.

3. The anaerobic wastewater treatment device according to claim 1 or 2, characterized in that: The annular triangular outlet weir is composed of multiple triangular weir openings continuously distributed along the circumference, and the crest elevations of the triangular weir openings are consistent; and / or, The bottom of the annular triangular effluent weir is provided with a collection tank, and the effluent pipe is connected to the collection tank to lead the clarified effluent out of the reactor body.

4. The anaerobic wastewater treatment device according to claim 1, characterized in that: The cones are evenly distributed on the circular bubble-breaking plate. The diameter of the cones is 2-5 mm, and there is a gap of 5 ± 1 mm between the tip of the cone and the running liquid surface.

5. The anaerobic wastewater treatment device according to claim 1, characterized in that: The inclined plate sedimentation layer consists of a plurality of inclined plates arranged at an angle, and satisfies at least one of the following: (1) The inclination angle of the inclined plate is 50° to 60°, and the plate spacing between adjacent inclined plates is 30 to 50 mm; (2) The inclined plate is a polypropylene inclined plate or an ABS inclined plate with a surface that has been hydrophilically modified.

6. The anaerobic wastewater treatment device according to claim 1, characterized in that: The upright cone is a cone that is thinner at the top and thicker at the bottom, and the inverted cone is a cone that is thicker at the top and thinner at the bottom. The angle between the cone surface of the upright cone and the horizontal plane is 55° to 65°, and the angle between the cone surface of the inverted cone and the horizontal plane is 115° to 135°.

7. The anaerobic wastewater treatment device according to claim 1, characterized in that: The bottom of the inner cavity of the reactor body is provided with a water distribution system. The water distribution system includes a main water inlet pipe connected to the water inlet pipe and multiple perforated pipes connected to the main water inlet pipe. Each perforated pipe is provided with multiple water distribution holes, and the perforated pipes are arranged in a cross pattern to form a grid-like water distribution area.

8. The anaerobic wastewater treatment device according to claim 7, characterized in that: The water distribution holes of each of the perforated pipes are opened at an angle downwards, and the openings of the water distribution holes face the central axis of the reactor body to form a central umbrella-shaped jet water distribution.

9. The anaerobic wastewater treatment device according to claim 8, characterized in that: The water distribution holes are set in a staggered 45° downward angle, with a hole spacing of 80-120mm and a hole diameter of Φ4-6mm.

10. The anaerobic wastewater treatment device according to claim 1, characterized in that: It also includes at least one of the following structures: A composite packing layer located below the two-stage three-phase separation system within the reactor body; The anti-corrosion layer on the inner wall of the reactor body is either a carbon steel lining FRP anti-corrosion layer or a polyethylene anti-corrosion layer. The sludge discharge port at the bottom of the reactor body is used to periodically discharge accumulated sludge.

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