UASB (Upflow Anaerobic Sludge Blanket) reactor based on denitrification of sulfur cycle biological system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUNAN DEEYA ENVIRONMENTAL ENG CO LTD
- Filing Date
- 2025-05-08
- Publication Date
- 2026-05-12
AI Technical Summary
In existing wastewater denitrification processes, biological methods require the addition of a large amount of carbon source, increasing operating costs and sludge production. Furthermore, traditional UASB reactors consume a large amount of organic carbon during the removal of nitrate nitrogen, resulting in high complexity.
The UASB reactor based on sulfur cycle biological system denitrification is adopted. Sulfate-reducing bacteria reduce sulfate to sulfide as an electron donor, while sulfur autotrophic denitrifying bacteria reduce nitrate to nitrogen. Combined with constant temperature water bath and three-phase separator, efficient denitrification under low carbon-to-nitrogen ratio is achieved, reducing the use of carbon source.
Under low carbon-to-nitrogen ratio conditions, it achieves efficient removal of nitrates and COD from wastewater, reduces operating costs, decreases sludge production and greenhouse gas emissions, and achieves a denitrification efficiency of over 90%.
Smart Images
Figure CN224226811U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of anaerobic biological wastewater treatment technology, and in particular to a UASB reactor based on sulfur cycle biological system denitrification. Background Technology
[0002] There are many types of wastewater denitrification processes. Many industries use wastewater containing high concentrations of nitrates. Nitrates entering water bodies not only cause eutrophication, but also negatively impact aquatic life and human production and daily life. Currently, commonly used wastewater denitrification processes include physicochemical methods and biological methods. Physicochemical methods mainly include ion exchange, electrodialysis, and reverse osmosis, but these are rarely used due to their high cost. While heterotrophic denitrification in biological methods has been widely applied and can achieve good denitrification results, it usually requires the addition of large amounts of carbon sources, which increases operating costs and process complexity. Furthermore, it leads to higher sludge production and greenhouse gas emissions. Currently, the most widely used industry application is sulfur cycle biological system denitrification technology. Compared to other denitrification technologies, sulfur cycle biological system denitrification uses inexpensive and readily available reduced sulfides as electron donors, is less affected by water quality, and is easily utilized.
[0003] Upflow anaerobic sludge blanket (UASB) is a common anaerobic biological wastewater treatment device, widely used in the biological treatment of organic wastewater. However, the wastewater has a complex composition and excessive total nitrogen. The process of removing nitrate nitrogen requires the consumption of a large amount of organic carbon and control of reaction conditions.
[0004] Therefore, this application proposes a UASB reactor based on sulfur cycle biological system denitrification. In the process of treating nitrogen-containing wastewater using the UASB reactor, the sulfur cycle biological system denitrification technology can reduce the use of carbon sources under low carbon-to-nitrogen ratio conditions, thereby reducing operating costs. The sulfur cycle biological system denitrification technology uses sulfate as the main sulfur source, and introduces sulfate-reducing bacteria to reduce sulfate to sulfides for use by autotrophic bacteria. Moreover, the UASB reactor integrates biological reaction and precipitation separation, with a simple structure and convenient operation. Utility Model Content
[0005] In view of the shortcomings of traditional wastewater denitrification methods, a UASB reactor based on sulfur cycle biological system denitrification is provided, which can effectively remove pollutants such as COD, nitrate or nitrate nitrogen from wastewater, meet the needs of centralized treatment of nitrogen-containing wastewater, and effectively improve the anaerobic biological treatment efficiency of nitrogen-containing wastewater.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A UASB reactor based on sulfur cycle biological system denitrification includes: a reactor column, a bottom cover detachably connected to the bottom of the reactor column, and a three-phase separator detachably connected to the top of the reactor column;
[0008] The reactor column has a double-cavity structure, with the inner cavity serving as the reaction zone and the outer cavity serving as the constant-temperature water bath zone. The constant-temperature water bath zone is independently separated from the reaction zone.
[0009] The bottom cover is provided with a water inlet;
[0010] The three-phase separator is equipped with an exhaust port, a water outlet, and a sampling port;
[0011] The reactor contains, from bottom to top, a sludge layer, a suspended layer, and a sedimentation zone consisting of the three-phase separator. The reactor is equipped with a defoaming device, which includes a scum baffle installed at the outlet to intercept granular sludge containing air bubbles.
[0012] Optionally, the reactor column is provided with a movable plate inside, which is fixed to the reactor column by a limiting ring block, thereby achieving a seal on the reactor column when the movable plate is fixed.
[0013] Optionally, the constant temperature water bath area is connected to an external constant temperature water bath tank via a hot water circulation pump to form a closed-loop temperature control system.
[0014] Optionally, the sludge layer may contain a complex microbial community of sulfate-reducing bacteria and sulfur-autotrophic denitrifying bacteria.
[0015] Optionally, the reactor inlet is connected to the raw water tank via a peristaltic pump, and the inlet pipeline is equipped with an adjustable flow gate valve.
[0016] Optionally, the bottom of the reactor column is provided with a sludge circulation pump connection port for returning sludge to the suspension layer.
[0017] Optionally, the scum baffle is a detachable mesh structure with a pore size of less than 0.5 mm, used to intercept sludge and allow liquid to pass through.
[0018] Alternatively, the reactor column may be a component made of acrylic material.
[0019] Optionally, the reactor column and the bottom cover, as well as the reactor column and the three-phase separator, are connected by flange structures.
[0020] Optionally, the surface of the three-phase separator is coated with a hydrophobic coating to enhance gas-liquid separation efficiency.
[0021] The advantages of this utility model are:
[0022] 1. The design of the constant temperature water bath zone can provide the optimal temperature for microbial reaction. At the same time, the design of the three-phase separator has the characteristics of good separation effect, smooth drainage and relatively centralized exhaust volume calculation, which can effectively remove pollutants such as nitrates and COD from wastewater.
[0023] 2. The flange structure allows for easy and quick assembly and disassembly of the reactor column, three-phase separator, and bottom cover;
[0024] 3. The reactor column is equipped with a movable plate inside. When the movable plate is fixed, the inside of the reactor column is sealed to prevent the mud-water mixture inside the reactor column from flowing out.
[0025] 4. A scum baffle is installed at the outlet of the three-phase separator to effectively intercept the sludge that floats during the mud-water separation process. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments 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.
[0027] Figure 1 This is a schematic diagram of the UASB reactor structure described in this utility model;
[0028] Figure 2 This is a diagram showing the application status of the UASB reactor described in this utility model. Detailed Implementation
[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0030] Example 1
[0031] like Figures 1-2As shown, a UASB reactor based on sulfur cycle biological system denitrification includes: a reactor column 1, a bottom cover 2 detachably connected to the bottom of the reactor column 1, and a three-phase separator 3 detachably connected to the top of the reactor column 1; the reactor column 1 has a double-cavity structure, with the inner cavity serving as the reaction zone and the outer cavity serving as the constant temperature water bath zone, which is independently separated from the reaction zone; the bottom cover 2 is provided with an inlet 21; the three-phase separator 3 is provided with an exhaust port 31, an outlet 32, and a sampling port 33; the interior of the reactor is provided with a sludge layer, a suspended layer, and a sedimentation zone composed of the three-phase separator 3 from bottom to top; the reactor is provided with a defoaming device, which includes a scum baffle installed at the outlet 32 for intercepting granular sludge containing air bubbles.
[0032] Specifically, nitrogen-containing wastewater enters the reactor column 1 through the inlet 21 of the bottom cover 2. During the ascent, it passes through the sludge layer and the suspended layer in sequence. In the sludge layer, sulfate-reducing bacteria reduce sulfate to sulfide, and sulfur autotrophic denitrifying bacteria use sulfide as an electron donor to reduce nitrate to nitrogen. The three-phase separator 3 separates the nitrogen generated by the reaction, the treated clean water and sludge. The gas is discharged from the exhaust port 31, the clean water flows out from the outlet 32, and the sludge returns to the reaction zone. The scum baffle intercepts the sludge particles carried by the air bubbles to prevent sludge loss.
[0033] Example 2
[0034] like Figures 1-2 As shown, a UASB reactor based on sulfur cycle biological system denitrification includes: a reactor column 1, a bottom cover 2 detachably connected to the bottom of the reactor column 1, and a three-phase separator 3 detachably connected to the top of the reactor column 1; the reactor column 1 has a double-cavity structure, with the inner cavity serving as the reaction zone and the outer cavity serving as the constant temperature water bath zone, which is independently separated from the reaction zone; the bottom cover 2 is provided with an inlet 21; the three-phase separator 3 is provided with an exhaust port 31, an outlet 32, and a sampling port 33; the interior of the reactor is provided with a sludge layer, a suspended layer, and a sedimentation zone composed of the three-phase separator 3 from bottom to top; the reactor is provided with a defoaming device, which includes a scum baffle installed at the outlet 32 for intercepting granular sludge containing air bubbles.
[0035] Furthermore, the reactor column 1 is equipped with a movable plate inside, which is fixed to the reactor column 1 by a limiting ring block. With the movable plate fixed, the reactor column 1 is sealed. The movable plate forms a physical barrier, ensuring the reactor's airtightness during operation. When maintenance is required, the limiting ring block can be released to remove the movable plate, preventing sewage leakage and improving operational safety.
[0036] Furthermore, the constant temperature water bath zone is connected to the external constant temperature water bath tank 7 via a hot water circulation pump 8, forming a closed-loop temperature control system. The constant temperature water bath zone, connected to the external constant temperature water bath tank 7 via the hot water circulation pump 8, allows circulating water to flow between the two chambers, absorbing or releasing heat to maintain a constant temperature in the reaction zone and ensure the optimal temperature for microbial reaction.
[0037] Furthermore, the sludge layer contains a composite microbial community of sulfate-reducing bacteria and sulfur-autotrophic denitrifying bacteria. In the sludge layer, sulfate-reducing bacteria reduce sulfate to sulfides, while sulfur-autotrophic denitrifying bacteria use sulfides as electron donors to reduce nitrates to nitrogen gas. The synergistic effect of this composite microbial community achieves highly efficient nitrogen removal at a low carbon-to-nitrogen ratio (C / N ≤ 1.5), with a removal rate ≥ 90%, while simultaneously reducing the need for external carbon sources, lowering sludge production, and reducing greenhouse gas emissions.
[0038] Furthermore, the reactor inlet 21 is connected to the raw water tank 4 via a peristaltic pump 5, and an adjustable flow gate valve is installed in the inlet pipeline. The peristaltic pump 5 quantitatively delivers nitrogen-containing wastewater from the raw water tank 4 to the inlet 21, and the gate valve adjusts the flow rate to match the preset hydraulic residence time, enabling precise flow control and optimizing reaction conditions.
[0039] Furthermore, the bottom of the reactor column 1 is provided with a sludge circulation pump connection port for returning sludge to the suspended layer. The sludge circulation pump draws the settled sludge back to the suspended layer through the sludge circulation pump port 11 at the bottom, maintaining the sludge concentration in the reactor. Sludge return can enhance microbial activity and improve denitrification efficiency.
[0040] Furthermore, the scum baffle is a detachable mesh structure with a pore size of less than 0.5 mm, used to intercept sludge while allowing liquid to pass through. The design of the scum baffle prevents sludge loss and its detachable structure facilitates cleaning.
[0041] Furthermore, the reactor column 1 is a component made of acrylic material. The acrylic reactor column 1 has high light transmittance and corrosion resistance, allowing direct observation of the internal sludge distribution and reaction state. The reactor column 1 is connected to the bottom cover 2 and the three-phase separator 3 via flange bolts, with corrosion-resistant sealing gaskets embedded between the flanges, enabling quick assembly and disassembly.
[0042] Furthermore, the reactor column 1 and the bottom cover 2 are connected by flange structures as well as the reactor column 1 and the three-phase separator 3.
[0043] Furthermore, the surface of the three-phase separator 3 is covered with a hydrophobic coating to enhance gas-liquid separation efficiency.
[0044] Example 3
[0045] like Figures 1-2As shown, the working steps and principle of the above-mentioned UASB reactor are as follows: Nitrogenous wastewater containing reaction reagents is poured into the raw water tank, and then the water in the raw water tank is injected into the UASB reactor column through the inlet by a peristaltic pump for denitrification reaction. The organic matter in the wastewater is decomposed by microorganisms in the activated sludge, and the sludge falls back into the sludge suspension zone. After separation, the wastewater is collected and discharged to the clear water tank through the outlet.
[0046] 34L of nitrogen-containing wastewater, along with certain carbon sources such as glucose, sulfur sources such as anhydrous sodium sulfate, and nitrogen sources such as potassium nitrate, were injected into a UASB reactor to ensure that the potassium nitrate content in the reactor was 60mg / L. The hydraulic retention time was set to 24h. Then, the reactor was run for five days each with C / N ratios of 1.7, 1.6, 1.5, and 1.4. The results showed that the nitrate nitrogen removal rate could reach over 90% in all cases. Considering the overall denitrification efficiency and resource consumption analysis, the C / N ratio of 1.5 was the best, with a maximum denitrification rate of 95.6%.
[0047] With C / N set to 1.5, the reactor was run five times each with hydraulic retention times of 24 hours, 12 hours, 8 hours, and 6 hours. The results showed that, except for 6 hours, the denitrification rate could reach over 90% for the other retention times. Considering both denitrification efficiency and time loss, the best effect was achieved with a retention time of 8 hours, reaching a maximum of 93.75%.
[0048] In summary, nitrogen-containing wastewater can achieve efficient denitrification by operating in a UASB reactor at a carbon-to-nitrogen ratio of 1.5 for 8 hours.
[0049] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. A UASB reactor based on sulfur cycle biological system denitrification, characterized in that, include: The reactor column, the bottom cover detachably connected to the bottom of the reactor column, and the three-phase separator detachably connected to the top of the reactor column; The reactor column has a double-cavity structure, with the inner cavity serving as the reaction zone and the outer cavity serving as the constant-temperature water bath zone. The constant-temperature water bath zone is independently separated from the reaction zone. The bottom cover is provided with a water inlet; The three-phase separator is equipped with an exhaust port, a water outlet, and a sampling port; The reactor contains, from bottom to top, a sludge layer, a suspended layer, and a sedimentation zone consisting of the three-phase separator. The reactor is equipped with a defoaming device, which includes a scum baffle installed at the outlet to intercept granular sludge containing air bubbles.
2. The UASB reactor according to claim 1, characterized in that, The reactor column is equipped with a movable plate inside. The movable plate is fixed to the reactor column by a limiting ring block, thereby achieving a seal on the reactor column when the movable plate is fixed.
3. The UASB reactor according to claim 1, characterized in that, The constant temperature water bath area is connected to an external constant temperature water bath tank via a hot water circulation pump, forming a closed-loop temperature control system.
4. The UASB reactor according to claim 1, characterized in that, The sludge layer contains a complex microbial community of sulfate-reducing bacteria and sulfur-autotrophic denitrifying bacteria.
5. The UASB reactor according to claim 1, characterized in that, The reactor's inlet is connected to the raw water tank via a peristaltic pump, and the inlet pipeline is equipped with an adjustable flow gate valve.
6. The UASB reactor according to claim 1, characterized in that, The bottom of the reactor column is equipped with a sludge circulation pump connection port for returning sludge to the suspension layer.
7. The UASB reactor according to claim 1, characterized in that, The scum baffle is a detachable mesh structure with a pore size of less than 0.5 mm, used to intercept sludge and allow liquid to pass through.
8. The UASB reactor according to claim 1, characterized in that, The reactor column is a component made of acrylic material.
9. The UASB reactor according to claim 1, characterized in that, The reactor column and the bottom cover are connected by flange structures, as are the reactor column and the three-phase separator.
10. The UASB reactor according to claim 1, characterized in that, The surface of the three-phase separator is covered with a hydrophobic coating to enhance gas-liquid separation efficiency.