An integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery
By designing an integrated anaerobic biological wastewater treatment device, combined with a three-dimensional water distributor and siphon pipe, the automated recovery of fatty acids was achieved, solving the problems of complex structure and high energy consumption of existing devices, and improving treatment efficiency and land utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHWEST JIAOTONG UNIV
- Filing Date
- 2025-05-26
- Publication Date
- 2026-07-21
AI Technical Summary
Existing wastewater treatment and fatty acid extraction equipment is complex in structure, consumes a lot of energy, and occupies a large area.
Design an integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery, comprising a reaction chamber, a water distributor, an anaerobic reaction zone, a fatty acid recovery zone, and a gas collection chamber. Employ a three-dimensional water distributor, a variable-diameter annular distribution pipe, and an inverted U-shaped siphon to achieve automated fatty acid recovery and fully automated regeneration of anion exchange resin.
It achieves automated recovery of fatty acids, reduces energy consumption, improves the efficiency of anaerobic acidification reaction, reduces the footprint of the equipment, has a compact structure, and is easy to operate.
Smart Images
Figure CN120483434B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wastewater treatment technology, and particularly to anaerobic biological wastewater treatment technology. Specifically, it relates to an integrated device for anaerobic biological wastewater treatment coupled with fatty acid recovery. Background Technology
[0002] In industrial wastewater treatment, achieving wastewater purification while simultaneously converting organic matter in the wastewater into high-value-added products is a significant challenge. Food processing and oilseed processing wastewater contains large amounts of fatty acids; recovering these fatty acids can not only reduce environmental pollution but also recycle resources and reduce carbon emissions.
[0003] Among wastewater treatment technologies, anaerobic biological treatment technology has developed rapidly in recent years. Anaerobic biological treatment technology utilizes facultative anaerobic and anaerobic microbial communities under anaerobic conditions to convert organic matter into methane and carbon dioxide. It has been widely applied in the treatment of high-concentration organic wastewater, such as brewery wastewater, papermaking wastewater, and food processing wastewater.
[0004] The basic structure of the anaerobic biological treatment device includes a corrosion-resistant reaction chamber containing an anaerobic sludge bed. The reactor is a cylindrical reaction chamber with an inlet pipe and distributor at the bottom. The anaerobic sludge bed is positioned above the distributor. During operation, wastewater enters the bottom of the reactor through a uniform distribution system and undergoes biodegradation via the anaerobic sludge bed from bottom to top. Finally, a three-phase separator removes solid waste and collects biogas and liquid. For a more detailed explanation of the anaerobic treatment principle and the reaction chamber structure, please refer to the technical solution disclosed in Chinese Patent Publication No. CN114394665A.
[0005] Extracting fatty acids during wastewater treatment aligns perfectly with current trends in environmental protection technology. Chinese Patent Publication No. CN119685439A discloses a method and apparatus for in-situ screening of microbial communities and anaerobic acid production enrichment based on selective metal ion removal. The main problems with existing wastewater treatment and fatty acid extraction devices are their complex structure, high energy consumption, and large footprint. Summary of the Invention
[0006] The main purpose of this application is to provide an integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery, so as to solve the problems of complex structure and high energy consumption of existing wastewater treatment and fatty acid extraction devices.
[0007] To achieve the above objectives, according to one aspect of a specific embodiment of this application, an integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery is provided, comprising a reaction chamber, a water distributor at the bottom of the reaction chamber and a gas collection chamber at the top, an anaerobic reaction zone above the water distributor, the anaerobic reaction zone being filled with anaerobic granular sludge, wastewater being evenly distributed through the water distributor and entering the anaerobic reaction zone for treatment, and gas generated during the treatment process being collected in the gas collection chamber; characterized in that a fatty acid recovery zone is provided at the top of the anaerobic reaction zone, and an isolation device is installed between the anaerobic reaction zone and the fatty acid recovery zone to control the isolation and opening of the anaerobic reaction zone and the fatty acid recovery zone; the fatty acid recovery zone is filled with anion exchange resin and equipped with a regenerated liquid injection device and a fatty acid absorber, the regenerated liquid injection device being used to inject regenerated liquid, and the fatty acid absorber being used to recover fatty acids; the isolation device is composed of two identical circular stainless steel plates, the two stainless steel plates being concentrically arranged and both having through holes, one stainless steel plate being fixed, and the other stainless steel plate being able to rotate at a certain angle; the fatty acid absorber is a cross-shaped recovery pipe.
[0008] In some embodiments, the reaction chamber is cylindrical.
[0009] In some embodiments, the regenerant injection device includes a variable-diameter annular distribution pipe and a filling pipe; the variable-diameter annular distribution pipe is used to uniformly distribute the regenerant, and the filling pipe is connected to the variable-diameter annular distribution pipe for inputting the regenerant.
[0010] In some embodiments, the variable diameter annular distribution pipe is a stainless steel pipe, which forms a ring. The two ends of the ring's diameter are connected to the filling pipe. The stainless steel pipe has a gradually changing diameter, with a smaller diameter at the connection point with the filling pipe, gradually expanding towards both ends.
[0011] In some embodiments, a drainage device is installed above the fatty acid recovery zone to drain the liquid when the liquid level reaches a set position.
[0012] In some embodiments, the drainage device is composed of an inverted U-shaped siphon tube, which uses the siphon effect to discharge liquid.
[0013] In some embodiments, the gas collection chamber is equipped with a pressure regulating valve to work in conjunction with an inverted U-shaped siphon to control liquid discharge.
[0014] In some embodiments, the regenerated solution is a mixture of NaOH and NaCl.
[0015] In some embodiments, the mixture contains 0.5 mol / L NaOH and 1.0 mol / L NaCl.
[0016] According to the technical solution of this application and the technical solution further improved therein in some exemplary embodiments, this application has the following beneficial effects: The system achieves automated fatty acid recovery and fully automated anion exchange resin regeneration. Treated wastewater discharge is achieved through gravity flow without external power, making it both energy-efficient and highly effective. A three-dimensional water distributor ensures more uniform wastewater distribution, improving the efficiency of the anaerobic acidification reaction. The use of a variable-diameter annular distribution pipe further enhances the uniformity of the regenerated liquid distribution, better suited to the adsorption of the anion exchange resin. The entire device, from bottom to top, includes an inlet zone, an anaerobic reaction zone, a fatty acid recovery zone, an outlet zone, and a gas collection zone; its compact structure and small footprint make it highly efficient.
[0017] The present application will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present application. Attached Figure Description
[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The detailed embodiments, illustrative examples, and descriptions thereof are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a plan view of Embodiment 1 of this application; Figure 2 yes Figure 1 Top view; Figure 3 This is a structural schematic diagram of Example 1; Figure 4a This is a schematic diagram of the grid plate and telescopic sealing skirt structure in Example 1; Figure 4b yes Figure 4a AA section view; Figure 5a This is a top view of the regenerant injection device in Example 1; Figure 5b This is a schematic diagram of the regenerated liquid injection device in Example 1; Figure 5c yes Figure 5b BB cross-sectional view; Figure 6 This is a schematic diagram of the recovery tube structure in Example 1; Figure 7a This is a cross-sectional view of the isolation device in the isolation state of Embodiment 2; Figure 7b This is a cross-sectional view of the isolation device in the open state of Embodiment 2.
[0019] In the diagram: I is the inlet zone; II is the anaerobic reaction zone; III is the fatty acid recovery zone; IV is the outlet zone; V is the gas collection chamber; 1 is the inlet pipe; 2 is the three-dimensional water distributor; 3 is the outlet pipe; 4 is the telescopic sealing skirt; 40 is the support; 5 is the grid plate; 6 is the recovery pipe; 7 is the anion exchange resin; 8 is the filling pipe; 80 is the variable diameter annular distribution pipe; 9 is the inverted U-shaped siphon pipe; 10 is the gas outlet pipe; 11 is the gas collection pipe; 12 is the gas collection chamber; 13 is the pressure reducing valve; 50 is the through hole; 51 and 52 are stainless steel plates; 100 is the reaction chamber. Detailed Implementation
[0020] It should be noted that, unless otherwise specified, the specific embodiments, exemplary embodiments, and features thereof in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and the following description.
[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the specific embodiments and exemplary embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described exemplary embodiments are only some embodiments of the present application, and not all embodiments. Based on the specific embodiments and exemplary embodiments of the present application, all other embodiments and implementations obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.
[0022] The technical solution of this application adds a fatty acid recovery zone to the reaction chamber of the anaerobic biological treatment device for wastewater, making full use of the fatty acids produced by hydrolysis and acidification reactions during the anaerobic treatment process, and collecting and recovering fatty acids by ion exchange adsorption.
[0023] Example 1 The technical solution of this application will be further described and illustrated below with reference to the accompanying drawings and embodiments.
[0024] like Figure 1-3 As shown, the integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery of this application includes a reaction chamber 100. The reaction chamber 100 has an overall cylindrical shape with a height H = 3300 mm and a bottom cylindrical diameter R = 2000 mm. The reaction chamber includes, from bottom to top, an inlet zone I, an anaerobic reaction zone II, a fatty acid recovery zone III, an effluent zone IV, and a gas collection zone V. Except for the inlet zone, the height ratio of each functional zone is II:III:IV:V = 4:4:2:1, and the volume ratio is II:III:IV:V = 2:2:2:1.
[0025] The specific structure is as follows: The inlet zone I is located at the bottom of the reaction chamber 100 and is equipped with an inlet pipe 1 with a diameter of 100 mm. The inlet pipe 1 is connected to the water distributor 2. The water distributor 2 is a three-dimensional water distributor. It is installed 200 mm away from the bottom of the anaerobic reaction zone and is arranged in a radial branching pattern to ensure uniform distribution of wastewater.
[0026] Anaerobic reaction zone II is located above the water distributor and is filled with anaerobic granular sludge. An isolation device is installed at the top of anaerobic reaction zone II to separate the anaerobic reaction zone from the fatty acid recovery zone during fatty acid recovery. In this example, the isolation device includes a grid plate 5 and a silicone rubber telescopic sealing skirt 4. The grid plate 5 has a 10 mm aperture to isolate the anaerobic sludge. Below the grid plate 5, a silicone rubber telescopic sealing skirt 4 is installed, with an outer diameter 20 mm larger than the grid plate 5 (total outer diameter 2000 mm), and is connected to a pneumatic drive system (including pistons, cylinders, solenoid valves, etc.). The grid plate 5 and the silicone rubber telescopic sealing skirt 4 together constitute the isolation device in this example. Air pressure control of inflation and deflation allows for the switching between isolated and open states. After inflation, the upper part of the silicone rubber sealing skirt 4 tightly adheres to the grid plate 5, blocking the grid plate's openings, while the lower part extends downwards to form an air column for isolation. After venting, the upper part of the silicone rubber sealing skirt 4 detaches from the grid plate 5 and returns to the surface of the support 40, while the lower air column retracts to its original shape and covers the surface of the support 40, allowing liquid to pass through the holes in the grid plate and the silicone rubber sealing skirt into the fatty acid recovery zone. During the resin regeneration stage, this forms a physical separation between the anaerobic reaction zone II and the fatty acid recovery zone III. See also... Figure 4a and Figure 4b As shown.
[0027] Fatty acid recovery zone III: Structurally located at the top of the anaerobic reaction zone, filled with anion exchange resin 7 (model D201) with a height of h=1000 mm. A regenerated liquid injection device is installed 150 mm from the top of fatty acid recovery zone III, including a filling pipe 8 and a variable diameter annular distribution pipe 80 for injecting regenerated liquid. The variable diameter annular distribution pipe 80 has a diameter of 20 mm at the connection with the filling pipe 8, gradually expanding to 30 mm in the middle. Inclined holes with a diameter of 3 mm (downward at 15°) are opened on the pipe surface at 150 mm intervals. A flow regulating valve and a pressure gauge are installed at the inlet of the filling pipe 8.
[0028] In this example, a mixed solution containing 0.5 mol / L NaOH and 1.0 mol / L NaCl was used as the regeneration solution, which can effectively regenerate the resin and promote the desorption of fatty acids.
[0029] The structure of the regenerated liquid injection device in this example is as follows: Figures 5a-5cAs shown, the variable-diameter annular distribution pipe 80 is made of stainless steel, forming a ring. Both ends of the ring's diameter connect to the filling pipe. The stainless steel pipe has a gradually changing diameter, with a smaller diameter at the connection point and gradually expanding towards both ends. The orifice diameter on the variable-diameter annular distribution pipe 80 also varies, from 3mm at the smallest diameter point to one-third of the diameter at both ends, 6mm from one-third to two-thirds of the diameter at both ends, and 9mm from two-thirds of the diameter to the largest diameter point. This variable-diameter annular distribution pipe utilizes diameter variation combined with orifice variation to achieve uniform filling of the regenerated solution. It has a simple structure, requires no additional stirring device, is low in cost, and promotes uniform regenerated solution injection, ensuring the injected regenerated solution is distributed as evenly as possible in fatty acid recovery zone III. It is very suitable for this integrated reaction chamber structure.
[0030] Water outlet zone IV: Located above fatty acid recovery zone III, it is equipped with four stainless steel inverted U-shaped siphon pipes 9, symmetrically distributed at 90° intervals. The water inlet end of the siphon pipe is 50 mm away from the variable diameter distribution pipe, and the water outlet flows into the water outlet pipe 3 with a diameter of 80 mm.
[0031] Gas collecting chamber V: Located at the top of the reaction chamber, it is where gas collecting chamber 12 is located. Gas outlet pipe 10, gas collecting pipe 11 and pressure reducing valve 13 are installed here. The opening and closing pressures of pressure reducing valve 13 are set to 105-110 kPa and 95-100 kPa, respectively.
[0032] The wastewater treatment process of this device is described as follows: Wastewater enters the three-dimensional water distributor through the inlet pipe and rises evenly to the anaerobic reaction zone II. Under the action of anaerobic microorganisms, it comes into contact with granular sludge and undergoes anaerobic hydrolysis and acidification reactions, converting organic matter into volatile fatty acids. The wastewater continues to flow upward, passing through a screen to filter sludge before entering the fatty acid recovery zone III. Anion exchange resin 7 adsorbs fatty acids through ion exchange. After treatment, the wastewater level rises to the apex of siphon pipe 9 (preset height), triggering drainage. When the liquid level touches the inverted U-shaped siphon pipe 9, the siphon effect is activated, and the wastewater flows through four siphon pipes into the outlet pipe 3 for rapid discharge. The pressure reducing valve in the gas collection zone regulates the pressure in real time. When the pressure exceeds 110 kPa, it releases gas to reduce pressure; when it falls below 95 kPa, it closes to maintain system pressure balance. This drainage device, constructed with an inverted U-shaped siphon pipe, works in conjunction with the pressure control system of the gas collection chamber, utilizing the siphon effect for drainage. This reduces the structural complexity of the drainage device and helps save energy.
[0033] During regeneration, the inlet pipe 1 is closed, and the pneumatic drive system is activated. The telescopic sealing skirt 4 extends downwards until it is tightly fitted with the grid plate 5, isolating the anaerobic reaction zone II from the recovery zone III. Then, the inlet valve of the injection pipe 8 is opened, and the regenerant is injected at a flow rate of 1 m / s and a pressure of 101 kPa into a regenerant containing 0.5 mol / L NaOH and 1.0 mol / L NaCl. The liquid is evenly distributed through the variable-diameter annular distribution pipe 80, desorbing the fatty acids adsorbed by the resin. The desorbed liquid passes through the fatty acid absorber above the grid plate 5—the cross-shaped recovery pipe 6 (e.g., Figure 6 (As shown) The recovered fatty acid solution is fed into the main pipe and enters the subsequent purification unit. After regeneration, the sealing skirt shrinks and resets. Gases such as methane (CH4) and carbon dioxide (CO2) produced by the anaerobic reaction are temporarily stored in the gas collection chamber and then transported to the gas processing system through the gas outlet pipe. The pressure reducing valve is linked to the gas collection pipe to prevent the risk of excessive gas pressure and ensure the safe operation of the unit.
[0034] The technical solution of this application incorporates a fatty acid recovery zone within the reaction chamber of an anaerobic biological treatment device, recovering fatty acids during wastewater treatment. This represents an integrated device for wastewater treatment and fatty acid recovery. Due to structural limitations of the integrated device and considering compatibility with the anaerobic biological treatment process, the isolation device is designed for simplicity and ease of operation. Similarly, the regenerated liquid injection device also needs to reduce complexity and improve liquid injection uniformity. The isolation device and regenerated liquid injection device described below can serve as alternative solutions: Example 2
[0035] The structure of the device in this example is the same as that in Example 1, except that the structures of the isolation device and the regenerated liquid filling device are different, which will be described below: In this example, the isolation device consists of two identical circular stainless steel plates 51 and 52, concentrically arranged and each having a 10mm through hole 50. Stainless steel plate 52 is fixed, while stainless steel plate 51 can rotate at a certain angle. During regeneration, closing the inlet pipe 1 and rotating stainless steel plate 51 offsets the through holes 50 of the two plates, thus achieving isolation between the anaerobic reaction zone and the fatty acid recovery zone. Figure 7a As shown. After regeneration, rotating stainless steel plate 51 so that the through holes 50 of the two stainless steel plates overlap allows the anaerobic reaction zone and fatty acid recovery zone to be reopened (connected), as shown. Figure 7b As shown.
[0036] In this example, the regenerated liquid filling device can be composed of several spray nozzles similar to shower heads. These nozzles are connected to the regenerated liquid and are evenly distributed on the fatty acid recovery zone, which can also achieve uniform filling of the regenerated liquid.
[0037] The embodiments described above are merely preferred implementations of this application and are not intended to limit the technical solutions of this application. For example, the dimensions (H, R) of the reaction chamber 100, the anion exchange resin filling height h, and other pipe diameters can be selected according to the specific wastewater treatment volume and are not limited to the dimensions given in the above embodiments. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this application. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.
Claims
1. An integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery, comprising a reaction chamber, a water distributor at the bottom and a gas collection chamber at the top, an anaerobic reaction zone above the water distributor, the anaerobic reaction zone being filled with anaerobic granular sludge, wastewater being evenly distributed through the water distributor and entering the anaerobic reaction zone for treatment, and gas generated during the treatment process being collected in the gas collection chamber; characterized in that, A fatty acid recovery zone is located at the top of the anaerobic reaction zone. An isolation device is installed between the anaerobic reaction zone and the fatty acid recovery zone to control their separation and opening. The fatty acid recovery zone is filled with anion exchange resin and equipped with a regenerant injection device and a fatty acid absorber. The regenerant injection device is used to inject regenerant, and the fatty acid absorber is used to recover fatty acids. The isolation device consists of two identical circular stainless steel plates, which are concentrically arranged and both have through holes. One stainless steel plate is fixed, while the other can rotate at a certain angle. The fatty acid absorber is a cross-shaped recovery tube.
2. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 1, characterized in that, The reaction chamber is cylindrical.
3. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 1, characterized in that, The regenerated liquid injection device includes a variable diameter annular distribution pipe and a filling pipe; the variable diameter annular distribution pipe is used to uniformly distribute the regenerated liquid, and the filling pipe is connected to the variable diameter annular distribution pipe for inputting the regenerated liquid.
4. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 3, characterized in that, The variable diameter annular distribution pipe is a stainless steel pipe, which forms a ring. The two ends of the ring's diameter are connected to the filling pipe. The stainless steel pipe has a gradually changing diameter, with a smaller diameter at the connection point with the filling pipe, gradually expanding towards both ends.
5. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 1, characterized in that, The fatty acid recovery zone is equipped with a drainage device that discharges liquid when the liquid level reaches a set position.
6. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 5, characterized in that, The drainage device consists of an inverted U-shaped siphon tube, which uses the siphon effect to discharge liquid.
7. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 6, characterized in that, The gas collection chamber is equipped with a pressure regulating valve, which is used in conjunction with the inverted U-shaped siphon to control liquid discharge.
8. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 1, characterized in that, The regenerated solution is a mixture of NaOH and NaCl.
9. The integrated device for anaerobic biological treatment of wastewater coupled with fatty acid recovery according to claim 8, characterized in that, The mixture contains 0.5 mol / L NaOH and 1.0 mol / L NaCl.