Sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemical wastewater treatment device

Abstract

The application relates to the technical field of sewage treatment, and particularly discloses a sewage treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupling electrochemistry, which comprises a reaction device, a water storage container, a water inlet pipeline assembly and a backflow pipeline assembly; the reaction device comprises a reactor tank body, a power supply and an electrode cylinder assembly; the power supply is electrically connected with the electrode cylinder assembly; the reactor tank body is sequentially provided with a gap filler layer, a sulfur granule layer and a composite sulfur-sulfur pyrite-PLA ball biological carrier micro-particle layer from bottom to top; the electrode cylinder assembly is vertically fixed above the sulfur granule layer, and the electrode cylinder assembly is located in the composite sulfur-sulfur pyrite-PLA ball biological carrier micro-particle layer; and the top end of the reactor tank body is provided with an overflow groove; the sewage treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupling electrochemistry has simple process, high stability, can quickly supplement the biological carrier, and has high denitrification efficiency and phosphorus removal efficiency for landfill leachate.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a wastewater treatment device based on an autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry. Background Technology

[0002] Landfill leachate has a complex composition and currently lacks a fully mature treatment process, making it one of the most difficult wastewaters to treat. It is characterized by high concentrations of BOD and COD, as well as high levels of heavy metals, ammonia nitrogen, and total phosphorus. Leachate is a secondary pollution source during the landfill process; high concentrations of ammonia nitrogen can have severe toxic effects on water bodies, organisms, and soil. Direct discharge into the environment without treatment will cause serious environmental pollution. Therefore, landfill leachate discharge requires prior treatment through a series of nitrogen and phosphorus removal processes to reduce its environmental toxicity.

[0003] Traditional heterotrophic nitrification-denitrification, short-cut nitrification-denitrification, and novel anaerobic ammonia oxidation processes all suffer from incomplete nitrogen removal and high nitrification content in landfill leachate treatment. Continuing to use heterotrophic denitrification for deep nitrogen removal would require the addition of large amounts of organic carbon sources, increasing operating costs and potentially causing secondary pollution.

[0004] Sulfur autotrophic denitrification is a novel deep nitrogen removal process for wastewater, requiring no additional carbon source, resulting in low carbon emissions and low operating costs. However, in actual operation, this process suffers from problems such as rapid alkalinity consumption, low treatment load, low electron transfer efficiency, and low nitrogen removal efficiency. Furthermore, the development of biomass carrier materials for sulfur autotrophic denitrification also has shortcomings. Currently, the market primarily uses block or clump-shaped pure sulfur carrier materials, which suffer from mutual clogging and entanglement, poor microbial adhesion, difficulty in stable biofilm formation, low treatment efficiency, and inability to simultaneously remove phosphorus. Therefore, improvements are necessary. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry. The device has a simple process, high stability, and can quickly replenish biological carriers, and has high denitrification and phosphorus removal efficiency for landfill leachate.

[0006] To solve the above problems, the present invention adopts the following technical solution:

[0007] A wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry includes a reaction device, a water storage container, an inlet pipeline assembly, and a return pipeline assembly.

[0008] One end of the water inlet pipe assembly is configured to be connected to the reaction device, and the other end of the water inlet pipe assembly is configured to be connected to the water storage container.

[0009] One end of the reflux pipeline assembly is configured to be connected to the reaction device, and the other end of the reflux pipeline assembly is configured to be connected to the water storage container.

[0010] The reaction apparatus includes a reactor tank, a power supply, and an electrode cylinder assembly.

[0011] The power source is electrically connected to the electrode cylinder assembly.

[0012] The reactor tank is configured from bottom to top with a void filler layer, a sulfur particle layer, and a composite sulfur-pyrite-PLA sphere biological carrier microparticle layer.

[0013] The electrode cylinder assembly is vertically fixed above the sulfur particle layer, and the electrode cylinder assembly is located within the composite sulfur-pyrite-PLA sphere biocarrier microparticle layer.

[0014] An overflow trough is provided at the top of the reactor tank.

[0015] The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in at least one embodiment of this disclosure further includes: a stirring device, which is used to stir the liquid in the water storage container.

[0016] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the microparticle layer of the composite sulfur-pyrite-PLA ball biological carrier is filled in the reactor tank with a volume of 70%-90% of the remaining volume above the sulfur particle layer.

[0017] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the composite sulfur-pyrite-PLA ball biological carrier microparticle layer is configured to be filled with composite sulfur-pyrite-PLA ball biological carrier microparticles.

[0018] The composite sulfur-pyrite-PLA sphere biocarrier microparticles have a spherical structure.

[0019] The particle size of the composite sulfur-pyrite-PLA sphere biocarrier microparticles is 8-12 mm.

[0020] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the bottom of the reactor tank is provided with an inlet and the side of the reactor tank is provided with a reflux port.

[0021] The water inlet is configured to be connected to the water inlet pipeline assembly.

[0022] The return port is located below the overflow trough and is configured to be connected to the return pipeline assembly.

[0023] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, both the inlet pipeline assembly and the return pipeline assembly include connecting pipes and pump bodies.

[0024] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the electrode cylinder assembly includes a first titanium mesh cylinder and a second titanium mesh cylinder.

[0025] The first titanium mesh tube is configured to be connected to the negative terminal of the power supply.

[0026] The second titanium mesh tube is configured to be connected to the positive terminal of the power source.

[0027] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the diameter of the first titanium mesh cylinder is larger than the diameter of the second titanium mesh cylinder.

[0028] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the ratio of the diameter of the first titanium mesh cylinder to the diameter of the second titanium mesh cylinder is 2:1.

[0029] In at least one embodiment of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry provided in this disclosure, the porosity of the void filler layer is 40%-50%.

[0030] The beneficial effects of this invention are as follows: by adopting an upflow treatment, the wastewater enters from the bottom, is treated by the packing layer, and then flows out through the overflow trough. The bottom water is evenly dispersed to the upper layer, which makes the effluent more uniform and helps to improve the overall nitrogen and phosphorus removal effect.

[0031] The sulfur particle layer is filled with a composite sulfur-pyrite-PLA sphere biological carrier microparticle layer. The carrier has a large specific surface area, strong biocompatibility, and high porosity, making it easier for microorganisms to attach.

[0032] The process is simple, highly stable, and can be quickly replenished with biological carriers. It has high efficiency in denitrification and phosphorus removal from landfill leachate. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0034] Figure 1The structural block diagram of the wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry is shown in Figure 1.

[0035] Figure 2 This is a structural block diagram of the reaction apparatus.

[0036] Figure 3 for Figure 2 Enlarged view of point A.

[0037] Figure 4 The structural block diagram of two wastewater treatment devices based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry is shown.

[0038] Figure 5 The NO2 in the influent and effluent of the experimental and control groups in Experiment Example 1. - -N concentration trend graph.

[0039] Figure 6 For the influent and effluent NO2 in the experimental group of Experiment Example 2 - -N concentration change trend.

[0040] In the picture:

[0041] 10. Reaction apparatus; 11. Reactor tank; 12. Power supply; 13. Electrode cylinder assembly; 14. Overflow tank; 111. Void packing layer; 112. Sulfur particle layer; 113. Composite sulfur-pyrite-PLA sphere biological carrier microparticle layer; 131. First titanium mesh cylinder; 132. Second titanium mesh cylinder;

[0042] 20. Water storage container;

[0043] 30. Water inlet pipe assembly;

[0044] 40. Return piping assembly;

[0045] 50. Stirring device. Detailed Implementation

[0046] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments, not all embodiments.

[0047] Example 1

[0048] like Figures 1 to 3 As shown, a wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry includes a reaction device 10, a water storage container 20, an inlet pipeline assembly 30, and a return pipeline assembly 40.

[0049] Furthermore, one end of the water inlet pipe assembly 30 is configured to be connected to the reaction device 10, and the other end of the water inlet pipe assembly 30 is configured to be connected to the water storage container 20.

[0050] Furthermore, one end of the reflux pipeline assembly 40 is configured to be connected to the reaction device 10, and the other end of the reflux pipeline assembly 40 is configured to be connected to the water storage container 20.

[0051] Furthermore, the reaction apparatus 10 includes a reactor tank 11, a power supply 12, and an electrode cylinder assembly 13.

[0052] Specifically, the power supply 12 is electrically connected to the electrode cylinder assembly 13. The reactor tank 11 is provided with a void packing layer 111, a sulfur particle layer 112, and a composite sulfur-pyrite-PLA ball biological carrier microparticle layer 113 from bottom to top.

[0053] Specifically, the electrode cylinder assembly 13 is vertically fixed above the sulfur particle layer 112, and the electrode cylinder assembly 13 is located within the composite sulfur-pyrite-PLA sphere biological carrier microparticle layer 113.

[0054] Specifically, an overflow trough 14 is provided at the top of the reactor tank 11. Wastewater enters from the bottom, is treated by the reaction device 10, and then flows out through the overflow trough 14.

[0055] In this embodiment, the composite sulfur-pyrite-PLA sphere biocarrier microparticle layer 113 fills the reactor tank 11 with a volume of 70%-90% of the remaining volume above the sulfur particle layer 112.

[0056] Preferably, the composite sulfur-pyrite-PLA sphere biocarrier microparticle layer 113 fills 80% of the remaining volume above the sulfur particle layer 112 in the reactor tank 11.

[0057] In this embodiment, the composite sulfur-pyrite-PLA sphere biological carrier microparticle layer 113 is configured to be filled with composite sulfur-pyrite-PLA sphere biological carrier microparticles. The composite sulfur-pyrite-PLA sphere biological carrier microparticles fill the gap between the electrode cylinder assembly and the reactor tank 11.

[0058] Specifically, the composite sulfur-pyrite-PLA sphere biocarrier microparticles have a spherical structure.

[0059] Specifically, the composite sulfur-pyrite-PLA sphere biocarrier microparticles have a particle size of 8-12 mm and a porosity of 50%.

[0060] Preferably, the particle size of the composite sulfur-pyrite-PLA sphere biocarrier microparticles is 10 mm.

[0061] For example, the preparation steps of the composite sulfur-pyrite-PLA sphere biocarrier microparticles are as follows:

[0062] 1. The sulfur and pyrite solids are crushed in a high-speed crusher (XY-4500b) and passed through a 100-mesh sieve. The sieved mixed powder is then mixed with quicklime powder and sodium bicarbonate and stirred evenly to make powder. The mass ratio of sulfur, pyrite, quicklime and sodium bicarbonate is 1:3:0.2:0.1.

[0063] 2. Slowly add a 0.2% PAM aqueous solution to the powder in step 1), with the mass of the solution being 1 / 3 of the powder mass. Then add PLA (polylactic acid) particles (0.5-1mm in diameter) with a mass of 1 / 4 of the powder mass, and stir evenly to obtain a paste with a water content of 25% (w / w).

[0064] 3) First, evenly add the powder from step 1) into the round pot granulator. Then, add the paste from step 2) into the round pot granulator. The mass ratio of powder to paste is 1:1. The round pot granulator rotates the mixture into balls at a speed of 60 r / min. The material gradually forms a carrier core. Continue to add the powder from step 1) into the pot until the mass ratio of powder to paste is 2:1. The core gradually increases until the desired finished particle size is reached. Then, adjust the speed to 30 r / min and turn on the drying fan to dry and shape at 65℃ to obtain composite sulfur-pyrite-PLA sphere biological carrier microparticles.

[0065] In the denitrification and phosphorus removal process, sulfur, PLA (polylactic acid), and pyrite serve as the main materials of the biological carrier. Sulfur (reduced elemental sulfur) provides electron donors for deep denitrification; sulfides in pyrite act as electron donors for denitrification, and iron ions act as an exogenous electron medium to enhance sulfur autotrophic denitrification. Iron ions also have a highly efficient phosphorus removal effect. Quicklime powder provides alkalinity during the slow consumption of the carrier, maintaining pH stability in the reaction system. Sodium bicarbonate is added during carrier preparation at 60℃. The decomposition produces gas, creating a porous structure inside the carrier, which is more conducive to microbial attachment. PLA (polylactic acid) is a biodegradable plastic that can be gradually decomposed by microorganisms in water, thereby increasing the specific surface area of ​​the autotrophic denitrification and phosphorus removal composite biological carrier. PAM gives the carrier material biocompatibility, allowing it to be fully hydrolyzed after sulfur, pyrite, and quicklime are completely consumed in the carrier without causing pipe blockage. When the carrier material is consumed during operation, simply replenishing the carrier material to the original filling height will restore the denitrification effect without the need for additional operations such as mixing.

[0066] In this embodiment, the bottom of the reactor tank 11 is provided with a water inlet 114, and the side of the reactor tank 11 is provided with a return port 115.

[0067] Specifically, the water inlet pipeline assembly 30 is connected to the reactor tank 11 via the water inlet 114.

[0068] Specifically, the reflux port 115 is located below the overflow tank 14, and the reflux pipeline assembly 40 is connected to the reactor tank 11 through the reflux port 115.

[0069] For example, both the inlet piping assembly 30 and the return piping assembly 40 include connecting pipes (not shown) and a pump body (not shown).

[0070] In this embodiment, the electrode cylinder assembly 13 includes a first titanium mesh cylinder 131 and a second titanium mesh cylinder 132. The first titanium mesh cylinder 131 is configured to be connected to the negative terminal of the power supply 12. The second titanium mesh cylinder 132 is configured to be connected to the positive terminal of the power supply 12, and the first titanium mesh cylinder 131 and the second titanium mesh cylinder 132 adopt a concentric sleeve structure.

[0071] Furthermore, the diameter of the first titanium mesh cylinder 131 is larger than the diameter of the second titanium mesh cylinder 132.

[0072] Preferably, the ratio of the diameter of the first titanium mesh cylinder 131 to the diameter of the second titanium mesh cylinder 132 is 2:1.

[0073] Specifically, the diameters of the first titanium mesh tube 131 and the second titanium mesh tube 132 are 12cm and 6cm, respectively.

[0074] In this embodiment, the void packing layer 111 is a uniformly distributed porous void packing with a porosity of 40%-50%, which makes the water entering from the bottom of the reactor evenly dispersed to the upper layer, resulting in more uniform effluent and improving the overall nitrogen and phosphorus removal effect.

[0075] Example 2

[0076] like Figure 4 As shown, this embodiment discloses a wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry, which is largely the same as that in Embodiment 1, except that it also includes a stirring device 50, which is used to stir the liquid in the water storage container 20.

[0077] Experimental Example 1

[0078] The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry disclosed in Example 2 was used as the experimental group to treat the leachate from a landfill, and a control group with a traditional packing device was set up.

[0079] The process conditions for both the experimental and control groups were as follows: the effective volume of the reactor tank was 8.6L, the influent flow rate Q was 17.2L / d, the hydraulic retention time was 12h, the influent pH was 8.0±0.3, the reaction temperature was 30±1℃, and the reflux flow rate was set to 3Q, which was refluxed into the water storage container, mixed and stirred, and then reintroduced into the reactor body through the inlet; the reactor tank was equipped with, from bottom to top, a void filler layer, a sulfur particle layer, and a composite sulfur-pyrite-PLA ball biological carrier microparticle layer; the composite sulfur-pyrite-PLA ball biological carrier microparticle layer was filled with composite sulfur-pyrite-PLA ball biological carrier microparticles.

[0080] The only difference between the control group and the experimental group was that the external power supply voltage of the experimental group was 2V, the resistance was 50Ω, and the system current was 20mA; the control group did not have an external power supply.

[0081] The process operation methods for the two sets of units are as follows:

[0082] The first phase is the start-up phase, which lasts for 10 days. The influent is landfill leachate diluted three times, containing NO2. - The -N concentration was 300±50 mg / L, and neither the experimental group nor the control group had an external power source.

[0083] The second phase is the enhancement phase, which lasts for 10 days. The influent is leachate diluted twice, containing NO2. - The -N concentration was 600±50mg / L. The experimental group was powered by an external power source with a voltage of 1V and a current of 10mA, while the control group was not powered by an external power source.

[0084] The third stage is the stabilization stage, which lasts for 50 days. The influent is undiluted landfill leachate, containing NO2. - The -N concentration was 900±50mg / L. The experimental group was powered by an external power supply with a voltage of 2V and a current of 20mA, while the control group was not powered by an external power supply.

[0085] By monitoring the NO2 in the effluent at each stage - -N concentration, representing the NO2 concentration in the reaction apparatus. - -N removal efficiency changes.

[0086] Figure 5 NO2 in the influent and effluent of the experimental and control groups - The graph shows the trend of NO2 concentration changes in landfill leachate. It illustrates how the experimental group, under enhanced external power supply, reduced the concentration of NO2 in the leachate. - -N has a better removal effect, reaching over 98%.

[0087] Experiment Example 2

[0088] The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry disclosed in Example 1 was used as the experimental group to treat wastewater from a pig farm.

[0089] The experimental group used wastewater from a pig farm that had undergone short-cut nitrification as the influent. The effective volume of the reactor tank was 15L, the influent flow rate Q was 60L / d, the hydraulic retention time was 6h, and the influent NO2 content was [not specified]. - The NO concentration was 300±50 mg / L; the reflux flow rate was set to 4Q, and the reflux was returned to the storage container, mixed, and then reintroduced into the reactor tank through the inlet. The reactor tank contained, from bottom to top, a porous filler layer, a sulfur granule layer, and a composite sulfur-pyrite-PLA sphere biological carrier microparticle layer. The composite sulfur-pyrite-PLA sphere biological carrier microparticle layer was filled with these microparticles. The influent pH was 8.5±0.3, the reaction temperature was 30±1℃, the external power supply voltage was 1V, the resistance was 50Ω, and the system current was 10mA. The reaction time was 70 days, and the inoculated sludge was the high-concentration NO2 resistant sludge from Experiment 1. - -N sulfur autotrophic denitrification sludge with a sludge concentration of 10 g MLSS / L.

[0090] By monitoring the daily NO2 in the effluent - -N concentration, representing NO2 concentration in the experimental group - -N removal efficiency changes.

[0091] Figure 6 The influent and effluent NO2 of the experimental group - The trend of NO2- concentration change is shown in the figure. As can be seen from the figure, the experimental group not only affected NO2- concentration in landfill leachate... - -N has a good removal effect, and it is also effective in removing NO2 from the wastewater of this pig farm. - -N also has a high removal rate, reaching over 95%.

[0092] Although embodiments of this application have been shown and described above, the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be conceived without inventive effort should be covered within the scope of protection of this invention. Unless expressly stated otherwise, no element, action or instruction used herein should be construed as critical or necessary.

Claims

1. A wastewater treatment device based on a sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry, characterized in that, include: Reaction apparatus; Water storage container; A water inlet pipeline assembly, one end of which is configured to be connected to the reaction device, and the other end of which is configured to be connected to the water storage container; and A reflux pipeline assembly, one end of which is configured to be connected to the reaction device, and the other end of which is configured to be connected to the water storage container; The reaction apparatus includes a reactor tank, a power supply, and an electrode cylinder assembly. The power supply is electrically connected to the electrode cylinder assembly; The reactor tank is configured from bottom to top with a void filler layer, a sulfur particle layer, and a composite sulfur-pyrite-PLA sphere biological carrier microparticle layer. The electrode cylinder assembly is vertically fixed above the sulfur particle layer, and the electrode cylinder assembly is located within the composite sulfur-pyrite-PLA sphere biocarrier microparticle layer. An overflow trough is provided at the top of the reactor tank; The reactor tank is equipped with a water inlet at the bottom and a reflux port on the side of the reactor tank; The water inlet is configured to be connected to the water inlet pipeline assembly; The return port is located below the overflow trough, and the return port is configured to be connected to the return pipeline assembly; The composite sulfur-pyrite-PLA sphere biocarrier microparticle layer fills 70%-90% of the remaining volume above the sulfur particle layer in the reactor tank. The composite sulfur-pyrite-PLA sphere biological carrier microparticle layer is configured to be filled with composite sulfur-pyrite-PLA sphere biological carrier microparticles. The composite sulfur-pyrite-PLA sphere biological carrier microparticles fill the gap between the electrode cylinder assembly and the reactor tank. The composite sulfur-pyrite-PLA spherical biological carrier microparticles have a spherical structure. The particle size of the composite sulfur-pyrite-PLA sphere biocarrier microparticles is 8-12 mm. The electrode cylinder assembly includes a first titanium mesh cylinder and a second titanium mesh cylinder; The first titanium mesh tube is configured to be connected to the negative terminal of the power supply; The second titanium mesh tube is configured to be connected to the positive terminal of the power supply; The first titanium mesh cylinder and the second titanium mesh cylinder adopt a concentric sleeve structure; The diameter of the first titanium mesh tube is larger than the diameter of the second titanium mesh tube.

2. The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry according to claim 1, characterized in that, Also includes: A stirring device used to stir the liquid in a water storage container.

3. The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry according to claim 1, characterized in that, Both the inlet pipe assembly and the return pipe assembly include connecting pipes and a pump body.

4. The wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry according to claim 1, characterized in that, The ratio of the diameter of the first titanium mesh tube to the diameter of the second titanium mesh tube is 2:

1.

5. A wastewater treatment device based on sulfur autotrophic denitrification and phosphorus removal biological carrier coupled with electrochemistry according to claim 1, characterized in that, The porosity of the void filler layer is 40%-50%.

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