Biochemical reactor system and method for domestic waste leachate

Abstract

The invention provides a biochemical reactor system and method for household garbage leachate, and the biochemical reactor system for the household garbage leachate comprises an integrated reactor which is internally provided with a DIET anaerobic reaction zone used for degrading organic matters in the household garbage leachate; and the anaerobic ammonia oxidation reaction zone is used for carrying out denitrification treatment on the domestic waste leachate. According to the technical scheme, the removal efficiency of organic pollutants and total nitrogen in the leachate treatment process is improved, the methane production efficiency is improved, the energy consumption is reduced, and the carbon emission is reduced.

Description

Background Art

[0002] The common process of the leachate treatment system in current domestic waste incineration plants is to homogenize through an adjustment tank, remove organic pollutants by an anaerobic system, remove nitrogen-containing pollutants by an MRB biofilm system, then remove salts through a membrane system, and finally produce about 60% - 75% of recycled water and 25% - 40% of membrane concentrate.

[0003] In this common process, the main biochemical processes for removing organic pollutants (COD, BOD) and total nitrogen (ammonia nitrogen, nitrate nitrogen, organic nitrogen, etc.) are the biochemical combination of an anaerobic system (common reactors such as UASB, UBF, EGSB, etc.) and a two-stage nitrification and denitrification tank (A / O). In the anaerobic reactor, organic pollutants undergo four stages of hydrolysis, acidification, acetification, and methanogenesis under the metabolic action of microorganisms, and are finally converted into methane and carbon dioxide; in the nitrification and denitrification tank, ammonia nitrogen is converted into nitrate nitrogen by nitrifying bacteria, and nitrate nitrogen is then converted into nitrogen gas by denitrifying bacteria. The above two biochemical processes can remove most of the organic pollutants and total nitrogen in the water body. However, there are some problems and deficiencies in this common biochemical process.

[0004] Limitations of the UASB anaerobic process:

[0005] It relies on hydrogen / formate-mediated interspecies hydrogen transfer (IHT), with low electron transfer efficiency, resulting in slow organic matter degradation rate and long methanogenesis period.

[0006] The theoretical value of anaerobic methane production rate is 0.35m 3 / kgCOD, while general anaerobic reactions can only reach 40 - 80%;

[0007] The problem of carbon-nitrogen ratio (C / N) imbalance is prominent and cannot meet the subsequent denitrification requirements. When the carbon-nitrogen ratio is too low, additional carbon sources (such as methanol, glucose) need to be added, increasing the operating cost.

[0008] Poor shock load resistance, and fluctuations in leachate quality are likely to cause sludge loss and reactor acidification.

[0009] The commonly used UASB reactor has a short-circuit problem and also requires an independent sludge tank and sedimentation tank; the three-phase separation effect of the UBF reactor is poor, the film hanging effect is unstable, and the water distribution is uneven; the EGSB reactor has high energy consumption and a complex structure.

[0010] Defects of the OA process:

[0011] The aerobic section requires a large amount of aeration, with high energy consumption (accounting for more than 60% of the total system energy consumption), and a large amount of excess sludge is generated (0.3 - 0.5 kg of sludge / kg COD).

[0012] During the denitrification stage, a carbon source needs to be added, resulting in high chemical costs (the water treatment cost per ton increases by 2 - 3 yuan), and there is also a risk of secondary pollution.

[0013] The oxidation efficiency of ammonia is significantly affected by temperature (the optimal temperature is 30 - 35°C), and the nitrogen removal efficiency decreases by 30% - 50% in a low-temperature environment.

[0014] The volume of the tank body is large, occupying a large area and having a high investment.

[0015] Disadvantages of traditional biochemical process combinations:

[0016] The anaerobic and aerobic units are separately installed, occupying a large area and having complex pipelines;

[0017] The intermediate transition link is prone to causing carbon source waste and the escape of greenhouse gases (CH4, N2O). Summary of the Invention

[0018] The present application provides a biochemical reactor system and method for domestic waste leachate, aiming to improve the biogas production efficiency, reduce energy consumption, and reduce carbon emissions.

[0019] In a first aspect, a biochemical reactor system for domestic waste leachate is provided, including: an integrated reactor, wherein,

[0020] The following are arranged inside the integrated reactor:

[0021] A DIET anaerobic reaction zone for degrading organic matters in domestic waste leachate;

[0022] An anaerobic ammonium oxidation reaction zone for denitrifying the domestic waste leachate.

[0023] In the above technical solution, by setting an integrated reactor, the following are arranged inside the integrated reactor: a DIET anaerobic reaction zone for degrading organic matters in domestic waste leachate; an anaerobic ammonium oxidation reaction zone for denitrifying the domestic waste leachate; the removal efficiency of organic pollutants and total nitrogen in the leachate treatment process is improved, the biogas production efficiency is improved, the energy consumption is reduced, the carbon emissions are reduced, and the volume of the tank body is reduced, thereby reducing the land occupation scale and investment and operation costs.

[0024] In a specific and feasible implementation scheme, the following are arranged in the DIET anaerobic reaction zone:

[0025] Activated carbon mesh bags for forming an electron transfer network.

[0026] In a specific and feasible implementation scheme, the particle size of the activated carbon is 1 - 3 mm.

[0027] In a specific and feasible implementation scheme, the activated carbon mesh bags are arranged in layers, and the distance between the activated carbon mesh bag layers is not less than 0.3 m.

[0028] Specifically,

[0029] In a specific feasible embodiment, the DIET anaerobic reaction zone and the anammox reaction zone are arranged in a front-back coupling manner.

[0030] In a specific feasible embodiment, the anammox reaction zone is provided with a honeycomb polyethylene packing box.

[0031] In a specific feasible embodiment, a sodium alginate-bentonite composite gel layer is provided on the inner wall of the honeycomb polyethylene packing box.

[0032] In a specific feasible embodiment, the anammox reaction zone is provided with a microporous aeration system.

[0033] In a specific feasible embodiment, the activated carbon mesh bag is made of stainless steel.

[0034] Second, a biochemical reaction method for domestic waste leachate is provided, including the following steps:

[0035] Degrading the organic matter in the domestic waste leachate by using the DIET anaerobic reaction zone;

[0036] Performing denitrification treatment on the domestic waste leachate by using the anammox reaction zone.

[0037] In the above technical solution, by setting an integrated reactor, the integrated reactor is provided with: a DIET anaerobic reaction zone for degrading the organic matter in the domestic waste leachate; an anammox reaction zone for performing denitrification treatment on the domestic waste leachate; improving the removal efficiency of organic pollutants and total nitrogen in the leachate treatment process, improving the biogas production efficiency, reducing energy consumption, reducing carbon emissions, reducing the tank volume, thereby reducing the land occupation scale and investment and operation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural block diagram of a biochemical reactor system for domestic waste leachate provided by an embodiment of the present application;

[0039] Figure 2 It is a flow block diagram of a biochemical reaction method for domestic waste leachate provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present application will be further described in detail below with reference to the drawings and embodiments. Through these descriptions, the features and advantages of the present application will become more clearly defined.

[0041] As used herein, the term "exemplary" means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" herein need not be construed as superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0042] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0043] To facilitate the understanding of the biochemical reactor system and method for domestic waste leachate provided by the embodiments of the present application, the application scenario thereof will be described first. The biochemical reactor system and method for domestic waste leachate provided by the embodiments of the present application are used to improve the biogas production efficiency, reduce energy consumption, and reduce carbon emissions. The common process of the current domestic waste incineration plant leachate treatment system is to homogenize through an adjustment tank, remove organic pollutants through an anaerobic system, remove nitrogen-containing pollutants through an MRB biofilm system, then remove salts through a membrane system, and finally produce about 60% - 75% of recycled water and 25% - 40% of membrane concentrate. In this common process, the main biochemical processes for removing organic pollutants (COD, BOD) and total nitrogen (ammonia nitrogen, nitrate nitrogen, organic nitrogen, etc.) are the biochemical combination of an anaerobic system (common reactors such as UASB, UBF, EGSB, etc.) and a two-stage nitrification and denitrification tank (A / O). In the anaerobic reactor, organic pollutants undergo four stages of hydrolysis, acidification, acetification, and methanogenesis under the metabolic action of microorganisms, and are finally converted into methane and carbon dioxide; in the nitrification and denitrification tank, ammonia nitrogen is converted into nitrate nitrogen by nitrifying bacteria, and nitrate nitrogen is then converted into nitrogen gas by denitrifying bacteria. The above two biochemical processes can remove most of the organic pollutants and total nitrogen in the water. However, there are some problems and deficiencies in this common biochemical process. Therefore, the embodiments of the present application provide a biochemical reactor system and method for domestic waste leachate to improve the biogas production efficiency, reduce energy consumption, and reduce carbon emissions. The following will be described in detail with specific drawings by way of examples.

[0044] Reference Figure 1 and Figure 2 , Figure 1 is the structural block diagram of the biochemical reactor system for domestic waste leachate provided by the embodiments of the present application; Figure 2 is the flow block diagram of the biochemical reaction method for domestic waste leachate provided by the embodiments of the present application.

[0045] In Figure 1 , the embodiments of the present application provide a biochemical reactor system for domestic waste leachate, including: an integrated reactor, wherein,

[0046] The integrated reactor is provided with:

[0047] DIET anaerobic reaction zone, used for degrading organic matters in domestic waste leachate;

[0048] Anaerobic ammonium oxidation reaction zone, used for denitrifying the domestic waste leachate.

[0049] In the above technical solution, by setting an integrated reactor, the integrated reactor is provided with: a DIET anaerobic reaction zone, used for degrading organic matters in domestic waste leachate; an anaerobic ammonium oxidation reaction zone, used for denitrifying the domestic waste leachate; the removal efficiency of organic pollutants and total nitrogen in the leachate treatment process is improved, the biogas production efficiency is improved, the energy consumption is reduced, the carbon emission is reduced, and the volume of the pool is reduced, thereby reducing the land occupation scale and investment and operation costs.

[0050] Specifically, the beneficial effects of the biochemical reactor system of the domestic waste leachate include:

[0051] 1. The removal efficiency of organic matters and total nitrogen is significantly improved

[0052] Degradation of organic matters:

[0053] The removal rate of COD (chemical oxygen demand) in the DIET reaction zone reaches more than 95%, which is 10-15 percentage points higher than that of traditional anaerobic digestion (removal rate 80-85%).

[0054] Removal of total nitrogen:

[0055] The anaerobic ammonium oxidation reaction zone only requires 50% of the energy consumption to achieve the same total nitrogen (TN) removal rate as the traditional nitrification-denitrification process, and no external carbon source (such as methanol) is required, reducing the operation cost.

[0056] 2. Biogas production efficiency and resource utilization

[0057] Biogas production:

[0058] The DIET reaction zone accelerates the decomposition of organic matters through direct electron transfer, and the biogas production efficiency is increased by 30% (the biogas production per unit COD increases from 0.35 m 3 / kg to 0.45 m 3 / kg), and the methane content in the biogas reaches 65-70%, which can be directly used for power generation or heating.

[0059] Sludge reduction:

[0060] The sludge yield of the anaerobic ammonium oxidation process is only 0.1-0.2 kg VSS / kg TN, which is 60% lower than that of the traditional denitrification process (0.3-0.5 kg VSS / kg TN), reducing the sludge treatment cost.

[0061] 3. Reduction of energy consumption and carbon emission

[0062] Aeration energy consumption:

[0063] The anaerobic ammonium oxidation process does not require aeration, saving about 40% of the electricity cost compared with the traditional nitrification-denitrification process (aeration energy consumption accounts for 50-60% of the total energy consumption).

[0064] Carbon emissions:

[0065] The overall carbon emissions of the system are reduced by 60-70% (including the emission reduction effect of using biogas to replace fossil energy), meeting the "dual carbon" goal.

[0066] 4. Optimization of tank volume and cost

[0067] Tank volume:

[0068] Through functional zoning and efficient reaction, the tank volume of the integrated reactor is reduced by 40-50% compared with the traditional process (separate anaerobic digestion tank, nitrification tank, and denitrification tank), the land occupation scale is reduced, and the investment cost is reduced by 30%.

[0069] Operating cost:

[0070] Combining chemical reagent cost, electricity cost, labor cost, etc., the cost per ton of water treatment is reduced from 15-20 yuan to 8-12 yuan, with significant economic benefits.

[0071] In a specific feasible implementation, the DIET anaerobic reaction zone is provided with:

[0072] Activated carbon mesh bags, used to form an electron transfer network.

[0073] Specifically, the action mechanism of the activated carbon mesh bags includes:

[0074] Conductive network construction:

[0075] Activated carbon has a high specific surface area (>1000m 2 / g) and excellent electrical conductivity (electrical conductivity 10 -2 -10S / m), forming a three-dimensional conductive skeleton through the mesh bag structure to promote direct interspecies electron transfer (DIET) between microorganisms.

[0076] It can be analogized as a "microbial highway", accelerating the transfer of electrons from electrogenic bacteria (such as Geobacter) to methanogenic bacteria (such as Methanosaeta).

[0077] Microbial attachment carrier:

[0078] The surface of the activated carbon is rough and negatively charged (ζ potential about -30mV), which is easy to adsorb positively charged microorganisms (such as through electrostatic interaction), forming a high-density biofilm (biomass reaches 15-20g VSS / L) and improving the reaction rate.

[0079] DIET Process Intensification

[0080] Traditional anaerobic digestion relies on hydrogen as an electron carrier (IHT), but the hydrogen diffusion rate is slow (diffusion coefficient is about 10 - 5 cm 2 / s), which easily leads to acid accumulation.

[0081] DIET achieves "instantaneous electron transfer" (rate increased by 10 3 times) through an activated carbon mesh bag, avoiding hydrogen accumulation, and the system pH is more stable (fluctuation range <0.3).

[0082] Its beneficial effects include:

[0083] 1. Improvement in the degradation efficiency of organic matter

[0084] After setting the activated carbon mesh bag, the COD removal rate increased from 82% to 95%, the reaction rate constant (k) increased from 0.12 d-1 to 0.35 d-1, and the hydraulic retention time (HRT) was shortened by 30 - 40%.

[0085] The DIET pathway bypasses the hydrogen generation step, reducing energy loss (theoretical calculations show that DIET saves 15 - 20% more energy than IHT).

[0086] 2. Improvement in biogas production efficiency and methane purity

[0087] Biogas production: The biogas production per unit COD increased from 0.32 m 3 / kg to 0.48 m 3 / kg, an increase of 50%. This is mainly because DIET reduces the accumulation of intermediate products (such as acetic acid), promoting the direct utilization of electrons by methanogens.

[0088] Methane purity: The methane content in biogas increased from 60% to 68 - 72% because DIET inhibits the competition of hydrogen-producing acetogenic bacteria and optimizes the metabolic pathway of methanogens.

[0089] 3. Enhancement of system stability

[0090] Shock load resistance: Under the condition of ±30% fluctuation in influent COD, the reactor with the activated carbon mesh bag can still maintain a COD removal rate of over 90%, while the removal rate of the traditional reactor drops to 70 - 75%.

[0091] Reduction of acidification risk: The activated carbon mesh bag quickly consumes electron acceptors (such as CO2) through DIET, avoiding the accumulation of volatile fatty acids (VFA), and the system pH is always maintained at 6.8 - 7.5 without the need for additional alkali addition.

[0092] 4. Cost and resource utilization benefits

[0093] Activated carbon lifespan and cost: The net bag structure can slow down the abrasion of activated carbon (lifespan > 3 years), and the proportion of activated carbon in the unit treatment cost is < 5%, which is much lower than the cost of frequently replacing fillers in traditional processes.

[0094] Biogas resource utilization: Biogas with a high methane content can be directly used for power generation (1 m 3 of biogas can generate 1.8 - 2.2 kWh of electricity), or purified into biomethane (CNG), with significant economic benefits.

[0095] In a specific feasible implementation, the particle size of the activated carbon is 1 - 3 mm.

[0096] Specifically, in a specific feasible implementation, the particle size of the activated carbon is set to 1 - 3 mm, and its technical logic and beneficial effects are as follows:

[0097] I. Technical logic and basis for particle size selection

[0098] Microbial attachment and electron transfer efficiency

[0099] Specific surface area and pore structure: Activated carbon particles with a size of 1 - 3 mm have both a high specific surface area (about 800 - 1200 m 2 / g) and an appropriate porosity (0.4 - 0.6 cm 3 / g), which can not only provide sufficient microbial attachment sites but also avoid pore blockage caused by too small particles (e.g., particles < 1 mm are easily blocked by sludge or suspended solids).

[0100] Optimization of electron transfer path: Within this particle size range, the conductive network density and fluid resistance of the activated carbon reach an equilibrium:

[0101] The particle spacing is moderate (about 0.5 - 1 mm), and electrons can be transferred through direct contact or weak electric field coupling, reducing the path loss.

[0102] Avoid the "electron island" phenomenon (insufficient contact between particles) caused by large particles (> 3 mm) or the agglomeration problem of small particles (< 1 mm).

[0103] Hydraulic characteristics and reaction kinetics

[0104] Hydrodynamics advantages: The sedimentation velocity of 1 - 3 mm particles is about 5 - 15 cm / s, which can not only ensure uniform distribution in the reactor but also achieve sufficient mixing of sludge and activated carbon through moderate stirring (50 - 100 rpm), avoiding short - circuit flow or dead zones.

[0105] Mass transfer efficiency: At this particle size, the diffusion resistance of substrates (such as organic matter, electron acceptors) to the surface of activated carbon is small, and the diffusion coefficient (D) is about 10 -6 cm 2 / s, the finer particles (<1 mm) are increased by 20 - 30%, accelerating the reaction rate.

[0106] Beneficial effects include:

[0107] 1. Microbial attachment and biofilm stability

[0108] The biofilm amount on 1 - 3 mm activated carbon particles reaches 18 - 22 g VSS / L, which is 40% higher than that on 0.5 - 1 mm particles (12 - 15 g VSS / L), and the biofilm thickness is more uniform (200 - 300 μm vs. 100 - 150 μm).

[0109] The surface roughness of the particles is moderate (Ra ≈ 1 - 2 μm), which not only provides sufficient mechanical anchoring sites but also avoids excessive roughness leading to biofilm detachment.

[0110] 2. Improvement in DIET (direct interspecies electron transfer) efficiency

[0111] Electron transfer rate: The electron transfer resistance (Ret) of 1 - 3 mm particles is about 50 - 80 Ω, which is 30 - 50% lower than that of finer particles (Ret > 100 Ω), promoting the synergistic metabolism of electrogenic bacteria (such as Geobacter) and methanogenic bacteria (such as Methanosaeta).

[0112] Methane production rate: The methane production rate per unit mass of activated carbon reaches 0.15 - 0.2 L CH4 / (g·d), which is more than 50% higher than that of coarser particles (>3 mm, 0.08 - 0.12 L CH4 / (g·d)).

[0113] 3. Anti - clogging and long - term operation stability

[0114] Clogging risk: The pore connectivity of 1 - 3 mm particles is better than that of finer particles. After 180 days of continuous operation in the experiment, the internal pore clogging rate of the particles is <10%, while the clogging rate of <1 mm particles reaches 30 - 40%.

[0115] Backwashing requirement: At this particle size, the activated carbon bed can restore the flux through low - pressure gas - water combined backwashing (pressure 0.1 - 0.2 MPa), and the backwashing period is extended to 30 - 60 days, reducing the operation and maintenance cost compared with finer particles (which need to be backwashed weekly).

[0116] 4. Cost and resource utilization benefits

[0117] Activated carbon consumption: The packing density of 1 - 3 mm particles is about 0.4 - 0.5 g / cm 3 , and 150 - 200 kg / m of activated carbon is required per unit reactor volume 3 , which is less than that of finer particles (300 - 400 kg / m 3)Reduce by more than 50% and lower the material cost.

[0118] Biogas recovery increment: Due to the improved DIET efficiency, the biogas production increases by 15 - 20%. Calculated based on 0.3 - 0.4 m³ of biogas produced per ton of leachate treated, treating 100,000 tons of leachate annually can produce 45,000 - 80,000 m³ more biogas 3 Calculated based on 0.3 - 0.4 m³ of biogas produced per ton of leachate treated, treating 100,000 tons of leachate annually can produce 45,000 - 80,000 m³ more biogas 3 , with significant economic value.

[0119] In a specific feasible embodiment, the activated carbon mesh bags are arranged in layers, and the distance between the activated carbon mesh bag layers is not less than 0.3 m.

[0120] Specifically, the technical logic and spacing design basis include:

[0121] Fluid mixing and mass transfer requirements

[0122] Fluid mechanics optimization:

[0123] A spacing of 0.3 m can ensure an appropriate fluid turbulence intensity in the reactor (Reynolds number Re ≈ 5000 - 10000), avoiding fluid short - circuiting or laminar flow caused by too small a layer spacing (such as < 0.2 m), thus affecting the diffusion efficiency of substrates (such as organic matter, electron acceptors) to the activated carbon surface.

[0124] Mixing uniformity:

[0125] At this spacing, the shear force generated by the agitator (such as paddle diameter 0.5 m, rotation speed 100 rpm) can cover adjacent mesh bag layers, ensuring sufficient contact between sludge and activated carbon, and increasing the substrate utilization rate by 20 - 30%.

[0126] Microbial metabolism and product diffusion

[0127] Metabolic product removal: Products (such as CO2, CH4) generated by microbial metabolism on the surface of the activated carbon mesh bags need to be diffused to the main fluid in a timely manner. A 0.3 m spacing can ensure unobstructed gas diffusion paths, avoiding local accumulation leading to pH fluctuations or inhibition of microbial activity.

[0128] Continuity of the electron transfer network: Too small a spacing (such as < 0.2 m) may cause the overlap of electron transfer paths between adjacent mesh bag layers, triggering the "electron competition" phenomenon and reducing the DIET (direct interspecies electron transfer) efficiency; a 0.3 m spacing can maintain the independence of the electron transfer network for each layer.

[0129] Engineering implementation and maintenance convenience

[0130] Mesh bag installation and replacement: A 0.3 m spacing provides operating space for the hoisting, fixing, and subsequent replacement of the mesh bags (such as allowing manual or robotic arms to enter the inter - layer area), reducing the downtime for maintenance.

[0131] Backwashing effect: At this spacing, the backwashing water (or gas) can uniformly penetrate each sieve pocket layer, avoiding backwashing blind spots caused by insufficient spacing, and increasing the activated carbon regeneration efficiency by 15 - 20%.

[0132] Beneficial effects include:

[0133] 1. Improvement in mass transfer efficiency and reaction rate

[0134] When the layer spacing increases from 0.2 m to 0.3 m, the COD removal rate increases from 92% to 96%, the reaction rate constant (k) increases from 0.28 d-1 to 0.35 d-1, and the hydraulic retention time (HRT) is shortened by 20%.

[0135] Reason:

[0136] At a spacing of 0.3 m, the substrate diffusion coefficient (D) is approximately 10 -6 cm 2 / s, which is 25% higher than that at a spacing of 0.2 m (D ≈ 8×10 -7 cm 2 / s), promoting the mass exchange between microorganisms and the surface of activated carbon.

[0137] 2. Enhancement of system stability and shock resistance

[0138] Anti-blocking performance: A spacing of 0.3 m can accommodate more suspended solids (such as sludge and fibers) to pass through, reducing the risk of blockage between sieve pocket layers. In the experiment, after continuous operation for 180 days, the pressure drop of the 0.3 m spacing system only increased by 0.5 kPa, while that of the 0.2 m spacing system increased by 2.0 kPa.

[0139] pH buffering capacity: After the spacing is enlarged, the fluid mixing is more sufficient, and the risk of local acidification is reduced. For example, under the condition of a ±30% fluctuation in the influent COD, the pH fluctuation range of the 0.3 m spacing system is <0.2, while that of the 0.2 m spacing system reaches 0.5.

[0140] 3. Reduction of long-term operating costs

[0141] Backwashing energy consumption: At a spacing of 0.3 m, the backwashing water pressure can be reduced to 0.15 MPa (a 40% reduction compared to 0.25 MPa at a spacing of 0.2 m), and the backwashing energy consumption per ton of water is reduced from 0.5 kWh to 0.3 kWh, saving about 10 - 15% in annual electricity costs.

[0142] Prolongation of activated carbon life: After the spacing is optimized, the surface wear of the activated carbon is reduced, and the service life is extended from 2 years to 3 - 4 years. The amortization cost of activated carbon in the unit treatment cost is reduced by 30 - 40%.

[0143] 4. Improvement in biogas production and quality

[0144] Biogas production efficiency: With a 0.3 m spacing, through optimizing mass transfer and mixing, the biogas production per unit COD increases from 0.3 m 3 / kg to 0.33 m 3 / kg, a 10% increase.

[0145] Methane purity: The methane content in biogas increases from 60% to 65%. Due to the enlarged spacing, the retention of CO2 between the mesh layers is reduced, promoting the metabolism of methanogens.

[0146] In a specific feasible embodiment, the DIET anaerobic reaction zone and the anammox reaction zone are arranged in a front-back coupling manner; its beneficial effects include:

[0147] I. Process synergy and efficiency improvement: Simultaneous removal of organic matter and nitrogen

[0148] DIET reaction zone: Degradation of organic matter and generation of electron donors;

[0149] ; DIET relies on conductive materials (such as granular activated carbon, biochar) or conductive microbial communities (such as Geobacter, Methanosaeta) to achieve anaerobic oxidation of organic matter (such as volatile fatty acids VFA) and directly transfer electrons to methanogens or denitrifying bacteria.

[0150] Anammox reaction zone: Deep removal of nitrogen

[0151] Utilize NH4 in the effluent of the DIET reaction zone + and partially generated NO2 - (or supplemented by shortcut nitrification), and through Anammox bacteria (such as Candidatus Kuenenia), achieve NH4 + +NO2 - →N2 + 2H2O.

[0152] Coupling advantages:

[0153] The DIET reaction zone consumes organic matter, avoiding its inhibition of Anammox bacteria (the tolerance of Anammox bacteria to organic matter is <50 mg COD / L);

[0154] The generated H2 or small molecular organic acids can promote the activity of shortcut nitrifying bacteria (AOB) and stably provide NO2 - .

[0155] II. Improvement of operation stability: Shock resistance and pH buffering

[0156] Resistance to organic load fluctuations

[0157] DIET pretreatment: Degrade most of the easily degradable organic matter through the DIET reaction zone (e.g., COD removal rate > 70%), reducing the risk of organic matter shock in the subsequent Anammox reaction zone.

[0158] The pH of the coupled system is stabilized at 7.5 - 8.0, saving 40 - 50% of the alkalinity cost compared to a single Anammox system (which requires additional alkalinity addition).

[0159] III. Resource Recovery and Cost Reduction

[0160] Methane production by DIET: The methane production rate in the coupled system can reach 0.2 - 0.3 m 3 CH4 / kg COD, a 20 - 30% increase compared to traditional anaerobic digestion, and can be directly used for power generation or heating.

[0161] Nitrogen recovery: The by - product of the Anammox reaction zone is N2, reducing carbon emissions by 60 - 70% compared to traditional nitrification - denitrification (which requires carbon source addition).

[0162] IV. Process Flexibility and Footprint Optimization

[0163] The DIET reaction zone consumes organic matter, and the Anammox zone focuses on nitrogen removal;

[0164] A short - cut nitrification unit can be added, and the DIET zone provides H2 to promote the activity of AOB.

[0165] Front - to - back coupled reactors: The DIET and Anammox zones can be integrated into the same reactor (separated by a baffle) or arranged in series, reducing the floor area by 30 - 50% compared to traditional separate processes (hydrolysis acidification + A / O + Anammox).

[0166] In a specific feasible implementation, a honeycomb - shaped polyethylene packing box is provided in the anaerobic ammonium oxidation reaction zone.

[0167] Specifically, a honeycomb - shaped polyethylene packing box is provided in the anaerobic ammonium oxidation (Anammox) reaction zone, and its beneficial effects include:

[0168] I. Core Functions and Structural Advantages

[0169] High specific surface area and microbial attachment

[0170] Honeycomb structure characteristics: The polyethylene packing box adopts a hexagonal honeycomb pore design, with a specific surface area of up to 200 - 300 m 2 / m 3 , compared to traditional packings (such as multi - faceted hollow balls, with a specific surface area of about 50 - 100 m 2 / m 3) It is increased by 2 - 3 times. The pore diameter is usually 10 - 20 mm, which can effectively intercept anaerobic ammonium - oxidizing bacteria (AnAOB) and nitrifying bacteria, forming a high - density biofilm (biomass can reach 15 - 20 g VSS / L), and the biomass is increased by 5 - 8 times compared with the suspended - growth system.

[0171] Microbial immobilization: The inner wall roughness of the honeycomb pore is Ra 3 - 5 μm, which is conducive to the secretion of extracellular polymeric substances (EPS) by microorganisms to form a stable biofilm and reduce the loss of bacterial flora. Experiments show that the abundance of Anammox bacteria in the packing box can reach 10 10 -10 11 copies / g, which is 1 - 2 orders of magnitude higher than that of the suspended system.

[0172] Fluid homogenization and mass transfer enhancement

[0173] Flow pattern optimization: The honeycomb pores can guide the water flow to rise in a spiral or laminar distribution, avoiding short - circuit flow and dead zones. CFD simulation shows that the turbulent kinetic energy (TKE) of the fluid in the packing box is increased by 40 - 60% compared with the non - packing area, promoting the contact between the substrate (NH4 + 、NO2 - ) and microorganisms.

[0174] Enhanced mass transfer coefficient: The diffusion distance of the substrate in the pores is shortened to 1 - 2 mm (5 - 10 mm in the traditional suspended system), and the mass transfer coefficient (kL) from the liquid phase bulk to the biofilm increases from 0.01 - 0.02 cm / s to 0.05 - 0.08 cm / s, and the removal rate of NH4 + is increased by 3 - 5 times.

[0175] Enhanced shock - load resistance and stability

[0176] Buffering effect: The biofilm in the packing box can store 10 - 15% of the influent substrate (such as NH4 + ). When the influent load fluctuates (such as the concentration of NH4 + ±30%), the substrate stored in the biofilm can maintain the metabolism of the bacterial flora, and the fluctuation range of the effluent TN is reduced by 50 - 70%.

[0177] Adsorption of toxic substances: The polyethylene material has an adsorption rate of 60 - 80% for heavy metals (such as Cu 2+ 、Zn 2+ ) and organic poisons (such as phenol), reducing their inhibition on Anammox bacteria. In the experiment, when the influent phenol concentration is 50 mg / L, the Anammox activity of the packing - box system still remains above 80%, while the activity of the non - packing system drops to 40%.

[0178] II. Technical advantages and data support

[0179] Significantly improved denitrification efficiency

[0180] TN removal rate: The TN removal rate of the packing box system can reach 90 - 95%, which is 10 - 15 percentage points higher than that of the suspended system (about 80 - 85%). The key reasons include:

[0181] The activity of Anammox bacteria in the biofilm increases (specific activity reaches 0.2 - 0.3 g N / (g VSS·d), while that of the suspended system is 0.1 - 0.15 g N / (g VSS·d));

[0182] The DO gradient distribution in the pores (outer layer < 0.1 mg / L, inner layer < 0.05 mg / L) avoids the competition of aerobic bacteria.

[0183] Nitrogen production rate: For every 1 mg of NH4 + -N removed, 0.86 - 0.88 mg of N2 can be produced (the theoretical value is 0.886 mg of N2), and the nitrogen purity (the proportion of N2) reaches more than 98%, reducing the emission of greenhouse gas N2O.

[0184] Reduction of operating cost and energy consumption

[0185] Savings in aeration energy consumption: The packing box system does not require additional aeration (Anammox is an anaerobic process), saving 100% of the aeration energy consumption compared with the traditional nitrification - denitrification process.

[0186] Reduction of chemical costs: There is no need to add carbon sources (such as methanol) or alkalinity (such as NaHCO3), and the chemical costs are reduced by 70 - 90%.

[0187] Decrease in sludge production: The yield coefficient (Y) of Anammox bacteria is only 0.066 - 0.11 kg VSS / kg N, reducing the sludge production by 60 - 80% compared with denitrifying bacteria (Y = 0.3 - 0.5), and reducing the disposal cost.

[0188] Improvement of system stability and extension of service life

[0189] Anti - clogging ability: The honeycomb pore diameter of 10 - 20 mm can effectively intercept suspended solids (such as SS < 5 mg / L), and the backwashing cycle is extended to 3 - 6 months (the traditional packing is 1 - 2 months), reducing the downtime for maintenance.

[0190] Service life of the packing: The polyethylene material is corrosion - resistant and anti - aging, and its service life can reach 10 - 15 years, reducing the cost by 50 - 70% compared with fillers such as ceramsite and activated carbon (service life of 3 - 5 years).

[0191] In a specific feasible embodiment, a sodium alginate - bentonite composite gel layer is provided on the inner wall of the honeycomb - shaped polyethylene packing box.

[0192] Specifically, when a sodium alginate - bentonite composite gel layer is provided on the inner wall of the honeycomb - shaped polyethylene packing box, the beneficial effects include:

[0193] I. Function Enhancement: Synergistic Effect of Adsorption and Retention

[0194] Efficient Adsorption of Pollutants

[0195] Fixation of Ammonia Nitrogen and Nitrite: The bentonite layer contains a montmorillonite mineral structure, and the interlayer cations (such as Na + 、Ca 2+ ) can exchange and adsorb NH4 + , with an adsorption capacity of 15 - 20 mg NH4 + / g bentonite, which is 3 - 5 times higher than that of a single polyethylene filler. The carboxyl group (-COOH) of sodium alginate can complex with NO2 - , reducing the inhibition of Anammox bacteria caused by its accumulation (the inhibition threshold of NO2 - is increased from <10 mg / L to <20 mg / L).

[0196] Removal of Heavy Metals and Organic Poisons: The adsorption rate of bentonite for Cu 2+ 、Zn 2+ reaches 80 - 90%. The hydroxyl group (-OH) of sodium alginate can entrap organic substances such as phenol. When the influent phenol concentration is 50 mg / L in the experiment, the composite gel layer can extend the penetration time of toxic substances by 2 - 3 times, protecting the activity of the bacterial community.

[0197] Attachment and Protection of Microorganisms

[0198] Three - dimensional Network Structure: After cross - linking, sodium alginate forms a porous gel network (pore size 1 - 5 μm), providing anchoring sites for Anammox bacteria. The thickness of the biofilm can reach 50 - 100 μm, which is 1 - 2 times thicker than that of the filler without a gel layer (20 - 30 μm).

[0199] Enhanced Shear Resistance: The elastic modulus of the gel layer is 0.1 - 0.3 MPa, which can buffer the impact of water flow and reduce the shedding of the biofilm. In the experiment, when the hydraulic shear force increases from 5 - 10 N / m 2 to 15 - 20 N / m 2 , the biofilm retention rate of the gel layer system is still higher than 90%, while that of the system without a gel layer drops to 60 - 70%.

[0200] II. Efficiency Improvement: Acceleration of Mass Transfer and Metabolism

[0201] Optimization of Matrix Diffusion and Reaction Rate

[0202] Construction of Gradient Concentration Field: The outer layer of the gel layer adsorbs NH4 + 、NO2 -, a high-concentration matrix microenvironment is formed, and the matrix concentration gradient in the inner biofilm reaches 5 - 10 mg / L / mm, promoting the Anammox reaction rate (the specific activity is increased to 0.25 - 0.3 g N / (gVSS·d), which is 20 - 30% higher than that of the system without the gel layer).

[0203] pH buffering effect: Al released by bentonite 3+ and Mg 2+ can neutralize the metabolic acid production with the carboxyl groups of sodium alginate, maintaining the system pH at 7.5 - 8.0, and reducing the pH fluctuation range by 40 - 50% compared with the system without the gel layer.

[0204] The start-up period is shortened

[0205] Rapid enrichment of the microbial community: The surface of the gel layer is negatively charged (-30~-40 mV), which can electrostatically adsorb positively charged Anammox bacteria (such as Candidatus Brocadia), and the biofilm formation time of the microbial community is shortened from 30 - 45 days to 15 - 20 days.

[0206] Enhanced low-temperature adaptability: At a low temperature of 10 - 15 °C, the water retention capacity of the gel layer (water content > 90%) can maintain the metabolic activity of the microbial community, and the TN removal rate is increased by 10 - 15% compared with the system without the gel layer.

[0207] III. Improvement of stability: Impact resistance and long-term operation

[0208] Capacity to resist load fluctuations

[0209] Matrix buffer pool effect: The gel layer can store 10 - 15% of the influent NH4 + (adsorption capacity reaches 5 - 8 mg NH4 + / g gel). When the influent NH4 + concentration fluctuates by ±30%, the fluctuation range of the effluent TN concentration decreases from ±15% to ±5%.

[0210] Resistance to toxic shock: When the influent phenol concentration increases from 0 to 100 mg / L, the Anammox activity retention rate of the gel layer system is still higher than 70%, while the activity of the system without the gel layer drops to <40%.

[0211] Service life and maintenance cost reduction

[0212] Anti-biodegradability: After sodium alginate is cross-linked with glutaraldehyde, the biodegradation rate drops from 80 - 90% to <10%, the gel layer life is extended to 3 - 5 years, and the cost is reduced by 60 - 70% compared with unmodified sodium alginate (<1 year).

[0213] Improved backwashing efficiency: The smoothness of the gel layer surface (Ra < 1 μm) reduces fouling attachment, the water consumption for backwashing is reduced by 30 - 40%, and the backwashing cycle is extended to 4 - 6 months.

[0214] In a specific feasible embodiment, a microporous aeration system is provided in the anaerobic ammonium oxidation reaction zone.

[0215] Specifically, a microporous aeration system is provided in the anaerobic ammonium oxidation (Anammox) reaction zone, and the beneficial effects include:

[0216] I. Function optimization: Precise oxygen control and microbial community synergy

[0217] Construction of local micro-oxygen environment

[0218] DO gradient control: The microporous aerator (pore diameter <50 μm) can generate microbubbles with a diameter of 0.5 - 2 mm. By adjusting the gas-water ratio (1:2 - 1:5), the DO concentration in the reaction zone can be precisely controlled at 0.05 - 0.2 mg / L, meeting the activity requirements of short-range nitrifying bacteria (AOB) (DO > 0.02 mg / L), and at the same time inhibiting the competition of aerobic bacteria (such as NOB) (NOB is active when DO > 0.5 mg / L).

[0219] Enrichment of microbial communities in different zones: During the rising process of microbubbles, a DO concentration gradient is formed. AOB (NH4 + →NO2 - ) is enriched at the bottom (aeration zone) of the reactor, and Anammox bacteria (NH4 + +NO2 - →N2) are enriched in the middle and upper parts (anaerobic zone), realizing "one reactor, two zones" synergistic denitrification, saving 30 - 50% of the floor area compared with the traditional two-stage process.

[0220] Improvement of substrate conversion efficiency

[0221] Stable supply of nitrite: The micro-aeration system can convert 40 - 60% of the influent NH4 + into NO2 - , and the NO2 - generation rate reaches 0.1 - 0.2 kg NO2 - / (m 3 ·d), which is 50 - 80% higher than the traditional short-range nitrification process (requiring an independent reactor), meeting the requirements of Anammox bacteria for the substrate ratio (NH4 + :NO2 - ≈1:1.32).

[0222] pH buffering effect: The acid produced during nitrification (H + ) and the base produced during Anammox (OH - ) are partially neutralized in the micro-aeration system, maintaining the pH stable at 7.5 - 8.0 and reducing the alkalinity dosage by 30 - 40%.

[0223] II. Efficiency improvement: Enhanced mass transfer and accelerated reaction

[0224] Optimization of Fluid Mixing and Mass Transfer

[0225] Enhancement of Turbulence Intensity: The rising speed of microbubbles is 2 - 5 cm / s, reducing the shear force compared with traditional aeration (10 - 15 cm / s). However, through a high - density bubble swarm (gas holdup of 5 - 10%), the turbulent kinetic energy (TKE) of the liquid phase is increased by 30 - 50%, promoting the contact between the substrate (NH4 + , NO2 - ) and microorganisms.

[0226] Improvement of Oxygen Utilization Efficiency: The oxygen transfer efficiency (OTE) of the micro - aeration system reaches 25 - 30%, which is 1 - 2 times higher than that of coarse - bubble aeration (10 - 15%). The energy consumption per unit denitrification is reduced by 40 - 50% (when removing 1 kg of TN, the energy consumption is reduced from 1.5 - 2.0 kWh to 0.8 - 1.2 kWh).

[0227] Reaction Rate and Denitrification Load

[0228] Total Nitrogen Removal Rate (TN): The TN removal rate of the micro - aeration system can reach 85 - 90%, which is 10 - 15 percentage points higher than that of the pure anaerobic Anammox system (70 - 80%). The key reasons include:

[0229] The synergistic effect of AOB and Anammox bacteria shortens the reaction path (traditional nitrification - denitrification requires 4 steps, while the micro - aeration system only requires 2 steps); NO2 is adsorbed on the surface of microbubbles - , reducing its escape loss (the utilization rate of NO2 - is increased to more than 90%).

[0230] Volumetric Load:

[0231] The TN volumetric load of the reactor can reach 0.8 - 1.2 kg N / (m 3 ·d), which is 2 - 3 times higher than that of the traditional process (0.3 - 0.5 kg N / (m 3 ·d)), and is suitable for the treatment of high - ammonia - nitrogen wastewater (such as landfill leachate, coking wastewater).

[0232] III. Operational Stability: Shock Resistance and Long - term Maintenance

[0233] Shock Resistance to Load Fluctuations

[0234] Dynamic DO Regulation: Through the linkage of on - line DO monitoring and gas volume regulating valve, when the influent NH4 + concentration fluctuates by ±30%, the system can adjust the DO to the target range within 10 - 15 minutes, and the fluctuation range of the TN removal rate is reduced from ±15% to ±5%.

[0235] Toxic substance tolerance: The upflow generated by micro-aeration can carry some volatile poisons (such as H2S and benzene series) out. Combining with the tolerance of AOB to organic matter (BOD5 / N < 0.15), the system can still operate stably when the influent COD reaches 200 - 300 mg / L, and the anti-organic load capacity is 1 - 2 times higher than that of a pure anaerobic system.

[0236] Sludge reduction and system life

[0237] Surplus sludge production: The combined action of AOB and Anammox bacteria reduces the sludge production coefficient (Y) to 0.1 - 0.15 kgVSS / kg N, which is 60 - 80% less than that of the traditional nitrification and denitrification process (Y = 0.3 - 0.5), reducing the disposal cost.

[0238] Anti-blocking of aerators: The microporous material is coated with an anti-scaling coating (such as TiO2). Combining with regular reverse pulse cleaning (frequency: once a week), the clogging period of the aerator is extended to 1 - 2 years, and the maintenance cost is reduced by 70 - 80% compared with traditional aerators (3 - 6 months).

[0239] In a specific feasible embodiment, the activated carbon mesh bag is made of stainless steel.

[0240] Specifically, the activated carbon mesh bag is made of stainless steel, and its beneficial effects include:

[0241] Corrosion resistance

[0242] Material advantages: Stainless steel (such as 304 or 316L) contains Cr and Ni elements, and a dense oxide film is formed on the surface, which is resistant to acid and alkali corrosion (pH 2 - 12). In an environment with fluctuating wastewater pH (such as pH 7.5 - 8.5 in the Anammox system) and microbial metabolites (such as H2S and organic acids), the corrosion rate is < 0.01 mm / year, and the service life is more than 10 times longer than that of carbon steel (> 0.1 mm / year).

[0243] Load-bearing and anti-deformation: The yield strength of stainless steel ≥ 205 MPa, which can withstand the activated carbon filler (density 0.4 - 0.6 g / cm 3 ) and the water flow impact force (flow velocity 0.5 - 1.5 m / s). The deformation rate of the mesh bag is < 1%, avoiding the collapse or rupture of traditional plastic mesh bags (such as PP) caused by long-term stress.

[0244] Anti-wear property: Under the action of water flow shear force (10 - 20 N / m 2 ) and particle friction, the surface hardness of stainless steel (HV 180 - 220) can reduce wear, and the service life is 3 - 5 times longer than that of plastic mesh bags (HV 50 - 80).

[0245] Specifically, in one feasible implementation, the biochemical reactor system for domestic waste leachate includes:

[0246] Integrated reactor: Cuboid-shaped steel structure, with a total height of 8 m, a width of 4 m, and a length of 12 m. It is divided into two areas, the front area of 4 m is the DIET anaerobic area, and the rear area of 8 m is the Anammox area;

[0247] Activated carbon mesh bag: The particle size of the filled activated carbon particles is adjusted to 1 - 3 mm, and the specific surface area is ≥1500 m 2 / g, and the filling rate is increased to 70%; the layer spacing of the mesh bags is 0.3 m, with a total of 15 layers, forming a dense electron transfer network to improve the DIET efficiency;

[0248] Mesh box packing: In the Anammox area, honeycomb-shaped polyethylene packing boxes (specific surface area 800 m 2 / m 3 ) are arranged, and the inner wall of the box is pre-coated with sodium alginate-bentonite composite gel to immobilize Anammox bacteria.

[0249] Furthermore, the integrated reactor includes two main parts. One is the direct interspecies electron transfer anaerobic reactor, whose main function is to remove organic carbon pollutants in the leachate, such as COD, BOD, etc. The other is the anaerobic ammonium oxidation reactor, which mainly removes nitrogen-containing pollutants in the leachate.

[0250] In the anaerobic methane production system, the electron transfer between bacteria and methanogens has always been considered to be achieved through interspecies H2 / formate transfer. However, in recent years, studies have found that there is a direct interspecies electron transfer (DIET) between some electroactive microorganisms and methanogens that can replace interspecies H2 / formate transfer to achieve electron transfer. The conductive medium-packed anaerobic reactor applies the above principle and sets activated carbon packing in the form of hanging parts in the reactor tank to promote direct electron transfer between microorganisms, thereby shortening the lag time of methane production, increasing the methane production rate, and increasing the amount of methane production. From the perspective of pollutant removal effect, it can significantly shorten the hydraulic retention time for treating organic pollutants.

[0251] Adopt a mesh bag structure filled with activated carbon particles as the electron transfer medium to construct a direct interspecies electron transfer (DIET) network to replace the traditional IHT mechanism.

[0252] In the anaerobic reactor, an upflow water distribution method is adopted to arrange activated carbon mesh bags. Multiple layers of stainless steel mesh bags (pore size 5 - 10 mm) are set in the reactor, and conductive activated carbon particles (particle size 1 - 3 mm, specific surface area ≥1500 m 2 / g), with the activated carbon dosing concentration of 15 - 20 g / L in the leachate, to promote the direct electron transfer between electricity-producing bacteria (such as Geobacter) and methanogens. During the upward circulation of the water body, the microorganisms in the water body are evenly adsorbed on the activated carbon filler in the box, and the water body is in full contact with the filler.

[0253] Using the activated carbon-mediated effect, the methane production rate of methanogens increases by 50 - 100%; compared with the traditional anaerobic fermentation tank, the hydraulic retention time is shortened by 25 - 50%, the tank volume can be reduced by 50%, and the floor area is reduced by 60%.

[0254] Carbon-nitrogen ratio regulation: Accelerate the degradation of volatile fatty acids (VFAs) through DIET to reduce the effluent C / N to below 2.5, directly meeting the influent requirements of anaerobic ammonium oxidation (Anammox). That is, for the leachate treated by the anaerobic part of the coupled reactor, the COD concentration can be reduced from 30000 - 60000 g / m 3 to 2000 - 5000 g / m 3 , the NH3 concentration in the water body is 1500 - 2500 g / m 3 , and at this time, the carbon-nitrogen ratio of the wastewater is less than 2.5. The wastewater enters the second stage of the occasional reactor, the anaerobic ammonium oxidation reaction zone.

[0255] Furthermore, an integrated structure of anaerobic ammonium oxidation - anaerobic reactor is adopted:

[0256] Anaerobic ammonium oxidation mainly relies on autotrophic microorganisms to remove nitrogen-containing pollutants in the water body. Since it is autotrophic, it does not require a carbon source. The low carbon-nitrogen ratio of the water body after the first-stage reaction is beneficial to inhibiting the reproduction of heterotrophic microorganisms, thus ensuring the stability of the autotrophic microbial colony.

[0257] The DIET anaerobic reaction zone and the anaerobic ammonium oxidation reaction zone are parallelly stacked to form a front-back partition integrated reactor: the front part is the DIET anaerobic zone: highly loaded with organic matter degradation (COD load can reach 15 kg / (m 3 ·d)), and simultaneously produce biogas methane (CH4 production rate ≥ 0.3 L / g COD). The effluent from the anaerobic zone overflows into the rear anaerobic ammonium oxidation reaction zone.

[0258] In the second-stage reactor at the rear, honeycomb box fillers (pore diameter 1 - 2 mm) made of polyethylene are set, which is beneficial to the attachment of autotrophic anaerobic ammonium oxidation bacteria, with fewer miscellaneous bacteria, loaded with anaerobic ammonium oxidation bacteria (Candidatus Brocadia) biofilm, and the anaerobic ammonium oxidation activity can reach 6 mg / g·h. Using NH4 in the anaerobic effluent + and NO2 - to achieve autotrophic denitrification (denitrification rate ≥ 0.5 kg N / (m 3 ·d).

[0259] A microporous aeration system is set at the bottom of the pool body to maintain the dissolved oxygen content in the water body at less than 0.5 mg / L, preventing the excessive reproduction of aerobic heterotrophic microorganisms caused by too high dissolved oxygen concentration.

[0260] In this embodiment, the beneficial effects include:

[0261] Energy saving, where aerobic aeration changes to micro dissolved oxygen, the DO drops from above 2 to below 0.5, and the energy consumption is reduced by no less than 60%; the DIET electron transfer efficiency is increased by 3 - 5 times compared with IHT, and the reactor volume is reduced by 40%.

[0262] Low carbon, reducing the addition of carbon sources (the chemical agent cost is reduced by 70%), avoiding N2O emissions (emission reduction by 90% compared with the traditional process); the recovery rate of biogas is increased by 20%, realizing the carbon resource utilization.

[0263] Stability, the activated carbon mesh bag enhances the ability to withstand shock loads, and can withstand a COD fluctuation range of ±30%; Anammox bacteria form a high-density biofilm in the reticulated packing (biomass ≥ 15 g / L), and are resistant to low temperatures (the denitrification efficiency still reaches 80% at 15°C).

[0264] In Figure 2 this application embodiment provides a biochemical reaction method for domestic waste leachate, including the following steps:

[0265] Using the DIET anaerobic reaction zone to degrade the organic matter in the domestic waste leachate;

[0266] Using the anaerobic ammonium oxidation reaction zone to carry out denitrification treatment on the domestic waste leachate.

[0267] In the above technical solution, by setting an integrated reactor, the integrated reactor is provided with: a DIET anaerobic reaction zone for degrading the organic matter in the domestic waste leachate; an anaerobic ammonium oxidation reaction zone for carrying out denitrification treatment on the domestic waste leachate; improving the removal efficiency of organic pollutants and total nitrogen in the leachate treatment process, improving the biogas production efficiency, reducing the energy consumption, reducing the carbon emissions, and reducing the pool body volume, thereby reducing the land occupation scale and investment and operation costs.

[0268] Those skilled in the art of the present application know that the present application can be implemented as a system, a method or a computer program product.

[0269] Thus, the present disclosure can be specifically implemented in the following forms, i.e., it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, which is generally referred to as "circuit", "module" or "system" herein. In addition, in some embodiments, the present application can also be implemented in the form of a computer program product in one or more computer-readable media, which contain computer-readable program codes.

[0270] Any combination of one or more computer-readable media can be adopted. The computer-readable media can be computer-readable signal media or computer-readable storage media. The computer-readable storage media can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage media can be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0271] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application. On this basis, various substitutions and improvements can be made to the present application, and these all fall within the protection scope of the present application.

Claims

1. A biochemical reactor system for domestic waste leachate, characterized in that, Comprising: an integrated reactor, wherein in the integrated reactor are provided with: a DIET anaerobic reaction zone for degrading organic matters in domestic waste leachate; an anaerobic ammonium oxidation reaction zone for denitrifying the domestic waste leachate.

2. The biochemical reactor system for domestic waste leachate according to claim 1, characterized in that, In the DIET anaerobic reaction zone are provided with: activated carbon mesh bags for forming an electron transfer network.

3. The biochemical reactor system for domestic waste leachate according to claim 2, characterized in that, The particle size of the activated carbon is 1 - 3 mm.

4. The biochemical reactor system for domestic waste leachate according to claim 3, characterized in that, The activated carbon mesh bags are arranged in layers, and the distance between the activated carbon mesh bag layers is not less than 0.3 m.

5. The biochemical reactor system for domestic waste leachate according to claim 4, characterized in that, The DIET anaerobic reaction zone and the anaerobic ammonium oxidation reaction zone are arranged in a front - rear coupling manner.

6. The biochemical reactor system for domestic waste leachate according to claim 5, wherein, In the anaerobic ammonium oxidation reaction zone is provided with a honeycomb polyethylene packing box.

7. The biochemical reactor system for domestic waste leachate according to claim 6, characterized in that, On the inner wall of the honeycomb polyethylene packing box is provided with a sodium alginate - bentonite composite gel layer.

8. The biochemical reactor system for domestic waste leachate according to claim 7, wherein, In the anaerobic ammonium oxidation reaction zone is provided with a microporous aeration system.

9. The biochemical reactor system for domestic waste leachate according to claim 8, wherein, The activated carbon mesh bags are made of stainless steel.

10. A biochemical reaction method for domestic waste leachate, characterized in that, Comprising the following steps: Using the DIET anaerobic reaction zone to degrade organic matters in domestic waste leachate; Using the anaerobic ammonium oxidation reaction zone to denitrify the domestic waste leachate.

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