Livestock farm ammonia-containing odor treatment and washing liquid regeneration device

Abstract

The application provides a livestock and poultry farm ammonia-containing odor treatment and washing liquid regeneration device, and belongs to the field of breeding pollution odor treatment. The device comprises a first washing assembly connected with an odor source of a farm, a first washing assembly removes feed dust in the odor to form a first washing liquid; a second washing assembly is connected behind the first washing assembly, the second washing assembly absorbs ammonia in the odor and transfers the ammonia to a liquid phase, and the second washing assembly oxidizes ammonia in the liquid phase to form a second washing liquid; a first sedimentation tank is connected behind the first washing assembly and connected with a sewage source of the farm, the first sedimentation tank simultaneously receives the first washing liquid and the sewage source to perform sedimentation and form a first tail water; a circulating assembly is connected behind the first sedimentation tank and connected with water outlet of the second washing assembly, the circulating assembly mixes the second washing liquid and the first tail water to form a second tail water, the circulating assembly performs denitrification and mud-water separation on the second tail water to form a regenerated liquid, and the regenerated liquid is transported to the first washing assembly and the second washing assembly and used for odor washing.

Description

Technical Field

[0001] The present invention relates to the technical field of odor pollution treatment in livestock and poultry farms, and in particular to a device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms. Background Art

[0002] Odor emissions from large-scale farms are high in volume, low in concentration, and complex in composition, with ammonia being the primary component. Currently, most odor treatment methods for large-scale farms focus solely on removing components of the odor (such as ammonia), relying on inexpensive clean water, chemicals, or biological treatment technologies. However, these technologies fail to effectively combine the physical absorption of ammonia from the odor with biological oxidation under acidic conditions to reduce operating or investment costs. Furthermore, current deodorization technologies fail to adequately address the large amounts of nitrogen-containing washing liquid generated during the deodorization process, leading to secondary pollution and high disposal costs.

[0003] In view of this, the art urgently needs a combined process suitable for regenerating ammonia-containing odor and its washing liquid in large-scale farms, which aims to solve: (1) the sustainability of ammonia removal in pig farms while solving the problem of washing liquid regeneration treatment; (2) reduce the operating cost of treating ammonia-containing odor and its washing liquid. Summary of the Invention

[0004] In view of this, the present invention proposes a device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms, which is used to solve the inherent defects of current farm odor treatment technology that relies on a single technical means (such as clean water absorption, chemical absorption and oxidation or biological treatment), as well as the problem of regenerating a large amount of nitrogen-containing washing liquid generated during the deodorization process.

[0005] The technical solution of the present invention is achieved as follows: The present invention provides a device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms, comprising a first washing component connected to the odor source of the farm, the first washing component removing feed dust from the odor to form a first washing liquid; a second washing component connected after the first washing component, the second washing component absorbing ammonia in the odor and transferring the ammonia to a liquid phase, the second washing component oxidizing the ammonia in the liquid phase to form a second washing liquid; a first sedimentation tank connected after the first washing component and connected to the sewage source of the farm, the first sedimentation tank simultaneously receiving the first washing liquid and the sewage source for sedimentation to form a first tail water; a circulation component connected after the first sedimentation tank and connected to the effluent of the second washing component, the circulation component mixing the second washing liquid and the first tail water to form a second tail water, the circulation component denitrifying, short-range nitrifying and mud-water separation of the second tail water to form a regenerated liquid, the regenerated liquid being transported to the first washing component and the second washing component and used to wash the odor.

[0006] On the basis of the above technical solution, preferably, the first washing component includes a first water curtain wall, which is arranged facing the flow direction of the odor, and the first water curtain wall removes feed dust in the odor by spraying water curtains; a first circulation pool is arranged below the first water curtain wall and receives the washing water falling from the first water curtain wall to form a first washing liquid.

[0007] Further preferably, the second washing component includes a second water curtain wall, which is also arranged facing the flow direction of the odor, and the second water curtain wall absorbs ammonia in the odor by spraying a water curtain; a second circulation pool, which is arranged below the second water curtain wall and receives the washing water falling from the second water curtain wall; a filling frame, which is arranged in the second circulation pool, and the filling frame is provided with a filler with attached nitrifying bacteria and oxidizes the ammonia in the washing water to form a second washing liquid.

[0008] Further preferably, the circulation component includes a regulating tank, which is connected after the first sedimentation tank, and the first tail water in the first sedimentation tank flows into the regulating tank by gravity, and the second washing liquid of the second washing component is drained and injected into the regulating tank; a denitrification tank, which is connected after the regulating tank and denitrifies the second tail water; a second sedimentation tank, which is connected after the denitrification tank and performs mud-water separation on the second tail water after denitrification; a short-cut nitrification tank, which is connected after the second sedimentation and oxidizes the ammonia nitrogen in the second tail water into nitrite and performs mud-water separation again to obtain regenerated liquid; a reuse tank, which is connected after the short-cut nitrification tank and receives the regenerated liquid, and replenishes clean water to the reuse tank.

[0009] More preferably, the washing water used for the first water curtain wall comes from the first circulation pool; the washing water used for the second water curtain wall comes from the second circulation pool.

[0010] More preferably, a hydrolysis acidification tank is further included, which is connected between the sewage source and the first sedimentation tank. The hydrolysis acidification tank decomposes the macromolecular organic matter in the sewage into small molecular substances and converts the hydrolysis products into volatile fatty acids.

[0011] More preferably, an alkaline agent is added during the mixing process of the sewage and the first washing liquid in the first sedimentation tank to supplement the alkalinity of the first tail water.

[0012] More preferably, the DO in the regulating tank is controlled to be less than 0.2 mg / L, and the COD / NO3 in the regulating tank is controlled to be less than 0.2 mg / L. - -N is 2.0 to 4.0.

[0013] More preferably, a plurality of filler balls are arranged in the filler frame, the filler balls are filled with polyurethane sponge and nitrifying bacteria are attached to the polyurethane sponge, the filling rate of the filler frame is 20% to 35%, and the filling rate of the filler balls is 30% to 40%.

[0014] Further preferably, the volume of the reuse pool is greater than the sum of the volumes of the first circulation pool and the second circulation pool, and the first circulation pool or the second circulation pool has a preset water level; when the water level in the first circulation pool or the second circulation pool is lower than the preset water level, the reuse pool transports regeneration liquid to the first circulation pool or the second circulation pool; when the water level in the first circulation pool or the second circulation pool reaches the preset water level, the reuse pool stops transporting regeneration liquid to the first circulation pool or the second circulation pool.

[0015] The device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms of the present invention has the following beneficial effects compared with the prior art:

[0016] This invention combines ammonia absorption with biological oxidation processes, creatively developing the concept of "treating waste with waste." Simultaneously, based on anaerobic ammonia oxidation denitrification technology, it efficiently removes nitrogen from the washing liquid and reuses it in the deodorization process, achieving unified odor and wastewater treatment, eliminating secondary pollution, and providing a sustainable solution for ammonia removal in large-scale farms. Compared with existing processes, it has the following advantages:

[0017] (1) Ammonia removal efficiency is more stable. When using clean water to absorb ammonia, the pH value will increase, which will lead to a decrease in absorption efficiency. In the present invention, after ammonia is transferred from the gas phase to the liquid phase, the hydrolysis process will release OH - , the nitrifying bacteria attached to the filler can use NH4 + -N is used as a substrate to oxidize it into NO3 - -N, in this process, the alkalinity in the water is consumed, and H + Since the absorption and biological oxidation processes are carried out simultaneously and the H + Greater than the OH produced when ammonia dissolves in water - The dynamic weak acid absorption conditions of the washing liquid are maintained at the same time, and the dynamic and efficient removal of ammonia is ensured by combining absorption with biological oxidation.

[0018] (2) It has better economic benefits. On the one hand, the ammonia removal process adopted by the present invention no longer requires dilute acid chemicals to achieve ammonia removal, which can greatly save the cost of chemical consumption during operation. At the same time, the water in the absorption process mainly comes from the washing liquid regeneration system, which can save a lot of clean water. On the other hand, the present invention makes full use of the nutrients (including carbon sources, trace elements, phosphorus sources, etc.) in the wastewater discharged from the farm and uses the economical anaerobic ammonia oxidation denitrification technology to achieve the removal of nitrogen in the washing liquid, which can greatly save the cost of separate treatment of the washing liquid wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the connection relationship between the various components of the ammonia-containing odor treatment device of the present invention;

[0021] Figure 2 is a three-dimensional schematic diagram of a filling frame of the present invention;

[0022] Figure 3 This is a graph showing the ammonia removal performance of a typical piggery cycle according to the present invention;

[0023] Figure 4 This is a graph showing changes in pH and nitrogen in a typical cycle washing solution of the present invention;

[0024] Figure 5 Graph showing the total nitrogen removal performance of a typical periodic scrubbing liquid regeneration system of the present invention.

[0025] In the figure: 1. Odor source; 2. First washing component; 21. First water curtain wall; 22. First circulation tank; 3. Second washing component; 31. Second water curtain wall; 32. Second circulation tank; 33. Filling frame; 331. Filling balls; 4. Sewage source; 5. First sedimentation tank; 6. Circulation component; 61. Equalization tank; 62. Denitrification tank; 63. Second sedimentation tank; 64. Short-range nitrification tank; 65. Reuse tank; 7. Hydrolysis acidification tank. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, a device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms of the present invention comprises a first washing component 2, a second washing component 3, a first sedimentation tank 5, a circulation component 6 and a hydrolysis acidification tank 7.

[0028] The first washing component 2 is connected to the odor source 1 of the farm, and the first washing component 2 removes feed dust from the odor to form a first washing liquid.

[0029] The second washing assembly 3 is connected after the first washing assembly 2. The second washing assembly 3 absorbs ammonia in the odor and transfers the ammonia to the liquid phase. The second washing assembly 3 oxidizes the ammonia in the liquid phase to form a second washing liquid.

[0030] The first sedimentation tank 5 is connected after the first washing assembly 2 and to the farm's wastewater source 4. It receives both the first washing liquid and the wastewater source 4 for sedimentation, forming the first tailwater. The first sedimentation tank 5 is a coagulation and flocculation sedimentation tank, primarily removing small amounts of suspended matter from the effluent of the hydrolysis and acidification tank 7 and from the first washing liquid. The first sedimentation tank 5 comprises coagulation and flocculation tanks, as well as a sedimentation tank. The sedimentation tank is not limited to a specific type and can be either a vertical flow or horizontal flow sedimentation tank.

[0031] Preferably, conventional agents such as refined lime or compound alkali, polyacrylamide (PAM) can be used in the coagulation and flocculation tank. The addition concentration is determined according to the site conditions. The surface load of the first sedimentation tank should be 0.5 to 1.2 m 3 / (㎡·d);

[0032] Preferably, the pH value is monitored by an online pH probe and the dosage of the alkaline agent is adjusted, and the pH is preferably 6.5 to 8.0;

[0033] The circulation component 6 is connected after the first sedimentation tank 5 and is connected to the outlet water of the second washing component 3. The circulation component 6 mixes the second washing liquid and the first tail water to form the second tail water. The circulation component 6 denitrifies, short-range nitrifies and separates the mud and water on the second tail water to form a regeneration liquid. The regeneration liquid is transported to the first washing component 2 and the second washing component 3 and is used to wash odor.

[0034] The present invention mainly includes two parts: the first is the ammonia odor treatment system, including a two-stage washing component; the second is the washing liquid regeneration system, including a first sedimentation tank 5, a circulation component 6 and a hydrolysis acidification tank 7. The working process of the whole system is as follows:

[0035] (1) The odor generated by the poultry house and livestock house, which is the odor source 1, is drained by the exhaust duct and the fan into the odor treatment chamber, in which a two-stage washing component is arranged. Specifically, the odor first passes through the first washing component 2 to preliminarily remove the feed dust and a small amount of water-soluble components in the odor, and then enters the second washing component 3 for washing, so that the ammonia in the odor is transferred to the liquid phase. The ammonia in the liquid phase is oxidized by nitrifying bacteria and consumes the alkalinity in the washing liquid, thereby completing the dynamic absorption and oxidation of ammonia.

[0036] (2) The first washing liquid generated in the deodorization process and the sewage after hydrolysis and acidification (the sewage source 4 is usually the sewage storage tank of the farm sewage treatment station. The farm sewage treatment station will conduct preliminary treatment on the aquaculture sewage. The sewage has been filtered through a 0.5mm hydraulic screen, and the pig manure and crude fiber have been removed) together form the first tail water and enter the first sedimentation tank 5 (the first sedimentation tank 5 is generally a coagulation and flocculation sedimentation tank). The first tail water will flow into the circulation component 6 by gravity; the second washing liquid will be added to the circulation component 6 as a participant in balancing the water quality and form the second tail water. The tail water will complete the denitrification, — Short-range nitrification and mud-water separation, the resulting regeneration liquid, a portion of which is returned to the denitrification tank (62) in the circulation component 6 to provide NH4 + -N and NO2 - -N, and the other part of the regenerated liquid enters the reuse tank 65 and is transported to the two-stage washing component for cyclic washing, thereby achieving cyclic regeneration and utilization and realizing the purpose of "waste treatment with waste".

[0037] exist Figure 1 In a preferred embodiment shown, the first washing assembly 2 includes a first water curtain wall 21 and a first circulation pool 22 .

[0038] The first water curtain wall 21 is located in the direction of the odor flow. It removes feed dust from the odor by spraying water curtains. The first water curtain wall 21 uses intermittent or continuous spraying to keep the filler in a moist state, thereby capturing and intercepting large dust particles in the odor components. During intermittent spraying, the water pump on-off ratio is 0.2-1.0, and the spraying liquid-to-gas ratio is preferably 0.2-0.8L / m 3 The filler used in the first water curtain wall 21 includes but is not limited to honeycomb structured polypropylene (PP) filler, and the specific surface area should be greater than 250m 2 / m 3 The packing thickness should be 450mm, the packing empty bed wind speed should be 0.5~2m / s, and the packing empty bed residence time should be 0.5~2.0s.

[0039] The first circulation pool 22 is disposed below the first water curtain wall 21 and receives the washing water falling from the first water curtain wall 21 to form a first washing liquid.

[0040] The two-stage water curtain wall of the present invention has obvious functional differences: since the odor emitted from farms often contains feed dust, etc., the accumulation of feed dust can easily lead to clogging of the water curtain wall and thus reduce the absorption efficiency. Therefore, the first water curtain wall 21 is mainly used to remove dust, large particles and a small amount of odor components, and protect the filler in the second water curtain wall 31 from being blocked; the second water curtain wall 31 is the core unit responsible for ammonia absorption.

[0041] exist Figure 1In a preferred embodiment shown, the second washing assembly 3 includes a second water curtain wall 31 , a second circulation pool 32 and a filling frame 33 .

[0042] The second water curtain wall 31 is also positioned in the direction of the odor flow. It absorbs ammonia from the odor by spraying water curtains. Ammonia absorption is primarily accomplished in the second water curtain wall 31. Factors influencing absorption efficiency include the specific surface area of ​​the packing, wind speed, spray intensity (liquid-to-gas ratio), empty bed residence time of the packing, and pH of the absorbent. The second-stage water curtain wall pump operates continuously, achieving a continuous spraying mode. The spraying liquid-to-gas ratio is preferably 0.2 to 1.2 L / m 3 The filler used in the second water curtain wall 31 includes but is not limited to regular plastic filler, and the specific surface area should be greater than 250㎡ / m 3 The packing thickness should be 450mm~900mm, the packing empty bed wind speed should be 0.5~2m / s, and the packing empty bed residence time should be 0.5~2.0s.

[0043] The second circulation pool 32 is provided below the second water curtain wall 31 and receives the wash water falling from the second water curtain wall 31 .

[0044] The packing frame 33 is set in the second circulation pool 32. The packing frame 33 is provided with packing with nitrifying bacteria attached. At the same time, the nitrifying bacteria are also attached to the second-stage water curtain wall 31. The nitrifying bacteria attached to the packing in the packing frame 33 and the nitrifying bacteria attached to the second-stage water curtain wall 31 oxidize the ammonia in the second washing water to form a second washing liquid, the nitrogen-containing compound of which is mainly in the form of NH4 + -N and NO3 - -N. The nitrifying bacteria in the second water curtain wall 31 and the packing frame 33 are commercially available. The inoculation rate of the nitrifying bacteria in the packing frame 33 and the second water curtain wall 31 is 0.05% to 5% of the circulating water tank volume, and the effective viable bacterial count is 5 to 10 billion CFU / mL. During operation, the second washing liquid has a DO of 4.0 to 6.5 mg / L, a COD of 50 to 200 mg / L, a pH of 4.8 to 6.5, a TN of preferably ≤1000 mg / L, and NO3 - -N / NH4 + -N mass concentration ratio should be 1.0 to 1.5.

[0045] In the present invention, the physical absorption of ammonia is organically combined with the biological oxidation technology to maintain a dynamic weakly acidic environment (pH < 7.0), thereby further ensuring the efficient absorption of ammonia and the control of the nitrification process.

[0046] exist Figure 1 In a preferred embodiment shown, the circulation component 6 includes a regulating tank 61 , a denitrification tank 62 , a short-cut nitrification tank 64 and a reuse tank 65 .

[0047] The regulating tank 61 is connected after the first sedimentation tank 5 , and the first tail water in the first sedimentation tank 5 flows into the regulating tank 61 by gravity, and the second washing liquid of the second washing component 3 is drained and injected into the regulating tank 61 .

[0048] The denitrification tank 62 is connected to the regulating tank 61 and denitrifies the second tail water. The denitrification tank 62 is a short-range denitrification / anaerobic ammonium oxidation (PD / A) reaction tank, which can adopt a completely mixed reactor. After the second tail water from the regulating tank 61 enters the PD / A tank, the short-range denitrifying bacteria in the tank quickly complete the adsorption of most of the easily degradable organic matter and store it in the cells. At the same time, it uses this as a carbon source to convert most of the NO3 - -N is quickly reduced to NO2 - -N; in the available substrate NH4 + -N and NO2 - Under the condition of the presence of both -N, anaerobic ammonia oxidizing bacteria (AnAOB) attached to the filler and a small amount of AnAOB in the floc sludge will convert NH4 + -N and NO3 - NO2 produced by N reduction - -N converts nitrogen to form a PD / A process cycle, and the by-products produced in this process (NO3 - -N) and the remaining NH4 + -N enters the next PD / A process cycle again, and so on. Under carbon source limited conditions, a small amount of denitrifying bacteria in PD / A can synchronously convert NO x - -N(NO3 - -N and NO2 - -N) is converted into nitrogen gas to achieve the purpose of synergistic denitrification. The volatile suspended solids (MLVSS) in the PD / A pool of the denitrification tank 62 should be 2000-4500 mg / L, the DO in the pool during operation should be less than 0.1 mg / L, pH 6.5-8.0, and ORP should be less than 50 mV; the sludge return ratio should be 50%-150% (the ratio of the sludge return flow from the second sedimentation tank to the PD / A pool to the flow from the regulating tank to the PD / A pool); AnAOB inoculated fillers include but are not limited to biological ropes, polyurethane, etc., and the biomass attached to the inoculated fillers should not be less than 10 mgMLVSS / cm 3 The packing filling rate is 20% to 45%; the nitrogen load (NLR) of the reactor is preferably 0.5 to 2.0 kgN / (m 3 ·d).

[0049] The second sedimentation tank 63 is connected after the denitrification tank 62 and performs mud-water separation on the second tail water after denitrification.

[0050] The short-cut nitrification tank 64 is connected to the second sedimentation tank 63 to oxidize the ammonia nitrogen in the second tail water into nitrite and perform mud-water separation. Specifically, the short-cut nitrification tank 64 is a membrane-bioreactor (MBR) tank, which contains a mixture of flocculent sludge and water, wherein the flocculent sludge contains ammonia oxidizing bacteria (AOB) and aerobic heterotrophic bacteria. Under low oxygen conditions, aerobic heterotrophic bacteria can complete the oxidation of the remaining COD in the water from the denitrification tank, and similarly, AOB can also oxidize the remaining NH4 + -N is oxidized to NO2 - -N. The mud-water separation process in the short-range nitrification tank 64 is completed by the micron-level MBR membrane assembly (polymer hollow fiber membrane). That is, the water in the mud-water mixture in the short-range nitrification tank 64 is forced to pass through the MBR membrane to obtain sterilized clean water by using the water production pump. Part of the clean water is returned to the PD / A tank to provide NH4 for AnAOB. + -N and NO2 - -N thus removes the remaining NH4 + -N is removed, while the other part of the clean water enters the reuse tank 65. The MLVSS in the short-cut nitrification tank 64 should be 2000-4500 mg / L; the aeration fan is linked with DO. When continuous aeration is used, DO should be 0-0.3 mg / L. When intermittent aeration mode is used, the aeration-stop ratio should be 0.2-1.5. The clean water production mode of MBR operation is intermittent mode, with water produced at high liquid level (1.0m above the membrane module) and stopped at low liquid level (0.15m above the membrane module). NO2 in the produced water - -N and NH4 + -N ratio is 1.0~1.5, the water production flux during operation should be 10~20L / (㎡·h), the backwash is automatic backwash cycle 20~30min / 3~10d, the online cleaning agent is sodium hypochlorite, the concentration is 150~200mg / L, the cleaning frequency depends on the operation, generally 15~30d; the water production return ratio (clean water returns to the denitrification tank 62) should be 100%~400%.

[0051] The reuse tank 65 is connected after the short-range nitrification tank 64 and receives the regeneration liquid. At the same time, the automatic control program replenishes clean water to the reuse tank to make up for the water loss (such as evaporation, etc.) during the deodorization and recycling process.

[0052] The absorption and oxidation process of ammonia by the two-stage washing component realizes the removal and conversion of ammonia in the gas phase, but it produces washing liquid wastewater with a low carbon-nitrogen ratio (COD / TN, C / N). The operating cost of regenerating this wastewater using the traditional nitrification and denitrification process is high and unacceptable. Therefore, the second part of the present invention is a washing liquid regeneration system, which is a process based on anaerobic ammonia oxidation denitrification technology to convert nitrogen in the washing liquid into nitrogen gas to achieve the purpose of denitrification (converting liquid nitrogen into gaseous nitrogen). The specific implementation principle is: the nitrogen in the washing liquid exists mainly in the form of NH4 + -N, NO3 - -N is the main denitrification pathway, so by controlling the appropriate conditions, a denitrification pathway based on short-term denitrification anaerobic ammonium oxidation and assisted by denitrification can occur in the denitrification tank 62 (PD / A tank). - -N and NO2 - -N is reduced to nitrogen gas, and short-range denitrifying bacteria can convert NO3 in the washing liquid into - -N is reduced to NO2 - -N, and then anaerobic ammonium oxidizing bacteria (AnAOB) with NO2 - -N is an electron acceptor that converts NH4 + -N is converted into nitrogen, and about 0.11×(NO2 - -N+NH4 + -N)NO3 - -N, completing the first PD / A process; further, the short-range denitrifying bacteria continue to convert the NO3 produced in the anaerobic ammonium oxidation process into - -N is reduced to NO2 - -N, and then AnAOB with NO2 - -N is an electron acceptor that converts NH4 + -N is converted into nitrogen, and about 0.11×(NO2 - -N+NH4 + -N)NO3 - -N, complete the second PD / A process, reciprocating cycle. In addition, the NO2 in the regeneration liquid returned from the short-range nitrification tank 64 (MBR membrane tank) - -N and NH4 + -N is further consumed by AnAOB in the PD / A pool, and the 0.11×(NO2 - -N+NH4 + -N)NO3 - -N then enters the PD / A process and the cycle repeats. It can be seen that the regeneration of the washing liquid is completed through the synergy of the PD / A + MBR system.

[0053] exist Figure 1In a preferred embodiment shown, the washing water used by the first water curtain wall 21 comes from the first circulation pool 22; the washing water used by the second water curtain wall 31 comes from the second circulation pool 32, thereby realizing the recycling of water used in the entire system.

[0054] exist Figure 1 In a preferred embodiment shown, a hydrolysis acidification tank 7 is also included.

[0055] Among them, the hydrolysis and acidification tank 7 is connected between the sewage source 4 and the first sedimentation tank 5. The hydrolysis and acidification tank 7 decomposes the macromolecular organic matter in the sewage into small molecular substances and converts the hydrolysis products into volatile fatty acids. In general, the process can be divided into two stages, the hydrolysis stage and the acidification stage. (1) Hydrolysis stage: Under anaerobic conditions, microorganisms decompose macromolecular organic matter (such as protein, starch, cellulose, etc.) into small molecular organic matter (such as fatty acids, monosaccharides, amino acids, etc.) through extracellular enzymes or fixed enzymes, making them soluble substances and forming hydrolysis products; (2) Acidification stage: Further, the hydrolysis products are converted into volatile fatty acids (such as acetic acid, propionic acid, etc.) under the action of acidifying bacteria, and a small amount of carbon dioxide and hydrogen are produced at the same time. The COD of pig farm sewage is 10,000-20,000 mg / L, and NH4 + -N is 500~750mg / L, NO2 - -N≈0mg / L, NO3 - -N is 0-3 mg / L, TP is 40-120 mg / L, TN is 550-800 mg / L, pH is 7.0-7.8, alkalinity is 2500-3500 mg / L (calculated as CaCO3), and rich trace elements; the reaction pH of the hydrolysis acidification tank 7 is preferably 5.5-6.5, the reaction temperature is preferably 20℃-35℃, the rising flow rate is preferably 0.5-2.0 m / h, MLVSS is preferably 2000-4500 mg / L, HRT is 4.0-12.0 h, DO is preferably <0.2 mg / L, and the organic load (OLR) is 1.0-5.0 kgCOD / (m 3 d) The dissolved COD (SCOD) in the effluent of the hydrolysis and acidification tank 7 should be between 6000 and 15000 mg / L, and the VFA concentration should not be lower than 1000 mg / L.

[0056] In the above embodiment, when clean water is used as the absorbent, the main characteristics of the washing liquid water quality are: COD content is 50-200 mg / L, NH4 + -N is 350~600mg / L, NO2 -The water quality is characterized by a nitrogen-N content of 400-700 mg / L, a pH of 4.8-6.5, and a DO of 4.0-6.5 mg / L, with virtually no phosphorus or trace elements. These water characteristics make it difficult to achieve the conditions required for the PD / A process. Therefore, achieving this denitrification process requires providing the biochemical system with an available carbon source, trace elements, a phosphorus source, an inorganic carbon source, an appropriate pH (6.7-8.0), and an oxygen-deficient environment. The present invention achieves the above-mentioned needs by introducing high-concentration sewage discharged from pig farms after solid-liquid separation into the washing liquid. The specific implementation principle is: (1) Pig farm sewage contains rich carbon sources, phosphorus sources, trace elements, alkalinity, etc., which can provide suitable external conditions for the microbial process involved in the present invention; (2) The hydrolysis and acidification tank 7 can convert the macromolecular organic matter in the pig farm sewage into short-chain easily utilized organic matter (such as volatile fatty acids, VFA), providing an available carbon source for short-range denitrifying bacteria and full-range denitrifying bacteria; (3) Adding an appropriate amount of fine lime and PAM reagents in the first sedimentation tank 5 to remove suspended solids in the effluent of the hydrolysis and acidification tank, while improving the mixing efficiency. pH of the mixed liquid; (4) By controlling the addition ratio of piggery wastewater, water homogenization can be achieved in the regulating tank 61. The reasons are: first, piggery wastewater has a high alkalinity, and the addition of this wastewater can increase the alkalinity of the mixed liquid as a whole; second, the addition of piggery wastewater without dissolved oxygen will introduce a higher concentration of organic matter, which will promote the respiration of aerobic microorganisms and quickly consume the dissolved oxygen in the washing liquid discharged from the two-stage circulation pool, creating anaerobic environmental conditions for the subsequent biochemical system; finally, the appropriate C / N can be adjusted in the regulating tank to meet the carbon source requirements of short-range denitrifying bacteria and full-range denitrifying bacteria, while the denitrification tank can also produce alkalinity. In addition, the MBR aeration tank is a place where AOB converts the remaining NH4 + -N is converted to NO2 - -N, while aerobic heterotrophic bacteria can further degrade part of the COD to ensure the effluent quality. After the sterilized clean water is filtered through the MBR membrane, part of it is returned to the PD / A denitrification tank 62 to provide NH4 for AnAOB + -N and NO2 - -N, and the other part goes into the reuse water pool to replenish the water needed in the two-stage circulation pool, thus achieving an overall closed loop. The sludge generated during the regeneration process is sent to the pig farm sewage treatment station for unified treatment.

[0057] exist Figure 1 In a preferred embodiment shown, an alkaline agent is added during the mixing of sewage and the first washing liquid in the first sedimentation tank 5 to supplement the alkalinity of the first tail water and remove suspended matter, which can provide a suitable pH value for the subsequent operation of the biochemical unit.

[0058] exist Figure 1 In a preferred embodiment shown in FIG, DO in the regulating tank 61 is controlled to be less than 0.2 mg / L, and COD / NO3 in the regulating tank 61 is controlled to be less than 0.2 mg / L.- -N is 2.0 to 4.0. The core purpose of the regulating tank 61 in the present invention is to balance the water quality. An online pH probe, COD, and nitrate nitrogen online monitoring instruments are installed in the regulating tank 61 to monitor the water quality.

[0059] exist Figure 2 In a preferred embodiment shown, a number of filler balls 331 are set in the filler frame 33, and the filler balls 331 are filled with polyurethane sponges and nitrifying bacteria are inoculated on the polyurethane sponges. The filling rate of the filler frame 33 is 20% to 35%, and the filling rate of the filler balls 331 is 30% to 40%. The principle of colonization and enrichment of nitrifying bacteria is as follows: autotrophic nitrifying bacteria are inoculated into the circulating water pool, and carrier fillers including but not limited to polyurethane sponges are added to the circulating water pool, and nitrifying bacteria are gradually colonized and enriched on the carriers of the filler frame in the second-stage water curtain wall and the second-stage circulating water pool; under the condition of poor COD content (50 to 200 mg / L), the acclimated nitrifying bacteria will occupy the dominant ecological niche and proliferate. At this time, the nitrifying bacteria attached to the filler or the second-stage water curtain wall can oxidize the ammonia nitrogen in the liquid phase into nitrate nitrogen, while consuming alkalinity (producing H + ) to maintain the weakly acidic environment of the washing liquid in the second-stage circulating water pool. The principle formula is:

[0060] NH4 + Oxidation:

[0061] NH4 + +1.238O2+0.04HCO3 - +0.161CO2→0.96NO2 - +0.04C5H7NO2+0.919H2O+1.919H + ;

[0062] NO2 - Oxidation:

[0063] NO2 - +0.01NH4 + +0.45O2+0.01HCO3 - +0.01H2O+0.04CO2→NO3 - +0.01C5H7NO2.

[0064] The nitrifying bacteria cultivation process is mainly divided into two stages:

[0065] The first stage is the colonization stage of nitrifying bacteria: First, the nitrifying bacteria purchased from the market and inorganic nutrients (carbon source, nitrogen source, phosphorus source, etc.) are placed in a 1m 3The volume container is aerated (DO ≥ 2.0 mg / L) for 2 to 4 hours for activation, and then it is inoculated into the second circulation pool 32. Then, the pH of the washing liquid is controlled to 7.0 to 8.0 by adding sodium bicarbonate and a small amount of inorganic salt nutrients is added. The pig house exhaust fan is turned on and the circulating water pump spray system is turned on for continuous spraying for 7 to 10 days. Secondly, the liquid level in the second circulation pool 32 is regularly checked during the operation phase (the washing liquid is not discharged to the outside), and clean water is added in an appropriate amount to maintain a constant liquid level in the second circulation pool 32. Thirdly, the concentrations of DO, ammonia nitrogen, nitrite and nitric nitrogen in the second washing liquid are tested daily. Finally, the NO3 in the nitrogen in the second washing liquid is used to determine the concentration of the washing liquid. - The -N mass concentration percentage is used as the basis for determining the establishment of the nitrification process. When its proportion is greater than 30% to 40%, the biological oxidation process of ammonia is gradually established. Otherwise, the above steps need to be repeated.

[0066] The second stage is the domestication and enrichment stage of nitrifying bacteria: First, drain all the second washing liquid in the second circulation pool 32, and add fresh tap water again to the same liquid level; secondly, turn on the pig house exhaust fan, turn on the water pump in the second circulation pool 32 to start the spraying system, complete the ammonia absorption process, and regularly add an appropriate amount of clean water (containing a small amount of nutrients) to maintain the second circulation pool 32 liquid level unchanged, and the pH value gradually decreases from neutral to weak acid, and runs continuously for 10 to 15 days. Finally, the changes in pH, ammonia nitrogen, nitrite, and nitric nitrogen indicators in the second washing liquid are tested daily. When the pH is weakly acidic and NO3 - When the -N mass concentration is greater than 50%, it indicates that the acclimation and enrichment of nitrifying bacteria has gradually stabilized. Otherwise, the above steps need to be repeated. After entering the normal operation stage, the addition of nutrients is stopped. The nutrients for nitrifying bacteria are provided by the regenerated washing liquid. The absorption of ammonia continues to follow the technical parameters of the nitrifying bacteria enrichment stage.

[0067] exist Figure 1 In a preferred embodiment shown, the volume of the recycling tank 65 is greater than the sum of the volumes of the first circulation tank 22 and the second circulation tank 32. The first circulation tank 22 or the second circulation tank 32 has a preset water level. When the water level in the first circulation tank 22 or the second circulation tank 32 falls below the preset level, the recycling tank 65 supplies regeneration liquid to the first circulation tank 22 or the second circulation tank 32. When the water level in the first circulation tank 22 or the second circulation tank 32 reaches the preset level, the recycling tank 65 stops supplying regeneration liquid to the first circulation tank 22 or the second circulation tank 32. This control method fully utilizes the circulating regeneration liquid.

[0068] The present invention is based on the odor emission of a certain scale farm in Guangdong with a volume of 1.2 million m 3 / h is an implementation case, and ammonia concentrations at the air inlet and outlet are detected using a portable ammonia detection instrument. The average ammonia removal efficiency of the second water curtain wall 31 is 84.5±2.9% (e.g. Figure 3The pH value can be stably maintained at a weakly acidic condition (5.3 ± 0.42) (as shown in Figure 4 As shown), the nitrogen in the washing liquid is mainly NH4 + -N and NO3 - -N form, NO3 - -N and NH4 + -N concentration mass ratio is 1.2±0.1. At the same time, the performance of the washing liquid regeneration system for nitrogen removal in a typical cycle (such as Figure 5 The data (shown) were tested and the results showed that the average removal efficiency of the regeneration system for total nitrogen was 93.1±5.1%.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for treating ammonia odor and regenerating washing liquid in livestock and poultry farms, characterized in that: include: A first washing component (2) is connected to the odor source (1) of the farm, and the first washing component (2) removes feed dust from the odor to form a first washing liquid; a second washing component (3) connected after the first washing component (2), wherein the second washing component (3) absorbs ammonia in the odor and transfers the ammonia to a liquid phase, and the second washing component (3) oxidizes the ammonia in the liquid phase to form a second washing liquid; a first sedimentation tank (5), connected after the first washing component (2) and connected to the sewage source (4) of the farm, wherein the first sedimentation tank (5) simultaneously receives the first washing liquid and the sewage source (4) for sedimentation to form first tail water; a circulation component (6) connected after the first sedimentation tank (5) and connected to the outlet water of the second washing component (3); the circulation component (6) mixes the second washing liquid and the first tail water to form the second tail water; the circulation component (6) performs denitrification, short-range nitrification and mud-water separation on the second tail water to form a regeneration liquid; the regeneration liquid is transported to the first washing component (2) and the second washing component (3) and used to wash the odor; The first washing component (2) comprises, A first water curtain wall (21) is arranged facing the flow direction of the odor, and the first water curtain wall (21) washes away feed dust in the odor by spraying a water curtain; a first circulation pool (22), disposed below the first water curtain wall (21) and receiving washing water falling from the first water curtain wall (21) to form a first washing liquid; The second washing component (3) comprises, The second water curtain wall (31) is also arranged facing the flow direction of the odor, and the second water curtain wall (31) absorbs ammonia in the odor by spraying a water curtain; a second circulation pool (32), disposed below the second water curtain wall (31) and receiving washing water falling from the second water curtain wall (31); A filler frame (33) is provided in the second circulation pool (32), wherein fillers with attached nitrifying bacteria are provided in the filler frame (33), and the nitrifying bacteria oxidize ammonia in the washing water to form a second washing liquid; A plurality of filler balls (331) are arranged in the filler frame (33), the filler balls (331) are filled with polyurethane sponge and nitrifying bacteria are attached to the polyurethane sponge, the filling rate of the filler frame (33) is 20% to 35%, and the filling rate of the filler balls (331) is 30% to 40%.

2. The device for treating ammonia odor and regenerating washing liquid in livestock and poultry farms according to claim 1, characterized in that: The circulation component (6) comprises, A regulating tank (61) is connected after the first sedimentation tank (5), wherein the first tail water in the first sedimentation tank (5) flows by gravity into the regulating tank (61), and the second washing liquid of the second washing component (3) is drained and injected into the regulating tank (61); a denitrification tank (62), connected after the regulating tank (61) and performing denitrification on the second tail water; A second sedimentation tank (63) is connected after the denitrification tank (62) and performs mud-water separation on the second tail water after denitrification; A short-cut nitrification tank (64) is connected to the second sedimentation tank (63) to oxidize the remaining ammonia nitrogen in the second tail water into nitrite and perform mud-water separation again to obtain regenerated liquid; The reuse tank (65) is connected after the short-cut nitrification tank (64) and receives the regeneration liquid, and replenishes the reuse tank (65) with clean water.

3. The device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms according to claim 1, characterized in that: The washing water used by the first water curtain wall (21) comes from the first circulation pool (22); the washing water used by the second water curtain wall (31) comes from the second circulation pool (32).

4. The device for treating ammonia odor and regenerating washing liquid in livestock and poultry farms according to claim 2, characterized in that: Also includes: The hydrolysis and acidification tank (7) is connected between the sewage source (4) and the first sedimentation tank (5). The hydrolysis and acidification tank (7) decomposes the macromolecular organic matter in the sewage into small molecular substances and converts the hydrolysis products into volatile fatty acids.

5. The device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms according to claim 4, characterized in that: During the mixing of the sewage and the first washing liquid in the first sedimentation tank (5), an alkaline agent is added to supplement the alkalinity of the first tail water.

6. The device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms according to claim 2, characterized in that: Control the DO in the regulating tank (61) to be less than 0.2 mg / L, and control the COD / NO3 in the regulating tank (61) - -N is 2.0~4.

0.

7. The device for treating ammonia-containing odor and regenerating washing liquid in livestock and poultry farms according to claim 2, characterized in that: The volume of the reuse pool (65) is greater than the sum of the volumes of the first circulation pool (22) and the second circulation pool (32), and the first circulation pool (22) or the second circulation pool (32) has a preset water level; When the water level in the first circulation pool (22) or the second circulation pool (32) is lower than a preset water level, the reuse pool (65) transports regeneration liquid to the first circulation pool (22) or the second circulation pool (32); When the water level in the first circulation pool (22) or the second circulation pool (32) reaches a preset water level, the reuse pool (65) stops transporting the regeneration liquid to the first circulation pool (22) or the second circulation pool (32).

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