Method and device for simultaneous denitrification and deodorization of livestock wastewater

Abstract

The present application belongs to wastewater treatment technology, and particularly relates to a method and device for simultaneously removing nitrogen and odor from livestock wastewater. The method provided by the present application places a hollow fiber membrane with attached activated sludge and an anaerobic ammonia oxidation module containing granular sludge in a biofilm reactor to obtain a denitrification and odor removal system to be acclimated; the activated sludge comprises nitrifying bacteria and first odor removal microorganisms; the granular sludge comprises anaerobic ammonia oxidation bacteria and second odor removal microorganisms; ammonium salt medium is added to the denitrification and odor removal system to be acclimated for acclimation treatment to obtain a denitrification and odor removal system; and wastewater to be treated is injected into the denitrification and odor removal system for denitrification and odor removal treatment under bubble-free aeration conditions. The method for simultaneously removing nitrogen and odor from livestock wastewater can control the generation of odor from the source, and can achieve efficient removal of odor while denitrifying livestock wastewater.

Description

Technical Field

[0001] This invention pertains to wastewater treatment technology, specifically to a method and apparatus for simultaneous denitrification and deodorization of livestock wastewater. Background Technology

[0002] Livestock farming is an important part of the agricultural economy, but the wastewater pollution it generates is becoming increasingly serious. Livestock wastewater not only has extremely high concentrations of ammonia nitrogen (NH3-N) and chemical oxygen demand (COD), but also contains large amounts of organic matter, nitrogen compounds, and sulfates. Under anaerobic conditions, it easily produces complex malodorous substances such as hydrogen sulfide (H2S), methanethiol (CH3SH), ammonia (NH3), volatile fatty acids (VFAs), indole, and skatole, causing serious pollution to the surrounding atmospheric environment and affecting the green and sustainable development of livestock farming.

[0003] Generally, odor control technologies for large-scale livestock farms are mainly divided into odor source reduction technologies, odor process control technologies, and odor end-of-pipe control technologies. Related studies show that odor emissions during manure storage and application account for 65% of the total emissions from livestock farms, which are closely related to odor source reduction and process control technologies. However, under the current large-scale farming model, odor control in livestock farms mainly relies on end-of-pipe control technologies, including physical methods (adsorption, dilution diffusion, and filtration), chemical methods (absorption, oxidation, and plasma methods), and biological methods (microbial packing). Furthermore, existing deodorization technologies typically perform deodorization after nitrogen removal from livestock wastewater, lacking technologies that can simultaneously, efficiently, and stably remove multiple malodorous substances during the nitrogen removal process. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for simultaneous denitrification and deodorization of livestock wastewater. The method for simultaneous denitrification and deodorization of livestock wastewater provided by this invention can control odor generation at the source and achieve efficient odor removal while simultaneously denitrifying the livestock wastewater.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for simultaneous denitrification and deodorization of livestock wastewater includes the following steps: Hollow fiber membranes inoculated with activated sludge and anaerobic ammonia oxidation modules containing granular sludge are placed in a biofilm reactor to obtain a denitrification and deodorization system to be acclimated; the activated sludge includes nitrifying bacteria and a first deodorizing microorganism; the granular sludge includes anaerobic ammonia oxidizing bacteria and a second deodorizing microorganism; Ammonium salt culture medium was added to the denitrification and deodorization system to be acclimated, and acclimation treatment was carried out to obtain the denitrification and deodorization system; Livestock wastewater is injected into the denitrification and deodorization system, and denitrification and deodorization are carried out under bubble-free aeration conditions on the hollow fiber membrane.

[0006] Preferably, the nitrifying bacteria in the activated sludge include Nitrosomonas, and the first deodorizing microorganisms include Microbes spp., Pseudomonas spp., Luteinobacter spp., and Thermomonas spp.

[0007] Preferably, the relative abundance of *Nitrosomonas* in the activated sludge is 3.8-9%, the relative abundance of *Microbes* is 0.4-0.6%, the relative abundance of *Pseudomonas* is 1.1-1.3%, the relative abundance of *Gastrodinium* is 2.3-6%, and the relative abundance of *Thermomonas* is 4.2-5.2%.

[0008] Preferably, the anaerobic ammonia-oxidizing bacteria in the granular sludge include the Brocadia candidate genus, and the second deodorizing microorganisms include Thermomonas, Xanthomonas, Rhodotorula, Pseudomonas, and Microbes.

[0009] Preferably, the relative abundance of Brocadia candidate genera in the granular sludge is 7-36.6%, the relative abundance of Thermomonas is 0.5-4.2%, the relative abundance of Xanthomonas is 0.1-2.5%, the relative abundance of Rhodotorula is 0.2-1.4%, the relative abundance of Pseudomonas is 0.4-2%, and the relative abundance of Microbes is 0.2-1%.

[0010] Preferably, the ammonium salt culture medium includes NH4Cl, KHCO3, KH2PO4, acidic trace element solution and alkaline trace element solution; The ammonium salt culture medium has an ammonia nitrogen concentration of 180-200 mg / L and a pH value of 6.5-7.5.

[0011] Preferably, the pH value of the denitrification and deodorization system to be acclimated is 6.5~7.5; the acclimation treatment temperature is 11~35℃, the time is >21 days, and the inflow rate of the ammonium salt culture medium is 0.09~0.27mL / min.

[0012] Preferably, bubble-free aeration of the hollow fiber membrane includes introducing oxygen into the hollow fiber membrane, wherein the oxygen introduction rate is 0.08~0.09 mol·e - ·eq -1 ·d -1 The pressure of the non-foaming aeration is 0.15~0.19MPa; the concentration of ammonia nitrogen in the purified water obtained by the denitrification and deodorization treatment is 1.4~4.1mg / L, and the total nitrogen removal rate is 95.2~98.6%.

[0013] This invention provides a device for simultaneous denitrification and deodorization of livestock wastewater, comprising an inlet tank, a biofilm reactor, and an outlet tank connected in sequence. The biofilm reactor is equipped with a hollow fiber membrane and an anaerobic ammonia oxidation module, and the hollow fiber membrane is connected to an oxygen cylinder.

[0014] Preferably, the device further includes a magnetic stirrer and a water inlet pump; the water inlet pump is connected to the water inlet tank and the biofilm reactor respectively, and the biofilm reactor is located on the magnetic stirrer.

[0015] This invention utilizes a biofilm reactor inoculated with denitrifying bacteria and deodorizing microorganisms to create a denitrification and deodorization system capable of highly efficient denitrification while simultaneously degrading multiple malodorous substances in situ. Specifically, nitrifying bacteria oxidize ammonia nitrogen in livestock wastewater to nitrite, and then anaerobic ammonia-oxidizing bacteria react the generated nitrite with the ammonia nitrogen in the wastewater to produce nitrogen gas. This invention employs both aerobic and anaerobic deodorizing microorganisms to synergistically degrade malodorous substances (ammonia, sulfides, and volatile fatty acids).

[0016] This invention provides a culture medium containing ammonium salts for acclimatization treatment, which can enrich nitrifying bacteria, anaerobic ammonia-oxidizing bacteria, aerobic deodorizing microorganisms, and anaerobic deodorizing microorganisms, thereby constructing a stable denitrification and deodorization system with a highly active composite bacterial community. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the device for simultaneous denitrification and deodorization of livestock wastewater according to the present invention; Figure 2 This is a graph showing the nitrogen content and chemical oxygen demand of the influent and effluent during the 10-day stabilization period of the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1. Figure 3 This is a line graph showing the total nitrogen removal rate during the 10-day stabilization period of the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1. Figure 4 This is a comparison chart of the concentrations of volatile fatty acids in the influent and effluent water during the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1. Figure 5 This is a graph showing the absolute quantitative abundance of the major bacterial communities in activated sludge and granular sludge. Detailed Implementation

[0018] This invention provides a method for simultaneous denitrification and deodorization of livestock wastewater, comprising the following steps: Hollow fiber membranes inoculated with activated sludge and anaerobic ammonia oxidation modules containing granular sludge are placed in a biofilm reactor to obtain a denitrification and deodorization system to be acclimated; the activated sludge includes nitrifying bacteria and a first deodorizing microorganism; the granular sludge includes anaerobic ammonia oxidizing bacteria and a second deodorizing microorganism; Ammonium salt culture medium was added to the denitrification and deodorization system to be acclimated, and acclimation treatment was carried out to obtain the denitrification and deodorization system; Livestock wastewater is injected into the denitrification and deodorization system, and denitrification and deodorization are carried out under bubble-free aeration conditions on the hollow fiber membrane.

[0019] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0020] This invention places a hollow fiber membrane inoculated with activated sludge and an anaerobic ammonia oxidation module containing granular sludge in a biofilm reactor to obtain a denitrification and deodorization system to be acclimated. The activated sludge includes nitrifying bacteria and a first deodorizing microorganism; the granular sludge includes anaerobic ammonia oxidizing bacteria and a second deodorizing microorganism. In one embodiment of this invention, the nitrifying bacteria in the activated sludge include *Nitrosomonas*, and the first deodorizing microorganisms include *Microphytobacterium*, *Pseudomonas*, *Gastrodinium*, and *Thermomonas*.

[0021] In one embodiment of the present invention, the relative abundance of *Nitrosomonas* in the activated sludge is 3.8-9%, the relative abundance of *Microbes* is 0.4-0.6%, the relative abundance of *Pseudomonas* is 1.1-1.3%, the relative abundance of *Gastrodinium* is 2.3-6%, and the relative abundance of *Thermomonas* is 4.2-5.2%.

[0022] In this invention, the relative abundance of each bacterial group in the activated sludge can be as follows: the relative abundance of Nitromonas is 9%, the relative abundance of Microbes filamentosa is 0.4%, the relative abundance of Pseudomonas is 1.1%, the relative abundance of Gambusa zeylans is 6%, and the relative abundance of Thermomonas is 4.2%; the rest are miscellaneous bacteria that are not part of the culture.

[0023] In one embodiment of the present invention, the anaerobic ammonia-oxidizing bacteria in the granular sludge include the Brocadia candidate genus, and the second deodorizing microorganisms include Thermomonas, Xanthomonas, Rhodotorula, Pseudomonas, and Microbes.

[0024] In one embodiment of the present invention, the relative abundance of Brocadia candidate genera in the granular sludge is 7-36.6%, the relative abundance of Thermomonas is 0.5-4.2%, the relative abundance of Xanthomonas is 0.1-2.5%, the relative abundance of Rhodotorula is 0.2-1.4%, the relative abundance of Pseudomonas is 0.4-2%, and the relative abundance of Microbes is 0.2-1%.

[0025] In this invention, the relative abundance of each bacterial group in the granular sludge can be as follows: the relative abundance of Brocadia candidate genus is 7%, the relative abundance of Thermomonas genus is 1%, the relative abundance of Xanthomonas genus is 2.5%, the relative abundance of Rhodotorula genus is 0.2%, the relative abundance of Pseudomonas genus is 0.4%, and the relative abundance of Microbes genus is 0.4%; the rest are miscellaneous bacteria that are not cultured.

[0026] In one embodiment of the present invention, the hollow fiber membrane was purchased from Suzhou Lisheng Membrane Separation Technology Co., Ltd.; the material is polyvinylidene fluoride (PVDF), the outer diameter is 1.3 mm, the inner diameter is 0.7 mm, it is non-porous, and the length is 45 cm.

[0027] In one embodiment of the present invention, the hollow fiber membrane and the anaerobic ammonia oxidation module can be placed in a biofilm reactor, and there are no requirements on their positions, thus obtaining a denitrification and deodorization system to be domesticated.

[0028] This invention oxidizes ammonia nitrogen in livestock wastewater to nitrite using nitrifying bacteria, and then uses anaerobic ammonia-oxidizing bacteria to react the generated nitrite with the ammonia nitrogen in the wastewater to produce nitrogen gas. The anaerobic ammonia oxidation reaction of this invention does not rely on organic carbon sources, thus avoiding the generation of new odors due to carbon source fermentation. This invention employs a first deodorizing microorganism and a second deodorizing microorganism to synergistically degrade malodorous substances (ammonia, sulfides, and volatile fatty acids).

[0029] This invention involves adding an ammonium salt culture medium to the denitrification and deodorization system to be acclimatized, thereby obtaining the denitrification and deodorization system. In one embodiment of this invention, the ammonium salt culture medium comprises NH4Cl, KHCO3, KH2PO4, an acidic trace element solution, and an alkaline trace element solution; the ammonia nitrogen concentration of the ammonium salt culture medium is 180-200 mg / L, and the pH value is 6.5-7.5.

[0030] In one embodiment of the present invention, the acidic trace element solution comprises: 1-7 mL of 36% HCl solution, 1-2 g of FeCl2·4H2O, 0.1-0.2 g of CoCl2·6H2O, 0.05-0.1 g of MnCl2·4H2O, 10-70 mg of ZnCl2, 1-6 mg of H3BO3, 10-36 mg of Na2MoO4·2H2O, and 10 mg of other trace elements added per liter of deionized water. ~24 mg NiCl2·6H2O and 1~3 mg CuSO4·5H2O; the alkaline trace element solution contains: 0.1~0.5 g NaOH, 1~9 mg Na2SeO3·5H2O, and 1~8 mg Na2WO4·2H2O per liter of deionized water; the concentration of KHCO3 in the ammonium salt culture medium is 2.6 g / L, and the concentration of KH2PO4 is 40 mg / L; NH4Cl provides ammonia nitrogen.

[0031] In one embodiment of the present invention, the acclimation treatment temperature is 11~35℃, more preferably 30±5℃, for ≥21 days, and the influent flow rate of the ammonium salt culture medium is 0.09~0.27mL / min. The acclimation treatment is carried out under stirring conditions, and the stirring rate is 200~300r / min. After acclimation treatment, the ammonia nitrogen concentration in the effluent of the denitrification and deodorization system to be acclimated is <5mg / L, more preferably <2mg / L, and the total nitrogen removal rate is >90%, thus obtaining a denitrification and deodorization system.

[0032] This invention injects livestock wastewater into the denitrification and deodorization system, performing denitrification and deodorization treatment on the hollow fiber membrane under bubble-free aeration conditions. In one embodiment of this invention, the concentration of ammonia nitrogen in the livestock wastewater is 190~210 mg / L, specifically 194.3~200.5 mg / L; in another embodiment, the odorous substances in the livestock wastewater include sulfides, ammonia, and volatile fatty acids; the sulfides include hydrogen sulfide and carbonyl sulfide; and the concentration of the odorous substances in the livestock wastewater is 0.43~0.5 mg / m³. 3 .

[0033] In one embodiment of the present invention, in the initial stage of the denitrification and deodorization treatment, livestock wastewater is mixed and diluted with water to obtain wastewater to be treated, and the volume percentage of livestock wastewater injected into the wastewater to be treated is 25%; the denitrification and deodorization treatment time is >21 days, specifically 30 days, the concentration of ammonia nitrogen in the effluent is <7mg / L, and the ammonia nitrogen removal rate in the effluent is >90%; in subsequent denitrification and deodorization treatments, the volume percentage of livestock wastewater in the wastewater to be treated is gradually increased from 25% to 50%, 80%, and 100%; specifically, this can be achieved by: diluting the livestock wastewater in the wastewater to be treated with water to obtain the desired wastewater. The volume percentage of water in the wastewater to be treated was increased from 25% to 50%, and denitrification and deodorization treatment was carried out continuously for 30 days under non-foaming aeration conditions, with an effluent ammonia nitrogen removal rate >90%. Similarly, the volume percentage of livestock wastewater in the wastewater to be treated was increased from 50% to 80%, and denitrification and deodorization treatment was carried out continuously for 30 days under non-foaming aeration conditions, with an effluent ammonia nitrogen removal rate >90%. Furthermore, the volume percentage of livestock wastewater in the wastewater to be treated was increased from 80% to 100%, and denitrification and deodorization treatment was carried out continuously for 30 days under non-foaming aeration conditions, with an effluent ammonia nitrogen removal rate >90%. This invention limits the initial volume percentage of livestock wastewater in the wastewater to be treated to 25%, and then gradually increases the volume percentage to avoid the destruction of bacterial activity by high concentrations of ammonia nitrogen and odorous substances.

[0034] In one embodiment of the present invention, bubble-free aeration of the hollow fiber membrane includes introducing oxygen into the hollow fiber membrane, wherein the amount of oxygen introduced is 0.08~0.09 mol·e - ·eq -1 ·d -1The pressure of the bubble-free aeration is 0.15~0.19 MPa; the concentration of ammonia nitrogen in the purified water obtained from the denitrification and deodorization treatment is 1.4~4.1 mg / L, and the total nitrogen removal rate is 95.2~98.6%. Existing technologies use continuous bubbling aeration with aeration discs, which makes it easier for odorous substances in the wastewater to be treated to be released into the air. This invention uses bubble-free aeration to efficiently supply oxygen and complete short-cut nitrification, significantly reducing ammonia nitrogen while avoiding odor escape caused by bubble agitation. The odor is not easily diffused into the air, keeping it within the biofilm reactor, which is beneficial for deodorization.

[0035] This invention provides a device for simultaneous denitrification and deodorization of livestock wastewater, comprising an inlet tank, a biofilm reactor, and an outlet tank connected in sequence. The biofilm reactor is equipped with a hollow fiber membrane and an anaerobic ammonia oxidation module, and the hollow fiber membrane is connected to an oxygen cylinder.

[0036] In one embodiment of the present invention, the device further includes a magnetic stirrer and a water inlet pump; the water inlet pump is connected to the water inlet tank and the biofilm reactor respectively, and the biofilm reactor is located on the magnetic stirrer; the water inlet pump is connected to the bottom inlet of the biofilm reactor, and the water outlet tank is connected to the top outlet of the biofilm reactor.

[0037] This invention uses an inlet pump to pump the wastewater to be treated from the inlet tank into the biofilm reactor. The inlet pump is connected to the bottom inlet of the biofilm reactor through a pipe. The wastewater to be treated enters from the bottom of the biofilm reactor, and the odor is not easily diffused into the air, which is beneficial for deodorization while treating wastewater.

[0038] The present invention places the biofilm reactor on a magnetic stirrer, and the denitrification and deodorization treatment is carried out under stirring conditions by magnetic stirring, which promotes the contact between ammonia nitrogen and odorous substances in the wastewater to be treated and the hollow fiber membrane and anaerobic ammonia oxidation module.

[0039] This invention connects the oxygen cylinder to the hollow fiber membrane in the biofilm reactor, providing oxygen to the hollow fiber membrane so that the nitrifying bacteria and aerobic deodorizing microorganisms on the hollow fiber membrane can achieve denitrification and deodorization under oxygen conditions.

[0040] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments thereof. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] Figure 1This is a schematic diagram of the device for simultaneous denitrification and deodorization of livestock wastewater according to the present invention. The device includes an inlet tank, an inlet pump, a biofilm reactor, and an outlet tank connected in sequence. The biofilm reactor is equipped with a hollow fiber membrane and an anaerobic ammonia oxidation module, and the hollow fiber membrane is connected to an oxygen cylinder. The inlet pump is connected to both the inlet tank and the biofilm reactor, and the biofilm reactor is located on a magnetic stirrer. Embodiment 1 of the present invention uses... Figure 1 The device simultaneously denitrifies and deodorizes livestock wastewater.

[0042] The activated sludge of this invention was obtained from the aerobic pond of Shanghai Fengxian Haiwan Livestock Farm; the granular sludge was obtained from the Taobao store of Jia Yi Environmental Protection. This invention involves a first acclimatization treatment of the activated sludge and granular sludge to obtain first activated sludge and first granular sludge. The steps of the first acclimatization treatment are described in Example 1 of patent CN121292659A.

[0043] Example 1 (1) The hollow fiber membrane and the anaerobic ammonia oxidizing bacteria module are set in the biofilm reactor; the hollow fiber membrane (purchased from Suzhou Lisheng Membrane Separation Technology Co., Ltd.; material is PVDF, outer diameter is 1.3 mm, inner diameter is 0.7 mm, non-porous, length is 45 cm) in the biofilm reactor is inoculated with the first activated sludge, the first activated sludge includes nitrifying bacteria and the first deodorizing microorganism, specifically: the relative abundance of Nitrosomonas is 9%, the relative abundance of Microbes filamentosa is 0.4%, the relative abundance of Pseudomonas is 1.1%, the relative abundance of Gambusa zearalensis is 6%, the relative abundance of Thermomonas is 4.2%; the rest are miscellaneous bacteria that are not culture objects.

[0044] (2) Add the first granular sludge to the anaerobic ammonia oxidizing bacteria module in the biofilm reactor. The first granular sludge includes anaerobic ammonia oxidizing bacteria and anaerobic deodorizing microorganisms, specifically: the relative abundance of Brocadia candidate genus is 7%, the relative abundance of Thermomonas genus is 1%, the relative abundance of Xanthomonas genus is 2.5%, the relative abundance of Rhodotorula genus is 0.2%, the relative abundance of Pseudomonas genus is 0.4%, and the relative abundance of Microbes genus is 0.4%; the rest are miscellaneous bacteria that are not culture objects.

[0045] (3) Add NH4Cl, KHCO3, KH2PO4, 1 mL / L acidic trace element solution and 1 mL / L alkaline trace element solution to deionized water to obtain ammonium salt culture medium. The concentration of ammonia nitrogen in the ammonium salt culture medium is 200 mg / L, the concentration of KHCO3 is 2.6 g / L, the concentration of KH2PO4 is 40 mg / L, and the pH value is 6.5~7.5.

[0046] (4) Oxygen is introduced into the hollow fiber membrane, and denitrification and deodorization treatment is carried out for 30 days under bubble-free aeration conditions. The oxygen introduction rate is 0.09 mol·e - ·eq -1 ·d -1 The pressure of the non-foaming aeration is 0.15 MPa; the ammonium salt culture medium is injected into the biofilm reactor at a flow rate of 0.27 mL / min; the magnetic stirrer is set to 200 r / min and acclimatized at 30±5℃ for 21 consecutive days to achieve an ammonia nitrogen concentration of <2 mg / L and a total nitrogen removal rate of >90%, thus obtaining a denitrification and deodorization system.

[0047] (5) The livestock wastewater is mixed and diluted with tap water to obtain a volume percentage of livestock wastewater in the wastewater to be treated of 25%; oxygen is introduced into the hollow fiber membrane for denitrification and deodorization under bubble-free aeration conditions, and the oxygen introduction rate is 0.09 mol·e - ·eq -1 ·d -1 The pressure of the non-foaming aeration is 0.19 MPa. The wastewater to be treated is injected into the denitrification and deodorization system using an inlet pump and operated continuously for 30 days, resulting in an ammonia nitrogen concentration in the effluent of <7 mg / L and an ammonia nitrogen removal rate of >90%. The volume percentage of livestock wastewater in the wastewater to be treated is gradually increased from 25% to 50%, and denitrification and deodorization are carried out continuously for 30 days under non-foaming aeration conditions, achieving an ammonia nitrogen removal rate of >90%. The volume percentage of livestock wastewater in the wastewater to be treated is increased from 50% to 80%, and denitrification and deodorization are carried out continuously for 30 days under non-foaming aeration conditions, achieving an ammonia nitrogen removal rate of >90%. The volume percentage of livestock wastewater in the wastewater to be treated is increased from 80% to 100%, and denitrification and deodorization are carried out continuously for 30 days under non-foaming aeration conditions, achieving an ammonia nitrogen removal rate of >90%.

[0048] Test Example 1 During the simultaneous denitrification and deodorization treatment of livestock wastewater, when the volume percentage of livestock wastewater in the wastewater to be treated is 100%, the nitrogen content and chemical oxygen demand of the influent and effluent are detected during the 10-day stabilization period.

[0049] Figure 2 This is a graph showing the nitrogen content and chemical oxygen demand of the influent and effluent during the 10-day stabilization period of the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1. Figure 3 This is a line graph showing the total nitrogen removal rate during the 10-day stabilization period of the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1.

[0050] according to Figure 2 and Figure 3It can be seen that the concentration of ammonia nitrogen in the influent is 194.3~200.5 mg / L, and the concentration of ammonia nitrogen in the effluent decreases to 1.4~4.1 mg / L; the concentration of nitrite nitrogen is 0.2~1.4 mg / L; and the concentration of nitrate nitrogen is 2.7~8.1 mg / L. The chemical oxygen demand (COD) in the influent is 250~343 mg / L, and the COD in the effluent is 170~232 mg / L. The total nitrogen removal rate in the effluent is 95.2~98.6%.

[0051] Test Example 2 When the volume percentage of livestock wastewater in the wastewater to be treated is 100%, influent and final effluent samples are collected simultaneously. Gas chromatography (GC) is used to quantitatively analyze the concentration of volatile fatty acids (VFAs) in the water samples, and the results are as follows: Figure 4 As shown.

[0052] Figure 4 This is a comparison chart of the concentrations of volatile fatty acids in the influent and effluent water during the simultaneous denitrification and deodorization treatment of livestock wastewater in Example 1. According to... Figure 4 It can be seen that the concentrations of acetic acid in the influent are 6.4 μg / mL, propionic acid is 4.1 μg / mL, and total VFA is 14.4 μg / mL; the concentrations of acetic acid in the effluent are 1.7 μg / mL, propionic acid is 1.1 μg / mL, and total VFA is 6.2 μg / mL. By calculating the removal rates of total VFA in the influent and effluent, it can be seen that the simultaneous denitrification and deodorization method provided by this invention can efficiently degrade volatile fatty acids.

[0053] Test Example 3 A fixed volume of headspace gas was collected directly above the liquid surface in the inlet and outlet water tanks using a gas sampling pump and sampling bags. The concentrations of sulfur compounds and ammonia were detected using gas chromatography. The concentrations of each target odor substance in the inlet and outlet headspace gas were compared, and the results are shown in Table 1.

[0054] Table 1 Concentrations of various odorous substances in the inlet and outlet headspace gases.

[0055] As shown in Table 1, the carbonyl sulfur content in the top air of the outlet water is significantly reduced, while the hydrogen sulfide content is higher than that of the top air of the inlet water, possibly because some of the carbonyl sulfur is converted into hydrogen sulfide.

[0056] Test Example 4 Figure 5 This is a graph showing the absolute quantitative abundance of the major bacterial communities in activated sludge and granular sludge. Figure 5 This indicates that the main deodorizing bacteria are Microbes spp., Pseudomonas spp., Rhodotorula spp., Xanthomonas spp., and Thermomonas spp., which can degrade VFA and sulfides, and also deal with acidic odors and typical malodors.

[0057] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for simultaneous denitrification and deodorization of livestock wastewater, comprising the following steps: Hollow fiber membranes inoculated with activated sludge and anaerobic ammonia oxidation modules containing granular sludge are placed in a biofilm reactor to obtain a denitrification and deodorization system to be acclimated; the activated sludge includes nitrifying bacteria and a first deodorizing microorganism; the granular sludge includes anaerobic ammonia oxidizing bacteria and a second deodorizing microorganism; Ammonium salt culture medium was added to the denitrification and deodorization system to be acclimated, and acclimation treatment was carried out to obtain the denitrification and deodorization system; Livestock wastewater is injected into the denitrification and deodorization system, and denitrification and deodorization are carried out under bubble-free aeration conditions on the hollow fiber membrane.

2. The method according to claim 1, characterized in that, The nitrifying bacteria in the activated sludge include Nitrosomonas, and the first deodorizing microorganisms include Microbes filamentosa, Pseudomonas, Luteinella, and Thermomonas.

3. The method according to claim 2, characterized in that, The relative abundance of *Nitrosomonas* in the activated sludge was 3.8–9%, *Microbes* was 0.4–0.6%, *Pseudomonas* was 1.1–1.3%, *Gastrodinium* was 2.3–6%, and *Thermomonas* was 4.2–5.2%.

4. The method according to claim 1, characterized in that, The anaerobic ammonia-oxidizing bacteria in the granular sludge include the Brocadia candidate genus, and the second deodorizing microorganisms include Thermomonas, Xanthomonas, Rhodotorula, Pseudomonas, and Microbes.

5. The method according to claim 4, characterized in that, The relative abundance of Brocadia candidate genera in the granular sludge was 7–36.6%, that of Thermomonas was 0.5–4.2%, that of Xanthomonas was 0.1–2.5%, that of Rhodotorula was 0.2–1.4%, that of Pseudomonas was 0.4–2%, and that of Microbes was 0.2–1%.

6. The method according to claim 1, characterized in that, The ammonium salt culture medium includes NH4Cl, KHCO3, KH2PO4, acidic trace element solution and alkaline trace element solution; The ammonium salt culture medium has an ammonia nitrogen concentration of 180-200 mg / L and a pH value of 6.5-7.

5.

7. The method according to claim 1, characterized in that, The pH value of the denitrification and deodorization system to be acclimated is 6.5~7.5; the acclimation treatment temperature is 11~35℃, the time is >21 days, and the inflow rate of the ammonium salt culture medium is 0.09~0.27mL / min.

8. The method according to claim 1, characterized in that, The bubble-free aeration of the hollow fiber membrane includes introducing oxygen into the hollow fiber membrane at a rate of 0.08~0.09 mol·e⁻¹. - ·eq -1 ·d -1 The pressure of the non-foaming aeration is 0.15~0.19MPa; the concentration of ammonia nitrogen in the purified water obtained by the denitrification and deodorization treatment is 1.4~4.1mg / L, and the total nitrogen removal rate is 95.2~98.6%.

9. A device for simultaneous denitrification and deodorization of livestock wastewater, comprising an inlet tank, a biofilm reactor, and an outlet tank connected in sequence, wherein the biofilm reactor is equipped with a hollow fiber membrane and an anaerobic ammonia oxidation module, and the hollow fiber membrane is connected to an oxygen cylinder.

10. The apparatus according to claim 9, characterized in that, The device also includes a magnetic stirrer and a water inlet pump; the water inlet pump is connected to the water inlet tank and the biofilm reactor, and the biofilm reactor is located on the magnetic stirrer.

Images