Method for preparing methane removal material and application thereof

Abstract

The invention belongs to the technical field of methane treatment, and particularly relates to a method for preparing a methane removal material and application of the method.The method comprises the steps that S1, methane-oxidizing bacteria in sludge are subjected to enrichment culture treatment, and inoculation liquid is obtained; s2, the inoculation liquid is subjected to fixation treatment, and a methane removal material is obtained; wherein the enrichment culture treatment comprises the following steps: (1) preparing a sludge suspension, and taking supernate to obtain an original inoculation solution; (2) carrying out passage treatment on the original inoculation liquid to obtain the inoculation liquid; the subculture treatment comprises the following steps: mixing an inorganic nutritive salt solution, methane and the original inoculation liquid, and carrying out subculture. The method for preparing the methane removal material has the advantages that the operation is simple, the condition is mild, the prepared material has a good methane removal effect, and the like, and the application prospect is wide. According to the methane removal material, methane in O2 in the environment is oxidized into CO2 and H2O under the condition of no human intervention by utilizing methane oxidizing bacteria in the methane removal material, so that the content of methane in the environment is reduced, and the material can realize in-situ efficient removal of methane in a drainage pipeline, can be stably used for a long time, and is environment-friendly and wide in application range.

Description

Technical Field

[0001] The present invention belongs to the technical field of methane treatment, and in particular relates to a method for preparing a methane removal material and application thereof. Background Art

[0002] The drainage pipe system is an important part of urban infrastructure. It is responsible for the collection and transportation of sewage and rainwater, and plays an important role in protecting the water environment and maintaining urban environmental hygiene and safety. At the same time, since the drainage pipes are often in anoxic or anaerobic state, the organic matter in the sewage can easily be converted into greenhouse gases or harmful gases such as methane and hydrogen sulfide under anaerobic conditions. Among them, methane is a greenhouse gas, and its warming potential is CO 2 The methane emission capacity of the current drainage system is about 0.2 to 3.1 g CH4. 4 / m 3 Sewage. With the increasing demand for ecological environment quality and the accelerated urbanization process, the scale of urban drainage pipes has gradually expanded. It can be foreseen that the contribution of methane emissions from drainage pipe systems to greenhouse gases will gradually increase and cannot be ignored. However, the methane emissions from drainage pipe systems are characterized by low concentration, instability, difficulty in utilization, and strong disorganization. In-situ removal of methane may be the preferred solution for methane removal from drainage pipes.

[0003] At present, the removal of harmful gases in drainage pipes is mainly done by regularly adding chemical agents to inhibit the activity of methanogenic microorganisms. This method has limited control effect on methane in drainage pipes and has a short duration of action. The chemical agents commonly used in this method mainly include alkaline substances such as NaOH and CaO, FeCl 3 Iron salts, NO 3 - -N, NO 2 - -N, free ammonia and other nitrogen-containing inorganic substances and other biological inhibitors. The use of these chemicals increases the cost of operation and maintenance of the drainage pipe system, introduces new pollutants into the drainage system, and the storage, transportation and addition of chemicals also pose certain safety risks.

[0004] Therefore, there is an urgent need to develop a more convenient, environmentally friendly, economical, efficient methane removal material, method and device suitable for in-situ methane removal in drainage pipes. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent. To this end, the present invention provides a method for preparing a methane removal material and its application. The method for preparing a methane removal material of the present invention has the advantages of simple operation, mild conditions, good methane removal effect of the prepared material, and broad application prospects. The methane removal material of the present invention utilizes methane oxidizing bacteria therein to utilize O in the environment without human intervention. 2 , oxidizing methane to CO 2 and H 2 O, thereby reducing the methane content in the environment. This material can achieve efficient in-situ methane removal in drainage pipes, can be used stably for a long time, is environmentally friendly, and has a wide range of applications.

[0006] In the first aspect of the present invention, a method for preparing a methane removal material is proposed. According to an embodiment of the present invention, it includes: S1: enriching and culturing the methane oxidizing bacteria in the sludge to obtain an inoculum; S2: fixing the inoculum to obtain a methane removal material; wherein the enrichment and culturing process includes the following steps: (1) preparing a sludge suspension, taking the supernatant, and obtaining an original inoculum; (2) subjecting the original inoculum to a subculture process to obtain the inoculum; the subculture process includes: mixing an inorganic nutrient salt solution, methane and the original inoculum for subculture. The method for preparing a methane removal material according to an embodiment of the present invention has the advantages of simple operation, mild conditions, and good methane removal effect of the prepared material, and has broad application prospects.

[0007] According to an embodiment of the present invention, the above method for preparing methane removal material may also have the following additional technical features: According to an embodiment of the present invention, the sludge comes from an anaerobic environment.

[0008] According to an embodiment of the present invention, the anaerobic environment includes a sewage pipe environment.

[0009] According to an embodiment of the present invention, the concentration of methanotrophic bacteria in the inoculation solution is 50-100 g DCW / L.

[0010] According to an embodiment of the present invention, the methane is the only carbon source for the growth of microorganisms in the original inoculum.

[0011] According to an embodiment of the present invention, the period of the subculture is 5 to 8 days, the number of subcultures is 5 to 8 times, and the pH value of the subculture is 6.5 to 7.5.

[0012] According to an embodiment of the present invention, the inorganic nutrient salt solution is used to provide nutrients other than carbon sources for the methanotrophic bacteria.

[0013] According to an embodiment of the present invention, the inorganic nutrient salt solution includes: phosphate, sulfate and nitrate.

[0014] According to an embodiment of the present invention, the methanotrophic bacteria is of the genus Methylocystis.

[0015] According to an embodiment of the present invention, the immobilization treatment comprises the following steps: A. mixing the inoculation solution with an immobilized material to obtain a methane removal material mixture; B. contacting the methane removal material mixture with methane to obtain a methane removal material.

[0016] According to an embodiment of the present invention, the immobilization material is an inert solid porous material.

[0017] According to an embodiment of the present invention, the immobilization material includes one or more of biochar, volcanic rock and ceramsite.

[0018] According to an embodiment of the present invention, based on 1 L of inoculation solution, the added amount of the immobilization material is 50 to 150 g.

[0019] According to an embodiment of the present invention, the contact treatment time is 12 to 48 hours, and the pH value of the contact treatment is 6.5 to 7.5.

[0020] In a second aspect of the present invention, the present invention provides a methane removal material. According to an embodiment of the present invention, the methane removal material is prepared by the method described in the first aspect. The methane removal material according to the embodiment of the present invention utilizes methane oxidizing bacteria in the material to remove O in the environment without human intervention. 2 , oxidizing methane to CO 2 and H 2 O, thereby reducing the methane content in the environment. This material can achieve efficient in-situ methane removal in drainage pipes, can be used for a long time and stably, is environmentally friendly, and has a wide range of applications.

[0021] In the third aspect of the present invention, the present invention provides a methane removal device. According to an embodiment of the present invention, the methane removal device comprises: the methane removal material according to the second aspect. The methane removal device according to the embodiment of the present invention has the advantages of simple operation, no direct contact with sewage, high methane removal efficiency, etc.

[0022] In the fourth aspect of the present invention, the present invention proposes the use of the method for preparing methane removal material described in the first aspect, the methane removal material described in the second aspect, and the methane removal device described in the third aspect in removing or reducing the methane content in a sample.

[0023] Those skilled in the art will appreciate that the features and advantages described above with respect to the method for preparing a methane removal material, a methane removal material, and a methane removal device are also applicable to this application and will not be described in detail herein.

[0024] According to an embodiment of the present invention, the above-mentioned preparation application may also have the following additional technical features:

[0025] According to an embodiment of the present invention, the sample originates from a sewage drainage pipe.

[0026] In a fifth aspect of the present invention, the present invention provides a method for removing or reducing the methane content in a sample. According to an embodiment of the present invention, the method comprises: contacting the sample with the methane removal material described in the second aspect; or passing the sample into the methane removal device described in the third aspect. According to the method of the embodiment of the present invention, by utilizing the methane oxidizing bacteria in the methane removal material, under the condition of no human intervention, the methane oxidizing bacteria in the environment are utilized to remove the methane. 2 , oxidizing methane to CO 2 and H 2 O, thereby reducing the methane content in the environment and achieving efficient removal or reduction of methane in the sample. This method can be used for a long time and stably, is environmentally friendly, and has a wide range of applications.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 Schematic diagram of the methane removal device in Example 2 of the present invention, wherein 1-1 is a methane removal material filler of the device, 1-2 is a porous outer ring (hole diameter is 2 mm, and the interval between holes is 5 mm), 1-3 is a porous inner ring (hole diameter is 2 mm, and the interval between holes is 5 mm), 1-4 is a porous supporting bottom (hole diameter is 2 mm, and the interval between holes is 5 mm), and 1-5 is a device hanging plate;

[0030] Figure 2Schematic diagram of a sewage pipe simulation reactor used in Example 2 of the present invention, wherein 2-1 is a vent valve at the top of the reactor, 2-2 is a water inlet valve, 2-3 is a water outlet valve, 2-4 is a gas sampling valve, 2-5 is a methane removal device, 2-6 is sewage pipe sediment (taken from a real sewage pipe), 2-7 is self-distributed water (simulating sewage in a sewage pipe), 2-8 is a water sampling valve, 2-9 is a water retaining weir, 2-10 is a simulated inspection shaft, 2-11 is a simulated sewage pipe cross pipe, 2-12 is a water inlet bucket, 2-13 is a water outlet bucket, 2-14 is a peristaltic pump, and 2-15 is a connecting silicone tube;

[0031] Figure 3 This is a diagram showing the change in methane concentration over time in the gas phase of a reactor simulating the removal of sewage from a methane removal pipeline in Example 2 of the present invention. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0033] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0034] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0035] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0036] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0037] Preparation method

[0038] The present invention proposes a method for preparing a methane removal material. According to an embodiment of the present invention, the method comprises: S1: enriching and culturing the methane oxidizing bacteria in the sludge to obtain an inoculum; S2: fixing the inoculum to obtain a methane removal material; wherein the enrichment and culturing comprises the following steps: (1) preparing a sludge suspension, taking the supernatant, and obtaining an original inoculum; (2) subculture the original inoculum to obtain the inoculum; the subculture comprises: mixing an inorganic nutrient salt solution and methane with the original inoculum for subculture. Thus, under the condition that methane is the only carbon source, enrichment and culturing are first performed to increase the concentration and activity of the methane oxidizing bacteria in the sludge, thereby providing basic conditions for the subsequent preparation of an efficient methane removal material; and then fixing the methane oxidizing bacteria to stably exist in the material, thereby facilitating long-term and efficient removal of methane in practical applications. The method for preparing a methane removal material according to an embodiment of the present invention has the advantages of simple operation, mild operating conditions, and good methane removal effect of the prepared material, and has a wide range of applications.

[0039] According to an embodiment of the present invention, the sludge is derived from an anaerobic environment. Thus, by screening the source of the sludge, sludge containing methanotrophic bacteria is preliminarily obtained, providing basic conditions for subsequent enrichment and cultivation of methanotrophic bacteria.

[0040] According to an embodiment of the present invention, the anaerobic environment includes a sewage pipe environment. Exemplarily, the sludge comes from the wall of a sewage pipe inspection well in a residential area, thereby, by screening the source of the sludge, sludge with methanotrophic bacteria is initially obtained, providing basic conditions for the subsequent enrichment and cultivation of methanotrophic bacteria.

[0041] According to an embodiment of the present invention, methane is the only carbon source for the growth of microorganisms in the original inoculum, thereby ensuring that the microorganisms are cultured under the condition of using methane as the only carbon source, and enriching and obtaining methanotrophic bacteria with strong methane metabolism ability.

[0042] According to an embodiment of the present invention, the concentration of methanotrophic bacteria in the inoculum is 50 to 100 gDCW / L. Exemplarily, the concentration of methanotrophic bacteria in the inoculum is 50 gDCW / L, 60 gDCW / L, 70 gDCW / L, 80 gDCW / L, 90 gDCW / L, 100 gDCW / L, preferably 50 to 80 gDCW / L, more preferably 70 gDCW / L; thus, the final concentration of methanotrophic bacteria in the inoculum is used to determine whether the enrichment culture is successfully achieved, providing a reference for the subsequent mixing ratio with the immobilized material.

[0043] According to an embodiment of the present invention, the cycle of the subculture is 5 to 8 days, the number of subcultures is 5 to 8 times, and the pH value of the subculture is 6.5 to 7.5. Exemplarily, the cycle of the subculture is 5 days, 6 days, 7 days, 8 days, preferably 5 to 7 days, and more preferably 7 days; the number of subcultures is 5 times, 6 times, 7 times, 8 times, preferably 5 to 6 times, and more preferably 6 times; the pH value of the subculture is 6.5, 6.7, 6.9, 7.0, 7.3, 7.5, preferably 6.9 to 7.3, and more preferably 7.0; thus, by controlling the culture cycle, number of times and pH value, the culture conditions are optimized, and the growth efficiency of methanotrophic bacteria and the stability of metabolic methane are improved.

[0044] According to an embodiment of the present invention, the inorganic nutrient salt solution is used to provide nutrients other than the carbon source for the methanotrophic bacteria. Thus, the inorganic nutrient salt solution provides nutrients other than the carbon source for the methanotrophic bacteria, assists in conditional enrichment culture, and enriches and obtains methanotrophic bacteria with strong methane metabolism ability and high activity.

[0045] According to an embodiment of the present invention, the inorganic nutrient salt solution includes: phosphate, sulfate and nitrate. Exemplarily, the inorganic nutrient salt solution includes Na 2 HPO 4 , KH 2 PO 4 MgSO 4 , CaCl 2 , K 2 SO 4 and KNO 3 And other ingredients, thereby providing nutrient salt components for methane oxidizing bacteria, promoting their efficient reproduction and accelerating the conditional enrichment culture process.

[0046] According to an embodiment of the present invention, the methanotrophic bacteria are of the genus Methylocystis. Therefore, under the action of the methanotrophic bacteria, methane can be metabolized efficiently.

[0047] According to an embodiment of the present invention, the immobilization treatment comprises the following steps: A. mixing the inoculation solution with the immobilized material to obtain a methane removal material mixture; B. contacting the methane removal material mixture with methane to obtain a methane removal material. Thus, through the immobilization treatment, the methane oxidizing bacteria are stably present on the surface of the immobilized material, which enhances the practicality and effectiveness of the methane removal material and facilitates the methane oxidizing bacteria to efficiently metabolize methane.

[0048] According to an embodiment of the present invention, the immobilization material is an inert solid porous material. The inert solid material immobilizes the methane oxidizing bacteria, which is convenient for practical application. In addition, the inert solid porous material is conducive to the adsorption of methane gas and promotes the contact between the methane oxidizing bacteria and the methane gas in the environment. The porous nature of the inert porous material provides a suitable microenvironment for the methane oxidizing bacteria, which is conducive to the fixation and activity maintenance of the methane oxidizing bacteria, and is conducive to the efficient metabolism of methane.

[0049] According to an embodiment of the present invention, the immobilized material includes one or more of biochar, volcanic rock and ceramsite. Therefore, the different immobilized materials have different physical properties and can be selected according to actual application requirements to achieve a better methane removal effect.

[0050] According to an embodiment of the present invention, based on 1L of inoculation solution, the amount of the immobilized material added is 50 to 150g. Exemplarily, based on 1L of inoculation solution, the amount of the immobilized material added is 50g, 60g, 70g, 80g, 90g, 100g, 110g, 120g, 130g, 140g, 150g, preferably 80 to 120g, more preferably 100g; thus, by adjusting the amount of immobilized material added, the density and adsorption capacity of the methane removal material can be controlled to achieve the best methane removal effect. It should be noted that based on 1L of inoculation solution, the amount of immobilized material added is 50 to 150g. In actual applications, the amount of specific inoculation solution added and the amount of immobilized material added can be adjusted or expanded according to the actual application situation.

[0051] According to an embodiment of the present invention, the contact treatment time is 12 to 48 hours, and the pH value of the contact treatment is 6.5 to 7.5. Exemplarily, the contact treatment time is 12 hours, 16 hours, 24 hours, 28 hours, 32 hours, 36 hours, 40 hours, 44 hours, 48 ​​hours, preferably 12 to 36 hours, more preferably 24 hours; the pH value of the contact treatment is 6.5, 6.7, 6.9, 7.0, 7.3, 7.5, preferably 6.9 to 7.3, more preferably 7.0; thereby, it is ensured that the methanotrophic bacteria are fully in contact with methane, the activity of the methanotrophic bacteria is guaranteed, and the methane removal efficiency of the methane removal material is further improved.

[0052] Methane Removal Materials

[0053] The present invention provides a methane removal material. According to an embodiment of the present invention, the methane removal material is prepared by the above method. The methane removal material according to the embodiment of the present invention utilizes methane oxidizing bacteria in the material to remove methane from the environment without human intervention. 2 , oxidizing methane to CO 2 and H 2O, thereby reducing the methane content in the environment. The material can be used to achieve efficient in-situ methane removal in drainage pipes. The material can be used for a long time and stably, is environmentally friendly, and has a wide range of applications.

[0054] Methane removal unit

[0055] The present invention provides a methane removal device. According to an embodiment of the present invention, the methane removal device comprises: the aforementioned methane removal material. The methane removal device according to the embodiment of the present invention has the advantages of simple device operation and high methane removal efficiency.

[0056] application

[0057] The present invention proposes the use of the aforementioned method for preparing a methane removal material, the aforementioned methane removal material, and the aforementioned methane removal device in removing or reducing the methane content in a sample.

[0058] Those skilled in the art will appreciate that the features and advantages described above with respect to the method for preparing a methane removal material, a methane removal material, and a methane removal device are also applicable to this application and will not be described in detail herein.

[0059] According to an embodiment of the present invention, the sample is derived from a sewage drainage pipe. Exemplarily, the aforementioned method for preparing a methane removal material, the aforementioned methane removal material, the aforementioned methane removal device, or the application of reducing the methane content in a sample can be applied to the removal of methane in a sewage drainage pipe, thereby achieving long-term, efficient, and environmentally friendly in-situ removal of methane.

[0060] Methods for removing or reducing the methane content in samples

[0061] The present invention proposes a method for removing or reducing the methane content in a sample. According to an embodiment of the present invention, the method comprises: contacting the sample with the aforementioned methane removal material; or passing the sample into the aforementioned methane removal device. According to the method of the embodiment of the present invention, by utilizing the methane oxidizing bacteria in the methane removal material, under the condition of no human intervention, the methane oxidizing bacteria in the environment are utilized to reduce the methane content in the sample. 2 , oxidizing methane to CO 2 and H 2 O, thereby reducing the methane content in the environment and achieving efficient removal or reduction of methane in the sample. This method can be used for a long time and stably, is environmentally friendly, and has a wide range of applications.

[0062] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0063] Example 1: Preparation of methane removal material for sewer pipe system

[0064] 1. Enrichment culture to obtain methane oxidizing bacteria liquid

[0065] (1) Source of sludge samples: A sterile shovel was used to collect several sludge samples from the wall of a drainage pipe inspection well in a residential area. The thickness of the sludge samples was about 2 to 3 cm, and the sampling location was the middle of the inspection well wall. The sludge samples were stored in sterile sampling bottles and transported to the laboratory at 4°C for subsequent processing.

[0066] (2) Pretreatment of sludge samples

[0067] After removing impurity particles (such as hair, large gravel, etc.) from the sludge sample, weigh 30.0 g of the sludge sample and put it into 360 mL of 0.1 mol / L phosphate buffer. Use a glass rod to stir evenly to fully suspend the sludge sample. After standing, take the supernatant to obtain the original inoculum solution.

[0068] (3) Preparation of inorganic nutrient salt solution

[0069] The formula of the inorganic nutrient salt solution is shown in Table 1.

[0070] Table 1 Formula of inorganic nutrient salt solution

[0071]

[0072] (4) Enrichment culture

[0073] Add 20 mL of component A, 1 mL of component B and 2.5 mL of component C described in the above-mentioned inorganic nutrient salt solution formula in sequence, then add 10 mL of the original inoculum solution prepared in step (2), add sterile water to make the volume to 50 mL, mix well, and adjust the pH to 7.0 with 1 mol / L HCl solution and 1 mol / L NaOH solution to obtain inoculum solution I.

[0074] The inoculum solution I was added to a sterile 100 mL serum bottle and sealed with an isobutyl rubber stopper and an aluminum alloy cap. After the serum bottle was sealed, CH was injected into the sealed serum bottle using a sterile airtight needle by air displacement. 4 (gas purity ≥ 99.9%) as the only carbon source for the growth of microorganisms in the inoculated bacterial solution I, the CH4 The concentration is 5% (v / v). The serum bottle is placed in a constant temperature shaking box for culture in the dark, the constant temperature shaking box is set at 30°C and 150rpm, and 7 days is a culture cycle.

[0075] (4) Subculture

[0076] The subculture was performed every 7 days at a subculture ratio of 10% (v / v). The specific subculture method is as follows:

[0077] According to the method of step (4), take the same volume of inorganic culture salt solution A, solution B and solution C and mix them with the 5mL bacterial solution after 7 days of culture, add sterile water to make the volume 50mL, and adjust the pH to 7.0 with 1mol / L HCl solution and 1mol / L NaOH solution to obtain inoculated bacterial solution II. Then add inoculated bacterial solution II to a new 100ml serum bottle and inject CH4 into it in the same way as step (4). 4 As the carbon source, the same constant temperature shaking culture conditions were set, and the subculture operation was repeated for a total of 6 cycles to obtain the inoculum bacterial solution N, which was then subjected to microbial species detection.

[0078] The results showed that the methane removal bacterial solution was rich in methane oxidizing bacteria, mainly Methylocystis, and the N concentration of the inoculated bacterial solution was 70 g DCW / L.

[0079] 2. Preparation of methane removal materials for drainage pipe systems

[0080] (1) Sources of biochar

[0081] The biochar used by the inventor is bamboo charcoal biochar, and the BET specific surface area method is used to determine the specific surface area, average pore size and pore volume of the biochar.

[0082] The results showed that the particle size of bamboo charcoal biochar was 3-5 mm and the specific surface area was 33.83 m 2 / g, average pore diameter is 1.69nm, pore volume is 0.01cm 3 / g. The porous and large specific surface area characteristics of biochar can provide favorable conditions for the attachment of microorganisms.

[0083] (2) Preparation of methane removal materials for drainage pipe systems

[0084] 5 g of biochar was fully mixed with 50 mL of inoculated bacterial solution N to fix the methane oxidizing bacteria on the surface of the biochar to obtain a methane removal material mixture. The methane removal material mixture was cultured in a sealed 100 mL serum bottle at 30 °C and 100 rpm for 24 h. CH4 was injected into the sealed serum bottle by air displacement using a sterile airtight needle. 4(gas purity ≥ 99.9%) as the only carbon source for microbial growth in the methane removal material mixture, the headspace CH 4 The concentration is 5% (v / v), and after removing the bacterial solution, the methane removal material for the drainage pipe system is obtained.

[0085] Example 2: Simulated application of methane removal materials in sewage pipe systems

[0086] (1) Design of sewage pipe simulation reactor

[0087] The schematic diagram of the methane removal device in the embodiment of the present invention is shown in Figure 1 .

[0088] The sewage pipe simulation reactor used in this embodiment is as follows Figure 2 As shown in the figure, it consists of a simulated vertical shaft with dimensions of 100mm×100mm×300mm in length×width×height and a simulated sewage horizontal pipe with dimensions of 400mm×80mm in length×width. The cross section of the horizontal pipe consists of a semicircle with a diameter of 80mm and a rectangle with dimensions of 80mm×40mm in length×height. A water flow retention area with a length of 30mm is set on the left and right of the horizontal pipe, and a water retaining weir with a height of 60mm is set (as shown in the figure). Figure 2 2-9 in the figure). Outside the water flow retention area, about 0.23L of drainage pipe sludge (collected from real pipe sludge in a sewage pipe section) was filled.

[0089] (2) Simulate domestic sewage in sewage pipes

[0090] The experimental water used in this example is artificially simulated domestic sewage, in which the pollutant concentrations are: chemical oxygen demand COD 300mg / L, ammonia nitrogen NH 3 -N 20mg N / L, sulfate SO 4 2- 60mg S / L, pH 7.0, which is similar to the concentration of common domestic sewage pollutants. 2 Aeration was used to increase the dissolved oxygen concentration (DO concentration) in the artificially simulated biological sewage to 0.5 mgO 2 / L to simulate the anaerobic environment of sewage pipes.

[0091] (3) Simulation application of methane removal materials in sewage pipe systems

[0092] In this embodiment, the methane removal device is placed Figure 1 The device shown is installed in Figure 2 Shown is a simulated reactor shaft.

[0093] In this embodiment, the simulated reactor operation consists of a startup period from day 1 to day 36 (I), a methane concentration stabilization period from day 37 to day 46 (II), and a methane removal device deployment period from day 47 to day 76 (III).

[0094] Place artificial simulated domestic sewage in the water inlet bucket (such as Figure 2 2-12), the artificial simulated domestic sewage is pumped through the silicone water pipe through the water inlet valve (as shown in FIG. Figure 2 The artificially simulated domestic sewage flows through the simulated horizontal pipe and then passes through the outlet valve (by Figure 2 2-3 in the figure) out of the reactor and into the water outlet bucket (by Figure 2 2-4 in FIG). The artificial simulated domestic sewage in the water inlet bucket is replaced every day to ensure the freshness of the artificial simulated domestic sewage.

[0095] (4) Determination of methane concentration

[0096] Take gas samples from two valves (such as Figure 2 2-4 in the figure) take 10mL gas sample and store it in a 10mL aluminum air bag. Use gas chromatography to detect the methane concentration of the gas sample obtained from the two gas sampling valves. Sampling is done once every 24 hours, and two gas bags of gas samples are sampled from the gas sampling valves each time. Sampling and testing are carried out for 76 days.

[0097] (5) Calculation of methane concentration change and removal rate

[0098] The change of methane concentration over time in the gas phase of the simulated reactor of the methane removal device to remove the sewage pipeline is shown in Figure 3 .

[0099] After nearly a month of reactor acclimation and startup, the methane concentration in the reactor gas phase increased and finally stabilized at 3765.96-4557.16 ppm, with an average of 4070.36 ppm. During the period of methane removal device deployment (47th to 76th day), the methane concentration in the reactor gas phase decreased to 90.90-874.16 ppm, with an average of 425.34 ppm. Compared with the methane concentration stabilization period without deployment (37th to 46th day), the average methane removal rate (E) was 89.55%. The average methane removal rate was calculated according to the following formula:

[0100]

[0101] Where, E is the average methane removal rate, %;

[0102] C before is the average concentration of methane during the stable period before the deployment of the methane removal device;

[0103] Cafter is the average methane concentration after the methane removal device is deployed.

[0104] The above results indicate that the above method and the methane removal device can be used for a long period of time (up to 30 days) without human intervention (such as replacing materials and supplementing inorganic nutrients). In addition, the methane removal device does not contact the sewage in the horizontal pipe and does not interfere with the transportation of sewage, so it can achieve efficient removal of methane in the simulated reactor. In practical applications, the method and device can achieve efficient, long-term, economical and environmentally friendly methane emission reduction in sewage pipes, and can effectively reduce the methane content in sewage pipes.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0106] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a methane removal material, characterized in that: include: S1: enriching and culturing the methane oxidizing bacteria in the sludge to obtain an inoculum solution; S2: Fixing the inoculum solution to obtain a methane removal material; Wherein, the enrichment culture process comprises the following steps: (1) preparing a sludge suspension, taking the supernatant, and obtaining an original inoculum solution; (2) performing a subculture process on the original inoculum to obtain the inoculum; The subculture treatment comprises: mixing an inorganic nutrient salt solution and methane with the original inoculation solution to perform subculture.

2. The method according to claim 1, characterized in that The sludge is derived from an anaerobic environment; Optionally, the anaerobic environment comprises a sewer environment; Optionally, the concentration of methanotrophic bacteria in the inoculum is 50-100 gDCW / L; Optionally, the methane is the sole carbon source for the growth of microorganisms in the original inoculum; Optionally, the subculture cycle is 5 to 8 days, the number of subcultures is 5 to 8 times, and the pH value of the subculture is 6.5 to 7.5; Optionally, the inorganic nutrient salt solution is used to provide nutrients other than a carbon source to the methanotrophic bacteria; Optionally, the inorganic nutrient salt solution includes phosphates, sulfates and nitrates.

3. The method according to claim 1, characterized in that: The methanotrophic bacteria are of the genus Methylocystis.

4. The method according to claim 1, characterized in that: The fixing process comprises the following steps: A. mixing the inoculum solution with an immobilized material to obtain a methane removal material mixture; B. contacting the methane removal material mixture with methane to obtain a methane removal material.

5. The method according to claim 4, characterized in that The immobilization material is an inert solid porous material; Optionally, the immobilization material includes one or more of biochar, volcanic rock and ceramsite; Optionally, based on 1 L of inoculum solution, the amount of the immobilization material added is 50 to 150 g.

6. The method according to claim 4, characterized in that The contact treatment time is 12 to 48 hours, and the pH value of the contact treatment is 6.5 to 7.

5.

7. A methane removal material, characterized in that: The methane removal material is prepared by the method according to any one of claims 1 to 6.

8. A methane removal device, characterized in that: The methane removal device comprises: the methane removal material according to claim 7.

9. Use of the method for preparing a methane removal material according to any one of claims 1 to 6, the methane removal material according to claim 7, and the methane removal device according to claim 8 in removing or reducing the methane content in a sample; Optionally, the sample originates from a sewage drain.

10. A method for removing or reducing the methane content in a sample, characterized in that: The method comprises: contacting the sample with the methane removal material of claim 7, or, The sample is passed into the methane removal device of claim 8.

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