Piezoelectric biological hybrid, and preparation method and application thereof

Abstract

This invention discloses a piezoelectric biohybrid, belonging to the field of wastewater treatment and resource utilization technology. The piezoelectric biohybrid is composed of barium titanate particles and anaerobic sludge, with the barium titanate particles exhibiting piezoelectricity. This invention innovatively utilizes the abundant mechanical stress generated by fluid flow, mechanical stirring, and microbial gas production in the anaerobic fermentation system. The piezoelectric biohybrid provided by this invention converts the mechanical energy of this stress into a built-in electric field within the anaerobic fermentation system, providing a new method for driving interspecies electron transfer. This effectively enhances interspecies electron transfer between acid-producing bacteria and methanogenic bacteria, increasing methane yield under anaerobic fermentation. Furthermore, the piezoelectric biohybrid provided by this invention has the advantages of simple structure, reasonable design, and ease of manufacture.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment and resource utilization technology, and more specifically, relates to a piezoelectric bio-hybrid, its preparation method and application. Background Technology

[0002] Wastewater treatment is shifting from traditional pollution control to a new stage of wastewater resource recovery and energy conversion. Anaerobic fermentation, as a mainstream wastewater energy conversion technology, can convert residual sludge and other organic waste into methane, simultaneously achieving the reduction and energy conversion of organic waste. In a typical anaerobic fermentation system, acid-producing bacteria first convert large organic molecules into small volatile fatty acids (VFAs), H2, and CO2; subsequently, methanogens use H2 and formic acid as electron donors to reduce CO2 or acetic acid to CH4. However, the interspecies electron transfer efficiency between acid-producing and methanogens has long been considered a key technical bottleneck restricting the methane yield of anaerobic fermentation systems. On the one hand, electron transfer mediated by H2 / formic acid is limited by the diffusion mass transfer kinetics between the gas and liquid phases, resulting in the inability of electron donors to be utilized by methanogens in a timely manner, thus inhibiting the metabolic activity of methanogens; on the other hand, the microporous structure inside activated sludge significantly reduces the diffusion flux of H2 / formic acid, causing local accumulation of H2 / formic acid, thereby hindering the metabolic activity of acid-producing bacteria. Therefore, enhancing interspecies electron transfer is key to releasing the activity of acid-producing and methanogenic bacteria and maximizing methane production.

[0003] Current research primarily focuses on enhancing interspecies electron transfer during anaerobic fermentation by introducing carbon-based conductive materials (such as activated carbon, biochar, and carbon nanotubes) and iron-based electron mediators (Fe3O4, zero-valent iron, and hematite). The former can establish a bridge for interspecies electron transfer between acid-producing and methanogenic bacteria, while the latter can utilize Fe... 2+ / Fe 3+ Redox methods can enhance interspecies electron transport. However, neither strategy can overcome the physical limitations of electron mediator diffusion kinetics and the ohmic impedance of the materials themselves, resulting in limited effectiveness in enhancing interspecies electron transport.

[0004] Therefore, developing a novel technical solution to effectively enhance interspecies electron transfer and improve methane yield under anaerobic fermentation is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] 1. The problem to be solved

[0006] To address the limitations of existing technologies where carbon-based conductive materials and iron-based electronic mediators cannot overcome the physical constraints of diffusion kinetics and the ohmic impedance of the materials themselves, and thus have limited effectiveness in enhancing the activity of acid-producing and methanogenic bacteria and increasing methane yield by strengthening interspecies electron transfer pathways, this invention provides a piezoelectric bio-hybrid. As a technical solution different from carbon-based conductive materials and iron-based electronic mediators, it can effectively enhance interspecies electron transfer between acid-producing and methanogenic bacteria during anaerobic fermentation, thereby increasing the methane yield of anaerobic fermentation.

[0007] 2. Technical Solution

[0008] This invention innovatively utilizes the abundant mechanical stress generated by fluid flow, mechanical stirring, and microbial gas production in anaerobic fermentation systems. Through the piezoelectric biohybrid provided by this invention, the mechanical energy of this stress is converted into a built-in electric field within the anaerobic fermentation system, providing a new mechanism for driving interspecies electron transfer. Specifically, barium titanate (BaTiO3) in the piezoelectric biohybrid is a typical piezoelectric material. Under applied mechanical stress, its particles undergo reversible displacement of their positive and negative charge centers, generating a localized interfacial micro-electric field, thereby driving the directional transfer of electrons between acid-producing and methanogenic bacteria.

[0009] Based on this, the technical solution adopted in this invention is as follows:

[0010] [1. Piezoelectric bio-hybrid]

[0011] The first aspect of the present invention provides a piezoelectric bio-hybrid composed of barium titanate particles and anaerobic sludge, wherein the barium titanate particles are piezoelectric.

[0012] As a preferred embodiment of any of the first aspects of the present invention, the mass ratio of barium titanate particles to suspended solids in anaerobic sludge is 1:(2~20), and more preferably 1:(4~12).

[0013] As a preferred embodiment of any of the first aspects of the present invention, the anaerobic sludge is sludge used for anaerobic fermentation to produce methane.

[0014] Furthermore, the anaerobic sludge contains acid-producing bacteria and methanogenic bacteria.

[0015] [2. Preparation method of piezoelectric biological hybrids]

[0016] The second aspect of this invention provides a method for preparing the piezoelectric bio-hybrid provided in the first aspect of this invention, the method comprising the following steps:

[0017] S1: Add barium titanate particles with piezoelectricity to water and ultrasonically treat them to obtain a barium titanate particle dispersion.

[0018] S2: Add anaerobic sludge to phosphate buffer solution, shake and disperse to obtain anaerobic sludge dispersion;

[0019] S3: In an inert atmosphere, the anaerobic sludge dispersion is added to the barium titanate particle dispersion while stirring. After stirring evenly, a dispersion containing piezoelectric bio-hybrids is obtained.

[0020] S4: After the dispersion containing the piezoelectric bio-hybrid is allowed to stand and separate into layers, the supernatant is removed to obtain the piezoelectric bio-hybrid.

[0021] As a preferred embodiment of any of the second aspects of the present invention, the concentration of the barium titanate particle dispersion is 0.1 g / L to 1 g / L; and / or

[0022] The mixed liquor suspended solids (MLSS) concentration of the anaerobic sludge dispersion is 1 g / L to 10 g / L; and / or

[0023] The volume ratio of barium titanate particle dispersion to anaerobic sludge dispersion is (0.1~10):1.

[0024] Furthermore, the concentration of the barium titanate particle dispersion is 0.3 g / L to 0.7 g / L; and / or

[0025] The MLSS of anaerobic sludge dispersion is 3 g / L to 7 g / L; and / or

[0026] The volume ratio of barium titanate particle dispersion to anaerobic sludge dispersion is (0.5~5):1.

[0027] As a preferred embodiment of any of the second aspects of the present invention, the ultrasonic treatment time in S1 is 0.5 h to 2 h; and / or

[0028] The concentration of phosphate buffer in S2 is 50 mM to 150 mM; and / or

[0029] The addition rate of the anaerobic sludge dispersion in S3 is 10 mL / min to 60 mL / min, and the stirring speed is 30 rpm to 70 rpm.

[0030] Furthermore, the duration of ultrasonic treatment in S1 is 0.8 h to 1.2 h; and / or

[0031] The concentration of phosphate buffer in S2 is 80 mM to 120 mM; and / or

[0032] The addition rate of the anaerobic sludge dispersion in S3 is 10 mL / min to 30 mL / min, and the stirring speed is 40 rpm to 60 rpm.

[0033] [3. Applications of piezoelectric biological hybrids]

[0034] The third aspect of this invention provides the application of the piezoelectric bio-hybrid provided in the first aspect of this invention or the piezoelectric bio-hybrid prepared by the preparation method provided in the second aspect of this invention in the anaerobic fermentation of organic matter to produce methane.

[0035] As a preferred embodiment of any of the third aspects of the present invention, the application includes the following steps:

[0036] A. Add piezoelectric bio-hybrids to the anaerobic reactor and continuously pump in organic wastewater;

[0037] B. Control the hydraulic retention time of the anaerobic reactor to be 12 h to 72 h, the stirring speed to be 20 rpm to 180 rpm, and the fermentation temperature to be 25℃ to 45℃.

[0038] When the piezoelectric biohybrid provided by this invention is used in anaerobic fermentation, the stirring speed should not be too slow or too fast. If the stirring speed is too slow, for example, less than 20 rpm, the organic matter in the wastewater will not come into complete contact with the piezoelectric biohybrid, leading to a decrease in methane yield. Conversely, if the stirring speed is too fast, for example, greater than 180 rpm, the mechanical stress generated by stirring is too great, resulting in an excessively strong piezoelectric effect that exceeds the tolerance range of some bacteria in the anaerobic sludge, causing some bacteria to be inactivated and thus reducing the methane yield.

[0039] Furthermore, in section B, the hydraulic retention time of the anaerobic reactor is controlled to be 12 h to 36 h, the stirring speed to be 50 rpm to 150 rpm, and the fermentation temperature to be 30℃ to 40℃.

[0040] As a preferred embodiment of any of the third aspects of the present invention, the concentration of the piezoelectric bio-hybrid is 0.1 g / L to 10 g / L, and the concentration of COD in the organic wastewater is 2 to 8 g / L.

[0041] Furthermore, the concentration of the piezoelectric bio-hybrid is 0.2 g / L to 5 g / L, and more preferably 0.2 g / L to 2 g / L.

[0042] As a preferred embodiment of any third aspect of the present invention, the methane yield is greater than or equal to 200 mL / g COD, the maximum methane generation potential is greater than or equal to 200 mL / g COD, and the maximum methane production rate is greater than or equal to 30 mL / (g COD·h).

[0043] Furthermore, the methane production is greater than or equal to 250 mL / g COD, the maximum methane production potential is greater than or equal to 250 mL / g COD, and the maximum methane production rate is greater than or equal to 35 mL / (g COD·h).

[0044] 3. Beneficial effects

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0046] (1) This invention provides a piezoelectric biohybrid for the first time. It utilizes the mechanical stress generated by fluid flow, mechanical stirring, and microbial gas production in the anaerobic fermentation system to stimulate the piezoelectric effect of barium titanate nanoparticles in the piezoelectric biohybrid, thereby generating a local interfacial micro-electric field. This drives the directional transfer of electrons between acid-producing bacteria and methanogens in the surrounding area, effectively enhancing the interspecies electron transfer between acid-producing bacteria and methanogens. This breaks through the technical bottleneck of the traditional anaerobic fermentation methane yield being limited by the slow interspecies electron transfer between acid-producing bacteria and methanogens. Moreover, the barium titanate particles in the piezoelectric biohybrid are uniformly distributed and have good contact with the anaerobic sludge. Compared with the existing technologies using carbon-based conductive materials and iron-based electronic mediators, there are no physical limitations of diffusion kinetics and the ohmic impedance of the material itself. The enhancement effect of interspecies electron transfer is more significant, ultimately effectively improving the methane yield under anaerobic fermentation.

[0047] (2) The method for preparing piezoelectric biological hybrids provided by the present invention has a simple process, reasonable design, and is easy to promote and apply in industry.

[0048] (3) When the piezoelectric bio-hybrid provided by this invention is applied to anaerobic fermentation for methane production, the methane yield is increased by 123.45% compared to traditional anaerobic fermentation for methane production, and the maximum methane production potential (P) is also increased. m ) and maximum methane production rate (R m All of these have significantly improved, further advancing the process of energy and resource utilization of organic waste in wastewater. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the anaerobic reactor in Test Example 2 of the present invention;

[0050] Figure 2 This is a trend graph showing the methane yield under anaerobic fermentation of the present invention with and without piezoelectric bio-hybrids (Test Example 2).

[0051] Figure 3 This is a trend graph showing the methane yield of piezoelectric bio-hybrids (test examples 2, 4, and 5) obtained by different volume ratios of barium titanate nanoparticle dispersion and anaerobic sludge dispersion under anaerobic fermentation in this invention.

[0052] Figure 4 This is a trend graph showing the methane yield of piezoelectric bio-hybrids (test examples 2, 6, and 7) under anaerobic fermentation at different stirring speeds in this invention.

[0053] Figure 5This is a trend graph showing the methane yield of piezoelectric bio-hybrids (test examples 2, 4, and 8) under anaerobic fermentation with different dosages in this invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1. Inlet; 2. Outlet; 3. Gas outlet; 4. Methane; 5. Organic matter; 6. Piezoelectric bio-hybrid. Detailed Implementation

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0057] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0058] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0059] Concentration, amount, and other numerical data may be presented in range format herein. It should be understood that such range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly stated as the limits of the range, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly stated. For example, a range of values ​​from about 1 to about 4.5 should be interpreted to include not only the explicitly stated limits of 1 to 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that describe only a single value, such as "less than about 4.5," which should be interpreted to include all the values ​​and ranges described above. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described.

[0060] It should be noted that, in the specific implementation method, the COD in the organic wastewater is measured by rapid digestion spectrophotometry; the methane yield is obtained by calculating the difference in COD content between the influent and effluent and the corresponding volume of the generated mixed gas and methane concentration; the maximum methane generation potential (P) is... m ) and maximum methane production rate (R m ) is obtained through the methane cumulative gas production curve model Gompertz (e.g. Figures 2-5 The model obtained by fitting (as shown) is specifically P(t) = P m *exp(-exp(Rm *exp(1)*(λ-t) / P m +1)).

[0061] like Figure 1 As shown, taking the anaerobic fermentation process in Test Example 2 as an example, the process of anaerobic fermentation to produce methane using the piezoelectric bio-hybrid of the present invention is as follows: Organic wastewater is continuously pumped into the anaerobic reactor from the inlet 1 and flows out from the outlet 2. The organic matter 5 in the anaerobic reactor undergoes anaerobic fermentation under the action of the piezoelectric bio-hybrid 6 to produce methane 4, which is collected from the outlet 3.

[0062] The present invention will be further described below with reference to specific embodiments.

[0063] Materials used in preparation:

[0064] piezoelectric barium titanate nanoparticles (BaTiO3, BTO), non-piezoelectric barium titanate nanoparticles (No... The BTO (Biochemical Oxygen Demand) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the anaerobic sludge refers to the sludge used for anaerobic fermentation, which was purchased from Nanjing Fuyue Environmental Protection Technology Co., Ltd.; the organic wastewater was prepared in-house, with a COD concentration of 5 g / L.

[0065] Example 1

[0066] This embodiment provides a piezoelectric bio-hybrid dispersion, which is composed of piezoelectric barium titanate nanoparticles (BTO) and anaerobic sludge. The specific steps are as follows:

[0067] (1) Preparation of piezoelectric barium titanate nanoparticle dispersion:

[0068] Weigh 0.5 g of barium piezoelectric titanate nanoparticles (BTO), add them to 1.0 L of deionized water, and sonicate for 1.0 h to obtain a 1.0 L volume of barium piezoelectric titanate nanoparticle dispersion with a concentration of 0.5 g / L.

[0069] (2) Preparation of anaerobic sludge dispersion

[0070] Take 250 mL of anaerobic sludge with a mixed liquor suspended solids concentration (MLSS) of 20 g / L, add it to 750 mL of 100 mM phosphate buffer solution, and shake it thoroughly with glass beads to obtain an anaerobic sludge dispersion with a volume of 1.0 L and an MLSS of 5.0 g / L.

[0071] (3) Hybridization forms a piezoelectric bio-hybrid dispersion

[0072] Under nitrogen protection, the piezoelectric barium titanate nanoparticle dispersion from step (1) was stirred at 50 rpm. Then, the anaerobic sludge dispersion from step (2) was added dropwise at a rate of 20 mL / min and stirred until homogeneous to obtain a piezoelectric bio-hybrid dispersion, wherein the volume ratio of the piezoelectric barium titanate nanoparticle dispersion to the anaerobic sludge dispersion was 1:1.

[0073] Example 2

[0074] This embodiment provides a piezoelectric bio-hybrid dispersion, which is composed of piezoelectric barium titanate nanoparticles (BTO) and anaerobic sludge. The specific steps are basically the same as those in Example 1, except that in step (3), the volume ratio of barium titanate nanoparticle dispersion to anaerobic sludge dispersion is 2:1.

[0075] Comparative Example 1

[0076] This comparative example provides a piezoelectric-free biohybrid dispersion composed of piezoelectric-free barium titanate nanoparticles (No. The process involves a mixture of barium titanate (BTO) and anaerobic sludge, and the specific steps are basically the same as in Example 1, except that non-piezoelectric barium titanate nanoparticles (No. 1) are used. BTO was used to replace barium piezoelectric titanate nanoparticles (BTO).

[0077] Test Example 1

[0078] This test case is used to evaluate methane yield under a traditional anaerobic fermentation method. The specific steps are as follows:

[0079] Organic wastewater was continuously pumped into a 2.0 L anaerobic reactor, with the hydraulic retention time (HRT) controlled at 24 h. Simultaneously, the stirring speed in the reactor was controlled at 100 rpm, and the fermentation temperature at 35℃ for anaerobic fermentation to produce methane. (Refer to...) Figure 1 As shown.

[0080] The methane yield at different time points was calculated by testing the methane concentration and gas production volume in the anaerobic reactor. The final methane yield under the conventional anaerobic fermentation method was 127.078 mL / g COD.

[0081] Test Example 2

[0082] This test example was used to test the methane yield of the piezoelectric bio-hybrid prepared in Example 1 under anaerobic fermentation. The specific steps were basically the same as in Test Example 1, except that 0.364 L of the piezoelectric bio-hybrid dispersion prepared in Example 1 was added before pumping in the high-concentration organic wastewater, equivalent to a dosage of 1 g of piezoelectric bio-hybrid. Figure 1 As shown.

[0083] Test Example 3

[0084] This test example was used to test the methane yield of the non-piezoelectric bio-hybrid prepared in Comparative Example 1 under anaerobic fermentation. The specific steps were basically the same as those in Test Example 1, except that 0.364 L of the non-piezoelectric bio-hybrid dispersion prepared in Comparative Example 1 was added before pumping in the high-concentration organic wastewater.

[0085] The test results for Test Example 2 and Test 3 are shown in Table 1 and Figure 2 As shown.

[0086] Table 1. Performance comparison of piezoelectric hybrid organisms (Test Example 2) and non-piezoelectric hybrid organisms (Test Example 3) in anaerobic fermentation.

[0087]

[0088] Combining the results of test example 1 and Table 1 and Figure 2 It was found that the methane yield with the participation of the piezoelectric bio-hybrid (Example 1) was 283.962 mL / g COD, significantly higher than the methane yield under the conventional anaerobic fermentation method (127.078 mL / g COD), representing a 123.45% increase in methane yield. This indicates that the piezoelectric bio-hybrid has a enhancing effect on anaerobic fermentation for methane production. In contrast, the methane yield without the piezoelectric bio-hybrid (Comparative Example 1) was 139.652 mL / g COD, showing no significant improvement compared to the conventional anaerobic fermentation method. Furthermore, the maximum methane production potential (P) with the participation of the piezoelectric bio-hybrid was significantly higher. m ) and maximum methane production rate (R m Both were significantly higher than those of non-piezoelectric biological hybrids.

[0089] In summary, the piezoelectric effect is crucial for improving methane yield under anaerobic fermentation, meaning that piezoelectric barium titanate nanoparticles play a decisive role in achieving increased methane yield under anaerobic fermentation.

[0090] Test Example 4

[0091] This test example was used to test the methane yield of the piezoelectric bio-hybrid prepared in Example 2 under anaerobic fermentation. The specific steps were basically the same as those in Test Example 2, except that the piezoelectric bio-hybrid dispersion prepared in Example 2 was used instead of the piezoelectric bio-hybrid dispersion prepared in Example 1, and the addition volume was 0.728 L, which is equivalent to an addition amount of 1.46 g of piezoelectric bio-hybrid.

[0092] Test Example 5

[0093] This test example is used to test the methane yield of anaerobic sludge participating in anaerobic fermentation. The specific steps are basically the same as those in test example 2, except that the anaerobic sludge dispersion prepared in step (2) of example 1 is used instead of the piezoelectric bio-hybrid dispersion prepared in example 1.

[0094] The test results for Test Case 2, Test Case 4, and Test Case 5 are shown in Table 2 and... Figure 3 As shown.

[0095] Table 2. Performance comparison of piezoelectric bio-hybrid anaerobic fermentation of barium titanate nanoparticle dispersion and anaerobic sludge dispersion at different volume ratios

[0096]

[0097] From Table 2 and Figure 3 It can be seen that even if the relative content of barium piezoate particles in the piezoelectric bio-hybrid is increased, the improvement of methane yield under anaerobic fermentation is limited. From the perspective of cost, under the premise that the impact on methane yield under anaerobic fermentation is not significant, the relative content of barium piezoate particles in the piezoelectric bio-hybrid can be appropriately reduced.

[0098] Test Example 6

[0099] This test example was used to examine the effect of stirring speed on the methanogenic performance of piezoelectric bio-hybrids during anaerobic fermentation. The specific steps were basically the same as in Test Example 2, except that the stirring speed was adjusted to 0 rpm, i.e., no stirring.

[0100] Test Example 7

[0101] This test example was used to examine the effect of stirring speed on the methanogenic performance of piezoelectric bio-hybrids during anaerobic fermentation. The specific steps were basically the same as in Test Example 2, except that the stirring speed was adjusted to 200 rpm, i.e., no stirring was performed.

[0102] The test results for Test Case 2, Test Case 6, and Test Case 7 are shown in Table 3 and... Figure 4 As shown.

[0103] Table 3. Comparison of the performance of anaerobic fermentation of piezoelectric bio-hybrids under different stirring speeds

[0104]

[0105] From Table 3 and Figure 4It was found that the methane yield and production rate were relatively high when the stirring speed was 100 rpm. However, when the stirring speed was 200 rpm, the methane yield initially increased over time, reaching a peak of 277.5 mL / g COD at t≈15 h, then decreased and stabilized at 218.963 mL / g COD. This may be because stirring speed enhances the piezoelectric effect; excessively fast stirring speed causes the piezoelectric effect to exceed the tolerance range of some bacterial cells, leading to the inactivation of some cells and reducing the methane yield. Nevertheless, compared with Test Example 1, the methane yield was still increased by 72.31%. When there was no stirring, both the methane yield and production rate decreased. In conclusion, stirring speed significantly affects the methane yield and kinetic characteristics of anaerobic fermentation in piezoelectric biohybrid systems.

[0106] Test Example 8

[0107] This test example was used to test the performance of piezoelectric bio-hybrids in anaerobic fermentation to produce methane under different dosages. The specific steps were basically the same as those in Test Example 2, except that the dosage volume of the piezoelectric bio-hybrid dispersion prepared in Example 1 was 0.728 L, which is equivalent to a dosage of 2 g of piezoelectric bio-hybrids.

[0108] The test results for Test Case 2, Test Case 4, and Test Case 8 are shown in Table 4 and... Figure 5 As shown.

[0109] Table 4. Comparison of anaerobic fermentation performance under different dosages of piezoelectric bio-hybrids

[0110]

[0111] From Table 4 and Figure 5 It can be seen that as the concentration of piezoelectric bio-hybrid increases, the methane yield and P... m R m The dosage of piezoelectric bio-hybrids can be gradually increased, but the effect is not significant. Considering the cost, and assuming that the impact on methane yield under anaerobic fermentation is not significant, the dosage of piezoelectric bio-hybrids can be appropriately reduced.

[0112] The above description provides an illustrative overview of the present invention and its embodiments. This description is not restrictive, and the embodiments shown are merely one example of the invention's implementation. Actual implementations are not limited to these examples. Therefore, if those skilled in the art are inspired by this description and design similar implementations and examples without departing from the spirit of the invention, such designs should fall within the scope of protection of the present invention.

Claims

1. The application of piezoelectric bio-hybrids in the anaerobic fermentation of organic matter to produce methane, characterized in that, The application includes the following steps: Add piezoelectric bio-hybrids to the anaerobic reactor, continuously pump in organic wastewater and stir; The piezoelectric bio-hybrid is composed of barium titanate particles and anaerobic sludge, and the barium titanate particles are piezoelectric.

2. The application of the piezoelectric bio-hybrid according to claim 1 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The hydraulic retention time of the anaerobic reactor was controlled at 12 h to 72 h, the stirring speed at 20 rpm to 180 rpm, and the fermentation temperature at 25℃ to 40℃.

3. The application of the piezoelectric bio-hybrid according to claim 2 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The concentration of the piezoelectric bio-hybrid is 0.1 g / L to 10 g / L, and the concentration of COD in the organic wastewater is 2 to 8 g / L.

4. The application of the piezoelectric bio-hybrid according to claim 2 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The methane yield is greater than or equal to 200 mL / g COD, the maximum methane generation potential is greater than or equal to 200 mL / g COD, and the maximum methane production rate is greater than or equal to 30 mL / (g COD·h).

5. The application of the piezoelectric bio-hybrid according to claim 1 in the anaerobic fermentation of organic matter to produce methane, characterized in that: The mass ratio of the barium titanate particles to the suspended solids in the anaerobic sludge is 1:(2~20).

6. The application of the piezoelectric bio-hybrid according to claim 5 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The method for preparing the piezoelectric bio-hybrid includes the following steps: S1: Add barium titanate particles with piezoelectricity to water and then sonicate to obtain a barium titanate particle dispersion. S2: Add anaerobic sludge to phosphate buffer solution, shake and disperse to obtain anaerobic sludge dispersion; S3: In an inert atmosphere, the anaerobic sludge dispersion is added to the barium titanate particle dispersion while stirring. After stirring evenly, a dispersion containing piezoelectric bio-hybrids is obtained. S4: After the dispersion containing the piezoelectric bio-hybrid is allowed to stand and separate into layers, the supernatant is removed to obtain the piezoelectric bio-hybrid.

7. The application of the piezoelectric bio-hybrid according to claim 6 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The concentration of the barium titanate particle dispersion in S1 is 0.1 g / L to 1 g / L; and / or The MLSS of the anaerobic sludge dispersion in S2 is 1 g / L to 10 g / L; and / or The volume ratio of the barium titanate particle dispersion to the anaerobic sludge dispersion in S3 is (0.1~10):

1.

8. The application of the piezoelectric bio-hybrid according to claim 7 in the anaerobic fermentation of organic matter to produce methane, characterized in that, The ultrasonic treatment time in S1 is 0.5 h to 2 h; and / or The concentration of the phosphate buffer in S2 is 50 mM to 150 mM; and / or The anaerobic sludge dispersion in S3 is added at a rate of 10 mL / min to 60 mL / min, and the stirring speed is 30 rpm to 70 rpm.

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