JP6689627B2 - Anaerobic wastewater treatment equipment - Google Patents

Description

  The present invention relates to an anaerobic wastewater treatment device.

  As a method of treating wastewater containing fats and oils, for example, wastewater containing fats and oils is separated into oil and water by pressure flotation to separate sludge containing fats and oils and pressure flotation treated water, and then pressure flotation treated water is preferable. A method is known in which methane fermentation by methane bacteria is applied to the decomposition of sludge containing fats and oils by subjecting to air treatment and / or high-load anaerobic treatment (Patent Document 1). According to the method of Patent Document 1, it is said that the oil / fat in the wastewater containing the oil / fat is separated and the anaerobic treatment is applied to the decomposition of the oil / fat-containing sludge after the separation, whereby the wastewater containing the oil / fat can be purified with high efficiency. ing.

JP, 2006-95377, A

  On the other hand, the method of Patent Document 1 may cause problems such as generation of odor due to pressure floating and the need for a space for introducing the pressure floating tank. In addition, fats and oils have a problem that they are not easily biodegraded under anaerobic treatment conditions. In particular, higher fatty acids produced by the hydrolysis of ester bonds in fats and oils (triglycerides) are less likely to be reduced to a low molecular weight by β-oxidation under anaerobic treatment conditions, and lower fatty acids that can be decomposed to methane by methane bacteria are produced. There is a problem that it is difficult. Further, there is a problem that scum occurs due to the accumulation of higher fatty acids in the tank.

  Therefore, it is an object of the present invention to provide an anaerobic wastewater treatment device having an increased decomposition efficiency of higher fatty acids in anaerobic treatment.

  That is, the present invention introduces wastewater containing fats and oils, an acid production tank that decomposes fats and oils by treated bacteria to produce primary treated water containing acid, and introduces primary treated water, and methane ferments with treated bacteria. A reaction tank for producing secondary treated water, and a return means for returning the treated bacteria discharged from the reaction tank to the acid production tank and / or a hydrogen partial pressure reduction means for reducing the hydrogen partial pressure in the acid production tank. Provided is an anaerobic wastewater treatment device.

  According to the anaerobic wastewater treatment device of the present invention, it is possible to increase the decomposition efficiency of higher fatty acids in anaerobic treatment.

  The present inventors presume the reason why the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased by the anaerobic wastewater treatment apparatus according to the present invention as follows. First, in the present invention, by having a returning means for returning the treated bacteria discharged from the reaction tank to the acid generation tank, the decomposition of oil and fat and higher fatty acids by the returned treated bacteria is promoted in the acid generation tank. Furthermore, it is considered that the returned treated bacteria can reduce the hydrogen partial pressure in the acid generation tank, so that β-oxidation of higher fatty acids in the acid generation tank is promoted.

  Further, in the present invention, by having a hydrogen partial pressure reducing means for reducing the hydrogen partial pressure in the acid production tank, since the hydrogen partial pressure can be reduced, β oxidation of higher fatty acids is promoted. The inventors speculate.

  Further, according to the anaerobic wastewater treatment device of the present invention, the wastewater containing oil and fat is not separated into oil and water by pressure flotation, and odor is generated and a space accompanying the introduction of the pressure flotation tank is required. There are no such problems.

  The returning means may include a collecting unit that collects the discharged treated bacteria.

  The hydrogen partial pressure reducing means may be a dominating means for dominating hydrogen-utilizing bacteria in the acid-producing tank, and the dominating means may be used in the acid-producing tank containing hydrogen-utilizing bacteria. It may be a means for varying the load on the treated bacterium or a means for supplying a substance that inhibits the activity of the treated bacterium in the acid generator other than the bacterium utilizing hydrogen.

  ADVANTAGE OF THE INVENTION According to this invention, the anaerobic wastewater treatment apparatus which improved the decomposition efficiency of the higher fatty acid in anaerobic treatment can be provided.

It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 3rd Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows an example of the collection part in the anaerobic wastewater treatment equipment which concerns on 5th Embodiment of this invention. It is a schematic diagram which shows an example of the collection part in the anaerobic wastewater treatment equipment which concerns on 6th Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 7th Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 8th Embodiment of this invention. It is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 9th Embodiment of this invention. It is a figure which shows the breakdown of the oil component and its decomposition product in the acid production tank which concerns on each embodiment of this invention.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings in some cases, but the present invention is not limited to these embodiments.

[Anaerobic wastewater treatment equipment]
The anaerobic wastewater treatment apparatus according to the present embodiment introduces wastewater containing oil and fat, and an acid generation tank that decomposes the oil and fat by the treating bacteria to generate primary treated water containing acid, and introduces the primary treated water, and treats it. A reaction tank for producing secondary treated water by methane fermentation with bacteria, and reducing the hydrogen partial pressure in the returning means and / or the acid generating tank for returning the treated bacteria discharged from the reaction tank to the acid generating tank It has a hydrogen partial pressure reducing means.

  In the present embodiment, the anaerobic treatment is a treatment of hydrolyzing fats and oils to produce higher fatty acids, a treatment of β-oxidizing higher fatty acids to produce lower fatty acids, and converting lower fatty acids into methane and carbon dioxide by methane fermentation or the like. This is the process to do. Here, the higher fatty acid refers to, for example, a fatty acid having 12 or more carbon atoms, and the lower fatty acid refers to, for example, a fatty acid having 2 to 4 carbon atoms such as acetic acid.

  In addition, in the present embodiment, the acid formation means a treatment of hydrolyzing fats and oils to produce higher fatty acids and a treatment of β-oxidizing higher fatty acids to produce lower fatty acids in some cases. Note that the present inventors have confirmed that wastewater containing oil and fat is decomposed by the treating bacteria in the acid production tank. Fig. 10 shows the results of measuring the content of fats and oils (triglycerides), higher fatty acids and lower fatty acids before and after culturing for 72 hours after adding fats and oils, treated bacteria and a medium to a nitrogen-substituted test tube. Indicates. According to FIG. 10, by the returning means for returning the treated bacteria discharged from the reaction tank to the acid generation tank and / or the hydrogen partial pressure reduction means for reducing the hydrogen partial pressure in the acid generation tank, It can be seen that the proportion can be increased.

  The treated bacterium may be an anaerobic bacterium suitable for anaerobic treatment, for example, methanobacterium such as methanobacterium, methanospirillum, methanosarcina, sulfate-reducing bacterium such as desulfovibrio, clostridium, syntrophomonas and the like. Can be mentioned. The treated bacterium may be used alone, but is usually used in a mixed form of a plurality of types. The method for adding the treated bacterium to the acid generation tank and the reaction tank is not particularly limited, and the treated bacterium may be added as it is, or a granular sludge layer containing the treated bacterium may be added, and the treated bacterium is immobilized on the carrier. Treated bacteria may be added. Moreover, the structures of the treated bacteria contained in the acid production tank and the reaction tank may be the same or different.

<First Embodiment>
FIG. 1 is a schematic diagram showing an anaerobic wastewater treatment device according to a first embodiment of the present invention. The anaerobic wastewater treatment device 100 shown in FIG. 1 includes an acid generation tank 10, a reaction tank 20, a return means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, and a line L1 connecting these. To L5.

  The wastewater containing fats and oils is introduced into the acid production tank 10 through the line L1 and is acid-treated by the treatment bacteria contained in the acid production tank 10 to produce primary treated water. The primary treated water contains at least a lower fatty acid, but may also contain other higher fatty acids and untreated fats and oils. Subsequently, the primary treated water is introduced into the reaction tank 20 through the line L2 and is subjected to methane fermentation by the treating bacteria contained in the reaction tank 20 to generate a gas 23 containing methane and carbon dioxide as main components, Generate secondary treated water. Further, the treated bacteria contained in the reaction tank 20 may form a granule sludge layer 22, for example. A settler 21 may be provided inside the reaction tank 20. The generated gas 23 is discharged outside the device (not shown). The secondary treated water is discharged to the outside of the reaction tank 20 through the line L3 and introduced into the returning means 30. The secondary treated water contains a part of the treated bacteria contained in the reaction tank 20. At least a part of the treated bacteria is recovered by the returning means 30, and the treated bacteria are returned to the acid production tank 10 via the line L4. The valve V1 may be provided in the line L4. The treated bacteria returned to the acid production tank 10 may be returned as granules when the granule sludge layer 22 is formed in the reaction tank 20, or separated by ultrasonic waves, spraying, pulverization in a pump, or the like. It may be returned in a fixed state, or may be returned in a state of being immobilized on a carrier. In order to immobilize the treated bacterium on the carrier, it may be cultured for a certain period of time in a culture medium containing the carrier. The rest of the secondary treated water introduced into the returning means 30 is discharged to the outside of the device through the line L5.

  As described above, in the anaerobic wastewater treatment device 100, by providing the returning means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, the amount of treated bacteria in the acid generation tank 10 increases, The decomposition of fats and oils and higher fatty acids in the acid production tank 10 (and the reaction tank 20 in some cases) is promoted. In particular, the amount of bacteria (such as methanobacterium) that uses hydrogen is increased, and the hydrogen partial pressure in the acid production tank 10 (and the reaction tank 20 in some cases) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

(Second to fourth embodiments)
2 to 4 are schematic diagrams showing an anaerobic wastewater treatment apparatus according to second to fourth embodiments of the present invention, which includes an acid generation tank and a reaction tank, and show hydrogen partial pressure in the acid generation tank. It has means for reducing hydrogen partial pressure. The hydrogen partial pressure reducing means may be a dominating means for making bacteria utilizing hydrogen in the acid production tank dominant. Making the bacteria utilizing hydrogen dominate means that the bacteria utilizing hydrogen become the dominant species in the whole treated bacteria. The dominating means for dominating hydrogen-utilizing bacteria in the acid generator may be, for example, a means for varying the load on the treated bacteria in the acid-producing tank and the reaction tank containing the hydrogen-utilizing bacteria. Alternatively, it may be a means for supplying a substance that inhibits the activity of the treated bacteria in the acid production tank and reaction tank other than the bacteria that utilize hydrogen. Here, examples of the bacteria utilizing hydrogen include hydrogen-utilizing methane bacteria such as methanobacterium and methanospirillum, and hydrogen-utilizing sulfate reducing bacteria such as desulfovibrio.

  As a substance that inhibits the activity of the acid-producing tanks other than the bacteria that use hydrogen and the treatment bacteria in the reaction tank, the substances that act on the acid-producing tanks other than the bacteria that use hydrogen and the treated bacteria themselves in the reaction tank are not active. Examples include substances to be suppressed, substances that inhibit the activity of treated bacteria in acid-producing tanks and reaction tanks other than bacteria that use hydrogen by setting the pH of the reaction solution in the acid-producing tank and reaction tank to an alkaline environment. . Examples of the substance that acts on the acid-producing tank other than the bacteria using hydrogen and the treated bacteria themselves in the reaction tank to suppress the activity include methanol, sulfur compounds, ammonium nitrogen, and ammonia. In addition, as a substance that inhibits the activity of the treated bacteria in the acid generation tank and the reaction tank other than the bacteria that use hydrogen by setting the pH of the reaction liquid in the acid generation tank and the reaction tank in an alkaline environment, there is hydroxylation. Examples thereof include alkaline substances such as sodium and potassium hydroxide. When using an alkaline substance, during the reaction of decomposing fats and oils to generate an acid, the activity of treated bacteria other than the bacteria using hydrogen is efficiently suppressed while suppressing the inhibition of the activity of bacteria using hydrogen. From the viewpoint of inhibition of pH, it is preferable to control the pH of the reaction solution to 7.5 to 8.0, and more preferable to control it to 7.5 to 7.8.

  FIG. 2 and FIG. 3 are schematic diagrams showing an anaerobic wastewater treatment device in which the dominating means is a means for varying the load on the treated bacteria in the acid production tank and the reaction tank containing bacteria that utilize hydrogen ( 2nd Embodiment and 3rd Embodiment). Giving load fluctuations to the treated bacteria in the acid generator tank and reaction tank containing hydrogen-using bacteria means that the treated bacteria containing hydrogen-using bacteria process organic substances such as fats and oils processed per unit time / unit volume. It means changing the amount, for example, increasing and decreasing the amount of organic substances such as fats and oils, and repeating these. The present inventors have confirmed that methanobacterium can be dominated by giving load fluctuations to treated bacteria.

<Second Embodiment>
An anaerobic wastewater treatment device 200 shown in FIG. 2 stores an acid generation tank 10, a reaction tank 20, a high-concentration raw water tank 40 for storing wastewater containing high-concentration oil and fat, and a wastewater containing low-concentration oil and fat. A low-concentration raw water tank 50 and lines L2 and L6 to L10 connecting these tanks are provided.

  The wastewater containing oil and fat is divided into wastewater containing high-concentration oil and fat and wastewater containing low-concentration oil and fat, and introduced into the high-concentration raw water tank 40 and the low-concentration raw water tank 50 via lines L6 and L8, respectively. . The wastewater containing the high-concentration oil and fat and the wastewater containing the low-concentration oil and fat stored in the high-concentration raw water tank 40 and the low-concentration raw water tank 50, respectively, are introduced into the acid generation tank 10 via lines L7 and L9, respectively. . At this time, the lines L7 and L9 are provided with valves V2 and V3 as switching means, respectively, and by switching the valves V2 and V3, the oil and fat concentration in the raw water can be changed. For example, when introducing wastewater containing high-concentration oil and fat into the acid generation tank 10, the valve V2 may be opened and the valve V3 may be closed. Wastewater containing high-concentration or low-concentration oil and fat introduced into the acid generation tank 10 is subjected to acid treatment by the treatment bacteria contained in the acid generation tank 10 to generate primary treated water. The primary treated water contains at least a lower fatty acid, but may also contain other higher fatty acids and untreated fats and oils. Subsequently, the primary treated water is introduced into the reaction tank 20 through the line L2, and is subjected to methane fermentation by the treating bacteria contained in the reaction tank 20 to generate a gas 23 containing methane and carbon dioxide as main components, Generate secondary treated water. The treated bacteria contained in the reaction tank 20 may form a granule sludge layer 22. The generated gas is released outside the device (not shown). The secondary treated water is discharged via the line L10.

<Third Embodiment>
The anaerobic wastewater treatment device 300 shown in FIG. 3 includes an acid generation tank 10, a reaction tank 20, a raw water tank 60 for storing wastewater containing oil and fat, and lines L2, L5, and L11 to L13 connecting these. Prepare

  The wastewater containing oil and fat is introduced into the raw water tank 60 via the line L11. The wastewater containing the oil and fat stored in the raw water tank 60 is introduced into the acid generation tank 10 through the line L12. The wastewater containing oil and fat introduced into the acid generation tank 10 is acid-treated by the treatment bacteria contained in the acid generation tank 10 to generate primary treated water. The primary treated water contains at least a lower fatty acid, but may also contain other higher fatty acids and untreated fats and oils. Subsequently, the primary treated water is introduced into the reaction tank 20 through the line L2 and generates a gas 23 containing methane and carbon dioxide as main components, which is methane-fermented by the processing bacteria contained in the reaction tank 20. Generate secondary treated water. The treated bacteria contained in the reaction tank 20 may form a granule sludge layer 22. The generated gas 23 is discharged outside the device (not shown). The secondary treated water is introduced so that at least a part thereof joins the line L12 via the line L13. At this time, the line L13 is provided with the valve V4, and the oil / fat concentration in the raw water can be changed by controlling the opening / closing of the valve V4. For example, the valve V4 may be opened when the concentration of the oil / fat in the wastewater containing the oil / fat introduced into the acid generation tank 10 is reduced. The rest of the secondary treated water is discharged via the line L5.

  Note that the line L13 does not necessarily have to be introduced so as to join the line L12 as described above, and the purpose of adjusting the concentration of the oil / fat in the wastewater containing the oil / fat introduced into the acid generation tank 10 can be achieved. If present, for example, it may be introduced so as to join the raw water tank 60. Further, the line L13 is not required to be connected to the line L5 as long as it can supply water containing no oil and fat to the raw water, and may be connected to a supply port for industrial water or the like.

  As described above, in the anaerobic wastewater treatment devices 200 and 300, by changing the oil / fat content of the wastewater containing the oil / fat introduced into the acid generation tank 10, the treated bacteria including hydrogen-utilizing bacteria can be obtained. On the other hand, by giving a load variation, bacteria (such as methanobacterium) using hydrogen are dominated, and the hydrogen partial pressure of the acid production tank 10 (and the reaction tank 20) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

<Fourth Embodiment>
FIG. 4 is a schematic diagram showing an anaerobic wastewater treatment device in which the dominating means is a means for supplying substances that mainly inhibit the activity of the treated bacteria in the acid-producing tank and the reaction tank other than the bacteria using hydrogen It is a figure. By mainly inhibiting the activity of the treated bacteria other than the hydrogen-using bacteria, the hydrogen-using bacteria are relatively dominated, and the hydrogen partial pressure in the acid production tank and the reaction tank is reduced.

  The anaerobic wastewater treatment device 400 shown in FIG. 4 includes an acid generation tank 10, a reaction tank 20, an inhibitor supply tank 70, and lines L1 to L2, L5, and L14 connecting these.

  The wastewater containing fats and oils is introduced into the acid production tank 10 through the line L1 and is acid-treated by the treatment bacteria contained in the acid production tank 10 to produce primary treated water. At this time, a substance that mainly inhibits the activity of treated bacteria other than the bacteria that use hydrogen is supplied from the inhibitor supply tank 70 to the acid generation tank 10 via the line L14. The valve V5 may be provided in the line L14. The primary treated water contains at least a lower fatty acid, but may also contain other higher fatty acids and untreated fats and oils. Subsequently, the primary treated water is introduced into the reaction tank 20 through the line L2 and is subjected to methane fermentation by the treating bacteria contained in the reaction tank 20 to generate a gas 23 containing methane and carbon dioxide as main components, Generate secondary treated water. The treated bacteria contained in the reaction tank 20 may form a granule sludge layer 22. The generated gas 23 is discharged outside the device (not shown). The secondary treated water is discharged through the line L5.

  As described above, in the anaerobic wastewater treatment device 400, by introducing a substance that inhibits the activity of treated bacteria other than the bacteria that use hydrogen into the acid generation tank 10, the bacteria that use hydrogen eventually dominate. And the hydrogen partial pressure of the acid generation tank 10 (and the reaction tank 20) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

(Fifth and sixth embodiments)
In the anaerobic wastewater treatment device 100 according to the first embodiment described above, it is preferable that the returning means 30 includes a collecting unit that collects the treated bacteria to be discharged. Since the returning means 30 includes the collecting part for collecting the treated bacteria, the treated bacteria contained in the secondary treated water can be efficiently collected, so that the amount of the treated bacteria in the acid generation tank 10 can be more effectively increased. Can be increased. Examples of the collection unit include a U-shaped valve and a buffer tank. FIG. 5 and FIG. 6 are schematic diagrams showing the collection unit in the anaerobic wastewater treatment device according to the first embodiment of the present invention.

<Fifth Embodiment>
FIG. 5 is a schematic diagram showing the U-shaped valve 31, and the valve V6 is provided at the bottom of the U-shaped pipe. In the anaerobic wastewater treatment device 100, the treated bacteria contained in the secondary treated water supplied through the line L3 is collected by the U-shaped valve 31 and returned to the acid production tank 10 through the line L4. The secondary treated water from which the treated bacteria have been separated may be discharged, for example, via the line L5, or may be returned together with the treated bacteria to the acid production tank 10 via the line L4.

<Sixth Embodiment>
FIG. 6 is a schematic diagram showing the buffer tank 32. The treated bacteria contained in the secondary treated water supplied via the line L3 are precipitated and collected in the buffer tank 32, and are returned to the acid production tank 10 via the line L4. The secondary treated water from which the treated bacteria have been separated may be discharged, for example, via the line L5, or may be returned together with the treated bacteria to the acid production tank 10 via the line L4.

<Seventh Embodiment>
FIG. 7: is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 7th Embodiment of this invention. The anaerobic wastewater treatment device 700 shown in FIG. 7 includes an acid generation tank 10, a reaction tank 20, a return means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, and a high-concentration oil and fat. A high-concentration raw water tank 40 for storing drainage, a low-concentration raw water tank 50 for storing drainage containing low-concentration oil and fat, and lines L2 to L9 connecting these.

  In the anaerobic wastewater treatment device 700, by providing the returning means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, the amount of treated bacteria in the acid generation tank 10 increases, and the acid generation tank 10 is increased. (And in some cases, the reaction tank 20) accelerates the decomposition of fats and oils and higher fatty acids. In particular, the amount of bacteria (such as methanobacterium) that uses hydrogen is increased, and the hydrogen partial pressure in the acid production tank 10 (and the reaction tank 20 in some cases) is reduced. In addition, by changing the oil / fat content of wastewater containing oil / fat introduced into the acid generation tank 10, load fluctuations are applied to treated bacteria including bacteria that utilize hydrogen, resulting in bacteria that use hydrogen. Is dominated, and the hydrogen partial pressure of the acid production tank 10 (and the reaction tank 20) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

<Eighth Embodiment>
FIG. 8: is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 8th Embodiment of this invention. The anaerobic wastewater treatment device 800 shown in FIG. 8 stores the acid generation tank 10, the reaction tank 20, the return means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, and the wastewater containing oil and fat. The raw water tank 60 and the lines L2 to L5 and L11 to L13 connecting them are provided.

  In the anaerobic wastewater treatment device 700, by providing the returning means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, the amount of treated bacteria in the acid generation tank 10 increases, and the acid generation tank 10 is increased. (And in some cases, the reaction tank 20) accelerates the decomposition of fats and oils and higher fatty acids. In particular, the amount of bacteria (such as methanobacterium) that uses hydrogen is increased, and the hydrogen partial pressure in the acid production tank 10 (and the reaction tank 20 in some cases) is reduced. In addition, by changing the oil / fat content of wastewater containing oil / fat introduced into the acid generation tank 10, load fluctuations are applied to treated bacteria including bacteria that utilize hydrogen, resulting in bacteria that use hydrogen. Is dominated, and the hydrogen partial pressure of the acid production tank 10 (and the reaction tank 20) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

<Ninth Embodiment>
FIG. 9: is a schematic diagram which shows the anaerobic wastewater treatment equipment which concerns on 9th Embodiment of this invention. The anaerobic wastewater treatment device 900 shown in FIG. 9 includes an acid generation tank 10, a reaction tank 20, a return means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, and an inhibitor supply tank 70. , And lines L1 to L5 and L14 connecting these.

  In the anaerobic wastewater treatment device 900, by providing the returning means 30 for returning the treated bacteria discharged from the reaction tank 20 to the acid generation tank, the amount of treated bacteria in the acid generation tank 10 is increased, and the acid generation tank 10 is increased. (And in some cases, the reaction tank 20) accelerates the decomposition of fats and oils and higher fatty acids. In particular, the amount of bacteria (such as methanobacterium) that uses hydrogen is increased, and the hydrogen partial pressure in the acid production tank 10 (and the reaction tank 20 in some cases) is reduced. By introducing a substance that inhibits the activity of treated bacteria other than hydrogen-using bacteria from the inhibitor supply tank 70 into the acid-producing tank 10, as a result, bacteria that use hydrogen are dominated, and acid-producing bacteria are produced. The hydrogen partial pressure of the tank 10 (and the reaction tank 20) is reduced. As a result, β-oxidation of higher fatty acids is promoted, and the decomposition efficiency of higher fatty acids in anaerobic treatment can be increased.

  100, 200, 300, 400, 700, 800, 900 ... Anaerobic wastewater treatment device, 10 ... Acid production tank, 20 ... Reaction tank, 21 ... Setter, 22 ... Granule sludge layer, 23 ... Gas, 30 ... Returning means , 31 ... U-shaped valve, 32 ... Buffer tank, 40 ... High concentration raw water tank, 50 ... Low concentration raw water tank, 60 ... Raw water tank, 70 ... Inhibitor supply tank, L1, L2, L3, L4, L5, L6 L7, L8, L9, L10, L11, L12, L13, L14 ... Lines, V1, V2, V3, V4, V5 ... Valves.

Claims (1)

A wastewater containing fats and oils is introduced to decompose the fats and oils with a first treatment bacterium containing hydrogen-utilizing methane bacteria and at least one selected from Clostridium and Syntrophomonas to produce primary treated water containing acid. An acid production tank for production,
A reaction tank which introduces the primary treated water and methane-ferments with a second treated bacterium containing a hydrogen-utilizing methane bacterium to produce secondary treated water;
A hydrogen partial pressure reducing means for reducing the hydrogen partial pressure prior hexane production tank,
An anaerobic wastewater treatment device, wherein the hydrogen partial pressure reducing means is a dominant means for making the hydrogen-utilizing methane bacteria dominant in the acid generation tank.

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