KR100227186B1 - Anaerobic treatment method of organic wastewater and fermenter using it - Google Patents

Abstract

The present invention relates to an anaerobic treatment method used for the treatment of organic waste liquids, such as manure, and a fermentation tank used therein. Anaerobic treatment method of the present invention comprises the step of fermenting the organic acid production fermentation of organic waste in the first fermentation tank, and the step of transferring the organic waste liquid passed through the organic acid production fermentation step to the second fermentation tank methane production fermentation In the anaerobic treatment method of the organic waste liquid, the transfer of the organic waste liquid from the first fermentation tank to the second fermentation tank is made through the sludge layer formed in the lower portion of the second fermentation tank from the sludge layer formed in the lower portion of the first fermentation tank, The ratio of the hydraulic retention time in the first and second fermentation tanks of the organic waste liquid is about 4:11. In addition, the anaerobic fermentation tank for fermenting the organic waste liquid according to the present invention comprises a fermentation tank separated so that the volume of the organic acid production fermentation portion and the methane production fermentation portion is about 4:11; A diaphragm installed in the fermentation tank to separate the fermentation tank into an organic acid producing fermentation unit and a methane generating fermentation unit, and having a sludge distribution port for distributing sludge under the fermentation tank; A sludge collection unit for collecting sludge at the bottom of the methane production fermentation unit of the fermentation tank; And, it is characterized in that it comprises a sludge discharge port for discharging the sludge of the sludge collection unit to the outside.

Description

Anaerobic treatment of organic waste solution Fermenter used for it

The present invention relates to an anaerobic treatment method used to treat organic waste liquids, such as manure of livestock, and a fermentation tank used therein, and more particularly, to an anaerobic treatment method in which acid-produced fermentation and methane-producing fermentation are performed separately, and use thereof. It relates to a fermenter.

In general, anaerobic fermentation is a wastewater treatment method in which organic wastes such as livestock manure, municipal sewage, agricultural and marine products, food processing by-products and wastewater are decomposed by microorganisms under anaerobic conditions. It is a wastewater treatment method that produces fermentation gas by fermenting organic matter in fermentation tank and decomposing organic matter.

This anaerobic fermentation process can be basically divided into two stages: organic acid production fermentation step and methane production fermentation step.Because the physiological characteristics and nutritional composition of microorganisms in each step are different, The first stage anaerobic fermentation method performed in the same fermenter is impossible to control each stage optimally, although the structure of the fermenter used is simple but the treatment efficiency is low and the concentration of discharged water (BOD, COD, total solids, nitrogen, etc.) High so that subsequent processing is difficult. In addition, anaerobic treatment method and fermenter used for separating organic acid-produced fermentation step and methane-producing fermentation step have been developed to improve these shortcomings, but it is difficult to operate and it is not stable because it is sensitive to load and generation of influent wastewater. In addition, it is not practically used because of its low efficiency.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to simplify the implementation of the organic waste liquid with excellent wastewater treatment efficiency to maintain a stable fermentation despite the change of the influent wastewater It is characterized by providing a miracle treatment method and a fermenter used therein.

Other objects, advantages and novelties of the present invention will be readily apparent from the following description.

1 is a longitudinal sectional view of an anaerobic fermenter according to the present invention,

Figure 2 is a cross-sectional view of the anaerobic fermenter according to the present invention,

Figure 3 is a graph showing the change in sludge layer height after mixing the pig manure in the acid production tank of the anaerobic fermentation tank according to the present invention,

Figure 4 is a schematic process diagram showing the process of using the process including the anaerobic treatment method according to the invention to the manure from the pig side finally used as reprocessed water or discharged or composted.

In order to achieve the above object, according to the present invention, the organic waste liquid produced by the organic fermentation step in the first fermentation tank and the organic waste liquid passed through the organic acid production fermentation step to the second fermentation tank to the methane production fermentation step An anaerobic treatment method of an organic waste liquid is provided. At this time, the transfer of the organic waste liquid from the first fermentation tank to the second fermentation tank is made through the sludge layer formed in the lower portion of the second fermentation tank from the sludge layer formed in the lower portion of the first fermentation tank, the first fermentation tank and the first The ratio of hydraulic residence time in the two fermentation tanks is characterized by about 4:11.

The anaerobic treatment method of the organic waste liquid according to the present invention is a method in which the organic acid producing fermentation step and the methane generating fermentation step are separately performed in order to maximize the characteristics of the anaerobic microorganism as described above. That is, the first fermentation tank in which the organic acid-producing fermentation takes place adjusts the pH of the fermenter to be close to the optimum pH6.3-6.8 of the acid-producing bacteria so that the acid-producing bacteria inhabit. This pH control can increase the load rate of the first fermentation tank of the acid production tank to increase the organic matter that can be decomposed by the acid-producing bacteria to generate the organic acid is active to keep the pH low. On the other hand, in the second fermentation tank in which methane-producing fermentation takes place, the pH of the fermenter is adjusted to be close to the optimum pH7.3-7.5 of methane-producing bacteria so that methane-producing bacteria inhabit. Such pH adjustment is possible by lowering the load rate of the second fermentation tank which is a methane production tank. This pH control is also achieved by simultaneously controlling the hydraulic retention time in each fermenter of the organic waste liquid.

Preferably, the ratio of the hydraulic residence time of the organic waste liquid in the acid production and the methane production tank is about 4:11.

However, the ratio can be changed depending on various factors such as the concentration of organic matter in the waste liquid to be added. For example, a higher concentration of organic matter in the waste to be treated increases the hydraulic retention time in the acid production tank, while a higher carbon content reduces the hydraulic retention time in the acid production tank, while Increase. In addition, when the amount of carbon is relatively lower than that of nitrogen, the hydraulic retention time in the acid production tank is increased. The sum of the hydraulic retention times in the acid and methane production tanks should be approximately 15 days. However, if the concentration of organic matter in the waste liquid is high, it may be longer and shorter if it is low.

Control of the hydraulic residence time as described above is readily apparent to those of ordinary skill in the art based on the description herein.

In the anaerobic treatment method of the organic waste liquid of the present invention, stirring of the waste liquid is important. Acid-producing bacteria in the acid-producing tank decompose organic materials to produce substances such as volatile fatty acids. When organic matter is abundant, acid production is promoted, and the pH is easily lowered to the optimal pH, which lowers the vitality of the acid-producing bacteria. . At this time, the agitation causes the acid diffusion (dilution) generated around the acid-producing bacteria to increase the pH of the strain. In addition, when the nutrient source (organic matter) is consumed and the nutrient source is insufficient, the nutrient source is around the microorganism. There is also the effect of supplying. It also has the effect of preventing the sludge from hardening. Therefore, in the acid production tank, it is necessary to stir the waste liquid, and not only the supernatant liquid but also the sludge layer may be stirred. However, the agitation in the acid production bath is sufficient to be performed intermittently short for the above purpose. This also helps save energy. On the other hand, the wastewater in the methane production tank is divided into supernatant and bud (sludge layer). Methane-producing bacteria live in this sludge layer and methane is most actively produced in this sludge layer. Therefore, when this sludge layer is destroyed, the living base of methane producing bacteria is similar to that of the methane producing bacterium. In other words, if the sludge layer is destroyed, the decomposition rate of organic matter is lowered. In addition, methane-producing bacteria are very long, with generation times of three days to one week, so that frequent stirring results in the outflow of microorganisms. Therefore, in the methane production tank, it is preferable to avoid stirring as much as possible so as not to destroy the sludge layer.

However, slight agitation can increase the decomposition efficiency. That is, by stirring and removing methane, which is an inhibitor of methane-producing bacteria, the vitality of microorganisms can be increased, and nutrients can be supplied mainly by microorganisms by stirring. In addition, in the anaerobic treatment method, the first and second fermentation tanks can be operated continuously.

According to the anaerobic treatment method of the present invention, the waste liquid which has undergone the organic acid-producing fermentation step in the first fermentation tank is transferred to the sludge layer formed in the lower portion of the second fermentation tank via the sludge layer formed in the lower portion of the first fermentation tank. The reason for supplying the waste liquid after the organic acid producing fermentation step in the first fermentation tank to the sludge layer formed at the bottom of the second fermentation tank is that almost all of the methane-producing bacteria in the second fermentation tank are inhabited. This is to allow sufficient fermentation to break down the organic acid as high as possible. In addition, the acid production tank may be stirred not only the supernatant but also the sludge layer, and thus, a sufficiently mixed waste solution may be supplied to the sludge layer formed at the bottom of the methane production tank, but as described above, stirring in the acid production tank is intermittently 2-3 minutes. It is enough to carry out this, and this helps to save energy. In the acid production tank, the agitation is minimized to the required range, and the sludge layer is formed so that the waste liquid after the organic acid-generating fermentation step passes through the sludge layer to generate methane. It is desirable to be transferred to the sludge layer of the bath. In the methane production tank, the supernatant is discharged out of the fermentation tank. The above anaerobic treatment method has the advantage of maintaining the stability of high anaerobic fermentation regardless of the load and properties of the influent wastewater, and other advantages such as increasing the treatment efficiency (BOD, nitrogen) and shortening the treatment period, etc. have.

In addition, the sludge accumulated in the lower portion of the second fermentation tank is discharged out as needed.

The organic waste liquid includes livestock manure, servings, municipal sewage, agricultural and marine products, food processing by-products and their waste water. The organic waste liquid is preferably livestock manure.

After the anaerobic treatment according to the present invention, the waste liquid may be precipitated in the settling tank, divided into the supernatant and the sludge, and then returned to the first fermentation tank. The anaerobic fermentation waste liquid, which has been subjected to the conventional anaerobic fermentation process, is a high concentration of waste liquid having a BOD of about 6000 ppm. This concentration is well above the 3000 ppm BOD, the economic upper limit of aerobic fermentation, a subsequent process of purification. For this reason, wastewater after anaerobic fermentation requires dilution. However, the present invention is a process requiring no dilution water. In other words, the waste liquid undergoing the methane-generating fermentation step of the anaerobic treatment process according to the present invention has a much lower BOD than the waste liquid that has undergone the first stage anaerobic fermentation, but still contains a considerable amount of solids to increase the BOD in the waste liquid. . Therefore, by separating such solids by sedimentation, the solid sludge is added to the first fermentation tank, which is an organic acid fermentation tank, to reduce the BOD of the anaerobic fermentation liquor, and to reduce the load of aerobic fermentation, thereby adding water and diluting it. As a result, anaerobic sludge reduction is effective.

In addition, it is possible to obtain high decomposition efficiency by increasing the acidity of the organic acid fermentation tank to maintain the acidity of the organic acid fermentation tank to increase the acidity of the acid-producing microorganisms. In addition, this process allows the liquid material with a low load in the waste water to have a short hydraulic retention time, while the solids increase the residence time to increase the treatment efficiency of the waste water.

The two-stage anaerobic treatment process may further include other processes before and after the process, and may be used to treat the organic waste liquid. For example, the organic waste liquid subjected to the two-step anaerobic fermentation process may be aerobic fermented in another fermenter. At this time, a portion of the supernatant of the organic acid fermentation tank may be supplied to the aerobic fermentation tank to improve the ratio of carbon and nitrogen in aerobic fermentation. In general, the effluent from the anaerobic fermentation has a high BOD and has a disadvantage in that the decomposition of the carbon source is high but the decomposition of nitrogen is hardly achieved during the anaerobic fermentation decomposition process, which is the same in the two-stage anaerobic fermentation of the present invention.

Such waste liquid is a factor that hinders the efficiency of aerobic fermentation, which is a subsequent process. That is, the concentration of nitrogen is high, but relatively lacking a carbon source that can be processed by microorganisms. However, the supernatant of acid-produced fermentation during the two-stage anaerobic fermentation contains a lot of carbon sources that are easily decomposed, and thus, when mixed with the anaerobic fermentation broth, the shortage of carbon sources can be reduced compared to nitrogen. It can be maximized. In addition, by transferring a portion of the supernatant of the acid-producing fermentation tank to the aerobic fermentation tank, it is possible to reduce the size of the facilities of anaerobic and aerobic fermentation tank, to reduce the fermentation time of anaerobic fermentation, to simplify the process of aerobic fermentation, and to reduce the loading rate of aerobic fermentation. In addition, the acid-produced fermentation has a pH of about 6.3-6.5 and the concentration of the effluent from the methane-producing fermentation stage is about 7.3-7.5, so mixing them can be close to the optimum pH 7 of aerobic fermentation.

On the other hand, a method of improving the aerobic fermentation efficiency by adding a part of the original waste liquid to the anaerobic fermentation waste liquid, which is a conventional method, is also added with the degradable carbohydrate and solids in the raw waste liquid. Although the ratio was improved, the increase in load greatly reduced the efficiency of aerobic fermentation.

In the embodiment of the present invention as described above, the supernatant of the organic acid-producing fermentation tank which is transferred to the aerobic fermentation tank has a relationship of 1: 4 -1: 8 in volume ratio with respect to the organic waste liquid which has undergone the methane production fermentation step introduced into the aerobic fermentation tank. It is preferable in the balance between nitrogen and nitrogen.

According to still another aspect of the present invention, there is provided an anaerobic fermentation tank for fermenting an organic waste liquid, the fermentation vessel being separated such that the volume of the organic acid producing fermentation unit and the methane producing fermentation unit is about 4:11; A diaphragm installed inside the fermentation tank to separate the fermentation tank into an organic acid-producing fermentation section and a methane-producing fermentation section, and having a sludge distribution port therein for distributing sludge; A sludge collection unit for collecting sludge at the bottom of the methane-producing fermentation unit of the fermentation tank; And, it relates to an anaerobic fermentation tank of organic waste liquid, characterized in that it comprises a sludge discharge port for discharging the sludge to the outside of the sludge collection unit.

Hereinafter, an anaerobic fermenter of organic waste liquid according to the present invention will be described with reference to the accompanying drawings for illustrative purposes.

1 is a longitudinal sectional view of the anaerobic fermenter of the present invention. As shown in Figure 1, the anaerobic fermentation tank according to the present invention includes a fermentation tank (1) for fermenting manure; A diaphragm 9 installed in the fermentation tank so as to form the organic acid producing fermentation unit 3 and the methane producing fermentation unit 5 separately and having a sludge distribution port 7 for distributing sludge in the lower portion; A sludge collection unit 11 for collecting sludge at the bottom of the methane-producing fermentation unit of the fermentation tank; It is composed of an anaerobic fermentation tank having a sludge discharge port 13 for discharging the sludge of the sludge collection unit to the outside.

Anaerobic fermentation tank of the present invention can be made of a variety of materials, such as concrete, iron, FRP, the scale can also be produced in various sizes to suit the type and processing capacity of the object to be treated. In addition, the shape can be made in various forms such as a physical surface, a cylindrical shape.

The diaphragm serves to distinguish between the organic acid producing fermentation portion and the methane producing fermentation portion, and also determines the ratio of the hydraulic retention time of the organic acid generating fermentation portion and the methane producing fermentation portion. The pH of the waste liquid from the organic acid producing fermentation and the methane producing fermentation is greatly influenced by the hydraulic retention time, and the success or failure of the two-stage anaerobic fermentation is influenced.

The bottom of the fermentation tank 1 is inclined so that the sludge is smoothly slipped and transported to the sludge collecting part 11 installed on the bottom of the methane producing fermentation part 5.

The diaphragm may be provided with a gas distribution unit 15 for gas flow between the organic acid generating fermentation unit 3 and the methane generating fermentation unit 5 in addition to the sludge distribution port 7 formed in the lower portion.

In addition, a boiler using methane gas generated during anaerobic fermentation is installed outside to maintain the temperature inside the fermentation tank, and a heating pipe or a heating panel may be installed inside the fermentation tank as a hot water circulation heating device.

In addition, in order to mix the contents, the acid pipe is installed where the sludge layer in the lower part of the fermentation tank is formed, and the lower part is blown into the acid pipe by the blower (Blower) to mix the contents.

In addition, the waste liquid inlet 17 for inputting the waste liquid to be treated on the organic acid-producing fermentation side and the supernatant outlet 19 for discharging the supernatant of the methane-producing fermentation may be installed on the side of the fermentation tank. The gas outlet 21 for discharging the gas generated during anaerobic fermentation may be provided. Fermentation gas is supplied to the methane boiler and blower from this gas outlet.

The anaerobic fermentation tank of the present invention can be operated by an intermittent inflow method and a continuous continuous inflow method according to the type of inflow wastewater, and the outflow of the wastewater after anaerobic fermentation can be made at the same time as the wastewater inflow.

As can be seen from the above, the anaerobic fermenter of the present invention is extremely simple in structure, which divides the compartments according to the characteristics of general box-shaped, cylindrical, etc., and creates a tunnel under the partition to move the contents to the part. It is possible to maximize the treatment efficiency by simply separating and operating the organic acid-produced fermentation step and the methane-produced fermentation step as a structure to achieve.

The present invention will be described in more detail with reference to the following Examples. However, the present invention is not limited to the following examples.

EXAMPLE

Example 1-a

This example was performed to compare two stage anaerobic fermentation and conventional one stage anaerobic fermentation. Porcine manure was treated using an anaerobic fermenter with a polyethylene container (actual fermentation capacity) with a capacity of 1 ton of the structure as shown in FIGS. 1 and 2. The characteristics of the used manure are shown in Table 1. The volume ratio of the acid production tank and the methane production tank was 4:11. The operating conditions were that the liquid residence time was 15 days, the hydraulic residence time in the acid production tank was 4 days, and the hydraulic residence time in the methane production tank was 11 days.

Pig manure was divided into 8 groups of 53.3L / day into the acid production tank. And, the supernatant was discharged from the methane production tank 45L per day, which is about 85% of the pig manure input. The remainder was released as steam, methane and sludge. The temperature of the fermenter was maintained at 39 ° C. of the middle temperature fermentation.

Mixing (stirring) of pig manure in the acid production tank and the methane production tank was performed by circulating methane gas produced during anaerobic fermentation using acid pipes installed inside the fermentation tank, and both the acid production tank and the methane production tank were intermittently sludge solidified. It was over a short time of 2-3 minutes only. After stirring the separation of the supernatant and sludge layer, ie the solids took 20-30 minutes. The sludge was discharged out of the methane production tank.

Conventional one-stage anaerobic fermentation experiments used fermenters of the same size and structure as the two-stage anaerobic fermentation, but did not install only short-term diaphragms. The residence time was 15 days. Other conditions were the same as the two stage anaerobic fermentation. The results are shown in Table 2. The results in Table 2 were obtained about 30 days after fermenter operation.

TABLE 1

TABLE 2

Example 1-6

This example was performed to determine the optimal residence time in the acid production tank and the methane production tank during two-stage anaerobic fermentation. Two-stage anaerobic fermentation was used by connecting two units of 8L capacity acrylic container (6L actual fermentation capacity) up and down, and the upper one was used as an acid-producing fermenter and the lower one was used as a methane-producing fermenter. The time was 15 days and the ratio of the residence time in the acid-produced fermentor and the methane fermenter was as Table 3. Therefore, the case where the input time and the flow rate in each fermenter are 4 days in the acid-producing fermentation tank and 11 days in the methane-producing fermenter will be explained as follows.

Acid production tank: input 1.5L / day (6L / 4 days), effluent: about 1.5L / day, methane production tank: input 0.552 / day (6L / 11 days), effluent about 0.522 (day) More than the input from the methane production tank, the rest was discarded. The effluent from the acid production tank was introduced into the sludge layer of the methane production tank, and the supernatant was discharged as treated water from the methane production tank. The temperature of the fermenter was maintained at 39 ° C. of the mid-temperature fermentation as the external tank basic formula. As an auxiliary device, methane gas from the fermenter was stored in the gas collection tank to measure the amount of gas generated, and an acid pipe was installed inside the anaerobic fermenter to circulate the methane gas to stir the inside. Stirring was performed intermittently over a short period of 2-3 minutes in both the acid and methane production tanks. It was the same as used in Example 1-a used.

Conventional one-step anaerobic fermentation was carried out using an acrylic container (actual fermentation capacity 6L) 11 having a volume of 8L. The residence time was 15 days. Other conditions were the same as in the second stage anaerobic fermentation. The results are shown in Table 3. The results in Table 3 were obtained about 30 days after fermenter operation.

TABLE 3

Example 2

This embodiment relates to aerobic fermentation using the supernatant of the acid production tank of the anaerobic fermentation tank.

Pig manure was treated using a two-stage anaerobic fermenter with a polyethylene container (actual fermentation capacity) of 1 ton capacity of the structure as shown in FIGS. 1 and 2. The characteristics of the used manure are shown in Table 4. The volume ratio of the acid production tank and the methane production tank was 4:11. The operating conditions were that the liquid residence time was 15 days, the hydraulic residence time in the acid production tank was 4 days, and the hydraulic residence time in the methane production tank was 11 days.

Pig manure was divided into a total of 55.3L per day into an acid production tank, and about 45L of supernatant was discharged per day from the methane production tank. Some of the discharged supernatant was added to the aerobic fermentation tank with the supernatant extracted from the acid production tank, and the input amount was 40L per day, and this was divided into 8 times. In the acid production tank, the supernatant was transferred to the aerobic fermentation tank in a total of 13.3L per day. Figure 3 shows the change in the sludge height mixed with the contents of the acid production tank. The temperature of the anaerobic fermentation tank was maintained at 39 ° C. Pig manure in the acid production tank and the methane production tank was mixed (stirred) by circulating methane gas produced during anaerobic fermentation using acid pipes installed inside the fermentation tank, and both the acid production tank and the methane production tank were intermittently sludge solidified. It was not enough. After stirring, the supernatant and sludge layer took 20-30 minutes to separate, ie, the solids settle. Over a short period of 2-3 minutes the sludge was discharged out of the methane production tank.

Conventional one-stage anaerobic fermentation experiments used fermenters of the same size and structure as the two-stage anaerobic fermentation, but did not install only diaphragms. The residence time was 15 days. Other conditions were the same as the two stage anaerobic fermentation.

The aerobic fermentation tank was operated in a bottom aeration manner using an 80L acrylic container. The aeration was continued and the air at 20 ° C. was aerated in an amount of 1 L per minute per liter of fermenter work. At this time, the residence time of the liquid substance (HRT) was 1 day and was operated at room temperature (20 ° C). Under the same conditions as above, the fermentation conditions of anaerobic and aerobic were operated for 3 months in the present invention and conventional manner. The results are shown in Table 6.

TABLE 4

TABLE 5

TABLE 6

Example 3

This embodiment relates to the sludge obtained by precipitating the effluent after the two-step anaerobic fermentation to be returned to the acid production tank for reuse.

Pig manure was treated using a two-stage anaerobic fermenter with a polyethylene container (actual fermentation capacity) of 1 ton capacity of the structure as shown in FIGS. 1 and 2. The characteristics of the used manure are shown in Table 1. The volume ratio of the acid production tank and the methane production tank was 4:11. The operating conditions were that the liquid residence time was 15 days, the hydraulic residence time in the acid production tank was 4 days, and the hydraulic residence time in the methane production tank was 11 days. Pig manure was divided into 8 groups of 53.3L / day into the acid production tank. And, the supernatant was discharged from the methane production tank 45L per day, which is about 85% of the pig manure input. The remainder was released as steam, methane and sludge. The temperature of the fermenter was maintained at 39 ° C. of mesophilic fermentation.

Mixing (stirring) of pig manure in the acid production tank and the methane production tank was performed by circulating methane gas produced during anaerobic fermentation using acid pipes installed inside the fermentation tank, and both the acid production tank and the methane production tank were intermittently sludge solidified. It did so over a short period of 2-3 minutes only. After stirring it took 20-30 days for separation of the supernatant and sludge layer, ie the solids settling. Over a short period of 2-3 minutes the sludge was discharged out of the methane production tank.

The supernatant discharged from the methane production tank was precipitated in the sedimentation tank to obtain sludge, and 5.3 L, corresponding to about 10% of the manure that is added to the acid production tank in one day, was returned to the acid production tank once. Table 7 shows the results of treating pig manure by operating the fermenter for three months in the same way as above.

TABLE 7

Example 4

This example is an example showing the pre-process until the pig manure discharged from the barn is passed through the two-step anaerobic fermentation process of the present invention and finally used as recycled water or used as a discharge or compost. 4 shows a flow chart of the process. The configuration of the process is described in more detail as follows.

(1) separator

Device for sorting coarse particles

(2) Anaerobic two-stage fermentation tank (acid producing fermentation tank, methane production tank) one stage: the structure shown in Figure 1,

Acid-producing fermenter: Retention time (HRT) 4 days

Methane-generating fermenter: 11 days of loading rate (HRT)

-Warmer: Hot water circulation system (combustion of generated methane gas to obtain hot water, internal fermenter gas, hot water circulation method)

-Contents mixing device: Gas circulation system (Blows the generated methane gas into the acid pipe installed in the lower part of the fermenter with the pump to mix the contents)

Methane gas storage device

Desulfurization system: A device for removing hydrogen sulfide contained in methane

(3) anaerobic fermentation tank waste liquor sedimentation tank-2 units

-Primary sedimentation tank: load rate (HRT)-0.15 days

-Second sedimentation tank: load rate (HRT)-0.5 days

(4) 2 aerobic fermentation tanks

First fermentation: 1 day load rate (HRT)

2nd aerobic fermentation: 2 days of loading rate (HRT)

(5) aerobic waste liquid sedimentation tank

Load rate (HRT) 1 day

(6) filtration tank

Load rate (HRT) 1 day

(7) Other equipment: input device, conveying device, discharge device

The treatment process system of this example was manufactured on a pilot scale and automated to use in experiments. The configuration of this system is the same as the above technique, and the size of the anaerobic fermenter (Acidogenic fermenter + Methanogenic fermenter, Acidogenic stage: Methanogenic stage volume ratio = 4:11) is 800L. And other devices were manufactured and used to scale. The components of pig sludge used in this experiment are shown in Table 8, and the conditions of the experimental process are shown in Table 9. The experiment was conducted for 6 months. Table 10 shows the treatment efficiency of this process.

Table 8

TABLE 9

TABLE 10

As can be seen from the above, the anaerobic fermentation tank of the present invention has an extremely simple structure and is easy to operate, and the anaerobic treatment method of the organic waste liquid according to the present invention using such a fermentation tank is also easy to implement, and the load of influent wastewater. Regardless of the properties and properties, it maintains high fermentation stability and has excellent treatment efficiency.

Claims (18)

(Correction) In the anaerobic treatment method of organic waste liquid comprising the step of organic acid production and fermentation of organic waste liquid in the first fermentation tank, and the step of transferring the organic waste liquid passed through the organic acid production fermentation step to the second fermentation tank methane production fermentation The transfer of the organic waste liquid from the first fermentation tank to the second fermentation tank is performed through the sludge layer formed at the bottom of the second fermentation tank from the sludge layer formed at the bottom of the first fermentation tank, and the first fermentation tank and the first fermentation tank of the organic waste solution. The ratio of hydraulic retention time in the two fermentation tanks is about 4:11. (Correction) The anaerobic treatment method according to claim 1, wherein the first fermentation tank and the second fermentation tank are operated continuously. (Correction) The anaerobic treatment method of organic waste liquid according to claim 1, wherein the sludge accumulated at the bottom in the second fermentation tank is discharged outward. (Correction) The anaerobic treatment method of organic waste liquid according to claim 1, wherein the sludge obtained by precipitating the organic waste liquid passed through the methane production fermentation step is returned to the first fermentation tank. (Correction) The anaerobic treatment method of organic waste liquid according to any one of items 1 to 3 and 4, wherein the organic waste liquid is manure. (Correction) The anaerobic treatment method according to claim 5, wherein the manure is a human. (Correction) The anaerobic treatment method according to claim 5, wherein the manure is from livestock. (Correction) The anaerobic treatment method according to claim 7, wherein the livestock manure is a pig. (Correction) The method according to any one of claims 1 to 3 and 4, wherein the anaerobic treatment method of the organic waste liquid further comprises aerobic fermentation of the organic waste liquid having undergone the methane production fermentation step in a third fermentation tank. Anaerobic treatment method of organic waste liquid, characterized in that. (Correction) The anaerobic treatment method of organic waste liquid according to claim 9, wherein a part of the supernatant of the first fermentation tank is supplied to the third fermentation tank. (Correction) The method according to claim 9, wherein the supernatant of the third fermentation tank transferred to the third fermentation tank has a relationship of 1: 4 -1: 8 in volume ratio with respect to the organic waste liquid which has undergone the methanogenic fermentation step (3). The anaerobic treatment method of organic waste liquid which uses (Correction) The method for anaerobic treatment of organic waste liquid according to claim 9, wherein the sum of the hydraulic retention times in the first and second fermentation tanks of the organic waste liquid is approximately 15 days. (Correction) in the anaerobic fermentation tank for fermenting organic waste liquid, A fermentation tank separated so that the volume of the organic acid producing fermentation section and the methane generating fermentation section is about 4:11; A diaphragm installed in the fermentation tank to separate the fermentation tank into an organic acid-producing fermentation section and a methane-producing fermentation section, and having a sludge distribution port therein for distributing sludge; A sludge collection unit for collecting sludge at the bottom of the methane-producing fermentation unit of the fermentation tank; And a sludge discharge port for discharging the sludge from the sludge collecting unit to the outside. (Correction) The anaerobic fermentation tank of organic waste liquid according to claim 13, wherein the bottom of the fermentation tank is inclined so that the sludge slides to the sludge collection unit. (Correction) The anaerobic fermentation tank of organic waste liquid according to claim 13, wherein the diaphragm is provided with a gas distribution port for distributing gas between the organic acid producing fermentation unit and the methane generating fermentation unit. (Correction) The anaerobic fermentation tank of organic waste liquid according to claim 13, wherein a heating device for heating the contents is provided inside the fermentation tank. (Correction) The anaerobic fermentation tank of organic waste liquid according to claim 16, wherein the heating device is a hot water circulation pipe or panel. (Correction) The anaerobic fermentation tank of organic waste liquid according to claim 13, wherein an acid pipe for mixing the contents is provided in the lower part of the fermentation tank.