KR20230075377A - Method and apparatus for treating high-concentration waste water generated during hydrothermal carbonization of livestock manure - Google Patents

Abstract

The present invention relates to a method and an apparatus for efficiently and economically treating organic matter and nitrogen contained in wastewater generated in a hydrothermal carbonization process of livestock manure and an apparatus therefor, (1) converting high-concentration wastewater generated during hydrothermal carbonization of livestock manure into anaerobic digestion tank raw water A first anaerobic digestion step of anaerobic digestion by supplying to the first anaerobic digestion tank through the inlet pipe; (2) a second anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the first anaerobic digestion step to a second anaerobic digestion tank for anaerobic digestion; (3) a third anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the second anaerobic digestion step to a third anaerobic digestion tank for anaerobic digestion; (4) In the third anaerobic digestion step, high-concentration wastewater generated during hydrothermal carbonization of anaerobically digested livestock is supplied to an anaerobic microbial separation and stabilization tank to separate anaerobic microorganisms and stabilize by accumulating in high concentration at the bottom of the anaerobic microbial separation and stabilization tank Separation and stabilization of anaerobic microorganisms; (5) The anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step are returned to the first anaerobic digestion tank through the anaerobic microorganism internal return pipe, and high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which organic matter is removed is anaerobic treated water ammonia stripping An anaerobic microorganism transport and ammonia stripping reaction step of supplying ammonia to a stripping reactor through an inlet pipe to the reactor and subjecting the ammonia to stripping; And (6) ammonia-removed water return and discharge step of returning high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which ammonia is removed in the anaerobic microorganisms return and ammonia stripping reaction step to the first anaerobic digestion tank through the ammonia-remove water internal return pipe It relates to a method for treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure containing ; and an apparatus for performing the method.

Description

Method and apparatus for treating high-concentration waste water generated during hydrothermal carbonization of livestock manure}

In the present invention, livestock manure such as pig manure and cow manure is put into a hydrothermal carbonization tank, which is a pressure reactor, and hydrothermal carbonization is performed using a hydrothermal carbonization process, which is a wet carbonization process. Wastewater is separated from solid-liquid, solid carbide is used as fuel, etc., and wastewater containing high-concentration organic matter and ammonia, which are separated liquid, is treated by anaerobic microorganisms, which is a process to remove organic matter, and ammonia stripping, which is a process to remove high-concentration ammonia. It relates to a method and apparatus for efficiently and economically treating organic substances and ammonia contained in wastewater using a process.

Livestock manure is a typical livestock waste, and a method of converting it into energy is to manufacture it with solid fuel, and the solid fuel conversion method includes a drying process, a carbonization process, a torrefaction process, and a hydrothermal carbonization process.

The carbonization and torrefaction processes have disadvantages in that moisture of the reactants must be removed and an oxygen-blocked atmosphere must be created by injecting an inert gas (argon, nitrogen, helium, etc.) into the hydrothermal carbonization reactor.

In addition, the drying process is a simple and general method that can be performed with only a heat source, but it is not preferable from an economic point of view because the moisture content of livestock manure is high, the demand for heat energy input during the drying process is high, and the heat content is not high as a solid fuel. In addition, the problem of the odor of livestock manure generated during drying has been constantly pointed out, and various methods have been attempted to solve this problem.

The problems of the conventional drying process are, firstly, high heat energy consumption, secondly, low calorific value, requiring the input of wood, waste oil, anthracite, oil, etc. Bar, since livestock manure is dried as it is, the amount of odor generated is significant, and a new drying system such as vacuum drying has been invented as a means to solve this problem, but expensive additional facilities (vacuum facilities, odor intake, deodorization and discharge facilities) are essential. there is

Due to the disadvantages of this drying process, the inventors of the present invention developed a process for hydrothermal carbonization of livestock meal. Since the hydrothermal carbonization process of livestock manure is a wet process, it does not require a primary drying process, so the livestock manure can be directly used in the reaction without a pretreatment process, and it is a technology that has a higher calorific value and odor reduction effect than solid fuel produced from the existing drying process. .

However, there is a problem in that high-concentration wastewater is generated in the hydrothermal carbonization process of livestock manure. Until now, a method and device for treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure have not been developed, so there is no background art related thereto. is currently staying in.

On the other hand, high-concentration wastewater treatment technology is mainly applied to anaerobic treatment processes capable of energy recovery and economical treatment.

Here, in the case of a completely agitated anaerobic digestion tank, some of the organic matter introduced into the anaerobic digestion tank is not decomposed and flows out of the digester, so there is a problem in that the concentration of organic matter in the treated water of the digester is high.

In addition, in the case of a medium-temperature digestion tank, the decomposition rate of anaerobic microorganisms is slow compared to a high-temperature digestion tank, so the volume of the anaerobic digestion tank must be increased by 30% or more, so there is a problem in that the initial facility cost is increased.

In addition, in the case of livestock manure hydrothermal carbonization wastewater, the nitrogen concentration is as high as 3,000 to 4,000 mg/l, which can act as a toxic substance to anaerobic microorganisms during anaerobic treatment. There is a problem of requiring a tank, and there is a problem of excessive chemical and power costs for nitrogen removal in the aerobic treatment process.

Patent Document 1: Republic of Korea Patent Registration No. 10-2037447 (sewage sludge vacuum drying fuel system) Patent Document 2: Republic of Korea Patent Registration No. 10-1584621 (Mixing and drying device for converting sewage sludge into fuel and manufacturing method of sewage sludge fuel coal) Patent Document 3: Republic of Korea Patent Application No. 10-2020-0180457 (Method of manufacturing solid fuel with reduced odor using hydrothermal carbonization reaction and solid fuel) Patent Document 4: Korean Patent Application No. 10-2020-0180458 (Method of manufacturing solid fuel with reduced odor using hydrothermal carbonization using acid catalyst and solid fuel) Patent Document 5: Korean Patent Application No. 10-2020-0180459 (Method of manufacturing solid fuel with reduced odor using hybrid hydrothermal carbonization and solid fuel)

Non-Patent Document 1: “Hydrothermal Polymerization Catalytic Process Effect of Various Organic Wastes on Reaction Time, Yield, and Temperature”, Alexis F. Mackintosh, Taesung Shin, Hyunik Yang. Kangil Choe*, Processes 2020, 8(3), 303, 6 March 2020.

The present invention is a method and apparatus for treating high-concentration wastewater generated in the process of manufacturing solid fuel by applying a hydrothermal carbonization process technology of livestock manure, which supplements and improves problems such as odor generated from the drying process of livestock manure, which is a prior art. As for providing, it has the following problems to be solved.

First, it is to solve the problem of completely agitated anaerobic digestion tank, in which some of the organic matter introduced into the anaerobic digestion tank is not decomposed and flows out of the anaerobic digestion tank, and the concentration of organic matter in the anaerobic digestion tank treatment water is high.

Second, compared to the high-temperature anaerobic digestion tank, the anaerobic microbial decomposition rate is slow, so the volume of the anaerobic digestion tank must be increased by 30% or more, so it is to solve the problem of the medium-temperature anaerobic digestion tank, which increases the initial facility cost.

Third, in the case of livestock manure hydrothermal carbonization wastewater, the nitrogen concentration is as high as 3,000 to 4,000 mg/l, which can act as a toxic substance to anaerobic microorganisms during anaerobic digestion. It is to solve the problem of needing an aerobic digestion tank.

Fourth, it is to solve the problem of excessive chemical and power costs for nitrogen removal in the aerobic digestion process.

The present invention, which was made to achieve the above object, relates to a method and apparatus for treating high-concentration wastewater generated in the process of manufacturing solid fuel by applying a hydrothermal carbonization process technology of livestock meal, (1) during hydrothermal carbonization of livestock meal A first anaerobic digestion step of anaerobically digesting the generated high-concentration wastewater by supplying it to a first anaerobic digestion tank through an anaerobic digestion tank raw water inlet pipe; (2) a second anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the first anaerobic digestion step to a second anaerobic digestion tank for anaerobic digestion; (3) a third anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the second anaerobic digestion step to a third anaerobic digestion tank for anaerobic digestion; (4) In the third anaerobic digestion step, high-concentration wastewater generated during hydrothermal carbonization of anaerobically digested livestock is supplied to an anaerobic microbial separation and stabilization tank to separate anaerobic microorganisms and stabilize by accumulating in high concentration at the bottom of the anaerobic microbial separation and stabilization tank Separation and stabilization of anaerobic microorganisms; (5) The anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step are returned to the first anaerobic digestion tank through the anaerobic microorganism internal return pipe, and high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which organic matter is removed is anaerobic treated water ammonia stripping An anaerobic microorganism transport and ammonia stripping reaction step of supplying ammonia to a stripping reactor through an inlet pipe to the reactor and subjecting the ammonia to stripping; And (6) ammonia-removed water return and discharge step of returning high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which ammonia is removed in the anaerobic microorganisms return and ammonia stripping reaction step to the first anaerobic digestion tank through the ammonia-remove water internal return pipe It relates to a method for treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure containing ;

Here, it is preferable to adjust the temperature of high-concentration wastewater generated during hydrothermal carbonization of livestock manure in the first anaerobic digestion step to 50 to 58 ° C and supply it to the first anaerobic digestion tank through the anaerobic digestion tank raw water inlet pipe, wastewater temperature It is more preferable to adjust to 53 to 55 ° C.

In addition, in the first, second, and third anaerobic digestion steps, high-concentration wastewater generated during hydrothermal carbonization of livestock manure is stirred at a speed of 10 to 30 rpm by an agitator, respectively.

And, in the first anaerobic digestion step, the high-concentration wastewater generated during hydrothermal carbonization of the anaerobically digested livestock is supplied from the bottom of the first anaerobic digestion tank to the bottom of the second anaerobic digestion tank, and the anaerobic digestion in the second anaerobic digestion step High-concentration wastewater generated during hydrothermal carbonization of livestock manure is supplied from the upper part of the second anaerobic digestion tank to the upper part of the third anaerobic digestion tank, and the high-concentration wastewater generated during hydrothermal carbonization of the anaerobic digested livestock manure in the third anaerobic digestion step is removed. 3Supply from the bottom of the anaerobic digestion tank to the bottom of the anaerobic microbial separation and stabilization tank, and high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which organic matter generated in the anaerobic microbial separation and stabilization step is removed is ammonia from the top of the anaerobic microbial separation and stabilization tank It is supplied to the top of the stripping reactor.

In addition, in the first anaerobic digestion step, 35 to 40% by weight of organic matter contained in the inflow wastewater is removed by anaerobic digestion of high-concentration wastewater generated during hydrothermal carbonization of livestock manure, and in the second anaerobic digestion step, the inflow Wastewater is anaerobically digested to remove 25 to 30% by weight of organic matter contained in the inflow wastewater, and in the third anaerobic digestion step, 15 to 20% by weight of organic matter contained in the inflow wastewater is anaerobically digested will be removed.

An apparatus for performing the method of treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure described above will be described.

The apparatus of the present invention includes an anaerobic digestion tank raw water inlet pipe for supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure to a first anaerobic digestion tank; A first anaerobic digestion tank, a second anaerobic digestion tank, and a third anaerobic digestion tank for anaerobically digesting the supplied wastewater; an anaerobic microorganism separation and stabilization tank for separating and stabilizing anaerobic microorganisms from the anaerobically digested wastewater supplied from the third anaerobic digestion tank; An anaerobic microorganism internal transport pipe for returning the anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step to the first anaerobic digestion tank; an ammonia stripping reactor inlet pipe for supplying wastewater from which organic matters are removed from the anaerobic microorganism separation and stabilization tank to the ammonia stripping reactor; an ammonia stripping reactor for removing ammonia from organic material-removed wastewater supplied through the ammonia stripping reactor inlet pipe; It is an apparatus for treating high-concentration wastewater generated during hydrothermal carbonization of livestock meal including;

Here, it is characterized in that an agitator is installed inside the first anaerobic digestion tank, the second anaerobic digestion tank, and the third anaerobic digestion tank, and the anaerobic microorganism separation and stabilization tank top is an anaerobic microorganism attachment plastic that anaerobic microorganisms cannot pass through It is characterized in that the media is filled.

The efficient and economical anaerobic digester achieved through the present invention consists of a 4-stage anaerobic digester in which CSTR (completely stirred reactor) and PFR (tubular flow reactor) are mixed, and plastic for attaching anaerobic microorganisms to the middle of the last 4-stage anaerobic digester By filling the media, the outflow of anaerobic microorganisms secured inside the anaerobic digestion tank was minimized.

In addition, high-quality, high-concentration anaerobic microorganisms deposited at the bottom of the 4-stage anaerobic digestion tank are internally returned to the 1st stage of the anaerobic digestion tank to maintain a high concentration of anaerobic microorganisms in the 1st stage anaerobic digestion tank To mitigate the shock load caused by the inflow of high-concentration organic waste into the digester did

Each stage of the anaerobic digestion tank is operated in the CSTR (Completely Stirred Reaction Tank) method, and the organic matter introduced into each stage is decomposed by anaerobic microorganisms secured in each stage. During the first to third stages of anaerobic digestion, more than 80% of the total organic matter removed from the anaerobic digestion tank is removed, and in the last stage 4 filled with plastic media for attaching anaerobic microorganisms, high-quality anaerobic microorganisms deposited on the bottom and the surface of the plastic media 20% of the organic matter remaining by anaerobic microorganisms attached to is decomposed and then discharged to the outside of the anaerobic digestion tank.

In this anaerobic treatment process, the organic matter introduced into the anaerobic digestion tank is completely decomposed, and almost no organic matter is directly discharged to the outside of the anaerobic digestion tank without being decomposed by anaerobic microorganisms.

In general, the internal temperature of the anaerobic digestion tank is operated at 35 ± 1 ℃, which is the appropriate temperature for medium-temperature digestion, but since the temperature of the hydrothermal carbonization wastewater is high at about 55 to 60 ℃, in this patented process, the temperature of the anaerobic digestion tank is 50 It is preferable to shorten the residence time of the anaerobic digestion tank by operating at 58 ° C., and more preferably, operating the temperature of the anaerobic digestion tank at 53 to 55 ° C. shortened by more than 30%.

The total nitrogen concentration of livestock manure hydrothermal carbonization wastewater is high-concentration nitrogen-containing wastewater of 3,000 to 4,000 mg/l. During anaerobic treatment, high-concentration nitrogen acts toxic to anaerobic microorganisms and inhibits the activity of anaerobic microorganisms, and during aerobic treatment of anaerobic treated water, aerobic Since the volume increase of the tank and large-scale denitrification tank are required, more than 90% of the ammonia nitrogen is removed from the anaerobic treated water containing high concentration of ammonia nitrogen using the ammonia stripping process, thereby solving the problems of anaerobic and aerobic treatment of livestock manure hydrothermal carbonization wastewater. Solved.

When removing ammonia nitrogen using ammonia stripping, anaerobic treated water at 50 ° C or higher was used, so it was possible to reduce chemical costs by more than 50% and power costs by more than 70% compared to room temperature of 20 to 25 ° C.

The present invention is a method and apparatus for treating high-concentration wastewater generated in the process of manufacturing solid fuel by applying a hydrothermal carbonization process technology of livestock manure, which supplements and improves problems such as odor generated from the drying process of livestock manure, which is a prior art. As for providing, it has the following effects.

First, some of the organic matter introduced into the anaerobic digestion tank is not decomposed and flows out of the anaerobic digestion tank to show the effect of solving the problem of the completely agitated anaerobic digestion tank having a high concentration of organic matter in the anaerobic digestion tank treatment water.

Second, the decomposition rate of anaerobic microorganisms is slow compared to the high-temperature anaerobic digestion tank, so the volume of the anaerobic digestion tank must be increased by 30% or more, so the initial facility cost is increased.

Third, in the case of livestock manure hydrothermal carbonization wastewater, the nitrogen concentration is as high as 3,000 to 4,000 mg/l, which can act as a toxic substance to anaerobic microorganisms during anaerobic digestion. It shows the effect of solving the problem of needing an aerobic digestion tank.

Fourth, it shows the effect of solving the problem of excessive chemical and power costs for nitrogen removal in the aerobic digestion process.

1 is an apparatus for treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure according to the present invention.

The present invention provides a method and apparatus for treating high-concentration wastewater generated in the process of manufacturing solid fuel by applying a hydrothermal carbonization process technology of livestock manure, which supplements and improves problems such as odor generated from the drying process of livestock manure, which is a prior art. to provide.

In the present invention, carbide generated during hydrothermal carbonization of livestock manure and wastewater containing high-concentration organic matter and ammonia are separated into solid and liquid, the solid carbide is molded and used as fuel, etc., and the separated liquid wastewater containing high-concentration organic matter and ammonia. (Hereinafter referred to as 'high-concentration wastewater generated during hydrothermal carbonization of livestock manure') by using a horizontal high-temperature four-stage anaerobic digestion process and ammonia stripping process, organic matter removal efficiency improved by 10% or more compared to the prior art, and retention in the anaerobic digester by 30% or more When removing ammonia using time reduction and ammonia stripping process, it is possible to save more than 50% of chemical cost by maintaining the inlet temperature at 50℃ or higher, as well as more than 70% of electricity cost, which is an efficient and economical hydrothermal carbonization of livestock manure. It relates to a method and apparatus for treating high-concentration wastewater.

In one embodiment of a method for treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure, (1) supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure to the first anaerobic digestion tank through an anaerobic digestion tank raw water inlet pipe for anaerobic digestion The first anaerobic digestion step; (2) a second anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the first anaerobic digestion step to a second anaerobic digestion tank for anaerobic digestion; (3) a third anaerobic digestion step of supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the second anaerobic digestion step to a third anaerobic digestion tank for anaerobic digestion; (4) In the third anaerobic digestion step, high-concentration wastewater generated during hydrothermal carbonization of anaerobically digested livestock is supplied to an anaerobic microbial separation and stabilization tank to separate anaerobic microorganisms and stabilize by accumulating in high concentration at the bottom of the anaerobic microbial separation and stabilization tank Separation and stabilization of anaerobic microorganisms; (5) The anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step are returned to the first anaerobic digestion tank through the anaerobic microorganism internal return pipe, and high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which organic matter is removed is anaerobic treated water ammonia stripping An anaerobic microorganism transport and ammonia stripping reaction step of supplying ammonia to a stripping reactor through an inlet pipe to the reactor and subjecting the ammonia to stripping; And (6) ammonia-removed water return and discharge step of returning high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which ammonia is removed in the anaerobic microorganisms return and ammonia stripping reaction step to the first anaerobic digestion tank through the ammonia-remove water internal return pipe It is a method of treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure containing ;

And, in one embodiment, the temperature of the high-concentration wastewater generated during hydrothermal carbonization of livestock manure in the first anaerobic digestion step is adjusted to 50 to 58 ° C., and supplied to the first anaerobic digestion tank through the anaerobic digestion tank raw water inlet pipe. It is more preferable to adjust the temperature of the wastewater to 53 to 55 ° C.

In addition, in one embodiment, in the first, second, and third anaerobic digestion steps, high-concentration wastewater generated during hydrothermal carbonization of livestock manure is stirred at a speed of 10 to 30 rpm by an agitator, respectively.

And, in one embodiment, the high-concentration wastewater generated during hydrothermal carbonization of the anaerobically digested livestock in the first anaerobic digestion step is supplied from the lower part of the first anaerobic digestion tank to the lower part of the second anaerobic digestion tank, and the second anaerobic High-concentration wastewater generated during hydrothermal carbonization of anaerobically digested livestock manure in the digestion step is supplied from the upper part of the second anaerobic digestion tank to the upper part of the third anaerobic digestion tank, and generated during hydrothermal carbonization of the anaerobically digested livestock manure in the third anaerobic digestion step The high-concentration wastewater is supplied from the bottom of the third anaerobic digestion tank to the bottom of the anaerobic microbial separation and stabilization tank, and the organic matter generated in the anaerobic microbial separation and stabilization step is removed during hydrothermal carbonization of livestock manure. It is supplied from the top of the stabilization tank to the top of the ammonia stripping reactor.

In addition, in one embodiment, in the first anaerobic digestion step, 35 to 40% by weight of organic matter contained in the inflow wastewater is removed by anaerobic digestion of high-concentration wastewater generated during hydrothermal carbonization of livestock manure, and the second anaerobic In the digestion step, the inflow wastewater is anaerobically digested, and 25 to 30% by weight of the organic matter contained in the inflow wastewater is removed. 15 to 20% by weight is removed.

An embodiment of an apparatus for performing the method of treating high-concentration wastewater generated during hydrothermal carbonization of livestock manure described above will be described.

An apparatus according to an embodiment of the present invention includes an anaerobic digestion tank raw water inlet pipe for supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure to a first anaerobic digestion tank; A first anaerobic digestion tank, a second anaerobic digestion tank, and a third anaerobic digestion tank for anaerobically digesting the supplied wastewater; an anaerobic microorganism separation and stabilization tank for separating and stabilizing anaerobic microorganisms from the anaerobically digested wastewater supplied from the third anaerobic digestion tank; An anaerobic microorganism internal transport pipe for returning the anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step to the first anaerobic digestion tank; an ammonia stripping reactor inlet pipe for supplying wastewater from which organic matters are removed from the anaerobic microorganism separation and stabilization tank to the ammonia stripping reactor; an ammonia stripping reactor for removing ammonia from organic material-removed wastewater supplied through the ammonia stripping reactor inlet pipe; It is an apparatus for treating high-concentration wastewater generated during hydrothermal carbonization of livestock meal including;

And, in one embodiment, it is characterized in that the stirrer is installed inside the first anaerobic digestion tank, the second anaerobic digestion tank, and the third anaerobic digestion tank, and the anaerobic microorganisms can pass through the upper part of the anaerobic microbial separation and stabilization tank It is characterized by being filled with plastic media for attaching anaerobic microorganisms without.

A comprehensive description of the method and apparatus of the above-described embodiment is as follows. That is, the process of removing organic matter and ammonia from high-concentration wastewater generated during hydrothermal carbonization of livestock manure consists of a horizontal high-temperature anaerobic digestion process and ammonia stripping process to remove organic matter, and organic matter removal in an anaerobic digestion tank and ammonia in the ammonia stripping process Elimination proceeds sequentially.

Carbonates generated during hydrothermal carbonization of livestock manure are separated in a solid-liquid separator and used as fuel after being molded and dried. A high temperature of 60 ° C or higher is preferably adjusted to 50 to 58 ° C using a heat exchanger, and then supplied to the first anaerobic digestion tank (1) through the anaerobic digestion tank inlet pipe (8), more preferably 53 to 55 ° C. It is supplied after adjustment.

In the first anaerobic digestion tank (1), an anaerobic digestion tank agitator (5) capable of adjusting the stirring speed is installed, and the stirring speed is adjusted to 10 to 30 rpm to increase the inflow of organic matter and anaerobic microorganisms in the first anaerobic digestion tank (1). It was possible to ensure smooth contact and a large amount of anaerobic microorganisms in the lower part of the first anaerobic digestion tank (1).

When wastewater containing high concentrations of organic matter flows into the first anaerobic digestion tank (1), it can act as a temporary shock load to anaerobic microorganisms, so high-quality activation secured at the bottom of the anaerobic microorganism separation and stabilization tank (4), which is the last section of the anaerobic digestion tank 30 to 50% of the inflow rate of the anaerobic microorganisms into the first anaerobic digestion tank (1) is internally returned to the first anaerobic digestion tank (1) through the anaerobic digestion tank raw water inlet pipe (8) to mitigate the shock load and remove organic matter in the first anaerobic digestion tank (1) improvement was possible.

The inflow wastewater from which 35 to 40% of organic matter is removed from the first anaerobic digestion tank (1) is transferred to the upper part of the second anaerobic digestion tank (2) through the lower part of the first anaerobic digestion tank (1). In the second anaerobic digestion tank (2), as in the first anaerobic digestion tank (1), an agitator capable of adjusting the stirring speed is installed, and by adjusting the stirring speed to 10 to 30 rpm, the first in the second anaerobic digestion tank (2) It was possible to secure a large amount of anaerobic microorganisms at the bottom of the second anaerobic digestion tank (1) and smoothly contact the organic matter remaining after decomposition in the anaerobic digestion tank (1) with anaerobic microorganisms. In the second anaerobic digestion tank (2), about 25 to 30% of the inflow organic matter is removed, and the wastewater from which the organic matter is removed is transferred to the third anaerobic digestion tank through the upper part of the second anaerobic digestion tank (2).

Like the first anaerobic digestion tank (1) and the second anaerobic digestion tank (2), an agitator capable of adjusting the stirring speed is installed in the third anaerobic digestion tank (3), and after organic matter is removed in the second anaerobic digestion tank (2) The remaining organic matter passes through the anaerobic microorganisms at the top of the third anaerobic digestion tank (3) and the high-concentration anaerobic microorganism layer at the bottom (7), after which 15 to 20% of the inflow organic matter is removed. Separation and stabilization of anaerobic microorganisms, the final group of the anaerobic digestion tank It is transferred to Joe (4).

The upper part of the anaerobic microorganism separation and stabilization tank (4) is filled with plastic media (6) for attaching anaerobic microorganisms, and the anaerobic microorganisms transferred from the third anaerobic digestion tank (3) to the lower part of the anaerobic microorganism separation and stabilization tank (4) are moved to the upper part. In the process of being transported, it does not pass through the plastic media layer and accumulates in high concentration at the bottom of the anaerobic microbial separation and stabilization tank (4).

High-concentration anaerobic microorganisms of good quality accumulated in the lower part flow into the first anaerobic digestion tank (1), and about 30 to 50% of the wastewater is continuously returned to the inside, reducing the impact load of anaerobic microorganisms in the first anaerobic digestion tank (1) and anaerobic microorganisms It was made to contribute to the improvement of organic matter removal efficiency through the increase in concentration.

In the process of the present invention, the anaerobic digestion tank is composed of a high-temperature four-stage anaerobic digestion tank combining a CSTR (completely stirred reaction tank) method and a PFR (tubular flow reaction tank) method so that organic matter in the inflow wastewater is not decomposed and discharged outside the anaerobic digestion tank Compared to medium-temperature digestion, which maintains the internal temperature of the anaerobic digestion tank at 35 ± 1 ° C, the retention time is reduced by 30% or more, while organic matter removal efficiency of 90% or more is possible.

The livestock manure hydrothermal carbonization wastewater after anaerobic treatment has a suspended solids concentration of 1,000 mg/l or less, and the temperature is maintained at about 50 ° C. ) is supplied.

The concentration of ammonia nitrogen in the wastewater from hydrothermal carbonization, which can be removed in the ammonia stripping process after hydrothermal carbonization, is about 20 to 30% of the total nitrogen concentration, but organic nitrogen is decomposed by anaerobic microorganisms during the anaerobic treatment process, resulting in The normal nitrogen concentration is about 90 to 95% of the total nitrogen concentration.

Inside the ammonia stripping reactor 12, a plastic media of about 40 to 50% of the volume of the ammonia stripping reactor 12 is used to facilitate contact between ammonia nitrogen flowing into the upper part of the ammonia stripping reactor 12 and air flowing into the lower part is filled

In general, when ammonia is removed using the ammonia stripping process, the pH of the inflow wastewater must be maintained at about 9 to 10 to efficiently remove ammonia at room temperature of about 25 to 30 ° C. Amount of air supplied to the lower part of the ammonia stripping reactor 12 It is necessary to supply about 1,500 to 2,000 times the inflow wastewater in volume ratio, but when the temperature of the inflow wastewater is about 50 ° C, the pH of the inflow wastewater flowing into the ammonia stripping reactor 12 is maintained at about 8 to 9, and the ammonia stripping reactor (12 ) Even if the amount of air supplied to the lower part is 300 to 500 times the amount of inflow wastewater in terms of volume, it is possible to remove ammonia with high efficiency of 90% or more. As described above, 70 to 80% of the ammonia-removed water from which 90% or more of ammonia is removed is transferred to the first anaerobic digestion tank (1), and ammonia of the wastewater containing high concentration of ammonia flowing into the first anaerobic digestion tank (1) By lowering the concentration, the toxicity of anaerobic microorganisms due to high concentration of ammonia was alleviated, thereby contributing to the activation of anaerobic microorganisms and the improvement of organic matter removal efficiency by anaerobic microorganisms.

1: 1st anaerobic digestion tank
2: 2nd anaerobic digestion tank
3: 3rd anaerobic digestion tank
4: Anaerobic microorganism separation and stabilization tank
5: anaerobic digestion tank agitator
6: Plastic media attached to anaerobic microorganisms
7: high-concentration anaerobic microbial layer at the bottom of the anaerobic digester
8: Anaerobic digestion tank raw water inlet pipe
9: Anaerobic microorganism internal return pipe
10: Excess anaerobic microorganism discharge pipe
11: anaerobic treatment water ammonia stripping reactor inlet pipe
12: ammonia stripping reactor
13: plastic media for dispersing anaerobic treatment water
14: ammonia stripping reactor air supply pipe
15: ammonia removal water internal return pipe

Claims (2)

(1) A first anaerobic digestion step of controlling the temperature of high-concentration wastewater generated during hydrothermal carbonization of livestock meal to 53 to 55 ° C and supplying it to the upper part of the first anaerobic digestion tank through the raw water inlet pipe of the anaerobic digestion tank for anaerobic digestion;
(2) a second anaerobic digestion step of anaerobically digesting high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the first anaerobic digestion step by supplying it from the bottom of the first anaerobic digestion tank to the bottom of the second anaerobic digestion tank;
(3) a third anaerobic digestion step of anaerobically digesting high-concentration wastewater generated during hydrothermal carbonization of livestock manure anaerobically digested in the second anaerobic digestion step by supplying it from the top of the second anaerobic digestion tank to the top of the third anaerobic digestion tank;
(4) In the third anaerobic digestion step, high-concentration wastewater generated during hydrothermal carbonization of anaerobically digested livestock is supplied from the lower part of the third anaerobic digestion tank to the lower part of the anaerobic microorganism separation and stabilization tank, and the anaerobic microorganisms filled in the middle of the tank An anaerobic microorganism separation and stabilization step of separating and stabilizing anaerobic microorganisms by accumulating and stabilizing the anaerobic microorganisms at a high concentration in the lower part of the anaerobic microorganism separation and stabilization tank by the plastic media attached to the anaerobic microorganisms that cannot pass through;
(5) The anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step are returned to the first anaerobic digestion tank through the anaerobic microorganism internal return pipe, and high-concentration wastewater generated during hydrothermal carbonization of livestock manure from which organic matter is removed is anaerobic microorganism separation and stabilization An anaerobic microorganism return and ammonia stripping reaction step of supplying anaerobic treated water from the top of the tank to the top of the ammonia stripping reaction tank through an inlet pipe to the ammonia stripping reaction tank for ammonia stripping treatment; and
(6) High concentration wastewater generated during hydrothermal carbonization of livestock manure from which ammonia is removed in the anaerobic microorganism return and ammonia stripping reaction steps is returned to the top of the first anaerobic digestion tank through the ammonia removal water internal return pipe Return and discharge of ammonia removal water Step; as configured to include,
In the first, second, and third anaerobic digestion steps, high-concentration wastewater generated during hydrothermal carbonization of livestock manure is stirred by a stirrer at a speed of 10 to 30 rpm, respectively.
In the first anaerobic digestion step, 35 to 40% by weight of organic matter contained in the inflow wastewater is removed by anaerobic digestion of high-concentration wastewater generated during hydrothermal carbonization of livestock manure,
In the second anaerobic digestion step, the inflow wastewater is anaerobically digested, and 25 to 30% by weight of organic matter contained in the inflow wastewater is removed.
In the third anaerobic digestion step, the inflow wastewater is anaerobically digested and 15 to 20% by weight of organic matter contained in the inflow wastewater is removed.
An apparatus for performing the method of claim 1,
An anaerobic digestion tank raw water inlet pipe for supplying high-concentration wastewater generated during hydrothermal carbonization of livestock manure to the first anaerobic digestion tank;
A first anaerobic digestion tank, a second anaerobic digestion tank, and a third anaerobic digestion tank each having an agitator installed therein as an anaerobic digestion tank for anaerobically digesting the supplied wastewater;
Anaerobic microorganism separation and stabilization tank for separating and stabilizing anaerobic microorganisms from the anaerobic digested wastewater supplied from the third anaerobic digestion tank. stabilization bath;
An anaerobic microorganism internal transport pipe for returning the anaerobic microorganisms separated in the anaerobic microorganism separation and stabilization step to the first anaerobic digestion tank;
an ammonia stripping reactor inlet pipe for supplying wastewater from which organic matters are removed from the anaerobic microorganism separation and stabilization tank to the ammonia stripping reactor;
an ammonia stripping reactor for removing ammonia from organic material-removed wastewater supplied through the ammonia stripping reactor inlet pipe; and
An apparatus for treating high-concentration wastewater generated during hydrothermal carbonization of livestock meal comprising: an ammonia-removed water internal conveying pipe for returning the ammonia-removed wastewater from the ammonia stripping reactor to the first anaerobic digestion tank.

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