JP2003305491A - Method for boiling treatment of sewage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewage treating method by which organic sludge is thermally dissolved before sewage treating process by microorganisms to facilitate decomposition by the microorganisms and by which the organic sludge can be efficiently dissolved with easy temperature control, in particular. <P>SOLUTION: In microbiological treatment of the sewage, when raw sewage has low fluidity, water is added to the sewage in the boiling tank or in the course of being introduced into a boiling tank to dilute BOD concentration below 10,000 ppm and to increase fluidity. Further the sewage is heated and is temperature-controlled at between 55°C and 98°C and sewage of high temperature in the boiling tank is introduced in a mixing pipe, is mixed therein and then is returned in the boiling tank again and mixing circulation is continued. When the sludge becomes in a soluble state in the boiling tank, the boiled sewage is transferred to a decomposing treatment process by microorganism. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for efficiently purifying organic wastewater such as domestic wastewater and livestock wastewater discharged in large quantities.

[0002]

2. Description of the Related Art In order to purify organic wastewater such as domestic wastewater, livestock wastewater, and industrial wastewater of hotels and restaurants, various wastewater purification methods using microorganisms have been proposed and implemented so far.

In general, an activated sludge method has been widely practiced, in which the wastewater in the wastewater treatment tank is aerated and the organic sludge is decomposed by aerobic microorganisms. And usually in the case of this method, the optimum temperature for aerobic microorganisms,
That is, it is said that a temperature condition slightly higher than room temperature is preferable.

In general, even if aerobic microbial treatment by aeration is performed, when the temperature of sewage is low, the dissolution rate of dissolved oxygen dissolved in water is increased and the supply of oxygen is increased. Activity becomes inactive and processing capacity does not increase. On the contrary, in the case of high temperature, when the temperature is low, the activity of microorganisms is activated, but the dissolution rate of dissolved oxygen dissolved in water is lowered and the supply of oxygen is reduced. The processing capacity could not be increased. That is, there is a problem that the processing capacity is lowered regardless of whether the temperature is low or high. In addition, there is a problem that a strong odor is emitted when the temperature is high.

Therefore, as a method of reducing the burden of the processing amount in such a processing tank, a solid material such as raw garbage is separated and removed in a garbage basket and a grease trap is installed before flowing into the processing tank. Then, the oil and fat component is preliminarily separated and removed. There is also a reduction method by using a coagulant or the like, but a coagulant such as a cation that is usually used is not preferable for the environment, and therefore there is a problem that the coagulant must be subjected to a secondary treatment.

[0006] Further, in a wastewater treatment method having a low treatment capacity,
For the treatment of a large amount of wastewater, it is generally adopted that the treatment volume can be dealt with by enlarging the scale of the treatment tank. However, in urban areas, it is very difficult to secure a large facility site nearby that can be sufficiently treated.

[0007] Therefore, even if only aeration is performed, there is a limit. Therefore, in order to further enhance the treatment capacity, many microorganisms become habitat for the microorganisms to promote the reproduction of the microorganisms and enhance the sludge decomposing ability. As described above, sewage treatment tanks in which a microbial carrier made of a material having a large contact surface area with sewage is added are implemented. In a sewage treatment tank using such a carrier, when sewage containing a large amount of fats and oils or sewage with a high concentration SS value flows in, an oil film that cannot be decomposed by ordinary microorganisms or a sewage substance that cannot be decomposed sticks to the surface of the microbial carrier, Then, in any carrier, there is a problem that the voids and meshes of the carrier are always clogged, the original function of the carrier is deteriorated, and in the worst case, the processing function cannot be obtained.

Further, in the treatment method using anaerobic microorganisms, the sewage treatment tank is sealed and various degrading synthetic bacteria decompose organic sludge in the anaerobic treatment tank into methane, hydrogen sulfide gas and the like. However, there is a case where the temperature becomes high due to heat generation, and there is a case in which this temperature is forcibly set to a high temperature environment suitable for anaerobic bacteria to promote decomposition. However, in this method, the solubilization of the organic sludge cannot be efficiently obtained, and in adjusting the temperature, it is necessary to adjust the temperature to about 50 to 70 ° C., which is usually preferred by anaerobic microorganisms. If the temperature was further raised, the various degrading bacteria would weaken and eventually die, so there was a limit to the degree of high temperature.

Therefore, technical proposals have been made to more efficiently treat the above problems in microbial treatment from another viewpoint. It is called the hydrothermal / biological method, and it is intended to dissolve sludge by a hydrothermal reaction device at a high temperature of 150 to 300 ° C. to facilitate the subsequent decomposition by microorganisms. In the case of this method, since the hydrothermal reaction is performed, the treatment time efficiency can be improved by boiling the sewage for a short time to dissolve the organic matter, but its temperature control is difficult because of extremely high temperature, Since it is generated, there is a drawback that a large amount of energy is consumed by the heat of vaporization. Further, when pressure is applied in order to suppress the heat of vaporization, the high-temperature pressurizing device becomes complicated, and the device therefor must be large-scaled.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and the organic wastewater is dissolved by a hydrothermal reaction before entering the wastewater treatment step by the microorganisms, whereby the subsequent decomposition by the microorganisms. Sewage that exceeds the treatment capacity of various sewage purification systems equipped with microbial wastewater treatment tanks for treating organic wastewater such as domestic wastewater, livestock wastewater, and industrial wastewater of hotels and restaurants. Even if it occurs, it can be sufficiently dealt with by pre-treating it, and in particular, it can be made extremely compact in terms of equipment, and temperature can be easily controlled without boiling or pressurizing, It is intended to provide a sewage treatment method capable of efficiently dissolving organic sludge by mixing.

[0011]

In order to solve the above problems, the sewage sewage treatment method in the wastewater microbiological treatment method of the present invention is mainly a method of stirring and circulating sewage in a simmer tank and sewage sewage. There are two types of stirring methods before placing in the tank.

First, the former type of configuration will be described.

In the case of low fluidity of the raw sewage, this type of form adds water to the raw sewage while introducing it into the boiling tank or in the boiling tank to obtain a BOD concentration of about 10,000 p.
While diluting to pm or less to improve fluidity and heating the sewage to adjust the temperature to 55 ° C to 98 ° C, the sewage in the simmering tank is extracted and stirred, and then returned to the simmering tank again. Continue circulation. Then, after the sludge is in a solubilized state in the stewing tank, the stewed wastewater is transferred to a decomposition treatment step by microorganisms.

Separately from this, when the fluidity of the raw sewage is low, water is added to the raw sewage during the introduction into the boiling tank or in the boiling tank so that the BOD concentration is about 10,000 p.
While diluting to pm or less to improve fluidity and heating the sewage to adjust the temperature to 55 ° C to 98 ° C, the sewage in the simmering tank is extracted and stirred, and then returned to the simmering tank again. Continue circulation. Then, after the sludge becomes in a solubilized state in the stewing tank, the stewed sewage is passed through a mixing pipe together with the injected air to be mixed in the mixing pipe, and then transferred to a microbial decomposition treatment step. It is characterized by

Further, in the above-mentioned structure, the method of stirring the sewage used for the agitation circulation is such that the sewage in the simmering tank is drawn out, pressure-fed, and passed through the mixing pipe to be mixed in the mixing pipe before simmering. It is agitated and circulated to be returned to the tank.

Further, in the above-mentioned structure, the method of stirring the waste water used for the stirring circulation is such that the high temperature waste water in the boiling tank is drawn out and pressure-fed, and is passed through the mixing pipe together with the injected air, thereby mixing in the mixing pipe. After that, it is stirred and circulated to be returned to the boiling tank.

Further, in the above-mentioned structure, the method of stirring the sewage used for the stirring circulation is such that the sewage in the boiling tank is drawn out and introduced into the stirring circulation tank, and the stirring circulation tank is stirred at a high speed, and then in the boiling tank. It is agitated and circulated to return to.

Further, in the above structure, the method of stirring the waste water used for the stirring circulation is to draw the waste water out of the boiling tank and introduce it into the stirring circulation tank. Then, while stirring at high speed in the stirring / circulating tank, the waste water in the stirring / circulating tank is extracted, pressure-fed, and passed through the mixing pipe to be mixed in the mixing pipe and then returned to the stirring / circulating tank. Circulate with stirring. Then, the agitated circulation in which the agitated wastewater in the agitation circulation tank is returned to the boiling tank is performed.

Further, in the above construction, when high speed stirring is carried out in the stirring circulation tank, the wastewater in the stirring circulation tank is kept at 55 ° C.
It is characterized in that the temperature is adjusted to 98 ° C.

Next, the latter type of configuration will be described.

In the case of low flowability of the raw sewage, this type of form adds water to the raw sewage in the stirring tank to dilute the BOD concentration to about 10000 ppm or less before introducing the sewage into the boiling tank to improve the fluidity. As it is raised, the waste water is stirred in the stirring tank. The agitated sewage is introduced into a simmering tank, and the sewage is heated to a temperature of 55 ° C to 98 ° C. Then, after the sludge is solubilized in the stewing tank, the stewed wastewater is transferred to a decomposition treatment step by microorganisms.

On the other hand, when the fluidity of the raw sewage is low, water is added to the sewage in the agitation tank to dilute the BOD concentration to about 10000 ppm or less before introducing the sewage into the simmering tank to improve the fluidity. As it is raised, the waste water is stirred in the stirring tank. The agitated sewage is introduced into a simmering tank, and the sewage is heated to a temperature of 55 ° C to 98 ° C. Then, after the sludge becomes in a solubilized state in the simmering tank, the sewage sewage is allowed to pass through a mixing pipe together with the injected air so that the mixture is mixed in the mixing pipe and then transferred to a microbial decomposition treatment step. It is characterized by.

In the above construction, the method of stirring the sewage in the agitation tank is such that the sewage in the agitation tank is extracted, pressure-fed, and passed through the mixing pipe to mix it in the mixing pipe. It is agitated and circulated to be returned to the agitating tank.

Further, in the above construction, the method of stirring the sewage in the agitation tank is such that the sewage in the agitation tank is drawn out, pressure-fed, and passed through the mixing pipe together with the injected air so that After mixing, the mixture is circulated by stirring and returned to the stirring tank.

Further, in the above construction, the method of stirring the sewage in the stirring tank is characterized in that the sewage in the stirring tank is stirred at a high speed.

Further, in the above construction, the method of stirring the dirty water in the stirring tank is the method of stirring the dirty water in the stirring tank, and the dirty water in the stirring tank is drawn out and pressure-fed to be passed through the mixing pipe. This is characterized by a combination of stirring circulation in which mixing is performed in the mixing pipe and then returned to the stirring tank, and sewage in the stirring tank is stirred at high speed.

Further, in the above-mentioned constitution, when stirring in the stirring tank, the temperature of the waste water in the stirring tank is adjusted to 55 to 98 ° C.

In the above construction, the method of stirring the sewage in the stirring tank is such that the sewage in the stirring tank is stirred at a low speed for several minutes while controlling the temperature to 55 ° C to 98 ° C, and then the stirring tank is stirred. It is characterized in that agitation circulation is carried out in which the sewage therein is extracted, pressure-fed, and passed through a mixing pipe to be mixed in the mixing pipe and then returned to the stirring tank.

Further, in each of the configurations of the above embodiments, sodium hydroxide, a surfactant or an enzyme agent is added to the sewage during or before stirring.

Further, in each of the above-mentioned configurations, the microbial hardly-decomposable solid matter contained in the wastewater is removed before the wastewater is passed through the first mixing pipe.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The sewage sewage treatment method in the sewage microbial treatment method of the present invention is mainly a method of stirring and circulating the sewage in a stew tank (shown in the flow chart of FIG. 1).
There are two types of methods (shown in the flow chart of FIG. 2) in which sewage is stirred before being put into the boiling tank. These embodiments will be described below based on the examples in the drawings.

First, the method of stirring and circulating the dirty water in the boiling tank shown in the flow chart of FIG. 1 will be described in detail with reference to FIGS. 3 to 8 showing the apparatus for carrying out the method.

In this embodiment, the raw sewage G has a high fluidity and a low fluidity. When the fluidity is high (BO
When the D concentration is about 10,000 ppm or less), it is not necessary to dilute.

The reason is that the BOD concentration of sewage is about 130.
When it becomes about 00 ppm, it becomes difficult to pass through the mixing pipe 1, and the passing efficiency falls. Furthermore, 15000pp
This is because, if it is m or more, the agitator 22 may be difficult to operate or may not flow into the mixing pipe 1 depending on the pipe diameter.

Therefore, when the fluidity is low, as shown in FIG. 3, the raw sewage G is introduced into the microbial hardly decomposable solids removing device 7 through the water pipe 9, and the solids removing device 7 is made of ceramics. And stainless steel stew tank 2
It is introduced to the via a water pipe 8. Then, in the simmering tank 2, water W is added to the sewage G to dilute the BOD concentration to about 10,000 ppm or less to enhance the fluidity.

The above-mentioned apparatus 7 for removing microbial hardly decomposable solid matter is
Hair, vinyl strings, synthetic resin wrap pieces, plastic pieces, metal pieces, pottery pieces, etc. in dirty water are flushed with water for selective removal. As the solid substance removing device 7, a device such as a wire net, a non-woven cloth screen having a rough bud, or a drum screen can be used.

Then, the wastewater D is heated in the boiling tank 2 to adjust the temperature to 55 ° C to 98 ° C. At the same time, the temperature-controlled high-temperature sewage D is converted into the high-temperature sewage D in the boiling tank 2.
The water is introduced into the mixing pipe 1 provided with the tongue pieces by the pump 4 via the water supply pipe 5 and the tongue pieces are alternately provided, and mixing is performed, and the stirring circulation in which the mixture is returned to the boiling tank 2 by the return pipe 6 is continued. Since hair and vinyl strings have been previously removed from the mixing pipe 1 by the microorganism-hardly decomposing solids removing device 7, obstacles such as hair clogging can be prevented.

After about 30 minutes to 1 hour, when the sludge becomes solubilized in the simmering tank 2, the sewage sewage D is transferred to a microbial decomposition treatment step.

The simmering tank 2 is provided with an electric heater 3 for adjusting the temperature, and the electric heater 3 is connected to a power source through a control unit equipped with a temperature sensor installed in the simmering tank. Then, the sewage water D that has been boiled is sent to the sewage treatment tank 10 for microorganisms by the pump 12 via the water supply pipe 11.

The sewage treatment tank 10 is a sewage treatment tank 10 for carrying out a conventional treatment method using microorganisms,
It can be used for most sewage treatment tanks 10 including an aerobic treatment tank, an anaerobic treatment tank, and a composite sewage treatment system S including both of them.

Further, since the apparatus shown in FIG. 4 does not rely on the mixing pipe 1 in which hair clogging occurs, the apparatus 7 for removing microbial hardly decomposable solid matter is omitted. In this case, the raw sewage G is introduced directly into the simmering tank 2 through the water pipe 9, and the water W is directly added to the simmering tank 2 to dilute the BOD concentration to about 10,000 ppm or less to improve the fluidity. .

As described above, in the method which does not rely on the mixing pipe 1, the temperature-controlled high-temperature sewage D is boiled in the boiling tank 2 thereof.
The high temperature sewage D therein is introduced into the stirring circulation tank 21 by the pump 4 via the water supply pipe 5, and is stirred by the stirrer 22 with blades by the stirring motor 23, and the stirring circulation tank 21 is stirred.
The agitation circulation in which the sewage of (1) is put back into the boiling tank 2 by the return pipe 6 is continued. After about 30 minutes to 1 hour, when the sludge becomes solubilized in the simmering tank 2, the sewage sewage D is transferred to a decomposition treatment step by microorganisms.

Further, as shown in FIGS. 3 to 5, the sewage water D that has been boiled is then sent directly to the sewage treatment tank 10 by microorganisms by the pump 12 via the water supply pipe 11 as in the above method. As shown in FIGS. 6 to 8, the sewage D is fed into the boiling water tank 2 through the high temperature sewage D in the water pipe 1
There is a method in which the pump 12 is introduced into the mixing pipe 1 having irregularities or alternating tongues in the pipe through the pump 1 together with the air injected from the air injection pipe 20 to perform mixing. In this latter method, fine bubbles can be introduced into the sewage of the next sewage treatment tank 10, whereby oxygen in the bubbles is supplied to the aerobic microorganisms in the sewage treatment tank 10 for sludge decomposition treatment. Can be promoted.

Further, as for the method of stirring the dirty water in the stirring circulation tank 21, as shown in FIG. 8, the mixing by the mixing pipe 1 and the stirring by the stirrer 22 can be performed simultaneously.

Next, a method of stirring the waste water shown in the flow chart of FIG. 2 before putting it into the boiling tank will be described in detail with reference to FIGS. 9 to 13 showing an apparatus for carrying out the method.

Also in this embodiment, similarly to the above method,
The raw sewage G has a high fluidity and a low fluidity. When the fluidity is high (when the BOD concentration is about 10,000 ppm or less), it is not necessary to dilute.

However, this method is different from the above-mentioned method.
The raw sewage G is first introduced into the stirring tank 13, and when the raw sewage G has low fluidity, water W is added to the stirring tank 13 again to dilute the BOD concentration to about 10,000 ppm or less to improve the fluidity. A big difference is that the sewage having high fluidity is stirred, and then the sewage having high fluidity is stirred and then fed into the boiling tank 2.

This method also has various forms similar to the above-mentioned form, and as shown in FIG. 9, the waste water D in the stirring tank 13 is introduced into the mixing pipe 1 by the pump 15 via the water supply pipe 14, It is advisable to continue the mixing circulation of returning the water from the water discharge pipe 16 back into the stirring tank 13 for at least several minutes. At this time, as shown in FIG. 10, when the heater 19 provided in the stirring tank 13 is stirred at a temperature of 55 ° C. to 98 ° C., the organic matter melted by the water heat can be mechanically destroyed by mixing, so that the solubilization is performed. A dramatic synergistic effect appears.

Then, the mixing treated sewage D
The water is supplied from the stirring tank 13 via the water supply pipe 17 by the pump 18 and introduced into the boiling tank 2. Then, the sewage D is heated in the simmering tank 2 by the heater 3 and its temperature is adjusted to 55 ° C. to 98 ° C., and when the sludge becomes solubilized in the simmering tank 2, the sewage D is treated in the same manner as in the above method. Water is sent by a pump 12 through a water pipe 11 to a sewage treatment tank 10 in which a conventional treatment method using microorganisms is carried out.

Further, as shown in FIG.
The sewage D in the inside is continuously stirred by a stirrer 22 with a blade by a stirring motor 23, and the stirred tank 13 is stirred.
The sewage is guided by the pump 18 through the water supply pipe 17 and sent into the simmering tank 2. In addition, the agitator 23 is guided by the pump 15 through the water supply pipe 14 and again from the water discharge pipe 16 to the agitator tank 1.
Continue mixing circulation for returning to 3 within a while. Also at this time, if a heater (not shown) provided in the stirring tank 13 is stirred at a temperature of 55 ° C. to 98 ° C., the organic matter melted by hydrothermal heat can be mechanically destroyed by mixing, which is a leap in solubilization. The synergistic effect appears.

As for the method of stirring the dirty water in the stirring tank 13, as shown in FIG. 11, the mixing by the mixing pipe 1 and the stirring by the stirrer 24 can be performed simultaneously. Also in this case, the stirring tank 13
When the heater 19 provided inside is stirred at a temperature of 55 ° C to 98 ° C while stirring, hydrothermally dissolved organic matter can be mechanically destroyed by mixing, so that a dramatic synergistic effect appears for solubilization.

Regarding the method of stirring the sewage in the stirring tank 13, the sewage D that has been boiled is then directly pumped into the sewage treatment tank 10 by microorganisms via the water supply pipe 11 as in the above method. 12, and as shown in FIG. 12, the sewage D is mixed with the high temperature sewage D in the simmering tank 2 via the water supply pipe 11, and a pump 12 is provided with irregularities or alternating tongue pieces in the pipe. There is a method in which the air is introduced from the air injecting tube 20 together with the air injected into the air injection tube 1 and mixed and sent. In this latter method, fine bubbles can be introduced into the sewage of the next sewage treatment tank 10 as in the above method. Then, oxygen in the bubbles can be supplied to the aerobic microorganisms in the wastewater treatment tank 10 to accelerate the sludge decomposition treatment.

Further, as shown in FIG. 13, the mixing circulation in which the wastewater D in the stirring tank 13 is guided to the mixing pipe 1 by the pump 15 via the water supply pipe 14 and returned to the stirring tank 13 from the water discharge pipe 16 again. When air is injected from the air injection pipe 20 while continuing for a while, the sludge component dissolving effect is enhanced by the fine bubbles generated thereby.

As a method of increasing the dissolution efficiency, it is effective to add sodium hydroxide, a surfactant or an enzyme agent to the wastewater during or before the mixing in each of the above-mentioned constitutions. For example, if 40 kg of sodium hydroxide is added to 10 tons of treated sewage, it will be 10
It has been confirmed by experiments that the efficiency is improved by as much as%.

When the mixing pipe 1 is used in a stirring process for stirring sewage or when water is sent to the sewage treatment tank 10, the mixing pipe 1 is used in any case.
In order to prevent the occurrence of troubles such as hair clogging inside, removing the hair and the vinyl string in advance by the microbial hardly decomposing solids removing device 7 puts the hair and vinyl string on the hair removing work and the like, and smooth management is achieved. Will be able to.

[0056]

The organic sludge is boiled at a high temperature of 55 ° C. to 98 ° C. at which water does not evaporate without being pressure-boiled at an extremely high temperature, and at the same time, the organic sludge is passed through the mixing pipe 1 and mixed to be contained in the waste water. The cell walls derived from living organisms are lysed by heat and the weakened cell walls are mechanically destroyed by mixing, whereby the cell fluid is effectively dissolved in water. That is, the dissolution efficiency of organic substances was synergistically increased by hydrothermal dissolution and mixing breakdown. Further, by adding a chemical having a property of dissolving an organic substance, that is, sodium hydroxide, a surfactant or an enzyme, to the waste water during or before stirring, the dissolution efficiency can be further enhanced.

When the air is injected through the mixing pipe 1 to mix the air, the concentration of dissolved oxygen in the wastewater D is significantly increased. This is very preferable for the aerobic microorganisms in the sewage treatment tank 10 by the microorganisms to be used later, and the oxygen is consumed to extremely actively decompose the organic substances. Therefore, the load on the sewage treatment capacity of the sewage treatment tank 10 is significantly reduced.
Further, there is an advantage that the bad odor can be prevented by the bubbles generated by this mixing, and the stirring state can be confirmed by checking the state of the bubbles contained in the sampling test of the dirty water.

[0058]

[Test Example 1] Conventionally, the solubilization rate was about 90% after being treated for about 6 hours or more, but it can be increased to about 90% or more by treatment for about 30 minutes to 1 hour. It was The following is the time required for the temperature when the solubilization rate is 90%. 20 ° C: PH11 (adjusted with caustic soda) 6 to 12 hours (beaker test) 50 ° C: PH2.5 (adjusted with sulfuric acid) about 2 hours 85 ° C: PH7 about 10 minutes (with stirring) 85 ° C: PH11 (adjusted with caustic soda) ) About 10 minutes (with stirring)

The "solubilization" referred to in the present invention is to destroy the cell wall of an organism so that the cell fluid in the cell is dissolved in water. The "solubilization rate" is a numerical value obtained by dividing the stock solution COD concentration by the COD concentration "solved-COD concentration (S-COD)" of the cell solution that has passed through the filter. To make the solubilization rate 90%, it is about 6-12 at 20 ° C.
Where it takes time, the solubilization rate was 90 at 10 minutes at 85 ° C.
It can be confirmed that it exceeds%, and this time reduction is amazing.

[0060]

[Test Example 2] An experiment was conducted in which sewage having an S-COD concentration of 15 ppm was placed in a beaker and heated by a heater.
The temperature was maintained by operating the heater switch every 10 to 20 minutes so that the temperature was maintained in the range of 85 to 95 ° C. Since the inside of the beaker is agitated by convection, it was sometimes agitated manually to compensate for the agitation.

The following results were obtained in this experiment. (1) 10 minutes S-COD 380p
pm: Solubilization rate 96% [Calculation formula of this solubilization rate: (380-15) ÷ 380 =
96] (2) 30 minutes S-COD 790p
pm: Solubilization rate 98.1% (3) 10 minutes using caustic soda S-COD1300p
pm: Solubilization rate 98.8% (4) 10 minutes with caustic soda S-COD1800p
pm: Solubilization rate 99.1%

Conventionally, it takes about 6 hours to perform S-C processing.
The OD was 430 ppm: the solubilization rate was 96.5%, and in this experiment, it was confirmed that sufficient treatment could be performed in about 10 minutes. Therefore, according to the present invention, the solubilization rate can be increased to 90% or more even if the temperature is set to 85 ° C. for 10 minutes, and the sludge treatment capacity can be significantly improved.

[0063]

[Test Example 3] An experiment was conducted in which sewage having an S-COD concentration of 75 ppm was placed in a beaker and heated by a heater.
The temperature was maintained by operating the heater switch every 10 to 20 minutes so that the temperature was maintained in the range of 85 to 95 ° C. (1) 10 minutes S-COD 380
ppm: Solubilization rate 80% (2) 10 minutes Using caustic soda S-COD1300
ppm: Solubilization rate 94% In this experiment, when caustic soda was used, the higher the temperature, the higher the S-COD value was found, and it was found that a great effect can be expected.

[0064]

TEST EXAMPLE 4 Sewage having an S-COD concentration of 15 ppm was put in a container, and the temperature was simply raised to conduct an experiment in the case of a thermophilic bacterium.

The results show that (1) the solubilization rate is 10 when treated at 20 ° C. for 48 hours.
% (2) When treated at 50 ° C for 48 hours, the solubilization rate is 28
% (3) When treated at 70 ° C for 48 hours, the solubilization rate is 30
% (4) Solubilization rate is 30 when treated at 80 ℃ for 48 hours.
% Met.

For reference, the case of mesophilic bacterium was examined. The results were (5) when treated at 20 ° C. for 48 hours, and solubilization rate was 3% (6) when treated at 80 ° C. for 1 hour. Solubilization rate is 15
% (7) When treated at 80 ° C for 24 hours, the solubilization rate is 15
% (8) When treated at 80 ° C for 48 hours, the solubilization rate is 15
% Met.

In this experiment, even if the microbial treatment was a thermophilic bacterium, the solubilization rate was 30 when treated at 80 ° C. for 48 hours.
%, The value was 15%, and in the case of mesophilic bacterium, the value of 15% when treated for 1 hour did not change even after many hours. Therefore, in the microbial treatment, the solubilization rate cannot be increased even if the temperature is increased, and if the temperature is further increased, the solubilization rate is killed and the solubilization rate is lowered.

[0068]

[Test Example 5] A comparative experiment was carried out in which sewage having an S-COD concentration of 15 ppm was put in a container to examine changes in S-COD at a low temperature and a high temperature. As a result, the S-COD and the solubilization rate were as follows.

[0069]       Temperature range Presence of caustic soda S-COD (ppm) Solubilization rate (%)   (1) Before processing 75   (2) 25-35 ° C 68   (3) 25-35 ° C Use caustic soda 72   (4) 35-45 ° C 69   (5) 35-45 ° C Use caustic soda 72   (6) 45-55 ° C 110 31.8   (7) 45-55 ° C Use caustic soda 230 67.3   (8) 55-65 ° C 230 67.3   (9) 55-65 ° C Using caustic soda 240 68.7   (10) 65-75 ° C 270 72.2   (11) 65-75 ° C Using caustic soda 340 77.9   (12) 75-85 ° C 290 74.1   (13) 75-85 ℃ Using caustic soda 360 79.1   (14) 85-95 ° C 380 80.0   (15) 85-95 ° C Using caustic soda 1300 94.2

From the results of this experiment, it was found that the solubilization rate becomes about 70% at 55 to 65 ° C. or higher, and the effect can be expected sufficiently. Moreover, the solubilization rate is 80 unless the power of caustic soda is high in the high temperature range of 85 to 95 ° C.
%, But 94.2% due to the use of caustic soda
And the solubilization rate could be improved significantly.

[0071]

The present invention is as described above. Before entering the sewage treatment process by microorganisms, the organic sludge is heated to 55 ° C to 98 ° C.
By simultaneously boiling the mixture at high temperature and mixing it by passing it through the mixing pipe 1, the cell wall of biological origin contained in the sewage is dissolved / destroyed, and the dissolution efficiency of organic substances is synergistically increased, and the solubilization rate is increased. To obtain 90% or more, processing can be carried out for an extremely short time, which is 5 to 10 times faster than before. Further, by adding sodium hydroxide, a surfactant or an enzyme agent to the wastewater during mixing or before mixing, the dissolution efficiency can be further increased.

Further, the mixing by the mixing pipe greatly increases the dissolved oxygen concentration in the wastewater D and promotes the consumption of oxygen by the aerobic microorganisms in the wastewater treatment tank by the microorganisms, which is extremely active. To decompose organic substances. Therefore, the load on the sewage treatment capacity of the sewage treatment tank is significantly reduced. As a result, even if sewage exceeds the treatment capacity of various sewage purification systems equipped with microbial wastewater treatment tanks for treating organic sewage such as industrial wastewater of hotels and restaurants, the present invention By pre-processing the above, it became possible to fully cope with the equipment.

Further, according to this method, the apparatus can be made extremely compact and the temperature can be easily controlled without boiling or pressurizing, so that the facility cost and the management cost can be greatly reduced. became.

[Brief description of drawings]

FIG. 1 is a flowchart showing the processing steps of the present invention.

FIG. 2 is a flowchart showing a processing step of another embodiment.

FIG. 3 is a schematic vertical sectional side view of an apparatus used in the present invention.

FIG. 4 is a schematic vertical sectional side view of another device.

FIG. 5 is a schematic vertical sectional side view of another device.

FIG. 6 is a schematic vertical sectional side view of another device.

FIG. 7 is a schematic vertical sectional side view of another device.

FIG. 8 is a schematic vertical sectional side view of another device.

FIG. 9 is a schematic vertical sectional side view of another device.

FIG. 10 is a schematic vertical sectional side view of another device.

FIG. 11 is a schematic vertical sectional side view of another device.

FIG. 12 is a schematic vertical sectional side view of another device.

FIG. 13 is a schematic vertical sectional side view of another device.

[Explanation of symbols]

1 mixing pipe 2 stew tank 3 heater 4 pumps 5 water pipe 6 Return pipe 7 Microbial persistent solid matter removal device 8 water pipes 9 water pipe 10 Sewage treatment tank 11 water pipe 12 pumps 13 stirring tank 14 water pipe 15 pumps 16 Mixing pipe water discharge pipe 17 water pipe 18 pumps 19 heater 20 Air injection pipe 21 stirring circulation tank 22 Stirrer 23 Stirring motor G raw water D dirty water W water S Sewage treatment system

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Claims (17)

[Claims] 1. In the method for treating sewage in a microbiological process, when the fluidity of the raw sewage is low, water is added to the raw sewage during or after being introduced into the boiling tank so that the BOD concentration is about 10,000 ppm or less. After increasing the fluidity by diluting the sewage and controlling the temperature of the sewage by heating it to 55 ° C to 98 ° C, the sewage in the simmering tank is withdrawn and stirred,
Continuing stirring and returning to the stewing tank again, after sludge is solubilized in the stewing tank, the stewed wastewater is transferred to a decomposition treatment step by microorganisms Processing method. 2. In the method for treating sewage in a microbiological process, when the fluidity of the raw sewage is low, water is added to the raw sewage during the introduction into the boiling tank or in the boiling tank so that the BOD concentration is about 10,000 ppm or less. After increasing the fluidity by diluting the sewage and controlling the temperature of the sewage by heating it to 55 ° C to 98 ° C, the sewage in the simmering tank is withdrawn and stirred,
Continuing the stirring circulation to return it back into the boiling tank, and after the sludge becomes solubilized in the boiling tank, the boiling wastewater is mixed with the injected air by passing through the mixing pipe. Then, the method for sewage treatment of sewage is characterized in that it is transferred to a decomposition treatment step by microorganisms. 3. A method for stirring sewage used for stirring and circulating, in which sewage in a boiling tank is extracted, pressure-fed, and passed through a mixing pipe to be mixed in the mixing pipe, and then returned to the boiling tank. The sewage sewage treatment method according to claim 1 or 2, which is a stirring circulation. 4. A method for stirring sewage used for stirring and circulating, wherein the sewage in the simmering tank is withdrawn and pressure-fed, and the sewage is mixed with the injected air in the mixing pipe, and then mixed in the mixing pipe. The sewage sewage treatment method according to claim 1 or 2, which is a stirring circulation for returning the inside. 5. The stirring method for stirring and circulating used sewage is as follows: the sewage in the boiling tank is drawn out, introduced into the stirring circulating tank, stirred at a high speed in the stirring circulating tank, and then returned to the stirring tank. The sewage sewage treatment method according to claim 1 or 2. 6. A method of stirring sewage used for stirring circulation, in which the sewage in the boiling tank is drawn out and introduced into the stirring circulation tank, the stirring circulation tank is stirred at high speed, and the sewage in the stirring circulation tank is extracted. By pumping it and passing it through a mixing pipe to mix it in the mixing pipe and then returning it to the stirring circulation tank, stirring circulation is carried out, and the stirred wastewater in the stirring circulation tank is returned to the boiling tank. The method according to claim 1 or 2, which is a stirring circulation.
The sewage sewage treatment method described in. 7. The sewage treatment method according to claim 5, wherein the temperature of the wastewater in the stirring circulation tank is adjusted to 55 ° C. to 98 ° C when the stirring circulation tank is stirred at a high speed. 8. In the method for treating sewage in a microbiological process, when the fluidity of the raw sewage is low, water is added to the raw sewage in a stirring tank to bring the BOD concentration to about 1 before being introduced into the boiling tank.
Dilute it to 0000 ppm or less to increase fluidity and stir the wastewater in the stirring tank, introduce the stirring-treated wastewater into the boiling tank and heat the wastewater to adjust the temperature to 55 ° C to 98 ° C. A method for sewage treatment of sewage, wherein after the sludge becomes solubilized in the sewage tank, the sewage sewage is transferred to a decomposition treatment step by microorganisms. 9. In the method of treating sewage in a microbiological process, when the fluidity of the raw sewage is low, water is added to the raw sewage in a stirring tank to bring the BOD concentration to about 1 before being introduced into the boiling tank.
Dilute it to 0000 ppm or less to increase fluidity and stir the wastewater in the stirring tank, introduce the stirring-treated wastewater into the boiling tank and heat the wastewater to adjust the temperature to 55 ° C to 98 ° C. After the sludge becomes solubilized in the stewing tank, the stewed sewage is allowed to pass through a mixing pipe together with the injected air to be mixed in the mixing pipe and then transferred to a microbial decomposition treatment step. Characterizing sewage sewage treatment method. 10. A method for stirring sewage in a stirring tank is such that the sewage in the stirring tank is extracted, pressure-fed, and passed through a mixing pipe to be mixed in the mixing pipe and then into the stirring tank. The sewage treatment method of sewage according to claim 8 or 9, which is a stirring circulation for returning. 11. A method for stirring sewage in a stirring tank, which comprises extracting the sewage in the stirring tank by pressure, and passing the sewage into the mixing pipe together with the injected air, and then mixing in the mixing pipe. The sewage sewage treatment method according to claim 8 or 9, which is a stirring circulation in which the waste water is returned to the stirring tank. 12. The sewage sewage treatment method according to claim 8, wherein the sewage in the stirring tank is stirred at a high speed. 13. The mixing method of stirring sewage in a stirring tank is as follows. The method of stirring sewage in a stirring tank is as follows: The sewage in the stirring tank is extracted, pressure-fed, and passed through a mixing pipe. The sewage according to claim 8 or 9, characterized in that the sewage water is mixed in the agitation tank and then returned to the agitation tank, and the sewage in the agitation tank is agitated at a high speed. Stew processing method. 14. The sewage of sewage according to claim 8, wherein the sewage in the agitation tank is temperature-controlled to 55 ° C. to 98 ° C. when the sewage is agitated in the agitation tank. Processing method. 15. A method of stirring sewage in a stirring tank, wherein the sewage in the stirring tank is stirred at a low speed for several minutes while controlling the temperature at 55 ° C. to 98 ° C., and then the sewage in the stirring tank is stirred. The sewage of sewage according to claim 8 or 9, characterized in that the sewage is pumped out, pumped, and passed through a mixing pipe to perform mixing and circulation in the mixing pipe before returning the mixture to the stirring tank. Processing method. 16. The sewage according to any one of claims 1 to 15, wherein sodium hydroxide, a surfactant or an enzyme agent is added to the sewage during stirring or before stirring. Stew processing method. 17. The microbial hardly decomposable solid matter contained in the wastewater is removed before the wastewater is passed through the first mixing pipe.
5, 6, 7, 9, 10, 11, 13, 14, 15, 16
The method for boiling sewage according to any one of the above.