JP4120859B2 - Organic injection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic substance injecting apparatus that can cope with fluctuations in the concentration of organic substances in inflow water due to rainfall or the like.
[0002]
[Prior art]
FIG. 2 is a diagram illustrating the configuration of a conventional example that is generally used.
In the figure, 1 is an initial settling basin into which sewage A flows.
2 is a biological reaction tank into which the sewage A first treated by the settling basin 1 is introduced and has an anaerobic tank 3.
[0003]
4 is a final sedimentation basin into which sewage A treated by the biological reaction tank 2 flows.
Reference numeral 5 denotes an initial settling sludge extraction introduction pipe that allows the first settling tank 1 and the anaerobic tank 3 to communicate with each other.
A return sludge pipe 6 communicates the final sedimentation basin 4 and the anaerobic tank 3.
In addition, the first sedimentation sludge B of the first sedimentation basin 1 and the excess sludge C of the final sedimentation basin 4 are discharged outside.
[0004]
In the above configuration, biological phosphorus removal is a treatment method in which an anaerobic part and an aerobic part are provided in a sewage / sewage treatment apparatus, and the phosphate release and overdose properties of phosphorus accumulating bacteria are used.
[0005]
Biological phosphorus removal has a problem in that phosphorus cannot be treated well in a treatment facility or a treatment apparatus when the concentration of organic substances in the inflowing water is reduced due to rain or the like.
It has been reported in the literature that this decrease in phosphorus removal ability occurs when there is a shortage of organic acids or fermentable substrates that can be used by phosphorus accumulating bacteria.
[0006]
In order to compensate for the shortage of organic acids and fermentable substrates in the influent water, the following methods have been reported.
(1) The first settling sludge is put into an anaerobic tank.
(2) Bypassing the initial sedimentation, inflowing water is thrown into the anaerobic tank.
(3) An acid fermentation tank is provided, and the fermented liquid is introduced into the anaerobic tank.
[0007]
[Problems to be solved by the invention]
However, such an apparatus has the following problems.
(1) The first settling sludge is put into an anaerobic tank.
Most of the first settling sludge is floating organic matter, and is organic matter that is difficult for microorganisms to ingest in the biological reaction tank 2.
[0008]
The effect immediately after the initial settling sludge is introduced is limited.
In addition, when sludge is continuously charged, there is a possibility of excessively increasing the BOD load in the treatment facility or treatment apparatus.
[0009]
(2) Bypassing the initial sedimentation, inflowing water is thrown into the anaerobic tank.
Since the organic matter is not removed in the initial precipitation, the concentration of the organic matter flowing into the biological reaction tank 2 increases.
However, the effect of the bypass is limited because the organic matter concentration is dilute in the rain.
[0010]
(3) An acid fermentation tank is provided, and the fermented liquid is introduced into the anaerobic tank.
The organic matter obtained by acid-fermenting the first settling sludge is considered to have a large effect of adding the fermentation liquor because organic acids, fermentable substrates and the like are increasing.
However, since an installation space for the acid fermenter is required, it is limited to a case where there is a margin in the site area.
[0011]
In addition to the biological phosphorus removal method, there is a chemical phosphorus removal method. The chemical phosphorus removal method is a method in which a coagulant such as PAC is injected into the end of the aerobic tank, and phosphorus is coagulated and precipitated in the final precipitation.
As an advantage, it is possible to reliably remove phosphorus by using an appropriate injection rate.
On the other hand, as a disadvantage, an increase in the amount of sludge generation and the inclusion of aluminum salts are problematic.
[0012]
The object of the present invention is to solve the above-mentioned problems, and in the removal of biological phosphorus, when the organic matter concentration in the inflow water is lowered due to rainfall or the like, the microorganisms are used by using the initial settling sludge and the excess sludge. It is an object of the present invention to provide an organic substance injecting apparatus for producing an organic substance that can be easily fermented and an organic substance that can be easily fermented in an anaerobic tank in a short time and optimally injecting it.
[0013]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, in the organic substance injection device according to claim 1,
Organic matter comprising a first sedimentation basin into which sewage is introduced, a bioreactor having an anaerobic tank into which sewage treated by the first sedimentation basin is introduced, and a final sedimentation basin into which sewage is introduced from this bioreactor In the injection device,
A sludge refining device in which the return sludge from the final sedimentation basin flows in, and a part of the initial sedimentation sludge from the first sedimentation basin flows in and the refined sludge flows out to the anaerobic tank ; A low-molecular-weight organic substance measuring device that is provided in a sedimentation basin and measures a low-molecular-weight organic substance, and a control device that controls the amount of sludge that is input from the sludge refiner to the anaerobic tank based on a signal from the low-molecular-weight organic substance measuring device It was characterized by comprising.
[0014]
According to claim 2 of the present invention, in the organic substance injection device according to claim 1,
A BOD meter is used as the low molecular organic substance measuring device.
[0015]
In claim 3 of the present invention, in the organic substance injection device according to claim 1,
An organic acid meter is used as the low molecular organic substance measuring device.
[0016]
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view of the main part configuration of an embodiment of the present invention.
In the figure, the same symbol structure as in FIG. 2 represents the same function.
Only the differences from FIG. 2 will be described below.
[0017]
In the figure, reference numeral 11 denotes a sludge refinement device provided in the middle of the initial settling sludge extraction introduction pipe 5.
The sludge refiner 11 crushes, refines and solubilizes slow biodegradable substances and microorganism cell walls in the sludge.
[0018]
Reference numeral 12 denotes a low-molecular-weight organic substance measuring apparatus that is provided in the first sedimentation basin and measures low-molecular-weight organic substances.
In this case, an organic acid meter is used as a low molecular organic substance measuring apparatus.
[0019]
Reference numeral 13 denotes a control device that controls the operation of the sludge refiner 11 based on a signal from the low-molecular-weight organic substance measuring device 12.
Reference numeral 14 denotes a return sludge introduction pipe having one end communicating with the return sludge pipe 6 and the other end communicating with the sludge refiner 11.
[0020]
In the above configuration, the organic acid meter 12 continuously monitors the organic acid concentration of the inflow water of the biological reaction tank 2.
When the organic acid concentration falls below the reference value, the operation of the sludge refiner 11 is started.
[0021]
It is reported that the concentration of phosphorus in treated water often deteriorates when the concentration of organic acid is 15 mg / l or less at a treatment plant in municipal sewage.
The reference value varies depending on the processing facility and processing apparatus, but this value is about 15 mg / l.
[0022]
In accordance with the organic acid concentration, the control device 11 controls the amount of sludge that is introduced from the sludge refiner 11 into the anaerobic tank 3.
When the organic acid concentration recovers to the reference value or higher, the control device 11 stops the operation of the sludge refiner 11.
[0023]
As a result,
(1) Since an organic substance that can be easily used by microorganisms and an organic substance that can be easily fermented in an anaerobic tank can be generated in a short time, an organic substance injecting apparatus that can improve the quality of treated water even during rainfall can be obtained.
[0024]
(2) In removing phosphorus during rainfall, waste such as first settling sludge can be effectively used without using chemicals, and an environmentally friendly organic substance injection device can be obtained.
[0025]
It should be noted that the above description merely shows a specific preferred embodiment for the purpose of explaining and illustrating the present invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.
[0026]
【The invention's effect】
As described above, according to Claims 1 and 2 of the present invention, the following effects can be obtained.
Based on the sludge refining device provided in the middle of the initial settling sludge extraction introduction pipe, the low molecular organic matter measuring device for measuring low molecular organic matter provided in the first sedimentation basin, and the signal from the low molecular organic matter measuring device A control device for controlling the operation of the sludge refiner and a return sludge introduction tube having one end communicating with the return sludge tube and the other end communicating with the sludge refiner.
[0027]
Therefore,
(1) Since an organic substance that can be easily used by microorganisms and an organic substance that can be easily fermented in an anaerobic tank can be generated in a short time, an organic substance injecting apparatus that can improve the quality of treated water even during rainfall can be obtained.
[0028]
(2) In removing phosphorus during rainfall, waste such as first settling sludge can be effectively used without using chemicals, and an environmentally friendly organic substance injection device can be obtained.
[0029]
According to claim 2 of the present invention, there are the following effects.
(1) An organic substance injection device capable of minimizing the power consumption of the sludge refiner can be obtained.
(2) An organic substance injection device capable of minimizing an increase in BOD load due to sludge input, that is, optimum sludge injection can be obtained.
[0030]
According to claim 3 of the present invention, there are the following effects.
Since the organic acid meter is used as the low molecular organic substance measuring apparatus, the low molecular organic substance itself can be directly and accurately measured, and thus an organic substance injection apparatus with improved accuracy can be obtained.
[0031]
Therefore, according to this invention, the organic substance injection | pouring apparatus which can respond to the fluctuation | variation of the organic substance density | concentration in inflow water by rainfall etc. is realizable.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a main part configuration of a conventional example generally used conventionally.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 First sedimentation tank 2 Biological reaction tank 3 Anaerobic tank 4 Final sedimentation tank 5 Initial sedimentation sludge extraction introduction pipe 6 Return sludge pipe 11 Sludge refinement device 12 Low molecular organic substance measurement device 13 Control device 14 Return sludge introduction pipe A Sewage B First sedimentation Extracted sludge C Surplus sludge

Claims (3)

The first sedimentation basin into which sewage flows,
A biological reaction tank having an anaerobic tank into which the sewage treated by the first sedimentation basin is introduced;
In the organic material injection device comprising: a final sedimentation basin into which sewage from the biological reaction tank flows.
The sludge refining device in which the returned sludge from the final sedimentation basin is flowed in, and a part of the initial sedimentation sludge from the first sedimentation basin is flowed in and the refined sludge is discharged to the anaerobic tank ,
A low-molecular-weight organic substance measuring apparatus that is provided in the first sedimentation basin and measures low-molecular-weight organic substances;
An organic substance injection device comprising: a control device that controls the amount of sludge to be introduced from the sludge refiner to the anaerobic tank based on a signal from the low molecular organic substance measuring device. 2. The organic substance injection device according to claim 1, wherein a BOD meter is used as the low molecular organic substance measurement device. 2. The organic substance injecting apparatus according to claim 1, wherein an organic acid meter is used as the low molecular organic substance measuring apparatus.

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