JP4147381B2 - Method and apparatus for treating peroxide-containing wastewater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, the processing method of the peroxide-containing wastewater and apparatus, and more particularly to a method and an apparatus for processing waste water you containing a peroxide such as hydrogen peroxide or peracetic acid.
[0002]
[Prior art]
In recent years, in food factories and the like, peroxides such as hydrogen peroxide and peracetic acid have been used from the viewpoint of strict sterilization when producing drinking water and food. Specifically, such a peroxide such as hydrogen peroxide is used for cleaning for sterilizing a lid of a plastic bottle containing drinking water, for example.
[0003]
In such wastewater, organic substances may be contained in addition to the above-described peroxides. In such cases, biological treatment may be performed using microorganisms in the same manner as organic substances in general wastewater. desirable. Further, when peracetic acid is used as the peroxide, the peracetic acid changes to acetic acid after the addition, but since the acetic acid is also an organic substance, it is desirable to perform biological treatment.
[0004]
However, since hydrogen peroxide, peracetic acid, and the like have a bactericidal action, they have an inhibitory effect on microorganisms. Therefore, when wastewater containing peroxide as described above is biologically treated as it is, It will die and the biological treatment will not be effective.
[0005]
Therefore, it is necessary to decompose the peroxide as described above in advance. As the means, conventionally, for example, a method using a reducing agent such as sodium bisulfite, sodium thiosulfate or an iron compound, or a catalyst such as activated carbon is used. The method using is adopted.
[0006]
[Problems to be solved by the invention]
However, in the method using a reducing agent, since the reducing agent itself is relatively expensive, there is a problem in that the entire treatment cost is increased, and the amount of sludge in the subsequent stage is increased by the amount of addition of the reducing agent. .
[0007]
In addition, the method using activated carbon can reduce the cost as compared with the method using a reducing agent, but requires a separate apparatus for supporting activated carbon as a catalyst. Moreover, when the reaction in which the peroxide is decomposed occurs, the activated carbon may foam and flow out.
[0008]
The present invention has been made to solve such a conventional problem, and enables biological treatment by decomposing peroxide in wastewater without requiring a reducing agent, a catalyst, or the like. This is a problem.
[0009]
[Means for Solving the Problems]
The present invention, in order to solve such problems, has been made as a processing method and apparatus for you containing a peroxide such as hydrogen peroxide or peracetic acid peroxide-containing wastewater, containing peroxide The characteristic of the wastewater treatment method is that the wastewater to be biologically treated is anaerobically treated with an upflow type anaerobic treatment facility, and then the anaerobic treated water is mixed with the peroxide-containing wastewater. It is to decompose the peroxide.
[0010]
Also, features of the apparatus of peroxide-containing wastewater is treated wastewater to be biological treatment with anaerobic treatment facility second upflow for anaerobic treatment, anaerobic treatment equipment 2 of the upflow And a mixing tank 4 for mixing the anaerobic treated water with the peroxide-containing waste water.
[0011]
An aerobic treatment facility 5 is provided at the subsequent stage of the mixing tank 4, and the mixed waste water of the anaerobic treated water and the peroxide-containing waste water after decomposing the peroxide in the peroxide-containing waste water is aerobic. It is desirable to be biologically treated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
(Embodiment 1)
FIG. 1: shows the schematic block diagram of the processing apparatus of the peroxide containing waste_water | drain as one Embodiment.
[0014]
The peroxide-containing wastewater treatment apparatus of the present embodiment, as shown in the figure, is a food factory wastewater storage tank 1, an anaerobic treatment facility 2, a peroxide-containing wastewater storage tank 3, a mixing tank 4, An aerobic treatment facility 5.
[0015]
The food factory wastewater storage tank 1 is a wastewater discharged from a food factory, and is used to supply and store general wastewater, which is a beverage, an unnecessary food product, and other liquid materials that cannot be commercialized, from the food factory. belongs to.
[0016]
The anaerobic treatment facility 2 is for treating the wastewater from the food factory wastewater storage tank 1 by anaerobic treatment. For example, the anaerobic treatment facility 2 decomposes and treats organic matter in the wastewater with methane fermentation bacteria or the like.
[0017]
As such anaerobic treatment equipment 2, for example, an upflow anaerobic treatment equipment (UASB) is used. The anaerobic treatment facility 2 is provided with a reaction tank (not shown) filled with cell granules of methane fermentation bacteria, and the waste water from the food factory waste water storage tank 1 is supplied from the bottom of the reaction tank. Will be.
[0018]
The peroxide-containing waste water storage tank 3 is for storing waste water after washing containers and their lids using cleaning water for cleaning and sterilization containing hydrogen peroxide in a food factory. . The wastewater contains peroxide as a biological inhibitory component.
[0019]
The mixing tank 4 is a tank for mixing the anaerobic treated water that has been anaerobically treated by the anaerobic treatment equipment 2 and the peroxide-containing waste water from the peroxide-containing waste water storage tank 3. Thus, hydrogen peroxide, which is a peroxide in the peroxide-containing wastewater, is decomposed by the anaerobic treated water.
[0020]
The aerobic treatment facility 5 is for aerobically biologically treating the mixed waste water in which the peroxide is decomposed in the mixing tank 4, and for example, an activated sludge method is employed.
[0021]
Although not shown, the aerobic treatment facility 5 by the activated sludge method is provided with a biological treatment tank, a sedimentation tank, and the like, and the biological treatment tank is filled with a carrier as necessary.
[0022]
Embodiment of the processing method which processes the peroxide containing waste_water | drain discharged | emitted from a food factory using the processing apparatus of the peroxide containing waste water which consists of the above structures is demonstrated.
[0023]
First, the general waste water discharged from the food factory is stored in the food factory waste water storage tank 1, and the waste water is supplied from the food factory waste water storage tank 1 to the anaerobic treatment facility 2. The organic matter in the waste water is decomposed and anaerobically treated by the cell granules of the methane fermentation bacteria in the reaction tank in the anaerobic treatment facility 2.
[0024]
Next, the anaerobic treated water that has been anaerobically treated by the anaerobic treatment facility 2 is supplied to the mixing tank 4. On the other hand, the peroxide-containing waste water is supplied from the peroxide-containing waste water storage tank 3 to the mixing tank 4.
[0025]
Then, the anaerobic treated water and the peroxide-containing waste water are mixed in the mixing tank 4, and the hydrogen peroxide in the peroxide-containing waste water is decomposed by the anaerobic treated water.
[0026]
The action of hydrogen peroxide being decomposed by the anaerobic treated water is not necessarily clear, but it is recognized that it is decomposed by the reducing power of the anaerobic treated water. And the concrete effect | action in the case of methane fermentation is estimated as follows once.
[0027]
In biological treatment, electrons are exchanged with respect to the decomposition of organic substances, that is, oxidation and reduction reactions are sequentially performed and the reaction proceeds.
[0028]
A high-energy compound such as ATP is necessary for the microorganisms used in biological treatment to survive, but the energy necessary to produce such a high-energy compound is obtained by oxidation of organic matter. At that time, electrons are emitted, so an electron acceptor is required.
[0029]
In anaerobic wastewater treatment, there is no dissolved oxygen and there is no efficient electron acceptor (the one that receives the electrons released by the oxidation step), so carbon dioxide is used to receive the electrons released by methane bacteria. Is done.
In other words, carbon dioxide is reduced by hydrogen, resulting in the production of methane.
[0030]
In addition, when sulfate is present, the reaction is reduced by hydrogen and organic matter to generate hydrogen sulfide. Considering the progress of such a reaction, it can be said that the anaerobic treated water is water having a high reducing power.
[0031]
The mixed waste water in which hydrogen peroxide is decomposed in the mixing tank 4 in this way is supplied to the aerobic treatment facility 5. The mixed waste water is sequentially supplied to the biological treatment tank and the sedimentation tank of the aerobic treatment facility 5 and is aerobically biologically treated.
[0032]
The organic matter in the wastewater from the food factory is not completely decomposed only by the anaerobic treatment by the anaerobic treatment equipment 2, but is further decomposed by the subsequent aerobic treatment equipment 5, so that the BOD in the wastewater is also reduced. It can be done.
[0033]
As described above, in this embodiment, the general wastewater discharged from the food factory is anaerobically treated, and the bioinhibitory component in the peroxide-containing wastewater is utilized by utilizing the reducing power of the anaerobic treated water after the anaerobic treatment. Some hydrogen peroxide could be decomposed.
[0034]
Therefore, it becomes possible to treat peroxide-containing wastewater by directly using a general wastewater treatment system from a food factory without separately preparing a reducing agent, a catalyst and the like as in the past.
[0035]
(Embodiment 2)
As shown in FIG. 2, the peroxide-containing wastewater treatment apparatus according to the present embodiment includes an anaerobic treatment facility 2, a mixing tank 4, and an aerobic treatment facility 5. The food factory wastewater storage tank 1 and the peroxide-containing wastewater storage tank 3 are not provided.
[0036]
That is, in this embodiment, the wastewater discharged from the food factory is directly supplied to the anaerobic treatment facility 2, and the peroxide-containing wastewater after being used as cleaning water for cleaning and sterilization in the food factory is Directly supplied to the mixing tank 4.
[0037]
However, the wastewater from the food factory is supplied to the anaerobic treatment facility 2 and anaerobically treated by the cell granules of the methane fermentation bacteria, and the anaerobic treated water after the anaerobic treatment is mixed with the peroxide-containing wastewater in the mixing tank 4. Embodiment 1 is that the hydrogen peroxide in the peroxide-containing wastewater mixed is decomposed by the anaerobic treated water, and the mixed wastewater in which the peroxide is decomposed is aerobically treated in the aerobic treatment equipment 5. Is the same.
[0038]
Also in the present embodiment, after the general waste water discharged from the food factory is anaerobically treated as in the first embodiment, the hydrogen peroxide in the peroxide-containing waste water is reduced using the reducing power of the anaerobic treated water. Can be disassembled.
[0039]
(Other embodiments)
In the above embodiment, since the aerobic treatment equipment 5 is provided in the subsequent stage of the mixing tank 4, organic substances that could not be sufficiently decomposed by the anaerobic treatment equipment 2 can be suitably decomposed, and in the peroxide-containing waste water. However, the provision of such aerobic treatment equipment 5 is not an essential condition for the present invention.
[0040]
Moreover, in this embodiment, the mixing tank 4 is provided in the back | latter stage of the anaerobic treatment equipment 2, and the peroxide containing waste water is supplied to the mixing tank 4, and this peroxide containing waste water and anaerobic treated water are mixed. However, the provision of the mixing tank 4 is not an essential condition for the present invention. For example, it is also possible to supply the peroxide-containing wastewater directly to the line behind the anaerobic treatment facility 2 and mix it with the anaerobic treated water. In short, the peroxide-containing waste water and the anaerobic treated water may be mixed.
[0041]
Furthermore, in this embodiment, although the case where the waste_water | drain containing hydrogen peroxide was applied was demonstrated, it is also possible to apply this invention to the waste_water | drain containing peracetic acid. In short, the present invention can be applied to any wastewater containing these peroxides.
Furthermore, in the above-described embodiment, the case where the peroxide-containing wastewater is mixed with the food factory wastewater is described, but the type of wastewater to which the present invention is applied is not limited to the food factory wastewater of the embodiment, It can also be applied to various types of wastewater.
[0043]
【Example】
(Example 1)
In this example, the hydrogen peroxide-containing wastewater containing hydrogen peroxide, which is a biological inhibitory component, and anaerobic treated water were mixed at a ratio of 1: 1, and the concentration of hydrogen peroxide after a predetermined time was measured by stirring. .
[0044]
After 250 ml of hydrogen peroxide-containing wastewater was put in a container and the pH was adjusted to neutral, 250 ml of anaerobic water was added and stirred, and the concentration of hydrogen peroxide after a predetermined time was measured.
[0045]
Three types of anaerobic treated water were prepared: one after 2 days from sampling, one after 3 days, and one after 4 days. The test results are shown in FIG.
[0046]
As is apparent from FIG. 3, the concentration of hydrogen peroxide was about 1000 mg / l immediately after mixing all three types of samples, but it decreased to about 6 mg / l after 90 minutes.
[0047]
(Example 2)
In this example, an activated sludge batch test of anaerobic treated water obtained by decomposing hydrogen peroxide in Example 1 was performed. This is performed in order to confirm the biodegradability of the anaerobic treated water after the hydrogen peroxide decomposition treatment.
[0048]
Necessary amounts of nitrogen and phosphorus were added to treated water obtained by decomposing hydrogen peroxide with anaerobic treated water, sludge was added, and the TOC of the treated water was measured.
The result is shown in FIG.
[0049]
As is clear from FIG. 4, the TOC of anaerobic treated water decreased with the passage of time, and the TOC removal rate became 72% after 24 hours. Thereby, it was confirmed that biodegradation of the anaerobic treated water of Example 1 was possible.
[0050]
【The invention's effect】
As described above, according to the present invention, after anaerobic treatment of wastewater to be biologically treated, the anaerobic treated water is mixed with peroxide-containing wastewater to remove bioinhibitory components such as hydrogen peroxide in the peroxide-containing wastewater. Since it decomposes, there is an effect that it is possible to treat peroxide-containing wastewater by using a general wastewater treatment system as it is without separately preparing a conventional reducing agent or catalyst. is there.
[0051]
Therefore, there is an effect that the treatment cost for treating the peroxide-containing waste water can be reduced as compared with the conventional method using a reducing agent or a catalyst.
[0052]
Moreover, the amount of sludge derived from chemicals does not increase as in the prior art.
[0053]
Furthermore, after anaerobic treated water is mixed with peroxide-containing wastewater, when the mixed wastewater is aerobically treated, there is an effect that organic substances that cannot be decomposed only by anaerobic treatment can be suitably decomposed. .
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of an apparatus for treating peroxide-containing wastewater as one embodiment.
FIG. 2 is a schematic block diagram of a treatment apparatus for peroxide-containing wastewater as another embodiment.
FIG. 3 is a graph showing the transition of the oxidant concentration in peroxide-containing wastewater by the addition of anaerobic treated water.
FIG. 4 is a graph of the activated sludge circulation test result.
[Explanation of symbols]
2 ... Anaerobic treatment equipment 4 ... Mixing tank 5 ... Aerobic treatment equipment

Claims (5)

The wastewater to be biologically treated is anaerobically treated with an upflow anaerobic treatment facility, and then the anaerobic treated water is mixed with the peroxide-containing wastewater to decompose the peroxide in the peroxide-containing wastewater. processing method of peroxide-containing wastewater shall be the. After decomposing the peroxide in the peroxide-containing wastewater treatment method of peroxide-containing wastewater according to claim 1, wherein the biological treatment of mixed waste water with anaerobic treatment water and peroxide-containing wastewater. Biological treatment of mixed wastewater Ru aerobic biological treatment der 請 Motomeko 2 processing method of peroxide-containing wastewater as claimed. Anaerobic treatment facility upflow for anaerobic treatment of waste water to be biological treatment (2), and peroxide-containing wastewater the treated anaerobically treated water by anaerobic treatment facility of the upflow (2) mixing tank (4) and peroxide-containing wastewater treatment apparatus characterized by comprising the for mixing. Anaerobic treatment facility upflow for anaerobic treatment of waste water to be biological treatment (2), and peroxide-containing wastewater the treated anaerobically treated water by anaerobic treatment facility of the upflow (2) A mixing tank (4) for mixing, and a favorable condition for aerobic treatment of the mixed waste water of the anaerobic treated water mixed with the mixing tank (4) and the peroxide decomposed and the peroxide-containing waste water. air treatment facility (5) and the peroxide-containing wastewater treatment apparatus you characterized by comprising a.

Images