JP3047622B2 - Method and apparatus for treating wastewater containing hydrogen peroxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTIONHydrogen peroxide (H
_Two O _Two ), Hydrogen fluoride (HF), BOD components and nitrogen
To remove these substances from wastewater containing compounds
Method and equipment And more specifically, biological treatment of wastewater
To the extent harmless to the microbial sludge used.
Reduction and detoxification of hydrogen peroxide in water with microbial sludge
After that, the detoxified treated water is treated in the biological treatment step.
Along with the microbial sludge grown in this biological treatment process.
Effective use as microbial sludge for the treatment of hydrogen peroxide
And apparatus for treating hydrogen peroxide-containing wastewater
It is about.

[0002]

2. Description of the Related Art Although H ₂ O ₂ is used in various industrial fields, recently, it is combined with other inorganic chemicals especially in a wafer manufacturing process and a device forming process of a semiconductor manufacturing industry, and HF / H ₂ O ₂ , NH ₃ / H ₂ O ₂ , HCl /
H ₂ O ₂ is used in a large amount in a cleaning process with a structure such as H ₂ O ₂ . H ₂ O ₂ discharged in a large amount from these cleaning processes is hardly reduced in the cleaning process itself.
Almost the same amount flows into the wastewater treatment plant, is subjected to some reduction treatment, or is diluted to a level that has no effect and discharged. It is well known that about 3% of H ₂ O ₂ is used as a disinfectant and disinfectant, and if it is discharged without treatment, it will affect downstream organisms, and the H ₂ O ₂ wastewater will contain organic matter. In many cases, the treatment is performed in a biological treatment step, and such a system needs to remove H ₂ O ₂ to a harmless level before the biological treatment step.

There are theoretically various methods for decomposing H ₂ O ₂ , and the conventional general treatment methods are the following three methods. (1) Reduction method of H ₂ O ₂ by activated carbon Reaction formula: 2H ₂ O ₂ + C → CO ₂ + 2H ₂ O (2) Reduction method of H ₂ O ₂ by inorganic reducing chemicals Reaction formula: 2NaHSO ₃ + 2H ₂ O ₂ → Na ₂ SO ₄ +
H ₂ SO ₄ + 2H ₂ ONa ₂ SO ₃ + H ₂ O ₂ → Na ₂
SO ₄ + H ₂ O (3) Reduction method using an organic reducing agent Treatment is performed with a chemical containing H ₂ O ₂ degrading enzyme (sold by a water treatment chemical manufacturer). Reaction formula: 2H ₂ O ₂ + C → CO ₂ + 2H ₂ O

[0004]

In the case where H ₂ O ₂ is discharged to a wastewater treatment facility with a certain concentration and a fixed amount of water,
What is necessary is just to quantitatively add a small excess of the reducing agent to the H ₂ O ₂ reaction equivalent. If the H ₂ O ₂ waste water has a high concentration and a small amount of water, batchwise reliable treatment can be easily performed by the conventional method. However, in any wastewater, the water volume and concentration generally fluctuate greatly. It is not possible with common sense to have a huge buffer tank so that they can be adjusted evenly before the processing equipment. Generally, the peak value is often several tens of times the average concentration per day. Of the above three methods, the most common method uses NaHSO ₃ (sodium bisulfite). In this case, as a method to cope with inflow fluctuation,
Since an automatic monitor for detecting the presence of H ₂ O ₂ has not been developed yet, the only means is to control it with an oxidation-reduction potentiometer.

However, an oxidation-reduction potentiometer (hereinafter referred to as an ORP) indicates a correct potential only under neutral pH, and thus requires a reliable neutralization facility. However, the reaction with NaHSO ₃ has the disadvantage that reliable neutralization is usually difficult because H ₂ SO ₄ is produced. Na ₂ SO _{3 for} H ₂ SO
_Although there is no drawback of producing ₄ , the reason why Na ₂ SO ₃ is not adopted as a general means is that the cost of chemicals is high and because liquid products are not distributed in the market, equipment for dissolving is required. It is. As a replacement for these inorganic chemicals, a liquid chemical called H ₂ O ₂ degrading enzyme has recently been used. The advantage of the method using this chemical is that it does not require a large facility and only a simple injection facility is required. On the contrary, the half-life required for H ₂ O ₂ decomposition is 30 minutes, and it is almost complete. In order to carry out the reaction, a reaction time of 2 hours or more, that is, a reaction tank is required, and in the case where the inflow fluctuation is severe, the cost is increased more than the reaction equivalent. The method of sending H ₂ O ₂ wastewater to the activated carbon filling tank is the safest method. This method is different from the chemical treatment method in that it does not cause excessive running cost per H ₂ O ₂ reaction equivalent, but has a disadvantage that equipment cost is huge.

As described above, the current typical H ₂ O ₂ treatment methods have been introduced. However, each of these methods requires new capital investment, and the running cost is enormous in proportion to the inflow H ₂ O _2. . In addition, since there is no reliable H ₂ O ₂ monitor, an excessive amount of drug is usually injected. Otherwise, some H ₂ O ₂ leakage will be ignored. In any case, the method of using a large amount of added chemicals is extremely unreasonable as a wastewater purification process from the viewpoint of not only cost but also the global environment. That is, under the name of treatment, a conventional wastewater treatment means that uses an additive for treatment and completely ignores the increase in salt content due to the treatment is not the best not only in terms of cost but also in terms of global environment. Activated carbon is a good method in that no additional chemicals are used, but it is not the best in terms of consuming as much energy as new carbon production for regeneration.

Conventionally, H ₂ O ₂ , HF and organic acids (BO
D) and wastewater containing nitrogen compounds
When removing water pollutants comprehensively, use H ₂ O ₂ treatment
And the biological treatment function of wastewater is greatly affected by H ₂ O ₂
Process of BOD components and nitrogen compounds
Is a big issue.

By the way, according to the literature concerning biological treatment of waste water, BOD removal only of the leakage of H ₂ O ₂ that it aerobic bacteria but there appears to be cases that it is not much affected, details that it how There is no such case. In many cases, nitrifying bacteria have a large inhibition. Practices for de-N is small, the leakage amount of H ₂ O _2, it is evident that de N efficiency decreases. In addition, it is said that bacteria are not affected in normal biological treatment because they are of the floating mixed type. However, in the case of a biofilm attached method such as a circular disc method, there is a case where the biofilm is peeled off due to leakage of H ₂ O _2. Many. Although there are few cases of H ₂ O ₂ leakage in biological treatment as described above, it can be said that the leak should be minimum for biological treatment.

The present invention has been made to solve the above-mentioned problems, and has as its object the simple operation of the H ₂ O ₂ , HF, BOD component and nitrogen compound in an extremely short time and at low cost .
These water pollutants from wastewater containing
An object of the present invention is to provide a method and an apparatus for treating wastewater containing hydrogen peroxide that can be removed .

[0010]

Means for Solving the Problems Hydrogen peroxide according to the present invention
A method and an apparatus for treating wastewater containing wastewater, comprising:
To the extent harmless to biological sludge (microbial sludge) used for
Hydrogen peroxide in wastewater is reduced and rendered harmless by microbial sludge.
And then treat the detoxified water in the biological treatment step.
And the biological sludge that grows in this biological treatment process
Effective use as microbial sludge for the above-mentioned hydrogen peroxide treatment
It is configured so that

The method for treating wastewater containing hydrogen peroxide according to the present invention is characterized in that wastewater containing hydrogen peroxide, at least hydrogen fluoride as an inorganic acid, a BOD component and a nitrogen compound is subjected to a first reaction in a defluorination treatment step. Introduced into the tank, slaked lime was added and mixed to make hydrogen fluoride into calcium fluoride, and then this wastewater was introduced into the second reaction tank, and mineral acid was added and mixed to granulate the calcium fluoride. 1 reaction tank, 2nd
Microbial sludge is added to and mixed in at least one of the reaction tanks to perform a detoxification treatment of hydrogen peroxide, and a polymer flocculant is further added to and mixed with the detoxification treatment liquid from the second reaction tank, and the microbial sludge and the production thereof are mixed. After the particles are subjected to a coagulation treatment, they are introduced into a sedimentation tank and separated into settled sludge and supernatant water.
The components and nitrogen compounds are treated in a biological nitrification and denitrification step, and the biological sludge precipitated and separated in the biological sedimentation tank in this step is used as the microbial sludge for the reduction and detoxification treatment.

[0012] The treatment apparatus for wastewater containing hydrogen peroxide according to the present invention.
The equipment consists of a defluorination treatment device for removing hydrogen fluoride and a peracid
Detoxification equipment for hydrogen hydride, BOD component and nitrogenation
And a biological nitrification denitrifier for the compound
Waste water treatment device, wherein the defluorination treatment device is
A first reaction vessel having a calcium hydroxide supply unit, to have the mineral acid feed portion
A second reaction tank, a coagulation reaction tank, and a precipitation tank are connected in this order.
The biological nitrification and denitrification apparatus is provided with
Components and nitrogen compounds remaining in the supernatant water from the tank
A biological treatment tank for treating
A biological sedimentation tank for separating biological sludge in the treated water,
The biological sludge discharge part of the biological sedimentation tank is the first reaction tank,
Make sure that at least one of the two reactors is
And features.

[0013]

[Action] In the processing method of the hydrogen peroxide-containing wastewater, hydrogen peroxide first reaction vessel and the defluorination process /
Or, it reacts with microorganisms in microbial sludge in the second reaction tank and is reduced and decomposed into water and oxygen. Hydrogen fluoride reacts with slaked lime in the first reaction tank to form fine-particle calcium fluoride, and in the second reaction tank, Granulation of this calcium fluoride proceeds by adjusting the pH with a mineral acid, and furthermore, the addition of a polymer flocculant causes the flocculation reaction of the microbial sludge in the second reaction tank and the above-mentioned granulated product to proceed. It becomes settled sludge in the tank and separated from the supernatant water after defluorination treatment. BOD component and the nitrogen compounds remaining in the supernatant water is treated with the next stage of biological nitrification denitrification step, where grown microorganism organism
The sludge is separated and settled as biological sludge in the sedimentation tank, and at least a part thereof is supplied to the first reaction tank and / or the second reaction tank and used for reductive decomposition of hydrogen peroxide.

[0014] Further , the apparatus for treating the hydrogen peroxide-containing wastewater.
Then, biological sludge (microbial sludge) from the biological sedimentation tank
Peracid in the wastewater supplied to the reaction tank and / or the second reaction tank
Hydrogen hydride reacts with microorganisms in microbial sludge and returns to water and oxygen
Originally decomposed. Slaked lime is in the first reactor and mineral acid is in the first reactor.
Each is supplied to two reaction tanks. And the drainage
Hydrogen hydride reacts with slaked lime to form fine calcium fluoride
In the second reaction tank, the pH was adjusted with mineral acid to
Granulation of calcium chloride proceeds. Furthermore, in the coagulation reaction tank
Is a processing solution from the second reaction tank by adding a polymer flocculant.
Agglomeration reaction of microbial sludge and the above granulated material in
Aggregates become sludge in the sedimentation tank and defluoridation
Separated from the supernatant water. This remains in the supernatant water
BOD component and nitrogen compound are biological nitrification denitrification equipment
The microorganisms grown here are treated in a biological sedimentation tank
Separated as sludge, at least a part of which is
The hydrogen peroxide is supplied to the reaction tank and / or the second reaction tank and
Used for original decomposition.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments shown in the drawings. Example 1 FIG. 1 shows hydrogen peroxide, at least acetic acid as a BOD component,
1 shows an apparatus for treating acidic wastewater containing at least hydrogen fluoride as a nitrogen oxide and an inorganic acid. This apparatus is a new line 46 for processing a conventional waste water 61 containing HF, acetic acid (BOD component) and nitric acid (HNO ₃ ).
(Shown by a bold line in the figure)
₂ O ₂ , HF, annimore (NH ₃ ) and hydrochloric acid (HC
1) is configured so that the new wastewater 62 containing l) can be treated in combination with the above-mentioned conventional wastewater 61. The new wastewater 62 is roughly divided into a raw water tank 21, a de-F process 31, a de-BOD de-N process 41, and a dehydrator 51. Have been.

The above-mentioned F removal step 31 comprises a first reaction tank 32 and a second reaction tank 32.
The reaction tank 33, the third reaction tank 34, and the precipitation tank 35 are connected in this order, and the BOD removal N step 41 is a biological nitrification denitrification step, and is a biological removal N tank 42, a post-aeration tank. 4
3 and the biological sedimentation tank 44 are connected in this order. And the supernatant water outlet of the settling tank 35 is
The sludge outlet is connected to a sludge mixing tank 52, and the sludge outlet of the biological sedimentation tank 44 is connected to a pump 45.
Is connected to a sludge measuring box 47 and the above-mentioned sludge mixing tank 52 via a dehydrator 51. The sludge mixing tank 52 is connected to a raw water tank 21 via a dehydrator 51, and the raw water tank 21 is connected to a first reaction tank 32 via a pump 22. Further, the new line, that is, the sludge supply line 46 is connected to the first reaction tank 32 and the second reaction tank 33, respectively. In the figure, pHC is a pH indicating controller.

In this waste water treatment apparatus, the conventional waste water 61, the new waste water 62, and the dewatered separated water 53 are stirred and mixed in the raw water tank 21 to form a mixed waste water of, for example, H ₂ O ₂ 60 to 1000 ppm, fluorine 1000 ppm, and pH 1 to 3. In the first reaction tank 32, the addition reaction of Ca (OH) ₂ causes the generation reaction of CaF ₂ fine particles from HF (the generation of primary nuclei of CaF ₂ ) in parallel with the pH adjustment to pH 9.
After the completion of the pH adjustment, a part of the sludge 48 returned from the biological sedimentation tank 44 is added to the first reaction tank 32 and mixed, and H ₂ O ₂
Is decomposed into water within an instant or within 5 minutes.

The sludge mixture from the first reaction tank 32 is supplied to the second
In the reaction tank 33, the pH was adjusted to 7 by adding and mixing H ₂ SO _4.
After the granulation of CaF ₂ is carried out for about 30 minutes, the coagulation reaction of sludge and CaF ₂ granules is carried out in the third reaction tank 34 by adding and mixing a polymer flocculant for about 30 minutes. Then, it flows into the sedimentation tank 35 and is separated into the supernatant water 36 and the drawn sludge 37. The supernatant water 36 flows into the BOD removal de-N step 41, and the drawn sludge 37 flows into the sludge mixing tank 52.

In the BOD removal N step 41, the BOD removal
And acetic acid is a component, NH ₃ or the like are removed are nitrogen compounds. The biologically treated water 63 from the biological sedimentation tank 44 is introduced into an activated carbon adsorption device (not shown) to remove residual fluorine (about 5 ppm as F), and a part of the drawn sludge 64 is returned sludge 48 and the remaining part is sludge. The excess sludge 49 is returned, and a part of the returned sludge 48 is returned to the biological denitrification tank 42, and the remainder is supplied to the first reaction tank 32. The excess sludge 49 is mixed with the extracted sludge 37 in the sludge mixing tank 52 and treated by the dehydrator 51 to be separated into the dewatered cake 54 and the dewatered separated water 53. Processing of the components is performed. The dewatered cake 54 is disposed of by incineration or the like as a waste cake.

That is, the above-mentioned BOD removal N step 41
BOD in supernatant water 36 from sedimentation tank 35 in de-F process 31
Nitrogenation of components (CH ₃ COOH etc.) by aerobic bacteria
Compounds (HNO ₃ , NH ₃ etc.) by nitrifying bacteria and denitrifying bacteria
Each of them is removed, and the biological removal N tank 42 and the post-aeration tank 4
The growth microorganisms and microbial sludge in the biological settling tank 44 at 3
Sludge, and a part of the sludge is returned to the biological denitrification tank 42.
48, and the remaining sludge 49.

The sludge from the biological sedimentation tank 44 is supplied to the first
It may be supplied to the second reaction tank 33 instead of the reaction tank 32,
It may be supplied separately to both the first and second reaction tanks. Further, the excess sludge 49 can be directly supplied to the first reaction tank 32 without passing through the sludge mixing tank 52, or, if desired, the sludge mixed liquid or the dewatered cake 54 in the biological removal N tank 42 or the post-aeration tank 43. It is also possible to supply parts and use them for the decomposition of H ₂ O ₂ .

Embodiment 2 FIG. 2 shows that a primary F removal step 71 and a secondary F removal step 81 are directly connected instead of the removal F step 31 in FIG. 1, and the other steps are the same as those in FIG. The same is true. The above-mentioned primary removal F step 7
1 is substantially the same as the de-F step 31, and is composed of a primary reaction tank 72, a secondary reaction tank 73, a primary flocculation tank 74 and a primary precipitation tank 75. A tank 82, a secondary coagulation tank 83, and a secondary precipitation tank 84 are provided.

In this apparatus, H ₂ O ₂ , HF, HNO ₃
And most H ₂ O ₂ and HF in the acid waste water containing CH ₃ COOH is removed by the primary de-F steps. The supernatant water 76 from the primary sedimentation tank 75 is mixed with a part of the returned sludge 48 in the tertiary reaction tank 82 after the inorganic coagulant PAC is added. A part of the returned sludge 48 is added and mixed. As a result, the trace amount of H ₂ O ₂ remaining in the supernatant water 76 is totally reduced and decomposed, and the sludge such as CaF ₂ remaining in the supernatant water 76 and the newly added microbial sludge are subjected to coagulation treatment. This coagulated sludge is separated in the secondary sedimentation tank 84 and the supernatant water 85
Flows into the de-BOD de-N step 41 for biological treatment. In FIG. 2 , reference numerals 77 and 86 denote drawn sludge.

In the present invention, the amount of sludge used for decomposing H ₂ O ₂ is 0.1 kg or more per 1 kg of H ₂ O ₂ in the wastewater, when converted to volatile biological sludge dry weight (MLVSS). Is preferable, and it is possible to decompose the entire amount of H ₂ O ₂ , but it is more preferable to use it in excess. This not only eliminates the possibility of H ₂ O ₂ leakage due to excessive use, but also does not cause any particular disadvantage in the F-removing step or the BOD-removing N-removing step. Because it only increases.

Next, an experimental example of the present invention will be described. Experimental Example In order to understand the H ₂ O ₂ decomposing ability of microbial sludge and its mechanism, the following test was attempted. Sludge used: sludge from biological removal N tank, MLSS 5g
_{/ L MLVSS 3g / l H 2} O 2 reagent: Concentration 30 wt% 0.3 g / ml reagent 1) to six beakers the same sludge by 1l turned 2) all 3 stirred at 60 rpm) H ₂ to each beaker by changing the amount of O ₂ were charged, the residual H ₂ O ₂ for every elapsed time multiplied by the volume after having measured by H ₂ O ₂ test paper, the results of the examination of residual H ₂ O ₂ by weight Table 1 ].

[0026]

[Table 1]

RUN Nos. 1 to 4 show that the MLVSS required to decompose the total amount of H ₂ O ₂ , that is, the weight of organic sludge, is about 1/10 or more of the weight of H ₂ O ₂ . A similar test was performed on urine-based organic sludge, and the result was about 1/10 or more. Also, RUN No.4 ~
According to 6, the excess H ₂ O ₂ was not decomposed thereafter, no matter how much time had passed. This indicates that cells capable of decomposing sludge have been completely killed. The cells remaining capable of decomposing H ₂ O ₂ remain H
Although ₂ O ₂ has foamed be charged, after all cells died completely foaming phenomenon be charged with excess H ₂ O ₂ was observed. This proved that the sludge decomposed H ₂ O ₂ , and erroneously added H to the biological treatment process.
The situation mechanism in the case where ₂ O ₂ was leaked can also be inferred. That is, H ₂ O ₂ completely kills the bacterium, not the dimension of whether or not the bacterium is inhibited. However, if a small amount of H ₂ O ₂ leaks with respect to the total abundance of the bacteria in the biological reaction system, it is only killed by that amount, and it is presumed that the biological treatment function does not reach a lethal state. it can. Next, since the H ₂ O ₂ waste water is usually mixed with other acids and alkalis and is often not neutral, a study was also conducted to determine the appropriate pH for sludge to decompose H ₂ O ₂ . As a result, in extreme acid and alkali atmospheres, sludge impairs its decomposition function before decomposing H ₂ O ₂ ,
H was 6 to 10, and 7 to 8 was optimal, and it was found that microbial sludge was weak to acid and somewhat strong to alkali.

[0028]

As is apparent from the above description, the present invention
In the method for treating such waste water containing hydrogen peroxide ,
Hydrogen peroxide is used for biological treatment of BOD components
Detoxification by microbial sludge to an extent harmless to material sludge
After the treatment, this detoxified water is treated in the biological treatment step.
Biological sludge that grows in this biological treatment process
Is effective as microbial sludge for hydrogen peroxide treatment as described above.
It is intended to be used. Thus, in the present invention,
A process for treating hydrogen oxide and a process for treating biological matter such as BOD components
Are configured to proceed with each other
Therefore, the above wastewater can be treated extremely rationally.
it can.

The hydrogen peroxide-containing wastewater of the present invention
The treatment apparatus includes a first reaction tank having a slaked lime supply unit, and a mineral acid.
A second reaction tank having a supply unit, a coagulation reaction tank, and a precipitation tank;
Are connected in this order to form a defluoridation device,
The biological sludge discharge part of the tongue tank is either the first reaction tank or the second reaction tank.
Because at least one was contacted, the structure was
Extremely simple.

In addition, the production of existing biological nitrification denitrification equipment
The sludge discharge section connects the sludge discharge section to the existing neutralization equipment.
By simply installing a new supply line, this neutralization device can be replaced with H ₂ O
_{(2) The} present invention can function as a disassembly device.
The treatment device for wastewater containing hydrogen peroxide according to
It can be configured by simple modification.

As described above, according to the present invention, a simple operation
H ₂ O ₂ , HF,
From acidic wastewater containing BOD components and nitrogen compounds,
It is possible to comprehensively remove these water pollutants
Provided is a method and apparatus for treating wastewater containing hydrogen peroxide.
Can be.

[Brief description of the drawings]

FIG. 5 is a flowchart illustrating an embodiment of the present invention.
You.

FIG. 2 9 is a flowchart illustrating another embodiment.

[Explanation of symbols]

 Reference Signs List 21 raw water tank 22 pump 31 de-F step 32 first reaction tank 33 second reaction tank 34 third reaction tank 35 precipitation tank 36 supernatant water 37 drawn sludge 41 de-BOD de-N step 42 biological de-N tank 43 post-aeration tank 44 organism Settling tank 45 Pump 46 New line (sludge supply line) 47 Measuring box 48 Return sludge 49 Excess sludge 51 Dehydrator 52 Sludge mixing tank 53 Dewatered separated water 54 Dewatered cake 61 Conventional wastewater 62 New wastewater 63 Biologically treated water 64 Pull-out sludge 71 Primary F-elimination step 72 Primary reaction tank 73 Secondary reaction tank 74 Primary coagulation tank 75 Primary sedimentation tank 76 Supernatant water 77 Extraction sludge 81 Secondary de-flation step 82 Tertiary reaction tank 83 Secondary coagulation tank 84 Secondary sedimentation tank 85 Supernatant water 86 Drawn sludge

Continued on the front page (72) Inventor Sakae Ishii 150 Ohira, Odakura, Nishigo-mura, Nishishirakawa-gun, Fukushima Prefecture Shirakawa Works, Shin-Etsu Semiconductor Co., Ltd. −32519 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 3/00-3/34 C02F 1/58 C02F 9/00

Claims (2)

(57) [Claims] 1. A wastewater containing hydrogen peroxide, at least hydrogen fluoride as an inorganic acid, a BOD component and a nitrogen compound is introduced into a first reaction tank in a defluorination treatment step, and slaked lime is added and mixed. Hydrogen is converted into calcium fluoride, and then the wastewater is introduced into a second reaction tank, and mineral acid is added and mixed to granulate the calcium fluoride. At least one of the first reaction tank and the second reaction tank is used. Microbial sludge is added and mixed to reduce hydrogen peroxide for detoxification.
A polymer flocculant was added to the detoxification treatment liquid from the reaction tank and mixed, and the microbial sludge and the granulated product were subjected to a flocculation treatment, and then introduced into a precipitation tank to be separated into precipitated sludge and supernatant water. organisms of BOD component and the nitrogen compounds is treated with biological nitrification denitrification step, which is precipitated separated in the biological settling tank of this step
A method for treating hydrogen peroxide-containing wastewater, wherein the sludge is used as the microbial sludge for the reduction detoxification treatment. 2. A defluorination treatment apparatus for removing hydrogen fluoride.
And hydrogen peroxide reduction detoxification equipment, BOD components and
Biological nitrification and denitrification equipment for nitrogen and nitrogen compounds in this order.
A wastewater treatment device, which is disposed and provided, wherein the defluoridation treatment is performed.
The treatment device includes a first reaction tank having a slaked lime supply unit, and a mineral acid supply unit.
The second reaction tank having a section, the coagulation reaction tank, and the precipitation tank
The biological nitrification denitrification apparatus is connected in the order of
BOD components remaining in the supernatant water from the settling tank; and
A biological treatment tank for treating a nitrogen compound; and
A biological sedimentation tank that separates biological sludge from the treated water of
The biological sludge discharge part of the biological sedimentation tank is the first reaction tank,
Connected to at least one of the second reaction tanks
An apparatus for treating wastewater containing hydrogen peroxide, comprising: