JP2000218283A - Treatment of acidic organic waste water and treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient treating method of acidic org. waste water which does not use a strongly basic chemical high in danger and instruments bringing about complicated administration and also to provide a treating device of the acidic org. waste water which is appropriately used at the time of treating the acidic org. waste water by this treating method. SOLUTION: In the treating method of the acidic org. waste water, the org. matter is decomposed by an organism after adjusting the pH of the acidic org. waste water by subjecting the acidic org. waste water and calcium carbonate 2 to neutralization reaction. The treating device of the acidic org. waste water is provided with a pH adjusting tank 3 for executing the pH adjustment of the acidic org. waste water and a biological treating tank 1, and the pH adjusting tank 3 has a constitution in which granular calcium carbonate 2 is stored and the supplied acidic org. waste water is allowed to overflow, and the biological treating tank 1 is a device for treating the acidic org. waste water, that the acidic org. waste water allowed to overflow from the pH adjusting tank 3 is introduced thereinto and the org. matter in acidic org. waste water is decomposed by the organism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating acidic organic wastewater such as garbage and dried sludge of biological sludge, and more particularly to an acidic organic wastewater utilizing the ability of organisms such as microorganisms to decompose organic substances. The present invention relates to a method and an apparatus for treating wastewater.

[0002]

2. Description of the Related Art Hitherto, a biological treatment method such as an activated sludge method is known as a method for treating acidic organic wastewater such as garbage and dried condensed water of biological sludge. In the biological treatment method, in order to utilize the ability of an organism such as a microorganism to decompose an organic substance, it is necessary to adjust conditions such as temperature, pH, and oxygen concentration in a liquid to a range where the organism can sufficiently operate. In particular, p
As for H, most organisms have an optimal range near neutrality. For this reason, when treating acidic organic wastewater using living organisms, it is necessary to adjust the pH to near neutrality in advance.

In order to adjust the pH of acidic organic wastewater, a strong basic agent such as sodium hydroxide or calcium hydroxide is generally used. To adjust the pH of the acidic organic wastewater using the strong basic agent, a biological treatment tank for decomposing organic substances into microorganisms, or a pH for adjusting the pH of the acidic organic wastewater supplied to the biological treatment tank The method is carried out by supplying an aqueous solution of the strongly basic drug into the adjustment tank using a pump linked to a pH controller and stirring the solution with a stirrer or the like.

[0004]

However, in this method, since a highly dangerous strong basic drug is used, handling of the strong basic drug when adjusting the pH is troublesome. To adjust the pH using a strongly basic drug, a chemical tank, a chemical supply pump, a pH meter,
It was necessary to control the pH using equipment such as an H controller and a stirrer. In addition, in order to accurately control the pH, the electrodes of the pH meter must be periodically calibrated, and the devices must be managed, which is complicated. The present invention has been made in view of the above circumstances, solves the above problems, a highly dangerous strong basic drug, and a simple method for treating acidic organic wastewater without using equipment with complicated management. The task is to provide. It is another object of the present invention to provide an acidic organic wastewater treatment apparatus suitably used when treating acidic organic wastewater by the treatment method.

[0005]

The object of the present invention is to adjust the pH of the acidic organic wastewater by neutralizing the acidic organic wastewater with calcium carbonate, and then decompose organic substances by living organisms. It can be solved by the treatment method of acidic organic wastewater. Further, the problem can be solved by a method for treating acidic organic wastewater, wherein organic matter is decomposed by living organisms while the pH of the acidic organic wastewater is adjusted by neutralizing the acidic organic wastewater with calcium carbonate.

[0006] Further, the above-mentioned problem is a problem of pH of acidic organic wastewater.
An acidic organic wastewater treatment device having a pH adjustment tank for performing adjustment and a biological treatment tank, wherein the pH adjustment tank can contain granular calcium carbonate, and the supplied acidic organic wastewater is supplied to the pH adjustment tank. Is overflowed after neutralization in the biological treatment tank.
Organic wastewater overflowing from the H adjustment tank is introduced,
The problem can be solved by a treatment apparatus for acidic organic wastewater, wherein organic matter in the acidic organic wastewater is decomposed by living organisms.

Further, the pH for adjusting the pH of acidic organic wastewater is adjusted.
An acidic organic wastewater treatment device having an adjustment tank and a biological treatment tank, wherein the pH adjustment tank can accommodate granular calcium carbonate and has pores smaller than the particle size of the calcium carbonate, In the biological treatment tank, the organic wastewater after the neutralization treatment flowing out of the holes is introduced, and the organic wastewater in the acidic organic wastewater is decomposed by living organisms. Good. In the present invention, “pores smaller than the particle size of calcium carbonate” refers to holes smaller than the particle size of granular calcium carbonate when charged into a pH adjusting tank.

Further, the present invention is an acidic organic wastewater treatment apparatus comprising a pH adjusting tank for adjusting the pH of acidic organic wastewater and a biological treatment tank for decomposing organic substances of the acidic organic wastewater by living organisms. , Provided in the biological treatment tank, can accommodate granular calcium carbonate,
It has pores smaller than the particle size of the calcium carbonate, and the acidic organic wastewater in the pH adjusting tank and the acidic organic wastewater in the biological treatment tank can be mutually circulated through the holes. It is good also as an acidic organic wastewater treatment apparatus characterized by the above.

[0009]

FIG. 1 is a diagram showing an example of an apparatus for treating acidic organic wastewater of the present invention. In FIG. 1, reference numeral 3 denotes a pH adjusting tank for adjusting the pH of acidic organic wastewater, and reference numeral 1 denotes a biological treatment tank for decomposing organic substances of acidic organic wastewater by living organisms. The pH adjustment tank 3 comprises:
It is provided on the inner wall of the biological treatment tank 1 and contains granular calcium carbonate 2.

In order to treat acidic organic wastewater using this apparatus, first, acidic organic wastewater is continuously supplied to the pH adjusting tank 3 as shown by an arrow 7 in FIG. After the pH of the acidic organic wastewater is adjusted by the summation reaction, the wastewater is allowed to overflow from the opening 3a of the pH adjusting tank 3 as shown by an arrow 8 in FIG. Then, pH adjustment tank 3
The organic wastewater overflowed from is supplied to the biological treatment tank 1. At this time, the liquid level 6 in the biological treatment tank 1
It is set to be at a position lower than the opening 3a of the pH adjusting tank 3. Then, the organic matter (BOD component) in the organic wastewater supplied to the biological treatment tank 1 is decomposed by living organisms, and the organic matter (BOD component) in the biological treatment tank 1 is discharged from an outlet 5 provided at the upper part of the wall facing the pH adjusting tank 3 in FIG. By discharging as shown by the arrow 9, treated water is obtained.

In the pH adjusting tank 3, a neutralization reaction between the acidic organic wastewater and the calcium carbonate 2 is performed. By this neutralization reaction, the pH of the acidic organic wastewater is adjusted to almost neutral. In the neutralization reaction of the acidic organic wastewater, as shown in the following reaction formula (I), the calcium carbonate 2 put in the pH adjusting tank 3 is dissolved by contact with the acidic organic wastewater to dissolve the carbonate ion and the calcium ion. The reaction is carried out by reacting the carbonate ion with the hydrogen ion exhibiting the acidity of the acidic organic wastewater.

[0012]

Embedded image

The calcium carbonate 2 is supplied in the form of granules having a size that does not flow out at least by overflow of the acidic organic wastewater. The introduced calcium carbonate 2 is consumed by performing a neutralization reaction with acidic organic wastewater while being held in the pH adjustment tank 3. The calcium carbonate whose particle size has been reduced by this consumption finally flows out into the biological treatment tank 1 by overflow together with the acidic organic wastewater. The granular calcium carbonate 2 consumed in this way is p
It is periodically refilled in the H adjustment tank 3.

The organic matter (BOD component) in the organic wastewater overflowed from the pH adjusting tank 3 is decomposed by living organisms. Microorganisms, activated sludge, biofilm, and the like attached to the antibody, such as sponge and granules, can be used as the organism here. In particular, microorganisms attached to the antibody are preferably used. It is preferable that the living thing is held in the biological treatment tank 1 in advance. The decomposition of organic matter by living organisms is preferably performed while the inside of the biological treatment tank 1 is aerated with air sent out from the air diffuser 4 in order to stir the inside of the biological treatment tank 1 and adjust the oxygen concentration in the liquid. Furthermore, the temperature in the biological treatment tank 1 and the organic matter (B
It is desirable to adjust the conditions such as the concentration of the OD component) and the amount of the organism to a range where the organism can effectively decompose organic substances.

According to such a method for treating acidic organic wastewater, the pH of the acidic organic wastewater is adjusted by neutralizing the acidic organic wastewater with calcium carbonate 2. Therefore, the acidic organic wastewater can be used without using a strong basic agent. The pH of the organic wastewater can be adjusted. Since the neutralization reaction is based on a dissolution reaction by contact with calcium carbonate, the pH is kept constant by the solubility of the calcium carbonate. Therefore, it is not necessary to use devices with complicated management to control the pH. In addition, since calcium carbonate 2 is highly safe,
It is easier to handle as compared with highly dangerous highly basic drugs, and can safely treat acidic organic wastewater. Furthermore, since calcium carbonate 2 has a very low solubility,
It is not consumed in a short time, the frequency of replenishment is low, and no labor is required.

In the above-mentioned apparatus for treating acidic organic wastewater, the pH adjusting tank contains at least granular calcium carbonate 2 having a size not to flow out due to overflow of the acidic organic wastewater. Since the organic wastewater overflows after the neutralization treatment, the calcium carbonate 2 and the acidic organic wastewater can be neutralized in the pH adjustment tank 3 and almost neutralized in the pH adjustment tank 3. The adjusted acidic organic wastewater can be supplied to the biological treatment tank 1. Further, by introducing granular calcium carbonate 2 into the pH adjusting tank 3,
Calcium carbonate 2 to be neutralized with acidic organic wastewater can be easily supplied.

As described above, the acidic organic wastewater treatment apparatus of the present invention can be supplied from the pH adjustment tank 3 to the biological treatment tank 1 by overflowing, as shown in FIG. A hole 3c smaller than the granular calcium carbonate 2 is provided in the bottom surface 3b of the pH adjustment tank 3 so that the liquid level 6 in the biological treatment tank 1 is lower than the bottom surface 3b of the pH adjustment tank 3. Organic wastewater may be supplied from the pH adjustment tank 3 to the biological treatment tank 1 through the hole 3c. In this case, the number of holes 3c may be plural as shown in FIG. 2, or may be one. Hole 3
c is the granular calcium carbonate 2 when charged into the pH adjusting tank 3.
What is necessary is just to be formed smaller.

In the apparatus for treating acidic organic wastewater shown in FIG. 2, the liquid level 6 in the biological treatment tank 1 is
May be set at a position higher than the bottom surface 3b, and the wastewater may be allowed to flow between the pH adjustment tank 3 and the biological treatment tank 1 through the hole. In this case, the untreated acidic organic wastewater can be supplied to one or both of the pH adjustment tank 3 and the biological treatment tank 1. In addition, pH adjustment tank 3
The circulation of wastewater between the inside and the biological treatment tank 1 is promoted by aerating the inside of the biological treatment tank 1 with air sent out from the air diffuser 4.

[0019]

The present invention will be described below in more detail with reference to examples and comparative examples.

Example 1 The treatment of acidic organic wastewater was carried out using the biological treatment apparatus shown in FIG. That is, acidic organic wastewater having the properties shown in Table 1 was introduced into a pH adjusting tank 3 having a volume of 0.05 l and charged with 1.0 g of granular calcium carbonate having a particle diameter of about 5 mm or more at a flow rate of 0.2 l / hr. After continuously adjusting the pH of the acidic organic wastewater, the pH is adjusted.
It overflowed from the opening 3a of the adjustment tank 3. Then, the effective volume of the organic wastewater overflowed from the pH adjusting tank 3 into which 0.64 l of the microorganism-adhering carrier is introduced is set so that the liquid level 6 is lower than the opening 3 a of the pH adjusting tank 3. The organic matter (BOD component) was decomposed while being supplied to a 2 l biological treatment tank 1 and aerated at an air flow rate of 100 l / hr to obtain treated water.

[0020]

[Table 1]

[0021]

Embodiment 2 As shown in FIG. 2, five 3c holes having a diameter of 3 mm are provided on the bottom surface 3b of the pH adjusting tank 3 of the biological treatment apparatus 1 used in Example 1, and the liquid level in the biological treatment apparatus 1 is increased. 6 is a position higher than the bottom surface 3b in the pH adjustment tank 3, a biological treatment apparatus that allows wastewater to flow between the pH adjustment tank 3 and the biological treatment tank 1 through the hole 3c. To treat acidic organic wastewater. That is, the same acidic organic wastewater as in Example 1 is continuously supplied to the biological treatment tank 1 at the same flow rate as in Example 1, and the liquid level 6 is at a position slightly higher than the bottom surface 3b of the pH adjustment tank 3. And adjusting tank 3
While adjusting the pH of the acidic organic wastewater in the same manner as in Example 1, the organic matter (BOD component) was decomposed in the biological treatment tank 1 in the same manner as in Example 1 to obtain treated water.

[0022]

Comparative Example The treatment of acidic organic wastewater was performed using the biological treatment tank 1 similar to the biological treatment apparatus used in Example 1. That is, the same acidic organic wastewater as in Example 1 is continuously supplied to the biological treatment tank 1 at the same flow rate as in Example 1, and the organic matter ( BOD component) was decomposed to obtain treated water.

[0023]

Prior Art The same acidic organic waste water as in Example 1 was neutralized to pH 6.8 with 0.1N NaOH in advance, and treated water was obtained in the same manner as in Comparative Example. Table 2 shows the results.

[0024]

[Table 2]

From Table 2, the treated water obtained in Example 1 was
pH 6.8, BOD 450 mg / l, treated water obtained in Example 2 was pH 7.3, BOD 450 mg / l
It was confirmed that the BOD was lower than that of the treated water obtained in the comparative example in which the pH was not adjusted. Further, it became clear that treated water having the same pH and BOD as that of the conventional example in which acidic organic wastewater was neutralized with 0.1N NaOH in advance was obtained. Furthermore, the BOD of the treated water obtained in Example 1 and Example 2 was equal to or lower than the reference value (600 mg / l) for discharging to the sewer, and the pH was within the reference value for discharging the sewer (5 to 9). .

[0026]

As described above, in the method for treating acidic organic wastewater of the present invention, the pH of the acidic organic wastewater is adjusted by neutralizing the acidic organic wastewater with calcium carbonate. The pH of the acidic organic wastewater can be adjusted without using any. Therefore, it is not necessary to use devices with complicated management to control the pH. As a result, acidic organic wastewater can be treated with a simpler device than before. In addition, calcium carbonate is highly safe, so it is easier to handle as compared with highly dangerous strong basic drugs, and can treat acidic organic wastewater safely. Further, since calcium carbonate has a very low solubility, it is not consumed in a short time, the frequency of replenishment is low, and no labor is required.

In the above-mentioned apparatus for treating acidic organic wastewater, since the pH adjusting tank contains granular calcium carbonate, the calcium carbonate and the acidic organic wastewater are neutralized in the pH adjusting tank. Can be done. further,
By feeding granular calcium carbonate into the pH adjusting tank, calcium carbonate to be neutralized with acidic organic wastewater can be easily supplied.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an apparatus for treating acidic organic wastewater of the present invention.

FIG. 2 is a view showing another example of the acidic organic wastewater treatment apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Biological treatment tank 2 Calcium carbonate 3 pH adjustment tank 3a Opening 3b Bottom surface 3c Hole 4 Air diffuser 5 Outlet 6 Liquid level

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 3/12 C02F 3/12 N

Claims (5)

[Claims] 1. A method for treating acidic organic wastewater, comprising the steps of: adjusting the pH of the acidic organic wastewater by neutralizing the acidic organic wastewater with calcium carbonate; and then decomposing organic substances by living organisms. 2. A method for treating acidic organic wastewater, wherein organic matter is decomposed by living organisms while the pH of the acidic organic wastewater is adjusted by neutralizing the acidic organic wastewater with calcium carbonate. 3. An acidic organic wastewater treatment apparatus having a pH adjusting tank for adjusting the pH of an acidic organic wastewater and a biological treatment tank, wherein the pH adjusting tank is capable of containing granular calcium carbonate and being supplied. The acidic organic wastewater is configured to overflow after the neutralization reaction, and the biological treatment tank is configured to receive the organic wastewater overflowed from the pH adjustment tank and decompose organic substances in the acidic organic wastewater by living organisms. An acidic organic wastewater treatment apparatus, characterized in that: 4. A treatment apparatus for an acidic organic wastewater having a pH adjusting tank for adjusting the pH of an acidic organic wastewater and a biological treatment tank, wherein the pH adjusting tank can contain granular calcium carbonate, and The biological treatment tank has pores smaller than the particle diameter of calcium, and the biological treatment tank is configured to receive the organic wastewater neutralized and flowing out of the pores and decompose organic substances in the acidic organic wastewater by living organisms. A device for treating acidic organic wastewater. 5. An acidic organic wastewater treatment device comprising: a pH adjusting tank for adjusting the pH of acidic organic wastewater; and a biological treatment tank for decomposing organic substances of the acidic organic wastewater by living organisms. It is provided in the biological treatment tank, and can accommodate granular calcium carbonate, and has pores smaller than the particle size of the calcium carbonate, and the supplied acidic organic wastewater is contained in the pH adjustment tank and the An acidic organic wastewater treatment apparatus, wherein a neutralization treatment and a biological treatment are performed at the same time by being able to flow through the inside of the biological treatment tank through the holes.