JPH03285676A - Flocculant-producing new microorganism and treatment of waste water - Google Patents

Abstract

PURPOSE:To enable efficient separation of activated sludge without causing bulking phenomenon by using a microbe-produced flocculant composed mainly of a cultured product of a flocculant-producing microorganism belonging to genus Pseudomonas, etc. CONSTITUTION:The objective flocculant-producing microorganism is selected from Pseudomonas fluorescens KYM-1 strain (FERM P-11333), Pseudomonas cepacia KYM-2 strain (FERM P-11334) (strains belonging to genus Pseudomonas), KYM-3 strain (FERM P-11335) belonging to genus Acinetogacter, etc. A microbe- produced flocculant composed mainly of a cultured product of microorganisms containing at least one of the above strains or its treated product is used in the waste-water flocculation treatment process using activated sludge. The flocculant is effective in suppressing the generation and proliferation of mold which is a main cause of the bulking phenomenon in the separation region of the activated sludge and the treated water. The flocculation effect can be further improved by adjusting the pH to 7-9 in the separation region. An excellent waste-water treating effect can be attained by this process.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a new flocculant-producing microorganism and a wastewater flocculation treatment method, and more specifically, to a wastewater flocculation treatment method using an activated sludge method or the like using a novel flocculant-producing microorganism. The present invention relates to a wastewater coagulation treatment method that prevents bulking of activated sludge and efficiently separates activated sludge from treated water.

(Prior Art and its Problems) Conventionally, activated sludge systems have been widely used as a method for treating wastewater containing various organic substances. This activated sludge method is a highly efficient treatment method and is the most widely used treatment method because it can economically obtain high-quality treated water.

The most important problem remaining in the above activated sludge method is:
After treatment, the treated water and activated sludge are separated, and it is desirable that the activated sludge quickly settles and separates the treated water and activated sludge in the separation area, which is a settling tank. A bulking phenomenon and a differential lock phenomenon occur due to the generation of sludge, and the flocculation effect of the activated sludge is reduced, and the sedimentation and separation of the activated sludge becomes insufficient, resulting in the problem of activated sludge flowing out.

The use of polymeric flocculants such as cationic polymers and inorganic flocculants such as polyvalent metal ions is known as a method of promoting the separation of activated sludge and treated water, but these flocculants cannot be biodegraded. Due to insufficient properties, water is discharged together with treated water, leading to environmental pollution problems.

Therefore, an object of the present invention is to provide a new flocculant-producing microorganism and a wastewater flocculation treatment method that can efficiently separate activated sludge without causing the activated sludge bulking phenomenon in the wastewater flocculation treatment method.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention is directed to the use of Pseudomonas, Acinetobacter
A flocculant-producing microorganism characterized by containing at least one genus selected from the group consisting of the genus Agrobacterium, the genus Enterobacter, the genus Aureobacterium, and the genus Oerscobia, a culture of the above microorganism, or a culture treatment. A microorganism-produced flocculant whose main component is a microbial coagulant, a wastewater coagulation treatment method characterized by bringing the microorganism or microbial-produced flocculant into contact with suspended matter-containing wastewater, and a wastewater coagulation treatment method using an activated sludge method. This wastewater flocculation treatment method is characterized in that microorganisms or microorganism-produced flocculants are present in the treatment system to prevent bulking of activated sludge in a region where activated sludge and treated water are separated.

(For use) In a wastewater flocculation treatment method using activated sludge, the generation of filamentous bacteria, which is the main cause of the bulking phenomenon, can be suppressed by using new bacteria or flocculants produced by these bacteria as flocculant-producing bacteria. This makes the separation of activated sludge and treated water more efficient. In a further preferred embodiment, the separation region p
, H within a specific range, separation of activated sludge and treated water is significantly promoted.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The present inventor cultivated a large number of known flocculant-producing bacteria, Rhodococcus erythropores, in a fructose medium, and in the process of measuring the flocculation effect (power value), found that the titer was 2.
It has been found that there are culture solutions in which the increase is more than double. This culture solution contained several types of bacteria, and when these bacteria were separated, they discovered one that showed particularly high titer.

The flocculant-producing bacteria of the present invention have a flocculant-producing ability that belongs to at least one genus selected from the group consisting of the genus Pseudomonas, the genus Acinetobacter, the genus Agrobacterium, the genus Enterobacter, the genus Aureobacterium, and the genus Oerscobia. It is a bacterium that has the
Erythropores KR-256-2, FERM-PNo,
3923 and Rhodococcus erythropores KR-3
It belongs to a different genus from 1, FERM-P No. 3530, etc., and its agglutination ability is 2 to 3 times or more than those of these known bacteria. Among these genera, Pseudomonas spp.
In the present invention, a group of microorganisms including one genus selected from the group consisting of Acinetobacterium, Acrobatherium, Enterobacter, Aureobacterium, and Oelscobia is referred to as R-3 in the present invention. FERM P-113331 has already been published.
, No. 1]-3334 FERM P-11334)
, same No. 11335 (FERMP-11335), same No. 11336 (FERM P-11336), same No. 11
No. 337 (FERM P-1, 1337), FERM No. 113
57 (FERM P-11357) and FERM P-1135
No. 8 (FERM P1135g).

The above flocculant-producing novel microorganism has the following mycological properties.

(Left below) The mycological properties shown in Table 1 above are described in Bergey's Manual Systematic Bactiology Volume 1.2, which is a bacterial identification book.
of Systematic Bacteriology
y Volume 1゜2), (1984), the KYM-1 strain is consistent with Pseudomonas fluorescens described on page 165 of the same book, and KYM-1
The strain was identified as Pseudomonas fluorescens and was published in FERM P-11,3331.
It has been deposited as.

It is reasonable to consider that the KY'+'-2 strain is Pseudomonas cepacia described on page 175 of the same book,
No. 34 (FERM P-11334).

The KYM-3 strain corresponds to the Acinetobacter genus bacteria described on page 303 of the same book, and was published in FIKEN Bacteria No. 11335 (FEBM).
P-11335).

Although the description of the KYM-4 strain is almost identical to Agrobacterium leideobacter described on page 254 of the same book, there are slight differences in details such as sugar assimilation ability, so taxonomically it is best to consider it as a close relative of the same species. It is appropriate, and the main field is the 11th
No. 336 (FERM P11336).

The KYM-5 strain is completely identical at the genus level to the Enterobacter bacteria described on page 465 of the same book, and is
No. 7 (FERM P-11337).

The KYM-6 strain corresponds to the Aureobacterium genus bacteria described on page 1323 of the same book, and the KYM-7 strain corresponds to the Oerscobia genus bacteria described on page 1489 of the same book at the genus level.

The KYM-6 strain was published in FER No. 11.357 (FER
M P-11357) and KYM-7 strains have been deposited as FERM P-11358 (FERM P-11358).

The flocculant of the present invention is mainly composed of a culture or cultured product of a microorganism containing at least one of the above genus,
It may be in any form such as the culture solution itself, its concentrate, its filtrate, its filtration residue, or its dried product.

1 2 Furthermore, the flocculating ability of the flocculant can be further improved by containing one or more cationic inorganic salts such as calcium ions, or by incorporating them at the time of use.

The feature of the wastewater coagulation treatment method of the present invention is that it uses a small number of the above-mentioned coagulant-producing bacteria (at least one kind), and the wastewater to be applied may be any wastewater containing suspended matter, but particularly active In a wastewater flocculation treatment method using sludge, the generation and proliferation of filamentous bacteria, which is the main cause of bulking, can be suppressed in the separation area between activated sludge and treated water.Therefore, the present invention can suppress the generation and proliferation of filamentous bacteria, which are the main cause of bulking. It is particularly effective in treating wastewater.

Wastewater coagulation treatment methods using activated sludge methods using microorganisms are well known, and the present invention is applicable to any of these well-known wastewater coagulation treatment methods, and is not particularly limited.

In a preferred embodiment of the present invention, even better force values are obtained by setting the pH in the separation zone where activated sludge and treated water are to be separated to be in the range of 7 to 9, particularly preferably 8.0 to 8.5. It will be done.

In the present invention, the amount of flocculant-producing bacteria added is 0 as the culture solution.
．． The content is 5% by weight or more, preferably 0.5 to 10% by weight. Even when the concentration of flocculant-producing bacteria was added in excess of 10%, the strength value did not improve in accordance with the amount added.

(Example) Culture solutions of the conventionally known Rhodococcus erythropores and the flocculant-producing bacteria of the present invention were cultured in the following liquid medium for 30 minutes.
Culture was performed at 0'C with shaking.

The R-1 bacterium is the conventionally known Rhodococcus erythropores, and the R-3 bacterium of the present invention is the KYM1 strain (FERM
P-11333), KYM-2 strain (FERM P-1
1334), K Y M-3 strain (FERM P-11
335), KYM4 strain (FERM P-11336),
KYM-5 strain (FERM P-11337), KYM-
6 strains (FERM P-11357) and KYIII-7
strain (FERM P-11358).

Liquid Seiko concave dish reduced carbon source 10 g/QK, HP
O4' 5 g/ρKH2PO,2g/
f2 MgSO, 0.2g/Flood (NH4)2S0. 0. 5
g#2 yeast extract 0.5g/ρNa
Cl 0. 1 g/ff(
1) Titer (a) Test solution Using fructose as the carbon source of the liquid medium, p
A culture solution obtained by culturing with shaking for 5 days in a medium whose H value was adjusted to 8.5 was used as a test solution. The temperature was 30'C.

(b) Force value evaluation method: 5000 mg of kaolin in a 100 mA graduated cylinder.
/ρ solution at 80mβ, added inorganic kaolin and culture solution in predetermined amounts, gently stirred by inverting, and then added 0.5N NaOH.
The pH was adjusted to pH 7.0 with and HCI. Adjust the total volume to 100rr+j2 with distilled water, stir again by turning over, and let stand for 5 minutes.
OD of supernatant water after 5 minutes. . was measured, and the agglutination titer was expressed as 1/Dsso.

The oral changes in agglutination titer of R-1 bacteria and R-3 bacteria were as shown in Figure 1.

As described above, the bacterium R-3 of the present invention exhibits significantly superior titer compared to other bacteria. In addition, R-1 is a conventionally known Rhodococcus erythropores bacterium.

(2) pH during aggregation The pH during aggregation was adjusted to 5 to 10, and the optimum aggregation pH was studied.

As the pH increases from 5 to 8 as shown in the second diagram, 0D5
It was revealed that 0D55o decreased and 0D55o increased at pH higher than that, and the optimal aggregation i)H of the culture solution was 8.0 to 8.5.

(Effect) As explained above, the flocculant-producing bacteria of the present invention was newly discovered to have flocculant-producing ability, and compared to conventional flocculant-producing bacteria, it has particularly high R-3 A group of microorganisms containing at least one genus selected from the group consisting of the genus Pseudomonas, Acinetobacter, Agrobacterium, Enterobacter, Aureobacterium, and Copia is extremely superior. It has flocculant production ability.

Therefore, according to the method of the present invention, excellent wastewater treatment effects can be obtained.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between agglutination titer and elapsed days;
FIG. 2 is a diagram showing the relationship between agglutination titer and pH.

Claims (8)

[Claims] (1) A flocculant-producing microorganism comprising at least one genus selected from the group consisting of Pseudomonas, Acinetobacter, Agrobacterium, Enterobacter, Aureobacterium, and Oelscobia. (2) Pseudomonas genus is Pseudomonas fluorescens KYM-1 strain (FERM P-11333) or Pseudomonas cepacia KYM-2 strain (FERM P-
11334), the genus Acinetobacter is Acinetobacter KYM-3 strain (FERM P-11335), and the genus Agrocterium is Agrobacterium KYM-3.
4 strains (FERM P-11336), and the Enterobacter genus is Enterobacter KYM-5 strain (FERM P-11336).
P-11337), and the genus Aureobacterium is Aureobacterium KYM-6 strain (FERM P-11
357), and the genus Oerscobia is Oerscobia K.
The flocculant-producing microorganism according to claim (1), which is YM-7 strain (FERM P-11358). (3) A microorganism-produced flocculant whose main component is a culture or cultured product of the microorganism according to claim (1) or (2). (4) Claim (1) containing one or more cationic inorganic salts
) or the microorganism-produced flocculant according to (2). (5) A wastewater flocculation treatment method, which comprises bringing the microorganism or microorganism-produced flocculant according to claims (1) to (4) into contact with suspended matter-containing wastewater. (6) In a wastewater coagulation treatment method using an activated sludge method,
A wastewater flocculation characterized in that the microorganism or microorganism-produced flocculant according to claims (1) to (4) is present in a treatment system to prevent bulking of activated sludge in a separation area between activated sludge and treated water. Processing method. (7) The wastewater coagulation treatment method according to claim (6), wherein the pH of the activated sludge separation region is maintained at 7 to 9. (8) The wastewater coagulation treatment method according to claim (7), wherein the wastewater to be treated is wastewater that is likely to generate filamentous bacteria.