JPH07108216B2 - Microorganism-produced flocculant and wastewater flocculation method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbial-produced flocculant and a wastewater flocculation treatment method, and more specifically, in a wastewater flocculation treatment method such as an activated sludge method, a novel microbial-produced flocculant is used to prevent bulking of activated sludge. The present invention relates to a wastewater coagulation treatment method for efficiently separating activated sludge from treated water.

[0002]

2. Description of the Related Art Conventionally, an activated sludge system has been widely used as a method for treating wastewater containing various organic substances. This activated sludge system is a highly efficient treatment method, and is the most widely used treatment method because it produces high quality treated water economically.

The most important problem remaining in the activated sludge system is the separation of the treated water and the activated sludge after treatment, and the treated water and the activated sludge are rapidly separated in the separation area which is a settling tank. It is desirable to separate by sedimentation,
In the separation area, a bulking phenomenon or a deflocculation phenomenon occurs due to the generation of filamentous fungi or the like when standing still, and the flocculating floc action of the activated sludge is reduced, and the sedimentation and separation of the activated sludge becomes insufficient, causing a problem of the activated sludge outflow.

As a method for promoting the separation of activated sludge and treated water, a method of using a polymer flocculant such as a cationic polymer or an inorganic flocculant such as a polyvalent metal ion is known. These flocculants are known. Since its biodegradability is insufficient, the problem of environmental pollution is caused by being discharged together with the treated water. Therefore, an object of the present invention is to provide a microbial-produced flocculant and a effluent flocculation method capable of efficiently separating activated sludge without causing the bulking phenomenon of activated sludge in the effluent flocculation treatment method.

[0005]

The above object can be achieved by the present invention described below. That is, the present invention relates to Pseudomonas fluorescens KYM-1 strain (FERM).
P-11333) or Pseudomonas cepacia KYM-2 strain (FERM P-11334), Acinetobacter genus, Agrobacterium genus Agrobacterium KYM-4 strain (FERM P-113
36), containing as a main component a culture or a culture-treated product of a flocculant-producing microorganism characterized by containing at least one genus or one genus selected from the group consisting of Enterobacter, Aureobacteria and Oerscovia. Microorganism producing flocculant, in the wastewater flocculating treatment method characterized by contacting the microorganism producing flocculant with the suspension-containing wastewater, and the wastewater flocculating treatment method by the activated sludge method, the microorganism producing flocculant is present in the treatment system In the separation area of activated sludge and treated water, the activated sludge is prevented from bulking.

[0006]

[Function] In a wastewater coagulation treatment method using activated sludge,
By using a flocculant produced by a new bacterium as a flocculant-producing bacterium, the generation of filamentous fungi, which is the main cause of the bulking phenomenon, is suppressed, and the separation of activated sludge and treated water becomes efficient. In a further preferred embodiment, the isolation region p
By setting H to a specific range, the separation of activated sludge and treated water is significantly promoted.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. The present inventor cultivates a large number of known flocculant-producing bacteria Rhodococcus erythropoles in a fructose medium, and in the process of measuring the flocculating effect (potency value), a culture in which the titer increases more than twice as much as usual. It was found that liquid was present. Several kinds of bacteria were mixed in this culture solution, and when these bacteria were separated, a bacteria showing a particularly excellent titer was found.

The above flocculant-producing bacterium of the present invention is Pseudomonas fluorescens KYM-1 strain (FERM P-11333) or Pseudomonas cepacia KYM.
-2 strain (FERM P-11334), Acinetobacter genus, Agrobacterium genus Agrobacterium KYM-4 strain (FERM P-11334)
P-11336), a bacterium belonging to at least one genus selected from the group consisting of the genus Enterobacter, the genus Aureobacterium, and the genus Oerscovia, and having the ability to produce a flocculant, which is a conventionally known Rhodococcus erythropoles KR-256
-2, FERM-P No. 3923 and Road Coccus
Erythropoles KR-S-1, FERM-P No.353
It belongs to a genus different from 0, and its aggregating ability is 2-3 times or more than those of these known bacteria.

Of these genera, Pseudomonas sp. Pseudomonas fluorescens KYM-1 strain or Pseudomonas cepacia KYM-2 strain, Acinetobacter spp.
In the present invention, a microorganism group containing at least one genus selected from the group consisting of Agrobacterium genus Agrobacterium KYM-4 strain (FERM P-11336), Enterobacter genus, Aureobacterium genus and Oerscovia genus is R-3 in the present invention. However, each of them has already been published by Micro Inst.
No. 11334), No. 11334 (FERM P-11334), No. 1
No. 1335 (FERM P-11335), No. 11336 (FERM P-
11336), No. 11337 (FERM P-11337), No. 113.
No. 57 (FERM P-11357) and No. 11358 (FERM P-11
358). The above flocculant-producing novel microorganism has the following mycological properties.

[0010]

[Table 1]

[0011]

[Table 2] (Continued from Table 1)

[0012]

[Table 3] (Continued from Table 1)

[0013]

[Table 4] (Continued from Table 1)

Regarding the mycological properties shown in Table 1 above, Bergey's Manual of System of Bacteriological Bacteology Vol.
Temic Bacteriology Volume 1, 2), (1984), the KYM-1 strain was consistent with Pseudomonas fluorescens described on page 165 of the same document, and KYM-
One strain was identified as Pseudomonas fluorescens and has been deposited as Microindustrial Research Institute No. 11333 (FERM P-11333). The KYY-2 strain is appropriate when considered to be Pseudomonas cepacia described on page 175 of the same document, and is based on
Deposited as 1334 (FERM P-11334). KY
The M-3 strain is consistent with the bacterium of the genus Acinetobacter described on page 303 of the same document, and has been deposited as Microindustrial Research Institute No. 11335 (FERM P-11335).

Although the description of KYM-4 strain is almost the same as that of Agrobacterium reideobacter described on page 254 of the same document, it is classified as a related species because it is slightly different in details such as sugar assimilation. It is scientifically valid, and this bacterium has been deposited as Microorganism Research Institute No. 11336 (FERMP-11336). The KYM-5 strain was completely in genus level with the Enterobacter bacteria described on page 465 of the same document, and was
Deposited as 1337 (FERM P-11337). KY
The M-6 strain is the same as the aureobacterium bacterium described on page 1323 of the same document, and the KYM-7 strain is the same as the Oerscovia bacterium described on page 1489 of the same document at the genus level. KYM
-6 strain is Microcosm Institute of Microbiology No. 11357 (FERM P-11357),
The KYM-7 strain is microbial strain No. 11358 (FERM P-11
358), respectively.

The flocculant of the present invention is mainly composed of a culture or a culture-treated product of the above-mentioned microorganism containing at least one genus, and the culture solution itself, a concentrate thereof, a filtrate, a filtration residue thereof, and the like. Any form such as dried product of
In addition, the aggregating ability can be further improved by incorporating one or more cationic inorganic salts such as calcium ions into the aggregating agent or by incorporating them at the time of use. The feature of the wastewater coagulation treatment method of the present invention is that at least one kind of the above-mentioned coagulant is used, and the wastewater to be applied may be any wastewater containing a suspended matter, but particularly activated sludge is used. In the wastewater coagulation treatment method, generation and growth of filamentous fungi, which are the main cause of bulking, can be suppressed in the separation area between activated sludge and treated water. Therefore, the present invention is particularly effective for treating wastewater in which filamentous fungi are easily generated in treated water.

The method for effluent coagulation treatment by the activated sludge system using microorganisms is well known, and the present invention can be applied to any of these well-known effluent coagulation treatment methods and is not particularly limited. In a preferred embodiment of the present invention, the pH in the separation area where the activated sludge and the treated water are to be separated is 7 to 9, particularly preferably 8.0.
By setting it in the range of 8.5, a more excellent force value can be obtained. In the present invention, the amount of the aggregating agent added is 0.5% by weight or more, preferably 0.5 to 10% by weight, as a culture solution. Even if the coagulant concentration was added in excess of 10%, the strength value did not improve depending on the amount added.

[0018]

Example A culture solution of each of the conventionally known Rhodococcus erythropoles and the flocculant-producing bacterium of the present invention was shake-cultured at 30 ° C. in the following liquid medium. The R-1 bacterium is a conventionally known Rhodococcus erythropoles, and the R-3 bacterium of the present invention is a KYM-1 strain (FERM P-11333), KYM-2.
Strain (FERM P-11334), KYM-3 strain (FERM P-11335), KY
M-4 strain (FERM P-11336), KYM-5 strain (FERM P-1133)
7), KYM-6 strain (FERM P-11357) and KYM-7 strain (FER
M P-11358).

Composition of liquid medium Carbon source 10 g / l K ₂ HPO ₄ 5 g / l KH ₂ PO ₄ 2 g / l MgSO ₄ 0.2 g / l (NH ₄ ) ₂ SO ₄ 0.5 g / l yeast extract 5 g / l NaCl 0.1 g / l

(1) Titer (a) Test solution Using fructose as a carbon source of the liquid medium, p
A culture solution obtained by shaking culture for 5 days in a medium in which H was adjusted to 8.5 was used as a test solution. The temperature was 30 ° C. (B) Evaluation method of force value 5000 mg of kaolin was added to a 100 ml measuring cylinder.
/ L (liter) liquid was added to 80 ml, a predetermined amount of inorganic kaolin and the culture liquid were added, and the mixture was gently inverted and stirred, and then 0.5
The pH was adjusted to pH 7.0 with N NaOH and HCl. Bring the total volume to 100 ml with distilled water, repeat stirring by inversion,
The OD ₅₅₀ of the supernatant water after 5 minutes of standing was measured, and 1 / D ₅₅₀
The cohesive titer was displayed at.

The daily changes in the agglutination titers of the R-1 and R-3 bacteria were as shown in FIG. As described above, the R-3 bacterium in the present invention exhibits a remarkably excellent titer as compared with other bacteria. Incidentally, R-1 is a conventionally known Rhodococcus erythropoles bacterium. (2) pH during aggregation The pH during aggregation was adjusted to 5 to 10 and the optimum aggregation pH was examined. OD ₅₅₀ is decreased as pH as shown in FIG. 2 rises from 5 8, OD ₅₅₀ in more pH
It was revealed that the optimum aggregation pH of the culture solution was 8.0 to 8.5.

[0022]

[Effects] As described above, according to the present invention, in a wastewater coagulation treatment method using activated sludge, by using a flocculant produced by a novel bacterium as a flocculant-producing bacterium,
The generation of filamentous fungi, which is the main cause of the bulking phenomenon, is suppressed, and the separation of activated sludge and treated water becomes efficient. In a further preferred embodiment, the pH of the separation area is set to a specific range, whereby the separation of activated sludge and treated water is significantly promoted.

[0023]

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between agglutination titer and the number of days elapsed.

FIG. 2 is a graph showing the relationship between agglutination titer and pH.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C12R 1:01) Examiner Yuko Saeki (56) References Japanese Patent Publication No. 52-31434 (JP, B1) Uemura Sadajiro et al., "Fermentation and Microorganisms III", Asakura Shoten Co., Ltd. (Sho 45.10.10) P. 135-166

Claims (7)

[Claims] 1. A Pseudomonas sp. Pseudomonas fluorescens KYM-1 strain (FERM P-11333) or a Pseudomonas cepacia KYM-2 strain (FERM P-11334), Acinetobacter sp., Agrobacterium sp. Agrobacterium KYM-4. Strain (FERM P-11336), Enterobacter, Genus Aureobacterium and Oelscovia genus, and at least one genus or one species selected from the group, or a culture or treated culture product of a flocculant-producing microorganism characterized by the above-mentioned. A microbe-produced flocculant containing as a main component. 2. The Acinetobacter genus is Acinetobacter KYM-3 strain (FERMP-11335), and the Enterobacter genus is Enterobacter KYM-5 strain (FERMP-11337).
The microbial production according to claim 1, wherein the genus Aureobacterium is the strain Aureobacterium KYM-6 (FERM P-11357), and the genus Oerscovia is the strain Oerscovia KYM-7 (FERM P-11358). Flocculant. 3. The microorganism-producing flocculant according to claim 1, which contains one or more cationic inorganic salts. 4. A wastewater coagulation treatment method, which comprises contacting the microbial-produced coagulant according to claim 1 with a suspension-containing wastewater. 5. In a wastewater coagulation treatment method using an activated sludge method, the microorganism-produced coagulant according to any one of claims 1 to 3 is present in a treatment system, and bulking of the activated sludge is performed in a separation area between activated sludge and treated water. A method for aggregating wastewater, which is characterized by preventing it. 6. The wastewater coagulation treatment method according to claim 4, wherein the pH of the separation area of the activated sludge is maintained at 7 to 9. 7. The wastewater coagulation treatment method according to claim 5 or 6, wherein the wastewater to be treated is wastewater that easily generates filamentous fungi.