JP3223841B2 - Aerobic treatment of waste liquid containing terephthalic acid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for aerobically treating a waste liquid containing terephthalic acid, particularly a waste liquid obtained by subjecting a polyester fiber fabric to an alkali reduction treatment, using the microorganism.

[0002]

2. Description of the Related Art Waste liquid discharged from processing and manufacturing processes of polyester fibers and polyester films mainly contains terephthalic acid and ethylene glycol. In particular, the waste liquid generated by the weight reduction processing of polyester fibers with a sodium hydroxide solution contains these at a high concentration.

At present, such waste liquid is generally treated by the activated sludge method. However, if the treatment is performed at a high concentration, bulking is likely to occur, and the sludge is set by installing a large treatment tank and diluting the waste liquid. It is necessary to reduce the load, so that the volume load cannot be increased, and it cannot be said that the treatment is performed efficiently. With the spread of new synthetic fibers, the processing amount of waste liquid for alkali weight reduction processing is also increasing,
It is considered that it is difficult to cope with an increase in the throughput by a general activated sludge method.

There is also a method of recovering terephthalic acid by sulfuric acid precipitation, but the recovered material does not withstand reuse and cannot be said to be an excellent method in terms of cost. Further, ozone treatment (Japanese Patent Application Laid-Open No. 6-269797) and wet oxidation treatment (Japanese Patent Application Laid-Open No.
No. 204666) has been disclosed, but the former requires the use of ozone and the latter requires the use of a catalyst and treatment under high-temperature and high-pressure conditions. Therefore, can the method be more cost-effective than the activated sludge method? Is questionable.

[0005] On the other hand, some microorganisms that decompose terephthalic acid can be found in the literature, but there are few descriptions concerning the degradable concentration and rate. For example, it has been reported that bacteria belonging to the genus Nocardia degraded terephthalic acid at an initial concentration of 0.25% to 0.09% in 24 hours (FEMS Microbiology Letters, 5).
245-251 (1979), a report that mentions that bacteria belonging to the genus Bacillus degraded terephthalic acid at a concentration of 0.2% in 24 hours (FEMS Microbiology Letters, Vol. 30, 217). ~ Page 220, 1
985), and in particular, knowledge on microorganisms that rapidly decompose terephthalic acid at a high concentration (0.5% or more) and microorganisms that decompose terephthalic acid at a high temperature of 40 to 55 ° C. I can't find it.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to develop a method for treating a terephthalic acid-containing waste liquid capable of treating a waste liquid containing a high concentration of terephthalic acid with a high load. The purpose is to realize a great efficiency by speeding up and downsizing.

[0007]

SUMMARY OF THE INVENTION The gist of the present invention to solve the above-mentioned problems is basically that "at least one terephthalic acid-decomposing microorganism and at least one terephthalic acid-non-degradable and terephthalic acid-degrading accelerator are accelerated. Bacillus sp.
Escherichia, Citrobacter, Erwinia,
Proteus, Alcaligenes, Agrobacterium
Genus, Staphylococcus, Pseudomonas, micro
Bacteria, Brevibacterium, Klebsiella
Genus, micrococcus, arthrobacter, hafnia
Genus, Acinetobacter, Xanthomonas, and
At least one genus selected from the group consisting of Lattia
A method for aerobically treating a terephthalic acid-containing waste liquid, comprising using a microorganism belonging to the group . "It is in.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The terephthalic acid-decomposing microorganism used in the present invention is not particularly limited by genus and species. Preferably, it has the ability to decompose 95% or more within 5 days. Further, for example, Pseudomonas genus bacteria (Biotechnological Laboratory No. 15544, C4S strain), Alcaligenes bacterium (Biotechnological Research Laboratories No. 16154, K1 strain), and Rhodococcus genus bacteria (Biotechnological Corp.) obtained by the present inventors. No. 16213, L1 strain)
Etc. are preferably used.

It has been found that terephthalic acid can be decomposed even when these microorganisms are used alone, but when a specific microorganism having no terephthalic acid decomposability is used at the same time, the decomposition rate is remarkably improved. Microorganisms that are not terephthalic acid-degrading and have terephthalic acid decomposition promoting properties are not particularly limited. A bacterium whose decomposition is 5% or less by itself, and a bacterium having the ability to promote the terephthalic acid decomposition rate of terephthalic acid-decomposing bacteria alone by at least 5% or more when coexisting with terephthalic acid-decomposing bacteria. It is preferred that More preferably, the accelerating ability is 20% or more.
The mechanism by which these microorganisms promote terephthalic acid degradation is not known, but the fact that these microorganisms assimilate and remove metabolites of terephthalic acid-degrading bacteria is itself effective in promoting it. It is also presumed that they produce a compound that promotes the terephthalic acid decomposition system when assimilating metabolites and supply it to terephthalic acid-decomposing bacteria. Microorganisms having such a promoting effect are not particularly limited, but include Bacillus, Escherichia, Citrobacter, Erwinia, Proteus, Alcaligenes, Agrobacterium,
Staphylococcus, Pseudomonas, Microbacterium, Brevibacterium, Klebsiella,
Micrococcus, Arthrobacter, Hafnia,
A microorganism belonging to the genus Acinetobacter, Xanthomonas or Serratia can be exemplified. Above all, Bacillus, Escherichia, Citrobacter, Erwinia, Proteus, Agrobacterium, Pseudomonas and Brevibacterium are preferred, and Bacillus, Citrobacter, Pseudomonas and Brevibacterium are particularly preferred.

The mode of using the terephthalic acid-degrading microorganism and the microorganism that is non-terephthalic acid-degrading and has terephthalic acid decomposition-promoting properties is not particularly limited as long as the terephthalic acid decomposition-promoting effect is observed. It is the simplest and most effective to mix and use them simultaneously.
However, if the effect is exerted, for example, both bacteria may be used spatially or temporally separately so that chemical substances can come and go but bacteria cannot.

The waste liquid to be treated in the present invention contains terephthalic acid, and is typically a terephthalic acid production step and a waste liquid for alkali reduction of polyester fiber fabric. The waste liquid contains ethylene glycol, sodium hydroxide, other inorganic substances and organic substances other than terephthalic acid, but these do not hinder the decomposition treatment ability of the present invention. If necessary, ammonia water, ammonium sulfate,
Compounds selected from organic and inorganic nitrogen sources such as salt and salt, phosphorus and sodium, sodium nitrate, ammonium nitrate, potassium nitrate, meat extract, yeast extract, peptone, and magnesium salt, potassium salt, phosphoric acid (salt), iron salt, A compound selected from other metal salts and the like is added.

The waste liquid treated in the present invention preferably contains terephthalic acid in an amount of 0.5% or more, more preferably 0.6% or more, and further preferably 0.8% or more.
That is all. The upper limit is not particularly limited, but is preferably 4.0% or less, more preferably 2.0% or less.

The proportion of terephthalic acid in a nutrient source or a carbon source in terms of BOD is not particularly limited, but is preferably 21% or more, more preferably 63% or more, and further preferably 70%. Above, particularly preferably at least 74%. Further, ethylene glycol may be contained as another carbon source in the waste liquid to be treated.

[0014] More preferably, the ethylene glycol contained therein is simultaneously decomposed. It has been found that ethylene glycol-degrading microorganisms that can be separately obtained can simultaneously treat ethylene glycol during the continuous decomposition of terephthalic acid in waste water of a polyester fiber woven fabric subjected to alkali weight reduction processing. The bacteriological properties of this strain are shown below.

(A) Morphological properties (1) Cell shape and size: Bacillus (0.5-0.7 × 0.9-1.2 μm) (2) Motility (flagellate): Yes (one pole (Flagellate) (3) Spores: no (b) Cultural properties (1) Broth agar plate culture: brownish, matte surface. Translucent. About 3 mm in diameter in 2 days. The center is slightly raised.

(2) broth liquid culture: medium turbidity (3) broth gelatin stab culture: does not liquefy (4) litmus milk: does not coagulate (c) physiological properties (1) Gram stainability:-(2) nitrate Reduction of +: (3) Denitrification reaction:-(4) MR test:-(5) VP test:-(6) Formation of indole:-(7) Formation of hydrogen sulfide:-(8) Hydrolysis of starch :-(9) Utilization of citric acid: + (Christensen medium) (10) Inorganic nitrogen source: + (both ammonia and nitrate) (11) Pigment formation:-(12) Urease:-(13) Oxidase: + (14) Catalase: + (15) Range of growth: Temperature 30 ° C: ○, 50 ° C: ○, 55 ° C: × pH 6.0 to 10.0 (16) Attitude to oxygen: Aerobic (17) OF test: -(18) Generates acid but not gas from glycerin. Both acid and gas are generated from L-arabinose, D-xylose, D-glucose, D-mannose, D-fructose, D-galactose, maltose, sucrose, lactose, trehalose, D-sorbitol, D-mannitol, inositol and starch. do not do.

[0017] The above results were obtained from the Barjay's Manual
Of the systematic bacteriology. This strain is a gram-negative, aerobic, bacillus, a catalase and oxidase-positive bacterium belonging to the genus Pseudomonas sp. It was named K4. The bacterium is characterized in that it retains the ability to accelerate the decomposition rate of terephthalic acid-decomposing bacteria.

The temperature at which the waste liquid is treated using the present invention is not particularly limited, but is not less than 30 ° C. and 60 ° C.
C. or less is preferred. In consideration of utilization at an optimum treatment rate and prevention of various bacterial contamination, 45 to 55 ° C is more preferable.

When the treatment tank is actually operated, it is preferable that the temperature is constantly and stably maintained in order to stabilize the activity of microorganisms involved in the decomposition of terephthalic acid and to prevent contamination of various bacteria. Although it is not particularly limited, it is preferable that the temperature does not drop below the above temperature condition for one month or more, and more preferably does not drop below 45 ° C. for one month or more. In addition, particularly under high temperature conditions, a slight increase in temperature may adversely affect the decomposition activity and the growth of microorganisms. Therefore, the stability of the set temperature is important. The temperature fluctuation is preferably within 5 ° C, more preferably within 2 ° C.

In particular, in the aerobic treatment of terephthalic acid-containing waste liquid, the iron ion activity in the liquid to be treated is preferably 3 μM or more, more preferably 10 μM or more, and 5 μM or more.
0 μM or more is particularly preferred. The adjustment of the concentration is not particularly limited, and a powder or solution of a salt of a divalent ion or a trivalent ion may be added, or more simply, a metal or an iron solid such as an oxide may be added to the treatment tank. Alternatively, it may be arranged in a pipe so as to be in contact with the processing liquid, and arranged so that iron ions can be released.

The treatment is carried out at a pH of 6.0 to 9.5, preferably 6.5 to 8.5. Since the pH of the processing solution increases due to the decomposition of terephthalic acid, the pH is adjusted with an acid such as sulfuric acid.

Since an aerobic microorganism is used, the treatment method of the present invention uses an aerobic treatment method. The aerobic treatment method is not particularly limited, and oxygen may be supplied. The supply source may be oxygen gas or oxygen-enriched gas in addition to ordinary air, and is supplied by a method such as stirring, ventilation stirring, and air lift. Unless the dissolved oxygen is extremely low, the rate of decomposition is not limited.

The mode of the waste liquid treatment is not particularly limited. Of course, the waste liquid may be used alone, may be mixed with another waste liquid if necessary, or only the terephthalic acid waste liquid may be used. Once collected, the terephthalic acid component may be completely or largely degraded and then subjected to other general microbial treatments. Alternatively, treatment may be performed in multiple stages from a tank having a high terephthalic acid concentration to a tank having a low terephthalic acid concentration.

Hereinafter, the present invention will be specifically described with reference to examples.

[0025]

【Example】

[Example 1] Terephthalic acid 0.6%, monopotassium phosphate 0.15%, magnesium sulfate heptahydrate 0.02%, ferrous sulfate heptahydrate 0.002%, bactotripton (Dif
co) 0.2%, liquid medium containing 0.2% yeast extract (p
H6.5) 5 ml was dispensed and sterilized in a medium test tube, and Alcaligenes sp. K1 was inoculated, and the bacterial species shown in Table 1 (previously confirmed to have no terephthalic acid degradability) were inoculated, and shaking culture was performed at 30 ° C. or 45 ° C. Table 1 shows the terephthalic acid concentration (measured by the absorption amount at 240 nm) remaining in the medium after 24 hours or 48 hours of the culture.

[0026]

[Table 1] Example 2 Pseudomonas sp. Using C4S,
The same experiment as in Example 1 was performed. The results are shown in Table 2.

[0027]

[Table 2] Example 3 Rhodococcus sp. The same experiment as in Example 1 was performed using L1. The results are shown in Table 3.

[0028]

[Table 3] [Example 4] In a 2 L culture tank, an inorganic salt (ammonium sulfate, 2 g; phosphoric acid, etc.) was used as an alkali weight reduction waste liquid of polyester containing 0.8% terephthalic acid and 0.3% ethylene glycol.
0.2 g; magnesium sulfate heptahydrate, 0.08 g; potassium chloride, 0.08 g; ferrous sulfate heptahydrate, 2 mg)
Was added, and the K1 strain and Pseudomonas sp. K4 strain was inoculated and aerated and stirred at 50 ° C. (1 vv
m, 600 rpm). The pH was controlled at 7.5 with sulfuric acid. Further, while maintaining the culture solution at 1 L, the above-mentioned medium (total organic carbon content is about 5.8 g / L) was continuously fed for 200 m.
Addition was carried out at a flow rate of 1 / h, and acclimation was continued. When the total amount of organic carbon in the discharged culture solution was measured, it was always 100 pp.
m or less, and both terephthalic acid and ethylene glycol were almost decomposed.

[0029]

EFFECT OF THE INVENTION When directly treating a waste solution containing a high concentration of terephthalic acid aerobically, not only terephthalic acid degrading bacteria but also
By coexisting other terephthalic acid non-degrading microorganisms, the decomposition of terephthalic acid can be remarkably promoted, and as a result, terephthalic acid can be stably and efficiently decomposed.

For example, when this process is incorporated as a pretreatment into a general activated sludge treatment facility for terephthalic acid-containing wastewater, the wastewater treatment capacity of the facility can be greatly increased at low cost and space saving. . In addition, if a new waste liquid treatment facility is newly established,
Cost reduction has become possible.

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) C12N 1/00-1/38 C02F 3/34 BIOSIS (DIALOG) WPI (DIALOG)

Claims (9)

(57) [Claims] At least one terephthalic acid-degrading microorganism and at least one terephthalic acid non-degrading and terephthalic acid decomposition-promoting bacterium, Escherichia
Genus, Citrobacter, Erwinia, Proteus
Genus, Alcaligenes, Agrobacterium, Stuff
Irococcus, Pseudomonas, Microbacterium
Genus, Brevibacterium, Klebsiella, micro
Coccus, Arthrobacter, Hafnia, Acinet
Genus Tobacco, Xanthomonas, and Serratia
A method for aerobically treating a terephthalic acid-containing waste liquid, comprising using a micro-organism belonging to at least one genus selected from the group consisting of: 2. The method for aerobically treating a terephthalic acid-containing waste liquid according to claim 1, wherein the terephthalic acid-degrading microorganism belongs to the genus Pseudomonas, the genus Alcaligenes, or the genus Rhodococcus. 3. The method of claim 1, wherein the terephthalic acid-degrading microorganism is Pseudomonas sp. C4S (Biotechnological Laboratory No. 15544), Alcaligenes sp. K1 (16154)
No.), and Rhodococcus sp. 3. The method for aerobically treating a terephthalic acid-containing waste liquid according to claim 2, which is at least one selected from the group consisting of L1 (Biotechnological Laboratories No. 16213). Wherein the treatment temperature is 30-55 claims 1 to the processing method of the terephthalic acid-containing waste liquid according to claim 3, wherein the a ° C.. 5. A process according to claim 1 to high-temperature aerobic treatment method terephthalic acid-containing waste liquid according to claim 3, wherein the temperature is 45 to 55 ° C.. 6. aerobic treatment method according to claim 1 is 5, wherein the terephthalic acid-containing waste liquid, characterized in that terephthalic acid concentration of the waste is 0.5% or more. Upon 7. The method of claim 1 or aerobic treatment of terephthalic acid-containing waste liquid of the sixth aspect, the iron ions in the liquid to be treated 3
A method for treating terephthalic acid-containing waste liquid, which is added at a concentration of at least μM. 8. The effluent of claim 1, wherein the effluent is a waste liquor of alkali fiber reduction processing of polyester fiber fabric.
8. The method for aerobically treating a terephthalic acid-containing waste liquid according to claim 7 . 9. The method for aerobically treating a terephthalic acid-containing waste liquid according to claim 8 , wherein a microorganism belonging to the genus Pseudomonas and having the ability to degrade ethylene glycol is used simultaneously.