JPH0564796A - Removal of dimethylamine - Google Patents

Abstract

PURPOSE:To efficiently make a harmful waste fluid containing dimethylamine harmless by decomposing and removing dimethylamine by bringing a factory waste fluid containing dimethylamine into contact with cells of bacteria belonging to the genus Xanthobacter and metabolizing and decomposing dimethylamine and/or cell treated matter of said bacteria. CONSTITUTION:A factory waste fluid containing dimethylamine is brought into contact with cells of bacteria (e.g; Xanthobacter autotrophicus) belonging to the genus Xanthobacter and capable of metabolizing and decomposing dimethylamine and/or cell treated matter of said bacteria to decompose and remove dimethylamine. As a result, a harmful waste fluid containing dimethylamine can be effectively made harmless.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing and removing dimethylamine in a liquid containing dimethylamine, and more specifically, using bacterium to remove dimethylamine in a liquid containing dimethylamine. It is related to the method of disassembly and removal.

2. Description of the Related Art Dimethylamine is contained in the waste liquid of a dimethylamine manufacturing plant. Further, since dimethylamine is also a decomposition product of dimethylformamide, dimethylformamide is also contained in the waste liquid of the factory that handles dimethylformamide. Waste liquids containing these dimethylamines are harmful and must be discharged after being detoxified for environmental hygiene. As a method for decomposing and removing dimethylamine in a waste liquid containing dimethylamine, for example, JP-B-54-1
There is a method described in Japanese Patent No.792. This method is a method of decomposing it using an enzyme in the cells of a microorganism belonging to the genus Micrococcus, but its processing capacity is insufficient for practical use. If this stable and difficult-to-decompose dimethylamine can be efficiently assimilated and a microorganism capable of decomposing can be found, it becomes possible to effectively detoxify the waste liquid containing dimethylamine using this microorganism.

[0002]

As a result of extensively searching the natural world, the present inventors have completed the present invention by finding a microorganism that actively assimilates dimethylamine and strongly decomposes it. That is, the present invention, by contacting a liquid containing dimethylamine, a bacterial cell of a bacterium belonging to the genus Xanthobacter that can assimilate dimethylamine and / or a treated product of the bacterial cell of the bacterium, and A method for removing dimethylamine, which comprises decomposing and removing dimethylamine in a liquid. The bacterium used in the present invention is not particularly limited as long as it belongs to the genus Xanthobacter and is a strain having the ability to efficiently assimilate and decompose dimethylamine. Typical examples of these strains include Xanthobacter autotrophicus DSM.
432 and Xanthobacla flavus (Xanthobac
ter flavus) DSM 338 (= NCIB 1007
There is 1). These strains are known, and DSM (Deu
It is available from preservation organizations such as tsche Samnlung Von Mikroorganismen). Key Santo Enterobacter bacteria, key Santo Enterobacter auto For Toro ficus and yellow Santo Enterobacter flavus "Bajizu manual of systematic Bact ^(Bergey, s Manu
al of Systematic Bacteriology) Volume 1, Editors Krieg and Holt, Williams and Wilki
ns company, 1984 ”.

A dimethylamine-containing agar plate medium and a dimethylamine-containing agar slant medium for growing the strain were prepared as follows. That is, (NH
₄ ) ₂ SO ₄ 3 g, KH ₂ PO ₄ 1.4 g, Na _{2
HPO 4 2.1g, MgSO 4 · 7H} 2 O 0.2
g, CaCl ₂ .2H ₂ O 30 mg, FeC ₆ H ₅ O
₇ · xH ₂ O 30mg, MnCl ₂ · 4H ₂ O 5m
_{g, ZnSO 4 · 7H 2 O} 5mg, CuSO 4 · 5H
_After adding 0.5 mg of ₂ O and 0.2 g of yeast extract and adjusting the pH to 7.1, 15 g / l of agar was further added and dissolved by heating, and then 1 Kg / cm ²
Sterilized in G for 20 minutes. As the dimethylamine-containing liquid medium, the medium having the above composition without the addition of agar was used. In order to detoxify a liquid containing dimethylamine (hereinafter sometimes referred to as a treatment liquid), various nutrient components are added to the liquid to be treated, which is used as a medium and belongs to the genus Xanthobacter. There is a method of culturing a bacterium capable of assimilating and decomposing dimethylamine (hereinafter referred to as the present bacterium).
That is, the nutrient added to the liquid to be treated may be any substance that can be assimilated by the present bacterium to be used, and is not particularly limited and includes a carbon source, an inorganic component and other components.

As the carbon source, only dimethylamine in the liquid to be treated may be used, but other carbon sources that can be assimilated by the bacterium used, for example, saccharides such as L-arabinose, D-glucose and D-galactose. , Sugar alcohols such as glycerol, organic acids such as acetic acid, and amines such as monomethylamine and trimethylamine can also be used in combination. As the nitrogen source, for example, inorganic nitrogen compounds such as ammonium salts, alkylamines, organic nitrogen-containing substances such as corn steep liquor, casein, peptone and meat extract are used. Since dimethylamine is a nitrogen compound, any bacterium can sufficiently grow and proliferate and assimilate and decompose dimethylamine without adding any other nitrogen source. As the inorganic components, for example, calcium salts, potassium salts, magnesium salts, phosphates, manganese salts, zinc salts, iron salts, copper salts, molybdenum salts, cobalt salts, boron compounds, iodine compounds and the like are used. Further, when using a strain that requires a nutritional substance such as vitamins, the nutritional substance required by the strain is added.

The concentration of dimethylamine in the treatment liquid is not particularly limited as long as it can assimilate and decompose the used strain of the present invention, but is usually 1.5 wt% or less, preferably 1 wt% or less. Particularly preferred. The culture conditions may be such that the bacteria used can grow and proliferate, but in general,
For example, the temperature is 10 to 37 ° C, preferably 15 to 37.
C. and pH is 6-9, preferably 6.5-8.0.
It is said that. By aerobically culturing the bacterium under such conditions, dimethylamine is decomposed, the dimethylamine in the liquid to be treated is reduced or disappeared, and the bacterium is smoothly grown. The cell concentration of the liquid to be treated during the decomposition treatment by culture cannot be unconditionally specified, but the higher the cell concentration, the higher the dimethylamine decomposition rate, and in practice, the content of dimethylamine in the liquid to be treated ( It is preferably 1/5 or more of the weight) (converted to dry cells). Further, the dissolved oxygen concentration is not particularly limited as long as it is the dissolved oxygen concentration at the time of the decomposition treatment by culture, and it is the same as the dissolved oxygen concentration in the usual culture of bacteria.
In order to obtain the desired dissolved oxygen concentration, the amount of aeration gas is adjusted, stirring is performed, oxygen gas or a mixed gas of oxygen and air is used as an aeration gas, and the pressure in the culture tank is increased. The usual means of is adopted. The treatment method may be batch, continuous or semi-continuous.

In addition to the method of detoxifying dimethylamine in the liquid to be treated by culturing the bacterium using the liquid to be treated as a medium as described above, cells of the bacterium and the bacterium which have been precultured are also used. Treated cells-for example, crushed cells of the bacterium and immobilized cells obtained by immobilizing the cells of the bacterium with a synthetic resin or the like- (these may be collectively referred to as cells below. It is also possible to contact the liquid to be treated. For example, (a) adding bacterial cells to the liquid to be treated
(B) Contacting the liquid to be treated with the activated sludge in which the cells, the culture solution and the crushed material of the cells are mixed, and (c) the liquid to be treated in the column filled with the immobilized cells. There are methods such as passing it. In the methods (a) and (b), the amount of bacterial cells used is not particularly limited, but in order to perform the treatment in a short time, it is usually 0.1 g or more per 1 l of the liquid to be treated in practice. (The same applies to the case of dry cells), preferably about 0.1 to 10 g. In the method of (c), the enzyme or the bacterial cell is immobilized by a usual method such as a carrier binding method, a cross-linking method and an entrapping method. In order to perform the treatment more efficiently, it is more preferable to use immobilized cells, in which case collagen, polymer gels such as carrageenan and polyurethane, microcapsules such as collodion and phospholipids or ultrafiltration membranes are used. A method of confining the body is performed. In any of (a), (b), and (c), the dimethylamine concentration in the liquid to be treated, the temperature and pH, etc. are the same as in the case of the decomposition treatment by culture.

Since the waste liquid containing dimethylamine often contains other substances, a microorganism capable of decomposing other substances together with the bacterium is used in the treatment of such waste liquid. It can be used in combination and is preferable. After the decomposition treatment, the treated liquid in which the concentration of dimethylamine in the liquid to be treated has been reduced to the permissible concentration or less is discharged as it is or after removing the bacterial cells and / or the treated bacterial cells as necessary. To be done.

[0008]

EXAMPLES The present invention will be described in more detail by way of examples. The present invention is not limited to these examples. Example 1 (NH ₄ ) ₂ SO ₄ 3 g, KH ₂ P per 1 L of pure water
O ₄ 1.4 g, Na ₂ HPO ₄ 2.1 g, MgSO
_{4 · 7H 2 O 0.2g, CaCl} 2 · 2H 2 O 30
mg, FeC ₆ H ₅ O ₇ xH ₂ O 30 mg, MnC
_{l 2 · 4H 2 O5mg, ZnSO} 4 · 7H 2 O5mg,
CuSO ₄ .5H ₂ O 0.5 mg and yeast extract
A medium prepared by adding 0.2 g and adjusting the pH to 7.1 was used as a basal medium, and a predetermined amount of dimethylamine was added to the basal medium to prepare a medium. Each of these media should be treated with Xanthobacter autotrophicus.
otrophicus) DSM 432 and Xanthobacter flavus DSM 338 were inoculated and cultured at 30 ° C. for 7 days to examine the assimilation and degradability of dimethylamine. It can be seen from Table 1 that even a treatment liquid having a high concentration of dimethylamine can be effectively rendered harmless by the present invention.

[Table 1] Table 1 Dimethylamine-assimilating strain Dimethylamine concentration (wt%) 0.2 0.3 0.5 0.7 0.8 1.0 1.5 DSM 432 ++ ++ ++ ++ ++ ++ + -DSM 338 ++ ++ ++ ++ + + ++ +- ++: Utilizes actively. +: Utilize. -: Not assimilated.

Example 2 (NH ₄ ) ₂ SO ₄ 3 g, KH ₂ P per 1 L of pure water
O ₄ 1.4 g, Na ₂ HPO ₄ 2.1 g, MgSO
_{4 · 7H 2 O 0.2g, CaCl} 2 · 2H 2 O 30
mg, FeC ₆ H ₅ O ₇ xH ₂ O 30 mg, MnC
_{l 2 · 4H 2 O5mg, ZnSO} 4 · 7H 2 O 5m
_{g, CuSO 4 · 5H 2 O} 0.5mg, yeast extract
0.2 g and 5 g of dimethylamine were added, and the pH was adjusted to 7.
200 mL of the medium adjusted to 0 was placed in a 1 L Erlenmeyer flask and sterilized at 120 ° C. for 20 minutes. To this medium, a preculture liquid of Xanthobacter autotrophicus DSM 432 (cell concentration OD ₆₁₀ 1.4) obtained by pre-culturing in a medium similar to this was adjusted to 1 vol%. The cells were inoculated and cultured at 30 ° C for 30 hours. The pH of the obtained culture broth was 8.0, and the bacterial cells of this bacterium were added to the culture broth 1.
It contained about 1.2 g per L. In addition, dimethylamine was not detected in the culture supernatant. The generation time was about 3.4 hours.

Example 3 (NH ₄ ) ₂ SO ₄ 3 g, KH ₂ P per 1 L of pure water
O ₄ 1.4 g, Na ₂ HPO ₄ 2.1 g, MgSO
_{4 · 7H 2 O 0.2g, CaCl} 2 · 2H 2 O 30
mg, FeC ₆ H ₅ O ₇ xH ₂ O 30 mg, MnC
_{l 2 · 4H 2 O5mg, ZnSO} 4 · 7H 2 O5mg,
CuSO ₄ · 5H ₂ O 0.5mg, yeast extract 0.2
g and 5 g of dimethylamine were added, and 200 mL of the medium adjusted to pH 7.0 was placed in a 1 L Erlenmeyer flask,
Sterilized at 120 ° C. for 20 minutes. A pre-cultured solution of Xanthobacter flavus DSM 338 (cell concentration OD.
₆₁₀ 1.2) inoculated to 1 vol%, 30
Incubated at 30 ° C. for 30 hours. The obtained culture broth had a pH of 7.5, and the bacterial cells of this bacterium were about 1.1 per liter of the culture broth.
g was included. In addition, dimethylamine was not detected in the culture supernatant. The generation time was about 5.2 hours.

Example 4 In the same manner as in Example 2, Xanthobacter autotrophicus DSM 432 was cultured and decomposed with dimethylamine. The obtained culture solution had a pH of 8.0 and contained about 1.1 g of the bacterial cells of this bacterium per 1 L of the culture solution. In addition, dimethylamine was not detected in the culture supernatant. The generation time was about 4.5 hours.

Example 5 1.5 L of the basal medium of Example 1 was placed in a 3 L jar fermenter and sterilized at 120 ° C. for 20 minutes, and then 15 g of dimethylamine was aseptically added to obtain a medium. 1 vol% of a preculture liquid of Xantobacter autotrophicus DSM 432 (cell concentration OD ₆₁₀ 1.2) obtained by previously culturing in this medium in the same medium.
And the cells were cultured at 30 ° C. for 24 hours. The bacterial cell concentration of the culture solution was 0. D. _{At 610} , when it reached 5.0 to 6.0, continuous treatment of an aqueous solution containing 0.6 wt% of dimethylamine was started. Continuous treatment has an average residence time of 12
The liquid to be treated was supplied to the treatment tank so that the time was reached, and an equal amount of the treatment liquid was withdrawn from the treatment tank. For the pH adjustment during the continuous treatment, a 2N hydrochloric acid aqueous solution was used. As a result, dimethylamine was not detected in the treated liquid.
The amount of bacterial cells of the bacterium contained in the treatment liquid was about 1.4 g per 1 L of the treatment liquid, and the COD value of the supernatant obtained by removing the bacteria from the treatment liquid was 200 ppm and the TOC value was 200.
It was ppm. In this decomposition treatment, the dissolved oxygen concentration of the treatment liquid was kept at about 2 to 4 ppm.

Example 6 1.5 L of the basal medium of Example 1 was placed in a 3 L jar fermenter and sterilized at 120 ° C. for 20 minutes, and then 15 g of dimethylamine was aseptically added to obtain a medium. This medium was inoculated with a pre-cultured solution of Xanthobacter flavus DSM 432 (cell concentration OD ₆₁₀ 1.2) obtained by pre-culturing in the same medium as 1 vol%. And cultured at 30 ° C. for 24 hours. The bacterial cell concentration of the culture solution was 0. D. _{At 610} , when it reached 5.0 to 6.0, continuous treatment of an aqueous solution containing 0.6 wt% of dimethylamine was started. The continuous treatment was performed while supplying the liquid to be treated to the treatment tank so that the average residence time was 12 hours, and withdrawing an equal amount of the treatment liquid from the treatment tank. PH during continuous processing
For the adjustment, a 2N hydrochloric acid aqueous solution was used. As a result, dimethylamine was not detected in the treated liquid. In addition, the amount of bacterial cells of the bacterium contained in the treatment liquid was about 1.1 g per 1 L of the treatment liquid, and C of the supernatant liquid obtained by removing the bacteria from the treatment liquid was C.
The OD value was 190 ppm and the TOC value was 200 ppm. In this decomposition treatment, the dissolved oxygen concentration of the treatment liquid was kept at about 2 to 4 ppm.

Example 7 In the same manner as in Example 5, the dimethylamine aqueous solution was continuously treated with an average residence time of 10 hours. The separated bacterial cells collected by centrifugation of the treated solution were frozen and stored at -20 ° C. 0.2 g of the above-mentioned frozen cells was added as a dry weight to 1 L of a liquid to be treated obtained by adding dimethylamine to a concentration of 0.6 wt%, and dimethylamine was decomposed at 30 ° C. Dimethylamine in the liquid to be treated decreased almost linearly with the passage of time, and was not detected 8 hours after the reaction started. The treatment rate of dimethylamine per gram of cells was about 7 g / hr.

Example 8 1 L of industrial waste liquid containing 0.6 wt% of dimethylamine was added.
H was adjusted to 7.0, and 0.5 g of the frozen microbial cells obtained in the same manner as in Example 5 was added as the dry microbial cell weight to give 3
Dimethylamine was decomposed at 0 ° C. Reaction start 8
No dimethylamine was detected after hours.
In each of the above Examples, the amount of dimethylamine in the liquid was analyzed by ion chromatography. Model: Toyo Soda CM-800 Column: TSKgel IC-Cation
4.6 mm × 5 cm Carrier: 2 mM HNO ₃ flow rate: 1 mL / min

[0016]

EFFECTS OF THE INVENTION According to the present invention, it is possible to efficiently decompose and remove dimethylamine, which is a stable substance that is difficult to decompose and is harmful, and to efficiently remove harmful waste liquid containing dimethylamine. Can be done, and the value for environmental hygiene preservation is extremely high.

Claims (1)

[Claims] 1. A solution containing dimethylamine is brought into contact with a bacterial cell of a bacterium belonging to the genus Xanthobacter that can assimilate and decompose dimethylamine and / or a treated product of the bacterial cell of the bacterium, and the solution is in the solution. A method for removing dimethylamine, which comprises decomposing and removing dimethylamine.