JPH0231887A - Method for removing phenol and aromatic amine from aqueous solution - Google Patents

Abstract

PURPOSE:To economically remove phenols and(or) aromatic amines from the aq. soln. thereof with a small amt. of catalyst by reacting hydrogen peroxide kept at a specified concn. with the org. compds. above-mentioned in the presence of peroxidase as catalyst. CONSTITUTION:The peroxidase is dissolved in a phenol aq. soln. and hydrogen peroxide is added at intervals of fixed time period. Thereby, the concn. of the hydrogen peroxide is constantly kept at 10m mol/l. Thus about 98% of the phenol can be removed in the first period of about 60min from the start if reaction. When >= 98% phenol is removed, it requires about 200,000 purpurogallin units/l expensive peroxidase according to a conventional method, but it can be done with about 150,000 purpurogallin units/l by the present method.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for removing phenols and aromatic amines from an aqueous solution, and more specifically, the present invention relates to a method for removing phenols and/or aromatic amines from an aqueous solution. It relates to a method of removing hydrogen peroxide by reacting with it.

[Prior art] In a method for removing phenols and aromatic amines contained in an aqueous solution, these substances are reacted with hydrogen peroxide using peroxidase as a reaction catalyst, and removed from the aqueous solution as an insoluble polymer. The method of doing this is described in, for example, Science (5science), Vol.
No. 7, pp. 259-261 (1983). This paper specifically examines the removal of phenol in detail, and shows that the amount of phenol in the solution is 0.01 to 5 g/
It is said that this method is effective in the concentration range of I, and that 98% of phenol in an aqueous solution can be removed.

The amount of peroxidase required to remove phenol from an aqueous solution with a phenol concentration of 19/I is 20.000 purprogalin units per 1 ft of aqueous solution, the hydrogen peroxide value is 20 mm0+ per 1 ft of aqueous solution, and the phenol concentration is 0.
01~5g/! If the amount of peroxidase and hydrogen peroxide is increased or decreased, the required amounts of peroxidase and hydrogen peroxide will need to be increased or decreased in proportion to the phenol concentration. For example, phenol concentration 5g/
! In the case of an aqueous solution of
00 mmol will be the bottle required for removal.

The results of studies on other phenols and aromatic amines such as aniline are published in the Journal of Applied Biochemistry.
ied Biochemistry), No. 21. 4
14-421 (1980). In addition, instead of adding hydrogen peroxide itself to an aqueous solution, a method in which an enzyme that produces hydrogen peroxide as a reaction product, such as glucose oxidase or alcohol oxidase, and its substrate are added to an aqueous solution together with peroxidase is also a special method. This is disclosed in Japanese Patent Publication No. 59-213494.

[Problems to be Solved by the Invention] A problem with such a method for removing phenols or aromatic amines from an aqueous solution is the removal cost, and a large proportion of this is due to the removal of phenols or aromatic amines from an aqueous solution. This is the cost of the enzyme. In particular, when dealing with aqueous solutions containing high concentrations of phenols and/or aromatic amines, the amount of peroxidase required becomes large and the removal cost becomes substantial, making the practical use of this method economical. Sexually difficult and rare.

The present invention has been made in response to the conventional circumstances as described above, and is intended to significantly reduce the amount of peroxidase used (
), it is an object of the present invention to provide a method for removing phenols and aromatic amines from an aqueous solution that can be used practically.

[Means for Solving the Problems] The present invention provides a method for removing phenols and/or aromatic amines in an aqueous solution by reacting them with hydrogen peroxide in the presence of peroxidase, in which the concentration of hydrogen peroxide in the aqueous solution is reduced. This is a method for removing phenols and aromatic amines from an aqueous solution, characterized in that the reaction is carried out while always maintaining the amount of phenols and aromatic amines at 10 mmol/11 or less.

[Operation] Hydrogen peroxide is an essential chemical substance in the method of removing phenols and/or aromatic amines from an aqueous solution by reacting with hydrogen peroxide using the catalytic action of peroxidase. If present, it has the effect of deactivating peroxidase.

However, as the concentration of phenols, etc. to be removed increases, the amount of hydrogen peroxide required also increases, as described in the prior art section, and if this amount is added to the aqueous solution at once,
The concentration of hydrogen peroxide in the aqueous solution also increases;
When the amount of peroxidase exceeds 10 mmol/ρ, peroxidase deactivation results in a decrease in the removal rate of the substance to be removed. Therefore, in order to achieve a predetermined removal rate, the amount of peroxidase must be increased.

On the other hand, the concentration of hydrogen peroxide added to the aqueous solution decreases as the removal reaction progresses. Therefore, initially 10mno
If hydrogen peroxide is added to the concentration below +/ρ and then gradually added to replenish the amount of hydrogen peroxide that has decreased as the removal reaction progresses, the concentration can be increased. The deactivation of peroxidase due to contact with hydrogen peroxide can be minimized, and the amount of peroxidase required for removal can be reduced.

[Example] Examples of the present invention will be described below.

10g/j! Peroxidase in phenol aqueous solution 12 (manufactured by Wako Pure Chemical Industries, Ltd., 100 purpurogalin units/η standard)
After dissolving 50 mg (5,000 purpurogalin units), 0.1 ml of 30 wt% hydrogen peroxide solution was added to the phenol solution every 30 seconds. Immediately after adding hydrogen peroxide,
The hydrogen peroxide concentration in the phenol aqueous solution is 0.98 mmo
l/fl, and by the time the next addition of hydrogen peroxide solution (after 30 seconds) has occurred, the peroxidase reaction has reduced the concentration to 0 mm01/fl.
, 1! Became. FIG. 1 shows the change in phenol concentration in an aqueous phenol solution over time.

As can be seen from the figure, 60 minutes after the start of the reaction, the phenol concentration was 2001F1g#! 98% of the phenol originally present was removed. The total amount of hydrogen peroxide added during that time was about 0.12 mol.

An example in which the method of the present invention was applied to an aqueous phenol solution has been described above, but the fact that the method of the present invention can also be applied to phenols other than phenol or aromatic amines means that peroxidase can react with these substance groups. This can be easily inferred from the fact that it can be used as a reaction substrate.

On the other hand, the literature mentioned in the prior art section, Science (5
Science) Magazine, Volume 224, No. 4607, 2
59-261 (1983) is extrapolated to an aqueous phenol solution with a concentration of 10 g/β, the amount of peroxidase required to remove 98% or more of phenol is 1β
per 200.000 purpurogalin units, hydrogen peroxide is 0.2 m01. In actual experiments, we found that adding the entire required amount of hydrogen peroxide at the start of the reaction resulted in a
The amount of peroxidase required to remove 98% of phenol from a 9/β aqueous phenol solution was 150,000 purpurogalin units per 12 aqueous solution. Further, the required amount of hydrogen peroxide was 0.2 mol.

From the above, according to the method of the present invention, the amount of peroxidase required to remove 98% of phenol from a 109/I phenol aqueous solution is 1/30th that of the conventional method. The required amount of hydrogen is 60
It can be seen that it is about %.

[Effects of the Invention] As explained above, according to the method of the present invention, when removing phenols etc. from an aqueous solution, the amount of peroxidase used as a catalyst can be greatly reduced compared to the conventional method, and the amount of peroxidase can be greatly reduced compared to the conventional method. The amount of hydrogen can also be reduced. Therefore, the cost required for removal is reduced, which is very advantageous from a practical point of view.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing changes over time in phenol: degree a in an aqueous phenol solution.

Claims (1)

[Claims] (1) A method for removing phenols and/or aromatic amines in an aqueous solution by reacting them with hydrogen peroxide in the presence of peroxidase, while always maintaining the hydrogen peroxide concentration in the aqueous solution at 10 mmol/l or less. 1. A method for removing phenols and aromatic amines from an aqueous solution, characterized by carrying out a reaction.