JP2020006364A - Aldehyde-containing water treatment agent - Google Patents

Abstract

To provide an aldehyde-containing water-treating agent that quickly and persistently scavenges aldehydes.SOLUTION: An aldehyde-containing water-treating agent is used which comprises one or more selected from O-substituted hydroxylamine derivatives represented by the general formula (1) in the figure and chemically acceptable salts thereof. (In the formula, R represents a hydrogen atom or C1-4 alkyl group; n represents an integer from 1 to 6; and multiple occurrences of R may be identical or different.)SELECTED DRAWING: None

Description

  The present invention relates to a treatment agent for removing aldehydes from water containing aldehydes discharged from various factories and research facilities.

  Aldehydes, especially lower aldehydes, are harmful substances that are suspected of carcinogenicity, and therefore, methods for treating aldehyde-containing wastewater discharged from factories and research facilities have been studied for some time.

  Known methods for removing aldehydes in wastewater include, for example, a method of decarboxylating or reducing aldehydes using a platinum group metal catalyst such as ruthenium (see, for example, Patent Documents 1 and 2). However, the method for removing aldehyde using a metal catalyst requires an expensive catalyst and high-temperature reaction conditions of 100 ° C. or higher, and thus has a problem in running cost.

  Further, as a method for removing organic substances in wastewater, a method using an adsorbent such as activated carbon is known (for example, see Patent Document 3). This is a method of removing organic substances efficiently by flowing organic substance-containing wastewater through the adsorbent. However, the wastewater treatment method using an adsorbent has a problem in that the aldehyde-containing wastewater cannot be efficiently treated because the ability to adsorb to a low molecular weight and low boiling point organic substance such as a lower aldehyde is low.

JP-A-7-232178 JP-A-8-192174 JP-A-9-77508

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a method for rapidly and highly treating aldehydes in aldehyde-containing water without using a treatment condition having a large running cost or a treatment condition using an adsorbent.

  The present inventors have found that a treating agent containing a specific O-substituted hydroxylamine or a chemically acceptable salt thereof rapidly and continuously captures aldehydes in aldehyde-containing water, and has completed the present invention. I came to.

That is, the present invention has the following gist.
[1]
An aldehyde-containing water treating agent comprising at least one O-substituted hydroxylamine derivative represented by the following general formula (1) or a chemically acceptable salt thereof.

(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N represents an integer of 1 to 6. A plurality of Rs may be the same or different.)
[2]
In the O-substituted hydroxylamine derivative represented by the general formula (1), R is a hydrogen atom and n is an integer of 1 to 4, or a chemically acceptable salt thereof. The aldehyde-containing water treating agent according to [1], which comprises at least one species.
[3]
A method for treating aldehyde-containing water, comprising using the treating agent according to [1] or [2].

  The treating agent of the present invention quickly and continuously captures aldehydes. As a result, aldehydes harmful to the human body can be reduced and the living environment of humans can be improved.

  The treating agent of the present invention is characterized in that it contains one or more specific O-substituted hydroxylamine derivatives or chemically acceptable salts thereof.

  In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopropyl group, a butyl group and an isobutyl group. , Sec-butyl group, tert-butyl group, cyclobutyl group and the like. n represents an integer of 1 to 6. R is preferably a hydrogen atom, and n is preferably an integer of 1 to 4 from the viewpoint of high aldehyde scavenging ability.

  The O-substituted hydroxylamine (1) may be partially or entirely a chemically acceptable salt with an inorganic acid or an organic acid. The type of the salt is not particularly limited, but includes, for example, hydrochloride, hydrobromide, perchlorate, silicate, tetrafluoroborate, hexafluorophosphate, sulfate, nitrate, phosphoric acid Inorganic salts such as salts, acetates, citrates, fumarates, maleates, trifluoromethanesulfonates, trifluoroacetates, benzoates, and organic acid salts such as p-toluenesulfonate. Inorganic acid salts are preferred because they are inexpensive, and hydrochlorides are more preferred.

  Since the O-substituted hydroxylamine (1) has a carboxy group in the molecule, the carboxy group may form an internal salt with an alkoxyamino group in the molecule. Further, a part or all of the carboxy group may be a carboxylate. The type of the carboxylate is not particularly limited, and examples thereof include an alkali metal salt such as a lithium salt, a sodium salt, a potassium salt, and a cesium salt, and an ammonium salt.

  Although the O-substituted hydroxylamine (1) or a chemically acceptable salt thereof used in the treating agent of the present invention is partially commercially available, it is prepared according to the method described in Patent Document (JP-A-5-86012). be able to.

  The treating agent of the present invention can be used in any form depending on the purpose and application. For example, an O-substituted hydroxylamine or a chemically acceptable salt thereof (hereinafter referred to as “O-substituted hydroxylamines”) itself or an aqueous solution thereof is directly used as the aldehyde-containing water, or the O-substituted hydroxylamine is used. Can be supported on any carrier and used as a solid processing agent.

  In preparing the solid processing agent, any carrier that supports O-substituted hydroxylamines can be used without particular limitation as long as it is insoluble in water. For example, as a polymer carrier, styrene-based polymers such as polystyrene and cross-linked polystyrene, polyolefins such as polyethylene and polypropylene, poly (halogenated olefins) such as polyvinyl chloride and polytetrafluoroethylene, and nitrile-based polymers such as polyacrylonitrile, (Meth) acrylic polymers such as methyl methacrylate and polyethyl acrylate; and high molecular weight polysaccharides such as cellulose, agarose and dextran; and inorganic carriers such as activated carbon, silica gel, diatomaceous earth, hydroxyapatite, alumina and titanium oxide. , Magnesia, polysiloxane and the like.

  Here, crosslinked polystyrene refers to monovinyl aromatic compounds such as styrene, vinyltoluene, vinylxylene and vinylnaphthalene and divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene, trivinylbenzene, bisvinyldiphenyl, bisvinylphenylethane, etc. And a methacrylic acid ester such as glycerol methacrylate or ethylene glycol dimethacrylate may be copolymerized with these copolymers.

  The shape of the carrier is not particularly limited, and examples thereof include spherical (eg, spherical particles), granular, fibrous, granular, monolithic columns, hollow fibers, and membranes (eg, flat membranes). A shape generally used as a separation substrate can be used, and among these, a spherical, membrane-like, granular, granular, or fibrous shape is preferable. Spherical, granular, or granular carriers are particularly preferably used, when used in a column method or a batch method, since the used volume can be freely set.

  As the particle size of the spherical, granular, or granular carrier, those having an average particle diameter in the range of 1 μm to 10 mm can be used, but preferably 2 μm to 1 mm.

  The carrier may be porous or non-porous. As the average pore diameter of the porous carrier, usually, a pore diameter of 1 nm to 1 μm can be used, but a range of 1 nm to 300 nm is preferable in terms of an aldehyde trapping speed.

  The method for preparing the solid processing agent is not particularly limited, and includes, for example, a method in which O-substituted hydroxylamines are physically adsorbed on a carrier and immobilized.

  The method for immobilizing the O-substituted hydroxylamines by physically adsorbing them is not particularly limited. For example, the O-substituted hydroxylamines are dissolved in a solvent such as water, and then the above-mentioned carrier is added thereto. -A method of impregnating the carrier with substituted hydroxylamines and further distilling off the solvent.

  The loading amount of the O-substituted hydroxylamines on the carrier can be arbitrarily adjusted according to the purpose and is not particularly limited, but the O-substituted hydroxylamines are preferably in a range of 1 to 50% by weight, The range of 5 to 30% by weight is more preferable.

  The method of using the treating agent of the present invention is not particularly limited, but the O-substituted hydroxylamine itself, its aqueous solution, or its solid treating agent is added to or mixed with water containing aldehydes. Thereby, a method of capturing aldehydes can be mentioned.

  Hereinafter, the present invention will be specifically described, but the present invention should not be construed as being limited to these examples.

Example 1
(Aminooxy) acetic acid (0.25 mmol) was dissolved in water (5 mL) to prepare an aldehyde scavenger. Here, 5 mL of an aqueous solution containing acetaldehyde (0.25 mmol) was added and mixed. Five minutes later, a part (0.2 mL) of the reaction solution was extracted, 2 mg of sodium borohydride was added thereto, the remaining acetaldehyde was reduced to ethanol, and diglyme was further added as an internal standard substance. This solution was analyzed by gas chromatography (GC-2014, manufactured by Shimadzu Corporation), and the amount of residual acetaldehyde was calculated from the area ratio between ethanol and diglyme. Furthermore, as a result of calculating the aldehyde trapping rate using the following formula, the aldehyde trapping rate was 99%.

  Aldehyde capture rate (%) = [(initial concentration of acetaldehyde−remaining acetaldehyde concentration) ÷ initial concentration of acetaldehyde] × 100.

Example 2
(Aminoxy) acetic acid (0.50 mmol) was dissolved in water (5 mL) to prepare an aldehyde scavenger. Here, 5 mL of an aqueous solution containing formaldehyde (0.50 mmol) was added and mixed. Five minutes later, a part (0.2 mL) of the reaction solution was extracted, 2 mg of sodium borohydride was added thereto, the remaining formaldehyde was reduced to methanol, and diglyme was further added as an internal standard substance. This solution was analyzed with a gas chromatograph (GC-2014, manufactured by Shimadzu Corporation), and the amount of residual formaldehyde was calculated from the area ratio of methanol to diglyme. Further, as a result of calculating the aldehyde trapping rate using the following formula, the aldehyde trapping rate was 99%.

  Aldehyde scavenging rate (%) = [(formaldehyde initial concentration−remaining formaldehyde concentration) ÷ formaldehyde initial concentration] × 100.

Example 3
As a result of carrying out in the same manner as in Example 1 except that the treatment time was set to 24 hours, the aldehyde scavenging rate was 99.9%, and the treating agent of the present invention maintained high aldehyde scavenging performance even after a long period of time.

Example 4
As a result of carrying out in the same manner as in Example 2 except that the treatment time was set to 24 hours, the aldehyde scavenging rate was 99.9%, and the treating agent of the present invention maintained high aldehyde scavenging performance even after a long time had passed.

Comparative Example 1
As a result of carrying out in the same manner as in Example 1 except that 0.1 g of activated carbon was used instead of (aminooxy) acetic acid, the aldehyde trapping ratio was 48%.

Comparative Example 2
As a result of performing the same operation as in Example 2 except that 0.1 g of activated carbon was used instead of (aminooxy) acetic acid, the aldehyde trapping ratio was 6%.

  The treating agent of the present invention quickly and continuously captures aldehydes in water. As a result, aldehydes harmful to the human body can be reduced and the living environment of humans can be improved.

Claims (3)

An aldehyde-containing water treating agent comprising at least one O-substituted hydroxylamine derivative represented by the following general formula (1) or a chemically acceptable salt thereof.
(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N represents an integer of 1 to 6. A plurality of Rs may be the same or different.)   In the O-substituted hydroxylamine derivative represented by the general formula (1), R is a hydrogen atom, and n is an integer of 1 to 4, or a chemically acceptable salt thereof. The aldehyde-containing water treating agent according to claim 1, comprising at least one species.   A method for treating aldehyde-containing water, comprising using the treatment agent according to claim 1.