JPH0464757B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a metal scavenger.

[Conventional technology]

In recent years, as the pollution of rivers, oceans, etc. by wastewater from factories has become a problem, regulations to prevent pollution by wastewater have been strengthened, and it is now mandatory to keep metals contained in wastewater below a specified concentration. Ori,
Particularly strict regulations are in place for heavy metals that are harmful to the human body, such as mercury, cadmium, zinc, lead, copper, and chromium. For this reason, various methods have been proposed to remove metals from wastewater, including ion flotation, ion exchange, electrolytic flotation, electrodialysis, reverse osmosis, slaked lime, A known method is a neutralization coagulation-sedimentation method, in which metals are turned into hydroxides by adding an alkaline neutralizing agent such as caustic soda, and then removed by coagulation and precipitation using a polymer flocculant. A method of collecting and removing metals using a metal scavenger is also known, and a metal scavenger containing aliphatic polydithiocarbamic acid or its salts is known as this type of metal scavenger. (Japanese Patent Publication No. 49-99978).

[Problem that the invention seeks to solve]

However, ion flotation method, ion exchange method,
The electrolytic flotation method, electrodialysis method, and reverse osmosis method have problems with the removal rate of heavy metals, operability, running costs, etc., and are currently only used for some special wastewater treatments. In addition, the neutralization coagulation precipitation method generates a large amount of metal hydroxide sludge, and these hydroxide sludges have problems such as poor dewatering properties and large sludge volumes, making it difficult to transport. It is also very difficult to remove it below the standard value. Moreover, depending on how these sludge is disposed of, there is also the problem that it may re-melt and cause secondary pollution.

On the other hand, although the above problems can be solved by a method of collecting and removing metals using a metal scavenger containing aliphatic polydithiocarbamic acid or its salts, the molecular weight of this metal scavenger is small. Therefore, it is necessary to add a large amount, and the floc produced is small, resulting in problems such as poor sedimentation properties.

[Means for solving problems]

As a result of intensive research in view of the above points, the present inventors have found that at least one carbodithioic acid group and/or its salts are substituted with the active hydrogen atom of a polycondensed polyamine obtained by polycondensation of polyamines and epihalohydrin. The present inventors have discovered that the compound has excellent performance as a metal scavenger, and have completed the present invention.

That is, the present invention provides a metal scavenger characterized by having as a substituent at least one carbodithio acid group and/or a salt thereof substituted with an active hydrogen atom of a polycondensed polyamine obtained by polycondensation of a polyamine and an epihalohydrin. This is the summary.

The metal scavenger of the present invention is a compound having a structure having at least one carbodithioic acid group (-CSSH) and/or its salts as a substituent substituted with the active hydrogen atom of a polycondensed polyamine, and as described below and epihalohydrin are polycondensed to form a polycondensed polyamine, and then a carbodithio acid group or its salts are introduced as a substituent into the polycondensed polyamine, or a carbodithio acid group or its salts are introduced into polyamines as a substituent. After that, it is obtained by a method of polycondensation with epihalohydrin.

Further, in the metal scavenger of the present invention, one or more types of an alkyl group, a hydroxyalkyl group, and an acyl group may be bonded to the nitrogen atom of the polycondensed polyamine as an N-substituent. The above-mentioned N-substituents are used to convert polyamines into alkyl halides such as methyl halide, ethyl halide, butyl halide, lauryl halide, stearyl halide, etc. before polycondensation with epihalohydrin; ethylene oxide, propylene oxide, butylene oxide, styrene oxide, 1,2- Dodecyl epoxy alkane, 1,2
- Epoxy alkanes such as octacosyl epoxy alkanes, fatty acids such as acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, or esters of these fatty acids; React with acid halides of fatty acids, or
It can be introduced by polycondensing polyamines and epihalohydrin to obtain a polycondensed polyamine, and then reacting it with the above-mentioned alkyl halides, epoxyalkanes, or fatty acids.
Also, the same type of N-substituent is present in the molecule.
There may be more than one, and two or more of different types may exist.

The metal scavenger of the present invention may have a structure in which a carbodithioic acid group and/or its salts are bonded to the nitrogen atom of a polycondensed polyamine. It may have a structure in which a carbodithioic acid group and/or its salt is bonded to an oxygen atom in substitution for a hydrogen atom, or it may have a structure in which it is bonded to both a nitrogen atom and an oxygen atom. Examples of the salts of the carbodithioic acid group include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, and ammonium salts.

The above polyamines have 1 or 2 atoms per nitrogen atom.
A compound having two or more imino or amino groups formed by bonding active hydrogen atoms, such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetramine. , polyalkylene polyamines such as tripropylenetetramine, tributylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, tetrabutylenepentamine, pentaethylenehexamine; phenylenediamine, xylenediamine,
meta-xylene diamine, iminobispropylamine, monomethylaminopropylamine, methyliminobispropylamine, 1,3-bis(aminomethyl)cyclohexane, 1,3-diaminopropane, 1,4-diaminobutane, 3,5-diamino Examples include chlorobenzene, melamine, 1-aminoethylpiperazine, piperazine, diaminophenyl ether, 3,3'-dichlorobenzidine, tolidine base, m-tolylenediamine, and polyethylene polyimine (average molecular weight 300 or more). In addition to the above polyamines, it is also possible to use N-alkyl polyamines, N-hydroxyalkyl polyamines, N-acyl polyamines, etc. obtained by reacting these polyamines with alkyl halides, epoxy alkanes, or fatty acids. . As the N-alkyl polyamine, N-alkylethylenediamine, N-
Alkylpropylene diamine, N-alkylhexamethylene diamine, N-alkylphenylene diamine, N-alkylxylene diamine, N-alkyldiethylenetriamine, N-alkyltriethylenetetramine, N-alkyltetraethylenepentamine, N-alkylpentaethylenehexamine etc. can be used. The N-substituted alkyl group preferably has 2 to 18 carbon atoms. Examples of N-hydroxyalkylpolyamines include N-hydroxyethylpolyamine, N-hydroxypropylpolyamine, N-hydroxybutylpolyamine, and N-hydroxybutylpolyamine.
-β-hydroxydodecylpolyamine, N-β-
Examples include hydroxytetradecylpolyamine, N-β-hydroxyhexadecylpolyamine, N-β-hydroxyoctadecylpolyamine, N-β-hydroxyoctacosylpolyamine, and the like. In addition, N-acylpolyamines include N-acetylpolyamine, N-propionylpolyamine, N-
Butyl polyamine, N-caproyl polyamine,
Examples include N-lauroylpolyamine, N-oleoylpolyamine, N-myristyroylpolyamine, N-stearoylpolyamine, and N-beheroylpolyamine. These polyamines can be used alone or in combination of two or more. Also, epihalohydrin is epichlorohydrin,
Examples include epibromohydrin, epiiodohydrin, and the like.

The metal scavenger of the present invention is a polyamine that is polycondensed with epihalohydrin (in the case where a substituent is introduced into the polyamine before polycondensation with epihalohydrin, the polyamine before the introduction of the substituent) is a diamine having two amino groups. In some cases, it has a linear structure and is generally water-soluble. Further, when it has a crosslinked structure, it becomes dispersible or suspendable in water.

Next, the method for producing the metal scavenger of the present invention will be specifically explained.

The first method for producing the metal scavenger of the present invention is to polycondensate polyamines and epihalohydrin to obtain a polycondensed polyamine, and then introduce a carbodithioic acid group by acting carbon disulfide on the polycondensed polyamine. It's a method. In this method, amines and epihalohydrin are first polycondensed to obtain a polycondensed polyamine. After the epihalohydrin is added dropwise to the amine while heating and stirring, the polycondensed polyamine is prepared for 1 to 20 hours, preferably 1 to 6 hours. Obtained by heating. The heating temperature of the amine when dropping epihalohydrin is 10 to 100°C, preferably 30 to 90°C, and the heating temperature after epihalohydrin is dropped is 10 to 150°C, preferably 30 to 90°C.
It is 100℃. Next, the polycondensed polyamine and carbon disulfide are heated in a solvent at 10 to 100°C in the presence of an alkali.
By heating for 1 to 20 hours, preferably at 30 to 60°C for 1 to 8 hours, carbodithioic acid groups and/or their bases are introduced into the polycondensed polyamine, thereby obtaining the metal scavenger of the present invention. The above alkalis include lithium hydroxide, potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide,
Ammonium hydroxide etc. are used. Also, as a solvent, water, methanol, acetone, dioxane,
Toluene, dimethylformamide, etc. are used, and water, acetone, and dioxane are particularly preferred.

The second method for producing the metal scavenger of the present invention is
This method involves reacting polyamines with carbon disulfide to produce a polyamine derivative having a carbodithioic acid group and/or its base, and then polycondensing this polyamine derivative with epihalohydrin. The reaction between polyamines and carbon disulfide is carried out by reacting polyamines and carbon disulfide in the presence of an alkali.
~100℃ for 1 to 20 hours, preferably 30 to 60℃ for 1 hour
This is done by heating for ~5 hours. As the alkali for reacting polyamines with carbon disulfide, the same alkali as used in the first method is used. The above reaction may be carried out in a solvent if necessary, and the same solvents used in the first method may be used, but water, acetone, and dioxane are particularly preferred. Next, the polyamine derivative into which the carbodithioic acid group and/or its salts have been introduced is polycondensed with epihalohydrin, and this reaction is carried out at a temperature of 10 to 100°C, preferably at 30°C.
After heating to ~90°C and adding epihalohydrin dropwise under stirring, at 10-150°C for 1-20 hours, preferably
This is carried out by holding at 30-100°C for 1-6 hours.

The metal scavenger of the present invention having a carbodithioic acid group and/or its salt as a substituent can be obtained as described above. The alkaline earth of carbodithioic acid is treated with a water-soluble alkaline earth metal salt such as calcium or magnesium hydroxide or calcium or magnesium chloride, nitrate, or sulfate to replace the alkaline earth metal. A metal scavenger having a similar metal salt as a substituent can also be used.

According to the metal collector of the present invention, metals such as mercury, cadmium, zinc, lead, copper, chromium, arsenic, gold, silver, platinum, vanadium, and thallium can be efficiently collected and removed.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 261.1 g of metaxylene diamine and a water-acetone (1:1) mixture were placed in a four-necked flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser.
300g was added and heated to 60°C with stirring, and 174g of epichlorohydrin was added dropwise over 4 hours while controlling the temperature so as not to exceed 90°C. After the dropwise addition was completed, it was held at 80 to 90°C for 1 hour. 727 g of a water-acetone solution of a polycondensed polyamine obtained by polycondensing meta-xylene diamine and epichlorohydrin was obtained.

Next, 234.1 g of the polycondensed polyamine solution, 517.4 g of pure water, and 59.9 g of sodium hydroxide were placed in the same apparatus as above, and 86.9 g of carbon disulfide was added dropwise over 3 hours while stirring at 40°C. After further holding at the same temperature for 1 hour, water-acetone was distilled off at 60 to 90°C, and 305 g of water was added to obtain an aqueous solution of the reaction product (metal scavenger). The viscosity of the aqueous solution of this reaction product was 84 mPa·s (25°C), and the concentration of the metal scavenger was 27.2%.

Next, aqueous solution 1 containing 100mg/Cu ²⁺
To this, an aqueous solution of the above metal collector was added so that the amount of the metal collector was 40 mg, 85 mg, 125 mg, and 165 mg, and the mixture was stirred for 10 minutes until the copper was collected by the metal collector. When the precipitates formed were separated and the concentration of Cu ²⁺ remaining in the solution was measured, each was found to be 60
mg/, 28 mg/, 13 mg/, and 0.05 mg/. From this result, the amount of Cu ²⁺ captured by this metal scavenger was determined to be 300 mg-Cu/g (per 1 g of metal scavenger). Also 100 as Hg ²⁺
An experiment similar to the above copper-containing aqueous solution was conducted using an aqueous solution containing ^1,172 mg-Hg/
It was hot at g.

Example 2 Ethylenediamine was placed in an apparatus similar to Example 1.
30.6 g, pure water 450 g, and potassium hydroxide 57.2 g were added, and 77.5 g of carbon disulfide was added dropwise at 50°C over 4 hours, and then heated at 60°C for 3 hours to form a solution containing potassium carbodithioate base as a substituent. An ethylenediamine derivative was obtained. Next, the mixture was cooled to 30°C, and 47.2 g of epichlorohydrin was added dropwise thereto over 5 hours, and the reaction was continued at 70 to 90°C for 3 hours. 308 g of pure water was added to the obtained reaction product to obtain a 20% aqueous solution of metal scavenger. The viscosity of this aqueous solution is 32m
The temperature was Pa·s (25°C).

Using this aqueous solution of metal scavenger, the same copper-containing aqueous solution and mercury-containing aqueous solution as in Example 1 were treated in the same manner, and the results showed that Cu ²⁺ and
When the amount of Hg ²⁺ collected was determined, it was 168 mg−
Cu/g and 637 mg-Hg/g.

Example 3 In a 500 ml four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, 71.2 g of metaxylene diamine and 279 g of a 7.5% aqueous sodium hydroxide solution were added.
79.6 g of carbon disulfide was added dropwise over 6 hours at 45°C with vigorous stirring. After the dropwise addition, the reaction was carried out at the same temperature for 1.5 hours, and then at 70°C for 2 hours. An aqueous solution of a reaction product having an acid group and a sodium carbodithioate base as a substituent was obtained.

Put 400g of the above aqueous solution and 267.3g of pure water into the same device as above, and heat 50.3g of epichlorohydrin at 60℃.
was added over a period of 4 hours, and the reaction was further carried out at 70 to 80°C for 1 hour to obtain an aqueous solution of a metal scavenger.

The resulting aqueous solution of metal scavenger contained 28.1% metal scavenger. Further, the viscosity of this metal scavenger aqueous solution was 73 mPa·s (25°C).

A copper-containing aqueous solution and a mercury-containing aqueous solution were treated using the aqueous solution of the above metal scavenger in the same manner as in Example 1, and the amounts of Cu ²⁺ and Hg ²⁺ captured by this metal scavenger were determined. However, 300mg-Cu/g, respectively.
It was 1143 mg-Hg/g.

Example 4 Diethylenetriamine was added to the same apparatus as in Example 3.
21.0g, pure water 326.4g and sodium hydroxide 24.5g
g, and 46.5 g of carbon disulfide was added dropwise at 40° C. over 3 hours. After the dropwise addition was completed, the reaction was further carried out at 70°C, and then cooled to approximately 30°C and epibromohydrin 34.4
g was added over 2 hours, the temperature was raised to 80 to 90°C, and the reaction was continued for 2 hours to obtain an aqueous solution containing 27.1% of the metal scavenger. The viscosity of this aqueous solution is 58m
The temperature was Pa·s (25°C).

A copper-containing aqueous solution and a mercury-containing aqueous solution were treated using the aqueous solution of the metal scavenger in the same manner as in Example 1, and the results showed that Cu ²⁺ in the metal scavenger,
When the amount of Hg ²⁺ collected was determined, it was 169 mg−
Cu/g and 651 mg-Hg/g.

Example 5 Diethylenetriamine was added to the same apparatus as in Example 1.
29.9 g and 120 g of toluene were added thereto, and 26.8 g of epichlorohydrin was added dropwise over 3 hours at 40 to 50°C. After the dropwise addition was completed, the reaction was continued at 60°C for 2 hours. Next, add 46.4g of sodium hydroxide and pure water to this.
Add 641.8g of carbon disulfide to 66.1g of carbon disulfide at 40℃.
The mixture was added dropwise over a period of time, and after the completion of the addition, the reaction was further carried out at 70°C for 4 hours. After the reaction was completed, the mixture was cooled to 30° C., stirring was stopped, and the mixture was separated into two layers. After removing the toluene in the upper layer, it was heated to 40°C with stirring, and 48.9 g of bromomethyloxirane was added dropwise over 3 hours. After the dropwise addition, the reaction was continued at 70 to 80°C for 1 hour to form an aqueous solution of the metal scavenger. I got it. The resulting aqueous solution contained 22.6% metal scavenger. The viscosity of this aqueous solution is
It was 32mPa・s (25℃).

Using the aqueous solution of the metal scavenger, the aqueous solution was treated in the same manner as in Example 1 to remove Cu ²⁺ and
When the amount of Hg ²⁺ collected was determined, it was 145 mg−
Cu/g, 546 mg-Hg/g hot.

Example 6 Diethylenetriamine was added to the same apparatus as in Example 1.
31.1g was added, and 123.2g of epoxyalkane (alkyl group has 28 carbon atoms) was added dropwise at 90℃ over 30 minutes.
After the dropwise addition, the reaction was further carried out at the same temperature for 2 hours, and N
-Hydroxyalkyldiethylenetriamine was obtained. Next, it was cooled to 40℃, and 667.7g of pure water was added to it.
After adding 24.2 g of sodium hydroxide, 45.9 g of carbon disulfide was added dropwise over 2 hours.
The reaction was continued for 3 hours at ℃. After the reaction is completed, 80-90
27.9 g of epichlorohydrin was added dropwise over 3 hours at a temperature of 0.degree. C., and after the addition was completed, the reaction was continued at 90 to 100.degree. C. for an additional 3 hours.

Add pure water to the reaction product obtained as above.
260.9g was added to obtain an aqueous solution containing 20.0% metal scavenger. The viscosity of this aqueous solution is 45 mPa・s (25
℃).

A copper-containing aqueous solution and a mercury-containing aqueous solution were treated using the above aqueous solution in the same manner as in Example 1, and the amounts of Cu ²⁺ and Hg ²⁺ captured by the metal collector were determined.
They were 80 mg-Cu/g and 302 mg-Hg/g, respectively.

Example 7 62.7 g of N,N′′′′-bis(hydroxyethyl)triethylenetetramine was placed in the same apparatus as in Example 3, and 24.8 g of epichlorohydrin was added at 50°C.
The mixture was added dropwise over a period of time, and after the completion of the addition, the reaction was continued for an additional 2 hours at 80-90°C. Next, 672.7 g of 8% sodium hydroxide aqueous solution was added to this, and 81.5 g of carbon disulfide was added dropwise at 50°C over 2 hours.
The temperature was raised to ℃, the reaction was continued for 3 hours, and the metal scavenger was removed.
An aqueous solution containing 22.3% was obtained. The viscosity of this aqueous solution was 48 mPa·s (25°C).

The aqueous solution containing the above metal scavenger was treated in the same manner as in Example 1, and the amounts of Cu ²⁺ and Hg ²⁺ captured by the metal scavenger were determined to be 177 mg-Cu, respectively. /g, 666 mg-Hg/g.

Example 8 22.4 g of polyethyleneimine (average molecular weight 70,000) and 933.2 g of a 1.1% aqueous sodium hydroxide solution were placed in the same apparatus as in Example 1, and 19.7 g of carbon disulfide was added dropwise at 50°C over 1 hour. After completion of the reaction, the reaction was continued for an additional 2 hours at the same temperature. Next, 0.5 g of epichlorohydrin was added dropwise over 3 hours, and then 80 g of
The reaction continued at ℃ for 2 hours. The resulting reaction product had a viscosity of 28 mPa·s (25°C) and contained 5% metal scavenger.

The aqueous solution containing the above metal scavenger was treated in the same manner as in Example 1, and the amount of Cu ²⁺ and Hg ²⁺ captured by the metal scavenger was determined to be 214 mg-Cu. /g, and 821 mg-Hg/g.

Example 9 42.5 g of N-methyldiethylenetriamine and 50 g of a water-dioxane (2:1) mixture were placed in the same apparatus as in Example 3, and 33.6 g of epichlorohydrin was added to 70 g of a mixture of water and dioxane (2:1).
Start dropping at a temperature of 95°C, continue dropping for 4 hours while adjusting the temperature so as not to exceed 95°C.
The reaction continued for 2 hours at ~95°C. Next, the mixture was cooled to 40°C, 230g of pure water and 43.6g of sodium hydroxide were added, and 55.3g of carbon disulfide was added dropwise over 3 hours. After the dropwise addition, topping was continued at 70°C under reduced pressure until dioxane was no longer detected. After going, 120g of pure water
was added to obtain an aqueous solution of a metal scavenger. The metal scavenger concentration in the obtained aqueous solution was 22.5%, and the viscosity of this aqueous solution was 31 mPa·s (25°C).

The aqueous solution containing the above metal scavenger was treated in the same manner as in Example 1, and the amount of Cu ²⁺ and Hg ²⁺ captured by the metal scavenger was determined to be 157 mg-Cu. /g, and 594 mg-Hg/g.

Example 10 In a device similar to Example 1, 64 g of N-methylethylenediamine, 619.9 g of pure water, and sodium hydroxide were added.
34.6 g of carbon disulfide was added thereto, and 65.7 g of carbon disulfide was added dropwise thereto at 50°C over 3 hours, and after the dropwise addition was completed, the reaction was continued at 70°C for an additional 2 hours. After the reaction was completed, the mixture was cooled to 30° C., 79.9 g of epichlorohydrin was added dropwise at 70° C. over 3 hours, and the reaction was further continued at the same temperature for 3 hours to obtain an aqueous solution of a metal scavenger.

The metal scavenger concentration in the resulting aqueous solution was 26.5%, and the viscosity of the aqueous solution was 88 mPa·s (25°C).

The aqueous solution containing the above metal scavenger was treated in the same manner as in Example 1, and the amount of Cu ²⁺ and Hg ²⁺ captured by the metal scavenger was determined to be 130 mg-Cu. /g, and 430 mg-Hg/g.

Comparative Example 1 30.6 g of ethylenediamine, 450 g of pure water and 57.2 g of potassium hydroxide were placed in the same apparatus as in Example 1, and 77.5 g of carbon disulfide was added under the same conditions as in Example 2.
g was added and reacted to obtain a reaction product. The viscosity of the aqueous solution made by adding water to make it 20% is 4m.
The temperature was Pa·s (25°C).

Using the above aqueous solution, the same aqueous solution as in Example 1 was treated and the amount of collected Cu ²⁺ and Hg ²⁺ was determined.
They were 108 mg-Cu/g and 403 mg-Hg/g, respectively.

Comparative Example 2 50.9 g of pentaethylenehexamine, 300 g of pure water, and sodium hydroxide were placed in the same apparatus as in Example 1.
52.7 g of carbon disulfide was added and reacted under the same conditions as in Example 2 to obtain a reaction product.
The viscosity of an aqueous solution made by adding water to a 20% concentration was 6 mPa·s (25°C).

Using the above aqueous solution, the same aqueous solution as in Example 1 was treated and the amount of collected Cu ²⁺ and Hg ²⁺ was determined.
They were 298 mg-Cu/g and 1068 mg-Hg/g, respectively.

〔Effect of the invention〕

As explained above, the metal scavenger of the present invention has at least one carbodithioic acid group substituted with the active hydrogen of a polycondensed polyamine obtained by polycondensation of a polyamine and an epihalohydrin and/or a salt thereof bonded as a substituent. Due to this structure, metal adsorption treatment can be sufficiently performed with a smaller amount added than conventional metal scavengers containing aliphatic polydithiocarbamic acids or salts thereof. Furthermore, since the metal collecting agent of the present invention has large flocs produced by collecting metals, the sedimentation speed of the flocs is fast, and therefore metals in wastewater can be quickly collected and removed. has.

Claims (1)

[Scope of Claims] 1. A metal trap characterized by having as a substituent at least one carbodithioic acid group and/or a salt thereof substituted with an active hydrogen atom of a polycondensed polyamine obtained by polycondensation of a polyamine and an epihalohydrin. Collection drug. 2 N- bonded to the nitrogen atom of the polycondensed polyamine
The metal scavenger according to claim 1, which has at least one kind selected from the group consisting of an alkyl group, a hydroxyalkyl group, and an acyl group as a substituent.