JPS6265788A - Method for capturing metal - Google Patents

Abstract

PURPOSE:To efficiently and surely capture metallic ions in waste water by making combination use of a polyamine deriv. and at least one kind of Na monosulfide, Na polysulfide and Na hydrogensulfide. CONSTITUTION:The polyamine deriv. having at least one dithiocarboxylic group or the salt thereof as an N-substituent in one molecule and at least one kind of Na monosulfide, Na polysulfide and Na hydrogensulfide are used in combination as a metal capturing agent. The using ratio of the polyamine deriv. and Na sulfides is preferably 1:99-99:1 by weight, more particularly preferably 20:80-98:2. The amt. of the polyamine deriv. and Na sulfides to be added to the waste water is preferably 0.7-4mol eqv., more particularly preferably 0.9-1.5mol equiv. by the content of the metallic ions in the waste water as the total amt. of both. The metallic ions in the waste water are efficiently captured and removed satisfactorily with the amt. of the metal capturing agent smaller than the amt. to be used in the conventional metal capturing method according to the above-mentioned method.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for collecting metals.

[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. Particularly strict regulations are in place for heavy metals that are harmful to the human body, such as mercury, cadmium, zinc, copper, and chromium. For this reason, various methods have been proposed to remove metals from wastewater.
This type of method includes ion flotation, ion exchange, electrolytic flotation, electrodialysis, reverse osmosis, or adding an alkali neutralizer such as slaked lime or caustic soda to convert metals into hydroxides. A neutralization coagulation-sedimentation method, in which particles are removed by coagulation and precipitation using a polymer flocculant, is known. Furthermore, it is also known to use a metal scavenger to make metal ions in wastewater insoluble and remove them by precipitation. A dithiocarbamic acid compound with a structure in which dithiocarboxylic groups in the throat are bonded (Japanese Patent Application Laid-Open No. 51-14036
0), a compound having a structure obtained by addition polymerization of a compound having two acryloyl groups and an amino acid having two hydrogen atoms bonded to a nitrogen atom (Japanese Patent Publication No. 10999/1983), etc. are known.

[Problem that the invention seeks to solve]

However, the ion flotation method, ion exchange method, electrolytic flotation method, electrodialysis method, and reverse osmosis method have problems such as the removal rate of heavy metals, operability, and running cost, and are only applicable to some special wastewater treatments. The current situation is that it is not being used. In addition, the neutralization coagulation-sedimentation method generates a large amount of metal hydroxide sludge, and these hydroxide sludges have poor dewatering properties and large sludge volumes, making it difficult to transport. It is also very difficult to remove wastewater below the minimum value. Moreover, depending on how these sludges are disposed of, they may be redissolved and cause secondary pollution. Furthermore, the metal collectors described in JP-A No. 51-140360 and JP-B No. 54-10999 had a problem with their binding strength with metal ions, and the removal rate of metal ions from wastewater was not sufficient. .

[Means for solving problems]

As a result of intensive research in view of the above points, the present inventors found that polyamine derivatives having a small number (one dithiocarboxy group or a salt thereof as an N-substituent) in one molecule, sodium monosulfide, sodium polysulfide, sulfide The present invention has been completed by discovering that metal ions in waste water can be most efficiently and reliably collected and removed by using it together with at least one type of sodium hydrogen.

The metal collection method of the present invention uses a polyamine derivative having at least one dithiocarboxy group or a salt thereof as an N-substituent in one molecule, and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide. This is a method of removing metal ions from wastewater by adding it to wastewater containing metal ions.

The polyamine derivative used in the present invention has at least one dithiocarboxymini- C3
It is a compound having 5H or its salts, such as alkali metal salts such as sulfur/lium salts and potassium salts, alkaline earth metal salts such as calcium salts, and ammonium salts. - Polyamine derivatives having at least one dithiocarboxy group as an N-substituent in the molecule can be obtained, for example, by reacting polyamines with carbon disulfide,
Furthermore, after the completion of the reaction, sodium hydroxide, potassium hydroxide,
The active hydrogen of the dithiocarboxy group can be replaced with an alkali metal, an alkaline earth metal, ammonium, etc. by treatment with an alkali such as ammonium hydroxide or by performing the above reaction in the presence of an alkali. The reaction between polyamines and carbon disulfide is carried out in a solvent, preferably water or alcohol, at 30 to 100°C for 1 to 10 hours, especially 4
Preferably, the reaction is carried out at 0-70'C for 2-5 hours.

Examples of the above polyamines include ethylenediamine,
Propylene diamine, butylene diamine, hexamethylene diamine', diethylene triamine, dipropylene triamine, diethylene triamine, 1 to 1
- polyalkylene polyamines such as ramin, tripropylenetetramine, tributylenetetramine, otraethylenepentamin, tetrapropylenepentamine, tetrapropylenebentamine, pentaethylenehexamine;
Aniline, phenylene diamine, xylene diamine, metaxylene diamine, iminobispropylamine, monomethylaminopropylamine, methyliminobispropylamine, 1,3-bis(aminomethyl)cyclohexane, 3,5-diaminochlorohenzene, melamine, 1-
Aminoedylpiperazine, piperazine, 3,3'-dichlorohenzidine, diaminophenyl ether, tolidine base, m-)-lylenediamine, etc. are used. Furthermore, N-substituted polyamines having alkyl groups, acyl groups, etc. as substituents, such as N-alkyl polyamines and N-acyl polyamines, can also be used. These N-substituted polyamines can be obtained by reacting the polyamines with al;)-ruhalides and fatty acids. Examples of N-alkylpolyamines include N-alkylethylenediamine, N-alkylpropylenediamine, N-alkylhexamethylenediamine, N-alkylphenylenediamine, N-alkyldi-1-silenediamine, N-alkyldiethylenetriamine, and N-alkyltriamine. Examples include ethylenetetramine, N-alkyltetraethylenopentamine, N-alkylpentaethylenehexamine, and the number of carbon atoms in the N-substituted alkyl group is preferably 2 to 18.

As the N-acylpolyamine, the acyl group has 3 to 3 carbon atoms.
0 is preferable, for example, N-acetyl polyamine,
Examples include N-propionylpolyamine, N-butyrylpolyamine, N-caproylpolyamine, N-lauroylpolyamine, N-oleoylpolyamine, N-myristyroylpolyamine, N-stearoylpolyamine, N-beheroylpolyamine, etc. . These polyamines are
They can be used alone or in a mixture of two or more.

In the method of the present invention, a polyamine derivative having at least one dithiocarboxy group as an N-substituent and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide are added to wastewater to remove metal ions from the wastewater. Especially when sodium polysulfide or sodium hydrogen sulfide is used, flocs have good sedimentation properties and efficient wastewater treatment can be performed. Polysulfide 1-
As the lithium, lithium disulfide, sodium trisulfide, thorium tetrasulfide, and sodium trisulfide are used. The purpose of the present invention can be achieved if the weight ratio of the polyamine derivative to the above-mentioned sodium sulfides is 1:99 to 99:1, but it is particularly preferably 20:80 to 98:2. The polyamine derivative and the sodium sulfides may be mixed in advance and added to the wastewater, or they may be added to the wastewater separately, but it is preferable to mix them in advance and add them to the wastewater. Incidentally, when adding them separately, the effect of removing metal ions is almost the same whether the polyamine derivative is added first and then the sodium sulfides are added, or the metal ion removal effect is added in the reverse order.

The polyamine fi jiji body used in the present invention can be used alone as a metal scavenger, but when used in combination with sodium sulfide, the flocs produced are even larger, the time required for floc sedimentation can be shortened, and the Metal ions can be collected and removed extremely efficiently. In addition, sulfur (hysodium) also has the ability to form complexes with metal ions, but when used alone, the flocs produced are extremely small, making it difficult to precipitate and remove the flocs. Only then can metal ions in wastewater be efficiently collected and removed.

This is thought to be due to the synergistic effect of the ability of polyamine derivatives to form a complex with metal ions and the ability of sodium sulfides to form a complex with metal ions. Therefore, the amount of polyamine derivatives and sodium sulfides added to wastewater is 0.7 of the amount of metal ions in wastewater as the total amount of both.
= 4 molar equivalents, '(An amount that is 0.9 to 1.5 molar equivalents to ¥ is preferable.

In the present invention, when collecting and removing metal ions in wastewater by adding polyamine derivatives and sodium sulfides to wastewater, it is preferable to adjust the pH of the wastewater to 3 to 10, particularly 4 to 9. The acid or alkali used to adjust the pH may be anything as long as it does not inhibit the formation of chlorofluorocarbons, but normally, the acid used is hydrochloric acid, sulfuric acid, nitric acid, etc., and the alkali is dithrium hydroxide, water, etc. Potassium oxide, calcium hydroxide, etc. are used.

According to the method of the present invention, mercury, cadmium, zinc, lead, copper,
Chromium, arsenic, gold, silver, platinum, vanadium, thallium, etc. can be efficiently collected and removed.

〔Example〕

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

Example 1 40 g of ethylenediamine and 536 g of a 20% aqueous sodium hydroxide solution were placed in a four-eye flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser. Carbon sulfide 203.7
g was added dropwise, and after completion of the addition, aging was performed at the same temperature for 4 hours. Next, the reaction solution was poured into a large amount of acetate to form a precipitate, and the precipitate was purified by reprecipitation three times in a water-acetone system, and then dried under reduced pressure to convert the sodium salt of the dithiocarboxy group into N- Sulfur content as a substituent: 55
．． 260 g of 8 wt % polyamine derivative powder was obtained.

5 sodium hydrogen sulfide to 100 g of this polyamine derivative
66■ of a mixture containing 0 g of copper ion-containing aqueous solution>(i
(Contains 50 ppm Cu 2*, pH = 5°0),
Cadmium ion-containing aqueous solution (containing 50 ppm C, l", pH = 5.0), mercury ion-containing aqueous solution (50 ppm C, l" content, pH = 5.0)
0 ppm [(contains g2°, pH = 5.0), aqueous solution containing lead ions (contains 50 ppm pb'', pH -
5,0) to 1000 ml each of the four types of aqueous solutions,
After stirring for 5 minutes, the mixture was allowed to stand and the time required for the generated flocs to settle was measured. The results are shown in Table 1. Next, after the generated flocs were filtered, the residual metal ion concentration in the filtrate was measured by atomic absorption spectrometry. The results and the volume of the generated flocs are also shown in Table 1.

Example 2 Triethylenetetramine 101 was added to the same apparatus as in Example 1.
g and 464 g of 20% sodium hydroxide aqueous solution,
Carbon disulfide 176.3 t: was reacted in the same manner as in Example 1, and then purified and dried to obtain a sulfur content of 44.8 having a sodium salt of a dithiocarboxy group as an N-substituent.
265 g of a polyamine derivative powder with a % weight loss was obtained.

75 thorium pentasulfide to 100 g of this polyamine derivative
62 mg of the mixture of 4 g as in Example 1.
Each of the seeds was added to 1000 ml of an aqueous solution containing metal ions, and the floc precipitation time, amount of floc, filtrate produced, and residual metal ions in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3 Diethylenetriamine 48,5 was added to the same apparatus as in Example 1.
The mixture was heated to 60°C, and 145.9 g of carbon disulfide was added dropwise from the dropping funnel. After the addition was completed, the mixture was aged at the same temperature for 4 hours. The reaction solution was then heated to 70-75°C and 20% sodium hydroxide
4 g was added and the reaction was carried out for 165 hours. Thereafter, purification and drying was performed in the same manner as in Example 1 to obtain 179.8 g of a polyamine derivative powder having a sulfur content of 50.3 wt % and having a sodium salt of a dithiocarboxy group as an N-substituent.

2 sodium hydrogen sulfide to 100g of this polyamine derivative
72ml of a mixture of 5g and 25g of sodium pentasulfide
g, the same four metal ion-containing aqueous solution 1 as in Example 1
000 d, and the floc precipitation time, floc formation (2), and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 4 372 g of water was charged into the same apparatus as in Example 1, and then 70.7 g of hexamethylene diamine was finely pulverized and dispersed in water, and 141.4 g of carbon disulfide was heated at 40°C.
After dropping, W1 was formed at the same temperature.

Next, 248 g of 30% aqueous sodium hydroxide solution was added, the temperature was raised to 50°C, and the reaction was carried out for 1.5 hours. After the reaction is completed, insoluble components are filtered off, washed with water, further washed with acetone, crushed and dried under reduced pressure to obtain a sulfur content of 4 having a sodium salt of a dithiocarboxy group as an N-7;- substituent.
6.5wt% polyamine derivative pulverized product 203.7
I got g.

75 thorium tetrasulfide to 100 g of this polyamine derivative
．． 59 mg of the mixture were added to 1000 ml of the same four metal ion-containing aqueous solutions as in Example 1,
In the same manner as in Example 1, the floc precipitation time, floc production amount, and residual metal ion temperature in the filtrate were measured. The results are shown in Table 1.

Example 5 89 g of phenylene diamine, 282 g of water-acetone (1:1) and 398 g of a 20 wt% aqueous sodium hydroxide solution were charged into the same apparatus as in Example 1, and 9 fB of carbon disulfide was pressurized at 80°C. The reaction was carried out for 3 hours at this temperature. Then, it was purified in the same manner as in Example 1, and the sulfur content was 42.
．． 244.9 g of a 9% polyamine derivative was obtained.

5 sodium hydrogen sulfide to 100 g of this polyamine derivative
0g of the mixture was added to 1000ml of the same four metal ion-containing aqueous solutions as in Example 1, and the floc precipitation time, floc production amount, and concentration of flocs in the filtrate were determined in the same manner as in Example 1. The residual metal ion concentration was measured. The results are shown in Table 1.

Example 6 90.2 g of N-propyltriethylenetetramine and 640 g of a 15 wt% aqueous sodium hydroxide solution were charged into the same apparatus as in Example 1, and 172.8 g of carbon disulfide was reacted in the same manner as in Example 1. Sulfur content 40.8 with dithiocarboxy group as N-substituent after purification and drying
301.9 g of a wt% polyamine derivative was obtained.

100g of this polyamine derivative and 10g of sodium trisulfide
52 mg of the mixture in which 0 g was mixed with 4
Seed metal ion-containing aqueous solution too.

-, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 7 76 mg of a mixture of 100 g of the same polyamine derivative as in Example 5 and 50 g of sodium monosulfide was added to 1000 d of the same four metal ion-containing aqueous solutions as in Example 1, and the same procedure as in Example 1 was carried out. The floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured.

The results are shown in Table 1.

Example 8 52 mg of a mixture of 100 g of the same polyamine derivative as in Example 6 and 100 g of sodium monosulfide was added to 1000 ril of the same four metal ion-containing aqueous solutions as in Example 1, and the same procedure as in Example 1 was carried out. floc settling time,
The amount of flocs produced and the concentration of residual metal ions in the filtrate were measured. The results are shown in Table 1.

Comparative Example 1 116 mg of the same polyamine derivative as in Example 1 was added to 1000 g of the same four metal ion-containing aqueous solution as in Example 1.
ril, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 132 mg of sodium diethyldithiocarbamate was added to 1000 mg of the same aqueous solution containing four metal ions as in Example 1.
ml, and the floc precipitation time, floc production amount, and residual metal ion concentration in the filtrate were measured in the same manner as in Example 1. The results are shown in Table 1.

[Effect of the Invention C As explained below, the metal collection method of the present invention is characterized in that a polyamine salt-W body having at least one dithiocarboxy group or a salt thereof as an N-substituent in one molecule, Sodium sulfide, sodium polysulfide, hydrogen sulfide 1
- At least one type of metal tllY collector is added to wastewater containing metal ions as a metal tllY collection agent to collect and remove metal ions from wastewater. Metal ions in wastewater can be efficiently collected and removed even with a small amount of metal trapping agent added. Moreover, even if the polyamine HA used in the present invention >31 is used alone, it can sufficiently remove 1 ili of metal ions, but monosulfide, sodium polysulfide, sodium polysulfide, etc.
Because it is used in combination with at least one type of sodium hydrogen sulfide, the two act synergistically, resulting in an even faster sedimentation rate of flocs than when polyamine derivatives are used alone, resulting in extremely efficient It has the effect of collecting and removing ions.

Hand 3 Da ε (Jyukosho (Spontaneous) April 28, 1985 Michibe Uga, Commissioner of the Patent Office 2, Name of the invention Metal collection method 3, Relationship with the old case for amendment Patent applicant address Tokyo 66-1, Horikiri 4-chome, Katsushika-ku Name Miyoshi Oil & Fat Co., Ltd. Company Representative Mikiri 12 Line: 8 Agent 101 Address 2-75 Kanda Sakuma-cho, Chiyoda-ku, Tokyo Voluntary decision on basis of amendment order (Heavy Industries 6, amendment (Father-in-law (1) "20 Detailed Description of the Invention" on page 1, line 12 of the specification)
shall be amended to read "3. Detailed description of the invention."

(2) "Polyamine Fa'R monolithic and sodium monosulfide" on page 3, lines 19-20 is corrected to "polyamine derivative and sodium monosulfide."

(3) 7 on page 5, line 8...Can be replaced.

”, insert the following sentence.

7.Furthermore, a part of the active hydrogen of the dithiocarboxy group is substituted with an alkali combination, an alkaline earth metal, ammonium, etc. to obtain a polyamine derivative having a dithiocarboxy group and a salt of a dithiocarboxy group as a substituent. You can also do it.

(4) Delete "Aniline," on page 6, line 1.

f5) Correct “Tolidine base” in the inter-Q9 line to “Tolidine”.

(6) Correct "3 to 30 carbon atoms" in the 7th true line 6 to 7 to "2 to 30 carbon atoms."

that's all

Claims (1)

[Claims] Adding a polyamine derivative having at least one dithiocarboxy group or its salt as an N-substituent in one molecule and at least one of sodium monosulfide, sodium polysulfide, and sodium hydrogen sulfide to wastewater containing metal ions. A metal collection method characterized by collecting and removing metal ions from wastewater.