JP2007054769A - Metal immobilizing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal immobilizing agent capable of solving problems that water-soluble dithiocarbamate type metal immobilizing agent having excellent reactivity to metals and excellent efficiency of the treatment works has been extensively used for the metal immobilizing agent for immobilizing harmful heavy metals contained in wastes such as fly ashes discharged from garbage incinerator or the like is easily eluded by rains or the like, and a large amount of metal immobilizing agent must be added; the treatment burden of eluded water containing the metal immobilizing agent is large; and the treatment cost is high, less in elution losses, small in the amount of addition to wastes, and capable of efficiently immobilizing metals. <P>SOLUTION: This metal immobilizing agent contains polyamine salt of high molecular weight of amine-dithiocarbamate compound of low molecular weight in which dithioic acid groups bonded to nitrogen of amine of low molecular weight of 40-300 is formed into polyamine salt of high molecular weight of 1,000-300,000 in average molecular weight. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal immobilizing agent capable of insolubilizing a heavy metal contained in waste safely and reliably.

  There are various types of solid substances such as fly ash and incineration ash generated at garbage incinerators, dust, mines discharged from mines, activated sludge generated during wastewater treatment, and contaminated soil such as ruins of chemical factories. It contains metals and may contain a large amount of heavy metals that are harmful to the human body, such as mercury, cadmium, lead, zinc, copper, and chromium. When heavy metals are eluted from solid substances into groundwater, rivers, and seawater, serious environmental pollution is a problem.

  For this reason, it has been proposed to immobilize harmful heavy metals with a metal immobilizing agent before final disposal of solid waste by landfill, etc., and has an excellent ability to collect mercury and cadmium. Therefore, dithiocarbamic acid type metal fixing agents having a dithiocarbamic acid group or a salt thereof as a functional group are widely used. Dithiocarbamate-type metal immobilizing agents are highly water-soluble, have good reactivity to metals, and can be added to waste as an aqueous solution for efficient treatment. Fixing agents have been proposed (Patent Documents 1 to 4). On the other hand, a metal immobilizing agent for transition metal salts of powdered dithiocarbamic acid which is hardly soluble in water has also been proposed (Patent Document 5).

JP-A-8-269434 JP-A-10-76240 JP-A-10-77261 JP-A-10-140132 JP2003-301165A

  In order to immobilize harmful heavy metals in solid waste, dithiocarbamic acid-type metal immobilizing agents are added to the solid waste by various methods for metal immobilization. However, the water-soluble dithiocarbamic acid type metal fixing agent described in Patent Documents 1 to 4 and the like has a higher water solubility in the process where the fixing agent penetrates into the solid waste. Because it is easy to elute from the waste due to, etc., if the metal fixing agent is not added more than necessary, the metal cannot be fixed in the waste without fail, and if a large amount of metal fixing agent is added, the metal fixing agent As a result, there is a problem that the amount of the leaching amount increases and the burden on the facility for treating the leaching water containing the metal fixing agent increases. Moreover, if a large amount of the water-soluble dithiocarbamate-type metal immobilizing agent is used, the residual amount of alkaline substance in the soil may increase and adversely affect the growth of plants and microorganisms. In addition, it is pointed out that there is a possibility that the metal once fixed with the conventional metal fixing agent etc. may be re-eluted when it is exposed to rainwater etc. at the waste final treatment plant. In some cases, water-soluble dithiocarbamate-type metal immobilizing agents are easily eluted in a short period of time from solid waste. It was not possible to exert the effect of crystallization. Moreover, since the powdery dithiocarbamic acid transition metal salt type metal fixing agent described in Patent Document 5 contains a harmful transition metal (zinc, iron, cobalt, etc.), the metal fixing agent is not soluble in water. When reacting with the metal in the solid waste, the transition metal bound to the metal immobilizing agent is dissociated and released from the immobilizing agent, and the released transition metal is released by elution from the solid waste. There was a risk of contamination.

  The present invention provides a dithiocarbamic acid-type metal immobilizing agent that solves the above-mentioned problems of the prior art and can effectively immobilize metals in waste even with a small addition amount, and has excellent durability of the metal immobilization effect. For the purpose.

That is, the present invention
(1) Contains a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamic acid compound in which a dithioic acid group bonded to nitrogen of a low molecular weight amine having a molecular weight of 40 to 300 is a high molecular weight polyamine salt having an average molecular weight of 1000 to 300,000 A metal fixing agent, characterized by
(2) A low molecular weight amine in which a dithioic acid group bonded to nitrogen of a low molecular weight amine having a molecular weight of 40 to 300 is a low molecular weight amine salt having a molecular weight of 40 to 300 together with a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamate compound A low molecular weight amine salt of a dithiocarbamic acid compound, a high molecular weight polyamine dithiocarbamine in which a dithioic acid group bonded to nitrogen of a high molecular weight polyamine having an average molecular weight of 1000 to 300,000 is a high molecular weight polyamine salt having an average molecular weight of 1000 to 300,000 (1) the metal immobilizing agent comprising at least one high molecular weight polyamine salt of an acid compound;
(3) The metal immobilizing agent according to (1) or (2) above, which contains 0.1% by weight or more of a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamate compound,
Is a summary.

  Since the metal immobilizing agent of the present invention does not contain a transition metal, there is no risk of contamination due to elution of transition metal, and there is a possibility that it will be easily eluted by rainwater or the like, as in the case of conventional water-soluble dithiocarbamic acid type metal immobilizing agents. Therefore, it is not necessary to add a large amount of metal immobilizing agent in anticipation of elution loss, and the metal can be efficiently immobilized even with a small addition amount. Since the metal immobilizing agent of the present invention has little elution loss, the metal immobilizing agent cost during waste treatment can be reduced, and the treatment cost of the elution water containing the metal immobilizing agent is also reduced by conventional water-soluble metal immobilization. Compared to the agent, the effect can be drastically reduced. The metal immobilizing agent of the present invention remains in the solid waste for a long time and exhibits a metal immobilizing effect. Therefore, when the solid waste once subjected to the metal immobilizing treatment in the final treatment plant is reprocessed. Also has an excellent effect. In addition, when a low molecular weight amine salt of a low molecular weight amine dithiocarbamic acid compound is contained together with a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamic acid compound, the immediate effect on metal immobilization becomes higher, and the low molecular weight amine dithiocarbamic acid compound When the high molecular weight polyamine salt of the high molecular weight polyamine dithiocarbamate compound is contained together with the high molecular weight polyamine salt, there is an effect that the sustainability of the metal immobilization is further enhanced, and the low molecular weight polyamine salt of the low molecular weight amine dithiocarbamic acid compound is low. By selecting and containing a low molecular weight amine salt of a molecular weight amine dithiocarbamic acid compound or a high molecular weight polyamine salt of a high molecular weight polyamine dithiocarbamic acid compound, immediate effects and sustainability effects can be exhibited in a balanced manner.

Low molecular weight amine dithiocarbamine in which a dithioic acid group bonded to a nitrogen atom of a low molecular weight amine having a molecular weight of 40 to 300 constituting the metal fixing agent of the present invention is a salt of a high molecular weight polyamine having an average molecular weight of 1000 to 300,000 In the high molecular weight polyamine salt of an acid compound, examples of the low molecular weight amine include monoethylamine, monopropylamine, monoisopropylamine, monobutylamine, monoisobutylamine, amylamine, 2-ethylhexylamine, cyclohexylamine, and benzylamine. Alkylamine; dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, ethylmethylamine, methylpropylamine, isopropylmethylamine, butylmethylamine, Dialkylamines such as sobutylmethylamine, ethylpropylamine, ethylisopropylamine, butylethylamine, ethylisobutylamine, isopropylpropylamine, butylpropylamine, butylisobutylamine, diamylamine, di-2-ethylhexylamine; ethylenediamine, propylenediamine, Butylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetramine, tripropylenetetramine, tributylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, iminobis Propylamine, monomethylaminopropylamine, methyliminobispropyl Min, 1,3-propanediamine, 1,4-butanediamine, hexamethylenediamine, octamethylenediamine, N, N′-dimethylethylenediamine, N, N′-diethylpropylenediamine, N, N′-diethylethylenediamine, N , N′-diethylpropylenediamine and other aliphatic amines; monomethanolamine, monoethanolamine, monopropanolamine, monoisopropanolamine, monobutanolamine, monoisobutanolamine and other monoalcoholamines; dimethanolamine, diethanolamine, di Dialcohol amines such as propanolamine, diisopropanolamine, dibutanolamine, diisobutanolamine; methylphenylamine, ethylphenylamine, phenylpropylamine, isopropyl Alkylphenylamines such as phenylamine, butylphenylamine, isobutylphenylamine; morpholine; 2-methylmorpholine, 2-ethylmorpholine, 2-propylmorpholine, 2-isopropylmorpholine, 2-butylmorpholine, 2-isobutylmorpholine, 3- Monoalkylmorpholines such as methylmorpholine, 3-ethylmorpholine, 3-propylmorpholine, 3-isopropylmorpholine, 3-butylmorpholine, 3-isobutylmorpholine; 2,3-dimethylmorpholine, 2,5-diethylmorpholine, 2-ethyl Dialkylmorpholine such as -5-methylmorpholine; trialkylmorpholine such as 2,3,5-trimethylmorpholine and 2,3-dimethyl-6-ethylmorpholine; 2,3,5,6-tetraethylmorpholine , Tetraalkylmorpholines such as 2-ethyl-3,5,6-trimethylmorpholine; piperazine; 1-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-isopropylpiperazine, 1-butylpiperazine, 2-methyl Monoalkylpiperazines such as piperazine, 2-ethylpiperazine, 2-propylpiperazine, 2-isopropylpiperazine, 2-butylpiperazine, 2-isobutylpiperazine; 2,3-dimethylpiperazine, 2,5-diethylpiperazine, 1,3- Dialkylpiperazines such as diethylpiperazine; Trialkylpiperazines such as 2,3,5-trimethylpiperazine, 1,2,5-trimethylpiperazine, 2,3-dimethyl-5-ethylpiperazine; 2,3,5,6-tetra Methylpiperazine 1,3 , 5,6-tetrapropylpiperazine, tetraethylpiperazine such as 3-ethyl-2,5,6-trimethylpiperazine; pyrrolidine; 2-methylpyrrolidine, 2-ethylpyrrolidine, 2-propylpyrrolidine, 2-isopropylpyrrolidine, 2 -Monoalkylpyrrolidines such as butylpyrrolidine, 2-isobutylpyrrolidine, 3-methylpyrrolidine, 3-ethylpyrrolidine, 3-propylpyrrolidine, 3-isopropylpyrrolidine, 3-butylpyrrolidine, 3-isobutylpyrrolidine; 2,3-dimethylpyrrolidine Dialkylpyrrolidines such as 2,4-diethylpyrrolidine and 2-ethyl-3-methylpyrrolidine; trialkylpyrrolidines such as 2,3,4-trimethylpyrrolidine and 2,3-dimethyl-5-ethylpyrrolidine; 4,5- Tetraalkylpyrrolidines such as tramethylpyrrolidine and 2-ethyl-3,4,5-trimethylpyrrolidine; piperidine; 2-methylpiperidine, 2-ethylpiperidine, 2-propylpiperidine, 2-isopropylpiperidine, 2-butylpiperidine, 2 -Isobutyl piperidine, 3-methyl piperidine, 3-ethyl piperidine, 3-propyl piperidine, 3-isopropyl piperidine, 3-butyl piperidine, 3-isobutyl tipiperidine, 4-methyl piperidine, 4-ethyl piperidine, 4-propyl piperidine, Monoalkylpiperidine such as 4-isopropylpiperidine, 4-butylpiperidine, 4-isobutylpiperidine; 2,3-dimethylpiperidine, 2,5-diethylpiperidine, 2,4-dipropylpiperidine, 2-methyl Dialkylpiperidine such as 4-propylpiperidine; trialkylpiperidine such as 2,4,6-trimethylpiperidine, 2,4-ethyl-6-propylpiperidine; 2,3,5,6-tetramethylpiperidine, 2,3, Tetraalkylpiperidines such as 4,6-triethylpiperidine; pentaalkylpiperidines such as 2,3,4,5,6-pentamethylpiperidine, 2,3,4,5,6-pentaethylpiperidine, homopiperazine, etc. It is done.
Also thiomorpholine; 2-methylthiomorpholine, 2-ethylthiomorpholine, 2-propylthiomorpholine, 2-isopropylthiomorpholine, 2-butylthiomorpholine, 2-isobutylthiomorpholine, 3-methylthiomorpholine, 3-ethylthiomorpholine, Monoalkylthiomorpholine such as 3-propylthiomorpholine, 3-isopropylthiomorpholine, 3-butylthiomorpholine, 3-isobutylthiomorpholine, 2,3-dimethylthiomorpholine, 2,5-diethylthiomorpholine, 2,6-di Dialkylthiomorpholines such as propylthiomorpholine, 2-ethyl-3-methylthiomorpholine, 2-methyl-6-propylthiomorpholine; 2,3,5-trimethylthiomorpholine, 2,3,6-triethylthiomorpholine, etc. Trialkylthiomorpholine; tetraalkylthiomorpholine such as 2,3,5,6-tetramethylthiomorpholine, 2-ethyl-3,5,6-trimethylthiomorpholine; imidazolidine; 1-methylimidazolidine, 1-ethylimidazolidine, 1-propylimidazolidine, 1-isopropylimidazolidine, 1-butylimidazolidine, 1-isobutylimidazolidine, 2-methylimidazolidine, 2-ethylimidazolidine, 2-propylimidazolidine, 2-isopropylimidazolidine, 2- Butyl imidazolidine, 2-isobutyl imidazolidine, 3-methyl imidazolidine, 3-ethyl imidazolidine, 3-propyl imidazolidine, 3-isopropyl imidazolidine, 3-butyl imidazolidine, 3-isobutyl imidazole Lysine, 4-methylimidazolidine, 4-ethylimidazolidine, 4-propylimidazolidine, 4-isopropylimidazolidine, 4-butylimidazolidine, 4-isobutylimidazolidine, 5-methylimidazolidine, 5-ethylimidazolidine, Monoalkylimidazolidines such as 5-propylimidazolidine, 5-isopropylimidazolidine, 5-butylimidazolidine, 5-isobutylimidazolidine; 2,3-dimethylimidazolidine, 2,5-diethylimidazolidine, 4,5- Dialkylimidazolidines such as dipropylimidazolidine and 1-methyl-4-propylimidazolidine; trialkylimidazolidines such as 2,4,5-trimethylimidazolidine and 3,4-diethyl-5-propylimidazolidine; 3, 4, Tetraalkylimidazolidines such as 5-tetramethylimidazolidine, 1,2,4,5-tetramethylimidazolidine; pyrazolidines; 1-methylpyrazolidine, 1-ethylpyrazolidine, 1-propylpyrazolidine, 1 -Isopropylpyrazolidine, 1-butylpyrazolidine, 1-isobutylpyrazolidine, 2-methylpyrazolidine, 2-ethylpyrazolidine, 2-propylpyrazolidine, 2-isopropylpyrazolidine, 2- Butylpyrazolidine, 2-isobutylpyrazolidine, 3-methylpyrazolidine, 3-ethylpyrazolidine, 3-propylpyrazolidine, 3-isopropylpyrazolidine, 3-butylpyrazolidine, 3-isobutyl Pyrazolidine, 4-methylpyrazolidine, 4-ethylpyrazolidine, 4-propylpyrazolidine, 4 Isopropylpyrazolidine, 4-butylpyrazolidine, 4-isobutylpyrazolidine, 5-methylpyrazolidine, 5-ethylpyrazolidine, 5-propylpyrazolidine, 5-isopropylpyrazolidine, 5-butyl Monoalkylpyrazolidine such as pyrazolidine, 5-isobutylpyrazolidine; 3,4-dimethylpyrazolidine, 3,5-diethylpyrazolidine, 2,5-dipropylpyrazolidine, 3-methyl- Dialkylpyrazolidines such as 5-propylpyrazolidine; trialkylpyrazolidines such as 3,4,5-trimethylpyrazolidine and 2,4-diethyl-5-propylpyrazolidine; Tetraalkylpyrazolidine such as 5-tetramethylpyrazolidine and 1,4-diethyl-3,5-dipropylpyrazolidine; pyrrole; Lupyrrole, 2-ethylpyrrole, 2-propylpyrrole, 2-isopropylpyrrole, 2-butylpyrrole, 2-isobutylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-propylpyrrole, 3-isopropylpyrrole, 3-butyl Monoalkylpyrrole such as pyrrole and 3-isobutylpyrrole; 2,3-dimethylpyrrole, 2,5-diethylpyrrole, 2,4-dipropylpyrrole, 2-ethyl-4-methylpyrrole, 2-methyl-3-propyl Dialkyl pyrrole such as pyrrole; Trialkyl pyrrole such as 2,3,4-trimethylpyrrole, 2,3,5-triethylpyrrole; 2,3,4,5-tetramethylpyrrole, 2-ethyl-3,4,5 -Tetraalkylpyrrole such as trimethylpyrrole; imidazole; 2-methyl Ruimidazole, 2-ethylimidazole, 2-propylimidazole, 2-isopropylimidazole, 2-butylimidazole, 2-isobutylimidazole, 4-methylimidazole, 4-ethylimidazole, 4-propylimidazole, 4-isopropylimidazole, 4- Monoalkylimidazole such as butylimidazole, 4-isobutylimidazole, 5-methylimidazole, 5-ethylimidazole, 5-propylimidazole, 5-isopropylimidazole, 5-butylimidazole, 5-isobutylimidazole, 2,4-dimethylimidazole, Dialkyl such as 2,5-diethylimidazole, 2,4-dipropylimidazole, 2-ethyl-4-methylimidazole, 2-methyl-5-propylimidazole Midazole; trialkylimidazole such as 2,4,5-trimethylimidazole, 2,4,5-triethylimidazole; pyrazole; 3-methylpyrazole, 3-ethylpyrazole, 3-propylpyrazole, 3-isopropylpyrazole, 3-butyl Pyrazole, 3-isobutylpyrazole, 4-methylpyrazole, 4-ethylpyrazole, 4-propylpyrazole, 4-isopropylpyrazole, 4-butylpyrazole, 4-isobutylpyrazole, 5-methylpyrazole, 5-ethylpyrazole, 5-propyl Monoalkylpyrazoles such as pyrazole, 5-isopropylpyrazole, 5-butylpyrazole, 5-isobutylpyrazole, 3,4-dimethylpyrazole, 3,5-diethylpyrazole, 3,4-dipropylpyrazole Dialkylpyrazoles such as 3-ethyl-5-methylpyrazole; trialkylpyrazoles such as 3,4,5-trimethylpyrazole and 3,4,5-triethylpyrazole; phenylenediamine, o-, m-, p-xylylene diene Examples include amines, aromatic amines such as 3,5-diaminochlorobenzene and aniline; and cycloalkane polyamines such as 1,3-bis (aminomethyl) cyclohexane. Among these, diethylamine, piperazine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine are preferable. The dithioic acid group bonded to the nitrogen of the low molecular weight amine is introduced by replacing the hydrogen bonded to the nitrogen of the amine. When the low molecular weight amine has two or more hydrogen bonded to nitrogen, two or more dithioic acid groups may be introduced.

  On the other hand, high molecular weight polyamines that form dithioic acid group salts include cyclic imine polymers such as polyethyleneimine, polypropyleneimine, poly-3-methylpropylimine, poly-2-ethylpropylimine; polyvinylamine, polyallylamine, etc. Unsaturated polymers such as unsaturated amine polymers, unsaturated amines such as vinylamine and allylamine, dimethylacrylamide, styrene, methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene sulfonic acid, and their salts Among copolymers with other monomers having unsaturated bonds copolymerizable with amines, polyethyleneimine / benzyl chloride condensates, and the like, high molecular weight polyamines having an average molecular weight of 1000 to 300,000 can be mentioned. As the high molecular weight polyamine, polyethyleneimine, polyallylamine, and polyethyleneimine / benzyl chloride condensate are preferable. The high molecular weight polyamine salt of the low molecular weight amine dithiocarbamic acid compound is prepared by, for example, dropping carbon disulfide into an aqueous solution containing a low molecular weight amine and a high molecular weight polyamine in excess of the low molecular weight amine amount, followed by aging, followed by precipitation. The obtained solid can be obtained by a method such as filtration.

  The metal fixing agent of the present invention preferably contains 0.1% by weight or more of the high molecular weight polyamine salt of the low molecular weight amine dithiocarbamate compound, more preferably 10% by weight or more, and particularly 50% by weight. It is preferable to contain above. As the fixing agent contained in the metal fixing agent of the present invention together with the high molecular weight amine salt of the low molecular weight amine dithiocarbamate compound, a dithioic acid group bonded to nitrogen of a low molecular weight amine having a molecular weight of 40 to 300 has a molecular weight of 40 to 40. A low molecular weight amine salt of a low molecular weight amine dithiocarbamic acid compound, which is a salt of 300 low molecular weight amine, a dithioic acid group bonded to nitrogen of a high molecular weight polyamine having an average molecular weight of 1000 to 300,000 has an average molecular weight of 1000 to 300,000 It may contain at least one high molecular weight polyamine salt of a high molecular weight polyamine dithiocarbamic acid compound which is a salt of the above high molecular weight polyamine. Low molecular weight amine dithiocarbamic acid compound with low molecular weight amine dithiocarbamic acid compound, low molecular weight amine dithiocarbamic acid compound with low molecular weight amine salt is excellent in metal immobilization ability, high molecular weight polyamine dithiocarbamic acid compound with high molecular weight polyamine salt is heavy metal fixed Because of its long-lasting properties, it contains a low molecular weight amine salt of a low molecular weight amine dithiocarbamic acid compound and / or a high molecular weight polyamine salt of a high molecular weight polyamine dithiocarbamic acid compound, thereby improving or maintaining the immediate effect of metal immobilization. Can increase the sex. A low molecular weight amine salt of a low molecular weight amine dithiocarbamic acid compound or a high molecular weight polyamine salt of a high molecular weight polyamine dithiocarbamic acid compound can be reacted by dropping carbon disulfide into a low molecular weight amine aqueous solution having a molecular weight of 40 to 300, or an average molecular weight. It can be obtained by a method in which carbon disulfide is dropped into a 1000 to 300,000 high molecular weight polyamine aqueous solution and reacted. The metal fixing agent of the present invention has a solubility in water of 25 ° C. of 0.1% by weight or less.

  The metal fixing agent of the present invention has excellent fixing performance against lead, cadmium, hexavalent chromium, arsenic, selenium, mercury, nickel, molybdenum, antimony, copper, zinc, manganese, etc., and fly ash and incineration Suitable for immobilization of metals contained in solid waste such as ash, dust, mines, activated sludge, contaminated soil, waste once processed in the final treatment plant of waste, It can also be used for immobilization of metals in liquid waste such as exhaust gas and gaseous waste.

  As a method for treating solid waste with the metal fixing agent of the present invention, a spraying method described in JP-A-10-057937, for example, an aqueous solution or suspension containing a metal fixing agent is used. Examples include a method of adding to waste by spraying from above. Moreover, it can also be spread | dispersed in powder form and you may knead | mix, after spraying as needed. When the metal fixing agent of the present invention is added from above the waste, the metal in the waste is sequentially fixed while gradually penetrating into the waste, but compared to the conventional water-soluble dithiocarbamic acid type metal fixing agent. Since the water solubility is low, even if there is rainfall in the process of permeating into the waste, there is little possibility that the metal fixing agent will be eluted by rain water, and the metal can be fixed reliably.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the metal fixing agent used in the following examples is as follows.

(1) Metal immobilizing agent A: Polyethyleneimine salt of diethylenetriaminedithiocarbamic acid.
(2) Metal immobilizing agent B: Polyethyleneimine / benzyl chloride condensate salt of diethylenetriaminedithiocarbamic acid.
(3) Metal immobilizing agent C: Polyethyleneimine salt of triethylenetetramine dithiocarbamic acid.
(4) Metal immobilizing agent D: Polyethyleneimine / benzyl chloride condensate salt of triethylenetetramine dithiocarbamic acid.
(5) Metal immobilizing agent E: Polyethyleneimine salt of tetraethylenepentamine dithiocarbamic acid.
(6) Metal fixing agent F: A mixture containing 90% by weight of metal fixing agent E and 10% by weight of tetraethylenepentamine salt of tetraethylenepentamine dithiocarbamic acid.
(7) Metal fixing agent G: Mixture containing 80% by weight of metal fixing agent E, 10% by weight of tetraethylenepentamine salt of tetraethylenepentamine dithiocarbamic acid and 10% by weight of polyethyleneimine salt of polyethyleneimine dithiocarbamic acid .
(8) Metal immobilizing agent H: A mixture containing 90% by weight of metal immobilizing agent E and 10% by weight of polyethyleneimine salt of polyethyleneiminedithiocarbamic acid.
(9) Metal immobilizing agent I: Polyethyleneimine / benzyl chloride condensate salt of tetraethylenepentamine dithiocarbamic acid.
(10) Metal fixing agent J: Mixture containing 90% by weight of metal fixing agent I and 10% by weight of tetraethylenepentamine salt of tetraethylenepentamine dithiocarbamic acid.
(11) Metal fixing agent K: 80% by weight of metal fixing agent I, 10% by weight of tetraethylenepentamine salt of tetraethylenepentamine dithiocarbamic acid, polyethyleneimine / chloride of polyethylenimine / benzyl chloride condensate dithiocarbamic acid A mixture containing 10% by weight of a benzyl condensate salt.
(12) Metal immobilizing agent L: a mixture containing 90% by weight of metal immobilizing agent I and 10% by weight of polyethyleneimine / benzyl chloride condensate salt of polyethylenimine / benzyl chloride condensate.
(13) Metal immobilizing agent M: potassium diethyldithiocarbamate.

Examples 1-12, Comparative Examples 1-3
In order to improve water permeability, 100 g of silica sand was uniformly mixed with 100 g of fly ash produced by incineration of dust containing 1107 ppm of lead, and then packed in a chromatographic column with a glass filter. Next, after filling the fly ash with 3 g of the metal fixing agent powder and silica sand shown in Table 1 in order, 50 mL / day of water was added from the top of the column. After 3 months, 6 months, 12 months, 18 months, 24 months, and 30 months, the lead concentration in the aqueous solution eluted from the foot tube was measured. From these measured values, the rapid efficacy and sustainability of the metal fixing agent were evaluated according to the following criteria. Moreover, the presence or absence of the metal fixing agent residue in the fly ash after 30 months of water flow was confirmed by ultraviolet spectroscopy. These results are shown in Table 1.

Evaluation criteria for immediate effect When the lead elution concentration is suppressed to 0.05 ppm or less after 0.5 months ○
When the lead elution amount after 0.5 months exceeds 0.05 ppm △

Sustainability evaluation criteria Lead elution concentration is
When it is suppressed to 0.1 ppm or less until 30 months ○
When it is suppressed to 0.1 ppm or less until 18 months △
When exceeding 0.1 ppm by 18 months ×

Method for confirming the presence or absence of metal immobilizing agent Add 2 liters of water to the contents in the chromatographic column with glass filter, heat and stir for 30 minutes, filter, and heat the filtrate under reduced pressure to distill off the water. The operation was repeated 5 times, the residue was dissolved in a small amount of water, and the presence or absence of the drug residue was confirmed by ultraviolet spectroscopy. “Yes” indicates that the peak of the metal fixing agent was observed, and “No” indicates that the peak was not observed.

Claims (3)

  A dithioic acid group bonded to nitrogen of a low molecular weight amine having a molecular weight of 40 to 300 contains a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamate compound having a high molecular weight polyamine salt having an average molecular weight of 1000 to 300,000; Characteristic metal immobilizing agent.   A low molecular weight amine dithiocarbamic acid compound in which a dithioic acid group bonded to nitrogen of a low molecular weight amine having a molecular weight of 40 to 300 is a low molecular weight amine salt having a molecular weight of 40 to 300 together with a high molecular weight polyamine salt of the low molecular weight amine dithiocarbamic acid compound A low molecular weight amine salt, a high molecular weight polyamine dithiocarbamic acid compound in which a dithioic acid group bonded to nitrogen of a high molecular weight polyamine having an average molecular weight of 1,000 to 300,000 is a high molecular weight polyamine salt having an average molecular weight of 1,000 to 300,000. The metal fixing agent according to claim 1, comprising at least one high molecular weight polyamine salt. The metal immobilizing agent according to claim 1 or 2, comprising 0.1% by weight or more of a high molecular weight polyamine salt of a low molecular weight amine dithiocarbamic acid compound.