JP2007209829A - Disposal method of solid waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, though for solid wastes, e.g. fly and main ash, possibly containing harmful organic halides, e.g. dioxins, and/or heavy metals, there are proposed treating methods, e.g. a method of heat-treating incinerated ash under oxygen-deficient conditions in a highly closed atmosphere, these methods require special installations for retention of oxygen-deficient conditions and resultant high equipment investment and high maintenance costs of equipment, while current methods hardly permit simultaneous treatment of dioxins and heavy metals for wastes, e.g. fly ash, possibly containing dioxins and heavy metals. <P>SOLUTION: The disposal method of a solid waste comprises adding one or more reducing compounds selected from phosphorous and hypophosphorous acids and a metal-capturing agent having at least one of phosphate and carboxylate type functional groups with an ability of forming a complex with a metal to a solid waste to make harmless organic halides and heavy metals in the waste. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid waste treatment method capable of detoxifying harmful heavy metals and organic halides contained in solid waste such as fly ash.

  In recent years, when waste is incinerated at a garbage incinerator, etc., extremely toxic organic halides such as dioxins (PCDDS, PCDFS, etc.) are produced and contained in smoke in high concentrations. There is a big social problem. In addition, fly ash separated from smoke and main ash, which is the residue of incineration, may contain a large amount of organic halides such as dioxins. It has been pointed out that there is a possibility that a wide range of environmental pollution problems may occur from landfill disposal sites, such as organic halides leaching from rainwater, etc., and contaminating groundwater, rivers, and the like. Organic halides such as dioxins are extremely stable substances and do not disappear semi-permanently in the natural environment. Therefore, combined with their strong toxicity, they are regarded as important chemical substances for environmental pollution control. On the other hand, with the recent diversification of garbage, the fly ash may contain a large amount of harmful heavy metals, and there is a possibility of environmental pollution due to elution of heavy metals from waste landfills. Yes.

  As a method of reducing the amount of dioxins and the like contained in solid waste such as fly ash, a method of decomposing dioxins by heating fly ash in a non-passage system in an oxygen-deficient state (Patent Document 1), activated carbon Suppresses dioxin formation reactions of adsorbents that adsorb dioxin precursors such as silica, zeolite and zeolite, silicic acid compounds such as sodium silicate, phosphoric acid compounds, ammonium compounds such as diammonium hydrogen phosphate, and amine compounds A method of adding an inhibitor to the flue gas (Patent Document 2), a method of adding an amine compound such as monoethanolamine, triethanolamine, and methanolamine to fly ash (Patent Document 3), during incineration In the process where the temperature of the generated flue gas is 500 ° C. or lower, a method of bringing the flue gas into contact with a reducing agent (Patent Document 4), the flue gas temperature is 50 ℃ while in the above, after spraying an aqueous solution containing a reducing agent to the flue gas, a method of quenching the flue gas (Patent Document 5) it has been proposed.

Japanese Patent Publication No. 6-38863 JP-A-10-296050 Japanese Patent Laid-Open No. 10-272440 Japanese Patent Laid-Open No. 11-137952 JP 2002-102650 A

  However, in the method described in Patent Document 1, the dioxins cannot be effectively decomposed unless they are in an oxygen-deficient state, and in order to obtain an oxygen-deficient state, working in a closed system or in an inert gas atmosphere Since it is necessary to adopt a method such as elimination of intrusion, and a heat-treatment device with high airtightness is required, there is a problem that high costs are required for equipment investment, equipment maintenance, and the like. In this method, even if the chlorinated aromatic compound such as dioxins can be decomposed by heating once, the decomposition products may be combined under heating conditions to generate dioxins and the like again.

  The methods described in Patent Document 2 and Patent Document 3 can treat dioxins and the like without requiring special equipment as in the method described in Patent Document 1, but can treat heavy metals. Since this is not possible, the dioxins treatment and the heavy metal immobilization treatment must be performed separately, resulting in a problem that the treatment work becomes complicated. On the other hand, the methods described in Patent Documents 4 and 5 are used to reduce dioxins in the flue gas and reduce the heavy metals from the fly ash easily without using special processing equipment. Is possible. However, in the method of Patent Document 4 in which flue gas is treated at 500 ° C. or less, if the content of dioxins and their precursors and the content of heavy metals are large, the amount of reducing agent used must be increased, There was a possibility that it would be difficult to sufficiently treat heavy metals. Further, the method of Patent Document 5 may generate dioxins again if it is not rapidly cooled after the treatment. Further, in recent years, wastes such as fly ash are treated by the methods of Patent Documents 1 to 5 and other methods, and the amount of heavy metals eluted from the waste and the amount of remaining organic halides are regulated. Although required by law, there are many landfill sites where solid waste such as fly ash and main ash is landfilled before the law is enacted. Recently, heavy metals from these landfill sites It has been pointed out that there is a possibility of causing environmental pollution due to elution of organic halides.

  The present invention can be processed at a relatively low temperature without using a special heat treatment apparatus and the like, and even if low-temperature processing is performed, heavy metals and organic halides in solid waste can be safely and reliably removed. An object of the present invention is to provide a solid waste treatment method that can be detoxified.

That is, the present invention
(1) At least at least a phosphoric acid type functional group and a carboxylic acid type functional group capable of forming a complex between a compound selected from phosphorous acids having a reducing property and hypophosphorous acid and a metal and solid waste. A solid waste treatment method comprising detoxifying an organic halide and heavy metals in a solid waste by adding a metal scavenger having one kind,
(2) The solid state described in (1) above, wherein a compound selected from phosphorous acid and hypophosphorous acid and a metal scavenger are added to the solid waste, and detoxified at 50 to 650 ° C. Waste disposal methods,
Is a summary.

  According to the method of the present invention, harmful heavy metals contained in solid waste can be fixed, and harmful organic halides such as dioxins are also reliably decomposed to make solid waste harmless. be able to.

  In the present invention, phosphorous acids include phosphorous acid, potassium phosphite, sodium phosphite, sodium hydrogen phosphite, calcium phosphite, magnesium phosphite, ammonium hydrogen phosphite and the like. Of these, phosphorous acid, sodium phosphite, and calcium phosphite are preferable. The above phosphorous acid and phosphite may be used in combination of two or more. Examples of hypophosphorous acid include hypophosphorous acid, potassium hypophosphite, sodium hypophosphite, calcium hypophosphite and the like. Of these, hypophosphorous acid, sodium hypophosphite, and calcium hypophosphite are preferable. The above hypophosphorous acid and hypophosphite can be used in combination of two or more. In the present invention, either phosphorous acid or hypophosphorous acid may be used, or both may be mixed and used.

  As the metal scavenger, a compound having at least one of a phosphoric acid type functional group and a carboxylic acid type functional group is used. The metal scavenger may be one having one or two or more kinds of functional groups in one molecule or two or more having two or more different functional groups.

  Examples of the metal scavenger having a phosphoric acid type functional group include compounds obtained by reacting amines with aldehydes and phosphorous acid. Examples of the metal scavenger having a carboxylic acid type functional group include compounds having a carboxylic acid group obtained by reacting an amine with a monohalogenated carboxylic acid or an ester thereof. The above-mentioned compound having a phosphoric acid type functional group and a compound having a carboxylic acid type functional group may be either acid type (terminal hydrogen atom), salt type, or both. But it ’s okay. Examples of the salt-type carboxylic acid group include barium salts, sodium salts, potassium salts, calcium salts, magnesium salts, and amine salts, but sodium salts and potassium salts are usually preferable. A compound having a phosphoric acid type functional group and a compound having a carboxylic acid type functional group, both having an acid type functional group and a salt type functional group in one molecule, have only an acid type functional group. Those having only a salt-type functional group may be used, and one or a mixture of two or more thereof may be used. Examples of aldehydes to be reacted with amines include aliphatic saturated aldehydes such as formaldehyde, acetaldehyde and propionaldehyde, aliphatic dialdehydes such as glyoxal, aliphatic unsaturated aldehydes such as acrolein and propiolaldehyde, and aromatic aldehydes such as benzaldehyde. And heterocyclic aldehydes such as furfural and the like, and the above aliphatic saturated aldehydes and aromatic aldehydes are particularly preferable. Examples of phosphorous acids include the same phosphorous acids as described above, and phosphorous acid, sodium phosphite, and calcium phosphite are preferable. Monohalogenated carboxylic acids include chloroformic acid, chloroacetic acid, chloropropionic acid, chlorosuccinic acid, chloromaleic acid, chlorophthalic acid, chlorobenzoic acid, chloroacrylic acid, bromoacetic acid, bromopropionic acid, bromosuccinic acid, bromomaleic acid Bromophthalic acid, bromobenzoic acid, iodoacetic acid, iodopropionic acid, iodosuccinic acid, iodomaleic acid, iodophthalic acid, iodobenzoic acid and the like, and monochlorocarboxylic acid is preferred.

Examples of the amines used for obtaining a metal scavenger having a phosphoric acid type functional group or a carboxylic acid type functional group include monomethylamine, monoethylamine, monopropylamine, monoisopropylamine, monobutylamine, monoisobutylamine and the like. Monoalkylamines of: dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, ethylmethylamine, methylpropylamine, isopropylmethylamine, butylmethylamine, isobutylmethylamine, ethylpropylamine, ethylisopropylamine Dialkylamines such as butylethylamine, ethylisobutylamine, isopropylpropylamine, butylpropylamine, butylisobutylamine; Pyrenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetramine, tripropylenetetramine, tributylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, tetrabutylenepentamine, pentaethylenehexamine , Iminobispropylamine, monomethylaminopropylamine, aliphatic amines such as methyliminobispropylamine; monoalcohols such as monomethanolamine, monoethanolamine, monopropanolamine, monoisopropanolamine, monobutanolamine, monoisobutanolamine Amine; dimethanolamine, diethanolamine, dipropanolamine, diisopropanolamine Dialcoholamines such as dibutanolamine and diisobutanolamine; alkylphenylamines such as methylphenylamine, ethylphenylamine, phenylpropylamine, isopropylphenylamine, butylphenylamine and isobutylphenylamine; morpholine; 2-methylmorpholine, 2 -Ethylmorpholine, 2-propylmorpholine, 2-isopropylmorpholine, 2-butylmorpholine, 2-isobutylmorpholine, 3-methylmorpholine, 3-ethylmorpholine, 3-propylmorpholine, 3-isopropylmorpholine, 3-butylmorpholine, 3 -Monoalkylmorpholine such as isobutylmorpholine; dialkyl such as 2,3-dimethylmorpholine, 2,5-diethylmorpholine, 2-ethyl-5-methylmorpholine Morpholine; trialkylmorpholine such as 2,3,5-trimethylmorpholine, 2,3-dimethyl-6-ethylmorpholine; 2,3,5,6-tetraethylmorpholine, 2-ethyl-3,5,6-trimethylmorpholine Such as tetraalkylmorpholine; piperazine; 1-methylpiperazine, 1-ethylpiperazine, 1-propylpiperazine, 1-isopropylpiperazine, 1-butylpiperazine, 2-methylpiperazine, 2-ethylpiperazine, 2-propylpiperazine, 2- Monoalkylpiperazines such as isopropylpiperazine, 2-butylpiperazine, 2-isobutylpiperazine; dialkylpiperazines such as 2,3-dimethylpiperazine, 2,5-diethylpiperazine, 1,3-diethylpiperazine; 2,3,5-trimethyl Piperazine Trialkylpiperazines such as 1,2,5-trimethylpiperazine, 2,3-dimethyl-5-ethylpiperazine; 2,3,5,6-tetramethylpiperazine, 1,3,5,6-tetrapropylpiperazine, 3 -Tetraalkylpiperazines such as ethyl-2,5,6-trimethylpiperazine; pyrrolidine; 2-methylpyrrolidine, 2-ethylpyrrolidine, 2-propylpyrrolidine, 2-isopropylpyrrolidine, 2-butylpyrrolidine, 2-isobutylpyrrolidine, 3 -Monoalkylpyrrolidines such as methylpyrrolidine, 3-ethylpyrrolidine, 3-propylpyrrolidine, 3-isopropylpyrrolidine, 3-butylpyrrolidine, 3-isobutylpyrrolidine; 2,3-dimethylpyrrolidine, 2,4-diethylpyrrolidine, 2- Ethyl-3-methylpyro Dialkylpyrrolidines such as gin; trialkylpyrrolidines such as 2,3,4-trimethylpyrrolidine and 2,3-dimethyl-5-ethylpyrrolidine; 2,3,4,5-tetramethylpyrrolidine and 2-ethyl-3,4 , 5-trimethylpyrrolidine and other tetraalkylpyrrolidines; piperidine; 2-methylpiperidine, 2-ethylpiperidine, 2-propylpiperidine, 2-isopropylpiperidine, 2-butylpiperidine, 2-isobutylpiperidine, 3-methylpiperidine, 3- Ethyl piperidine, 3-propyl piperidine, 3-isopropyl piperidine, 3-butyl piperidine, 3-isobutyl tipiperidine, 4-methyl piperidine, 4-ethyl piperidine, 4-propyl piperidine, 4-isopropyl piperidine, 4-butyl piperidine, 4 Monoalkylpiperidines such as isobutylpiperidine; dialkylpiperidines such as 2,3-dimethylpiperidine, 2,5-diethylpiperidine, 2,4-dipropylpiperidine, 2-methyl-4-propylpiperidine; 2,4,6- Trialkylpiperidines such as trimethylpiperidine and 2,4-ethyl-6-propylpiperidine; tetraalkylpiperidines such as 2,3,5,6-tetramethylpiperidine and 2,3,4,6-triethylpiperidine; 2,3 , 4,5,6-pentamethylpiperidine, pentaalkylpiperidine such as 2,3,4,5,6-pentaethylpiperidine and the like.
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 Aromatic amines such as amine, 3,5-diaminochlorobenzene and aniline; cycloalkane polyamines such as 1,3-bis (aminomethyl) cyclohexane; polyethyleneimine, polypropyleneimine, poly-3-methylpropylimine, poly-2 -Cyclic imine polymers such as ethylpropylimine; polymers of unsaturated amines such as polyvinylamine and polyallylamine. It is also possible to copolymerize unsaturated amines such as vinylamine and allylamine with unsaturated amines such as dimethylacrylamide, styrene, methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene sulfonic acid, and their salts. Copolymers with other monomers having a saturated bond are also included. These can also use 2 or more types of mixtures.

  The amines may have a hydroxyalkyl group, an acyl group, an alkyl group or the like as an N-substituent. The N-hydroxyalkyl substituent can be introduced by reacting the amines with an epoxy alkane, and the N-acyl substituent is introduced by reacting the amines with a fatty acid. N-alkyl substituents are introduced by the action of the above amines and alkyl halides. The N-hydroxyalkyl substituent preferably has 2 to 28 carbon atoms in the alkyl group, and the N-acyl substituent preferably has 2 to 26 carbon atoms. The N-alkyl substituent preferably has 2 to 22 carbon atoms.

  Furthermore, polycondensation polyamines and polycondensation polyethylenimines in which the above amines and epihalohydrin are polycondensed can also be used. Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, epiiodohydrin, and the like. A metal scavenger having both a phosphoric acid type functional group and a carboxylic acid type functional group, after introducing one of a phosphoric acid type functional group and a carboxylic acid type functional group into the amines, It can be obtained by introducing a phosphate functional group by reaction, or by introducing a carboxylic acid functional group by reacting with a monohalogenated carboxylic acid or its ester. However, it is necessary that the active hydrogen bonded to the nitrogen atom derived from the amine remains after one of the phosphoric acid functional group and the carboxylic acid functional group is introduced.

  The ratio of phosphorous acid and / or hypophosphorous acid and metal scavenger is a weight ratio, and phosphorous acid and / or hypophosphorous acid: metal scavenger = 0.01: 99.99-99. 99: 0.01 is preferable, and 1:99 to 99: 1 is more preferable, but 25:75 to 75:25 is particularly preferable. The method of the present invention harms dioxins and heavy metals in solid waste by adding and treating phosphorous acid and / or hypophosphorous acid and a metal scavenger to the solid waste. The phosphorous acid and / or hypophosphorous acid and the metal scavenger may be added simultaneously or separately. When added separately, either phosphorous acid and / or hypophosphorous acid and a metal scavenger may be added first. As a method of processing by adding phosphorous acid and / or hypophosphorous acid and metal scavenger to solid waste, adding phosphorous acid, hypophosphorous acid, metal scavenger as it is and kneading And a method of spraying water after adding and kneading as it is, or a method of spraying an aqueous solution or suspension of phosphorous acid, hypophosphorous acid, metal scavenger on solid waste, etc. It is done. In this invention, 50-650 degreeC is preferable and, as for the temperature which processes solid waste, 200-400 degreeC is more preferable. When the solid waste is detoxified at a temperature of 50 to 350 ° C., mainly due to the effect of activating the reducing properties of phosphorous acid and / or hypophosphorous acid itself, and at 350 to 650 ° C. Due to the reduction effect of the decomposition product generated by the decomposition of phosphoric acids and / or hypophosphorous acid, an excellent effect that the decomposition of dioxins is promoted can be obtained. When solid waste is treated under heating, the heating method may be a single furnace such as a square kiln, a round kiln or a wheel kiln, a semi-continuous kiln such as a tunnel kiln or rotary kiln, or a direct kiln such as a burner. Examples of the method include heating by fire and using an electric furnace, but it is preferable to perform the treatment in a semi-continuous or continuous kiln such as a tunnel kiln or a rotary kiln. The treatment time varies depending on the treatment temperature, but is preferably 30 minutes to 1 hour.

  Examples of organic halides that can be treated by the method of the present invention include dioxin, PCB, ethylene chlorohydrin, allyl chloride, ethyl chloride, vinyl chloride, benzyl chloride, methyl chloride, methylene chloride, chlornaphthalene, chloropropylene, chlorbenzol. Chloroprene, acetylene tetrachloride, ethane tetrachloride, carbon tetrachloride, dichlorethane, dichlorbenzol, trichlorethylene, carbon fluoride chloride, brombenzol, bromoform, hexachloroethane, phosgene and the like. Examples of heavy metals include lead, cadmium, hexavalent chromium, arsenic, selenium, mercury, nickel, molybdenum, antimony, copper, zinc, and manganese. Examples of the solid waste to be treated in the present invention include fly ash, main ash, slag, sludge, and soil.

Hereinafter, the present invention will be described in more detail with reference to examples.
The metal scavenger used in the examples and comparative examples is shown below.
Metal collector 1: Disodium aminophosphate metal collector 2: Reactant of ethylenediamine, formalin and phosphorous acid (1: 4: 4 mol) Metal collector 3: Polyethyleneimine (average molecular weight 40000) per unit , Reaction product of 1 mol of monochloroacetic acid

Examples 1-4
Phosphorous acid, hypophosphorous acid and metal scavenger shown in Table 1 are added per 100 g of fly ash having a dioxin (DXNs) content of 5 ng-TEQ / g and a Pb content of 1500 mg / kg, and 350 by a rotary kiln. Heat treatment was performed at 0 ° C. for 1 hour. The amount of dioxins remaining in the fly ash after treatment and the amount of Pb elution from the fly ash after treatment were measured. These results are shown in Table 2 together with the results of reference examples in which the same treatment as in Examples 1 to 4 was performed without adding phosphorous acid, hypophosphorous acid, and metal scavenger.

(Table 1)

(Table 2)

Claims (2)

  At least one of a phosphoric acid type functional group and a carboxylic acid type functional group capable of forming a complex with a metal selected from a reducing phosphorous acid or hypophosphorous acid and a metal is added to the solid waste. A solid waste treatment method comprising detoxifying an organic halide and a heavy metal in a solid waste by adding a metal scavenger. The solid waste treatment method according to claim 1, wherein a compound selected from phosphorous acid and hypophosphorous acid and a metal scavenger are added to the solid waste and detoxified at 50 to 650 ° C. .