WO1980001249A1

WO1980001249A1 - Solidification of harmful solid waste

Info

Publication number: WO1980001249A1
Application number: PCT/JP1978/000062
Authority: WO
Inventors: H Kubota
Original assignee: Taken Aka Komuten Kk; H Kubota
Priority date: 1978-12-20
Filing date: 1978-12-20
Publication date: 1980-06-26

Abstract

Harmful solid waste containing harmful pollutants such as heavy metals, harmful organic pollutants and the like is added and mixed with lipids and cement-based solidifying agent consisting essentially of hydraulic cement to be solidified, thereby effectively preventing the elution of the harmful pollutants.

Description

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Specification

How to solidify hazardous waste

Technical field

The present invention provides a mud, powder or granular material that, if left unchecked, is contaminated with toxic substances that may directly or indirectly adversely affect ecosystems. Hazardous wastes such as various industrial wastes and sedimentary mud or soil (hereinafter referred to simply as "hazardous wastes" in the present invention) are referred to as landfill embankment, embankment, At the same time as solidifying the hazardous waste, the hazardous waste is solidified in order to recycle it as a useful material for molded materials, such as D used for reclamation and land development. The technology relates to a technique for trapping harmful pollutants contained in a substance in a solidified substance and detoxifying the substance, such as the generation of secondary pollution.

京 Kyoto Technology

In general, hazardous waste such as sludge that accumulates as sediment of nearby rivers, ports, lakes and marshes, and sludge discharged from the chemical industry or various industries that use chemicals In many cases, in addition to inorganic harmful pollutants such as heavy metals, many cases contain organic chlorine compounds, phosphorus compounds, sulfur compounds, nitrogen compounds, arsenic compounds, mercury compounds, copper compounds, and the like. If left unchecked, it will cause various harmful effects on the ecosystem and cause serious environmental problems as a source of environmental pollution.Therefore, urgent measures are needed in this area. . As a measure for detoxifying such hazardous wastes, a common method that has been practiced in the past is to use conventionally known hydraulic cement or water for hazardous wastes. (Including cementitious gypsum, which is hard), and solidify by adding and mixing cementitious stiffeners whose main component is! ), The ability to contain harmful pollutants in the solidified product; the solidification method using only the existing cement-based solidifying material alone does not remove heavy metals, etc. Even if it can be fixed, the effectiveness of organic harmful pollutants is questionable.]? In some cases, organic harmful pollutants from solidified substances In some cases, re-elution promoted secondary pollution, but had the opposite effect.

The cause of this tendency is that many of the organic harmful pollutants mentioned above; the chemical compatibility with the hydration products of the cement solidified material essentially < This is due to the lack of properties, but in some cases, due to the formation of an alkaline medium during the hydration process of the cement cement.]? It may also be due to increased solubility of organic harmful pollutants in water.

Disclosure of the invention

In particular, the object of the present invention is to effectively fix even organic harmful contaminants which have been difficult to fix by using the cement solidifying material alone as described above, and We do not propose a method that can be implemented very easily, both practically and economically.

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-0 no The point is that. -The present inventor considers various organic wastes containing various synthetic organic pesticides and organic toxic contaminants such as PCB and alkylmercury in addition to harmful contaminants such as heavy metals. In the course of promoting research on a method of solidifying using various existing cement-based solidifying materials and encapsulating and fixing harmful pollutants in the solidified material, the aforementioned cement was developed. A small amount of fatty oil or fatty acid, or a mixture of both, or a lipid containing both as a main component (hereinafter referred to simply as a lipid in the present specification) )) A new method of using together! ) Despite the heavy metals, it has been found that particularly harmful organic contaminants can be contained and fixed in an extremely effective solidified substance, and that they can be prevented from re-eluting. . Immediately, many organic harmful pollutants are difficult to fix due to poor affinity with the hydrated products of cement-based solidifying materials. Through lipids, which have a high affinity for contaminants, they can be extremely effectively contained in the matrix of hydrated products of cement-based hardwood. And were obtained through experiments.

In general, many of the organic toxic pollutants formed solvates with, dissolved, and adsorbed to lipids because they were themselves lipophilic. ! ), Which has the property of being added to the unsaturated bond of lipid and fixed to the lipid, but the lipid formed in such a state is Furthermore, it combines with calcium hydroxide, which is a hydration product of cement-based solidification material, to convert it into more stable and highly hydrophobic rubystone. Serves as a carrier for organic harmful pollutants and is contained in the matrix of the hydrated product of the cement-based solidifying material, so that the effects of the present invention described below can be obtained. It is considered to be something.

The lipid is selected in consideration of its acid value, iodine value, oxidation value, melting point (or freezing point), refractive index, carbon number, and compatibility with organic harmful substances. It is necessary, but practically, most fatty oils or fatty acids that are liquid at room temperature are useful.

However, from an economic point of view, rather than using specially refined and expensive ones to carry out the above process, crude or waste edible oils or various oil preparations must be used. It is preferable to use by-products or waste products containing fatty oils and fatty acids produced as a by-product in the oil and fat refining process, and particularly, fat and oil refining waste clay adsorbing a large amount of lipids is useful. In this case, in particular, there is an extremely large side effect that the waste can be effectively reused while also treating the by-products and wastes with low added value. Therefore, the significance of implementing this method is even greater.

In carrying out this method, the amount of lipid added depends on the type and content of hazardous pollutants in hazardous waste, the type and state of lipids used, and the amount of hazardous pollutants from solidified matter. Forgiveness

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—0 ； It should be determined by taking into account the dissolution amount, etc., but in general, the effect of fixing harmful pollutants improves in proportion to the amount of lipid added, and reaches a certain limit and peaks off.] However, it is not preferable to add an unnecessarily large amount, since the solidification strength of the solidified product is rather lowered. Normally, the amount of harmful pollutants in the target hazardous waste is extremely small, so that the amount of lipid added should be correspondingly small and sufficient. In the case of dredged sludge with contaminated sediment as a material, a small amount in the range of about 1 / 10,000 to 1/20 of the sludge weight is sufficient.

Then, in order to sufficiently disperse such a small amount of lipid by adding a large amount of hazardous waste, emulsification was carried out in advance using a surfactant or the like to be added.

Was dispersed in a suspension in water such as bentonite (or may be used in combination with a sexual agent), or the amount of lipid was previously mixed evenly with the cement solidified material. It is also possible to use lipids and cement-based solidifying materials in hazardous waste vegetables, even if they are used in a state of remittance. It doesn't matter what you do, even if you're ahead of it. When the lipid dispersion treatment is performed by blending with the cement-based hardening material, the interaction with the oil-based hardening material during a long period To avoid reaction, use fatty acids or fatty oils with particularly high acid value as the quality of use. That is not good.

Hazardous torment substances containing organic harmful pollutants solidified by this method have the property that the organic harmful pollutants contained in the substance themselves inhibit the growth of microorganisms. Therefore, despite the fact that the lipid is relatively biodegradable when added and mixed, the effect of fixing the organic harmful contaminants in the listening period is maintained for a long period of time. Paradoxically, it can be said that as long as the organic harmful contaminants are present in the solidified substance, its fixing effect is not lost, but In addition, lipids eventually react with calcium hydroxide, which is a hydration product of cement-based solidifying materials, to be able to resist biodegradability and to be chemically The conversion to highly stable hydrophobic calcium limestone also contributes to the long-lasting effect of fixing organic harmful pollutants.

Further, according to the present method, the added lipid reacts with heavy metals contained in the hazardous waste to form heavy metal stones which are insoluble in water and have a bactericidal or fungicidal effect. Formed and, in the presence of cement-based solidifying material, has the effect of confining and fixing the hydrated product in a matrix; also has the effect of fixing various heavy metals and organic harmful substances. It is extremely effective as a method for solidifying hazardous waste products that also contain substances.

As the hydraulic cement used as the cement-based solidifying material, the following can be used: Baltland cement (ordinary, early strength, and c-vpi). Various portland cements, such as super-high strength, are desirable in terms of effectiveness and economy, but blast furnace cement, silica cement, flyer It is acceptable to use slush cement, bozolan cement, or high-aluminum cement.

In addition, the present inventor has obtained further new findings as described below while continuing the experimental cutting of the above method. In other words, according to the method used in the present invention, the existing hydraulic cement is not used alone as the cement-based solidifying material, but these hydraulic cements are used. The use of cement-based solidified cement containing the following additives with the main composition X.II), solidification of hazardous waste and removal of hazardous pollutants in hazardous waste materials It has been found that the containment effect is dramatically increased.

The cement-based solidifying material is composed of [Α] hydraulic cement, [B] aluminum sulfate, bright ban, ferrous sulfate, and ferrous sulfate. At least one sulfate selected from the group consisting of:

[C] at least one type of alkali metal that is far from carbonates, bicarbonates, and silicates of alkaline metals; It is composed of four kinds of earth metal hydroxides and tobacco oxides.] Even if these are used alone and mixed with hazardous wastes, the hazardous wastes are not It has the function of solidifying and containing and fixing the harmful contaminants contained therein (see Japanese Patent Application No. 52-59884). In addition to the use of cement-based cement containing cement

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, Then: -The method of using lipid together with existing cement-based solidifying material, or the method of using only cement-based solidifying material with additive aid It is imagined from the effects of premature death More excellent effects are exhibited.

The full reasons why such a synergistic effect can be obtained are not yet clear, but one possible reason at present is as follows. In other words, the fats and oils react with the hydrated product (calcium hydroxide) of the cement-based solidifying agent to be degraded, thereby exhibiting the effect of continuously fixing organic harmful pollutants. As described above, in this case, the alkaline earth metal hydroxide required for the above-mentioned deterioration is generated from cement solidified material. Since it must be provided only from the hydrated product, its oxidation reaction proceeds slowly and in a limited amount of time and quantitatively, waiting for the production of the hydrated product. This will be. When the point oils and fats and the above-mentioned additives are used together, the cement solidifying material is used in combination with a sufficient amount of alkaline metal hydroxide (from the above-mentioned component [D ), The oils and fats can be rapidly and completely removed without waiting for the raw K of the hydrated K material of the cement solidified material. I suppose that the excellent effects as described above can be obtained.

The amount of each component to be used in the cement-based solidifying material containing the additive is usually determined according to the following general rule.

Principle 1: The amounts of components [B] and [C] used are almost identical to each other.

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Principle 2: The amount of the component [D] is low Na rather the well component (B), and anti to pair each, Ru der chemistry than the sum of the theoretical amount that obtained by this [C] _σ

Principle 3: The ratio of the total amount of the components [：], [: C] and [D] to the hydraulic cement [A] is almost 0 · 05 in terms of anhydride. Must be within the range of 1. In accordance with these principles, the optimal amount of each component in the solidified material), [B], [C], and [D] can be determined. Type, water content in hazardous waste materials, harmful pollutants and hydraulics contaminated in waste materials, hydration of hydraulic cement, content of interfering substances, already mixed from the beginning The content of the same kind of components as [B], [C], and [D], and the performance expected of the finally obtained solidified product, etc., may be appropriately modified. You can do it. For example, if the hazardous waste is sewage sludge dewatering cake, etc., a large amount of lime as a super-aid is mixed, so that the component [D] may be used in a considerable amount. Can be deducted. Also, when the hazardous waste is metal pickling sludge, flue gas desulfurization sludge, etc., lime used as a neutralizing agent was included too much j? However, since it contains gypsum and metal salts as neutralization products, the ratio of each component in the additive is appropriately determined in consideration of the amount and chemical properties of these substances. Ability to adjust;

As described above, the present invention provides a cement-based solidifying material (most preferred). This is a very simple method of adding a small amount of fat to the above-mentioned additive-incorporated [5 cement-based solidifying material], and is practically and economically. It is extremely easy to implement.] 3 However, organic harmful substances, which were difficult to fix by the conventional method described above, can be securely contained and fixed. It has a remarkable advantage of being able to maintain a long-lasting, excellent containment and fixing effect that does not cause secondary pollution due to elution. The industrial profits that contribute to the economy are enormous.

As the cement-based solidifying material used in the present invention, the above-described iP cement-based solidifying material containing an additive aid is most preferred. However, this is not a limitation, and as described in the first part of this chapter, as long as hydraulic cement is used as the main material, existing cement-based cement Is not always applicable.

In addition, a water reducing agent, a setting accelerator, and a setting retarder used as a normal cement admixture or as an admixture with respect to the cement solidification agent used in the present invention. Agents, foaming agents, foaming agents, water-proofing agents, coloring agents, fungicides, antibacterial agents, fibrous reinforcing materials, fillers, polymeric admixtures, pozzolanic admixtures, a On sealants, surfactants, intumescents, etc. can be used in combination depending on the purpose of each, as long as there is no particular problem.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, representative examples showing the results of the method of the present invention will be described.

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\\ ': 0 However, it should be mentioned that the present invention is not limited to these experimental examples. .

[Eyelids ^ 1]

Using dredged sludge from harbor sediment and river sediment containing various harmful pollutants (moisture content and harmful pollutant content of each dredged sludge are shown in Table 1, the latter In the case of river sediment dredging, the appropriate amount of parathion and methylmercury is added to artificially further contaminate the riverbed). The material was solidified with the existing cement-based solidified material, and the unconfined compressive strength of each solid and the amount of harmful pollutants eluted were examined. The solidification method is as follows: 100 parts of dredged sludge (hereinafter, “part” means all parts by weight) in the present specification. First, 0.3 parts of lipid was added and mixed, and then, 20 parts of cement solidified material was added and mixed. These mixtures were molded, cured, and solidified in accordance with Japanese Industrial Standards A 1 1 3 2 'How to make concrete strength test specimens', and reached a material age of 4 weeks. At that time, a compressive strength test was conducted in accordance with Japanese Industrial Standard A111, `` Concrete compressive strength test method '', and at the same time, the Japanese government Leaching test of harmful pollutants was carried out in accordance with the subsequent revision of the Environmental Agency Notification No.13, Showa 48, “Testing Methods for Hazardous Substances Contained in Industrial Wastes” (Akagami Landfill). Was. Table 1 summarizes the test results. Table I

River sediment Dredging 泥 Mud (water content 6 81o)

Elution concentration (ppm) of harmful contaminants from solidified matter or

Solidified material used Uniaxial pressure Raw dredging content of harmful pollutants in mud (* marked ppm)

Shrink strength

Cement-based archi 6 domi

Solidification agent Fat P C B Organic λ Total mercury Cyanide

'Le mercury chrome lead Arsenic

3.5 ND <0.2 0.001 0.009 ND 0.6 ND 0.07 0.05 0.05 No existing solidified material 3.8 ND <0.1 <0.001 0.005 ND 0.07 ND 0.08 ND Additive aid 3. 3.0 NDNDDND 0.005 ND Solidified 釗 ※※※ 0.00 0.001 0.001 NDN

-!

Cement soybean oil 3.3 N D N D N D <0.001 N D <0.05 N D N D N D Same as existing solidified material Same as above 3.

_Λ ※ _η raw dredged sludge ND 1 0.1 0.8 1 9 8 0.0 4 7.7 1 0.3 1 2 1 3.8

(ND indicates no detection)

* For textile processing

Raw waste, mainly composed of fatty acids

** Ordinary Portland cement 83 parts, ferrous sulfate heptahydrate 12 parts, sodium carbonate 5 parts tt compound and slaked lime 10 shao (Special No. 52-59848)

From the results of Example 11, it is found that when a small amount of cement is used in combination with various cement-based solidifying materials, the uniaxial compressive strength of the solidified product is slightly reduced, but the effect of harmful pollutants is significantly reduced. You can see that it improves. 9) In other words, the effect of using a cement-based solidifying material with additive and lipid in combination is remarkable.

(Excellent example 2)

Scientific name Da cachlorooc tahyd ro ~ l .3 · 4—mete o-2H-cyclob-utaCcdj pentalen-2-one 52.5% moisture content

PH7 -3, ignition loss 10.5% (600C for 30 minutes), the content of organic silicon compound 10.2 ppm (based on dry mud)] Each of the solidified materials according to the present invention was subjected to a solidification treatment according to the requirements shown in Experimental Example 1, and the amount of the nucleated chlorine compound eluted from the solidified material was examined. Table 1 summarizes the results.

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Same as the note in Table 1

From the results in Table 2-, it was found that most of the cement-based solidified material's power against sediment dredged sludge contaminated with organochlorine compounds as used in this experimental example; Even when used alone and solidified, the effect of immobilizing the organochlorine compound was almost expected. By the way, when undissolved raw dredged sludge is subjected to the above-mentioned dissolution test of organochlorine compounds, the leaching agriculture is 5.0 ppb! In many cases, only the cement-based solidified material was used, showing a higher value than this value. This is due to the fact that many cement-based solidifying agents form an alcohol medium during the hydration process, and as a result, the solubility of the organic chlorine compound is increased as described above. It is considered to be something. On the other hand, when the cement solidification material was solidified using a small amount of lipid, the elution concentration of organochlorine compounds decreased significantly, and the combined use of lipid was significantly fixed. It turned out to be effective.

[Experimental example 3]

Port sediment dredged sludge contaminated with PCB [PCB content: 239 ppm (relative to dry mud), water content: 78%, ignition loss: 35% [600 V, 30 minutes], PH 7.8] The effect of changing the use conditions of the fat of the solidified material according to the present invention on the PCB fixing effect was examined using the above method. For the cement-based solidifying material, select the J-solidifying agent containing the additive aid shown in Experimental Example 1 above, and use 25 parts of this for 100 parts of dredged sludge, and also use lipid together. Was carried out by changing the kind, condition, order of addition and amount of addition. The dissolution test of the PCB was performed on the solidified material cured in a room-temperature, humid air at 2 weeks and 4 weeks of material age according to the method of the Notification of the Environment Agency of Japan, mentioned in Experimental Example 1. Table 13 summarizes the results of these experiments.

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* As it is: As it is

Emanoresin: non-ionic yarn surfactant, net

Ethanol in water with lipid concentration of 20

Suspension: A small amount of a nonionic surfactant is added to a composition of net lipid 20 and bentonite 20% water 60, and the mixture is stirred and mixed. What I did

Blemix: Cement-based solidifying material with soybean oil at a specified concentration

It is mixed with and dispersed inside, and is used as a solidifying material for blemix.

«* Pre-addition First add and mix lipids into dredged sludge, then

Add and mix cement solidification material

Simultaneous addition Dredging of lipid and cement-based solidified material simultaneously.

Add to and mix with mud, or add and mix blemishes of lipid and cement-based solidifying material into dredged sludge.

Post-addition Add and mix in reverse order of pre-addition

Based on the results in Table-3, the type of lipid, its state, and the order of addition are as follows: It has little effect on the fixation effect of CB, but it was found that the effect decreased when the amount of lipid added was reduced below a certain limit. However, it can be said that practically even if the amount of lipid added is extremely small, it is effective.

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, "wipo _ ^ y Industrial applicability

In each of the experimental examples described above, its usefulness was proved.] However, the present invention is not limited to heavy metals in hazardous wastes, but can be fixed by the conventional cement-based solidifying material alone. Organic harmful contaminants, which had been difficult, can be contained and fixed to the extent that there is no need to worry about the occurrence of secondary pollution due to re-elution. Also, in the present invention, the lipids newly added to be used in combination are relatively easily available: ¾ Many are available, and therefore, both practical and economical are extremely easy. And its industrial benefits are enormous;

Claims

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① This is a method of solidifying hazardous waste containing hazardous pollutants. Ιϋ Hydraulic cement or hydraulic cement is mainly used for hazardous waste. It is characterized in that a cement solidifying material and a lipid are simultaneously or separately added and mixed, and that the harmful contaminants are sealed and fixed.

(2) The method according to the above (1), wherein the cement-based solidifying material is formed from the following components: [Α] hydraulic cement, [Β At least one or more sulfates returned from aluminum sulfate, light brown bread, ferrous sulfate, and ferrous sulfate; (C) carbonaceous metal, bicarbonate At least one or more kinds of metal salts selected from the group consisting of salts and silicates; [D] hydroxides or oxides of Al77 lithium earth metal. The method according to claim 1, wherein the fat or oil is a fatty oil or a fatty acid, or a mixture of the two, or a mixture of both. It is. The method according to claim 3, wherein the lipid described in fir is a by-product in crude product or waste edible oil, or in an appropriate amount of oil production or in an oil refining process. ^ Waste products containing fatty oils and fatty acids. According to the method described in claims or ^: ', the content of the cement yarn solidified material [A],

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(twenty one)

), [C], and (D) to be about 0.05 or 1 in terms of anhydride.

方法 The method of claim 1 wherein the method

Hazardous waste, etc. If the same kind of substances as those of components [Β], [C], and [D] in the cement-based solidified material already exist in φ, the amount is considered to be present. The amount of the component is reduced from the cement-based solidified material.

方法 The method of claim ia, wherein the method comprises:

The lipids are characterized in that about 1 / 10,000 or 1/20 of the weight of hazardous waste is added and mixed.

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