JP2004314005A - Cleaning method of sludge polluted with organic halogen compound, and its apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably treat an organic halogen compound without requiring much energy, and suitably treat sludge such as bottom sludge of the ocean and estuary containing much salts such as NaCl at no treatment cost in a cleaning method of sludge polluted with organic halogen sludge compound, and its apparatus. <P>SOLUTION: In the cleaning method of sludge polluted with the organic halogen compound, the sludge is subjected to the solid/liquid separation. The separated solid content is heated in the reducing atmosphere to decompose the organic halogen compound. The organic halogen compound contained in exhaust gas by the heating in the reduced atmosphere is supplied to an oil scrubber. The oil content in the oil scrubber is subjected to alkaline washing, and the organic halogen compound in the oil content after the alkaline washing is decomposed by alkaline metal. The organic halogen compound in the liquid separated by the solid/liquid separation is separated and removed by a water treatment means other than a reverse osmosis membrane. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for purifying sludge contaminated with an organic halogen compound, and more specifically, to purify sludge such as soil, debris and the like contaminated with organic halogen compounds such as polychlorinated biphenyl, dioxin and agricultural chemicals. The present invention relates to a purification method and an apparatus for achieving the above.
[0002]
[Prior art and problems to be solved by the invention]
As is well known, polychlorinated biphenyl, a kind of organic halogen compound, is very stable and difficult to be decomposed, and has high insulation (electrical resistance), so in the past, insulation materials such as transformers and capacitors, and heat media Or it was used for carbonless copy paper, but now it is prohibited to use for environmental reasons.
[0003]
However, there are still cases where traces are still present in solids such as soil and bottom mud, such as those that have been used in the past, and how these are decomposed and treated is important. It has become a challenge.
[0004]
As a technique for treating sludge contaminated with an organic halogen compound in this way, for example, a method of solid-liquid separation as shown in FIG. 6 is conceivable. However, the separated liquid may contain an organic halogen compound. Yes, the separated liquid cannot be discharged as it is.
[0005]
In addition, as shown in FIG. 7, it is conceivable to evaporate the separated liquid after solid-liquid separation, but in that case, a large amount of water must be evaporated, the heating amount increases, and a great deal of energy is required. It will be.
[0006]
Therefore, in order to solve these problems, the present patent applicant filed a patent application on a method and apparatus for purifying contaminated sludge contaminated with organic halogen compounds and heavy metals as of June 7, 2002. (Japanese Patent Application No. 2002-166633).
[0007]
In the invention according to this patent application, contaminated sludge contaminated with organic halogen compounds and heavy metals is subjected to solid-liquid separation, and the organic halogen compounds in the separated solids are dehalogenated in a reducing heating atmosphere and separated. The solution is separated by an ultrafiltration membrane, a reverse osmosis membrane or the like, and the organic halogen compound in the separated concentrated water is dehalogenated.
[0008]
However, in the present invention, since a reverse osmosis membrane is used, for example, when processing sludge such as ocean and estuarine bottom mud containing a large amount of salt such as NaCl, processing cost is required due to the problem of osmotic pressure, or There was a problem of insufficient processing.
[0009]
The present invention has been made in order to solve such problems, and can suitably treat an organic halogen compound without requiring a large amount of energy, and further includes oceans and estuaries containing a large amount of salts such as NaCl. Even when sludge such as the bottom mud is treated, the problem is that it can be suitably treated without incurring treatment costs. Specifically, when treating sludge containing 1% or more of salts, it is an object to be able to treat it more suitably without incurring treatment costs.
[0010]
[Means for Solving the Problems]
In order to solve such problems, the present invention was made as a method and apparatus for purifying sludge contaminated with an organic halogen compound. The feature of the method for purifying sludge was contaminated with an organic halogen compound. The sludge is separated into solid and liquid, and the separated solid is heated in a reducing atmosphere to decompose the organic halogen compound, and the organic halogen compound contained in the exhaust gas is supplied to the oil scrubber by heating in the reducing atmosphere. The oil in the oil scrubber is alkali washed, the organic halogen compound in the oil after the alkali washing is decomposed with an alkali metal, and the liquid separated by the solid-liquid separation is removed by water treatment means other than a reverse osmosis membrane. It is to separate and remove the organic halogen compound in the liquid.
[0011]
The sludge purification device is characterized by solid-liquid separation device 1 for solid-liquid separation of sludge contaminated with an organic halogen compound, and water treatment other than reverse osmosis membranes for the liquid separated by the solid-liquid separation device 1 Means for separating and removing the organic halogen compound in the liquid by means, and a reduction heat treatment apparatus for decomposing the organic halogen compound in the solid content by heating the solid content separated in the solid-liquid separator 1 in a reducing atmosphere 3, an oil scrubber 4 for supplying the organic halogen compound contained in the exhaust gas by heating in the reduction heat treatment apparatus 3 to collect the organic halogen compound in the oil, and the oil content of the oil scrubber 4 is washed with an alkali And a dehalogenation treatment device 6 for decomposing the organic halogen compound in the oil after the alkali cleaning with an alkali metal.
[0012]
As the water treatment means other than the reverse osmosis membrane, for example, one means or a combination of two or more means from sand filtration, oxidation treatment means such as ozone and hydrogen peroxide, solvent extraction method, coagulation sedimentation method and the like are used. .
[0013]
It is also possible to capture water vapor and dust contained in the exhaust gas by cooling before supplying the organic halogen compound contained in the exhaust gas to the oil scrubber without being decomposed by heating in a reducing atmosphere. is there.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(Embodiment 1)
First, an apparatus for purifying sludge contaminated with an organic halogen compound as one embodiment will be described.
[0016]
As shown in FIG. 1, the contaminated sludge purification apparatus of the present embodiment includes a solid-liquid separation apparatus 1, a sand filtration apparatus 2, a reduction heat treatment apparatus 3, an oil scrubber 4, an alkali cleaning apparatus 5, and a desorption apparatus. And a halogenation treatment apparatus 6.
[0017]
The solid-liquid separation apparatus 1 separates contaminated bottom mud containing heavy metals such as mercury, cadmium, lead, and arsenic in addition to polychlorinated biphenyl as an example of an organic halogen compound into a solid content and a liquid. For example, a filter press or a centrifuge is used as the solid-liquid separator 1.
[0018]
The sand filtration device 2 is a device for further separating the liquid component separated by the solid-liquid separation device 1 into a solid sludge component (SS component) and permeated water. As sand for sand filtration, sand detoxified by reduction heat treatment described later is used.
[0019]
An activated carbon device 7 having activated carbon is provided at the subsequent stage of the sand filtering device 2. In this case, instead of the activated carbon device 7, an oxidative decomposition device such as ozone oxidation or hydrogen peroxide, or an ultrafiltration membrane device can be provided.
[0020]
The reduction heat treatment apparatus 3 performs a dechlorination treatment by reduction heating, and includes a cylindrical container 8 as shown in FIG. The cylindrical container 8 has a passage for supplying air and nitrogen gas, and a rotary shaft 9 is rotatably attached in a substantially central longitudinal direction. A plurality of paddle blades 10 are attached to the rotating shaft 9.
[0021]
A storage portion 12 that stores a heat medium made of combustion gas fed by the blower 11 is formed on the outer peripheral portion of the cylindrical container 8. A heat exchanger 13 is provided outside the cylindrical container 8.
[0022]
The oil scrubber 4 is for supplying exhaust gas from the reduction heat treatment device 3 and mixing it with cleaning oil.
[0023]
Between the oil scrubber 4 and the reduction heat treatment device 3, an exhaust gas cooling device 14 for cooling and capturing water vapor and dust contained in the exhaust gas from the reduction heat treatment device 3 is provided.
[0024]
The alkali cleaning device 5 is for neutralizing the organic acid in the cleaning oil from the oil scrubber 4, and a sodium hydroxide aqueous solution after oil-water separation described later is returned and used for the neutralization.
[0025]
The dehalogenation treatment device 6 decomposes polychlorinated biphenyl in the cleaning oil supplied from the alkali cleaning device 5 by adding a sodium dispersant in which metallic sodium is dispersed in the form of fine particles in an organic solvent such as insulating oil. Therefore, water, isopropyl alcohol or the like, which is a reaction promoting substance, is further added to the dehalogenation treatment apparatus 6.
[0026]
A hydration tank 15 is provided on the rear stage side of the dehalogenation treatment apparatus 6. The hydration tank 15 is for hydrating the sodium dispersant that has not been consumed in the dehalogenation treatment device 6, and the permeated water from the activated carbon device 7 is used as a liquid for hydration. It is done.
[0027]
Furthermore, an oil / water separator 16 is provided on the rear side of the hydration tank 15. This oil / water separator 16 is for separating the decomposition liquid from the hydration tank 15 into oil / water, and the oil after separation is recovered as treated oil, and the water after separation is recovered as alkaline drainage. A part of the water is returned to the alkali cleaning device 5 in order to reuse sodium hydroxide contained in the water.
[0028]
Next, an embodiment of a method for purifying bottom mud containing 1% or more of salts such as oceans and estuaries contaminated with polychlorinated biphenyl as an example of an organic halogen compound using the above-described purification apparatus will be described. . The contaminated bottom mud contains heavy metals in addition to polychlorinated biphenyl, although not described in detail below.
[0029]
First, the contaminated soil containing polychlorinated biphenyl is supplied to the solid-liquid separator 1, and the solid-liquid separator 1 separates the soil into a solid and a liquid.
[0030]
The liquid component (separated liquid) separated by the solid-liquid separation device 1 is supplied to the sand filtration membrane device 2, and the filtered water filtered by the sand filtration device 2 is further supplied to the activated carbon device 7. A part of the filtered water is supplied to the exhaust gas cooling device 14 and used as cooling water. On the other hand, the solid content (SS content) separated by the sand filtration device 2 is returned to the solid-liquid separation device 1.
[0031]
In the filtered water supplied to the activated carbon device 7, polychlorinated biphenyl may remain, but the remaining polychlorinated biphenyl was adsorbed and removed by the activated carbon device 7, and the polychlorinated biphenyl was adsorbed and removed. The treated water will be discharged out of the system. A part of this treated water is supplied to a hydration tank 15 described later.
[0032]
Next, the solid content separated by the solid-liquid separation device 1 is supplied to the reduction heat treatment device 3. In this reduction heat treatment apparatus 3, polychlorinated biphenyl is decomposed.
[0033]
More specifically, the solid content separated by the solid-liquid separation device 1 is supplied to the cylindrical container 8 of the reduction heat treatment apparatus 3, and the cylindrical container 8 is supplied with nitrogen gas for reduction. It heat-processes at 200-600 degreeC by atmosphere. In some cases, air is supplied. In this case, heat treatment is sequentially performed in an oxidizing atmosphere and a reducing atmosphere. Moreover, it is preferable that heating temperature is 300-550 degreeC from a cost and the point of reactivity.
[0034]
In the cylindrical container 8, the rotating shaft 9 rotates as shown in FIG. 2, whereby the solid content is stirred by the plurality of paddle blades 10 attached to the rotating shaft 9. As a result, the polychlorinated biphenyl in the solid content is decomposed.
[0035]
The solid matter processed by the reduction heat treatment device 3 is discharged out of the system, and a part of the solid matter is used as a filter medium of the sand filtration device 2.
[0036]
The exhaust gas from the reduction heat treatment device 3 is supplied to the exhaust gas cooling device 14, and the water vapor and dust contained in the exhaust gas are cooled and captured in the exhaust gas cooling device 14. The removed water vapor and dust are returned to the solid-liquid separator 1.
[0037]
On the other hand, the exhaust gas from which water vapor and dust are captured and removed by the exhaust gas cooling device 14 is supplied to the oil scrubber 4. The oil scrubber 4 is supplied with cleaning oil (trans oil), and when polychlorinated biphenyl remains in the exhaust gas, the polychlorinated biphenyl is extracted into the cleaning oil.
[0038]
The washing oil containing polychlorinated biphenyl extracted by the oil scrubber 4 is supplied to the alkali washing device 5 and neutralizes the organic acid contained in the washing oil in addition to the polychlorinated biphenyl. That is, the exhaust gas may contain an organic acid generated by thermally decomposing an organic halogen compound or the like in the reduction heat treatment device 3, and this organic acid is supplied to the subsequent dehalogenation treatment device 6. Before being subjected to neutralization, the dehalogenation treatment device 6 prevents metal sodium from being consumed in addition to the reaction with the organic halogen compound.
That is, the consumption amount of metallic sodium in the dehalogenation treatment apparatus 6 is reduced. In addition, since alkaline drainage, which will be described later, is used for alkali cleaning, it is not necessary to add an aqueous alkali solution or the like from outside the system.
[0039]
The cleaning oil containing the organic acid neutralized by the alkali cleaning device 5 and polychlorinated biphenyl is supplied to the dehalogenation processing device 6, and the polychlorinated biphenyl is decomposed by the dehalogenation processing device 6. Become.
[0040]
That is, a sodium dispersant in which metallic sodium is dispersed in the form of fine particles in an insulating oil is added to the dehalogenation treatment device 6, and the metallic sodium in the sodium dispersant reacts with the polychlorinated biphenyl in the cleaning oil, Biphenyl chloride is dechlorinated and decomposed.
[0041]
Then, the reaction product biphenyl, sodium chloride, washing oil, and excess metal sodium not consumed in the dehalogenation treatment apparatus 6 are supplied to the hydration tank 15. The permeated water filtered by the activated carbon device 7 is supplied to the hydration tank 15, and the unconsumed metallic sodium is hydrated by the permeated water.
[0042]
The cleaning oil separated in the hydration tank 15 is recovered as treated oil, but a part of the cleaning oil is returned to the oil scrubber 4 as recycled oil and reused. In addition, the water separated into oil and water is recovered as alkaline drainage, but a part of the water is returned to the alkali cleaning device 5 and sodium hydroxide contained in the water is used for neutralization of the organic acid. Reused.
[0043]
As described above, in the present embodiment, since the liquid component separated by the solid-liquid separation device 1 is supplied to the sand filtration device 2 and the activated carbon device 7, the treated water from the activated carbon device 7 is treated with polychlorinated biphenyl. Is never contained. Further, the contaminated activated carbon used in the activated carbon device 7 is regenerated and reused in a reduction furnace. In this case, the treatment by the reduction furnace is preferably performed by returning the contaminated activated carbon to the reduction heat treatment apparatus 3 and regenerating it. As a result, the reduction heat treatment device 3 provided in the contaminated sludge purification device of the present embodiment can be used as it is, and as a result, the regeneration cost can be reduced, or excess is not discharged outside the system. There is an advantage.
[0044]
On the other hand, the solid content separated by the solid-liquid separator 1 is supplied to the reduction heat treatment device 3, and the polychlorinated biphenyl in the solid content is decomposed. The polychlorinated biphenyl that is not decomposed is supplied to the dehalogenation treatment device 6 through the exhaust gas cooling device 14, the oil scrubber 4, and the alkali cleaning device 5 while being contained in the exhaust gas discharged from the reduction heat treatment device 3. , Decomposed.
[0045]
Therefore, in this embodiment, the polychlorinated biphenyl in the contaminated bottom mud to be treated is not discharged out of the system at all and is completely decomposed.
[0046]
Moreover, in this embodiment, the liquid separated by the solid-liquid separation device 1 is not treated by the reverse osmosis membrane, but by the sand filtration device 2 or the like, so that the ocean or estuary containing a large amount of NaCl or the like is used. When processing bottom mud etc., processing cost does not cost or processing does not become inadequate.
[0047]
(Embodiment 2)
In the present embodiment, as shown in FIG. 3, an oxidative decomposition apparatus 17 is used instead of the sand filtration apparatus 2 of the first embodiment. In the oxidative decomposition apparatus 17, ozone is blown into the liquid separated by the solid-liquid separation apparatus 1. As a result, the organic halogen compound in the liquid is oxidatively decomposed.
[0048]
Since the organic halogen compound is decomposed by such oxidative decomposition, an oxidizing agent such as hydrogen peroxide can be used instead of ozone. Moreover, you may irradiate an ultraviolet-ray together with blowing of ozone and hydrogen peroxide.
[0049]
The treated water after oxidative decomposition is treated with an activated carbon device, but an ultrafiltration membrane treatment may be performed instead of the activated carbon device. In this case, the concentrated liquid is returned to the inlet side of the solid-liquid separator.
[0050]
Filtration of the liquid after solid-liquid separation in the activated carbon device 7, decomposition of polychlorinated biphenyl by heat treatment in the reduction heat treatment device 3, capture of water vapor and dust in the exhaust gas cooling device 14, and washing oil in the oil scrubber 4 Extraction of polychlorinated biphenyls, neutralization of organic acids in the alkali washing device 5, decomposition of polychlorinated biphenyls in the dehalogenation treatment device 6, hydration of unconsumed metallic sodium in the hydration tank 15, oil-water separation The operations and actions such as the reuse of the later cleaning oil in the oil scrubber 4 and the reuse in the alkaline cleaning apparatus 5 of the alkaline water after the oil-water separation are the same as those in the first embodiment, and the description thereof is omitted.
[0051]
Also in this embodiment, the polychlorinated biphenyl in the contaminated bottom mud to be treated is not discharged out of the system at all and is completely decomposed as in the first embodiment. In addition, since the liquid separated by the solid-liquid separator 1 is not processed by the reverse osmosis membrane, but is processed by the oxidative decomposition apparatus 17, the ocean containing a large amount of NaCl and the bottom mud of the estuary and the like are processed. In addition, there is no processing cost or insufficient processing.
[0052]
(Embodiment 3)
In the present embodiment, as shown in FIG. 4, a solvent extraction device 18 is used instead of the sand filtration device 2 of the first embodiment. The solvent extraction device 18 is supplied with processing oil (trans oil) and mixed with oil and water. After the oil / water mixing, the polychlorinated biphenyl contained in the separated liquid from the solid-liquid separating apparatus is extracted into the treated oil and supplied to the alkali cleaning apparatus 5.
[0053]
Then, the organic acid in the oil is neutralized together with the cleaning oil extracted by the oil scrubber 4, and the polychlorinated biphenyl in the treated oil is decomposed together with the polychlorinated biphenyl in the cleaning oil by the dehalogenation treatment device 6 in the subsequent stage. .
[0054]
On the other hand, a pressure flotation treatment device 19 is provided at the subsequent stage of the solvent extraction device 18, and the solvent extraction treated water after oil-water separation is supplied to the pressure flotation treatment device 19 and separated by pressure flotation. The separated water is discharged out of the system, but a part thereof is supplied to the hydration tank 15 and reused as water for hydration. The SS generated in the pressure levitation device is retransmitted at the entrance of the solid-liquid separator and processed again. Further, an ultrafiltration membrane device can be used in place of the pressure levitation device. In this case, the concentrated liquid is retransmitted to the inlet side of the solid-liquid separator and processed again.
[0055]
Decomposition of polychlorinated biphenyl by heat treatment in the reduction heat treatment device 3, capture of water vapor and dust in the exhaust gas cooling device 14, extraction of polychlorinated biphenyl into washing oil in the oil scrubber 4, organic in the alkali washing device 5 Neutralization of acid, decomposition of polychlorinated biphenyl in dehalogenation treatment device 6, hydration of unconsumed metallic sodium in hydration tank 15, reuse of cleaning oil in oil scrubber 4 after oil-water separation, oil water Respective operations and actions such as reuse in the alkaline cleaning apparatus 5 after separation are the same as those in the first embodiment, and a description thereof will be omitted.
[0056]
Also in this embodiment, the polychlorinated biphenyl in the contaminated bottom mud to be treated is not discharged out of the system at all and is completely decomposed as in the first embodiment. In addition, since the liquid separated by the solid-liquid separation device 1 is not treated by the reverse osmosis membrane but by the solvent extraction device 18, the ocean and estuary bottom mud containing a large amount of NaCl and the like are treated. In addition, there is no processing cost or insufficient processing.
[0057]
(Embodiment 4)
In the present embodiment, as shown in FIG. 5, a coagulating sedimentation device 20 is used instead of the sand filtration device 2 of the first embodiment. The coagulating sedimentation apparatus 20 is supplied with an organic polymer coagulant to perform coagulation sedimentation. The solid matter after the coagulation sedimentation is returned to the solid-liquid separator 1 and processed again.
[0058]
In this embodiment, the oxidative decomposition apparatus 17 is provided in the subsequent stage of the coagulation sedimentation apparatus 20, the supernatant liquid after the coagulation precipitation is supplied to the oxidative decomposition apparatus 17, and polychlorinated biphenyl is contained in the supernatant liquid. If so, polychlorinated biphenyl is decomposed by oxidative decomposition by blowing ozone or adding hydrogen peroxide.
[0059]
A part of the supernatant after the coagulation sedimentation is supplied to the exhaust gas treatment device 14, and a part of the treated water after the treatment in the oxidative decomposition device 17 is supplied to the hydration tank 15.
[0060]
In this embodiment, since an organic polymer flocculant is used instead of an inorganic flocculant such as polyaluminum chloride, there is no possibility that the metal element remains in the bottom mud during the reduction heat treatment.
In addition, an activated carbon device or an ultrafiltration membrane device can be used instead of the oxidative decomposition treatment device. Moreover, since the process about the concentrate in this case and the activated carbon after contamination is the same as that of the case of Embodiment 1 and Embodiment 2, the description is abbreviate | omitted.
[0061]
Decomposition of polychlorinated biphenyl by heat treatment in the reduction heat treatment device 3, capture of water vapor and dust in the exhaust gas cooling device 14, extraction of polychlorinated biphenyl into washing oil in the oil scrubber 4, organic in the alkali washing device 5 Neutralization of acid, decomposition of polychlorinated biphenyl in dehalogenation treatment device 6, hydration of unconsumed metallic sodium in hydration tank 15, reuse of cleaning oil in oil scrubber 4 after oil-water separation, oil water Respective operations and actions such as reuse in the alkaline cleaning apparatus 5 after separation are the same as those in the first embodiment, and a description thereof will be omitted.
[0062]
Also in this embodiment, the polychlorinated biphenyl in the contaminated bottom mud to be treated is not discharged out of the system at all and is completely decomposed as in the first embodiment. In addition, the liquid separated by the solid-liquid separation device 1 is not treated by the reverse osmosis membrane, but by the coagulation sedimentation device 20, so that the ocean containing a large amount of NaCl, the bottom mud of the estuary, and the like are treated. The processing cost is not increased or the processing is not insufficient.
[0063]
(Other embodiments)
In the above embodiment, the alkali cleaning device 5 is provided, and the water after oil-water separation containing sodium hydroxide is returned to the alkali cleaning device 5 for neutralization in the cleaning oil. It is also possible to directly return the water after oil-water separation to the oil scrubber 4 and neutralize the organic acid with the oil scrubber 4. If it does in this way, the neutralization process in the alkali cleaning apparatus 5 can be skipped.
[0064]
Furthermore, the metallic sodium used as the one for causing the decomposition reaction of polychlorinated biphenyl in the dehalogenation treatment apparatus 6 of the above embodiment has an advantage that it is inexpensive and generally easily available. It is also possible to use metal strontium, metal lithium or an alloy thereof. That is, a dispersant in which an alkali metal is dispersed in a dispersion medium such as oil may be used.
[0065]
Furthermore, although the case where polychlorinated biphenyl was treated was described in the above embodiment, the type of the organic halogen compound to be treated is not limited to the polychlorinated biphenyl of the above embodiment, for example, dioxin It may be.
[0066]
Moreover, pesticides, such as coplanar PCB, DDT, and BHC, may be sufficient.
Here, the coplanar PCB is an isomer of PCB which has no chemical substitution at the ortho position (2, 2 ′, 6 and 6 ′) in its chemical structure, and a tetrachloride having only one or two. Some of the above isomers are PCBs having a coplanar structure (coplanar), which are more toxic than ordinary PCBs and exhibit actions similar to those of dioxins.
[0067]
In short, it is only necessary that the soil to be treated contains an organic halogen compound.
[0068]
In the present invention, sludge mainly means marine and estuarine sludge and bottom mud containing a large amount of salt such as NaCl, but is not limited to this, and widely includes sludge-like substances contaminated with organic halogen compounds, For example, it is possible to apply the present invention to things such as contaminated soil.
[0069]
【The invention's effect】
As described above, the present invention solid-liquid separates contaminated bottom mud contaminated with an organic halogen compound, decomposes the organic halogen compound by heating the separated solid content in a reducing atmosphere, and in a reducing atmosphere. The organic halogen compound contained in the exhaust gas is supplied to the oil scrubber by heating, and the oil extracted by the oil scrubber is alkali washed, the organic halogen compound in the oil after alkali washing is decomposed with an alkali metal, and Since the liquid separated by the solid-liquid separation is for removing and removing organic halogen compounds in the liquid by water treatment means other than reverse osmosis membranes, no organic halogen compounds in the contaminated bottom mud to be treated are present. There is an effect that it is not discharged outside the system.
[0070]
In particular, since the organic halogen compound in the solid content separated by solid is decomposed by heating in a reducing atmosphere and decomposed by an alkali metal, there is an effect that the organic halogen compound can be completely decomposed. Further, since the liquid or solid containing the organic halogen compound generated by the water treatment means is treated again, there is an effect that no abandoned material containing the organic halogen compound is discharged from the system.
[0071]
In addition, since the oil extracted with the oil scrubber is washed with alkali, the organic acid contained with the organic halogen compound can be neutralized. As a result, the consumption of alkali metal in the subsequent dehalogenation treatment apparatus There is an effect that can be reduced.
[0072]
More importantly, since the liquid separated by the solid-liquid separator is processed by means other than reverse osmosis membranes, reverse osmosis membranes should be used when treating oceans and estuary mud containing a large amount of NaCl. There is an effect that the processing cost is not required as in the case of using, or the processing is not insufficient.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a purification apparatus for contaminated bottom mud contaminated with an organic halogen compound as one embodiment.
FIG. 2 is a schematic block diagram of a reduction heating device in the purification device.
FIG. 3 is a schematic block diagram of a purification apparatus for contaminated bottom mud contaminated with an organic halogen compound according to another embodiment.
FIG. 4 is a schematic block diagram of a purification apparatus for contaminated bottom mud contaminated with an organic halogen compound according to another embodiment.
FIG. 5 is a schematic block diagram of a purification apparatus for contaminated bottom mud contaminated with an organic halogen compound according to another embodiment.
FIG. 6 is a schematic block diagram of a conventional processing system.
FIG. 7 is a schematic block diagram of a conventional processing system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Solid-liquid separator 2 ... Sand filtration apparatus 3 ... Reduction heating apparatus 4 ... Oil scrubber 5 ... Alkaline washing apparatus 6 ... Dehalogenation processing apparatus 14 ... Exhaust gas cooling apparatus 17 ... Oxidation decomposition apparatus 18 ... Solvent extraction apparatus 20 ... Aggregation Precipitation equipment

Claims (8)

The sludge contaminated with the organic halogen compound is separated into solid and liquid, and the separated solid is heated in a reducing atmosphere to decompose the organic halogen compound, and the organic halogen contained in the exhaust gas by heating in the reducing atmosphere. The compound is supplied to the oil scrubber, the oil in the oil scrubber is washed with alkali, the organic halogen compound in the oil after alkali washing is decomposed with an alkali metal, and the liquid separated by the solid-liquid separation is reverse osmosis A method for purifying sludge contaminated with an organic halogen compound, characterized in that the organic halogen compound in the liquid is separated and removed by water treatment means other than a membrane. The water treatment means other than the reverse osmosis membrane is any one of sand filtration, oxidative decomposition means such as ozone / hydrogen peroxide, solvent extraction method and coagulation sedimentation method. A method for purifying sludge contaminated with an organohalogen compound according to claim 1. 3. The organic halogen compound according to claim 2, wherein the second water treatment means is any one of pressurized flotation treatment, activated carbon treatment, ultrafiltration membrane treatment, and oxidative decomposition treatment with ozone / hydrogen peroxide. To purify sludge contaminated with water. The water vapor and dust contained in the exhaust gas are captured by cooling before the organic halogen compound contained in the exhaust gas is supplied to the oil scrubber by heating in a reducing atmosphere. To clean sludge contaminated with various organic halogen compounds. Solid-liquid separation device (1) for solid-liquid separation of sludge contaminated with organic halogen compounds, and the liquid separated by the solid-liquid separation device (1) is treated with organic halogen in the liquid by means of water treatment other than reverse osmosis membrane. A means for separating and removing the compound, a reduction heat treatment apparatus (3) for decomposing an organic halogen compound in the solid content by heating the solid content separated by the solid-liquid separator (1) in a reducing atmosphere; An oil scrubber (4) for supplying an organic halogen compound contained in the exhaust gas by heating in the reduction heat treatment apparatus (3) and collecting the organic halogen compound in the oil; and an oil content of the oil scrubber (4) And an alkali cleaning means for alkali cleaning, and a dehalogenation treatment apparatus (6) for decomposing an organic halogen compound in the oil after alkali cleaning with an alkali metal. Purification equipment for sludge contaminated with organic halogen compounds. The water treatment means other than the reverse osmosis membrane is a sand filtration device (2), an oxidative decomposition device (17) using ozone, hydrogen peroxide, etc., a solvent extraction device (18), or a coagulation sedimentation device (20). The apparatus for purifying sludge contaminated with an organic halogen compound according to claim 5, wherein a second water treatment means is provided. The second water treatment means is one of a pressure flotation device, an activated carbon device, an ultrafiltration membrane device, an oxidative decomposition device using ozone, hydrogen peroxide, etc., and is contaminated with an organic halogen compound. Sludge purification equipment. Claims provided with an exhaust gas cooling device (14) for capturing water vapor and dust contained in the exhaust gas by cooling before supplying the organic halogen compound contained in the exhaust gas to the oil scrubber by heating in a reducing atmosphere. Item 8. A device for purifying sludge contaminated with an organic halogen compound according to any one of Items 5 to 7.

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