JP6906376B2 - Purification method for PCB processing facility - Google Patents

Description

The present invention relates to a method for purifying a PCB treatment facility, and more particularly to a method for purifying a PCB treatment facility in which the PCB concentration of the partition member is reduced to a reference value or less by scraping and removing the partition member for partitioning the PCB treatment facility.

Since PCB (polychlorinated biphenyl), which is a nonflammable insulator, is harmful to the human body, it is stipulated that it should be detoxified within the legal period. After detoxifying all PCB contaminants existing in Japan, the PCB treatment facility will be dismantled, but the partition members such as walls, floors, and ceilings in the PCB treatment facility will be made into air containing PCB. It is necessary to clean the compartment members before dismantling the PCB treatment facility because they are exposed or have adhered to the PCB leaked from the PCB contaminants.

The method for purifying a PCB treatment facility in Patent Document 1 is to form a coating film on the surface of a concrete wall with a liquid paint, and scrape the surface together with the cured coating film to a depth of 5 to 10 mm to remove PCB. be. As a result, it is described that the PCB that has entered the fine recesses of the concrete wall can be attached to the coating film and removed.

Japanese Unexamined Patent Publication No. 2012-187456

For example, in the case of a section member made of concrete, PCB may permeate until it reaches a certain depth from the surface. In the method for purifying a PCB treatment facility described in Patent Document 1, although PCB existing in a recess near the surface of a partition member can be removed by adhering to a coating film, PCB that has penetrated deep into the partition member can be reliably removed. There is room for improvement as it is difficult to remove. Moreover, it is complicated to form a coating film on the entire surface of the partition member.

Therefore, there is a demand for a purification method for a PCB processing facility that can reliably remove PCBs of partition members while being a simple method.

The purification method of the PCB processing facility is to set a feature point for each predetermined area of the partition member that partitions the inside of the PCB treatment facility, and scrape off the feature point for each first distance set in the thickness direction of the partition member. The step, the measurement step of measuring the PCB concentration of the scraped portion for each first distance in the section member, and the second distance in the thickness direction from the surface of the section member by adding the first distance. A specific step of setting and specifying the second distance corresponding to the scraped portion where the PCB concentration measured in the measuring step is equal to or less than the reference value, and the second distance from the surface in the predetermined area. It is a point provided with a removal step of scraping and removing the partition member until the third distance obtained by subtracting the first distance is reached.

In this method, the PCB concentration of the scraped portion is measured for each first distance (D1) at the feature point provided in the predetermined area of the partition member. For this reason, the inconvenience that the cutting part of the first distance (D1) and the cutting part of the next first distance (D1) are mixed and the PCB concentration for each cutting part cannot be measured accurately is solved. can. As a result, it becomes possible to accurately measure the PCB concentration of the scraped portion at the second distance (D2 = D1 × N) in which the first distance (D1) is added N times, and the PCB penetration depth is the second. The three distances (D3 = D2-D1) can be reliably specified.

Further, in the removing step, since the scraping is performed until the third distance (D3) is reached from the surface of the partition member in the predetermined area, it is possible to save the trouble of scraping while measuring the PCB concentration at each of a plurality of points. Further, in this method, since the second distance (D2) at which the PCB concentration is equal to or less than the reference value is specified, it is efficient without scraping deeper than necessary.

As described above, it has been possible to provide a purification method for a PCB processing facility that can reliably remove PCBs of partition members while being a simple method.

In another method, after the removal step, the partition member for the first distance is scraped off at a point different from the feature point, and the PCB concentration of the scraped portion for the first distance is equal to or less than the reference value. The point is that it is further provided with an analysis process for determining whether or not it is present.

Even if a characteristic point where the PCB concentration is assumed to be high is selected from the work history or the like in a predetermined area, there is a possibility that there is a point where the PCB concentration is even higher. As in this method, if the PCB concentration of the scraped portion for the first distance (D1) at a point different from the feature point is determined after scraping the partition member up to the third distance (D3), the PCB of the compartment member can be obtained. It can be removed more reliably.

It is a conceptual diagram of the purification method of the PCB processing facility which concerns on this embodiment. It is a purification flow chart.

Hereinafter, embodiments of the purification method for the PCB processing facility according to the present invention will be described with reference to the drawings. In the present embodiment, as an example of the purification method of the PCB treatment facility, a concrete wall WL (an example of a section member), a concrete floor WF (an example of a section member) or a concrete material that divides each controlled area of the PCB treatment facility. The case where the PCB of the ceiling WT (an example of a partition member) is removed will be described. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

As shown in FIG. 1, the inside of the PCB treatment facility includes a controlled area A in which the contamination level of the PCB is defined and a non-controlled area in which the PCB is not handled. In addition, the PCB processing facility is equipped with cleaning equipment (not shown), a plasma melting furnace, an activated carbon tank, and the like.

The controlled area A is composed of a high concentration controlled area having a PCB contamination level 3, a medium concentration controlled area A2 having a PCB contamination level 2, and a low concentration controlled area having a PCB contamination level 1. A high concentration control area with PCB contamination level 3 is an area that requires high level control because there is a possibility that the work environment will be contaminated by PCB under normal operation. The medium concentration control area A2 of PCB contamination level 2 is a target in which the work environment is not contaminated by PCB under normal operation, but high concentration PCB is indirectly handled (or the PCB is almost removed) in the work in the process. It is an area that requires proper management because it handles things in the work environment). The low concentration control area of PCB contamination level 1 is an area where the PCB in the process is sealed in the equipment, so that the working environment is not contaminated by the PCB under normal operation and can be dealt with with the minimum control.

In high-concentration control areas, PCB contaminants are sorted by type, and electrical equipment is disassembled in the glove box and packed in a container (not shown) consisting of, for example, a washing basket, drums, and pail cans. Change. Then, the PCB contaminants are detoxified by cleaning the cleaning basket with a solvent or putting the container into a plasma melting furnace. PCB contaminants are composed of electrical equipment (ballasts, transformers, capacitors, etc.), operating waste (work clothes, rubber gloves, waste cloth, etc.), pressure-sensitive copying paper, sludge, insulating oil, and the like.

In the medium concentration control area A2, the outside of the glove box (the inside is a high concentration control area), piping through which air or liquid containing PCB flows, equipment having a low PCB concentration, and the like are arranged. In the low concentration control area, sealing equipment, piping, etc. that contain liquid containing PCB are arranged. The non-controlled area is composed of an attic or a space between the controlled area A and the wall WL facing the outside. In addition, each controlled area A and non-controlled area is partitioned by a wall WL, a floor WF, or a ceiling WT.

The wall WL, floor WF or ceiling WT of the medium concentration control area A2 and the low concentration control area are made of concrete or the like. Further, the wall WL facing the outside of the uncontrolled area is composed of lightweight foam concrete (ALC) in which reinforcing bars are embedded.

Hereinafter, a method for removing PCB contained in the wall WL, floor WF, or ceiling WT of the medium concentration control area A2 will be described as an example.

In the medium concentration control area A2, PCB contaminants having a high PCB concentration are not actively handled, but the PCB concentration in the air is relatively high because the high concentration PCB is indirectly handled in the work in the process. Therefore, in the medium concentration control area A2, air containing PCB is sent to an exhaust treatment facility such as an activated carbon tank to be purified by an exhaust fan (not shown). The wall WL, floor WF, or ceiling WT of the medium concentration control area A2 is opened for periodic inspection, such as a strainer provided when air including PCB permeates the wall WL, floor WF, or ceiling WT and permeates the PCB. PCB leaks from the equipment that needs it, and PCB adheres to it. Therefore, among the wall WL, the floor WF, and the ceiling WT, a portion having a high PCB concentration can be specified from the arrangement location and usage method of the equipment.

As shown in FIGS. 1 and 2, a predetermined area from which the PCB is removed is set in the medium concentration control area A2. The predetermined area may be set by the working area per day, or may be divided by a predetermined predetermined area. Next, the feature point P1 in which the PCB concentration is assumed to be the highest is selected from the predetermined areas. This feature point P1 is comprehensively selected based on the location of the equipment, the method of use, the work history, and the like.

Next, the feature point P1 is scraped off every first distance D1 (for example, 5 mm) set in the thickness direction of the wall WL, the floor WF, or the ceiling WT (cutting step). This grinding step is performed using a grinding machine 1 having a grindstone, a file, a wire brush, and the like, and a vacuum suction device C that sucks grinding powder (cutting portion) generated by scraping concrete. The exhaust gas containing the grinding powder scraped off by the grinding machine 1 is sucked by the vacuum suction device C, and the grinding powder collected by filtering the exhaust gas passing through the pipe 3 is stored in the dust collecting unit 2. The exhaust gas from which the grinding powder is separated is detoxified by an exhaust treatment facility such as an activated carbon tank.

Next, the PCB concentration of the grinding powder (cutting site) for the first distance D1 stored in the dust collecting unit 2 is measured (measurement step). Next, it is determined whether or not the PCB concentration of the grinding powder is equal to or less than the reference value (for example, 0.03 mg / L-test solution, which is the graduation standard of PCB), and the above-mentioned scraping step is performed until the PCB concentration becomes equal to or less than the reference value. And the measurement process is repeated N times. Next, the first distance D1 is added N times to specify the second distance D2 (D1 × N) corresponding to the grinding powder (cutting site) whose PCB concentration is equal to or less than the reference value (specific step). In the dust collecting unit 2 of the present embodiment, the dust collecting bag is removed when the grinding powder for the first distance D1 is stored, and a new dust collecting bag is installed in the next scraping process. It is supposed to be. As a result, the grinding powder at the first distance D1 and the grinding powder at the next first distance D1 do not mix with each other.

Next, the entire wall WL, floor WF, or ceiling WT in the predetermined area is scraped off using the grinder 1 until the third distance D3 (D2-D1 = D1 × (N-1)) is reached from the surface (D2-D1 = D1 × (N-1)). Removal process). The removed grinding powder is refilled in a container and detoxified in a plasma melting furnace. After reducing the PCB concentration of the removed grinding powder to below the standard value in a cleaning facility, the PCB oil may be chemically treated, or it may be taken out of the PCB treatment facility and properly treated in a different PCB treatment facility. The detoxification method is not particularly limited.

Next, at the analysis point P2 different from the feature point P1 in the predetermined area, the wall WL, floor WF or ceiling WT for the first distance P1 is scraped by the grinding machine 1, and the PCB concentration of the grinding powder (cutting site) is the reference value. It is determined whether or not it is as follows (analysis step). The analysis point P2 is preferably a point where the PCB concentration is assumed to be the second highest after the feature point P1.

If the PCB concentration of the grinding powder is less than the reference value in the analysis step, the PCB removal in the predetermined area is completed. On the other hand, if the PCB concentration of the grinding powder is higher than the reference value in the analysis process, the wall WL, floor WF or ceiling WT for the first distance D1 below the third distance D3 is scraped off by the grinding machine 1 at the analysis point P2. , Repeat N times until the PCB concentration of the grinding powder (cutting site) becomes equal to or less than the reference value. Next, the entire wall WL, floor WF, or ceiling WT in the predetermined area is scraped off using the grinder 1 until the third distance D3 (D2-D1 = D1 × (N-1)) is reached from the surface. The removed grinding powder is refilled in a container and detoxified in a plasma melting furnace. After reducing the PCB concentration of the removed grinding powder to below the standard value in a cleaning facility, the PCB oil may be chemically treated, or it may be taken out of the PCB treatment facility and properly treated in a different PCB treatment facility. The detoxification method is not particularly limited.

Next, at the analysis point P2'(preferably the point where the PCB concentration is assumed to be the third highest) different from the feature point P1 and the analysis point P2 in the predetermined area, the wall WL for the first distance P1 minute, The floor WF or ceiling WT is scraped off with the grinder 1. After that, the same operation as that at the analysis point P2 described above is repeated when the PCB concentration of the grinding powder is below the reference value.

In this way, at the feature point P1 provided in the predetermined area of the wall WL, the floor WF, or the ceiling WT, the PCB concentration of the ground powder scraped off is measured for each first distance D1. Therefore, it is possible to eliminate the inconvenience that the grinding powder at the first distance D1 and the grinding powder at the next first distance D1 are mixed and the PCB concentration for each grinding powder cannot be accurately measured. As a result, it becomes possible to accurately measure the PCB concentration of the grinding powder at the second distance D2 (D1 × N) obtained by adding the first distance D1 N times, and the third distance D3 (the depth at which the PCB permeates) (3) D2-D1) can be reliably identified.

Further, in the removing step, since the scraping is performed from the surface of the wall WL, the floor WF or the ceiling WT in the predetermined area until the third distance D3 is reached, it is possible to save the trouble of scraping while measuring the PCB concentration at each of a plurality of points. Further, in the present embodiment, since the second distance D2 in which the PCB concentration is equal to or less than the reference value is specified, it is efficient without scraping deeper than necessary.

On the other hand, even if the feature point P1 which is assumed to have a high PCB concentration is selected from the work history or the like in a predetermined area, there is a possibility that there is a point where the PCB concentration is even higher. If the PCB concentration of the grinding powder for the first distance D1 at the analysis point P2 different from the feature point P1 is determined after scraping the wall WL, the floor WF or the ceiling WT up to the third distance D3 as in the present embodiment. PCBs on wall WL, floor WF or ceiling WT can be removed more reliably.

[Other Embodiments]
(1) If the feature point P1 having the highest PCB concentration in the predetermined area can be reliably selected, the analysis step in the above-described embodiment may be omitted. Further, the analysis step may not be executed at a plurality of analysis points P2, P2', ..., But may be executed only at one analysis point P2.
(2) In the above-described embodiment, an example in which the same grinder 1 is used as a device for scraping the wall WL, floor WF, or ceiling WT in the scraping step and the removing step is shown, but small grinding is performed in the scraping step. Machine 1 may be used, and a large-scale grinder or excavator may be used in the removal step, and the method is not particularly limited. Further, the grinding machine 1 may be any device as long as it can collect the scraped portion.
(3) The partition member of the above-described embodiment is not limited to the wall WL, the floor WF, or the ceiling WT, and may be any partition member as long as it is a member in which PCB has penetrated.

INDUSTRIAL APPLICABILITY The present invention can be used as a purification method for a PCB processing facility in which a partition member for partitioning the inside of the PCB processing facility is scraped off and removed.

D1 1st distance D2 2nd distance D3 3rd distance P1 Feature point P2 Analysis point (point different from feature point)
WF floor (partition member)
WL wall (partition member)
WT ceiling (partition member)

Claims (2)

A feature point where the PCB concentration is assumed to be the highest is set for each predetermined area of the partition member that partitions the inside of the PCB processing facility, and the feature point is scraped off for each first distance set in the thickness direction of the partition member. Shaving process and
A measurement step of measuring the average value of the PCB concentration of the scraped portion for each first distance in the section member, and
By adding the first distance, the second distance in the thickness direction from the surface of the partition member is set, and the average value of the PCB concentration measured in the measurement step is equal to or less than the reference value. A specific step of identifying the second distance to which the corresponding first distance was last added, and
A method for purifying a PCB processing facility, comprising a removal step of scraping and removing the partition member in the predetermined area until a third distance obtained by subtracting the first distance from the surface to the second distance is reached. After the removal step, the partition member for the first distance is scraped at a point different from the feature point in the predetermined area , and the average value of the PCB concentration of the scraped portion for the first distance is the reference value. Further equipped with an analysis process to determine whether or not the following
When it is determined in the analysis step that the average value of the PCB concentration exceeds the reference value, the PCB concentration is further scraped from the second distance at each first distance at the different points, and the scraped portion of the first distance is scraped. The purification method for a PCB processing facility according to claim 1, wherein the analysis step of determining whether or not the average value of the PCB concentration is equal to or less than the reference value is repeated until the average value of the PCB concentration becomes equal to or less than the reference value.

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