JP2013234948A - Removal device of contaminant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost removal device of a contaminant, which is easier to handle than a conventional one, and a decontamination method for removing the contaminant from water flowing through a channel.SOLUTION: A removal device of a contaminant includes: a plurality of porous concrete blocks having aggregates whose surfaces are coated with zeolite; and a block fixing unit supporting the plurality of porous concrete blocks in a channel through which the contaminant flows. At least one of the dimension of the aggregates and the porosity which is a ratio of voids formed between the aggregates differs between the porous concrete blocks.

Description

  The present invention relates to a contaminant removal apparatus.

  Water-permeable porous concrete (for example, porous concrete) is capable of growing plants and microorganisms in voids, and is used as a concrete for greening (for example, see Patent Document 1). Porous concrete is also used as a sound absorbing material because of its large voids and sound absorbing properties (see, for example, Patent Document 2).

  Moreover, as a river purification device, there is a device using a triangular block purification block in which aggregate and zeolite particles are combined using cement as a binder (see, for example, Patent Document 3).

JP 2004-316229 A JP 2003-227297 A JP-A-8-276198

  There are two possible forms of radioactively contaminated water: ionized cesium and cesium adsorbed on clay material. As a technique for removing ionized cesium, there is a technique for purifying water through a filter material by ion exchange using zeolite mineral or Prussian blue. In addition, as a technique for removing cesium adsorbed on clay or the like, there is a technique for purifying water by forming flocs using various coagulating precipitants and performing turbid separation.

  Here, water polluted by pollutants such as radioactive substances and heavy metals flows through water channels and is discharged into rivers and the sea. If the radioactive substance can be removed from the water flowing through the water channel, the contaminated water can be prevented from being discharged into the river or the sea. However, since the water channel is installed in a wide range, it is necessary to develop a purification technique that is simpler and less expensive than conventional methods in order to remove the contaminants from the water flowing through the water channel.

  In view of the above problems, an object of the present invention is to provide a purification technique that is easier and cheaper to handle than conventional ones and that removes contaminants from water flowing through a water channel.

  In the present invention, in order to solve the above problems, a plurality of porous concrete blocks having different porosity are arranged side by side in a water channel.

  Specifically, the present invention is an apparatus for removing contaminants, which is a porous concrete block including an aggregate whose surface is coated with zeolite, and is formed between the size of the aggregate and the aggregate. A plurality of porous concrete blocks that are different from each other in at least one of the void ratios, and a block that supports the plurality of porous concrete blocks in a water channel through which water contaminated with the contaminant flows. A fixing unit.

In the pollutant removal apparatus according to the present invention, the water pollutant flowing through the water channel is adsorbed or physically captured by the porous concrete block. Examples of pollutants include radioactive substances and heavy metals. Further, the contaminants that can be adsorbed or captured by the contaminant removal apparatus according to the present invention include those that are dissolved in water and ionized, and those that are adsorbed on clay and the like and exist as suspended substances. Porous concrete blocks are a combination of multiple blocks with different aggregate dimensions and void ratios, and even when the flow rate and flow rate of water and the type and amount of contaminants contained in water are different, they can effectively remove contaminants. Can be adsorbed and captured. Further, the plurality of porous concrete blocks are supported by the fixed unit, and are not separated by the flow of water, and can be easily taken out from the water channel. Moreover, when the adsorption / capturing performance of some porous concrete blocks among the plurality of porous concrete blocks is lowered, only the porous concrete block having the lowered adsorption / trapping performance can be replaced. The porous water concrete block can be made of porous concrete including, for example, zeolite and aggregate (for example, crushed stone). Therefore, compared with the conventional technology that purifies water through the filter material by ion exchange with zeolite mineral or Prussian blue, and the conventional technology that purifies water by forming flocs using a coagulant precipitation agent Thus, it is possible to provide a contaminant removal device that is easy to handle and inexpensive. The porous concrete block is not limited to porous concrete blocks as long as it has voids and desirably can control the proportion of these voids. In addition, the water channel should just have the water polluted with the pollutant, and a drainage ditch | gutter and a water collection tank are illustrated by the water channel.

  In the pollutant removal device according to the present invention, the plurality of porous concrete blocks may have an aggregate size of the upstream porous concrete block that is smaller than an aggregate size of the downstream porous concrete block in the water flow. You may enlarge it. In the plurality of porous concrete blocks, the porosity of the upstream porous concrete block in the water flow may be larger than the porosity of the downstream porous concrete block. By making the aggregate size and porosity of the porous concrete block on the upstream side larger than that on the downstream side, it is possible to more effectively adsorb and trap the contaminants.

  Further, in the pollutant removal device according to the present invention, the plurality of porous concrete blocks may include, among the aggregate size and porosity of the porous concrete block, from the upstream side toward the downstream side in the water flow. At least one of them may change stepwise. For example, an aspect in which the upstream aggregate size and porosity are maximized is exemplified. Thereby, a contaminant can be adsorbed and captured more effectively. In addition, it is assumed that the adsorption / capture performance of the upstream porous concrete block is deteriorated the fastest, but in this case, only the porous concrete block having the lowered adsorption / capture performance can be replaced.

  Here, in the contaminant removal apparatus according to the present invention, the block fixing unit may be configured to hold the porous concrete block and have a plurality of holding portions provided in a plurality of stages in the vertical direction.

  In the water channel, there is a possibility that the adsorption / capturing performance of the porous concrete block to be arranged varies depending on the position in the vertical direction of the water channel. For example, since water always flows at the bottom of the water channel, the adsorption / capturing performance of the porous concrete block on the bottom side of the water channel is most likely to deteriorate the fastest. In view of such a problem, the present invention holds the porous concrete block by a holding portion provided in a plurality of stages in the vertical direction. As a result, the porous concrete block located under the moved holding part can be easily exchanged by moving the holding part located on the upper surface side of the porous concrete block to be exchanged upward.

The block fixing unit holds the porous concrete block, a plurality of holding portions provided in a plurality of stages in the vertical direction, a hinge portion to which one end of the plurality of holding portions is connected, and the hinge portion includes It is good also as a structure which has a support part which is provided and supports the said several holding | maintenance part pivotably on the said hinge part. In the present invention, the porous concrete block is held by a holding portion provided in a plurality of stages in the vertical direction, and the holding portion can be rotated about the hinge portion as an axis. As a result, the porous concrete block located under the lifted holding part can be easily replaced by rotating and lifting the holding part located on the upper surface side of the porous concrete block to be replaced around the hinge part. can do. That is, by lifting only one side, the porous concrete block located under the lifted holding portion can be easily replaced.

  According to the present invention, it is possible to provide a purification technique that is easier and cheaper to handle than conventional ones and that removes contaminants from water flowing through a water channel.

1 is a perspective view of a contaminant removal apparatus according to a first embodiment. The image figure explaining a mode that the contaminant removal apparatus which concerns on 1st embodiment removes a contaminant is shown. The modification of the contaminant removal apparatus which concerns on 1st embodiment is shown. The top view of the contaminant removal apparatus which concerns on 2nd embodiment is shown. The side view of the contaminant removal apparatus which concerns on 2nd embodiment is shown. In the pollutant removal apparatus according to the second embodiment, an artificial zeolite block is exchanged. The top view of the contaminant removal apparatus which concerns on 3rd embodiment is shown. The side view of the contaminant removal apparatus which concerns on 3rd embodiment is shown. A mode that a concrete block is replaced | exchanged in the contaminant removal apparatus which concerns on 3rd embodiment is shown.

Next, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a case where water containing suspended radioactive material adsorbed on ionized radioactive cesium (C _S ) and clay is purified as an example will be described. However, the embodiment described below is an example for carrying out the present invention, and the present invention is not limited to the mode described below. For example, the contaminants include heavy metals.

<First embodiment>
<< Configuration >>
A pollutant removal apparatus 1 (hereinafter also simply referred to as a removal apparatus) according to the first embodiment includes a plurality of artificial zeolite blocks 2 (corresponding to the porous concrete block of the present invention) and a basket 10. ing. The removal apparatus 1 can be installed in a drainage gutter or a water collecting tank. FIG. 1 shows a state in which the removing device 1 is installed in the drainage side groove 3. By installing the removal device 1 in the drainage gutter 3 or the water collecting basin 4 (an example of installation in the water collecting basin will be described in the second embodiment), radioactive pollutants flowing in from rain, washing water, etc. The artificial zeolite block 2 can be adsorbed and captured. As a result, it is possible to suppress the accumulation and diffusion of pollutants in the drain side gutter 2 and the catchment trough 3.

  The artificial zeolite block 2 is formed by covering the surface of the aggregate with a paste-like binder mixed with zeolite and solidifying the aggregates with the binder. Examples of the aggregate include natural crushed stone, natural zeolite aggregate, and artificial zeolite granulated product obtained by granulating powdery artificial zeolite. The particle size of the aggregate can be set to 2 mm or more, for example.

The artificial zeolite block 2 according to the first embodiment is a quadrangular prism. The artificial zeolite block 2 can be, for example, 10 cm × 10 cm × 20 cm. The shape and size of the artificial zeolite block 2 can be appropriately designed in consideration of the adhesion with the adjacent artificial zeolite block 2, the shape and size of the drain side groove and the water collecting basin, the amount of water, and the like. For example, the artificial zeolite block 2 can have a hollow cylindrical shape, a triangular prism shape, an L shape, or a plate shape.

  The removal device 1 according to the first embodiment is constituted by three types of artificial zeolite blocks 2 having different aggregate dimensions. As for the first artificial zeolite block 21, No. 5 crushed stone (size: 20 mm to 13 mm) is used as an aggregate, and the porosity indicating the ratio of voids in the first artificial zeolite block 21 is 20%. As for the second artificial zeolite block 22, No. 6 crushed stone (size: 13 mm to 5 mm) is used as an aggregate, and the porosity indicating the ratio of the voids in the second artificial zeolite block 22 is 20%. The third artificial zeolite block 23 uses No. 7 crushed stone (size: 5 mm to 2.5 mm) as an aggregate, and the porosity of the third artificial zeolite block 23 indicating the ratio of voids is 20%. Then, the first artificial zeolite block 21 is vertically installed on the upstream side, the third artificial zeolite block is vertically installed on the downstream side, and the second artificial zeolite block 22 is 3 in the meantime. It is installed vertically. In addition, all the artificial zeolite blocks 2 are installed without gaps.

  The basket 10 corresponds to the fixing unit of the present invention, and fixes a plurality of artificial zeolite blocks 2. The basket 10 is made of a wire mesh and has a size that can accommodate a plurality of artificial zeolite blocks 2.

<< Action and effect >>
FIG. 2 is an image diagram for explaining how the contaminant removal apparatus according to the first embodiment removes (adsorbs / captures) the contaminant. The arrows in FIG. 2 indicate the flow of contaminated water. As shown in FIG. 2, water contains ionized radioactive cesium and radioactive cesium adsorbed on clay and the like, and is suspended as a suspended substance. The contaminated water sequentially passes through the first artificial zeolite block 21, the second artificial zeolite block 22, and the third artificial zeolite block 23. The ionized radioactive cesium is adsorbed on the paste-like zeolite coated on the surface of the aggregate. Further, voids are formed between the aggregates, and radioactive cesium (suspended material) adsorbed on clay or the like is trapped and trapped in the voids. That is, ionized radioactive cesium contained in water as a pollutant or radioactive cesium in a suspended substance passes through the artificial zeolite block 2 so that it is physically captured in the artificial zeolite block 2 and is pasty. The zeolite is ion-exchanged and adsorbed. As a result, the contaminated water is purified.

  The removal device 1 according to the first embodiment is constituted by a plurality of artificial zeolite blocks 2 having different aggregate dimensions. Specifically, the aggregate size of the artificial zeolite block 2 gradually decreases in steps from the upstream side to the downstream side of the water flow. Therefore, the flow rate of water passing through the artificial zeolite block 2 gradually decreases, and the radioactive cesium adsorbed on the ionized radioactive cesium, clay, etc. can be more effectively adsorbed and captured. In addition, it is possible to capture according to the size of the contaminant. That is, a relatively large suspended substance (radioactive cesium adsorbed on clay or the like) is captured by the first artificial zeolite block 21 installed on the upstream side, and a relatively small contaminant is captured by the first artificial zeolite. It is captured by the second artificial zeolite block 22 or the third artificial zeolite block 23 installed on the downstream side of the block 21.

Further, for example, when the adsorption / capture performance of the first artificial zeolite block 21 installed on the upstream side is lowered, only the first artificial zeolite block 21 having the lowered adsorption / capture performance can be replaced.

  Further, the removal device 1 according to the first embodiment is formed by coating the surface of the aggregate with a paste-like binder mixed with zeolite and solidifying the aggregate covered with the paste-like zeolite with the binder. Conventional technology to purify water through filter materials and ion exchange using zeolite minerals or Prussian blue, and to purify water by forming flocs using a coagulating precipitant and turbid separation Compared with the technology, the handling becomes easier, and it can be provided at a lower cost than in the past.

<Modification>
FIG. 3 shows a modification of the contaminant removal apparatus according to the first embodiment. In the removal device 1 according to the modification, the first artificial zeolite block 21, the second artificial zeolite block 22, and the third artificial zeolite block 23 are all composed of No. 5 crushed stone. However, the porosity of the first artificial zeolite block 21 is 25%, the porosity of the second artificial zeolite block 22 is 20%, and the porosity of the third artificial zeolite block 23 is 15%. Yes. The porosity can be changed by adjusting the ratio of the binder and the thickness of the pasty zeolite covering the aggregate. Also with the removal device 1 according to the modified example, the same effect as the removal device 1 according to the first embodiment described above can be obtained.

<Second embodiment>
<< Configuration >>
FIG. 4 is a top view of the contaminant removal apparatus according to the second embodiment. FIG. 5 shows a side view of the contaminant removal apparatus according to the second embodiment. As shown in FIGS. 4 and 5, the removal device 1 </ b> A according to the second embodiment includes a plurality of artificial zeolite blocks 2, a plurality of vertical stages, a holding member 5 that holds the artificial zeolite blocks 2, and an artificial zeolite block 2 and a frame 7 that supports the suspension 6. In 2nd embodiment, the case where the removal apparatus 1A is installed in the water collecting tank 4 is demonstrated to an example.

  The plurality of artificial zeolite blocks 2 are composed of three types of artificial zeolite blocks 2 having different aggregate dimensions as in the first embodiment. However, in the second embodiment, the artificial zeolite block 2 is placed horizontally at the bottom of the catchment basin 4 so that the longitudinal direction of the artificial zeolite block 2 and the direction in which water flows (longitudinal direction of the drainage side groove) are orthogonal to each other. Three types of artificial zeolite blocks 2 of the same type are stacked in the vertical direction. Specifically, the first artificial zeolite block 21 is stacked in three stages in the vertical direction on the upstream side, and the third artificial zeolite block 23 is stacked in the vertical direction on the downstream side, while the second artificial zeolite block 22 is stacked therebetween. Are stacked vertically. In the horizontal direction, three types of artificial zeolite blocks 2 are arranged without gaps, and in the vertical direction, holding members 5 are interposed between the artificial zeolite blocks 2.

  The holding member 5 corresponds to the fixed unit of the present invention, is composed of two rod-like members arranged in parallel, and is provided in three stages in the vertical direction, and holds the artificial zeolite block 2 at each stage. In 2nd embodiment, although the holding member 5 is installed in parallel with the direction through which water flows, the direction of the holding member 5 is not specifically limited. The length of the holding member 5 is designed so that both ends extend from the artificial zeolite block 2 installed without a gap. Both ends of the holding member 5 are connected to a chain 8 that can be rolled up by a lifting tool 6.

The lifting tool 6 lifts the artificial zeolite block 2 by winding up the chain 8. By changing the holding member 5 for connecting the chain 8, the number of artificial zeolite blocks 2 to be lifted can be changed. For example, when the chain 8 is connected to the lower holding member 5, all three stages of the artificial zeolite block 2 are lifted. The hanging tool 6 is exemplified by a chain block. In the second embodiment, four lifting devices 6 are installed. However, a balance is used, and the lifting device 6 may be one device on the upstream side and the downstream side, for a total of two devices.

  The frame body 7 is installed so as to straddle the catchment basin 4 and supports the hanging tool 6. The frame body 7 includes a frame-shaped base portion 71 placed on the top end of the water collecting basin 4, four column portions 72 raised from the corners of the base portion 71, and the top portions of the four column portions 72. It is comprised by the frame-shaped beam part 73 connected to. The hanger 6 is connected to the beam portion 73 that traverses the catchment basin 4 among the frame-shaped beam portions 73.

<< How to replace an artificial zeolite block >>
FIG. 6 shows how the artificial zeolite block is replaced in the contaminant removal apparatus according to the second embodiment. First, the frame body 7 and the hanging tool 6 are installed above the artificial zeolite block 2 to be replaced. Next, the chain 8 is connected to the holding member 5. In FIG. 6A, a chain 8 is connected to the middle holding member 5. Next, the chain 8 is wound up by the lifting tool 6. In FIG. 6 (b), the middle and upper artificial zeolite blocks 2 are suspended. When the middle and upper artificial zeolite blocks 2 are lifted, the lower artificial zeolite blocks 2 are replaced. After the replacement, the middle and upper artificial zeolite blocks 2 are lowered. The frame body 7 and the hanging tool 6 are removed, and the replacement of the artificial zeolite block 2 is completed.

<< Action and effect >>
1 A of removal apparatuses which concern on 2nd embodiment have the following effects in addition to the effect of the removal apparatus 1 which concerns on 1st embodiment. In a water channel (for example, a water collecting trough 4 as in the second embodiment), the adsorption / trapping performance of the artificial zeolite block 2 arranged varies depending on the position in the vertical direction of the water channel. For example, since water always flows at the bottom of the water channel, the adsorption / capturing performance of the artificial zeolite block 2 on the bottom side (lower) of the water channel is most likely to be reduced the fastest. According to the removal device 1 according to the second embodiment, the artificial zeolite block 2 positioned above the artificial zeolite block 2 to be replaced can be easily lifted. As a result, the artificial zeolite block 2 located below the suspended artificial zeolite block 2 can be easily replaced.

<Third embodiment>
<< Configuration >>
FIG. 7 shows a top view of the contaminant removal apparatus according to the third embodiment. FIG. 8 shows a side view of a contaminant removal apparatus according to the third embodiment. As shown in FIGS. 7 and 8, the removal apparatus 1B according to the third embodiment includes a plurality of artificial zeolite blocks 2, a plurality of stages in the vertical direction, a holding member 5a for holding the artificial zeolite block 2, and a holding member 5a. A support member 9 that supports the artificial zeolite block 2, and a frame body 7 a that supports the suspension tool 6 a. In 3rd embodiment, the case where the removal apparatus 1B is installed in the drainage side groove | channel 3 is demonstrated to an example.

  The plurality of artificial zeolite blocks 2 are composed of three types of artificial zeolite blocks 2 having different aggregate dimensions as in the first embodiment. Moreover, the some artificial zeolite block 2 is arrange | positioned similarly to 2nd embodiment.

The holding member 5a is composed of two rod-like members arranged in parallel, and is provided in three stages in the vertical direction, and holds the artificial zeolite block 2 at each stage. Also in the third embodiment, the holding member 5a is installed in parallel with the direction in which water flows, but the direction of the holding member 5a is not particularly limited. The length of the holding member 5a is designed so that both ends extend from the artificial zeolite block 2 installed without a gap. One end of the holding member 5a is connected to the holding member 5a via a hinge 94, and the other end is connected to a wire 11 that can be lifted by a lifting tool 6a. The holding member 5a has the longest lower holding member 5a and then the middle holding member 5a so that the lower holding member 5a is not buffered with the upper holding member 5a. The holding member 5a is long and the upper holding member 5a is the shortest.

  The support member 9 is installed at the bottom of the drainage side groove 3 and extends in the width direction of the drainage side groove 3, two column portions 92 raised from both longitudinal ends of the base 91, and two column portions Artificial zeolite supported by the holding member 5a while maintaining the horizontal state of the holding member 5a, connected to the brace 93 supporting the 92, the rod-like hinge 94 passed to the two column parts 92, and the two column parts 92 A horizontal maintaining member 95 that supports the block 2 is provided. The holding member 5a and the support member 9 correspond to the fixed unit of the present invention.

  The lifting tool a6 lifts the artificial zeolite block 2 by lifting the wire 11. By changing the holding member 5a to which the wire 11 is connected, the number of artificial zeolite blocks 2 to be lifted can be changed. For example, when the wire 11 is connected to the middle holding member 5, the middle and upper artificial zeolite blocks 2 are lifted. The hanging tool 6a is exemplified by a jack. In the third embodiment, two jacks and a handing member 12 for transferring the two jacks are used. In the third embodiment, two jacks are installed at the top end of the drainage side groove 3, and a transfer member 12 is installed on the top of the jack so as to pass these two jacks. A wire 11 is connected to the transfer member 12, and the tip of the wire 11 can be connected to the holding member 5.

<< How to replace an artificial zeolite block >>
FIG. 9 shows how the artificial zeolite block is replaced in the contaminant removal apparatus according to the third embodiment. First, the jack, the transfer member 12, and the wire 11 as the lifting tool 6a are installed above the artificial zeolite block 2 to be replaced. Next, the wire 11 is connected to the holding member 5. In FIG. 9A, the wire 11 is connected to the middle holding member 5a. Next, the jack as the lifting tool 6a is jacked up, and the transfer member 12 moves upward. One end of each of the middle and upper holding members 5a is connected to a hinge 94, and the holding member 5a rotates upward about the hinge 94 as an axis. As a result, the other ends of the middle and upper holding members 5a are lifted upward. In FIG. 9 (b), the middle and upper artificial zeolite blocks 2 are suspended. When the middle and upper artificial zeolite blocks 2 are lifted, the lower artificial zeolite blocks 2 are replaced. After the replacement, the jack as the lifting tool 6a is jacked down, and the middle and upper artificial zeolite blocks 2 are lowered. The jack, the transfer member 12, and the wire 11 as the lifting tool 6a are removed, and the replacement of the artificial zeolite block 2 is completed.

<< Action and effect >>
The removal apparatus 1B according to the third embodiment has the following effects in addition to the effects of the removal apparatus 1 according to the first embodiment. In the water channel (for example, the drainage side groove 3 as in the third embodiment), the adsorption / capturing performance of the artificial zeolite block 2 arranged varies depending on the position in the vertical direction of the water channel. For example, since water always flows at the bottom of the water channel, the adsorption / capturing performance of the artificial zeolite block 2 on the bottom side (lower) of the water channel is most likely to be reduced the fastest. According to the removal apparatus 1B according to the third embodiment, the artificial zeolite block 2 positioned above the artificial zeolite block 2 to be replaced can be easily lifted. As a result, the artificial zeolite block 2 located below the suspended artificial zeolite block 2 can be easily replaced.

  The preferred embodiments of the present invention have been described above, but the contaminant removal apparatus according to the present invention is not limited to these, and can include combinations thereof as much as possible.

DESCRIPTION OF SYMBOLS 1 ... Pollutant removal apparatus 2 ... Artificial zeolite block 21 ... 1st artificial zeolite block 22 ... 2nd artificial zeolite block 23 ... 3rd artificial zeolite block 3 ... Drainage side groove 4 ... Catchment basin 5, 5 a ... Holding member 6, 6 a ... Suspension tool 7, 7 a ... Frame body 71 ... Base part 72 ... Column part 73 ... Beam Part 8 ... Chain 9 ... Support member 10 ... Jack 91 ... Pedestal 92 ... Pillar part 93 ... Brace 94 ... Hinge 95 ... Horizontal maintenance member 11 ... Wire 12 ... Delivery member

Claims (6)

A pollutant removal device,
A porous concrete block including an aggregate whose surface is coated with zeolite, wherein at least one of the dimension of the aggregate and the porosity, which is a ratio of voids formed between the aggregates, are different A plurality of porous concrete blocks;
A block fixing unit that supports the plurality of porous concrete blocks in a channel through which water contaminated with the contaminant flows;
Contaminant removal device comprising:   2. The pollutant of claim 1, wherein the plurality of porous concrete blocks have an aggregate size of an upstream porous concrete block larger than an aggregate size of a downstream porous concrete block in the water flow. Removal device.   The porous porous concrete block according to claim 1 or 2, wherein the porosity of the porous concrete block on the upstream side is larger than the porosity of the porous concrete block on the downstream side in the water flow. Removal device.   The plurality of porous concrete blocks, at least one of the aggregate size and the porosity of the porous concrete block changes stepwise from the upstream side to the downstream side in the water flow. 4. The contaminant removal apparatus according to any one of 1 to 3. The block fixing unit is
The contaminant removal apparatus according to any one of claims 1 to 4, further comprising a plurality of holding portions that hold the porous concrete block and are provided in a plurality of stages in the vertical direction. The block fixing unit is
Holding the porous concrete block, a plurality of holding portions provided in a plurality of stages in the vertical direction,
A hinge part to which one ends of the plurality of holding parts are connected;
The contaminant removal apparatus according to any one of claims 1 to 5, further comprising: a support portion provided with the hinge portion and rotatably supporting the plurality of holding portions with the hinge portion as an axis. .

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