JP4619909B2 - Shooting range lead purification system - Google Patents

Description

  The present invention relates to a lead purification system for a shooting range for preventing lead leakage from a shooting range contaminated with lead by bullets.

  Traditional shooting ranges have been established using natural hills. In these shooting ranges, bulletproof slopes are provided to prevent the bullets from splashing outside the firing range, and the bullets accumulated on the bulletproof slopes are left without being collected in most cases. For this reason, there are concerns about groundwater contamination due to lead, which is a component of bullets, and lead contamination of the soil in the surrounding area, and techniques for preventing lead contamination from the shooting range have been proposed.

For example, Patent Documents 1 to 3 propose a technique in which soil in which bullets are accumulated in a shooting range is collected, and lead is separated and collected using sieving, specific gravity difference, or the like.
JP 2004-148250 A JP 2003-305411 A JP 2004-98013 A

Further, Patent Document 4 describes a recovery method in which after cutting a plant in an area where bullets are accumulated, high pressure air is sprayed to expose the bullets, and the bullets are sucked and collected by a vacuum device.
JP 2002-372400 A

Furthermore, Patent Document 5 describes a technique for preventing lead elution by spraying phosphate on soil in which bullets are accumulated to insolubilize lead.
JP 2000-189943 A

Patent Document 6 describes a method of adsorbing and removing lead eluted from bullets with vermiculite laid in the ground.
Japanese Patent Laid-Open No. 2003-300054

  However, in the method for collecting and removing the bullets by collecting the soil described in Patent Documents 1 to 3, since the soil in which the bullets are accumulated must be collected, a large heavy machine or a device for separating and collecting is required. This is necessary and increases the cost for separate collection. In addition, since the soil on the bulletproof slope to prevent bullets from being exposed is exposed, not only the natural landscape is damaged, but the bulletproof slope is liable to collapse, and the bullets accumulated there will flow out downstream. There is also a fear.

  In this regard, the method for sucking and collecting bullets with the vacuum device described in Patent Document 4 can reduce the cost for separate collection. However, since the vegetation in the area where the bullets are accumulated is cut down, not only the natural landscape is impaired, but also the effect of preventing soil collapse by the vegetation is impaired. For this reason, there is a possibility that bullets accumulated on the slope flow out downstream.

  Moreover, in the method described in the above-mentioned Patent Document 5 for preventing elution of lead by spraying phosphate to insolubilize lead, the sprayed phosphate is eluted and flows downstream to contaminate rivers and groundwater. There is a risk.

  Furthermore, in the method of adsorbing and removing lead eluted from bullets with the use of vermiculite described in Patent Document 5, vermiculite must be laid in the ground, resulting in high processing costs. In addition, since the lead metal is accumulated at a high concentration in the shooting range soil, the load of lead on vermiculite is high, and there is a possibility that the adsorption capacity of lead may be reduced in a short period of time.

  The present invention has been made in view of the above-described conventional circumstances, has a low processing cost, does not impair the natural landscape, and can stably prevent the outflow of lead over a long period of time. Providing a lead purification system is a problem to be solved.

  The inventors considered using a lead adsorbent such as zeolite or ion exchange resin to treat the wastewater from the shooting range. However, since a large amount of bullets containing lead as a main component is accumulated in the shooting range, the load of lead due to the drainage discharged therefrom is considerably high. For this reason, when it is going to process with a lead adsorption substance alone, the load of lead will become high with respect to a lead adsorbent, and a lead adsorbent must be replaced | exchanged frequently or should be reprocessed. As a result of further diligent research to solve these problems, we established a plant breeding section that grew buckwheat, buckwheat and other plants on a flat surface extending from the bottom of the bulletproof slope and the bottom of the bulletproof slope. It has been found that the above problems can be solved by reducing the load of lead, and the present invention has been made.

  In other words, the lead purification system for a shooting range according to the present invention is a lead purification system for a shooting range including a bulletproof slope for preventing the bullets from scattering outside the firing range, and extends from the bulletproof slope and the bottom of the bulletproof slope. And a lead-adsorbing part for removing treated water by removing lead in waste water discharged from the plant-growing part by using a lead adsorbent. It is characterized by having.

  The lead purification system for a shooting range according to the present invention is provided with a plant growing section in which plants are grown on at least one of a bulletproof slope and a flat land extending from the bottom of the bulletproof slope. For this reason, it is possible to prevent the SS component (suspended substance) in the rainwater from being filtered by the roots of the plant, and the SS component from flowing into the lead adsorbent of the lead removal device to reduce the lead removal ability. Moreover, since the plant has the property of absorbing and accumulating lead in the soil, the load of lead on the lead removing device can be reduced. For this reason, it is not necessary to change the lead adsorbent of the lead removing apparatus so frequently, and the processing cost is also low. Furthermore, if a plant breeding section is provided on the bulletproof slope, the plant roots have the effect of preventing the fall of the bulletproof slope, and also serve as a filter to hold the bullet and prevent the bullet from flowing downward. Can do.

  Therefore, according to the lead purification system of the present invention, the processing cost is low, the natural landscape is not impaired, and lead can be stably prevented from flowing out over a long period of time.

  In the plant growing part, it is preferable that a buckwheat plant and / or a buckwheat genus plant is grown.

  The term “fever plant” is a concept that includes other plants such as centipede grass, centipede grass, and other pastures and covered plants. Since these fern plants are rooted vertically and horizontally in the ground, bullets can be prevented from entering the lead adsorbing portion with the outflow of soil. It is particularly effective to grow a fern plant on a bulletproof slope because it can prevent the bulletproof slope from collapsing. In addition, shiba plants are not so tall and supple, so that they do not get in the way when bullets appearing on the soil surface are collected by a vacuum device. Furthermore, the above-ground part of the fern plant acts as a sieve to prevent bullets from rolling down. Examples of the plant belonging to the genus Shiba include Japanese turf such as wild turf, ginseng turf, hime korai turf and velvet turf, and western turf such as perennial ryegrass and tall fescue. Moreover, since centipede glass is excellent in drying resistance, cold resistance, and snow resistance, it can be suitably used.

  Moreover, according to the test results of the inventors, buckwheat plants are excellent in the effect of accumulating lead, and the effect of reducing the load of lead applied to the lead removing device is high. Although it does not specifically limit as a kind of buckwheat genus plant, Common buckwheat (Fagopyrum esculentum), Shakuchirisoba (Fagopyrum cymosum), Tartary buckwheat (Fagopyrum tataricum) etc. are mentioned.

  The buckwheat plants and buckwheat plants may be grown anywhere on the bulletproof slope and the flat land extending from the bottom of the bulletproof slope, but the buckwheat plant is grown on the bulletproof slope to prevent soil runoff from the bulletproof slope. It is effective to grow buckwheat plants on the extended flat land to absorb the eluted lead in the soil.

  Examples of the lead adsorbent for the lead removing device include zeolite, ion exchange resin, vermiculite and the like. The inventors have confirmed that lead can be reliably removed by using zeolite as a lead adsorbent.

  It is preferable that the contact between the waste water and the lead adsorbent can be performed without using power by natural flow. In this way, the running cost for operating the lead removal adsorption device can be reduced.

  Hereinafter, embodiments embodying the present invention will be described in detail.

  The lead purification system of the shooting range of the embodiment is installed at the shooting site ruins provided in the hilly area outside the city. As shown in FIG. 1, the shooting range includes a bulletproof slope 1 whose slope is artificially cut to be a slope and a flat ground 2 extending from the slope of the bulletproof slope 1. Facilities such as the position X where the shooter stands and the target Y exist on the flat ground 2, and the shooter fires bullets toward the bulletproof slope 1. For this reason, a large amount of lead bullets are accumulated on the bulletproof slope 1.

  A centipede glass 3 is planted on the entire surface of the bulletproof slope 1, and a drainage groove 4 for collecting rainwater from the bulletproof slope 1 is provided at the bottom of the bulletproof slope 1. A concrete tank 5 is installed next to the drainage groove 4, and rainwater from the drainage groove 4 flows into the concrete tank 5 through the inflow port 5 a.

  As shown in FIG. 2, the concrete tank 5 includes a buckwheat breeding tank 6, a sand settling tank 7, and a lead adsorption tank 8. Buckwheat breeding tank 6 is filled with soil and is normally planted with buckwheat (Fagopyrum esculentum). The overflowing water from the buckwheat breeding tank 6 flows into the sand settling tank 7, and further, the overflowed water from the settling tank 7 flows into the lead adsorption tank 8. The lead adsorption tank 8 is divided into three tanks, a first tank 8a, a second tank 8b, and a third tank 8c, by partitions 9a and 9b, and each tank has a partition 10a whose lower end does not reach the bottom surface 5a of the concrete tank 5. 10b and 10c are provided. Further, concrete porous plates 11a, 11b, and 11c that extend from the lower ends of the partitions 10a, 10b, and 10c to the walls of the partitions 9a and 9b and the concrete tank 5 are provided to extend horizontally. The upper end of the 3rd tank 8c is connected to the drainage groove 12 via the outflow port 5b. The first tank 8a, the second tank 8b, and the third tank 8c are filled with the artificial zeolite 13 on the perforated plates 11a, 11b, and 11c. This zeolite uses coal ash generated from a coal-fired thermal power plant as a raw material, and has a cation exchange function (CE) of 200 or more.

  FIG. 3 shows the change over time in the lead removal rate when the lead purification system configured as described above is operated for 320 days. The removal rate was measured by measuring the concentration of lead in the water entering from the inlet 5a and the concentration of lead in the wastewater discharged from the outlet 5b, and obtaining the lead removal rate from these values. . As can be seen from FIG. 3, the lead removal rate was almost 100% over the entire period, and it was found that an excellent lead removal rate could be maintained over a long period of time. The reason why the removal rate dropped to 80% or less around the 170th day is that there was a lot of rain and a part of the waste water overflowed without contacting the zeolite.

  In this lead purification system, since the roots of the centipede glass 3 are stretched vertically and horizontally on the bulletproof slope 1 in which bullets are accumulated, the bulletproof slope 1 can be prevented from collapsing. Further, the bullets are prevented from being caught by the centipede glass 3 and flowing out downward. For this reason, it is possible to prevent lead bullets from flowing into the drainage grooves 4 and entering the lead adsorption tank 8. Furthermore, since the centipede glass 3 is not so tall and supple, the fine lead shot accumulated on the surface of the bulletproof slope 1 can be easily recovered using a vacuum device.

  Further, the rainwater containing lead flowing out from the bulletproof slope 3 flows into the buckwheat breeding tank 6 through the drainage groove 4 and the inlet 5a. In the buckwheat breeding tank 6, lead components in rainwater are normally absorbed by buckwheat, so the lead concentration in the water overflowing from the buckwheat breeding tank 6 decreases. For this reason, the overload of lead to the lead adsorption tank 8 can be prevented. Moreover, since the earth and sand containing the bullets which flowed from the drainage groove 4 accumulates in the buckwheat breeding tank 6, the inflow of earth and sand to the lead adsorption tank 8 can be prevented.

  The water overflowing from the buckwheat breeding tank 6 enters the adjacent sand settling tank 7 where fine earth and sand are settled. Then, the supernatant liquid of the sand settling tank 7 overflows and enters the first tank 8a, flows in from the porous plate 11a, and contacts the zeolite 13. Here, lead is adsorbed on the zeolite by the ion exchange ability of the zeolite. And the water which overflowed from the partition 9a through the 1st tank 8a enters into the 2nd tank 8b, flows in from the perforated plate 11b, and contacts the zeolite 13. FIG. Further, the water overflowing from the partition 9b through the second tank 8b enters the third tank 8c, flows in from the perforated plate 11c, and contacts the zeolite 13. In this way, the waste water from which lead has been removed in contact with the zeolite in the three tanks flows out to the drain groove 12 through the outlet 5b.

  As described above, since this lead purification system is provided with the centipede glass 3 and the buckwheat breeding unit 6 planted on the bulletproof slope 1, lead overload and sediment inflow into the lead adsorption tank 8 are prevented. It can prevent lead outflow stably over a long period of time. Further, in the treatment of lead, since the flow of water is used and no power is used, the running cost is extremely low. Moreover, since the centipede glass 3 and the normal buckwheat are cultivated on the bulletproof slope 1 and the flat ground 2, the natural landscape is not impaired.

  In order to verify the effects of the buckwheat breeding unit 6 and the centipede glass 3 in the lead purification system, the following tests were performed.

(Lead accumulation test with buckwheat)
Various plants were cultivated with soil contaminated with lead, and the amount of lead contained in the grown adult was measured. The growth bed 20 shown in FIG. 4 was used for plant growth. The growth floor 20 is squarely surrounded by water-resistant veneers 21, a waterproof sheet 22 is laid on the bottom, crushed stones 23 are laid on it, and soil is further filled thereon. The soil was dried and lead nitrate was added at a rate of 9000 mg / kg. The seeds of various plants were planted on this growth bed 20 and harvested two months after sowing, and the dry weight of leaves and stems and the lead concentration were measured. Plants sowed are common buckwheat, Sudangrass, Guineagrass, corn, kenaf, white mustard, rye, fascia, Italiangrass and orchidgrass.

  FIG. 5 shows the amount of lead accumulated when grown as described above. From this figure, it can be seen that ordinary buckwheat has a much higher effect of accumulating lead than other plants.

Moreover, drainage was extracted from the layer where the crushed stones 23 of the growth floor 20 were spread, and the drainage amount and lead concentration were measured for a drainage tank (not shown). The measurement was performed when normal buckwheat was grown and when nothing grew, and the growing period was 80 days. The results are shown in Table 1.

  As shown in Table 1, it was found that when normal buckwheat was grown, the lead concentration in the waste water was lower than when no plant was grown, and lead elution could be reduced by 77.3%.

(Soil and bullet discharge test with shiba)
Instead of planting the centipede glass 3 on a part of the bulletproof slope 1, in order to investigate the effect of the centipede glass 3 on preventing soil and bullets from flowing out, a portion with a 2 mm mesh is provided, and the lead content, lead elution amount, The number of lead bullets, the amount of soil, the lead concentration of centiped glass and the amount of lead taken by centiped glass were measured. The lead content was measured by the Ministry of the Environment Notification No. 19 test method (2003), and the lead elution was measured by the Environment Agency Notification No. 46 test method (1991). The number of lead bullets was measured by screening the soil and collecting the lead bullets and counting the number. Furthermore, the amount of soil is a measure of the weight of the soil that entered. The results are shown in Table 2.

  From Table 2, by planting the centipede glass 3, it was possible to prevent runoff of lead bullets and soil with an effect more than applying a 2 mm mesh net. Moreover, it has been found that centipede glass itself has a property of accumulating lead, and a part of lead can be recovered by cutting this.

  In the above embodiment, buckwheat is grown in the concrete buckwheat breeding tank 6, but it is of course possible to grow buckwheat in simple soil without providing a tank.

  The present invention can prevent lead from flowing out of a lead-contaminated shooting range.

It is a schematic cross section of the lead purification system of the shooting range of the embodiment. It is a schematic cross section of the principal part of the lead purification system of the shooting range of the embodiment. It is a figure which shows the time-dependent change of the lead removal rate in the lead purification system of the shooting range of embodiment. It is a schematic cross section of the breeding floor which performed the lead accumulation test. It is a graph showing the lead content and lead sequestration amount of various plants.

Explanation of symbols

1 ... Bulletproof slope 2 ... Flat ground 3, 6 ... Plant breeding department (3 ... Centipede grass, 6 ... Buckwheat breeding tank)
13 ... Lead adsorbent (zeolite)
8 ... Lead adsorption part (8a ... 1st tank, 8a ... 2nd tank, 8a ... 3rd tank)

Claims (3)

A lead purification system for a shooting range with a bulletproof slope to prevent bullets from splashing outside the shooting range,
A drainage ditch for collecting rainwater from a bulletproof slope, a plant growth tank into which rainwater collected in the drainage ditch flows, and a lead adsorption tank filled with a lead adsorbent into which wastewater overflowed from the plant growth tank flows And
A lead purification system for shooting ranges characterized in that buckwheat plants are grown in the plant growing tank .   2. The lead purification system for a shooting range according to claim 1, wherein the contact between the waste water and the lead adsorbent can be performed without using power by natural flow.   The lead purification system for a shooting range according to claim 1 or 2, wherein the lead adsorbent is zeolite.

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