JP3389113B2 - Artificial ground soil - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a planting soil for artificial ground. More specifically, the present invention relates to a soil for artificial ground such as a rooftop using soil generated from a water purification plant, which is excellent in physical properties.

[0002]

2. Description of the Related Art The use of soil from a water purification plant as a medium for growing plants is described in detail in "Water Treatment Cake: Characteristics and Problems in Agricultural Utilization" edited by Japan Society of Soil Fertilizers (Hakuyusha). There is. In general, the following problems are raised in order to use the soil generated from the water purification plant as a plant growth medium. Soil generated from the water treatment plant that has been dehydrated under pressure has a plate-like shape, and the size of the soil also varies widely, and the physical properties of the soil material for artificial ground cannot be ensured as it is. The water content of the soil produced by the water treatment plant varies seasonally, with low summer and high winter. Polyaluminum chloride and aluminum sulphate are added during the process of water purification, and the aluminum content in the generated soil becomes extremely high, resulting in phosphate-deficient soil. Naturally-occurring manganese contained in suspended matter in raw water
It is a manganese-rich soil with an increased manganese content in the soil generated from the water purification plant.

When the soil produced by the water purification plant is used as a medium for growing plants such as vegetables, flowers and trees, the purpose is to solve the above-mentioned problems of the soil produced by the water purification plant such as phosphoric acid fixation by aluminum and excess manganese. Furthermore, it is necessary to optimize the physical properties such as water permeability and water retention of the medium and the chemical properties such as pH and EC for the growth of plants. To obtain a plant growth medium by using water purification plant generated soil that has been dehydrated by a pressure method by adding polyaluminum chloride or aluminum sulfate as a coagulant, a zeolite is mixed in the treatment water generated soil in an amount of 32 to 70%. Method (Japanese Patent Laid-Open No. 4-197110),
A bark (bark) that was crushed into fine particles to finely crush the purified water cake to adjust the water content and improve the soil suitable for plant culture soil.
By mixing with organic materials, such as organic materials, and by adding animal and plant organic fertilizers, the activity of effective microorganisms such as bacteria and actinomycetes is promoted, and it is widely used for agriculture, tree planting, spraying for slope greening, etc. A method for producing a high-nutrient culture soil for use (Japanese Patent Laid-Open No. 05-207816), a method for adding cow dung compost and rice husks to a water treatment plant soil, and incubating at 25 to 30 ° C. for a certain period before use ( Journal of Japan Soil Fertilizer Society No. 6
Volume 4, No. 4 (1993) P. 385-392). These methods are optimal for industrially producing a large amount of plant growth medium because of the time-consuming production, poor production efficiency, and insufficient physical / chemical properties optimal for plant growth. Instead of the method, for this purpose, a method of mixing compost, peat moss, phosphate fertilizer, etc. with the soil produced from the water treatment plant (Japanese Patent Laid-Open No. 5-219832) or a water purification plant containing excess manganese in the soil produced from the water treatment plant A method of further mixing zeolite, lightweight cellular concrete, coral or the like with the field-generated soil (JP-A-7-227144) is preferable. However, most of these methods assume cultivation such as cultivation using pots or planters as cultivation medium and planting soil as a medium for growing plants, and they are also suitable for special usage such as artificial ground such as rooftops. Not really. Especially when planting trees, the cultivation period becomes long, and in some cases semi-permanent, the amount of soil decreases over time, and soil porosity is filled by erosion, resulting in poor air permeability and water permeability. It was a matter of maintaining physicality. Also, when using purified water cake or bark compost, the water spilled from the soil may be colored, and if drainage is not done properly, the structure such as the rooftop surface may be colored and spoil the appearance. was there.

On the other hand, in the case of greening on the rooftop, a method of applying a waterproof treatment to the rooftop surface and then providing a drainage layer with obsidian-based perlite or a special drainage board and then planting soil as a soil for planting is adopted. The soil used is natural soil, natural soil improved with a soil improving material, or artificially manufactured lightweight soil. When natural soil is used, a soil environment suitable for plant growth can be obtained, but there are problems that the weight becomes heavy and it is difficult to obtain high-quality natural soil. Artificial lightweight soils are inorganic artificial lightweight soils containing pearlite obsidian perlite as the main component, organic mixed artificial lightweight soils containing obsidian perlite and burned rocks with organic materials, and organic substances mainly containing coniferous bark. Classified as artificial lightweight soil. Since these soils are made as soils with the minimum performance that plants can survive for the purpose of weight reduction and improvement of water retention, the properties are greatly different from natural soils, poor fertilizing ability and buffering ability, Not necessarily favorable conditions for plant growth such as easy degradability of organic matter and soil microorganisms, poor growth of planted trees, yellowing of leaves,
In some cases, phenomena such as plant decline over a long period of several years were observed. Therefore, in order to obtain good quality green,
Fertilizer management and brackish water management needed to be performed more finely than when using natural soil.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reduce the deterioration of physical properties and the coloring of buildings due to runoff when the purified water cake is used as soil for artificial ground such as a rooftop. The purpose of the present invention is to provide a soil for artificial ground such as a rooftop that uses soil generated from a water purification plant, which has high fertilizer retention and buffering ability, contains sufficient easily degradable organic matter and soil microorganisms and is suitable for plant growth.

[0006]

The present invention relates to a soil for artificial ground which is obtained by adding porous volcanic gravel to the soil generated from a water purification plant. Further, the present invention relates to soil for artificial ground obtained by adding porous volcanic gravel and charcoal to the soil generated from the water purification plant. Furthermore, the present invention provides porous volcanic gravel in the soil of the water purification plant 10 times.
The present invention relates to a soil for artificial ground, which is obtained by adding an amount of ˜30% by volume and charcoal of 3 to 15% by volume. Furthermore, the present invention adds porous volcanic gravel in an amount of 10 to 30% by volume, charcoal of 3 to 15% by volume, and bark compost, peat moss, perlite, and phosphate fertilizer to the water treatment plant soil. The present invention relates to the soil for artificial ground obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The water treatment plant-generated soil targeted by the present invention is a non-chemical-injection soil generated in the dehydration process of the water purification plant. The amount of the soil generated from the water purification plant is usually 30 to 80% by volume, preferably 40 to 60% by volume in the artificial soil of the present invention. In the present invention, it is preferable to crush the soil produced by the water purification plant. Since the soil from the water purification plant is viscous and tends to adhere to the crushing equipment, it is desirable to use a special crushing equipment when crushing. It is desirable that the soil generated from the water purification plant after crushing has a particle size of 16 mm or less, preferably 12 mm or less. Here, the particle size distribution is determined by measuring the weight of the particles that have passed through a mesh sieve specified in JIS Z 8801-1994.

In the present invention, porous lapilli are added to the soil produced by the water purification plant. Porous pebbles are usually porous scoria, which is black or brown in the size of adzuki bean, and when the magma is released into the atmosphere or water, the internal gas is released due to a sudden decrease in the external pressure, and it becomes porous. It includes pumice, which is a piece of rock. Among these, it is desirable that the hardness of the grains is not less than that which can be easily broken with fingers, and that the specific gravity when wet is 0.8 or more and 1.2 or less. Particle size is 5 to 3
The range of 0 mm is desirable, and further 10 to 20 mm
Those in the range of are desirable. The addition amount of the porous lapilli is usually 10 to 30% by volume, preferably 15 to 25% by volume in the soil of the present invention.

In the present invention, it is preferable to add charcoal to the soil generated from the water purification plant. The charcoal added in the present invention may be any charcoal obtained by carbonizing plant organic matter, and depending on the material, charcoal, rice husk charcoal, papermaking sludge charcoal, waste paper sludge charcoal, food sludge charcoal, coffee slag charcoal, beer slag. There are charcoal and livestock manure. The particle size of the charcoal used in the present invention is usually 3 to 2
A diameter of 0 mm, preferably 5 to 10 mm is desirable. The amount of addition to the soil generated from the water purification plant is usually 3 to 15% by volume, preferably 5 to 10% by volume in the soil for artificial ground of the present invention.

In the present invention, it is preferable to further add bark compost, peat moss, perlite and phosphate fertilizer to the soil generated from the water purification plant. The bark compost to be added in the present invention is a compost obtained by a conventional method by adding chicken dung, urea or the like to the bark of a tree, naturally depositing it or artificially mechanically treating it. The amount added to the soil generated from the water purification plant is usually 10 to 40% by volume in the soil material for artificial ground of the present invention, preferably 2
The amount is 0 to 30% by volume. The peat moss added in the present invention is obtained by carefully selecting, drying, and crushing Mizugoke peat (grass charcoal), and is designated as a soil improving material by soil softening and water retention improvement, and is commercially available. The peat moss to be added to the present invention is not particularly limited, but those having a water content of 35% or more and 45% or less are desirable. The amount added to the soil produced by the water purification plant is usually 5 to 30% by volume, preferably 10 to 20% by volume in the soil material for artificial ground of the present invention. The phosphate fertilizer added in the present invention is
As described in Japanese Patent Application Laid-Open No. 10-88137, a phosphate fertilizer applied for general agriculture is used, and 20% by weight of fusible phosphoric acid is used as a guaranteed phosphoric acid component in the total phosphoric acid contained therein.
Contains 50% or more of water-soluble phosphoric acid
Used alone or in combination of two or more so as to be less than or equal to%. The addition amount of the phosphate fertilizer is usually 500 mg / content in the soil for artificial ground of the present invention as the phosphate component.
Amount of liter or more is preferable, especially 800 to 20
An amount of 00 mg / liter is preferable. In the present invention, it is preferable to add perlite when it is desired to lower the specific gravity when wet. Perlite is obtained by crushing rock, heating it at high temperature, and foaming it. Depending on the rock material, there are pearlite and obsidian. In the present invention, it is particularly preferable to use obsidian pearlite. The particle size of the obsidian pearlite used in the present invention is usually 2 to 20 mm, preferably 5 to 10 mm. The amount added to the soil generated from the water purification plant is usually 5 to 30% by volume, preferably 10 to 20% by volume in the artificial ground soil of the present invention.

[0011]

[Effects of the Invention] By adding porous gravel to the water purification cake, it is possible to reduce the deterioration of physical properties that occurs when the water purification cake is used as artificial soil, and by adding charcoal to the water purification cake, Reduces the coloring of buildings due to runoff that occurs when using a water purification cake for artificial ground soil,
The soil for artificial ground such as a rooftop, which has a high fertilizing power and a high buffering power, contains a sufficient amount of easily decomposable organic matter and soil microorganisms and is suitable for growing plants, can be obtained. Therefore, according to the present invention, the purified water cake can be effectively used as a green soil for artificial ground such as a rooftop.

[0012]

EXAMPLES The present invention will be described in more detail based on the test examples and examples, but the present invention is not limited to these test examples and examples.

Test Example 1 60% by volume of soil generated from a water purification plant, 20% by volume of bark compost, 15% by volume of peat moss, and 5% by volume of charcoal were mixed with porous volcanic gravel at the ratio shown in Table 1. Then, the physical properties were measured. Pumice stone from Kanazawa was used as the tested porous lapilli, and the particle size was adjusted to 3 to 20 mm. Assuming a change in physical properties during and after construction, the survey was conducted using the following method. Soil is filled into a cylindrical test container having a volume reduction rate of 5 liters (depth 19.8 cm) during construction. At this time, the test container is dropped from a height of 5 cm three times to fill the soil, and the soil is filled into the ground. An average static pressure of 0.3 kg / cm ² is applied to the soil surface in the test container, the sedimentation length of the soil from the test container surface is measured, and the volume reduction rate is calculated. The three-phase distribution at pF1.8 was measured by the actual volumetric method. The saturated hydraulic conductivity was also measured. These measurements were carried out by the methods described in Soil Environment Analysis Method, Soil Environment Analysis Method Editing Committee, Hakuyusha. The results are shown in Table 1.

Change in physical properties after construction Excess water is drained, but soil is filled into a cylindrical test container having a capacity of 5 liters (depth 19.8 cm) with a net installed so as not to run out. At this time, the test container is 5c
It is dropped three times from the height of m and stuffed with soil, and filled to a level of scraping. Leave it outdoors for 3 months, measure the sedimentation length of the soil from the surface of the test container, and further 10 cm from the soil surface.
Soil is sampled with a 50 ml sample cylinder from the point
The three-phase distribution and saturated hydraulic conductivity at F1.8 were measured. Sampling of samples, three-phase distribution, and measurement of saturated hydraulic conductivity were carried out by the methods described in Soil Environment Analysis Method, Soil Environment Analysis Method Editing Committee, Hakuyusha. The results are shown in Table 2.

[0015]

[Table 1] Table 1 Effect of addition of porous lapilli on physical properties of soil assuming construction ────────────────────────── ─────────── No. Addition amount Volume reduction rate Three-phase distribution (%) Saturated hydraulic conductivity (% by volume) (%) Solid phase Liquid phase Gas phase (m / S) ────────────────── ───────────────── 1 0 22.1 23 46 46 31 2.3 × 10 ^-4 2 10 17.8 26 43 31 1.9 × 10 ^-3 3 20 14 6.6 34 37 29 1.8 x 10 ^-3 4 30 12.2 36 36 27 27 1.9 x 10 ^-3 5 40 11.8 43 30 27 1.6 x 10 ^-3 ───────── ────────────────────────────

[0016]

[Table 2] Table 2 Effect of addition of porous lapilli on physical properties of soil after construction ────────────────────────── ─────────── No. Addition amount Volume reduction rate Three-phase distribution (%) Saturated hydraulic conductivity (% by volume) (%) Solid phase Liquid phase Gas phase (m / S) ────────────────── ────────────────── 1 0 23.4 32 47 47 9.3 × 10 ^-4 2 10 18.6 32 46 46 22 4.2 × 10 ^-3 3 20 15.1 36 38 26 26 3.2 × 10 ⁻³ 4 30 11.9 38 38 37 25 1.8 × 10 ⁻³ 5 40 11.5 44 29 27 27 1.6 × 10 ⁻³ ──────── ─────────────────────────────

As can be seen from the results shown in Table 1, the volume reduction rate ((actual capacity-design capacity) / design capacity) tends to decrease with the addition of porous lapilli. It was suggested that the dandruff rate (actual capacity / designed capacity) at the time of construction is decreased and the yield is increased and the physical properties are stabilized. Moreover, in the three-phase distribution, the solid fraction tended to increase with the mixing of porous lapilli. Here, the design capacity indicates the area of the soil × the thickness of the soil. As can be seen from the results shown in Table 2, in the result of the physical examination assuming post-construction, the volume reduction rate is similar to that when the construction was performed, and the volume reduction rate was increased by the addition of porous lapilli. The tendency was to decrease. Regarding the three-phase distribution, the solid phase ratio increased significantly when porous gravel was not added, but the increase was smaller due to the mixing of porous gravel than when the construction was assumed. It was also suggested that the saturated hydraulic conductivity increases as the proportion of porous lapilli added increases, and the poor permeability is reduced by the addition of porous lapilli. In addition, these values show that the addition ratio of porous lapilli is 30
There was no big difference above%.

Test Example 2 Table 3, Table 4 and Table 5 show a mixture of 60% by volume of soil generated from a water purification plant, 15% by volume of bark compost, 5% by volume of peat moss, and 20% by volume of pumice from Kanazawa. Charcoal was mixed at a ratio to make a test soil. Fertilizer is 1 phosphorus as fertilizer
500 mg / l was added. The effects of addition of charcoal on the water retention of artificial soil, the growth of plants, the coloring of structures, and the effect of soil on base exchange capacity (CEC), organic matter content and microbial count were investigated. Charcoal has a particle size of 3 to 1
0 mm charcoal was used. Long soil 180 (Chisso Asahi Fertilizer Co., Ltd. High Control 085 180 type (Chisso :: Phosphorus: Kali = 1) is used for comparison with natural soil (normal black soil, Tsukuba City) and artificial lightweight soil (mainly perlite).
0:18:15)) was applied at 5 g / l. The growth was compared using white oak and dogwood as the test plants. Test 3
It was repeated. Fill the test soil in a 10 liter pot,
Seedlings with a height of about 1.5 m were planted. The test was started in February 1997, and the tree height growth and leaf color were investigated in October of the same year.
The test was carried out in a concrete-filled open field where water was quickly drained, and irrigation was carried out about 2-3 times a week. At the end of the test, the degree of coloring of the concrete was visually compared.
In addition, the CEC and organic matter content of the soil at the end of cultivation were measured by the dilution plate method for the number of microorganisms by the method described in Soil Environment Analysis Method, Soil Environment Analysis Method Editing Committee, Hakutosha. The results are shown in Tables 3, 4, and 5.

[0019]

[Table 3] Table 3 Effect of addition of charcoal on water retention of artificial soil material and degree of coloring on concrete surface ───────────────────── ──────────────── Addition amount Easy-effective effective water Refractory effective water (Volume) (g / cm ³ ) (g / cm ³ ) Coloring degree on concrete surface ─ ─────────────────────────────────── 0% 0.33 0.12 Remarkably colored 5% 0.34 0.14 Slightly colored 10% 0.31 0.23 Slightly colored 20% 0.31 0.25 Slightly colored Black soil 0.25 0.26 Slightly colored Artificial lightweight soil 0.29 0.20 Almost No coloring ────────────────────────────────────

[0020]

[Table 4] Table 4 Effects of charcoal addition on water retention and plant growth of trees ────────────────────────────────────     Addition amount White oak Dogwood     (Capacity) Tree height extension (cm) Leaf color Tree height extension (cm) Leaf color ────────────────────────────────────     0% 26.9 63.2 33.2 36.9     5% 27.6 66.3 35.1 34.5     10% 29.3 56.9 35.3 33.2     20% 26.0 48.3 28.6 24.5   Black soil 21.6 53.2 30.3 30.1   Artificial lightweight soil 16.9 38.4 26.9 21.0 ────────────────────────────────────

[0021]

[Table 5] Table 5 Effect of addition of charcoal on soil CEC, organic matter content and microbial count ──────────────────────────── ───────── Addition amount CEC Organic matter content Microbial count (cfu) (volume) (%) Bacteria Actinomycetes Filamentous fungi ──────────────────── ───────────────── 0% 50.6 35.1 3 × 10 ⁶ 2 × 10 ⁴ 3 × 10 ³ 5% 48.2 39.6 1 × 10 ⁷ 1 × 10 ⁵ 4 × 10 ³ 10% 49.3 33.9 6 × 10 ⁶ 1 × 10 ⁵ 9 × 10 ³ 20% 46.3 52.1 1 × 10 ⁷ 2 × 10 ⁵ 6 × 10 ³ Black soil 56.3 18.6 7 × 10 ⁴ 1 × 10 ⁵ 5 × 10 ³ Artificial lightweight soil 18.3 2.6 2 × 10 ³ 1 × 10 ³ 1 × 10 ² ─────────── ──────────────────── ─────

As shown in the results of Table 3, it was observed that the addition of charcoal tended to increase the amount of refractory effective water among the effective water (that is, strengthen the dryness). Also, the addition of 5% or more charcoal significantly reduced the coloring on the concrete surface. No significant difference was observed even if the addition amount was increased. As shown in the results of Table 4, in all tree species, the tree growth amount was up to 10%, and the more the amount of charcoal was added, the more vigorous the growth was. However, at 20%, there was almost no difference or the growth was suppressed. There was a tendency to change. In particular, the leaf color tended to become slightly lighter when 20% or more of charcoal was added. In comparison with other soils, all test plots were equal to or higher than ordinary Kuroboku soil, and were significantly larger than the artificial lightweight soil in terms of tree height extension and leaf color. As can be seen from the results shown in Table 5, even without addition of charcoal, CEC was similar to that of Kuroboku soil, and the organic matter content was high. As a result, the number of microorganisms was relatively high. The values of the artificial lightweight soils were low in all items compared with these soils.

Example 1 i) The following materials were mixed in a volume ratio as described below to prepare a green soil for artificial ground such as a rooftop. Clean water cake (80%) Porous gravels (20%) ii) 1500 mg / liter of phosphorus star as phosphoric acid component

Example 2 i) The following materials were mixed in a volume ratio as described below to prepare a green soil for artificial ground such as a rooftop. Clean water cake (70%) Porous gravels (20%) Charcoal (10%) ii) 1500 mg / liter of phosphorus as phosphoric acid component

Example 3 i) The following materials were mixed in a volume ratio as described below to prepare a green soil for artificial ground such as a rooftop when weight reduction is particularly required. Clean water cake (50%) Porous gravels (15%) Charcoal (5%) Bark compost (10%) Peat moss (10%) Obsidian perlite (10%) ii) 1500 mg / l of phosphorus as phosphoric acid component

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Claims (3)

(57) [Claims] 1. Porous gravels are contained in the soil of the water purification plant in an amount of 10 to 10.
Soil for artificial ground obtained by adding an amount of 30% by volume and charcoal of 3 to 15% by volume. 2. The soil generated from the water purification plant is added with porous gravel having a particle size of 5 to 30 mm and charcoal having a particle size of 3 to 20 mm.
Soil for artificial ground described. 3. Porous gravels are contained in the soil of the water purification plant in an amount of 10 to 10.
Soil for artificial ground, which is an amount of 30% by volume, an amount of charcoal of 3 to 15% by volume, and bark compost, peat moss, perlite, and phosphate fertilizer.