JPH03159983A - Agricultural material and production thereof - Google Patents

Abstract

PURPOSE:To obtain an agricultural material effective in improving soil and promoting the growth of crops by forming a calcium phosphate compound on the surface of scarcely soluble granular material and attaching a physiologically active substance to the surface. CONSTITUTION:Scarcely water-soluble granules (e.g. rock phosphate, bone black and Kanuma-tsuchi) are made to contact with a phosphorus-containing liquid in the presence of calcium and alkali to form crystal of calcium phosphate compound on the surface of the granules. The treated granules are immersed in a liquid containing a physiologically active substance (e.g. hormone, agricultural chemicals or lysozyme) to support the physiologically active substance on the surface.

Description

[Detailed Description of the Invention] [Field of Application in Industry] The present invention is applied to agricultural fields, which are used to improve soil and promote or control the growth of crops by spraying on farmland, forests, etc.
It relates to materials (including those for forestry use) and methods of manufacturing them.

[Conventional technology]

In agriculture and forestry, various pesticides, hormones, enzymes, and the like are being researched and developed to improve soil and promote or control crop growth.

These substances are said to act on soil and crops in minute amounts, but if they are sprayed as is, they will leach out of paddy fields and farmland or be decomposed by microorganisms indigenous to the soil, so they will gradually be removed from the stage of spraying. It is preferable to feed the soil or crops to the soil or crops. For this reason, pesticides and the like are granulated to make them easier to spray or to slowly dissolve them.

In addition, as a technology for removing phosphorus from liquid, a method (catalytic dephosphorization method) has been developed in which phosphorus is removed in the form of calcium phosphate by bringing it into contact with phosphate minerals in the presence of calcium and alkali, and this method does not generate sludge. However, no consideration was given to the recovery and utilization of the removed calcium phosphate.

[Problem to be solved by the invention]

By the way, when conventional granulated agricultural chemicals are sprayed, fine particles are scattered, which is not only dangerous for the sprayer but also has a negative impact on the environment. In addition, pesticides have the disadvantage that they only function as pesticides, and even when sprayed, a large portion of the pesticides is unused and flows into the water system. Furthermore, when hormones and enzymes (proteins) are spread on actual farmland, they are decomposed by microorganisms in the soil, resulting in the problem that their effects are not exerted.

The present invention solves the above-mentioned conventional problems and organically combines the catalytic dephosphorization method developed as a phosphorus removal technology with conventional pesticides, hormones, enzymes, etc., and produces extremely effective agricultural materials. The purpose of this invention is to provide a manufacturing method for the same.

[Means to solve the problem]

The present invention is an agricultural material characterized in that crystals made of a calcium phosphate compound supporting a physiologically active substance are formed on the surface of granules that are poorly soluble in water. production of an agricultural material, which comprises contacting the granules with a phosphorus-containing solution in the presence of calcium and alkali to form crystals made of a calcium phosphate compound on the surface of the granules, and then immersing the granules in a physiologically active substance-containing solution. It's a method.

[For production]

The agricultural material of the present invention is a granular material in which crystals made of a calcium phosphate compound supporting a physiologically active substance are formed on the surface of the granular material that is poorly soluble in water, and when sprayed on farmland etc.
As the calcium phosphate compound on the surface gradually dissolves, the physiologically active substances also gradually dissolve in the process, and are effectively used in soil and crops. In other words, Honharō's agricultural materials can provide fertilizer and physiologically active substances at the same time. In addition, the particle size can be adjusted as appropriate,
There is no risk of scattering when spraying, and it can be easily applied locally.

Next, the production of agricultural materials of the present invention will be described below with reference to drawings showing embodiments.

Figure 1 shows an example of forming calcium phosphate compound crystals on the surface of granules that are sparingly soluble in water. A phosphorus-containing liquid 1 is introduced from the bottom of a reaction tank 2, and in the tank, phosphate rock and other granules that are sparingly soluble in water are formed. The granules 3 are brought into contact with each other while being fluidized. A part of the outflow water 4 from the reaction tank 2 is used as treated water, and the other part is returned to the lower part of the reaction tank 2 through the circulation pipe 6 by the circulation pump 5.

As the phosphorus-containing liquid 1 at this time, tap water with phosphorus added or various phosphorus-containing wastewaters can be used.

In addition, the calcium sources necessary for calcium phosphate diet are:
A calcium salt solution 7 is injected into the circulating water pipe 6, and an alkaline source is supplied by injecting an alkaline solution 9 from the lower part of the reaction tank 2 while detecting pi in the effluent water 4 with a pH meter 8. In this process, as shown in FIG.
Adhering granules 12 are obtained.

The granules 12 to which the calcium phosphate compound 10 is attached are
Not only can the particle size be adjusted appropriately, but because it is porous, the specific surface area is as high as 50 to 200 m2/g, and the surface potential is positive under alkaline conditions and negative under acidic conditions. ing.

Particle size can be adjusted by adjusting the phosphorus depth. This is determined by the calcium concentration or the time the particulate remains in the reaction tank 2.

According to this method, the particle size becomes relatively uniform, and the large particle size (
2 to 5) can be obtained by increasing the phosphorus concentration or calcium concentration to increase the crystallization rate of calcium phosphate, or by increasing the time during which the granules remain in the reaction tank 2.

The granules 3 that are poorly soluble in water are preferably phosphate rock, bone charcoal, etc., which exhibit phosphorus adsorption ability, but sand. Anthracite, activated carbon, zeolite. It is also possible to use Kanuma soil or the like.

Further, if calcium carbonate precipitates during the manufacturing process and causes a problem, it is preferable to remove the carbonic substance in the phosphorus-containing liquid 1. Calcium phosphate supports the physiologically active substances described below, so if carbonic substances are present in the phosphorus-containing liquid 1, which is the raw water, crystallization of calcium carbonate will proceed, and the content of calcium phosphate will decrease, or calcium phosphate The precipitation rate decreases. Therefore, if a large amount of carbonic substances are present in the raw water, it is best to remove them by acidic strinobing or the like.

Next, the granules 1 to which the calcium phosphate compound 10 is attached
2 is taken out from the granule removal pipe 1l and introduced into the soaking tank 13 as shown in FIG. A physiologically active substance water}@liquid 14 is present in the immersion tank 13, and is stirred and mixed by a stirrer 15, so that the surface of the introduced granules 12 carries the physiologically active substance. The pi of the liquid at this time is determined by injecting the PU adjustment liquid 17 while detecting it with the pl+ total 16, and determining the maximum loading capacity of the physiologically active substance and the pt+ that does not lose the activity of the physiologically active substance.
It is desirable to control the value.

Examples of preferred physiologically active substances include hormones, pesticides such as herbicides such as baracote and DCPM, and insecticides such as Marathon, and enzymes (proteins) such as zururizozyme, which has a bacteriolytic action.

〔Example〕

Example 1 A cylindrical reaction tank with an inner diameter of 1001 mφ and an effective depth of 2.5 m and an inverted conical bottom was filled with crushed and sieved phosphate rock (vertical diameter of 0.4 mm, uniformity coefficient of 1.4). ) to 1 0
It was filled to a thickness of 0 0 +n. On the other hand, secondary treated water containing phosphorus, which is obtained by treating organic sewage with coarse solids separated and treated with activated sludge, and water obtained by adding phosphorus to tap water are prepared.
The pH was adjusted to 9.0 by adding 12+ ng/g of caustic soda to each of them, and the water was introduced into the bottom of the reaction tank as raw water. Of the water flowing out from the second part of the reaction tank, the same amount as the raw water was added to the reaction tank. While circulating to the lower part, a calcium chloride solution was injected into the circulating water so that the weight ratio of Ca/PO=to the raw water was in the range of 1.0 to 1.5. The upward flow velocity of the raw water and circulating water at this time was set to L V 3 0 to 40 m/h. In addition, a PL+ meter was immersed in the lower part of the reaction tank, and about 23 μ/e of caustic soda was poured into the lower part of the tank so that the PL+ of the water flowing out from the -L part was 9.5, and the tank was operated for one month. A calcium phosphate compound was deposited on the surface of phosphate rock.

After one month, the granules were taken out from the reaction tank and analyzed for their properties. Table 1 shows the properties of phosphate rock as a comparative example.
Shown below.

As shown in Table 1 below, the granules obtained by the present invention had a higher specific surface area than phosphate rock having almost the same chemical composition. In addition, when the phosphorus concentration of raw water is reduced,
It was confirmed that the specific surface area decreased and that the specific surface area could be adjusted appropriately by adjusting the phosphorus concentration of the raw water.

Furthermore, when a similar test was conducted using sand and zeolite as seed crystals, the specific surface area was the same value, but the covering power of calcium phosphate 1 and the compound on the surface was weak, and the compound easily peeled off.

Example 2 5 g of various granules (seed crystals: phosphate rock) produced based on Example 1 were immersed in Solution 2 in which various physiologically active substances were dissolved, and various physiologically active substances were added while stirring at a stirrer rotation speed of 50 rpm. Supported substances. The pl+ of the liquid at this time was adjusted to a value that maximized the supporting capacity.

The results and comparative examples are as shown in Table 2, and the granules according to the present invention were able to support a higher amount of each physiologically active substance than the phosphate rock of the comparative example.

Margin table below - 2 1 1 Example 3 1 g of the baraquat of Example 2 on which 300 μ/g of particles were supported was immersed in 1 liter of water with a pl of 16.5, and the rate of release of paraquat and phosphorus into the water was determined. was measured. As a control example, 1 g of commercially available paraquat granules (300 ml of paraquat) was immersed in water 14 with a pl of 16.5 and similarly measured. The results are shown in Table-3.

As shown in Table 3, it was found that the granules according to the present invention gradually released paraquat and also gradually released phosphorus. In addition, after the calcium phosphate compound coating the surface is dissolved, the phosphate rock of the seed crystal becomes 0. 0 5m
Phosphorus was released at a rate of g/n − h.

〔Effect of the invention〕

12 As described above, the agricultural material according to the present invention forms a calcium phosphate compound on the surface of granules that are poorly soluble in water, and also supports biologically active substances, and when sprayed on farmland, forests, etc., it releases phosphorus and physiological substances. The active substance is gradually released,
It is effective for improving soil and promoting and controlling the growth of living organisms, and its production is also extremely easy by using the catalytic dephosphorization method.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram of the process of forming calcium phosphate compound crystals on the surface of granules that are refractory to water, and FIG. 2 is a cross section of the granules obtained in FIG. 1. FIG. 3 is an explanatory diagram of the step of further supporting a physiologically active substance. DESCRIPTION OF SYMBOLS 1... Phosphorus-containing liquid, 2... Reaction tank, 3... Particulate matter hardly soluble in water, 4... Effluent water, 5... Circulation pump,
6... Circulating water pipe, 7... Calcium salt solution, 8,1
6...pH meter, 9...alkaline solution, 10...calcium phosphate compound, 1I...particle removal tube, 1
2... Granular material, 13... Immersion tank, 14... Physiologically active substance, 15... Stirrer, l 7... Pl1 adjustment liquid.

Claims (2)

[Claims] (1) An agricultural material characterized in that crystals made of a calcium phosphate compound carrying a physiologically active substance are formed on the surface of granules that are poorly soluble in water. (2) A granular material that is sparingly soluble in water is brought into contact with a phosphorus-containing liquid in the presence of calcium and an alkali to form crystals made of a calcium phosphate compound on the surface of the granular material, and then further immersed in a physiologically active substance-containing liquid. A method for producing agricultural materials characterized by: