JP5941344B2 - Compounding agent, seaweed bed structure, vegetation structure, and method for producing compounding agent - Google Patents

Description

  The present invention relates to a compounding agent, a seaweed bed structure, a vegetation structure, and a method for producing the compounding agent.

  Recovering phosphorus resources from waste has become an important issue in Japan, which is 100% dependent on foreign countries for phosphorus ore, which is necessary for the production of phosphorus fertilizer and industrial phosphoric acid. In particular, phosphorus concentrated in sewage sludge may account for 30% or more of imported phosphorus ore, and various attempts have been made to produce fertilizers containing phosphorus from sewage sludge.

  For example, in Patent Document 1, the total phosphoric acid concentration of raw material incineration ash is measured, and when the total phosphoric acid concentration is lower than a predetermined target product concentration, the addition of high phosphorus-containing waste before melting treatment A method is disclosed in which a proportion is obtained, added to the raw material, melted, and then rapidly cooled to produce phosphorus fertilizer.

  The present applicant has also proposed a method for producing a fertilizer that adjusts the dissolution rate of phosphorus by adding a skeletal modifier to phosphorus-containing sludge or phosphorus-containing incinerated ash and melting it (Japanese Patent Application No. 2011-101289). ).

JP 2006-1819 A

However, if phosphorus and iron are included in the material to be melted such as sewage sludge, for example, in the form of iron phosphate, some phosphorus reacts with iron by the melting treatment, and iron (Fe) and iron phosphide It has been found that a solid solution containing (Fe ₂ P) is mixed into the slag as a metal component. The solid solution is a solid solution in which two or more kinds of metals are melted together to form a uniform solid phase as a whole.

  When the metal component is oxidized, the color is changed to brown. Therefore, it is difficult to reuse slag having a high mixing rate of the metal component for cement material, concrete aggregate, or the like. Further, when such slag is used as a raw material for phosphoric acid fertilizer, the phosphorus component eluted in the soil is re-adsorbed by iron, so that there is a problem that the effectiveness as the phosphorous fertilizer is hindered.

  Therefore, if such a metal component is separated and removed from the slag, the slag can be effectively used as an aggregate or fertilizer. However, since the metal component separated from the slag has not been found to be useful other than being used in a small amount as a weight material, at present, the metal component must be disposed of in a landfill. It is desired to develop its use from the viewpoint of resource recovery.

  For example, it can be used as a raw material for iron making, but since it is not a situation where such metal components are always produced in a certain amount and with a certain property, there is a possibility that the quality of the iron may fluctuate. Not in the situation. In addition, since iron phosphide in the metal component has a low energy level and is very stable, in order to utilize the phosphorus component, a large amount of reducing agent is required for the process and the cost is very high. There is also a problem.

  In view of the above-described problems, an object of the present invention is to provide a compounding agent capable of effectively utilizing iron phosphide separated from slag, a seaweed bed structure, a vegetation structure, and a method for producing the compounding agent.

In order to achieve the above-mentioned object, the first characteristic constitution of the compounding agent according to the present invention is the iron component and phosphorus necessary for rooting or growing algae or aquatic plants as described in claim 1. It is used as a component source, is recovered from crushed slag, and includes a solid solution containing iron and iron phosphide .

When a compound containing a solid solution containing iron and iron phosphide is fertilized in a fluid environment such as water, the phosphorus component eluted from iron phosphide is not adsorbed to the iron component unlike soil. Therefore, the effect as a phosphorus fertilizer is not hindered, and the iron component can be supplied as an important nutrient source such as algae.

  As described in claim 2, the second characteristic configuration is that, in addition to the first characteristic configuration described above, the iron phosphide is derived from sewage or human waste. Sewage or human waste containing a large amount of can be used very effectively as a raw material for the compounding agent.

In the third feature configuration, as described in claim 3, in addition to the first or second feature configuration described above, the iron phosphide is a melt containing a phosphate and an iron-based flocculant. Efficient supply of compounding agent because iron phosphide is easily generated and mixed in the slag obtained by melting the material to be melted containing phosphate and iron-based coagulant. The source.

The characteristic configuration of the seaweed bed structure according to the present invention is, as described in claim 4 , the compounding agent having any one of the first to third characteristic configurations described above is carried on the structure so that the fertilization effect can be adjusted. There is in point.

  With such an algae place structure, fertilizer components that are well balanced not only for plants but also for microorganisms will be eluted in an appropriate amount at an appropriate time, so that algae or aquatic plants can be efficiently rooted or cultivated. Will come to do. In addition, the seaweed bed structure is a concept that includes blocks with functions such as wave-dissipation and revetment, in addition to structures such as submerged seaweeds that grow in coastal shallows and concrete blocks that are placed in seaweed communities. It is.

The characteristic configuration of the vegetation structure according to the present invention is, as described in claim 5 , wherein the compounding agent having any one of the first to third characteristic configurations described above is supported on the structure so that the fertilization effect can be adjusted. There is in point.

  With such a vegetation structure, fertilizer components that are well-balanced for the plant are eluted in an appropriate amount at an appropriate time, so that algae or aquatic plants can be efficiently rooted or grown. The vegetation structure is a concept including an underwater planter, a river slope block, a river bottom laying block, and the like.

The first characteristic configuration of the method for producing a compounding agent according to the present invention is, as described in claim 6 , a melting treatment step for melting a material to be melted containing a phosphorus component and an iron component, and melting in the melting treatment step. A separation step of separating the solid solution containing iron and iron phosphide from the crushed slag obtained by crushing the slag solidified in the cooling treatment step, The solid solution separated in the step is used as a source of iron components and phosphorus components necessary for rooting or growing algae or aquatic plants.

In the second characteristic configuration, as described in claim 7, in addition to the first characteristic configuration described above, a material to be melted containing a phosphorus component and an iron component melted in the melting treatment step is biologically processed. Is sewage sludge that has been subjected to solid-liquid separation after phosphorus is taken in by the addition of iron-based flocculant, and the separation step crushes the slag solidified in the cooling treatment step into a predetermined particle size by a granulating mechanism. However, the solid solution is separated from the slag by any one of magnetic sorting, sieve sorting or specific gravity sorting.

  As described above, according to the present invention, it is possible to provide a compounding agent that can effectively use iron phosphide separated from slag, a seaweed bed structure, a vegetation structure, and a method for producing the compounding agent. It was.

Block diagram of fertilizer manufacturing equipment Illustration of fertilizer manufacturing method

Hereinafter, the compounding agent, seaweed bed structure, vegetation structure, and method for producing the compounding agent according to the present invention will be described.
FIG. 1 shows a compounding agent production plant 10 in which the compounding agent production method is carried out.

  The production plant 10 includes a water treatment facility 11, a dehydrating device 12, a drying device 13, a melting facility 14, a granulating device 17, a sorting device 18, and the like.

  The water treatment facility 11 includes a single or a plurality of biological treatment tanks for biologically treating sewage flowing from outside under anaerobic and / or aerobic conditions using an activated sludge method, a membrane separation activated sludge method, or the like. . In the biological treatment tank, organic substances in sewage are decomposed and removed by activated sludge and purified.

  In the process of aerobic treatment of sewage in the former biological treatment tank, phosphorus is incorporated into the activated sludge together with iron contained in the sewage, and iron-based flocculants such as polyiron and salt iron are added in the latter biological treatment tank Then, the phosphorus component is precipitated as agglomerated sludge together with the iron-based aggregating agent, and the precipitated sludge is extracted by the pump P.

  The sewage sludge containing the phosphorus component and the iron component is sent to a dehydrating device 12 such as a screw press or a filter press, and dehydrated by the dehydrating device 12 to become a dehydrated cake having a water content of about 80%. It is dried to about 20-40%.

  The dehydrated cake adjusted to a predetermined moisture content by the drying device 13 is melted by the melting equipment 14. In the melting facility 14, the sewage sludge supplied between the inner cylinder and the outer cylinder is supplied to the furnace chamber in the inner cylinder by a cutting device in which the inner cylinder and the outer cylinder rotate relative to each other, and the combustion installed in the ceiling portion It is composed of a rotary surface melting furnace that is melted from the surface by a burner and in which molten slag is dropped downward from a spout formed in the center of the floor.

  A cooling water tank 15 is disposed below the outlet, and the slag dripped into the water tank 15 is rapidly cooled to form a granulated slag, which is carried out to the granulating device 17 by the belt-type transport mechanism 16.

In the slag, iron phosphide (Fe ₂ P) in which part of iron (Fe) and phosphorus (P) is combined is generated in the melting process, and iron (Fe) and iron phosphide (Fe ₂ P) are mainly used. A solid solution containing iron phosphide (hereinafter simply referred to as “solid solution”) containing a small amount of impurities and having a uniform solid phase as a whole is mixed, and the particle size adjustment mechanism 17 reduces the particle size to 2 to 3 mm. The slag that has been crushed and sized is conveyed to the sorting mechanism 18, and the solid solution is separated from the slag. As the sorting device 18, a magnetic sorting device that adsorbs magnetic metals including a solid solution is used. As the sorting device 18, a sieve sorting device for sorting a solid solution containing iron and being hard and not crushed and a slag having a smaller particle size, or a specific gravity sorting device for sorting a solid solution and a slag having a smaller specific gravity. May be used.

  The melting equipment 14 in which the melting process step is performed is preferably a rotary surface melting furnace, but may be a swivel melting furnace or a coke bed furnace, which makes operation difficult, but other types of melting furnaces. But it is possible.

  That is, as shown in FIG. 2, a melting treatment step for melting a material to be melted containing a phosphorus component and an iron component is executed in the above-described melting equipment 14, and the slag melted in the melting treatment step is cooled in a water tank 15. A cooling process step for processing and solidifying is performed, and a separation step for separating a metal component including a solid solution from the slag solidified in the cooling process step is performed in the sorting device 18. Although the cooling process step has been described with water cooling, other cooling methods such as air cooling may be used.

  The solid solution separated in the separation step becomes a compounding agent used as a source of iron and phosphorus components necessary for rooting or growing algae or aquatic plants, and with other nutrients such as silicon, copper, zinc and manganese as appropriate. Used as a fertilizer by blending.

  Unlike fertilizers, the concentration of a compound containing a solid solution increases when the fertilizer is applied in an environment with good fluidity and diffusibility, such as water, because the phosphorus and iron components diffuse without staying in place. Because the phosphorus and iron components eluted from the solid solution flow before they are adsorbed and insolubilized without causing damage due to excessive nutrients, the effectiveness as a phosphorus fertilizer is not hindered, and the iron components are also algae It can be supplied as an important nutrient source.

  Therefore, even if it is a solid solution that may not function effectively as fertilizer in the soil, it can be used for fluidity, such as submerged seaweed and seaweed that grow in shallow seaweed beds on the coast of the sea, and aquatic plants that grow on riverbanks. It can be used as a useful nutrient in a good environment.

  Such a blended fertilizer may be applied directly to a seaweed bed or the like, or may be disposed on a seaweed bed, riverbank, etc. as a seaweed bed structure or a vegetation structure. The seaweed bed structure can be composed of a concrete block structure such as a wave-dissipating block supported in a state where the fertilizer containing the compounding agent can be eluted.

  Moreover, the porous granular support | carrier which carry | supported the said compounding agent may be formed integrally in the concrete block, and may be formed integrally in the concrete block surface layer. It is also possible to form a structure in which the compounding agent is filled in a bag-like container formed of a synthetic resinous cloth and fastened with a rope or the like. The compounding agent can be further finely pulverized, mixed with a paint, and applied to the surface of the concrete block. It is possible to adjust the fertilization effect, that is, to adjust the elution rate, by the method of loading the blended fertilizer on the structure. The elution rate can also be adjusted by adjusting the particle size of the solid solution. When the particle size is made finer, the elution rate becomes faster, and when the particle size is made larger, the elution rate becomes slower.

  As vegetation structures, concrete blocks and ceramic blocks for river slopes, concrete blocks laid on the bottom of rivers, etc. can be realized. Also in this case, the porous granular carrier carrying the compounding agent may be integrally formed inside the concrete block, or may be integrally formed on the concrete block surface layer. It is also possible to form a structure in which the compounding agent is filled in a bag-like container formed of a synthetic resinous cloth and fastened with a rope or the like. It is possible to adjust the fertilization effect, that is, to adjust the elution rate, by the method of loading the blended fertilizer on the structure.

  In any case, since fertilizer components that are well-balanced for the plant are eluted in an appropriate amount at an appropriate time, algae or aquatic plants are efficiently rooted or grown. It is also possible to embody a seaweed bed structure or a vegetation structure as an underwater planter formed by mixing a fertilizer containing the compounding agent with cement or ceramics.

  The slag from which the solid solution has been separated can be used as a phosphorus compounding agent for terrestrial plants, or as an aggregate or cement material such as concrete or asphalt.

  In the above-described embodiment, the example in which the sewage sludge is directly melted by the melting equipment 14 has been described. However, the sludge incineration ash and fly ash that have been incinerated in advance in the sludge incinerator may be melted by the melting equipment 14. .

  In the embodiment described above, an example in which the solid solution is obtained by melting sewage sludge has been described, but the solid solution can also be obtained by melting the urine sludge. That is, the solid solution is derived from sewage or human waste. The human waste includes those derived from livestock.

  Each of the embodiments described above is an example of the present invention, and the present invention is not limited by the description, and the specific configuration of the seaweed bed structure or the vegetation structure has the effects of the present invention. Needless to say, the design can be changed as appropriate within the range of performance.

10: Production plant 11: Water treatment facility 12: Dehydration device 13: Drying device 14: Melting facility 15: Water tank 16: Conveying mechanism 17: Granulating device 18: Sorting mechanism

Claims (7)

A compounding agent that is used as a source of iron and phosphorus components necessary for rooting or growing algae or aquatic plants, and that is recovered from crushed slag and contains a solid solution containing iron and iron phosphide .   The compounding agent according to claim 1, wherein the iron phosphide is derived from sewage or human waste. The compounding agent of Claim 1 or 2 obtained by isolate | separating the to-be-melted material in which the said iron phosphide contains a phosphate and an iron type coagulant | floc from the crushed slag which carried out the melt process . A seaweed bed structure in which the compounding agent according to any one of claims 1 to 3 is supported on the structure so as to be capable of adjusting fertilization. A vegetation structure in which the compounding agent according to any one of claims 1 to 3 is supported on the structure so as to be capable of adjusting fertilization. A melt treatment step for melting a melt containing a phosphorus component and an iron component;
A cooling process step of cooling and solidifying the slag melted in the melting process step;
A separation step of separating a solid solution containing iron and iron phosphide from crushed slag obtained by crushing the slag solidified in the cooling treatment step;
Including
Said separated in separation step the solid solution, a manufacturing method of a compounding agent used as a source of iron Ingredients and phosphorus components required for rooting or growth of algae or aquatic plants. The material to be melted containing the phosphorus component and the iron component melted in the melt treatment step is sewage sludge in which phosphorus is taken in by biological treatment and solid-liquid separated after the iron-based flocculant is added,
The separation step is configured to crush the slag solidified in the cooling treatment step into a predetermined particle size by a sizing mechanism, and to separate the solid solution from the slag by any one of magnetic sorting, sieve sorting, or specific gravity sorting. The manufacturing method of the compounding agent of Claim 6.

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