WO2020122068A1 - Procédé de fabrication d'engrais pour eau naturelle, et engrais pour eau naturelle - Google Patents

Procédé de fabrication d'engrais pour eau naturelle, et engrais pour eau naturelle Download PDF

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Publication number
WO2020122068A1
WO2020122068A1 PCT/JP2019/048290 JP2019048290W WO2020122068A1 WO 2020122068 A1 WO2020122068 A1 WO 2020122068A1 JP 2019048290 W JP2019048290 W JP 2019048290W WO 2020122068 A1 WO2020122068 A1 WO 2020122068A1
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Prior art keywords
fertilizer
solid
natural water
phosphorus
liquid
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PCT/JP2019/048290
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English (en)
Japanese (ja)
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熙濬 金
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国立大学法人新潟大学
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Priority to JP2020559254A priority Critical patent/JP7467798B2/ja
Publication of WO2020122068A1 publication Critical patent/WO2020122068A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
    • B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
    • B09B5/00—Operations not covered by a single other subclass or by a single other group in this subclass
    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05B—PHOSPHATIC FERTILISERS
    • C05B13/00—Fertilisers produced by pyrogenic processes from phosphatic materials
    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
    • C05D9/00—Other inorganic fertilisers
    • C05D9/02—Other inorganic fertilisers containing trace elements
    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
    • C05F7/00—Fertilisers from waste water, sewage sludge, sea slime, ooze or similar masses
    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
    • C05G1/00—Mixtures of fertilisers belonging individually to different subclasses of C05
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
    • Y02A40/20—Fertilizers of biological origin, e.g. guano or fertilizers made from animal corpses

Definitions

  • the present invention relates to a method for producing a fertilizer for natural water and a fertilizer for natural water.
  • An object of the present invention is to provide a fertilizer for natural water, which contains phosphorus, silicon and iron, and has a sufficiently low heavy metal content while effectively utilizing sludge ash, and also to manufacture the fertilizer for natural water.
  • a fertilizer for natural water which contains phosphorus, silicon and iron, and has a sufficiently low heavy metal content while effectively utilizing sludge ash, and also to manufacture the fertilizer for natural water.
  • a method In particular, it is to provide a fertilizer for natural water in which the elution rate of fertilizer components is suitably controlled, and to provide a method for producing the fertilizer for natural water.
  • the method for producing a fertilizer for natural water of the present invention comprises a first dissolution step of mixing sludge ash and an acidic liquid to dissolve heavy metals and phosphorus contained in the sludge ash, A first solid-liquid separation step of separating and removing the first liquid in which the heavy metal and phosphorus are dissolved from the first solid; A reactive ionic substance adding step of adding a reactive ionic substance which is a hydroxide and/or a salt of an alkali metal and/or a Group 2 element to the first solid; And a firing step of subjecting the composition containing the first solid and the reactive ionic substance to a firing treatment.
  • the reactive ionic substance is preferably a hydroxide and/or salt containing Na and/or Ca.
  • the reactive ionic substance is one selected from the group consisting of Na 2 CO 3 , NaOH, CaCO 3 , Ca(OH) 2 , CaCl 2 and NaCl, or It is preferable that there are two or more kinds.
  • the firing temperature in the firing treatment is preferably 150°C or higher and 1100°C or lower.
  • the treatment time of the calcination treatment is 0.5 hours or more and 100 hours or less.
  • the method for producing a fertilizer for natural water of the present invention preferably has a reducing step in which a reducing agent is added to the first solid to carry out a reducing treatment.
  • the method for producing a fertilizer for natural water of the present invention preferably further comprises an N component addition step of adding a nitrogen-based fertilizer component into the system after the first solid-liquid separation step.
  • the method for producing a fertilizer for natural water of the present invention preferably further comprises a P component addition step of adding a phosphorus fertilizer component into the system after the first solid-liquid separation step.
  • the phosphorus-based fertilizer component is A first precipitation step in which the first liquid separated in the first solid-liquid separation step is mixed with a precipitant and the pH is raised, and a second solid containing the heavy metal and phosphorus is precipitated.
  • the phosphorus-based fertilizer component mixes the second liquid with a precipitating agent to lower the pH after the third solid-liquid separation step to reduce phosphorus. It is preferably obtained by using a method further having a second precipitation step of precipitating a third solid containing the same.
  • the pH of the liquid phase at the end of the second precipitation step is preferably 2.0 or more and 12.0 or less.
  • an acidic liquid having a pH of ⁇ 1.0 or more and 2.0 or less in the second precipitation step.
  • the fertilizer for natural water of the present invention uses sludge ash as a raw material, Contains phosphorus, silicon and iron, It is characterized in that the content of heavy metals is 1000 ppm or less.
  • the phosphorus content is 1.0% by mass or more and 10% by mass or less
  • the content of silicon is 10% by mass or more and 50% by mass or less
  • the iron content is preferably 1.0% by mass or more and 50% by mass or less.
  • the phosphorus content is XP [mass %]
  • the silicon content is X Si [mass %]
  • the iron content is X Fe [mass %] 1. It is preferable to satisfy the relations of 0 ⁇ X Si /X P ⁇ 50.0 and 0.9 ⁇ X Fe /X P ⁇ 50.0.
  • the present invention while effectively utilizing sludge ash, providing phosphorus, silicon and iron, and to provide a fertilizer for natural water having a sufficiently low content of heavy metals, also the production of the fertilizer for natural water A method can be provided.
  • FIG. 1 is a process diagram showing a preferred embodiment of the method for producing a fertilizer for natural water of the present invention.
  • FIG. 2 is a diagram schematically showing the relationship between the pH of the liquid phase at the end of the first precipitation step and the final phosphorus recovery rate.
  • FIG. 3 is a diagram showing changes over time in the elution rate of iron and the like when sludge ash (Comparative Example 1) is treated with hydrochloric acid.
  • FIG. 4 shows the relationship between the number of days elapsed from the addition of sodium carbonate to the aqueous solution of sodium chloride and the elution rate of phosphorus components with respect to the natural water fertilizers of Examples 1 to 5 and Comparative Example 1. It is a figure.
  • FIG. 1 is a process diagram showing a preferred embodiment of the method for producing a fertilizer for natural water of the present invention.
  • FIG. 2 is a diagram schematically showing the relationship between the pH of the liquid phase at the end of the first precipitation step and the final phospho
  • FIG. 5 is a diagram showing the correspondence between the pH of the liquid phase at the end of the first precipitation step and the X-ray diffraction (XRD) pattern of the precipitates for Examples 6, 7 and 8.
  • FIG. 6 shows the recovery rate of phosphorus and main metal elements (that is, the amount relative to the amount contained in sludge ash as a raw material) for the third solid obtained in the process for producing the fertilizer for natural water of Example 6.
  • 3 is a graph showing the ratio of the amount contained in the solid of No. 3).
  • FIG. 7 is a graph showing the results of the water solubility test and the water solubility test for the third solid obtained in the process of producing the fertilizer for natural water of Example 6.
  • FIG. 6 shows the recovery rate of phosphorus and main metal elements (that is, the amount relative to the amount contained in sludge ash as a raw material) for the third solid obtained in the process for producing the fertilizer for natural water of Example 6.
  • 3 is a graph showing the ratio of the amount contained in the
  • FIG. 8 is a flowchart showing a specific example of the method for producing a fertilizer for natural water of the present invention.
  • FIG. 9 is a graph showing the relationship between the number of days elapsed from addition to the aqueous sodium chloride solution and the elution rate of phosphorus components with respect to the fertilizers for natural water according to Examples 11 to 16 with respect to changes in firing temperature.
  • FIG. 10 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous solution and the elution rate of the phosphorus component with respect to the change in the addition amount of calcium carbonate in the fertilizers for natural water according to Examples 17 and 18.
  • FIG. 9 is a graph showing the relationship between the number of days elapsed from addition to the aqueous sodium chloride solution and the elution rate of phosphorus components with respect to the fertilizers for natural water according to Examples 11 to 16 with respect to changes in firing temperature.
  • FIG. 10 is a diagram showing the relationship between the
  • FIG. 11 is a diagram showing the relationship between the number of days elapsed from addition to the sodium chloride aqueous solution and the elution rate of phosphorus components with respect to changes in the firing time for the fertilizers for natural water according to Examples 19 and 20.
  • FIG. 12 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous solution and the elution rate of the iron component with respect to the presence or absence of addition of sodium hydroxide in the fertilizers for natural water according to Example 21 and Comparative Example 2. is there.
  • FIG. 12 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous solution and the elution rate of the iron component with respect to the presence or absence of addition of sodium hydroxide in the fertilizers for natural water according to Example 21 and Comparative Example 2. is there.
  • FIG. 12 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous
  • FIG. 13 is a figure which shows the relationship between the elapsed days after addition to the sodium chloride aqueous solution and the elution rate of an iron component with respect to the change of the addition amount of sodium hydroxide about the fertilizer for natural waters which concerns on Example 22 and 23. ..
  • FIG. 14 is a diagram showing the relationship between the number of days elapsed from addition to the aqueous sodium chloride solution and the elution rate of the iron component with respect to changes in the firing temperature for the fertilizers for natural water according to Examples 24 and 25.
  • FIG. 15 shows the relationship between the number of days elapsed from the addition of the reactive ionic substance to the sodium chloride aqueous solution and the elution rate of the silicon component with respect to the natural water fertilizers of Examples 26 to 28 and Comparative Example 3. It is a figure.
  • FIG. 16 is a diagram showing the relationship between the number of days elapsed from addition to the sodium chloride aqueous solution and the elution rate of silicon components with respect to changes in the firing temperature, for the fertilizers for natural water according to Examples 29 to 31.
  • FIG. 16 is a diagram showing the relationship between the number of days elapsed from addition to the sodium chloride aqueous solution and the elution rate of silicon components with respect to changes in the firing temperature, for the fertilizers for natural water according to Examples 29 to 31.
  • FIG. 17 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous solution and the elution rate of the silicon component with respect to the change in the addition amount of sodium ions in the fertilizers for natural water according to Examples 32 and 33.
  • FIG. 18 is a diagram showing the relationship between the number of days elapsed from the addition to the sodium chloride aqueous solution and the elution rate of the silicon component with respect to the change in the addition amount of calcium ions in the fertilizers for natural water according to Examples 34 and 35.
  • FIG. 1 is a process diagram showing a preferred embodiment of the method for producing a fertilizer for natural water of the present invention.
  • FIG. 2 is a diagram schematically showing the relationship between the pH of the liquid phase at the end of the first precipitation step and the final phosphorus recovery rate.
  • the method for producing a fertilizer for natural water of the present invention comprises mixing a sludge ash and an acidic liquid to dissolve a heavy metal and phosphorus contained in the sludge ash, and a first dissolving step in which the heavy metal and phosphorus are dissolved.
  • a first solid-liquid separation step of separating and removing the liquid of No. 1 from the first solid; and a reaction of being a hydroxide and/or salt of an alkali metal and/or a Group 2 element with respect to the first solid.
  • the method is characterized by including a reactive ionic substance addition step of adding a cationic ionic substance and a firing step of subjecting the composition containing the first solid and the reactive ionic substance to a firing treatment.
  • sludge ash As a raw material in this way, sludge ash that has been conventionally treated as industrial waste can be effectively used for unprecedented applications, and it is possible to save resources and to reclaim industrial waste. This is preferable from the viewpoints of securing a site and reducing the overall sludge ash treatment cost.
  • most of the sludge ash (for example, a portion occupying about 90% by volume) can be effectively used as a fertilizer for natural water, so the effect from the above viewpoint is very large.
  • the sludge ash also contains iron and silicon at a high content rate, and a fertilizer for natural water containing these components in a well-balanced manner can be suitably obtained.
  • the solubility of fertilizer components such as a silicon component and an iron component, in addition to the phosphorus component contained in the fertilizer for natural waters can be improved suitably.
  • the elution rate of fertilizer components from the fertilizer for natural water produced can be adjusted by adjusting the type and amount of reactive ionic substance used in the reactive ionic substance addition step and the firing treatment conditions in the firing step. It can be controlled appropriately.
  • the fertilizing effect of fertilizer components can be controlled over a wide range of several days to several years.
  • the amount of sodium carbonate added was changed from 15% by weight to 35% by weight, and natural water fertilizer sintered at 900° C. contained 50% phosphorus.
  • the time required for elution is 2 days at 35% by weight, but 350 days at 15%.
  • phosphorus elution rate 50% when the amount of calcium carbonate added to the first solid is 20% by weight and when 10% by weight is compared, It's 300 days. 10% requires 1500 days. That is, for example, by changing the production conditions within the above range, the fertilizing effect of the fertilizer component can be suitably controlled in a wide range of 2 days to 1500 days.
  • the elution rate of fertilizer components from natural water fertilizers can be made relatively small, and the sustainability of natural water fertilizers can be increased. ..
  • the elution rate of the fertilizer component from the fertilizer for natural water can be relatively increased, and the immediate effect of the fertilizer for natural water can be enhanced.
  • the sintering temperature is from 600° C. to 900° C.
  • the phosphorus elution rate increases with increasing temperature, but when it exceeds 900° C., the elution rate decreases.
  • the first liquid separated in the first solid-liquid separation step contains a high content of phosphorus, it is possible to suitably obtain a highly pure phosphorus compound by purifying the first liquid. You can Therefore, the phosphorus contained in the sludge ash can be used as a whole with particularly high efficiency.
  • a composition containing the heavy metal in a relatively high concentration It is possible to significantly reduce the volume, and it is preferable from the viewpoints of securing a site for treating industrial waste and controlling harmful substances.
  • the heavy metal means a metal having a specific gravity of 4 or more and excluding iron.
  • natural water includes sea, rivers, lakes, ponds, swamps, and other water that exists collectively in the natural world, and in addition, artificially created artificial ponds, reservoirs, The concept also includes water existing in a closed space that is not directly connected to the sea, rivers, lakes, ponds, swamps, etc., such as fishing ponds, aquariums, and farms.
  • natural water includes irrigation water.
  • the natural water may be any of fresh water, salt water, and brackish water.
  • the natural water to which the fertilizer for natural water according to the present invention is applied is preferably seawater.
  • the sea is prone to malnutrition and the so-called desertification of the sea is also progressing. Therefore, when the natural water is seawater, the effect of the present invention is more remarkably exhibited.
  • the ecosystem By stopping the desertification of the sea, the ecosystem can be restored.
  • the fertilizer for natural water according to the present invention it is possible to supply nutrients to the sea, improve the growth of seaweeds such as kelp and seaweed, and become a place for growing fish.
  • seaweed can be used as a feed for abalone, turban shell, etc.
  • the production amount of high-grade food such as abalone, turban shell, etc. will also increase. That is, it can contribute to the economic vitalization of the fishing village.
  • a N component addition step of adding a nitrogen-based fertilizer component into the system is further provided after the first solid-liquid separation step.
  • the content rate of the phosphorus-based fertilizer component in the fertilizer for natural water can be adjusted to a suitable value.
  • a fertilizer for natural water containing a plurality of phosphorus-based fertilizer components having different solubilities in water can be suitably prepared.
  • composition containing the phosphorus-based fertilizer component added to the first solid in the P component addition step will be described in detail later. Further, in the present embodiment, in the P component addition step, the composition containing the reactive ionic substance is added together with the phosphorus-based fertilizer component. In other words, the P component addition step also serves as the reactive ionic substance addition step.
  • the phosphorus-based fertilizer component can be supplied to the first solid while supplying the reactive ionic substance, and the productivity of the fertilizer for natural water can be made excellent, while the phosphorus-based fertilizer component can be supplied. It is possible to obtain a fertilizer for natural water, the content of which is controlled and the elution rate of fertilizer components being controlled more suitably.
  • the reactive ionic substance addition step may be performed directly on the first solid obtained in the first solid-liquid separation step, or in the first solid-liquid separation step. It may be performed after subjecting the solid to a predetermined treatment.
  • the step of adding the reactive ionic substance is performed before the firing step described in detail later.
  • the firing step is performed after the reactive ionic substance addition step.
  • the sparingly soluble components for example, phosphorus component, silicon component, iron component, etc.
  • the sparingly soluble components for example, phosphorus component, silicon component, iron component, etc.
  • the solubility of the phosphorus component, silicon component, iron component, etc. contained in the fertilizer for use can be more suitably adjusted.
  • x, y, z, l, m and n are integers of 1 or more.
  • the soluble salt is added to calcium-deficient hydroxyapatite, CaHPO 4 , Ca(H 2 PO 4 ) 2 , Ca 8 (HPO 4 ) 2 , Na. It can also be obtained as hydrogen phosphate such as 2 HPO 4 and NaH 2 PO 4 .
  • x, y, a, b, c, d and e are each an integer of 1 or more, and M is a metal element.
  • the reactive ionic substance added in the reactive ionic substance addition step is the one used in the second precipitation step described in detail later.
  • the method for producing a fertilizer for natural water of the present invention may have a reducing step in which a reducing agent is added to the first solid, which is a treated product of sludge ash, to carry out a reducing treatment.
  • the solubility of the phosphorus component, etc. contained in the fertilizer for natural water can be increased more suitably.
  • the first solid contains iron, silicon, etc.
  • the elution rate of fertilizer for natural water finally obtained can be suitably controlled.
  • the reduction step may be performed directly on the first solid obtained in the first solid-liquid separation step, or may be performed on the first solid obtained in the first solid-liquid separation step by a predetermined treatment. It may be performed after the above.
  • the reducing step can be performed using, for example, a reducing agent containing carbon, hydrogen and the like. Also, a method of mixing and reducing agricultural and forestry wastes such as rice husks and the like can be adopted.
  • the reducing agent containing carbon include graphite and carbon black.
  • the reducing step may be performed at any timing, but for example, it is preferable to perform it at a timing after the reducing agent addition process after elution and removal of heavy metals and phosphorus from sludge ash. Furthermore, the reduction step and the firing step may be performed simultaneously by performing the firing step in the absence of oxygen.
  • a firing step of performing a firing treatment on the composition containing the first solid and the reactive ionic substance is performed after the first solid-liquid separation step and the reactive ionic substance addition step. Have more.
  • the amount of water contained in the fertilizer for natural water can be suitably reduced.
  • the solubility and the like of the fertilizer for natural water in water can be suitably adjusted.
  • the P component addition step, the firing step and the N component addition step are performed in this order after the first solid-liquid separation step, but the order of these steps may be changed. Alternatively, a plurality of steps may be simultaneously performed.
  • First dissolution step In the first dissolution step, sludge ash and an acidic liquid are mixed. This dissolves heavy metals and phosphorus contained in the sludge ash.
  • phosphorus is usually contained in the form of oxides (P 2 O 5 etc.), phosphoric acid, phosphates and the like.
  • oxides P 2 O 5 etc.
  • phosphoric acid phosphoric acid
  • phosphates phosphates
  • a compound (including an ionic substance) containing phosphorus as an atom including these forms and a phosphorus atom contained in the compound may be simply referred to as phosphorus.
  • heavy metals are contained in the sludge ash in the form of metal oxides (including complex oxides), simple metals, alloys, metal salts, etc.
  • metal oxides including complex oxides
  • simple metals simple metals
  • alloys metal salts
  • a heavy metal atom contained in the compound may be simply referred to as a heavy metal.
  • Sludge ash used in this process (that is, sludge ash as a raw material for fertilizer for natural water) generally contains iron and silicon in addition to heavy metals and phosphorus. Then, in this step, while heavy metals can be efficiently dissolved, in addition to iron and silicon, part of phosphorus in the sludge ash remains in the solid content without being dissolved.
  • the sludge ash used in this step (that is, the sludge ash as a raw material for fertilizer for natural water) generally contains Al, Mg, etc. in addition to the above components.
  • metals other than heavy metals can be dissolved.
  • a part of iron contained in sludge ash is dissolved.
  • These components function as impurities in the first precipitation step, which will be described in detail later, and form crystals of phosphate (particularly, calcium hydrogen phosphate dihydrate, calcium phosphate such as calcium phosphate). Coarsening can be prevented more effectively.
  • the phosphate crystals that are formed are relatively unstable and are readily soluble in alkaline liquids.
  • the phosphate can be dissolved with higher selectivity in the second dissolution step described in detail later.
  • the acidic liquid used in this step is not particularly limited, but a strong acid having a pH (hydrogen ion index) of ⁇ 1.0 or more and 2.0 or less is preferable.
  • the amount of acidic liquid used can be suppressed and this process can be performed efficiently. Further, it is possible to effectively prevent the volume of the composition (that is, the mixture of sludge ash and acidic liquid) after the treatment in this step from becoming too large. It is also preferable from the viewpoint of ease of subsequent steps and reduction of the amount of waste liquid to be treated.
  • the pH of the acidic liquid used in this step is preferably -1.0 or more and 1.5 or less, more preferably -0.5 or more and 1.3 or less, and 0 or more and 1.0 or less.
  • the following is more preferable. As a result, the effects described above are more significantly exhibited.
  • the acidic liquid for example, sulfuric acid, nitric acid, acetic acid, hydrochloric acid, or a liquid containing two or more of these can be used.
  • the pH of the liquid phase (that is, the first liquid in which the heavy metal and phosphorus are dissolved) at the end of this step is preferably 0.5 or more and 6.8 or less, and particularly 1.0 or more and 6.5. It is more preferably the following or less, and even more preferably 1.5 or more and 6.0 or less.
  • the dissolution rate of phosphorus in the liquid phase at the end of this step is not particularly limited, but is preferably 10% or more and 99% or less, more preferably 15% or more and 90% or less, and 20% or more. It is more preferably 70% or less. As a result, phosphorus, which is a useful substance, can be recovered more efficiently.
  • this step is preferably performed while stirring the mixture of sludge ash and an acidic liquid.
  • the sludge ash and the acidic liquid can be brought into contact with each other more efficiently, and the heavy metal or the like can be dissolved more efficiently.
  • stirring devices and various mixing devices can be used for stirring the mixture of sludge ash and an acidic liquid.
  • this step may be performed in a batch system or a continuous system.
  • First solid-liquid separation step In the first solid-liquid separation step, the first liquid in which heavy metal and phosphorus are dissolved is separated and removed from the first solid which is a solid component.
  • the first solid in which the content of phosphorus is adjusted without substantially containing heavy metals. Further, such a first solid contains, in addition to phosphorus, silicon and iron derived from sludge ash. Therefore, the first solid can be preferably used as a fertilizer for natural water or a raw material thereof.
  • the method of solid-liquid separation is not particularly limited, and examples thereof include decantation, filtration, centrifugation and the like, and a plurality of methods may be combined.
  • the solid phase (that is, the first solid) once separated may be washed with water or the like, if necessary.
  • the ionic concentration of the acid component and the heavy metal content can be lowered.
  • the liquid used for washing the solid phase may be used in the first precipitation step, which will be described in detail later, after the recovery, together with the liquid phase obtained by the solid-liquid separation.
  • the phosphorus content in the solid-liquid separated solid phase is not particularly limited, but is preferably 1.0% by mass or more and 40% by mass or less, and 2.0% by mass or more and 20% by mass or less. It is more preferably 3.0% by mass or more and 10.0% by mass or less.
  • the content of heavy metals in the solid phase separated by solid-liquid separation (when plural kinds of heavy metal elements are contained, the total amount of these elements.
  • the same applies hereinafter) is not particularly limited, but is preferably 1% by mass or less. , 0.01 mass% or less is more preferable, and 0.0001 mass% or less is further preferable.
  • the phosphorus-based fertilizer component is added in the P component addition process to the solid phase (that is, the first solid) separated in the first solid-liquid separation process.
  • the composition containing the reactive ionic substance together with the phosphorus-based fertilizer component is added to the first solid.
  • Examples of the phosphorus-based fertilizer component include a phosphoric acid-based compound recovered from sludge ash, a commercially available phosphoric acid-based fertilizer, steel-making slag, biomass burning ash, and steel slag, and one or two selected from these. A combination of two or more species can be used.
  • the phosphorus-based fertilizer component may be added in a solid state, or may be added in a solution state or a paste state.
  • the preparation of the composition added to the first solid in the P component addition step, that is, the composition containing the phosphorus-based fertilizer component and the reactive ionic substance will be described in detail later.
  • the timing of the P component addition step is not particularly limited, and for example, the P component addition step may be performed at a timing later than the firing step.
  • the composition containing the first solid and the reactive ionic substance is subjected to a firing treatment.
  • the firing process is performed after the P component addition process.
  • the firing temperature in the firing treatment is not particularly limited, but is preferably 150° C. or higher and 1100° C. or lower, more preferably 200° C. or higher and 1000° C. or lower, and further preferably 250° C. or higher and 950° C. or lower.
  • the treatment time of the firing treatment is not particularly limited, but is preferably 0.5 hours or more and 100 hours or less, more preferably 1.5 hours or more and 90 hours or less, and 2 hours or more and 80 hours or less. Is more preferable.
  • N component addition step In the N component adding step, a nitrogen-based fertilizer component is added.
  • nitrogen-based fertilizer component examples include urea, lime nitrogen, sodium nitrate, ammonium nitrate, ammonium sulfate and the like, and one or more selected from these may be used in combination.
  • the addition amount of the nitrogen-based fertilizer component is not particularly limited, but in the finally obtained natural water fertilizer, the content of nitrogen with respect to 100 parts by mass of phosphorus atoms satisfies the following conditions. Is preferred. That is, the content of nitrogen with respect to 100 parts by mass of phosphorus atoms in the finally obtained fertilizer for natural water is not particularly limited, but is preferably 1.0 part by mass or more and 30.0 parts by mass or less. It is more preferably 0 part by mass or more and 20.0 parts by mass or less, and further preferably 3.0 parts by mass or more and 10.0 parts by mass or less.
  • the nitrogen-based fertilizer component may be added in the solid state, or may be added in the solution state or paste state.
  • composition added to the first solid in the P component addition step that is, the composition containing the phosphorus-based fertilizer component and the reactive ionic substance will be described in detail.
  • the phosphorus-based fertilizer component contained in the composition added in the P component addition step is not particularly limited, and, for example, a commercially available fertilizer may be used, but obtained through a method having the following steps. Is preferred.
  • the composition added to the first solid in the P component addition step mixes the first liquid separated in the first solid-liquid separation step with the precipitant and raises the pH, and contains a heavy metal and phosphorus.
  • a first precipitation step of precipitating a second solid, a second solid-liquid separation step of separating the second solid from a liquid component, and a step of dissolving phosphorus contained in the second solid with an alkaline liquid It is preferably separated by a method having a dissolution step of No. 2 and a third solid-liquid separation step of separating the second liquid in which phosphorus is dissolved from the solid component containing heavy metal.
  • the phosphorus-based fertilizer component contained in the composition added in the P component addition step can also be derived from sludge ash, and the utilization efficiency of sludge ash can be further enhanced. Further, such a phosphorus-based fertilizer component (a phosphorus-based fertilizer component contained in the composition added in the P component addition step) is more soluble in water than the phosphorus component contained in the first solid described above. Since it is highly soluble, the solubility of the phosphorus-based fertilizer component as the whole fertilizer for natural water can be suitably adjusted, and the immediate effect and the sustainability can be compatible at a higher level.
  • the phosphorus-based fertilizer component is, after the third solid-liquid separation step, the second precipitation step of mixing the second liquid with the precipitation agent and lowering the pH to precipitate the third solid containing phosphorus. It is preferably obtained by using a method further comprising
  • the phosphate can be preferably used as a phosphorus-based fertilizer component in the P component addition step. Further, since the phosphate has high purity, it is suitable for applications other than the phosphorus-based fertilizer component used in the P component addition step.
  • phosphorus can be treated as a solid substance phosphate (for example, calcium hydrogen phosphate dihydrate, calcium phosphate, etc.), and storage and transportation can be more suitably performed.
  • First deposition step In the first precipitation step, the first liquid separated from the first solid in the first solid-liquid separation step is mixed with a precipitant and the pH is raised to remove a second solid containing heavy metal and phosphorus. Precipitate.
  • phosphorus is deposited as a phosphate (eg, calcium hydrogen phosphate dihydrate, calcium phosphate, etc.).
  • the nucleation and growth of the phosphate can be suitably controlled, and the phosphate can be precipitated as microcrystals.
  • the phosphate salt can be easily dissolved, and phosphorus (dissolved state) can be suitably separated from heavy metal (solid state).
  • the first liquid usually contains Al, Mg, and the like together with heavy metals and phosphorus, so that in this step, coarsening of the crystals of the phosphate (particularly, the calcium salt of phosphoric acid) can be prevented. It can be effectively prevented.
  • the phosphate crystals that are formed are relatively unstable and are readily soluble in alkaline liquids. Therefore, in a later step, the phosphate can be dissolved with higher selectivity.
  • any substance or composition may be used as long as it can be mixed with the precipitant and raise the pH, but it is preferable to use an alkaline liquid having a pH of 10 or more.
  • the pH of the mixture can be raised more suitably, and the second solid containing the heavy metal and phosphorus can be more efficiently precipitated.
  • the precipitant may have a function of promoting the precipitation of phosphate or the like, and examples thereof include Ca-based substances such as CaCl 2 , Ca(OH) 2 and CaCO 3 , Al-based substances such as Al salts, and Fe. Fe-based substances such as salts and Mg-based substances such as Mg salts can be used, but Ca-based substances are preferably used.
  • phosphorus can be precipitated as a calcium salt of phosphoric acid (for example, calcium hydrogen phosphate dihydrate, calcium phosphate, etc.), and the subsequent steps can be more suitably performed.
  • an alkaline liquid having a pH of 10 or more but the pH of the alkaline liquid is not particularly limited, but is preferably 11 or more, more preferably 12 or more and 14 or less.
  • an alkaline calcium compound which is selected from the group consisting of CaCl 2 , Ca(OH) 2 , CaCO 3 and chlorides having Al, Mg and Fe components. It is more preferable to use one kind or two or more kinds, and it is more preferable to use one kind or two or more kinds selected from the group consisting of CaCl 2 , Ca(OH) 2 and CaCO 3, and it is preferable to use CaCl 2. Most preferred.
  • the pH of the mixture can be appropriately adjusted while efficiently supplying the calcium component, which is a part of the calcium salt of phosphoric acid, into the system.
  • the amount of the substance mixed with the first liquid can be suppressed, and this step can proceed efficiently.
  • the balance between the calcium content and the pH in the mixture in this step can be suitably adjusted, and the content of impurities in the first liquid can be improved while improving the precipitation efficiency of heavy metals and phosphorus. Can be lowered.
  • the pH of the liquid phase at the end of this step is not particularly limited, but is preferably 1.0 or more and 12 or less, more preferably 1.5 or more and 9.0 or less, and 2.0 or more and 8. It is more preferably 0 or less.
  • the amount of phosphorus and heavy metals remaining in the liquid phase can be further reduced while preventing the amount of the material used to raise the pH from unnecessarily increasing.
  • FIG. 2 is a diagram schematically showing the relationship between the pH of the liquid phase at the end of the first precipitation step and the final phosphorus recovery rate.
  • this step it is preferable to add calcium so as to satisfy the following conditions. That is, when the amount of phosphorus in the system at the end of this step is X P [mol] and the amount of calcium in the system is X Ca [mol], 1.0 ⁇ X Ca /X P ⁇ 4.0 It is preferable that the relationship be satisfied, more preferable that the relationship 1.3 ⁇ X Ca /X P ⁇ 3.0 be satisfied, and that the relationship 1.5 ⁇ X Ca /X P ⁇ 2.5 be satisfied. Is more preferable.
  • the phosphorus contained in the first liquid can be more favorably precipitated as a calcium salt of phosphoric acid (for example, it can be deposited to almost 100%), and phosphorus remaining in the liquid phase in a dissolved state can be precipitated.
  • the ratio of can be made particularly low.
  • Such liquid phase (that is, liquid phase that does not substantially contain heavy metals and has a sufficiently low phosphorus content) has a small impact on the environment and can be drained without any problem. Further, the liquid phase obtained by solid-liquid separation may be reused in the above step. As a result, a liquid containing calcium at a relatively high content can be reused, which is preferable from the viewpoint of further effective use of resources.
  • the method of solid-liquid separation is not particularly limited, and examples thereof include decantation, filtration, centrifugation and the like, and a plurality of methods may be combined.
  • the solid phase once separated may be washed with water or the like, if necessary.
  • the phosphorus content in the solid-liquid separated liquid phase is not particularly limited, but is preferably 1000 ppm or less, more preferably 100 ppm or less, and further preferably 10 ppm or less.
  • the content of heavy metals in the liquid phase subjected to solid-liquid separation is not particularly limited, but is preferably 10,000 ppm or less, more preferably 1000 ppm or less, and further preferably 0.1 ppm or less.
  • ⁇ Second dissolution step> In the second dissolution step, phosphorus contained in the second solid is dissolved in the alkaline liquid.
  • phosphorus can be selectively dissolved while preventing the heavy metal contained in the second solid from being dissolved.
  • the nucleation and growth of the phosphate are appropriately controlled, and the phosphate is converted to alkali. It is easily dissolved.
  • heavy metals are generally difficult to dissolve in alkaline liquids.
  • phosphorus a phosphorus-based fertilizer component that can be suitably used in the P component addition step
  • the final solid waste as a useful substance that can be used for fertilizers and the like can be favorably separated from heavy metals.
  • the final solid waste (industrial waste) can be reduced.
  • the pH of the alkaline liquid used in this step is not particularly limited, but is preferably 10 or more, more preferably 11 or more and 14 or less, and further preferably 12 or more and 14 or less.
  • phosphorus phosphate
  • redissolution of heavy metals it is possible to more reliably prevent the phosphorus from being unintentionally deposited before the completion of the third solid-liquid separation step that is performed later.
  • the alkaline liquid may be any liquid that exhibits alkalinity as a whole, and examples of the alkaline substance contained in the alkaline liquid include NaOH, KOH, Mg(OH) 2 , Ca(OH) 2 , Al(OH ) 3 metal hydroxide, CaCO 3, MgCO 3 or the like of metal carbonates, ammonia, triethylamine, and amine-based materials such as aniline and the like.
  • the alkaline liquid used in this step preferably contains a metal hydroxide as an alkaline substance, more preferably contains a hydroxide of an alkali metal, and further contains NaOH. preferable.
  • phosphorus contained in the second solid can be more efficiently dissolved while preventing the redissolution of heavy metals more effectively.
  • an alkaline substance is inexpensive and easily available, and is preferable also from the viewpoint of cost reduction, stable treatment, and the like.
  • the pH of the liquid phase at the end of this step is not particularly limited, but is preferably 10 or higher, more preferably 11 or higher and 14 or lower, and even more preferably 12 or higher and 14 or lower.
  • phosphorus contained in the second solid can be more efficiently dissolved while more effectively preventing the redissolution of heavy metals, and the amount of the material used to raise the pH is increased more than necessary. While preventing this, the amount of phosphorus remaining in the liquid phase can be further reduced. In addition, it is possible to more reliably prevent undesired precipitation of phosphorus and unintentional dissolution of heavy metals before the completion of the third solid-liquid separation step later.
  • phosphorus and heavy metals can be separated.
  • heavy metals that require strict treatment can be handled as solids, handling of heavy metals becomes easy.
  • the volume of the material containing the heavy metal can be greatly reduced, for example, even when treating as industrial waste, the treatment becomes easy.
  • the separated liquid phase does not need to be treated as industrial waste because it does not substantially contain heavy metals.
  • the method of solid-liquid separation is not particularly limited, and examples thereof include decantation, filtration, centrifugation and the like, and a plurality of methods may be combined.
  • the solid phase once separated may be washed with water or the like, if necessary. As a result, the phosphorus content in the solid can be lowered.
  • liquid used for washing the solid phase may be combined with the liquid phase obtained by the above solid-liquid separation after recovery.
  • the amount of phosphorus in the solid phase separated by solid-liquid separation is not particularly limited, but is 30% by mass or less of the phosphorus content of the sludge ash used as a raw material (that is, the sludge ash used in the first dissolution step). Is preferable, 10% by mass or less is more preferable, and 2% by mass or less is further preferable. Further, the phosphorus content in the solid phase separated by solid-liquid separation is preferably 50% by mass or more, more preferably 90% by mass or more, and further preferably 99% by mass or more.
  • the content of heavy metals in the liquid phase subjected to solid-liquid separation is not particularly limited, but is preferably 1000 ppm or less, more preferably 10 ppm or less, and further preferably 0.01 ppm or less.
  • ⁇ Second deposition step> In the present embodiment, after the above-described third solid-liquid separation step, a second precipitation step of mixing the second liquid with the precipitation agent and lowering the pH to precipitate the third solid containing phosphorus is further performed.
  • the phosphate can be preferably used as a phosphorus-based fertilizer component in the P component addition step. it can. Further, since the phosphate has high purity, it is suitable for applications other than the phosphorus-based fertilizer component used in the P component addition step.
  • phosphorus can be treated as a solid substance phosphate (for example, calcium hydrogen phosphate dihydrate, calcium phosphate, etc.), and storage and transportation can be more suitably performed.
  • any substance or composition may be used as long as it can be mixed with the precipitant and can lower the pH, but it is preferable to use an acidic liquid having a pH of ⁇ 1.0 or more and 2.0 or less. preferable.
  • the pH of the mixture can be suitably lowered, and the third solid containing phosphorus can be more efficiently precipitated.
  • an acidic liquid having a pH of ⁇ 1.0 or more and 2 or less it is preferable to use an acidic liquid having a pH of ⁇ 1.0 or more and 2 or less, but the pH of the acidic liquid is more preferably ⁇ 0.5 or more and 1.3 or less, and 0.0 or more. It is more preferably 1.0 or less.
  • the precipitating agent one having a function of promoting the precipitation of phosphate or the like may be used, but a reactive ionic substance which is a hydroxide and/or a salt of an alkali metal and/or a Group 2 element. Preference is given to using substances.
  • the reactive ionic substance is preferably a hydroxide and/or salt containing Na and/or Ca.
  • the effects described above are more significantly exhibited.
  • this step it is preferable to use one or more selected from the group consisting of Na 2 CO 3 , NaOH, CaCO 3 , Ca(OH) 2 , CaCl 2 and NaCl.
  • the pH of the mixture can be adjusted appropriately.
  • the amount of the substance mixed with the second liquid can be suppressed, and this process can proceed efficiently.
  • the solubility of the phosphorus component and the like contained in the fertilizer for natural water can be adjusted more suitably.
  • the fertilizer for natural water finally obtained is provided with a salt containing Na or Ca as a soluble salt of phosphorus (alkali metal salt of phosphoric acid compound and/or salt of Group 2 element).
  • a salt containing Na or Ca as a soluble salt of phosphorus (alkali metal salt of phosphoric acid compound and/or salt of Group 2 element).
  • a salt include salts represented by Na x P y O z and Ca x P y O z (wherein each of x, y, and z is an integer of 1 or more), CaHPO 4 , and the like.
  • Examples thereof include salts of hydrogen phosphate compounds such as Ca(H 2 PO 4 ) 2 , NaH 2 PO 4 , and Na 2 HPO 4 .
  • the salt contains one or more selected from the group consisting of Na 3 PO 4 , Na 4 P 2 O 7 , and Ca 3 (PO 4 ) 2 .
  • the reactive ionic substance it is preferable to use a hydroxide and/or salt containing Na and a hydroxide and/or salt containing Ca in combination.
  • the fertilizer for natural water finally obtained can contain both the sodium salt of a phosphoric acid compound and the calcium salt of a phosphoric acid compound. Since the sodium salt of a phosphoric acid compound and the calcium salt of a phosphoric acid compound have different solubilities in water, by combining them, the solubility in natural water can be adjusted more preferably. For example, while the elution amount of the phosphorus component (soluble salt) in the initial stage after application to natural water is relatively high, the phosphorus component (solubility The elution amount of (salt) can also be made relatively high.
  • the pH of the liquid phase at the end of this step is not particularly limited, but is preferably 2.0 or more and 12.0 or less, more preferably 2.5 or more and 10.0 or less, and 3.0 or more. It is more preferably 8.0 or less.
  • this step it is preferable to add calcium so as to satisfy the following conditions. That is, when the amount of phosphorus in the system at the end of this step is X P [mol] and the amount of calcium in the system is X Ca [mol], 1.0 ⁇ X Ca /X P ⁇ 4.0 It is preferable that the relationship be satisfied, more preferable that the relationship 1.3 ⁇ X Ca /X P ⁇ 3.0 be satisfied, and that the relationship 1.5 ⁇ X Ca /X P ⁇ 2.5 be satisfied. Is more preferable.
  • the phosphorus contained in the second liquid can be more favorably precipitated as the calcium salt of phosphoric acid, and the proportion of phosphorus remaining in the liquid phase in the dissolved state can be made particularly low.
  • the separated liquid phase does not substantially contain heavy metals, there is no need to treat it as an industrial waste liquid. Moreover, since the separated liquid phase has a sufficiently low phosphorus content, even if the liquid phase is discarded, there is no disadvantage from the viewpoint of effective utilization of useful resources.
  • the separated third solid contains phosphate in a high purity and has an extremely low content of heavy metals, and thus is suitable for fertilizers (particularly, phosphorus-based fertilizer components added in the P component addition step). Can be used. In particular, even if the post-treatment or the like is not performed, or even when the post-treatment is performed, it can be suitably used for fertilizers and the like with a simple treatment.
  • the method of solid-liquid separation is not particularly limited, and examples thereof include decantation, filtration, centrifugation and the like, and a plurality of methods may be combined.
  • the solid phase once separated may be washed with water or the like, if necessary. As a result, the content of ions (cations and anions) in the solid can be lowered.
  • liquid used for washing the solid phase may be combined with the liquid phase obtained by the above solid-liquid separation after recovery.
  • the content of the heavy metal in the solid-liquid separated solid phase (second solid) is not particularly limited, but is preferably 1000 ppm or less, more preferably 500 ppm or less, and further preferably 10 ppm or less. preferable.
  • FIG. 8 shows a flowchart of a specific example of the method for producing a fertilizer for natural water of the present invention.
  • the fertilizer for natural water of the present invention is made of sludge ash as a raw material, contains phosphorus (P), silicon (Si), and iron (Fe), and is characterized by a heavy metal content of 1000 ppm or less.
  • Such a fertilizer for natural water of the present invention can be suitably produced by the method described above.
  • the content of heavy metals in the fertilizer for natural water of the present invention may be 5000 ppm or less, preferably 500 ppm or less, more preferably 100 ppm or less, and further preferably 10 ppm or less. As a result, the effects described above are more significantly exhibited.
  • the concentration of dissolved heavy metal in the fertilizer for natural water of the present invention is preferably 1 ppm or less, more preferably 100 ppb or less. As a result, the effects described above are more significantly exhibited.
  • the content of phosphorus (P) in the fertilizer for natural water of the present invention is not particularly limited, but is preferably 1.0% by mass or more and 20% by mass or less, and 1.5% by mass or more and 9.0% by mass. It is more preferable that the amount is not more than 2.0%, and further preferable that it is not less than 2.0% by mass and not more than 8.0% by mass.
  • the natural water to which the fertilizer for natural water is applied can be eutrophied at a more appropriate concentration and for a longer period of time while more effectively preventing excessive eutrophication.
  • Fertilizer can be provided.
  • the content of silicon (Si) in the fertilizer for natural water of the present invention is not particularly limited, but the content of silicon is preferably 10% by mass or more and 50% by mass or less, and 15% by mass or more and 45% by mass or less. Is more preferable, and 20% by mass or more and 40% by mass or less is further preferable.
  • the natural water to which the fertilizer for natural water is applied can be eutrophied at a more appropriate concentration and for a longer period of time while more effectively preventing excessive eutrophication.
  • Fertilizer can be provided.
  • the content of iron (Fe) in the fertilizer for natural water of the present invention is not particularly limited, but the content of iron is preferably 1.0% by mass or more and 50% by mass or less, and 4.0% by mass or more. It is more preferably 12 mass% or less, and further preferably 5.0 mass% or more and 10 mass% or less.
  • the natural water to which the fertilizer for natural water is applied can be eutrophied at a more appropriate concentration and for a longer period of time while more effectively preventing excessive eutrophication.
  • Fertilizer can be provided.
  • the content of phosphorus in natural water for fertilizer of the present invention X P [wt%], when the content of silicon in natural water for fertilizer of the present invention was X Si [wt%], 1.0 ⁇ X It is preferable to satisfy the relationship of Si /X P ⁇ 50.0, more preferably 3.0 ⁇ X Si /X P ⁇ 30.0, and 4.0 ⁇ X Si /X P ⁇ It is more preferable to satisfy the relationship of 15.0.
  • the content of phosphorus in natural water for fertilizer of the present invention X P [wt%], when the content of iron in natural water for fertilizer of the present invention was X Fe [wt%], 0.9 ⁇ X It is preferable that the relationship of Fe 2 /X P ⁇ 50.0 is satisfied, and it is more preferable that the relationship of 1.0 ⁇ X 2 Fe /X P ⁇ 30.0 is satisfied, and 1.2 ⁇ X Fe 2 /X P ⁇ It is more preferable to satisfy the relationship of 15.0.
  • the sum of the content of Fe and the content of Al in the fertilizer for natural water is X A [mass %], and the sum of the content of alkali metal and the content of Group 2 element in the fertilizer for natural water.
  • X B [mass %] it is preferable that the relationship of 0.01 ⁇ X B /X A ⁇ 20 is satisfied, and it is more preferable that the relationship of 0.1 ⁇ X B /X A ⁇ 10 is satisfied. It is more preferable to satisfy the relationship of 0.5 ⁇ X B /X A ⁇ 3.
  • the fertilizer components can be more suitably eluted over a long period of time, and the effect as a fertilizer for natural water can be more suitably exerted over a long period of time.
  • the fertilizer for natural water may have any shape, but it is preferably granular. This makes it easier to handle fertilizers for natural water.
  • the particle size can be adjusted according to the purpose and environment in which the fertilizer for natural water is used. By changing the particle size of the fertilizer for natural water and the form of administration into natural water, the dissolution period, the balance between immediate effect and sustainability, etc. can be adjusted more suitably.
  • the average particle diameter is preferably 1 ⁇ m or more and 1.0 m or less, and preferably 2 mm or more and 500 mm or less, although it depends on the required duration of the fertilizer for natural water and the like. Is more preferable.
  • the form of administration of the fertilizer for natural water into natural water is not particularly limited as long as it is administered in a state of contacting with natural water, and for example, the fertilizer for natural water is directly put into natural water as it is. It is administered by mixing fertilizer for soil with soil or gravel and laying it on the seabed.
  • the fertilizer for natural water may be applied to natural water in a state of being stored in a container having an opening smaller than the size of the fertilizer for natural water.
  • a bag having a mesh may be used.
  • the constituent material of the bag is not particularly limited, but is preferably a biodegradable material such as iron or polylactic acid.
  • Fertilizers for natural water are, for example, reef blocks, wave-dissipating blocks, artificial fish reefs, levees, and other structures that are installed in contact with natural water, especially large concrete fixed objects or entire structures. Alternatively, it may be used in a state where it is partially included.
  • the fertilizer for natural water may be contained in the entire structure, or may be contained only in a part of the structure (where it can come into contact with natural water).
  • the structure may have the surface thereof coated with a composition containing fertilizer for natural water.
  • the fertilizer for natural water (the structure) may be used by being buried in the ground as long as it can come into contact with natural water.
  • the present invention is preferably applied to a structure already installed at a site that can come into contact with natural water, or a structure that has already been manufactured and has not yet been installed (for example, a structure that is being prepared for installation).
  • a structure that is being prepared for installation is advantageous from the viewpoint of cost and labor.
  • the natural water fertilizer can be extended for a desired period by reattaching the composition containing the fertilizer for natural water.
  • the amount of the fertilizer component when applied to natural water and the growth conditions such as seaweed can be adjusted to adjust the amount of the composition containing the fertilizer for natural water and the composition of the composition, thereby creating a more preferable environment. Can be built up. Further, in the unlikely event that the amount of fertilizer components eluted is excessive, the remaining fertilizer for natural water can be relatively easily recovered.
  • composition containing the fertilizer for natural water can be suitably attached to the structure serving as the base material by, for example, a coating method.
  • the method for producing a fertilizer for natural water of the present invention may have steps (eg, pretreatment step, intermediate treatment step, posttreatment step, etc.) other than the steps described above.
  • it may have a step of easily solubilizing at least a part of constituent components (for example, phosphorus component) of the treated sludge ash.
  • the reactive ionic substance addition step when it has a reducing step together with the reactive ionic substance addition step, it is possible to more suitably enhance the solubility of the phosphorus component or the like contained in the fertilizer for natural water, and iron, silicon.
  • the reactive ionic substance addition step is omitted, that is, at least the first dissolution step, the first solid-liquid separation step, and the reduction step are described.
  • the method including the step of baking and the firing step it is possible to provide a fertilizer for natural water in which the solubilities of fertilizer components, particularly iron components and silicon components, are suitably adjusted.
  • the reducing step includes a step of adding a reducing agent.
  • the solubility of the fertilizer component contained in the fertilizer for natural water can be more suitably increased.
  • the method for producing a fertilizer for natural water of the present invention may have a first dissolution step, a first solid-liquid separation step, a reactive ionic substance addition step, and a firing step, The other steps may not be included.
  • the reactive ionic substance in the second deposition step by using the reactive ionic substance in the second deposition step, a typical case of adding the reactive ionic substance to the first solid in the P component adding step is shown.
  • the reactive ionic substance may be added to the first solid in a form other than this.
  • the method for producing a fertilizer for natural water of the present invention does not have a P component addition step and directly adds a reactive ionic substance to the first solid separated in the first solid-liquid separation step. You may.
  • the method for producing a fertilizer for natural water of the present invention only needs to have a first dissolution step, a first solid-liquid separation step, an ionic substance addition step, and a firing step in this order.
  • the order of the other steps is not limited to that described in the above embodiment, and the order may be changed. For example, you may have a P component addition process after a baking process.
  • the fertilizer for natural water of the present invention is made of sludge ash as a raw material, contains phosphorus, silicon and iron, and the elution rate of heavy metals is 1000 ppm or less, and is not limited to the one produced by the above-mentioned method.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 800° C. (maximum firing temperature): 20° C./min.
  • the temperature is raised in minutes and kept at 800° C. (maximum firing temperature) for 2 hours, then to 200° C. at a temperature decrease rate of 5° C./min, and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min. Thereby, fertilizer for natural water was obtained.
  • Example 5 A fertilizer for natural water was prepared in the same manner as in Example 1 except that the ratio of sodium carbonate (reactive ionic substance) added to 100 parts by mass of the first solid was changed as shown in Table 1. Manufactured.
  • Example 6 To the sample liquid prepared using the first liquid in the same manner as in Example 1, calcium chloride was added so that the ratio of the amount of eluted phosphorus substance to the amount of eluted calcium substance was 1:2, The pH was measured using a pH meter while adding a 1 M NaOH solution, and phosphorus and heavy metals were deposited while stirring (first deposition step). At this time, phosphorus was mainly deposited as a phosphate.
  • the solid-liquid separated filtrate (liquid phase) was measured up.
  • the diluted filtrate was diluted at a specific ratio, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus precipitation rate was calculated from the measurement results.
  • a UV spectrophotometer was used to measure the phosphorus concentration.
  • concentrations of metals and heavy metals in the filtrate were obtained using ICP-AES and ICP-MS, and the amounts of metals and heavy metals contained in the solid phase and the liquid phase were calculated.
  • the solid phase obtained in the second solid-liquid separation step was dried at 105° C. for 2 hours, powdered, and analyzed by XRD.
  • the solid phase After drying the solid phase obtained in the second solid-liquid separation step, the solid phase was put into an Erlenmeyer flask containing 200 mL of 1.0 M NaOH aqueous solution and stirred at 60° C. for 20 minutes. As a result, phosphorus was eluted again (second dissolution step).
  • the second liquid (liquid phase) in which phosphorus was dissolved was subjected to solid-liquid separation with filter paper, and separated from the solid component (solid phase) containing heavy metals (third solid-liquid separation step).
  • the third solid obtained in the fourth solid-liquid separation step was added as a phosphorus-based fertilizer component to the first solid separated in the first solid-liquid separation step at a predetermined ratio (P Component addition step). ..
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 800° C. (maximum firing temperature): 20° C./min.
  • the temperature is raised in minutes and kept at 800° C. (maximum firing temperature) for 2 hours, then to 200° C. at a temperature decrease rate of 5° C./min, and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min.
  • Example 7 A fertilizer for natural water was produced in the same manner as in Example 6 except that the pH at the end of the first precipitation step was changed as shown in Table 1.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • sodium hydroxide as a reactive ionic substance was added at a ratio of 25 parts by mass to 100 parts by mass of the first solid (reactive ionic substance addition step).
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 900° C. (maximum firing temperature) at a temperature raising rate of 20° C./
  • the temperature is raised in minutes and kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C. at a rate of temperature decrease of 5° C./min and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min. Thereby, fertilizer for natural water was obtained.
  • Example 12 A fertilizer for natural water was produced in the same manner as in Example 11 except that the maximum firing temperature was changed to 600°C.
  • Example 13 A fertilizer for natural water was produced in the same manner as in Example 11 except that the maximum firing temperature was changed to 700°C.
  • Example 14 A fertilizer for natural water was produced in the same manner as in Example 11 except that the maximum firing temperature was changed to 800°C.
  • Example 15 A fertilizer for natural water was produced in the same manner as in Example 11 except that the maximum firing temperature was changed to 1000°C.
  • Example 16 A fertilizer for natural water was produced in the same manner as in Example 11 except that the maximum firing temperature was changed to 1100°C.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 900° C. (maximum firing temperature) at a temperature raising rate of 20° C./
  • the temperature is raised in minutes and kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C. at a rate of temperature decrease of 5° C./min and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min. Thereby, fertilizer for natural water was obtained.
  • Example 18 A fertilizer for natural water was produced in the same manner as in Example 17 except that the ratio of calcium carbonate (reactive ionic substance) added to 100 parts by mass of the first solid was changed to 20 parts by mass.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • sodium hydroxide as a reactive ionic substance was added at a ratio of 25 parts by mass to 100 parts by mass of the first solid (reactive ionic substance addition step).
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 900° C. (maximum firing temperature) at a temperature raising rate of 20° C./
  • the temperature is raised in minutes and kept at 900° C. (maximum firing temperature) for 1 hour, then to 200° C. at a temperature lowering rate of 5° C./min, and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min. Thereby, fertilizer for natural water was obtained.
  • Example 20 A fertilizer for natural water was produced in the same manner as in Example 19 except that the holding time at the maximum firing temperature (900°C) in the firing step was changed to 3 hours.
  • Example 21 First, sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%. This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 10 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • sodium hydroxide as a reactive ionic substance was added at a ratio of 20 parts by mass to 100 parts by mass of the first solid (reactive ionic substance addition step).
  • the firing treatment is performed by first heating in a nitrogen atmosphere from room temperature to 200° C. at a heating rate of 10° C./min, holding at 200° C. for 2 hours, and then raising the temperature to 900° C. (maximum firing temperature). : The temperature was raised at 20° C./min, and the temperature was kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C., the temperature was lowered at a rate of 5° C./min, and the temperature was kept at 200° C. for 2 hours. The temperature was decreased to room temperature at a temperature decrease rate of 10° C./min. Thereby, fertilizer for natural water was obtained.
  • the phosphorus content (5% by mass) of the residue was converted into a mole with respect to the amount of the reactive ionic substance added, and the amount of the reactive ionic substance added was also converted into a mole, and the ratio thereof was calculated. showed that.
  • the amount of reducing agent is based on the mass of the residue. The same applies to each of the following examples.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 10 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into moles (mol) per unit mass of the first solid, and the molar ratio of 1 is sufficient as the reactive ionic substance with respect to the moles of phosphorus contained.
  • the firing treatment is performed by first heating in a nitrogen atmosphere from room temperature to 200° C. at a heating rate of 10° C./min, holding at 200° C. for 2 hours, and then raising the temperature to 900° C. (maximum firing temperature). : The temperature was raised at 20° C./min, and the temperature was kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C., the temperature was lowered at a rate of 5° C./min, and the temperature was kept at 200° C. for 2 hours. The temperature was decreased to room temperature at a temperature decrease rate of 10° C./min. Thereby, fertilizer for natural water was obtained.
  • Example 23 A fertilizer for natural water was produced in the same manner as in Example 22 except that the ratio of sodium hydroxide as the reactive ionic substance was changed from 1 to the same amount (1:1).
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 10 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into mol (mol) per unit mass of the first solid, and the reactive ion is added at the same ratio (1:1) to the mol of phosphorus contained.
  • Sodium hydroxide as a volatile substance was added (reactive ionic substance addition step).
  • the firing treatment is performed by first heating in a nitrogen atmosphere from room temperature to 200° C. at a heating rate of 10° C./min, holding at 200° C. for 2 hours, and then raising the temperature to 500° C. (maximum firing temperature). : The temperature was raised at 20° C./min, and the temperature was kept at 500° C. (maximum firing temperature) for 2 hours, then to 200° C., the temperature was lowered at a rate of 5° C./min, and the temperature was kept at 200° C. for 2 hours, then The temperature was decreased to room temperature at a temperature decrease rate of 10° C./min. Thereby, fertilizer for natural water was obtained.
  • Example 25 A fertilizer for natural water was produced in the same manner as in Example 24 except that the maximum firing temperature in the firing step was changed from 500°C to 900°C.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 10 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into mol (mol) per unit mass of the first solid, and the reactive ion is added at the same ratio (1:1) to the mol of phosphorus contained.
  • Sodium hydroxide as a volatile substance was added (reactive ionic substance addition step).
  • the firing treatment is performed by first heating in a nitrogen atmosphere from room temperature to 200° C. at a heating rate of 10° C./min, holding at 200° C. for 2 hours, and then raising the temperature to 900° C. (maximum firing temperature). : The temperature was raised at 20° C./min, and the temperature was kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C., the temperature was lowered at a rate of 5° C./min, and the temperature was kept at 200° C. for 2 hours. The temperature was decreased to room temperature at a temperature decrease rate of 10° C./min. Thereby, fertilizer for natural water was obtained.
  • Example 27 A fertilizer for natural water was produced in the same manner as in Example 26 except that sodium hydroxide was changed to calcium hydroxide as the reactive ionic substance in the step of adding the reactive ionic substance.
  • Example 28 In the step of adding the reactive ionic substance, sodium hydroxide (0.5) and calcium hydroxide (0.5) were combined as the reactive ionic substance to the same amount (1:1) as the molar amount of phosphorus contained. A fertilizer for natural water was produced in the same manner as in Example 26 except for the above.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 20 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into moles (mol) per unit mass of the first solid, and water is added as the reactive ionic substance at a ratio of 5 times the mole of phosphorus contained.
  • Sodium oxide was added (reactive ionic substance addition step).
  • the firing treatment is performed by first heating in a nitrogen atmosphere from room temperature to 200° C. at a heating rate of 10° C./min, holding at 200° C. for 2 hours, and then raising the temperature to 500° C. (maximum firing temperature). : The temperature was raised at 20° C./min, and the temperature was kept at 500° C. (maximum firing temperature) for 2 hours, then to 200° C., the temperature was lowered at a rate of 5° C./min, and the temperature was kept at 200° C. for 2 hours, then The temperature was decreased to room temperature at a temperature decrease rate of 10° C./min. Thereby, fertilizer for natural water was obtained.
  • Example 30 A fertilizer for natural water was produced in the same manner as in Example 29 except that the maximum firing temperature in the firing step was changed to 700°C.
  • Example 31 A fertilizer for natural water was produced in the same manner as in Example 30 except that the maximum firing temperature in the firing step was changed to 900°C.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 20 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into mol (mol) per unit mass of the first solid, and as a reactive ionic substance at a ratio of 0.1 times the mol of phosphorus contained. Was added (reactive ionic substance addition step).
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a temperature raising rate of 10° C./min, held at 200° C. for 2 hours, and then raised to 900° C. (maximum firing temperature) at a temperature raising rate of 20° C./
  • the temperature is raised in minutes and kept at 900° C. (maximum firing temperature) for 2 hours, then to 200° C. at a rate of temperature decrease of 5° C./min and kept at 200° C. for 2 hours, and then to room temperature.
  • Speed The temperature was lowered at 10°C/min. Thereby, fertilizer for natural water was obtained.
  • Example 33 Converting the phosphorus content of the first solid to a mole (mol) per unit mass of the first solid, the sodium hydroxide was added at a ratio of 5 times the mole of phosphorus contained, except that the sodium hydroxide was added.
  • a fertilizer for natural water was produced in the same manner as in Example 32.
  • sludge ash was prepared and dried at 110° C. for 2 hours to make the water content 0%.
  • This sludge ash contained phosphorus, silicon, iron, aluminum, magnesium, and heavy metals.
  • the filter paper was set in the filter to perform solid-liquid separation between the first solid that is a solid phase and the first liquid that is a liquid phase (first solid-liquid separation step). ..
  • the first liquid which was the solid-liquid separated filtrate (liquid phase), was filled up to make a sample liquid.
  • the sample solution was diluted, the phosphorus concentration was measured by the molybdenum blue absorbance method, and the phosphorus dissolution rate was calculated from the measurement results.
  • a UV spectrophotometer was used to analyze the eluate.
  • concentrations of the metal and heavy metal in the sample liquid are obtained using ICP-AES and ICP-MS, and the amount of the metal and heavy metal contained in the solid phase (first solid) and the liquid phase (first liquid) And the amount contained in.
  • carbon black (reducing agent) was added at a ratio of 10 parts by mass to 100 parts by mass of the first solid (reducing agent adding step).
  • the phosphorus content of the first solid is converted into mol (mol) per unit mass of the first solid, and as a reactive ionic substance at a ratio of 0.1 times the mol of phosphorus contained.
  • Calcium hydroxide was added (reactive ionic substance addition step).
  • a firing process was performed (firing process).
  • the temperature was raised from room temperature to 200° C. at a heating rate of 10° C./min in a nitrogen atmosphere, held at 200° C. for 2 hours, and then raised to 900° C. (maximum firing temperature).
  • the temperature is raised at 20° C./min, the temperature is kept at 900° C. (maximum firing temperature) for 2 hours, then the temperature is lowered to 200° C. at a temperature decrease rate of 5° C./min, and the temperature is kept at 200° C. for 2 hours, and then at room temperature. Up to 10° C./min. Thereby, fertilizer for natural water was obtained.
  • Example 35 Changed the ratio of calcium hydroxide (reactive ionic substance) to be added to 10 times the moles of phosphorus contained in the first solid, which was calculated by converting the phosphorus content of the first solid into moles per unit mass.
  • a fertilizer for natural water was produced in the same manner as in Example 34 except for the above.
  • Example 2 A fertilizer for natural water was produced in the same manner as in Example 21 except that the reducing step and the step of adding a reactive ionic substance were omitted.
  • Example 3 A fertilizer for natural water was produced in the same manner as in Example 26 except that sodium carbonate was not used as the reactive ionic substance.
  • the phosphorus content in the first solid separated in the first solid-liquid separation step is 1.0% by mass or more and 10.0% by mass or less.
  • the content of heavy metal in the first solid separated in the first solid-liquid separation step was 3% or less of the initial content.
  • the phosphorus content in the liquid phase separated in the second solid-liquid separation step is 1% by mass or less, and the phosphorus content in the second solid-liquid separation step is
  • the content of heavy metals in the liquid phase thus prepared is 0.1% by mass or less, and the content of phosphorus in the solid phase separated in the third solid-liquid separation step is 95% by mass. %, and the content of heavy metals in the solid phase separated in the third solid-liquid separation step was 90% or more of the initial content, and was separated in the fourth solid-liquid separation step.
  • the content of heavy metals in the solid phase (third solid) was 1.0% or less of the initial content, and the solid phase (third solid) separated in the fourth solid-liquid separation step was used.
  • the phosphorus recovery rate in each case was 50% or more of the initial content rate (the maximum was 85%).
  • the phosphorus content is in the range of 1.0% by mass or more and 10% by mass or less, and the silicon content is 10% by mass or more and 50% by mass or less.
  • the iron content was in the range of 3.0 mass% or more and 50.0 mass% or less, and the heavy metal content was 100 ppm or less.
  • Example The fertilizers for natural water of 1 to 10 all satisfied the relationship of 4.0 ⁇ X Si /X P ⁇ 15 and the relationship of 3 ⁇ X Fe /X P ⁇ 20.0.
  • the fertilizers for natural water of Examples 1 to 10 were analyzed for components by X-ray diffraction (XRD), it was confirmed that all of them contained sodium phosphate.
  • all the fertilizers for natural water obtained in Examples 1 to 10 were granular, and the average particle size thereof was 3 mm or more and 10 mm or less.
  • the fertilizers for natural water obtained in Examples 1 to 10 all had a soluble salt content (alkali metal salt of phosphoric acid compound and/or salt of Group 2 element) of 3.0 mass. % Or more.
  • the content of heavy metals in the fertilizer for natural water of Comparative Example 1 was 1000 ppm or less, and the dissolved concentration was 100 ppb or less.
  • FIG. 4 is a diagram showing the relationship between the number of days elapsed from addition to the aqueous sodium chloride solution and the elution rate of phosphorus components in the fertilizers for natural water according to Examples 1 to 5 and Comparative Example 1.
  • the amount of reactive ionic substances used it is possible to control the elution rate of phosphorus components from fertilizers for natural water, for example, depending on the usage pattern of natural water fertilizers, places of use, etc. It can be said that the balance between immediate effect and sustainability can be adjusted so as to correspond to the characteristics to be achieved.
  • the heating temperature of the heat treatment is changed within the range of 150° C. or higher and 1500° C. or lower, and the treatment time of the heat treatment (heating time at a temperature of 150° C. or higher) is within the range of 1 hour or more and 100 hours or less.
  • the elution amount and precipitation amount of phosphorus were calculated from the results of quantifying the phosphoric acid concentration by the molybdenum blue absorptiometry.
  • the behavior of the metal and heavy metal at the time of elution and precipitation was calculated by ICP spectroscopic analysis (ICP-AES), ICP mass spectrometry (ICP-MS), and elemental analysis equipment.
  • ICP-AES ICP spectroscopic analysis
  • ICP-MS ICP mass spectrometry
  • elemental analysis equipment ICP spectrometry
  • the identification of the precipitate was performed using the X-ray diffraction (XRD) method and the ICP-MS method. The results are summarized in Table 2.
  • FIG. 5 shows the correspondence between the pH of the liquid phase at the end of the first precipitation step and the X-ray diffraction (XRD) pattern of the precipitates of Examples 6, 7 and 8.
  • XRD X-ray diffraction
  • FIG. 6 shows the ratio of the amount contained in (1).
  • the arsenic (As) recovery rate in the third solid is higher than that of other heavy metals, the arsenic content in the third solid is 46.4 mg/kg, which is a standard value for fertilizers. It is significantly lower than 1400 mg/kg, and it is considered that there is no problem in safety.
  • the sample (third solid) 0.15 g
  • the amount of solvent (water) was 12 mL
  • the mixture was stirred at room temperature for 30 minutes, solid-liquid separated, and the dissolved phosphorus concentration was determined by molybdenum blue absorptiometry. And the phosphorus elution rate was calculated.
  • the citric acid solution used here is a solution obtained by dissolving 100 g of citric acid monohydrate in 100 mL of water and diluting the solution 5 times.
  • FIG. 7 shows the results of the water solubility test and the water solubility test for the third solid obtained in the process of producing the fertilizer for natural water of Example 6.
  • FIG. 9 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the dissolution rate of the phosphorus component in the fertilizers for natural water according to Examples 11 to 16.
  • the elution rate of the phosphorus component of the fertilizer for natural water can be changed by changing the firing temperature in the firing process. From this, it is possible to control the elution rate of the phosphorus component from the fertilizer for natural water by the firing temperature in the firing step, for example, the required characteristics depending on the usage form of the fertilizer for natural water, the place of use, etc. It can be said that the balance between immediate effect and sustainability can be adjusted so as to correspond to.
  • FIG. 10 is a graph showing the relationship between the number of days elapsed from addition to the aqueous sodium chloride solution and the elution rate of phosphorus components in the fertilizers for natural water according to Examples 17 and 18.
  • FIG. 11 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the phosphorus component in the fertilizers for natural water according to Examples 19 and 20.
  • the elution rate of the phosphorus component of the fertilizer for natural water can be changed by changing the firing time in the firing process. From this, by the firing time in the firing process, it is possible to control the elution rate of phosphorus components from the fertilizer for natural water, for example, the required characteristics, depending on the use form, place of use, etc. of the fertilizer for natural water. It can be said that the balance between immediate effect and sustainability can be adjusted so as to correspond to.
  • FIG. 12 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the iron component in the fertilizers for natural water according to Example 21 and Comparative Example 2.
  • the elution rate of the iron component is significantly improved by performing the reducing step using the reducing agent together with the reactive ionic substance adding step. From this, it can be said that the iron component contained in the sludge ash as a raw material is changed into a highly soluble state by the reduction process.
  • FIG. 13 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the iron component in the fertilizers for natural water according to Examples 22 and 23.
  • the elution rate of the iron component from the fertilizer for natural water finally changes depending on the amount of the reducing agent used in the reduction process. From this, the amount of reducing agent used, it is possible to control the elution rate of the iron component from the fertilizer for natural water, for example, depending on the usage pattern of the fertilizer for natural water, the place of use, etc. It can be said that the balance between immediate effect and sustainability can be adjusted accordingly.
  • FIG. 14 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the iron component in the fertilizers for natural water according to Examples 24 and 25.
  • the elution rate of the iron component from the fertilizer for natural water finally changes depending on the firing temperature in the firing process. From this, it is possible to control the elution rate of the iron component from the fertilizer for natural water by the firing temperature. For example, in order to respond to the required characteristics according to the usage form, place of use, etc. of the fertilizer for natural water. Moreover, it can be said that the balance between immediate effect and sustainability can be adjusted.
  • FIG. 15 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the silicon component in the fertilizers for natural water according to Examples 26 to 28 and Comparative Example 3.
  • the amount of reactive ionic substances used it is possible to control the elution rate of silicon components from fertilizers for natural water, for example, depending on the usage pattern of fertilizers for natural water, place of use, etc. It can be said that the balance between immediate effect and sustainability can be adjusted so as to correspond to the characteristics to be achieved.
  • FIG. 16 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the silicon component in the fertilizers for natural water according to Examples 29 to 31.
  • the elution rate of the silicon component from the fertilizer for natural water finally changes depending on the firing temperature in the firing process. From this, it is possible to control the elution rate of the silicon component from the fertilizer for natural water depending on the firing temperature. For example, according to the usage form of the fertilizer for natural water, the place of use, etc. Moreover, it can be said that the balance between immediate effect and sustainability can be adjusted.
  • FIG. 17 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the silicon component in the fertilizers for natural water according to Examples 32 and 33.
  • the elution rate of the silicon component of the fertilizer for natural water can be changed by changing the concentration of the reactive ionic substance. From this, the amount of reactive ionic substances used, it is possible to control the elution rate of silicon components from fertilizers for natural water, for example, depending on the usage pattern of fertilizers for natural water, place of use, etc. It can be said that the balance between immediate effect and sustainability can be adjusted so as to correspond to the characteristics to be achieved.
  • FIG. 18 is a diagram showing the relationship between the number of days elapsed from the addition to the aqueous sodium chloride solution and the elution rate of the silicon component in the fertilizers for natural water according to Examples 34 and 35.
  • a sludge ash and an acidic liquid are mixed to dissolve a heavy metal and phosphorus contained in the sludge ash, and the heavy metal and phosphorus are dissolved.
  • a first solid-liquid separation step of separating and removing the first liquid from the first solid; and a hydroxide and/or salt of an alkali metal and/or a Group 2 element with respect to the first solid.
  • the method includes a reactive ionic substance addition step of adding a reactive ionic substance, and a firing step of subjecting the composition containing the first solid and the reactive ionic substance to a firing treatment.
  • the fertilizer for natural water of the present invention is made of sludge ash as a raw material, contains phosphorus, silicon and iron, and has a heavy metal content of 1000 ppm or less. Therefore, while effectively utilizing sludge ash, to provide a fertilizer for natural water, which contains phosphorus, silicon and iron, and has a sufficiently low content of heavy metals, and a method for producing the fertilizer for natural water. be able to.

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Abstract

Ce procédé de fabrication d'un engrais pour l'eau naturelle est caractérisé en ce qu'il comprend : une première étape de dissolution consistant à mélanger la cendre de boues avec un liquide acide pour dissoudre les métaux lourds et le phosphore contenus dans la cendre de boues; une première étape de séparation solide-liquide consistant à séparer et à éliminer d'un premier solide un premier liquide dans lequel les métaux lourds et le phosphore sont dissous; une étape d'ajout de substance ionique réactive consistant à ajouter, au premier solide, une substance ionique réactive qui est un métal alcalin et/ou un hydroxyde de Groupe II et/ou un sel; et une étape de cuisson consistant à soumettre une composition comprenant le premier solide et la substance ionique réactive à la cuisson. La présente invention permet de produire un engrais pour eau naturelle qui utilise efficacement de la cendre de boues et comprend du phosphore, du silicium et du fer et a une teneur suffisamment faible en métaux lourds; et de mettre en oeuvre le procédé de fabrication de l'engrais pour l'eau naturelle. En particulier, la présente invention permet de produire un engrais pour l'eau naturelle pour lequel la vitesse de dissolution d'un composant d'engrais est contrôlée de manière appropriée et de réaliser le procédé de fabrication de l'engrais pour l'eau naturelle.
PCT/JP2019/048290 2018-12-11 2019-12-10 Procédé de fabrication d'engrais pour eau naturelle, et engrais pour eau naturelle WO2020122068A1 (fr)

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JP2010132465A (ja) * 2008-12-02 2010-06-17 Hiroshima Univ 有機物焼却灰からのリン回収方法及び肥料の製造方法

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EP2725001B1 (fr) 2011-06-27 2019-10-02 Taiheiyo Cement Corporation Engrais phosphaté, et son procédé de production

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JP2001130903A (ja) * 1999-08-23 2001-05-15 Nkk Plant Engineering Corp リン酸塩回収方法
JP2007246360A (ja) * 2006-03-17 2007-09-27 Ngk Insulators Ltd 下水汚泥焼却灰を原料とする肥料の製造方法
JP2010132465A (ja) * 2008-12-02 2010-06-17 Hiroshima Univ 有機物焼却灰からのリン回収方法及び肥料の製造方法

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