JP2012171856A - Fertilizer production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fertilizer production method which uses shellfishes or the like being waste materials as raw materials of the fertilizer to recycle them, and by which the generation of bad odors in the production process is reduced.SOLUTION: The fertilizer production method includes: a pulverizing step ST3 of pulverizing a raw material containing, as main components, shellfishes; a mixing step ST4 of mixing the raw material pulverized in the pulverizing step ST3 with wood waste; and a fermenting step ST5 of fermenting the mixed raw material and wood waste mixed in the mixing step ST4 for one month or more. In the mixing step, the mixing ratio of the raw material and the wood waste is 2:1.

Description

  The present invention relates to a fertilizer manufacturing method using waste including shellfish.

  2. Description of the Related Art Conventionally, in a thermal power plant or a nuclear power plant, power is generated by transmitting steam from the boiler to water to generate steam, and sending the steam to the turbine to rotate the turbine. And the water vapor | steam sent in to the turbine is cooled with cooling water, is condensed, and is supplied again to a boiler.

  Seawater is used as cooling water for condensing water vapor, and seawater is taken in from the intake through operation of the intake facility and supplied to the power generation facility. And the seawater heat-exchanged in the power generation facility is discharged into the sea.

  Seawater taken from the intake through the operation of the intake facility includes shellfish (red barnacles, mussels, etc.), seaweeds, small fish (hereinafter referred to as shellfish, etc.). Supplies seawater to power generation facilities after removing shellfish and the like from seawater. At this time, shellfishes removed from seawater must be incinerated at administrative treatment facilities (for example, garbage disposal sites) as business-related general waste based on the Waste Disposal and Cleaning Act (Waste Disposal Law), etc. is there.

  Conventionally, it has been proposed to use shell incineration ash obtained by incineration of shellfish adhering to piping for cooling seawater in a power plant as an essential component of raw materials for fermented sludge fertilizer (Patent Document 1).

JP 2003-055081 A

However, salinity contained in shellfish may cause an increase in dioxin concentration during the combustion process, so it is necessary to satisfy the acceptance standards (reduction in salinity) of administrative treatment facilities. Conventionally, in order to satisfy the acceptance standard of processing facilities, the following measures are taken.
1. Drain the shellfish that have been landed [1 week].
2. Wash shellfish with water (remove salt). All washing water is collected and treated as industrial waste sludge.
3. Shellfish, etc. are enclosed in a sandbag and drained and sun-dried [about 1 to 2 weeks].
4). Carry out shellfish etc. based on acceptance criteria for processing facilities [80 bags / week].

However, the above countermeasures have the following problems.
First, shellfish and the like are recyclable waste, and incineration of such waste is not in line with the “Basic Law for Promoting Recycling-oriented Society”. Furthermore, incineration of wastes such as shellfish generates other wastes such as sludge. In addition, hazardous substances (such as dioxins) may be generated during the incineration of waste (such as shellfish).

  Moreover, shellfish etc. may rot in the process of draining and may cause a bad odor. Moreover, since it is necessary to take the above measures before incineration, waste disposal costs increase.

  The present invention provides a fertilizer manufacturing method that solves such problems and performs recycling by using shellfish or the like as a raw material for fertilizer, and that reduces the generation of malodor in the fertilizer manufacturing process. For the purpose.

  In order to achieve the above object, the present invention has the following configuration.

  (1) A pulverization step of pulverizing raw materials mainly composed of shellfish, a mixing step of mixing wood chips with the raw materials pulverized in the pulverization step, and the raw materials and wood chips mixed in the mixing step for one month or more The fertilizer manufacturing method characterized by having a fermentation process to ferment and making the mixing ratio of the said raw material and wood waste in the said mixing process into 2: 1.

  According to (1), although the raw material satisfies the soil environmental standard value, the main component is shellfish, so that a bad odor may be generated. Thus, by mixing the pulverized raw material and wood waste so that the mixing ratio of the raw material and wood waste is 2: 1, the generation of malodor can be reduced by the deodorizing action of the wood waste. Moreover, it becomes possible to manufacture the fertilizer which removed the malodor by fermenting the mixture of a raw material and wood waste for one month or more. In addition, waste (shellfish) that has been disposed of by incineration can be recycled as fertilizer. As a result, harmful substances generated by incineration can be reduced, and soil can be used as environmentally friendly fertilizer. It becomes possible to return.

  (2) The fertilizer manufacturing method according to (1), wherein the wood chips have a length of 35 mm or less.

  According to (2), when the fertilizer manufactured by mixing wood chips having a length of 35 mm or less is sprayed on the soil, the wood chips do not stand out.

  (3) The fertilizer manufacturing method according to (1) or (2), wherein the raw material is waste removed from seawater in a water intake facility that takes in seawater to be supplied to a power generation facility.

  According to (3), shellfish, seaweed, small fish, etc. that have been landed at the water intake facility of the power plant can be regenerated as fertilizer rather than incinerated.

  (4) The fertilizer manufacturing method according to any one of (1) to (3), wherein 80% or more of the raw materials are shellfish.

  According to (4), since the shell part of shellfish becomes a lime component and the contents of shellfish become an organic component, it becomes possible to manufacture the fertilizer suitable for a plant.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the fertilizer manufacturing method which implement | achieved recycling by using the shellfish etc. which are wastes as a raw material of fertilizer, and implement | achieving generation | occurrence | production of malodor in a manufacture process.

It is explanatory drawing which shows the path | route of the intake channel which supplies seawater to a power generation facility. It is process drawing which shows the manufacturing process by the fertilizer manufacturing method in one Embodiment of this invention. It is a figure which shows the chemical analysis result of the mixing target object mixed with a raw material. It is a figure which shows the evaluation result of the mixing target object mixed with a raw material. It is a figure which shows the chemical analysis result of the mixture of a raw material and wood waste. It is a figure which shows the example of arrangement | positioning of the mixing target object and wood waste in a fermentation process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Disposition of water intake path and dust remover]
FIG. 1 is an explanatory diagram showing a route of an intake channel that supplies seawater to a power generation facility. An intake channel 10 is provided in the sea, and seawater introduced by the intake channel 10 is supplied to the power generation facility 50 and used for cooling steam supplied to a turbine that rotates the generator. In addition, a dust remover 12 is provided in the intake channel 10. The dust remover 12 is disposed near the coast.

  The dust remover 12 removes so as to scoop up contaminants in seawater by rotating a plurality of car members (not shown) like a water wheel. The cage member is formed of a net-like member, and separates contaminants having a predetermined size or more from the seawater flowing through the intake channel 10 to land. As contaminants, there are many shellfish, small fish, and seaweed, and depending on the season, jellyfish may be landed.

  The fertilizer manufacturing method of the present embodiment is to manufacture fertilizer using shellfish, small fish, seaweed and the like landed by the dust remover 12 as raw materials.

[Manufacturing process of fertilizer]
FIG. 2 is a process diagram showing a production process according to a fertilizer production method in one embodiment of the present invention. As shown in FIG. 2, the fertilizer manufacturing method in the present embodiment includes a landing process ST1 for landing shellfish and the like as raw materials, a storage process ST2 for temporarily storing the landed raw materials, and pulverization for pulverizing the landed raw materials. It comprises a process ST3, a mixing process ST4 for mixing wood chips into the pulverized raw material, and a fermentation process ST5 for fermenting the mixture of the raw material and wood chips in a bag.

  In the landing process ST1, contaminants as raw materials for fertilizer are landed from the sea by the dust remover 12 (see FIG. 1) and loaded in a predetermined area of the water intake facility. More than 80% of the contaminants landed by the dust remover 12 (see FIG. 1) are shellfish (red barnacles, mussels and others), and seaweeds, small fish, and the like are also included.

  The landed contaminants are placed on a conveyor, transported to a storage, and packed in a flexible container bag at the storage. In the case where inorganic contaminants such as metal, glass, and plastic are mixed in the contaminants, the inorganic contaminants are removed while the contaminants are being conveyed by the conveyor.

  In the storage process ST2, the raw materials are temporarily stored in a storage place for 1-2 months in a state of being packed in a flexible container bag. Here, the raw material packed in the flexible container bag remains salted because it has not been washed after being landed. Shellfish are also packed in flexible containers with the contents filled.

  In the pulverization step ST3, the raw materials packed in the flexible container bag are put into a pulverizer and granulated. In addition to the calcium component of shells, the raw materials that have become granular contain shellfish and organic components such as seaweeds and small fish.

  In the mixing step ST4, wood chips are added to the pulverized raw material and mixed. As the wood waste, wood waste and sawdust can be applied, and wood waste having a length of about 25 to 35 mm is particularly preferable. Moreover, as a kind of tree, hardwood, cypress, and cedar wood scraps are applicable. The mixing ratio of the raw material and wood waste will be described later in detail. As a result of the experiment, when the mixing ratio of the raw material and wood waste is 2: 1 (the wood waste content is about 33%). Good results were obtained.

  In the fermentation step ST5, the mixture of raw materials and wood waste is accumulated in a predetermined fermentation place and fermented for one month or longer. The fermentation period is adjusted appropriately according to the season. And after the fermentation period of one month or more passes, the fertilizer which consists of a mixture of a raw material and wood waste is completed.

  By the way, using only raw materials mainly consisting of shellfish, component analysis of the fertilizer manufactured through the storage step ST2, the pulverization step ST3 and the fermentation step ST5 described above, and the soil environmental standards defined by the Environmental Standards Act I evaluated whether it met. As a result, it turned out that the fertilizer manufactured only from the raw material which has a shellfish as a main component satisfy | fills the soil environmental standard. However, since malodor is generated during the manufacturing process, it is necessary to suppress this malodor.

  Therefore, in order to suppress malodor, wood waste is added to the raw material mainly composed of shellfish in the mixing step ST4. However, if the finished fertilizer does not meet the soil environmental standards, it cannot be used as a fertilizer. For this reason, it is necessary to perform chemical component analysis on the wood waste mixed with the raw material to determine whether or not it can be mixed with the raw material.

[Selection of candidate for mixed object]
Here, for reference, three types of bark compost samples made from fertilized waste wood waste were extracted and evaluated to meet soil environmental standards. As a result, it was found that the value of at least one of arsenic and boron contained in the soil environment standard item was exceeded.

  After examining the cause, bark compost is made by finely cutting the bark removed from the surface of the wood during wood processing and fermenting it by adding fermentation-promoting materials such as chicken manure and sewage sludge. is there. The addition of this fermentation promoting material is presumed to be the cause of excess arsenic or boron values. For this reason, it decided to select the wood waste which does not contain the fermentation promotion material as the wood waste mixed in mixing process ST4.

  Next, we selected three types of wood waste that do not contain fermentation-promoting materials as materials having deodorizing properties, and evaluated whether they are suitable as fertilizers.

  First, as a candidate for the mixing object to be mixed with the raw material, three types of wood waste, that is, wood waste having a length of 60 mm to 70 mm (hereinafter referred to as the mixture A) serving as a raw material for bark compost, soil to prevent the propagation of weeds Wood chips (hereinafter referred to as “mixture B”) and sawdust (hereinafter referred to as “mixture C”) having a length of 25 mm to 35 mm, which are laid on the substrate, are each subjected to chemical analysis, and arsenic, which is a candidate for these mixed objects. I examined the values of fluorine and boron. For reference, we also examined dam soil.

  As a result, as shown in FIG. 3 (a), the mixture C and dam soil satisfy the arsenic, fluorine and boron items in the soil environment standard, but the mixture A is boron and the mixture B is arsenic. It was found that exceeded the regulation value.

  For this reason, when selecting the mixture C or dam soil as a mixture, it is possible to arbitrarily set the mixing ratio of the mixture C or dam soil and raw materials. In addition, when selecting the mixture A or the mixture B as a mixture, when the mixture A or the mixture B is mixed with the raw materials, the mixture should be such that the boron or arsenic value does not exceed the regulation value of the soil environment standard. It is necessary to set the mixing ratio between A or the mixture B and the raw material.

  Next, a chemical analysis is performed on the mixture of the raw material and the mixture B so that the content of the mixture B is 33% (raw material: mixture B = 2: 1), and the values of arsenic, fluorine, and boron are examined. I tried. Also, as a reference, the chemical analysis of the material mixed with dam soil is conducted so that the content of dam soil is 50% (raw material: dam soil = 1: 1), and the values of arsenic, fluorine and boron are examined. I tried.

  As a result, as shown in FIG. 3B, when the content of the mixture B is 33% and the content of the dam soil is 50%, all are items of arsenic, fluorine and boron in the soil environment standard. It was found that Therefore, it was found that when the content of the mixture B is 33% or less, the arsenic, fluorine, and boron items in the soil environment standard are satisfied.

  Figure 4 shows the appearance survey, simple chemical analysis, malodor survey, mixed chemical analysis, and cost survey for the three types of wood chips and dam soil of the mixture A to C listed as candidates for the mixing target to be mixed with the raw materials. The result of evaluating whether each is suitable is shown.

  Appearance survey is to investigate the appearance of the created fertilizer, and the results of the survey are no problem for the mixture B, C, dam soil, but the mixture A has a large piece of wood itself and is to be applied as fertilizer Evaluated that it did not look good.

  Single chemical analysis examines the values of arsenic, fluorine and boron in soil environmental standards. As shown in FIG. 3 (a), the analysis results showed that the mixture A and B exceeded the regulation value, but the mixture C and dam soil were evaluated to satisfy the regulation value.

  As a result of the malodor investigation, the mixtures A, B, and C have a raw odor for about one week after mixing with raw materials. However, since then, the bad odor was eliminated, so it was evaluated that there was no problem. Some raw odor remained for the dam soil.

  As a result of the mixed chemical analysis, it was evaluated that the mixture C and the dam soil satisfied the regulation value. Moreover, about the mixture B, as shown in FIG.3 (b), it evaluated that the regulation value was satisfied. In addition, about the mixture A, the chemical analysis is not performed.

  Regarding the cost, the mixtures A and B and the dam soil can be obtained at a low cost, but the mixture C is expensive.

  As a result of comprehensive evaluation based on the above evaluation, the fertilizer manufactured by mixing the raw material and the mixture B so that the mixture B is optimal as a mixing target and the content ratio of the mixture B is 33%, The best evaluation was obtained. In addition, dam soil is also suitable as an object to be mixed, and the fertilizer manufactured by mixing raw materials and dam soil so that the content of dam soil is 50% was generally evaluated well. Moreover, about the mixture C, since it was expensive, it evaluated that it was not suitable as a mixing target object. Moreover, about the mixture A, it evaluated that it was not suitable as a mixing target object for the reason that the wood chip itself is large and it does not look good to disperse as fertilizer. Therefore, in this embodiment, it decided to ferment and fertilize what mixed the raw material and the mixture B so that the content rate of the mixture B might be 33%.

  In addition, when the mixture C (sawdust) becomes available at a low cost, it can be used as an object to be mixed with raw materials. Moreover, about the mixture A (wood waste used as the raw material of bark compost), for example, after mixing with raw materials, the fermentation period is lengthened, and after the mixture A is easily broken, it is pulverized through a pulverizer and necessary. It becomes possible to use as a fertilizer by setting a fermentation period further according to the above.

[Evaluation of manufactured fertilizer]
Next, the chemical analysis of the fertilizer manufactured by mixing the raw material and the mixture B so that the content rate of the mixture B is 33% is performed, and the items defined in the soil environment standard and the analysis values of the fertilizer components are illustrated. I summarized it in 5.

  As shown in FIG. 5, it was found that the fertilizer manufactured by mixing the raw material and the mixture B so that the content ratio of the mixture B was 33% satisfied all the items defined in the soil environmental standards. . Moreover, it turned out that nitrogen, phosphoric acid, and potassium are contained as a fertilizer component.

  Therefore, the fertilizer manufactured by mixing the raw material and the mixture B so that the content of the mixture B is 33% can be applied to the soil, and can be used as a fertilizer useful for plant growth. is there.

  Further, in order to suppress the generation of malodor, it is effective to increase the content of wood waste, but in order to make as much fertilizer as possible the raw material that is waste, it is necessary to increase the content of the raw material. For this reason, it is desirable to set the mixing ratio of the raw material and the wood waste so that the malodor is eliminated at the end of the fermentation period. According to the present embodiment, by setting the mixing ratio of the raw material and wood waste to 2: 1, it is possible to suppress the generation of malodor and make the raw material as fertilizer as much as possible.

  Moreover, as shown in FIG. 4, since the raw odor is eliminated after about one week after mixing the raw material and wood waste, fermentation can be achieved even if the wood waste content is set slightly low (for example, 30%). It can be estimated that the raw odor can be eliminated within about one month, which is the period. Further, as shown in FIG. 3, the content of arsenic in the mixture B alone was 0.014, but it was reduced to 0.007 by mixing the raw material and wood waste at a mixing ratio of 2: 1. . Here, since the regulation value of arsenic in the soil environment standard is 0.01, it can be estimated that the soil environment standard value is satisfied even if the wood scrap content rate is set slightly high (for example, 35%). is there. Therefore, according to the present embodiment, the mixing ratio of the raw material and the wood waste is set to 2: 1. However, it is not necessary to mix the raw material and the wood waste exactly 2: 1. That's fine. For example, the wood scrap content is about 30% to 35%, in other words, the raw material content is about 65% to 70%.

  As described above, according to the present embodiment, although the pulverized raw material satisfies the soil environment standard value, the main component is shellfish, and therefore, a bad odor may be generated. Therefore, by mixing the pulverized raw material and wood waste so that the mixing ratio of the raw material and wood waste is 2: 1, the generation of malodor can be reduced by the deodorizing action of the wood waste. Moreover, it becomes possible to manufacture the fertilizer which removed the malodor by fermenting the mixture of a raw material and wood waste for one month or more. Moreover, by recycling waste that has been incinerated conventionally as fertilizer, it is possible to reduce harmful substances generated by incineration and return it to the soil as environmentally friendly fertilizer.

  Moreover, according to this embodiment, the fertilizer manufactured by mixing wood chips having a length of 35 mm or less does not stand out when it is applied to the soil.

  Moreover, according to this embodiment, shellfish, seaweed, small fish, etc. that have been landed at the water intake facility of the power plant can be regenerated as fertilizer instead of being incinerated.

  Moreover, according to this embodiment, the lime component of the shell part of shellfish and the contents of shellfish become an organic component, and it becomes possible to manufacture the fertilizer suitable for a plant.

  Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment. For example, in the fermentation step ST5, for example, when mixing raw materials and wood waste, 2/3 of the prepared wood waste is mixed with the raw materials. When the mixture of the raw material and wood waste is accumulated in the fermentation place, as shown in FIG. 6, the remaining 1/3 wood waste is placed on the top and bottom or the periphery of the mixture. Then, after about one week, the wood waste spread around the mixture is mixed. Thus, by performing a fermentation process, generation | occurrence | production of malodor can be suppressed further.

  In addition, by making the fermentation place in a place where there is a pipe for draining the seawater heated and exchanged in the power generation facility, and adding the temperature of the warmed seawater to the fertilizer at the fermentation place, You may encourage fermentation.

10 Intake Channel 12 Dust Remover 50 Power Generation Facility ST1 Landing Process ST2 Storage Process ST3 Grinding Process ST4 Mixing Process ST5 Fermentation Process

Claims (4)

A crushing process for crushing raw materials mainly composed of shellfish,
A mixing step of mixing wood chips with the raw material crushed in the pulverization step;
A fermentation process in which the raw materials and wood waste mixed in the mixing process are fermented for one month or more;
The fertilizer manufacturing method characterized by making the mixing ratio of the said raw material and wood waste into 2: 1 in the said mixing process.   The fertilizer manufacturing method according to claim 1, wherein the wood chips have a length of 35 mm or less.   The fertilizer manufacturing method according to claim 1, wherein the raw material is waste removed from seawater in a water intake facility that takes in seawater supplied to a power generation facility.   The fertilizer manufacturing method according to any one of claims 1 to 3, wherein 80% or more of the raw materials are shellfish.

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