JP2012110795A - Method of recycling bivalve as resource - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of recycling bivalves as resources, while reducing the cost for treating a large amount collected bivalves.SOLUTION: The method of recycling bivalves as resources includes: a step S3 (a deodorizing step) of mixing saw dust or wood chips with bivalves to obtain a deodorizing effect, a step S4 (a fermentation step) of keeping a large amount of bivalves containing saw dust or wood chips in a shape of a mound to decay/decompose organic matter therein, a step S5 (a washing step) of washing a large amount of bivalves containing saw dust or wood chips to remove foreign matter other than shells, and a step S8 (a heat-treating step) of treating the shells with heat, thereby reducing the cost for treating a large amount collected bivalves and recycling the bivalves as resources for use in poultry farming feed.

Description

  The present invention relates to a bivalve recycling method for processing a large amount of discharged bivalves into only shells and recycling them.

  It is necessary to remove and dispose of bivalves, especially mussels attached to antifouling membranes and structures, for offshore civil works and maintenance of drainage outlets at seaside factories. These recovered large clams contain organic matter and moisture, and the general waste treatment plant cannot process large quantities of bivalves, so traditionally, “animal residues” or “ The sludge was incinerated or landfilled. However, this processing method is expensive, and it is necessary to consider another processing method.

  Patent Document 1 discloses a filtration method using a material mainly composed of organic matter such as rice husk, sawdust, and beer lees after solution treatment of scallop shells, or scallop shell powder as a main component. A method of using scallop uro that is used as a fertilizer, feed, and feed is obtained by solid-liquid separation using a filtration method using the material configured as a filter material, and mixing the scallop uro that has been separated from the solution with the filter material. Yes.

JP-A-10-286068

  However, it is not limited to the scallop shell as in the invention according to Patent Document 1, and the establishment of a recycling method for bivalve in general is required.

  The present invention has been made in view of the above points, and has an object to provide a method for recycling a bivalve to reduce the processing cost of a large amount of bivalve recovered and to recycle the bivalve. To do.

As a means for solving the above problems, the present invention is a method for processing and recycling a large amount of discharged bivalves, wherein the large amount of bivalves includes sawdust and wood. A deodorizing step that mixes chips to obtain a deodorizing effect, a fermentation step that decays and decomposes organic matter by leaving a large amount of bivalve shells containing sawdust and wood chips on a bank, and a large amount of bivalve shells containing sawdust and wood chips And a cleaning step for removing foreign substances other than shells and a heat treatment step for heat-treating the shells.
In the invention of claim 1, first, in the deodorization step, the deodorization effect can be obtained by mixing 40% or more of sawdust and wood chips with respect to the bivalve capacity. Next, in the fermentation step, fermentation can be promoted by embedding a large amount of bivalves including sawdust and wood chips. Next, in the cleaning step, a large amount of bivalves containing sawdust and wood chips are placed in a wire mesh jar and classified in the air, and then the wire mesh jar is placed in the wash water and the organic matter in the sawdust, wood chips and bivalves. To leave only the shells. Next, in the heat treatment step, the shell is heated at a predetermined temperature to remove organic matter remaining in the shell and sterilize.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, after the washing step, a drying step of drying the shell by sun drying is provided.
In invention of Claim 2, the water | moisture content contained in a shell is evaporated by a drying step. In addition, it is better to set the drying period so that the moisture contained in the shell becomes 5% or less.

The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, in the fermentation step, a large amount of bivalves including embankment-like sawdust and wood chips are stirred at regular intervals. It is.
In the invention of claim 3, the fermentation period can be shortened by promoting the fermentation.

The invention described in claim 4 is characterized in that, in the invention described in any one of claims 1 to 3, the shell is heat-treated at about 100 ° C. in the heat treatment step.
In the invention of claim 4, in the heat treatment step, the shell is heat-treated at about 100 ° C., so that the organic matter adhering to the shell can be removed and sterilized while suppressing the carbonization of the shell.

The invention described in claim 5 is characterized in that, in the invention described in any one of claims 1 to 4, after the heat treatment step, a particle size adjusting step of pulverizing the shell to a predetermined particle size or less is provided. .
In the invention of claim 5, in the particle size adjustment step, a large amount of shells are pulverized to a predetermined particle size or less, so that it is optimal as a poultry feed.

  According to the bivalve recycling method of the present invention, it is possible to greatly reduce the processing cost of the bivalve discharged in large quantities, and it can be recycled as poultry feed, which is environmentally friendly and effective.

FIG. 1 is a flow showing a bivalve recycling method according to an embodiment of the present invention. FIG. 2 is an analysis result of harmful substances in feed obtained by the bivalve recycling method according to the embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS. 1 and 2.
For example, a large amount of bivalves, for example, mussels, are discharged for offshore civil engineering and maintenance of drain outlets at the seaside factory. The discharged large amount of blue mussels are transported from the discharge location to the treatment facility in a state of being housed in a watertight container.

In the treatment facility, as shown in FIG. 1, first, in step S1, it is determined whether or not a considerable amount of organisms such as fish and starfish are mixed with the mussel capacity, and it is determined that it is not mixed. If it has been determined, the process proceeds to step S2, and if it is determined that it is mixed, it is incinerated because it is incompatible as feed conversion.
Next, in step S2, it is determined whether or not the mixing rate of earth and sand into a large amount of mussels is 50% or less. Returned to In addition, the earth and sand discharged | emitted by the classification process of step S50 is sludge-treated. Further, when it is determined in step S2 that the mixing rate of earth and sand into a large amount of mussels is 50% or less, the process proceeds to step S3. Note that step S3 is performed when there is a concern that a large amount of mussel odor will occur.

Next, in step S3, a large amount of blue mussels are mixed with sawdust and wood chips to obtain a deodorizing effect (deodorizing step). At that time, from the standpoint of deodorization alone, it is better to mix more than 40% of sawdust and wood chips with respect to the capacity of mussels. On the other hand, it is preferable to mix 40% to 60% of sawdust and wood chips. In order to obtain a deodorizing effect, only a large amount of blue mussel may be mixed with sawdust, only wood chips may be mixed, or a mixture of sawdust and wood chips may be mixed.
Therefore, the deodorization verification of wood chips was conducted against green mussels, although the target of bivalves is different. As a result, when mixing wood chips in an amount of approximately 50% with respect to the capacity of green mussel, the off-flavor is reduced to approximately 50%, and when mixing wood chips with an amount of approximately 95% with respect to the capacity of green mussel. It was found that the off-flavor was reduced to about 20%.

Next, in step S4, a large amount of blue mussel mixed with sawdust and wood chips is filled with an embankment (for example, bottom width: 4 m, bottom length: 3.5 to 10 m, height: 1.5). To 1.8 m) (fermentation step). This is because the internal temperature of the mussel is increased by leaving it in the form of embankment, and the organic matter in the mussel is rotted, decomposed, and fermented. In addition, when ambient temperature is 25 degreeC-35 degreeC, the embankment-like internal temperature is rising to 40 degreeC-75 degreeC. Moreover, the leaving period is appropriately set according to the capacity, season, climate, etc. of the mussel containing sawdust and wood chips. In this embodiment, the total capacity of blue mussels containing sawdust and wood chips is about 20 m ³ , and the season was summer, so it was left for about 3 days. During the standing period, it is better to stir mussel containing embankment-like sawdust and wood chips about once a day. Thereby, fermentation can be promoted. In addition, in this step S4, what is not fully fermented, such as a shellfish not opening, will be compost disposal.

Next, in step S5, a large amount of bivalves including sawdust and wood chips are washed to remove foreign substances other than the shells (washing step). Specifically, first, a large amount of bivalves (for example, about 0.8 m ³ ) containing sawdust and wood chips are made into a wire netting cage (for example, length: 1.2 m, width: 1.2 m, height: 1.2 m). ) And classify in air. Subsequently, the wire mesh jar containing the bivalves is placed in washing water and washed so as to be shaken. As a result, only the shell remains in the wire mesh cage, and the contents of the shell, sawdust, wood chips, and small garbage are removed. In addition, agricultural water is used as the washing water, and since the agricultural water contains microorganisms, the agricultural water is resistant to decay and can be used repeatedly. In this embodiment, agricultural water is used as the washing water. However, when the agricultural water is used in a place where agricultural water is not available, clean water is used. Drain or dispose of. It should be noted that sawdust, wood chips, earth and sand, and nutrients fermented by this step S5 are composted.

Next, in step S6, the shell washed in step S5 is dried by sun drying (drying step). The drying period is set in consideration of the temperature, but the degree of drying is based on a moisture content of 5% or less. In addition, in this step S6, what remains a lot after drying is composted.
At the time of completion of this step S6, the loss on ignition (amount of organic matter containing volatile substances) of the bivalve (shell) has reached less than 5%, and from this also during the above steps S4 to S6 It is thought that most of organic substances and moisture were removed. Further, in the ignition loss, when the sample is heated at 600 ° C., calcium carbonate, which is a component of the shellfish, volatilizes. Therefore, when attention is paid only to the organic matter, the residual amount becomes very small.

  By the way, when it is determined that there is no off-flavor in the large amount of mussels after Step S2 described above and organic matter remains in the mussels, the process proceeds to Step S4. If it is determined that no organic matter remains in the blue mussel, the process proceeds to step S5. Further, after step S2, if it is determined that a large amount of blue mussels have no off-flavor, no organic matter remains in the blue mussels, and no soil or sand is mixed, the process proceeds to step S6.

Next, in step S7, the shell is stored in a warehouse or the like until it reaches a predetermined amount necessary for the heat treatment in the next step S8.
Next, in step S8, the shell is heat treated at about 100 ° C. using a plant facility such as a rotary kiln so that the shell does not carbonize (heat treatment step). This is intended to remove and sterilize residual organic matter adhering to the shell. In the present embodiment, the rotary kiln has a kiln length of 12 m (effective length of 11 m), a burner portion of 1 m, and a kiln diameter of φ1.4 m. The supply pitch of the shell was 1 kg / s, and the treatment speed in the kiln was 30 m / min. The initial temperature inside the kiln was 80 ° C., and increased to 120 ° C. during operation due to the heat retaining effect of the furnace and shells. Therefore, it took about 40 minutes to process the shell capacity of 4.5 m ³ . In the present embodiment, the above-described rotary kiln is adopted as the equipment for heat-treating the shell, but not limited to the rotary kiln, an appropriate heat-treatment equipment may be used. Note that the ignition loss at the completion of step S8 is smaller than the ignition loss at the completion of step S6.
In addition, immediately before step S8, the strange odor was reduced to less than 5% at the time of carrying in, but immediately after step S8, the strange odor was reduced to less than 1% at the time of carrying in.

Next, in step S9, the shell is pulverized to a predetermined particle size or less (10 mm or less in the present embodiment) in order to use it as a poultry feed (particle size adjustment step). Specifically, for example, the shell is hit or stepped with a shovel car and finally sieved to recycle only the passing portion as feed. Therefore, after performing the processing of steps S8 and S9, those whose shells are not satisfied as feed are composted. Incidentally, the feed volume generated from the carry when the volume (52.1m ³⁾ is 7.6 m ^3, resource recovery rate was about 15%. Moreover, the weight of the feed produced | generated from the weight at the time of carrying in (31.8t) was 11.8t, and the resource recovery rate was about 37%.

  As a result of analysis of harmful substances in the finally processed feed, as shown in FIG. Moreover, as a result of investigating the chloride ion concentration in the finally treated feed, the chloride ion concentration was an analytical value: 40 to 520 mg-Cl / kg, and less than 1000 mg-Cl / kg.

  As described above, in the bivalve recycling method according to the embodiment of the present invention, step S3 (deodorization step) is performed in which a large amount of bivalve (for example, mussel) is mixed with sawdust and wood chips to obtain a deodorization effect. ), Step S4 (fermentation step) where a large amount of bivalves containing sawdust and wood chips are left in the embankment to rot and decompose organic matter, and a large amount of bivalves containing sawdust and wood chips are washed to remove foreign matter other than shells Since at least the step S5 (cleaning step) for removing the shell and the step S7 (heat treatment step) for heat-treating the shell, it is possible to greatly reduce the processing cost of the bivalve discharged in large quantities, A large amount of bivalve shells can be turned into feed and recycled.

  In the present embodiment, the mussel is described as an example of the bivalve to be processed. However, the present invention is not limited to this, and bivalves such as green mussels, scallops, scallops and clams can also be applied.

Claims (5)

A method for processing and recycling a large amount of discharged bivalves,
A deodorizing step for obtaining a deodorizing effect by mixing sawdust and wood chips into the large amount of bivalves,
A fermentation step that decays and decomposes organic matter by leaving a large number of bivalves including sawdust and wood chips in the form of an embankment;
A cleaning step for cleaning a large amount of bivalves including sawdust and wood chips to remove foreign matter other than shells;
A heat treatment step for heat-treating the shell;
A method for recycling bivalves, comprising:   The bivalve recycling method according to claim 1, further comprising a drying step of drying the shell by sun-drying after the washing step.   3. The bivalve recycling method according to claim 1 or 2, wherein in the fermentation step, a large amount of bivalves including embankment sawdust and wood chips are agitated at regular intervals.   The bivalve recycling method according to any one of claims 1 to 3, wherein in the heat treatment step, the shell is heat-treated at about 100 ° C.   5. The bivalve recycling method according to claim 1, further comprising a particle size adjusting step of pulverizing the shell to a predetermined particle size or less after the heat treatment step.

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