JP2015063421A - Method for manufacturing organic fertilizer and organic feed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an additive-free organic fertilizer containing no acid or alkali component and an organic feed in which Cd is efficiently removed from a soft body part of a scallop at a low cost, and Cd waste liquid is treated without polluting environment.SOLUTION: A manufacturing method of an organic fertilizer and an organic feed includes: a first process of adding a predetermined volume of water to a soft body part of a scallop containing cadmium, pulverizing the body, and allowing the body part to self-digest the pulverized soft body part; a second process of adding chelate fiber to the soft body part which self-digested in the first process to allow the fiber to adsorb the cadmium; and a third process of heating the soft body part from which cadmium was removed in the second process.

Description

  The present invention relates to a method for producing an organic fertilizer and an organic feed from which cadmium has been removed from a soft body part of a scallop, and more particularly, to a method for producing an additive-free organic fertilizer and an organic feed that do not contain an acid or alkali component at a low cost.

  Scallops are an important edible resource that is produced over 500,000 tons per year and accounts for almost 10% of the total catch in Japan. The main edible portion of the scallop is only 15% by weight of the scallop, and the remaining shell (50% by weight) and soft body part (35% by weight) are discarded as processing waste. This soft body part contains a large amount of useful components such as proteins and amino acids, and it is desirable to reuse it for fertilizer and feed.

  However, the uro (midgut gland) contained in the soft body part contains 100 mg / kg (dry state) of biocondensed cadmium (Cd), so it can be reused as it is for fertilizer and feed. Not only can it be done, but it cannot be discarded as processing waste.

  Therefore, as a method for removing cadmium from the soft body portion, a technique has been proposed in which cadmium can be removed simultaneously from the soft body portion and the liquid phase by stirring and mixing the chelate resin in an acidic aqueous solution without heating (see Patent Document 1). .) In addition, fish and shellfish protein is self-digested in a fermenter adjusted to a temperature of 20 to 50 ° C. with a pH of 4 or less, and this protein is decomposed into an amino acid solution, and heavy metals such as cadmium contained in this amino acid solution are added to the chelating agent. Has been disclosed (see Patent Document 2).

Japanese Patent No. 4000346 JP-A-6-106155

  Generally, in order to liberate cadmium from a protein, the pH is adjusted to 4 or less using an acid. Furthermore, in order to prevent cadmium once released from rebinding to the protein and further increase the release of cadmium, the pH must be lowered and made acidic. In that respect, in Patent Document 1, it is performed under the condition of pH 5.0 to 3.0 in order to remove cadmium in a short time. Moreover, in patent document 2, in addition to adjusting hydrochloric acid to pH 4.0-3.8, protease is utilized in order to release cadmium effectively. That is, in these patent documents, since cadmium is liberated using an acidic chemical, not only the quality of fertilizer and feed is reduced, but also the chemical cost increases.

  Further, the chelating agent has a property of easily adsorbing metal ions selectively depending on pH. In that respect, in Patent Document 1, since alkali is finally added to make the pH from about 5.0 to about 3.0, the chemical cost increases accordingly. Moreover, in patent document 2, since alkali is added in order to adjust pH 4.0 to pH 8.0-9.0, the chemical cost will increase accordingly.

  The liberated cadmium becomes cadmium ion. Therefore, if cadmium ions are adsorbed on the chelating agent, rebinding with protein can be prevented. However, since the added chelating agent also attaches metal ions such as iron ions and manganese ions in addition to cadmium ions, there is an upper limit on the amount of cadmium ions adsorbed per unit area. In that respect, in Patent Document 1 and Patent Document 2, the addition amount of the chelating agent depends on the dissolved amount of cadmium. If there is too much chelating agent, not only minerals necessary for organic fertilizer and organic feed are removed. The cost of chelating agents increases. Furthermore, since the chelating agent is extremely small, it is difficult to recover even if it is added.

  Moreover, since the cadmium removed from the soft body part is mixed in the waste liquid, it cannot be drained as it is. Although there is no description in this point in patent document 1 and patent document 2, the technique which processes waste liquid at low cost without polluting an environment is calculated | required.

  Therefore, a first object of the present invention is to provide a method for producing an additive-free organic fertilizer and organic feed containing no acid or alkali components at low cost. The second object of the present invention is to provide a method for producing organic fertilizer and organic feed by removing cadmium efficiently and at low cost. The third object of the present invention is to provide a method for producing an organic fertilizer and an organic feed by treating a waste liquid containing cadmium without causing environmental pollution.

  In order to solve the above-mentioned problems, the present inventor has intensively studied and tested, and as a result, added only an appropriate amount of water to the soft body part of the shell, shells, strings, and other useful parts, and pulverized. It was found that heating at a constant temperature activates the action of the digestive enzyme contained in the soft body part to release cadmium from the protein without using chemicals such as acids. Moreover, not only has it been easy to remove cadmium from the treatment liquid by using a fibrous chelating agent, but this chelate fiber can be washed, dehydrated and regenerated for use to remove cadmium adsorbed on the chelate fiber. It has been found that it is highly efficient in producing organic fertilizers and organic feeds, and cadmium is separated from the waste liquid containing cadmium produced in the production thereof and can be safely treated.

  That is, the method for producing organic fertilizer and organic feed according to the present invention includes a first step of adding a predetermined amount of water to a soft body part of scallops containing cadmium and pulverizing, and self-digesting the crushed soft body part, A second step of adding a chelate fiber to the soft body part self-digested in the step to adsorb the cadmium, and a third step of heat-treating the soft body part from which cadmium has been removed in the second step, To do.

  The water added in the first step is desirably 1/10 to 3/10 weight of the soft body part.

  It is desirable that the processing residue pulverized in the first step is self-digested by stirring at 40 to 50 ° C. for at least 5 hours.

  It is desirable that the chelate fiber added in the second step is 1 to 4% by weight of the soft-digested soft body part.

  It is desirable to adsorb cadmium by adding chelate fiber in the second step and stirring for 1 to 3 hours.

  A fourth step of collecting the waste liquid containing cadmium when the chelate fiber adsorbed with cadmium in the second step is regenerated, and a metal trapping material and activated carbon are added to the waste liquid containing cadmium collected in the fourth step. Preferably, the method further includes a fifth step of solid-liquid separation of the activated carbon containing the cadmium collected by the metal collecting material.

  It is desirable that the metal collection material of the fifth step is 90 to 181.5 ppm by weight of the waste liquid and the activated carbon is 0.25 to 0.5% by weight of the waste liquid.

  Here, the “soft body” of scallop means the remaining part after separating useful parts such as scallops and strings from the soft body excluding the scallop shell. (Midgut gland), gonad, mantle, sputum, heart, kidney, etc. “Chelating fiber” means a fiber containing a chelating agent capable of adsorbing metal ions, that is, a chelating ion exchange fiber, and means having an iminoacetic acid group as a functional group for performing ion exchange. . “Regeneration treatment” means removal of metal ions such as cadmium on the chelate fiber using an acid such as hydrochloric acid when the cadmium adsorption ability of the chelate fiber is reduced. “Metal trapping material” means a material that reacts with and captures heavy metal ions contained in the waste liquid to insolubilize it.

  In the method for producing organic fertilizer and organic feed according to the present invention, cadmium is liberated by the self-digesting enzyme of the soft part without using any organic acid or inorganic acid, so that the quality of the organic fertilizer and organic feed can be maintained, Since the cost of chemicals does not increase, it can be processed at low cost. Also, since the amount of water added is reduced as much as possible, fuel such as heavy oil during drying can be reduced. The chelating fiber that removes cadmium can be used continuously until it is washed and dehydrated until the adsorption capacity of the cadmium decreases, and the chelating fiber that has further decreased the adsorption capacity of the cadmium can be regenerated, removed and regenerated by removing the cadmium. And the cost of the chelate fiber can be reduced.

It is a figure which shows the flow which extract | collects organic feed and organic fertilizer from a soft body part. It is a figure which shows the flow which processes the waste liquid containing a cadmium. It is a table | surface which shows the state after the self-digestion of a soft body part. It is a table | surface which shows the relationship between the time and temperature of the suitable soft body self-digestion, and the process by a chelate fiber. It is a table | surface which shows the test data and the comparison data when processing the waste liquid containing cadmium.

  With reference to FIG. 1, the manufacturing method of the organic fertilizer and organic feed by this invention is demonstrated. In FIG. 1, steps A to C are shown. As shown in step A of FIG. 1, the remaining soft body part obtained by separating a shell, a scallop, and a part of a useful part such as a string is collected from a scallop (A1). Next, water of 1/10 to 3/10 weight of the soft part collected in (A1) is added to the soft part and pulverized with a mixer (A2). And the soft body part grind | pulverized by (A2) is self-digested by stirring at 40-50 degreeC for 5 to 25 hours (A3).

  Here, since the soft body part is low in fluidity and muddy, it is difficult to stir. Therefore, by adding an appropriate amount of water to the soft body part, the fluidity is improved and the stirring efficiency is increased. Therefore, the self-digesting enzyme becomes easy to work in the entire soft body part, and cadmium is easily released from the protein. Moreover, if the fluidity of the pulverized soft body part is good, the liberated cadmium is easily adsorbed on the chelate fiber, so that the removal efficiency is improved.

  That is, the amount of water added to the soft body part affects the liberation of cadmium and the adsorptivity to the chelate fiber. When the amount of water is too small, the fluidity of the pulverized soft body part becomes low and stirring becomes insufficient. For this reason, not only the treatment with the self-digesting enzyme becomes longer, but also the liberation of cadmium may be insufficient. On the other hand, if the amount of water is too large, the concentration of the autolytic enzyme will decrease, and the reaction with the protein may be delayed. In addition, the activity of various bacteria becomes active and it rots. Furthermore, when manufacturing a fertilizer or feed from the liquid containing the protein which removed the cadmium with the chelate fiber, the energy cost which dries a moisture increases. For this reason, the amount of water added to the soft body part is preferably 1/10 to 3/10 weight, more preferably 1/5 weight of the soft body part. In terms of conversion, in consideration of fluctuations in the amount of water contained in the soft body part to be processed, the amount of water is preferably 10 g to 30 g, more preferably 20 g, relative to 100 g of the soft body part.

  If the temperature of the pulverized soft body part to be stirred is too low, the function of the enzyme is weakened, so that there is a possibility that the liberation of cadmium may be insufficient. On the other hand, if the temperature of the pulverized soft body part is too high, the protein is denatured, so that the self-digesting enzyme may be deactivated and cadmium may be insufficiently liberated. For this reason, the temperature of the pulverized soft body part to be stirred is preferably 40 to 55 ° C, and preferably 45 ° C.

  The time for stirring the pulverized soft body part is required to be at least 5 hours in consideration of the progress of self-digestion, may be 15 to 25 hours, and preferably 20 hours.

  The B process is performed after the A process. That is, 1% by weight of chelate fiber is added to the soft digestion liquid of the soft body part (B1). Next, the soft body part to which the chelate fiber is added in (B1) is stirred at room temperature for 1 to 3 hours (B2). And after a soft body part is stirred by (B2), a chelate fiber is taken out from a self-digestion liquid, and a chelate fiber is dehydrated (B3). After dehydration in (B3), (1) a soft body part from which cadmium has been removed and (2) a chelate fiber to which cadmium has been adsorbed are obtained.

  The chelate fiber has a function of preferentially adsorbing cadmium ions in the liquid released from the protein under conditions near neutrality, and sodium ions are bound to the chemifiber-like iminoacetic acid groups. When metal ions that are easier to bind than sodium are present in the liquid, sodium ions are released into the liquid and the metal ions are adsorbed. Chelate fibers preferentially adsorb cadmium ions, but metal ions that are relatively easy to adsorb to chelate fibers such as iron ions and manganese ions after the concentration of cadmium ions in the solution is reduced. Adsorbs after the drop. If metal ions other than cadmium are adsorbed on the chelate fiber, the ability to adsorb cadmium ions will be reduced accordingly, and the frequency of the chelate fiber regeneration process may increase. Moreover, some metal ions other than cadmium are useful for plants as minerals. If they are adsorbed and removed by chelating fibers, the mineral content of the resulting fertilizer will be reduced. The chelate fiber having a reduced ability to adsorb cadmium can be reused if it is regenerated by washing with an acid such as hydrochloric acid.

  If too little chelating fiber is added, cadmium removal may be insufficient. On the other hand, when there are too many chelate fibers, other metal ions are adsorbed as described above, so the removal rate of cadmium does not increase in proportion to the amount of chelate fibers added. In view of the removal rate of cadmium, nutrients necessary for plants such as minerals, and cost, the amount of chelate fiber added is preferably 1 to 4% by weight, more preferably 1% by weight of the soft body.

  Cadmium contained in the solution cannot be removed simply by adding the chelating fiber. This is because cadmium ions are not attracted to the fibrous chelate surface, and are not adsorbed unless cadmium is brought into contact with the chelate surface. Then, you may change the time which stirs a soft body part according to the removal degree of cadmium. However, if the treatment is carried out for a long time, self-digestion progresses and there is an influence such as propagation of bacteria and spoilage. Therefore, it is preferably 1 to 3 hours, more preferably 2 hours.

  The C process is performed after the B process. That is, the soft body part from which cadmium has been removed is subjected to heat treatment (C1). This heat treatment inactivates the enzyme in the soft body part, so that the fertilizer and feed can be prevented from being contaminated with bacteria. And it becomes a raw material of organic fertilizer and organic feed (C2).

  FIG. 2 is a flowchart for treating a waste liquid containing cadmium generated when the chelate fiber is regenerated. In FIG. 2, the process D is illustrated. Step D (D1) is a waste liquid containing cadmium remaining after regenerating the chelate fiber adsorbed with B step (B3) (2) cadmium in FIG. First, 90 to 181.5 ppm by weight of heavy metal collection material is added to a waste liquid containing cadmium and stirred for 5 minutes (D2). Next, 0.25 to 0.5% by weight of activated carbon is added to the waste liquid containing cadmium stirred in (D2) and stirred for 30 minutes (D3). Finally, the waste liquid containing cadmium stirred in (D3) is centrifuged at 3500 G for 10 minutes to separate activated carbon containing cadmium (D4).

Since the waste liquid contains cadmium, it cannot be discharged as factory wastewater. Therefore, in general, a metal collecting material is added to the waste liquid and combined with cadmium. Thereafter, a polymer aggregating agent is added to agglomerate and precipitate the metal scavenger bound to cadmium.
However, in this method, it is necessary to reliably perform the coagulation sedimentation with special equipment, and lacks versatility. Therefore, when using relatively cheap activated carbon, which does not require special equipment, as an alternative to polymer agglomerates, it was discovered that it has a cadmium collection effect.

  Fig. 3 shows the test results of the soft body part that was self-digested at 45 ° C for 20 hours after adding 1/5 weight of water (2 kg) to the soft body part (10 kg) and pulverizing with a mixer. Indicates. 3 (1) shows the ratio of the amount of nitrogen contained in the soft body part, the amount of nitrogen is 1.86%, FIG. 3 (2) shows the amount of cadmium contained in the soft body part, and the amount of cadmium is 2 .77 mg / kg, FIG. 3 (3) shows the cadmium concentration of the soft body part, and it was confirmed that the cadmium concentration was 1.49 ppm / nitrogen 1%. The reference value for the cadmium content of the fertilizer is higher than the reference value because it is 0.8 ppm or less per 1% of nitrogen.

  FIG. 4 shows the relationship between the time and temperature spent for soft body self-digestion and cadmium removed by adding 1 wt% chelate fiber to each soft body part. In this test, the self-digestion time was 5 hours, 10 hours, 15 hours, and 20 hours, and the temperatures were 40 ° C., 45 ° C., 50 ° C., and 55 ° C., respectively, and 1 wt% chelate fiber (Nichibi ion exchange fiber (chelate type) : IEF-IAc (H), (Na)) This fiber easily binds to cadmium near neutrality and can be preferentially adsorbed over other metal ions. 1) shows the cadmium concentration of the soft body part, and it was found that the average value of the cadmium concentration was low when self-digested at 45 ° C., and this cadmium concentration became lower as time was spent. The cadmium concentration per 1% of nitrogen was shown, and the average value of the cadmium concentration per 1% of nitrogen was low when self-digested at 45 ° C. It was found that the cadmium concentration decreased as time was spent. ) Excludes cadmium Indicates the rate, high average value of the removal rate of cadmium when autolyzed at 45 ° C., was found to be higher removal rate of cadmium as time consuming.

  FIG. 5 shows test data and comparison data obtained by measuring the amount of cadmium in the waste liquid containing cadmium processed in step D of FIG. In FIG. 5, the test results of test samples 1 to 6 and comparative samples 7 to 8 are shown. As the heavy metal scavenger, epoch rock made of Miyoshi oil and fat is used. In Test Samples 1 to 3, cadmium concentrations were measured when 181.5 ppm by weight of heavy metal collection material and 0.75 wt%, 0.5 wt%, and 0.25 wt% of activated carbon were added, respectively. In this case, the cadmium concentrations were all 0.04 mg / kg. Moreover, in the test samples 4-6, the cadmium density | concentration at the time of adding 90.75 weight ppm of heavy metal collection materials and 0.75 weight%, 0.5 weight%, and 0.25 weight% of activated carbon was measured, respectively. In this case, it was found that the cadmium concentration was within the range of 0 to 0.1 mg / kg.

  On the other hand, in Comparative Sample 7, the cadmium concentration was measured when 181.5 ppm by weight of the heavy metal collecting material and 0.1% by weight of the polymer coagulant were added, and no activated carbon was added. In this case, the cadmium concentration was 0.28 mg / kg. In Comparative Sample 8, the cadmium concentration when no heavy metal collector, polymer coagulant, or activated carbon was added was 8.05 mg / kg.

Claims (7)

A first step of adding a predetermined amount of water to the soft body part of scallop shell containing cadmium and pulverizing, and self-digesting the crushed soft body part;
A second step of adsorbing the cadmium by adding a chelate fiber to the soft body part that is self-digested in the first step;
And a third step of heat-treating the soft body part from which cadmium has been removed in the second step. The method for producing an organic fertilizer and organic feed according to claim 1, wherein the water added in the first step is 1/10 to 3/10 weight of the soft body part. The method for producing organic fertilizer and organic feed according to claim 1 or 2, wherein the processing residue pulverized in the first step is self-digested by stirring at 40 to 50 ° C for at least 5 hours. The method for producing an organic fertilizer and organic feed according to any one of claims 1 to 3, wherein the chelate fiber added in the second step is 1 to 4% by weight of the soft body part that has been self-digested. The method for producing organic fertilizer and organic feed according to any one of claims 1 to 4, wherein chelate fibers are added in the second step and cadmium is adsorbed by stirring for 1 to 3 hours. A fourth step of collecting waste liquid containing the cadmium when the chelate fiber adsorbed with cadmium in the second step is regenerated.
A fifth step of solid-liquid separating the activated carbon containing the cadmium collected in the metal collecting material by adding a metal collecting material and activated carbon to the waste solution containing the cadmium collected in the fourth step. The manufacturing method of the organic fertilizer and organic feed of any one of Claims 1 thru | or 5 characterized by these. The organic fertilizer according to claim 6, wherein the metal collecting material in the fifth step is 90 to 181.5 ppm by weight of the waste liquid, and activated carbon is 0.25 to 0.5% by weight of the waste liquid. And an organic feed production method.

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