JP2008119633A - Method for treating shellfish flesh-containing waste water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for facilitating discharge of waste water to sea by effectively separating and removing shellfish pulverized pieces, shellfish fine suspended matters and shellfish-originated proteins or the like causing coloring of waste water and odor from shellfish-containing waste water. <P>SOLUTION: A flocculating solidifying agent containing paper sludge incineration ash and gypsum is added to the shellfish-containing waste water produced by treating shellfish, further a cationic polymer flocculant and carbide of paper sludge ash are added thereto, obtained mixture is subjected to treatment of agitating and mixing to produce aggregates and then produced aggregates are separated from the treating liquid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for treating shellfish-containing wastewater, and in particular, to an advantageous method for treating shellfish-containing wastewater generated when fried on the beach (removing pearls from cultured shellfish) in pearl shell culture. is there.

  Traditionally, in the pearl farming industry, in the deep-fried beach work to extract pearls from cultured shells, the shell part with pearls is taken out from cultured shells such as pearl oysters that have been lifted from the sea. The mixture is mixed and stirred in a centrifugal stirrer containing slaked lime and seawater, and pearls are taken out of the processing liquid due to the difference in specific gravity. In addition, the residual liquid containing the crushed shell pieces after the pearls are taken out in this way is simply filtered using a mesh basket with an opening of about 2 to 3 mm, thereby separating the large pieces of shell pieces. On the other hand, the filtrate is discharged into the sea as wastewater.

  However, in the separation method by filtration using the net cage as described above, the fine crushed pieces of shellfish cannot be sufficiently recovered, and such fine crushed pieces are mixed in the filtrate, Since there is also coloring and odor of wastewater that is thought to be based on shellfish fine suspension and shellfish-derived protein, a filtrate containing a large amount of shellfish crushed pieces or shellfish-derived protein, etc. As wastewater, it is considered that discharging into closed inner bays such as pearl oyster farming grounds has a great impact on the environment.

  Therefore, shellfish-containing wastewater containing such shellfish crushed pieces and shellfish-derived protein, for example, as incinerated ash of paper sludge, Portland cement, as disclosed in JP-A-2005-131595, And removing the crushed shellfish pieces, shellfish fine suspensions, shellfish-derived proteins, etc. from the target shellfish-containing wastewater by treatment with a coagulant-solidifying agent composed of gypsum, etc. Can be considered. However, as a result of examination by the present inventors, even when shellfish-containing wastewater is treated using such a flocculant, shellfish-containing fine suspensions specific to shellfish-containing wastewater as described above It became clear that the coloring and odor of the wastewater based on the protein derived from the shellfish and the shellfish cannot be sufficiently separated and removed.

JP 2005-131595 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is from shellfish-containing wastewater, crushed shellfish pieces, shellfish fine suspension, wastewater. It is an object of the present invention to provide a method that can effectively separate and remove protein derived from shell meat, which is the basis of coloring and odor, and easily discharge such waste water to the sea area.

  And, in order to solve such problems, the present invention adds a coagulating solidifying agent containing paper sludge incineration ash and gypsum to shellfish-containing wastewater generated by the treatment of shellfish, and further cationic polymer agglomeration Shellfish meat-containing wastewater characterized in that the agent and paper sludge ash carbide are added, mixed and stirred to form aggregates, and then the resulting aggregates are separated from the treatment liquid. This processing method is the gist thereof.

  Further, according to one of the desirable embodiments of the method for treating shellfish-containing wastewater according to the present invention, the treatment liquid in which the aggregates are generated is respectively mounted on a plurality of rotating shafts arranged in parallel to each other. The agglomerates are supplied onto a large number of elliptical rotating plates, and are subjected to solid-liquid separation using a solid-liquid separation device that performs solid-liquid separation while sequentially transporting the rotating plates according to the rotation direction thereof. Will be taken out.

  Further, according to another preferred embodiment of the present invention, advantageously, the coagulating solidifying agent is 75 to 94% by weight, the cationic polymer flocculant is 1 to 5% by weight, and the paper sludge ash Carbide will be used in a proportion of 5 to 20% by weight.

  In addition, in the present invention, advantageously, at least one selected from the group consisting of Ca, Si and Al is added to the shellfish-containing wastewater. .

  As described above, in the method for treating shellfish-containing wastewater according to the present invention, the shellfish-containing wastewater generated in shellfish farms such as pearl shells is added to the coagulating solidifying agent including paper sludge incineration ash and gypsum. Furthermore, by adding a cationic polymer flocculant, finely crushed pieces of shellfish or fine shellfish suspensions can be advantageously separated and removed from wastewater containing shellfish. In addition, together with the coagulant solidifying agent and the cationic polymer coagulant, carbon sludge of paper sludge ash is further added. Coloring of waste water based on proteins and effective separation and removal of odors have become possible. For this reason, even if such treated wastewater is discharged into the sea as it is, it has little impact on the environment and can effectively reduce the environmental burden, thus greatly contributing to environmental purification. To get.

  By the way, in the present invention, the shellfish-containing wastewater to be treated is a wastewater in which shellfish is dispersed and suspended, which is generated by the treatment of shellfish, and its production process is particularly limited. Rather than, for example, wastewater generated during the operation of pearl shell cultivation, such shellfish-containing wastewater is generally submerged in seawater, crushed pieces of shellfish, fine suspension of shellfish, and shellfish. It contains coloring components, odor components, etc. of wastewater considered to be protein derived from meat. In addition, the ratio of the water content such as seawater and the solid content such as crushed shellfish in such shellfish-containing wastewater is not particularly limited, but generally the moisture content of shellfish-containing wastewater is Those with a ratio of 90% or more are targeted. Further, in the above-mentioned pearl shell culture, the slaked lime may be added to the shellfish-containing wastewater for the purpose of sticking off the pearls from the shellfish portion. Even if such slaked lime and other components are contained in the target shellfish-containing wastewater, there is no problem.

  And in order to perform the treatment of shellfish-containing wastewater as described above according to the present invention, first, coagulation solidification containing paper sludge incineration ash and gypsum is made to the shellfish-containing wastewater generated by the shellfish treatment as described above. The agent will be added.

Here, the paper sludge incineration ash and gypsum used as components of such a coagulating solidifying agent are both well known as coagulating solidifying agents such as clay (for example, JP Among them, paper sludge incineration ash is incinerated ash after paper sludge generated as industrial waste in paper mills and recycled paper factories is incinerated for volume reduction. It can be obtained at low cost and stably at paper mills and recycled paper factories all over the country. Incidentally, the chemical composition of such paper sludge incineration ash, strictly, each factory, also although different from batch to batch, in general, CaO: 10 to 35 wt%, SiO _2: 25 to 35 wt% Al ₂ O ₃ : 23 to 40% by weight, SO ₃ : 3 to 8% by weight, Fe ₂ O ₃ : 1.5 to 4% by weight, MgO: 1.5 to 5% by weight, TiO ₂ : 0.5 1.5 wt%, K ₂ O: 0.3 to 1.0 be comprised of the composition by weight%, etc. in ettringite crystal formation which will be described later, ettringite _{(3CaO · Al 2 O 3 ·} 3CaSO 4 · 32H _It contains CaO and Al ₂ O ₃ which are constituent components of ₂ O).

  In the present invention, such cheaply and stably available paper sludge incineration ash is used as the main component of the agglomerating solidifying agent, and thus the shellfish-containing wastewater according to the present invention is used. This process can be performed at low cost. In addition, by using such paper sludge incineration ash as the main component of the coagulating solidifying agent, it is possible to effectively use paper sludge that has been subjected to processing as industrial waste.

  Examples of the gypsum used together with the paper sludge incineration ash include anhydrous gypsum and hemihydrate gypsum. Among them, anhydrous gypsum is particularly preferably used. That is, in the present invention, as a coagulating solidifying agent, as a component to be added together with paper sludge incineration ash, instead of conventional cement, gypsum is used, but in this way, without using cement, In the treatment method for shellfish-containing wastewater according to the present invention, the problem of elution of hexavalent chromium from a solidifying agent using cement, which has been a concern in recent years by treating shellfish-containing wastewater, There is no need to consider anything.

  Here, the addition ratio of the paper sludge incineration ash and gypsum, which are constituents of the coagulating solidifying agent, is appropriately determined according to the type of the wastewater containing shellfish, and is not limited at all. Advantageously, the paper sludge incineration ash: gypsum is 50: 1 to 1: 1, more preferably 20: 1 to 3: 1 on a weight basis. If it is added beyond this range, the balance of addition of the paper sludge incinerated ash and gypsum is deteriorated, and there is a possibility that the coagulation and solidification action may not be sufficiently obtained.

In the method for treating shellfish-containing wastewater according to the present invention, the coagulation-solidifying mechanism by the coagulant-solidifying agent containing paper sludge incineration ash and gypsum as described above is not yet completely clear, but the shellfish-containing wastewater In addition, when paper sludge incineration ash and gypsum as described above are added, the hydratable minerals in paper sludge incineration ash, gypsum and water in the wastewater react to produce ettringite (3CaO.Al ₂ O _3. 3CaSO ₄ · 32H ₂ O) is formed, and the acicular crystals of such ettringite grow as crystals around the crushed pieces of shellfish contained in shellfish-containing wastewater as a core, thereby making shellfish in wastewater It is considered that aggregates composed of crushed pieces and the like and an aggregation solidifying agent are generated.

In addition, in the present invention, following such ettringite crystal formation, calcium hydroxide generated by the hydration reaction of the hydratable inorganic substance in the paper sludge incineration ash and silica in the paper sludge incineration ash By the pozzolanic reaction between alumina and gypsum, calcium silicate hydrate (nCaO.SiO ₂ .mH ₂ O), calcium aluminate hydrate (3CaO.Al ₂ O ₃ .6H ₂ O) and ettringite ( 3CaO.Al ₂ O ₃ .3CaSO ₄ .32H ₂ O) and the like are formed, and this is considered to improve the durability of the resulting aggregate.

  And, in the method for treating shellfish-containing wastewater according to the present invention, in addition to the above-described coagulating solidifying agent, the cationic polymer flocculant and Paper sludge ash carbides are added.

  In this regard, examples of the cationic polymer flocculant include polyacrylamide cation-modified products such as polyacrylamide Mannich-modified products, Hoffman degradation products and amide group sulfomethylated products, and cationic vinyl lactam-acrylamide copolymers. Various publicly known ones can be exemplified, and various types of commercially available products can be selected as appropriate. In particular, Hymo Lock MP manufactured by Hymo Co., Ltd. is advantageously used.

  Thus, in the method for treating shellfish-containing wastewater according to the present invention, in addition to the above-mentioned coagulating solidifying agent, such a cationic polymer flocculant is further added. The shellfish fine suspension etc. present in the inside can be advantageously produced as agglomerates together with the shellfish crushed pieces, etc., so that the wastewater containing shellfish can be treated effectively. It will be.

  Further, the paper sludge ash carbide used together with the cationic polymer flocculant is obtained by carbonizing the paper sludge incinerated ash as described above by further heating in a reducing atmosphere in a carbonization furnace. Similar to the above-described paper sludge incineration ash, it can be obtained at low cost and stably in various paper factories and recycled paper factories.

  And according to the present invention, in addition to the above-mentioned flocculating and solidifying agent and cationic polymer flocculating agent, by adding the carbide of paper sludge ash, the organic matter adsorbing effect of such a carbide, shellfish-derived protein It was possible to effectively separate and remove the coloring and odor of the wastewater containing shellfish, which is considered to be based on the above. In addition, since the paper sludge ash carbide is available at a low cost, the treatment of shellfish-containing wastewater can be realized advantageously at low cost. Effective use could also be realized.

  Here, as the addition ratio of the above-mentioned coagulating solidifying agent, cationic polymer flocculant and paper sludge ash carbide, considering the moisture content of the wastewater containing shellfish to be treated, additives such as slaked lime, etc. The flocculent solidifying agent is preferably 75 to 94% by weight, the cationic polymer flocculant is 1 to 5% by weight, and the paper sludge ash carbide is advantageously 5 to 20%. It is desirable to be used in a percentage by weight. By using at such a ratio, the treatment of shellfish-containing wastewater can be performed more advantageously.

  In addition, when the addition ratio of the coagulating solidifying agent is less than the above range, there is a possibility that the coagulation solidifying effect due to the addition of the coagulating solidifying agent may not be sufficiently exhibited, and when it is larger than the above range The addition ratio of the cationic polymer flocculant and the paper sludge ash carbide is relatively decreased, and the effect of adding them may not be sufficiently exhibited, which is not desirable. In addition, when the addition ratio of the cationic polymer flocculant is less than the above range, the addition of the cationic polymer flocculant may not sufficiently obtain the aggregation effect of the shellfish fine suspension or the like. Therefore, it is not desirable, and when the amount is larger than the above range, the resulting aggregates become fine and the sedimentation property is deteriorated, and the viscosity is increased by the addition of a large amount of polymer. This is not desirable because of fear. Furthermore, if the added ratio of the paper sludge ash carbide is less than the above range, coloring and odor separation and removal in the shellfish-containing wastewater may not be sufficient, and more than the above range. If it is too high, it is difficult to disperse the carbides well in the wastewater containing shell meat, which may cause a problem that the organic substance adsorption effect of the carbides of such paper sludge ash is reduced. Absent.

  In addition, as the total amount of the flocculant solidifying agent, cationic polymer flocculant and paper sludge ash carbide, the amount of solids such as crushed shellfish in the wastewater containing shellfish to be treated is taken into consideration. In general, the total amount of the agglomerating solidifying agent, the cationic polymer flocculant, and the paper sludge ash carbide is 0 with respect to 100 parts by weight of the shellfish-containing wastewater. It will be added in an amount of 5-10 parts by weight. When the amount added is less than the above range, it is difficult to sufficiently separate the shellfish-derived protein, which is the basis of coloring and odor of shellfish crushed pieces, shellfish fine suspension and shellfish-containing wastewater. If the amount is larger than the above range, it is not possible to improve the agglomeration effect by adding more than that, and there is a possibility that the cost may be wasted.

  Furthermore, in the method for treating shellfish-containing wastewater according to the present invention, advantageously, for shellfish-containing wastewater, at least one selected from the group consisting of a Ca component, a Si component, and an Al component, Will be added. In this case, the calcium content is cocoon calcium, shell calcium, eggshell calcium, limestone, etc., and the Si content is silica powder, glass powder, amorphous silica powder, diatomaceous earth, clay, etc. Aluminum residual ash, natural mineral of alumina silicate, etc. are exemplified, and they are appropriately selected from these and used.

  In this way, by further adding Ca, Si, or Al to the shellfish-containing wastewater, the above-described coagulation-solidifying effect by the coagulation-solidifying agent can be exhibited more advantageously. That is, as described above, in the production of ettringite by the reaction of paper sludge incineration ash, gypsum and water in wastewater, and subsequent generation of calcium silicate hydrate, calcium aluminate hydrate, etc. by pozzolanic reaction, By further adding a Ca component, a Si component, or an Al component to adjust the inorganic component, these reactions can proceed more advantageously. In addition, such addition amount and addition ratio of Ca, Si, or Al are appropriately determined based on the addition amount of paper sludge incineration ash, its chemical composition, and the addition amount of gypsum. It will be.

  In addition, in the method for treating shellfish-containing wastewater according to the present invention, in addition to the additives as described above, various additives conventionally used in flocculants can be added as necessary. You may add within the range which does not inhibit the objective. Examples of such additives include pH regulators such as alkaline inorganic compounds such as sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, and aluminum hydroxide, sulfate bands (aluminum sulfate), and secondary chloride. Inorganic flocculants such as iron and polyaluminum chloride, anionic surfactants such as alkylbenzene sulfonate, lignin sulfonate and stearate, and polyoxyethylene alkylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyalkylene Examples thereof include surfactants such as nonionic surfactants such as block copolymers, dispersants such as tripolyphosphates and hexametaphosphates, and binders such as polyvinyl alcohol resins.

  And in the method for treating shellfish-containing wastewater according to the present invention, the above-mentioned coagulating solidifying agent, cationic polymer flocculant, and paper sludge ash carbide are added to the shellfish-containing wastewater to be treated. Then, it is processed by mixing and stirring to produce agglomerates. However, when adding these agglomerating solidifying agents, etc., no special method is required and a conventionally known method is used. Accordingly, they may be added in an arbitrary order, or some or all of them may be added in advance after mixing them. Moreover, even if it exists in the method of the process by mixing and stirring, it will not be limited at all and any conventionally well-known method is employable.

  Further, after such treatment by mixing and stirring, the aggregates produced by the formation of ettringite and the like as described above are separated from the treatment liquid. The method for separating the aggregates is not particularly limited, and any conventionally known method can be adopted. In the present invention, the treatment liquid in which the aggregates are generated is used. Is supplied to a plurality of elliptical rotating plates respectively mounted on a plurality of rotating shafts arranged in parallel to each other, and is sequentially transported in accordance with the rotation direction of the rotating plates, and the solid-liquid separation is performed. A technique of taking out the agglomerates by performing solid-liquid separation using a separation apparatus is advantageously employed.

  That is, in the method for treating shellfish-containing wastewater according to the present invention, for example, a treatment apparatus having a configuration as shown in FIGS. Is preferably used.

  Specifically, as is clear from these drawings, the solid-liquid separation device 2 has a plurality of rotating shafts 8 arranged in parallel to each other in a horizontal plane with respect to the frame 6 of the device main body, so that the shaft can rotate freely. On the other hand, a large number of elliptical rotating plates 4 are mounted on the rotating shaft 8 at a predetermined interval, and between the adjacent rotating plates 4 and 4, the horizontal direction in FIG. A guide member 10 having an upper surface as a guide surface is arranged. Then, by rotating the respective rotating shafts 8 in the same direction, the treatment liquid produced by the aggregates introduced into the feeding surface formed by the upper peripheral surface of the rotating plate 4 attached to each shaft is While being lifted from below to the peripheral surface of the rotating plate 4 in a row, it is conveyed rightward in FIG. 1 along the upper surface of the guide member 10. And the process liquid which the said aggregate produced | generated is the process of moving the upper surface of the guide member 10 and the rotating plate 4, and the clearance gap between the rotating plate 4 and the guide member 10 in the clearance gap between the rotating plates 4 and 4 and Water and other liquid components are flowed out and filtered downward from the gap between the peripheral surfaces of the adjacent rotating plates 4 and discharged to the outside, while the solid component collected on the guide member 10 is the rotating plate. 4 while being sent on the peripheral surface of FIG. 4, it is filtered and dehydrated sequentially, and can be taken out from the solid-liquid separation device 2 as an agglomerate having a reduced water content.

  In such a solid-liquid separation device 2, the guide member 10 is configured such that the upper surface thereof is a smooth guide surface, while the elliptical phase of the rotating plate 4 is sequentially changed for each adjacent axis. They are shifted by 90 degrees (see FIG. 1), so that while the rotating plate 4 rotates, the feeding surface of the adjacent rotating plate 4 changes in the feeding direction while sequentially forming a waveform during the rotation. It is configured as follows. Further, an upper portion of the casing of the apparatus main body is provided with a pressing device 18 having a structure in which an arm 14 having a weight 12 attached to the tip is pivotally supported by a shaft 16 so as to be swingable up and down. The apparatus 18 is swung following the vertical movement of the peripheral surface of the rotating plate 4 so that it can press the agglomerates to be further dewatered.

  Thus, the agglomerate taken out from the solid-liquid separator 2 has a water content reduced to about 75% or less, and is easy to handle. On the other hand, the filtrate discharged to the outside is advantageously separated and removed from the coloring and odor of shellfish-containing wastewater based on crushed pieces of shellfish, shellfish fine suspensions and shellfish-derived proteins. is there.

  Further, in the present invention, the agglomerates taken out by solid-liquid separation using the solid-liquid separation apparatus as described above are resuspended in water such as tap water, and the above-described solid-liquid separation is performed again. You may make it perform solid-liquid separation by an apparatus. By repeating such treatment two or three times, the salt content and the like contained in the finally obtained aggregate can be easily removed. And the aggregate from which the salt content was removed can be used effectively as an auxiliary material for agriculture and horticulture.

  Furthermore, as described above, slaked lime is added to the shellfish-containing wastewater to be treated in the present invention when the shellfish portion is crushed, and the filtrate may have a high pH value. In such a case, it is desirable that the filtrate separated by solid-liquid separation is neutralized and then discharged into the sea area.

  Hereinafter, some examples of the present invention will be shown and the present invention will be more specifically clarified, but the present invention is not limited by the description of such examples. It goes without saying. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the above specific description. It should be understood that improvements can be made.

-Examples 1-4, Comparative Examples 1,2-
A wastewater containing shellfish containing about 5% concentration of shellfish, which is discharged in the operation of taking pearls from pearl oysters, was prepared. In addition to this, a paper sludge incineration ash (Oji Paper Co., Ltd., Yonago Mill) and gypsum, as well as a polyacrylamide polymer flocculant (trade name: Hymo Lock MP, Hymo Co., Ltd.) and / or gypsum Or carbon sludge of paper sludge ash (made by Oji Paper Co., Ltd., Yonago Mill) is added so as to have the amounts (%) shown in Table 1 and Table 2 below, respectively, mixed, stirred and reacted, thereby The resulting aggregate was filtered through a 2 mm mesh sieve. The obtained filtrate was visually observed and evaluated according to the following criteria. The results are shown in Table 1 and Table 2 below.
○: Shellfish crushed pieces, shellfish fine suspension, filtrate coloring and odor are sufficiently separated and removed ×: Shellfish crushed pieces, shellfish fine suspension, filtrate coloring and Odor is not sufficiently separated and removed

-Comparative Example 3-
To the shellfish-containing wastewater prepared in Example 1, paper sludge ash carbide (made by Oji Paper Co., Ltd., Yonago Mill) and baked scallop shells were added so as to have the amount (%) shown in Table 2 below. The mixture was stirred and reacted, and the resulting aggregate was filtered through a 2 mm mesh sieve. For the obtained filtrate, the coagulation effect was evaluated in the same manner as in Example 1. The results are also shown in Table 2 below.

-Comparative Example 4-
To the shellfish-containing wastewater prepared in Example 1, a paper sludge ash carbide (Oji Paper Co., Ltd., Yonago Mill) and a polyacrylic acid-based polymer flocculant as an anionic polymer flocculant (trade name: Hymolock MP, Hymo Co., Ltd.) was added so as to have an amount shown in Table 1 below, mixed and stirred to react, and the resulting aggregate was filtered through a 2 mm mesh sieve. For the obtained filtrate, the coagulation effect was evaluated in the same manner as in Example 1. The results are also shown in Table 1 below.

  As is clear from the results of Table 1 and Table 2, the wastewater containing shellfish is treated using the agglomeration solidifying agent (paper sludge incineration ash and gypsum), the cationic polymer flocculant and the paper sludge ash carbide. (Examples 1 to 4), the coloring and odor of wastewater considered to be based on the crushed pieces of shellfish containing wastewater containing shellfish, the fine suspension of shellfish and the shellfish-derived protein, It was found that it can be separated and removed.

On the other hand, when either one of the cationic polymer flocculant and the carbide of paper sludge ash is added together with the flocculent solidifying agent (paper sludge incineration ash and gypsum) at a ratio other than the advantageous addition ratio in the present invention (comparison) Examples 1 and 2), when a baked scallop shell is used instead of the cationic polymer flocculant according to the present invention (Comparative Example 3), and further when an anionic polymer flocculant is used (Comparative Example 4) In that case, a good aggregation effect could not be obtained.

It is a schematic explanatory drawing which shows an example of the solid-liquid separator used in the processing method of shellfish containing wastewater according to this invention. It is AA cross-section explanatory drawing in FIG.

Explanation of symbols

2 Solid-liquid separator 4 Rotating plate 6 Frame 8 Rotating shaft 10 Guide member 12 Weight 14 Arm 16 Shaft 18 Squeezing device

Claims (4)

  Add flocculant solidifying agent including paper sludge incineration ash and gypsum, and add cationic polymer flocculant and paper sludge ash carbide to the shellfish-containing wastewater generated by shellfish treatment and mix. A method for treating shellfish-containing wastewater, wherein the treatment is performed by stirring to form aggregates, and the resulting aggregates are separated from the treatment liquid.   While supplying the treatment liquid in which the aggregates are formed on a number of elliptical rotating plates each mounted on a plurality of rotating shafts arranged in parallel to each other, the processing liquid is sequentially conveyed in accordance with the rotation direction of the rotating plates. The method for treating shellfish-containing wastewater according to claim 1, wherein the agglomerates are taken out by performing solid-liquid separation using a solid-liquid separation apparatus that performs solid-liquid separation.   The coagulant solidifying agent is used in a proportion of 75 to 94% by weight, the cationic polymer flocculant is used in a proportion of 1 to 5% by weight, and the carbide of the paper sludge ash is used in a proportion of 5 to 20% by weight. Or the processing method of the wastewater containing shellfish of Claim 2. The at least 1 sort (s) chosen from the group which consists of Ca content, Si content, and Al content is further added with respect to the said wastewater containing shellfish, The Claim 1 thru | or 3 characterized by the above-mentioned. To treat wastewater containing shellfish.

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