JP2008043919A - Decolorization method of colored beverage drain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decolorization method of colored beverage drain having inexpensive and excellent decolorization effect. <P>SOLUTION: Raw water is introduced into a coagulation reactor 1 where settled sludge of a settling tank 2 of the next stage, PAC, and sodium hydroxide as pH adjusting alkali are added thereto, to keep pH to 6.5-7 for coagulation-reaction. Coagulation-reaction water is introduced into the settling tank 2 for settling separation. Part of the settled sludge is added to the reactor, with the remaining discharged as surplus sludge. Supernatant from the settling tank 2 is filtered in a filter 3, the filtrate of the filter 3 being added with sodium hypochlorite, passed through a catalytic column 5 packed with a catalyst, and taken out as treated water. Peroxide of a metal such as nickel is suitable as the catalyst. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for decolorizing colored beverage wastewater, and more particularly, to a decolorizing method for decolorizing colored beverage wastewater by aggregation treatment and oxidation treatment.

  Conventionally, as a method for removing chromaticity components from water containing chromaticity components, a coagulating and precipitating method by adding a coagulant such as aluminum sulfate or ferric chloride, an adsorption treatment method using activated carbon, chlorine or ozone. There are oxidative decomposition methods using oxidizing agents such as

In addition, in JP-A Nos. 2004-181283, 2004-181284, and 2004-181285, an oxidant such as sodium hypochlorite is added to colored wastewater, and a chrominance component is added by a metal peroxide catalyst. A method of oxidizing treatment is described.
JP 2004-181283 A JP 2004-181284 A JP 2004-181285 A

  In the above-described method for removing the chromaticity component by the coagulation sedimentation treatment in the prior art, there is a problem that sludge is generated during the treatment, and the treatment cost is high. Therefore, it has been desired to solve this problem.

  The present inventor can provide a method for sufficiently reducing the chromaticity without incurring a processing cost by performing the above-described aggregation treatment method in the prior art together with the above-described oxidation treatment method of the chromaticity component. I found it. That is, an object of the present invention is to provide a decolorization treatment method for colored beverage drainage that can obtain an excellent decolorization effect at low cost.

  According to a first aspect of the present invention, there is provided a method for decolorizing a colored beverage wastewater, wherein the colored beverage wastewater is decolorized by an aggregation treatment step using an inorganic flocculant and an oxidation treatment step using an oxidizing agent.

  According to a second aspect of the present invention, there is provided a decolorization treatment method for colored beverage wastewater, wherein the metal hydroxide-containing sludge is added to the reaction tank in the aggregation treatment step.

  According to a third aspect of the present invention, the oxidant is a chlorinated oxidant.

  According to a fourth aspect of the present invention, there is provided a decolorization treatment method for colored beverage wastewater according to any one of the first to third aspects, wherein a metal peroxide is used as a catalyst in the oxidation treatment step.

  In the present invention, an excellent decolorization effect can be obtained at low cost without incurring processing costs.

  Hereinafter, the present invention will be described in more detail.

  Examples of the colored beverage wastewater to be treated in the present invention include wastewater from manufacturing processes such as beer, sparkling liquor, whiskey, shochu, wine, juice, and non-alcoholic carbonated beverages. The chromaticity of this drainage is usually about 50 to 2000.

  In the present invention, this colored beverage wastewater is decolorized by a coagulation treatment with an inorganic coagulant and an oxidation treatment with an oxidant. Any of the aggregation treatment and the oxidizing agent may be performed first.

  As an inorganic flocculant for aggregating this colored beverage wastewater, aluminum compounds such as sulfuric acid bands and PAC (polyaluminum chloride) are suitable because they do not color the treated water. PAC is preferred because a small amount of alkali is sufficient. In addition, since ferric chloride may increase chromaticity, it is not preferable. As the neutralizing alkali, sodium hydroxide or the like is preferable.

  In the case of performing a coagulation treatment with an inorganic coagulant made of an aluminum compound, the amount of coagulation added required for the coagulation treatment can be reduced by adding aluminum hydroxide-containing sludge to the coagulation reaction tank. This is because the added aluminum hydroxide-containing sludge acts as agglomeration nuclei.

  As this aluminum hydroxide containing sludge, the solid-liquid separation sludge (for example, sedimentation sludge) produced when the colored beverage wastewater is subjected to solid-liquid separation after the coagulation reaction is suitable. The solid-liquid separation sludge may be added as it is to the agglomeration reaction tank without dehydration.

When normal colored beverage wastewater is agglomerated with PAC, the amount of PAC added is about 400 to 600 mg / L, but solid-liquid separation sludge is about 1 to ³ L, especially about 1.5 to 2.5 L per 1 m3 of colored beverage wastewater When added, the amount of PAC added is about 200 to 300 mg / L, which is sufficient.

  As an oxidizing agent in the case where the colored beverage wastewater is decolorized with an oxidizing agent, a chlorine-based oxidizing agent is suitable. For example, chlorine, sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, etc. Chlorite salt; Chlorite salt such as sodium chlorite and potassium chlorite; Chlorate salt such as sodium chlorate, potassium chlorate and calcium chlorate; Perchlorite such as sodium perchlorate and calcium perchlorate A chlorate etc. can be mentioned. Among these, hypochlorite has moderate oxidation properties and can be used preferably.

The addition amount of the chlorine-based oxidant is preferably about _{2 to} 50 mg-Cl ₂ / L, particularly about 5 to 50 mg-Cl ₂ / L as a chlorine conversion value.

  In the present invention, it is preferable to add an oxidizing agent to the colored beverage wastewater and to contact the catalyst, preferably a metal oxide catalyst, particularly preferably a metal peroxide catalyst.

  Examples of the metal peroxide catalyst include one or more of cobalt peroxide, nickel peroxide, copper peroxide, silver peroxide, and preferably nickel peroxide and / or cobalt peroxide. In particular, nickel peroxide is preferable.

This metal peroxide catalyst is preferably used by being supported on a carrier such as calcium phosphate compound, zeolite, titania, γ-alumina, α-alumina, preferably a calcium phosphate compound. Here, as the calcium phosphate compound, hydroxyapatite (Ca ₁₀ (PO ₄ ) ₆ OH ₂ ), chloroapatite (Ca ₁₀ (PO ₄ ) ₆ Cl ₂ ), fluoroapatite (Ca ₁₀ (PO ₄ ) ₆ F ₂ ) Such as apatite, calcium phosphate such as calcium monohydrogen phosphate, calcium dihydrogen phosphate, and preferably apatite such as hydroxyapatite, chloroapatite, and fluoroapatite, but other natural minerals such as naturally occurring phosphate ore be able to. These carriers may be used alone or in combination of two or more.

  The amount of metal supported by such a metal oxide supported catalyst is preferably 0.01 to 10% by weight based on the weight of the support. If the supported amount is less than 0.01% by weight, the amount of catalytic metal is small and sufficient catalytic action cannot be obtained, and it is technically difficult to support the supported amount exceeding 10% by weight.

  A method for preparing such a catalyst will be described below with a nickel peroxide-supported catalyst using hydroxyapatite as a carrier.

  The nickel is supported on the hydroxyapatite by bringing it into contact with an aqueous solution of nickel sulfate, nitrate, chloride, or a mixed aqueous solution thereof. Examples of the contact method include a method in which hydroxyapatite particles are immersed in an aqueous nickel compound solution, or a method in which hydroxyapatite particles are filled in a column and the nickel compound aqueous solution is passed in a transient or circulating manner. . The concentration and contact time of the nickel compound aqueous solution may be set so that a necessary amount of nickel is supported on the hydroxyapatite. The hydroxyapatite treated with the aqueous solution of the nickel compound is separated from the aqueous solution and then washed with water as necessary.

  Next, the nickel-supported hydroxyapatite thus obtained is brought into contact with an alkaline aqueous solution containing an oxidizing agent to obtain a nickel peroxide-supported catalyst. As a contact method in this case, a method in which hydroxyapatite carrying nickel ions is immersed in an alkaline aqueous solution containing an oxidizing agent, or a column or the like is filled with this hydroxyapatite and an alkaline aqueous solution containing an oxidizing agent is transiently or For example, a method of circulating water. Here, as the oxidizing agent, various chlorine-based oxidizing agents that generate free chlorine such as sodium hypochlorite, chlorine gas, and chlorine generated by electrolysis are preferably used. Moreover, as aqueous alkali solution, aqueous solution, such as sodium hydroxide and potassium hydroxide, can be used.

  FIG. 1 is a flowchart showing an example of a processing apparatus that performs an oxidation treatment with an oxidizing agent (sodium hypochlorite) after an aggregation treatment with an inorganic flocculant (PAC).

  The raw water is introduced into the agglomeration reaction tank 1, and the sedimentation sludge in the next precipitation tank 2, PAC, and sodium hydroxide as pH adjusting alkali are added to maintain the pH at about 6.5 to 7 and agglomerate. The reaction is processed. The agglomeration reaction water is introduced into the sedimentation tank 2 and subjected to sedimentation treatment. Part of the settled sludge is added to the reaction tank, and the other is discharged as excess sludge. The supernatant water from the settling tank 2 is filtered by the filter 3.

  As the filter medium of the filter 3, anthracite, sand and the like are suitable.

  The filtered water of the filter 3 is added with sodium hypochlorite in the adjustment tank 4, and then passed through the catalyst tower 5 filled with the catalyst, and is taken out as treated water.

  1 is an example of the present invention, and the present invention is not limited to this.

  For example, the catalytic oxidation using a metal oxide catalyst may be performed in a reaction vessel in which a metal oxide catalyst is added and stirred instead of the catalyst tower. Two or more catalyst towers and filter can be provided respectively.

  In addition, according to the decoloring treatment method of the colored beverage wastewater of the present invention, the COD component can be decomposed and removed together with the chromaticity component in the wastewater.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1
According to the flow of FIG. 1, chromaticity 950 and COD _Mn 85 mg / L drinking water manufacturing process waste water were processed as colored drinking water. In addition, as the metal oxide catalyst in the catalyst tower 5, a nickel peroxide-supported hydroxyapatite catalyst prepared by the following method was used.

[Preparation of nickel peroxide-supported hydroxyapatite catalyst]
(1) As a carrier, 1000 g of hydroxyapatite (special grade manufactured by Kishida Chemical Co., Ltd., particle size 0.5 mm) was taken and washed until the SS component disappeared.
(2) Nickel sulfate (NiSO ₄ .6H ₂ O) 112 g (25 g-Ni / 1000 g-dry carrier) was dissolved in 800 mL of ultrapure water. This was added to the carrier washed with water in the above (1) and allowed to stand for 20 hours (2.5 wt% -Ni added to the carrier).
(3) The supernatant liquid of (2) above was discarded.
(4) The carrier separated in (3) above was washed 3 times with 1000 mL of ultrapure water.
(5) 35 g of sodium hydroxide (NaOH) is dissolved in 500 mL of ultrapure water, and 400 mL of a 10 wt% sodium hypochlorite (NaClO) aqueous solution is added to the carrier of (4) above. It was left for 20 hours.
(6) After discarding the supernatant of (5), the separated carrier was washed with ultrapure water until the pH of the washing water reached 10.

The processing conditions were as follows.
Retention time of reaction tank 1: 10 minutes PAC addition amount: 300 mg / L
NaOH addition amount: controlled to be pH 6.5-7 Sludge addition amount: 1.8 L / m ³ -drainage Residence time of sedimentation tank 2: 300 minutes Filter medium of filter 3: Anthracite Residence time of adjustment tank 4: 30 minutes NaClO addition amount: 55 mg-Cl ₂ / L
SV of catalyst tower 5: 10 h ⁻¹

  The treatment results (treated water quality etc.) are shown in Table 1.

Comparative Example 1 (only aggregation treatment with ferric chloride)
In the following Comparative Example 2, treatment was performed in the same manner as in Comparative Example 2 except that 1200 mg / L of ferric chloride (concentration 38 wt%) was added as an inorganic flocculant instead of PAC. The results are shown in Table 1.

Comparative Example 2 (only flocculation treatment with PAC)
A comparative example 2 is obtained by adding PAC 1200 mg / L as an inorganic flocculant and performing only agglutination reaction.
That is, in Example 1, the supernatant water from the sedimentation tank 2 was used as the treated water of Comparative Example 2.
Table 1 shows the water quality measurement results.

  As shown in Table 1, according to the present invention, the chromaticity can be sufficiently reduced.

It is a flowchart which shows the decoloring processing method of the colored beverage waste_water | drain of this invention.

Explanation of symbols

1 reaction tank 2 sedimentation tank 5 catalyst tower

Claims (4)

  A method for decolorizing colored beverage wastewater, wherein the colored beverage wastewater is decolorized by an aggregation treatment step using an inorganic flocculant and an oxidation treatment step using an oxidizing agent.   2. The method for decolorizing drainage of colored beverages according to claim 1, wherein the metal hydroxide-containing sludge is added to the reaction tank in the aggregation treatment step.   3. A decolorizing treatment method for colored beverage drainage according to claim 1, wherein the oxidizing agent is a chlorine-based oxidizing agent.   4. The method for decolorizing treatment of colored beverage wastewater according to any one of claims 1 to 3, wherein a metal peroxide is used as a catalyst in the oxidation treatment step.

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