JP6322398B2 - Waste water treatment agent and waste water treatment method - Google Patents

Description

  The present invention relates to treatment of wastewater containing various heavy metals and wastewater containing dyeing / coloring wastewater and pollutants using an inorganic wastewater treatment agent.

  Wastewater containing various pollutants, harmful components, coloring components, etc. discharged from various industries, sewers, civil engineering and construction sites, etc. is subject to the regulations of wastewater standards. After removing the coloring components, etc., it is discharged into public water areas. In recent years, drainage standards have tended to be strengthened due to the increase in environmental conservation, and some municipalities have adopted environmental standard values in addition to drainage standards.

  Wastewater containing various pollutants, harmful components, coloring components, etc. discharged from various industries, sewers and civil engineering construction sites is generally treated with an inorganic flocculant such as polyaluminum chloride (PAC) as the first step. Add to charge neutralize (condensation effect), add acid or alkali to adjust pH, add polymer flocculant in the second step, crosslink and adsorb (floc), coagulate and precipitate, process Has been. Moreover, the process which has two or more processes which add an inorganic flocculant and a polymer flocculent is also performed (patent documents 1-4).

  However, the agglomeration and precipitation treatment as described above has a problem that many chemicals and treatment steps are used, the treatment apparatus such as a stirring tank and the precipitation tank becomes excessive, and the installation place becomes large.

  In addition, even in the past, wastewater treatment agents and treatment methods that are effective for treating specific heavy metals and pollutants (Patent Documents 4 to 7), in recent years, many heavy metals, pollutants, and harmful components There are also wastewaters in which coloring components coexist or are combined. For this reason, it is necessary to develop a wastewater treatment agent and a wastewater treatment method that can quickly treat such difficult wastewater and that is simple, low-cost, and has high removal performance.

JP 2009-195775 A JP 2009-220067 A JP 2011-245431 A Japanese Patent No. 5170461 JP 2000-246267 A JP 2010-82507 A JP 2006-167598 A

  As described above, wastewater containing at least one kind of heavy metals, pollutants, harmful components, colored components, etc. can coexist and be separated quickly, and harmful trace components can be removed simultaneously. Development of wastewater treatment agents that can be used is desired.

  Accordingly, an object of the present invention is to provide a clean and quick supernatant that does not require special equipment or a large amount of equipment, and drains wastewater in which at least one kind of heavy metals, pollutants, harmful components, and coloring components coexist or are combined. An object of the present invention is to provide a wastewater treatment agent and a wastewater treatment method that can be separated into water and agglomerated precipitates and that can simultaneously remove harmful trace components in the wastewater.

  Therefore, as a result of various studies to solve the above-mentioned problems of the prior art, the present inventor has found that calcium aluminum is discharged into wastewater in which at least one or more heavy metals, pollutants, harmful components, coloring components, etc. coexist or are combined. By adding a wastewater treatment agent composed of nate, aluminum sulfate, lime and polymer flocculant, solid-liquid separation into clean supernatant water and coagulated sediment quickly without the need for special equipment or equipment And the present invention has been completed by finding that harmful trace components in waste water can be removed at the same time.

  That is, the present invention provides the following [1] to [6].

[1] 100 parts by mass of calcium aluminate,
10 to 110 parts by mass of aluminum sulfate,
A wastewater treatment agent comprising 80 to 1500 parts by mass of slaked lime or 5 to 200 parts by mass of quick lime and 1 to 10 parts by mass of a polyacrylamide-based amphoteric polymer flocculant.
[2] The wastewater treatment agent according to [1], further comprising one or more selected from 10 to 200 parts by mass of ferrous sulfate and 0.5 to 20 parts by mass of alkali metal phosphate .
[3] for the wastewater 100 parts by weight, (1) or (2) a waste water treatment agent according, waste water treatment method comprising adding 0.05 to 3.0 parts by weight.
[4] The waste water treatment agent described in [1] or [2] is boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb ), Wastewater treatment used to treat wastewater containing at least one selected from heavy metals selected from cadmium (Cd) and total mercury (T-Hg) , pollutants, harmful components other than heavy metals and colored components Way .
[5] Boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd), total mercury (T-Hg) A wastewater treatment agent according to [1] or [2] is added to wastewater containing at least one selected from heavy metals selected from the group consisting of heavy metals, contaminants , harmful components other than heavy metals and coloring components, and the heavy metals A wastewater treatment method characterized by coagulating and precipitating harmful components and colored components other than pollutants and heavy metals and separating them into solid and liquid.
[6] Wastewater is boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd), total mercury (T -Hg) containing at least one selected from heavy metals selected from Hg) , pollutants, harmful components other than heavy metals and coloring components, and a method for removing water quality standard target components [5] Wastewater treatment method.

  If the wastewater treatment agent of the present invention is used, at least one or more heavy metals, pollutants, harmful components, coloring components, etc. coexist or without requiring special facilities such as a centrifuge and a large amount of facilities. The wastewater to be combined can be quickly solid-liquid separated into clean supernatant water and coagulated sediment, and harmful trace components in the wastewater can be removed at the same time.

It is a figure which shows a heavy metal removal test flow.

  The wastewater treatment agent of the present invention contains 100 parts by mass of calcium aluminate, 10 to 110 parts by mass of aluminum sulfate, 5 to 1500 parts by mass of lime, and 1 to 20 parts by mass of the polymer flocculant.

Calcium aluminate is a compound mainly composed of CaO and Al ₂ O ₃ . For example, 3CaO · Al ₂ O ₃ , CaO · Al ₂ O ₃ , 12CaO · 7Al ₂ O ₃ , 11CaO · 7Al ₂ O ₃ · CaF _2, etc. can be used. Calcium aluminate with a high content of CaO and Al ₂ O ₃ is preferable, 12CaO · 7Al ₂ O ₃ , 11CaO · 7Al ₂ O ₃ · CaF ₂ is more preferable, and 12CaO is more preferable. · 7Al ₂ O ₃ is more preferred. Calcium aluminate may be crystalline or amorphous, but amorphous calcium aluminate is preferred.
While fineness of the calcium aluminate is not particularly limited, but the Blaine specific surface area from the viewpoint of the aggregation-promoting effect, preferably 3000~9000cm ² / g, more 4000~6000cm ² / g is more preferable.

Aluminum sulfate may be either a hydrate represented by Al ₂ (SO ₄ ) ₃ .nH ₂ O as a chemical component or an anhydrous salt represented by Al ₂ (SO ₄ ) ₃ . Preferably, a hydrate having n of 14 to 18 is preferable because it is excellent in the removal effect and aggregation effect of harmful substances. Generally, it is not particularly limited as long as it is a powdered reagent called a sulfate band and an industrial product, and those based on JIS K 1423 are more preferable.
Content of aluminum sulfate is 10-110 mass parts with respect to 100 mass parts of calcium aluminate in a waste water treatment agent, Preferably it is 10-100 mass parts. If the content of aluminum sulfate is less than 10 parts by mass, the pH of the drainage tends to be high, and if it exceeds 110 parts by mass, a sufficient aggregation promoting effect cannot be obtained. Aluminum sulfate is in terms of hydrate total weight.

Examples of lime include slaked lime, quick lime, and limestone fine powder, and slaked lime and quick lime are preferable.
While fineness of the lime is not particularly limited, and is preferably 3000~10000cm ² / g in Blaine specific surface area from the point of removing effect of aggregation promoting effect and harmful components, 4000~8000cm ² / g is more preferable.
The content of lime is 5 to 1500 parts by mass with respect to 100 parts by mass of calcium aluminate in the waste water treatment agent. When using slaked lime, content of slaked lime is 80-1500 mass parts with respect to 100 mass parts of calcium aluminate in a waste water treatment agent, Preferably it is 80-1000 mass parts. If the content of slaked lime is less than 80 parts by mass, sufficient coagulation precipitation effect and harmful component removal effect cannot be obtained, and if it exceeds 1500 parts by mass, the pH of the wastewater tends to increase. Moreover, when using quicklime, content of quicklime is 5-200 mass parts with respect to 100 mass parts of calcium aluminates in a waste water treatment agent, Preferably it is 5-100 mass parts. If the content of quicklime is less than 5 parts by mass, sufficient coagulation precipitation effect and harmful component removal effect cannot be obtained, and if it exceeds 200 parts by mass, sufficient aggregation promotion effect cannot be obtained.

Examples of the polymer flocculant include a cationic polymer flocculant, an anionic polymer flocculant, a nonionic polymer flocculant, and an amphoteric polymer flocculant having a cationic group, an anion group, and a nonionic group at the same time. In the present invention, it is preferable to use an amphoteric polymer flocculant having all the features of a cation, an anion, and a nonionic flocculant in order to deal with a wide variety of wastewater treatment.
The content of the amphoteric polymer flocculant is preferably 1 to 20 parts by mass and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of calcium aluminate in the wastewater treatment agent from the viewpoint of aggregation performance and economy.

  In the wastewater treatment agent of the present invention, one or two kinds selected from a reducing agent and an alkali metal phosphate with respect to 100 parts by mass of calcium aluminate for the purpose of further detoxifying and removing harmful components. The above can be used together.

By using the reducing agent in combination with calcium aluminate, an excellent detoxifying effect and removal effect can be obtained. Examples of the reducing agent include ferrous sulfate, sodium thiosulfate, formic acid, and oxalic acid. Ferrous sulfate can be preferably used because it is easy to handle and relatively inexpensive. Ferrous sulfate includes ferrous sulfate heptahydrate with seven crystal waters and ferrous sulfate monohydrate with one crystal water, but ferrous sulfate monohydrate with high storage stability. It is preferable to use a hydrate.
The content of ferrous sulfate monohydrate is preferably 10 to 300 parts by mass, more preferably 10 to 200 parts per 100 parts by mass of calcium aluminate in the wastewater treatment agent from the viewpoint of reduction effect and economy. Part by mass.

Examples of the alkali metal phosphate include readily soluble salts such as sodium phosphate and potassium phosphate. In the present invention, a good effect of removing harmful components can be obtained by blending alkali metal phosphate. As the alkali metal phosphate, potassium phosphate represented by the following formulas (1) to (3) is preferable, and since it is excellent in the removal effect of harmful components, phosphoric acid diphosphate represented by the following formula (2). More preferred is potassium hydrogen.
The content of potassium dihydrogen phosphate is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of calcium aluminate in the waste water treatment agent.

K ₂ HPO ₄ (1)
KH ₂ PO ₄ (2)
K ₃ PO ₄ (3)

  The wastewater treatment agent of the present invention only needs to contain the calcium aluminate, aluminum sulfate, lime and polymer flocculant, and should not affect the cohesiveness of the wastewater and the removal effect of harmful components such as heavy metals. , Other ingredients such as chelating agent, ordinary cement, early strong cement, super early strong cement, moderate heat cement, low heat cement, portland cement such as sulfate resistant cement, mixed cement such as blast furnace cement, silica cement, fly ash cement , White cement, eco-cement, alumina cement, colloidal cement, ultrafine cement, special cement such as cement-based solidified material, gypsum such as anhydrous gypsum, dihydrate gypsum, hemihydrate gypsum, natural or artificial zeolite, montmorillonite, kaolin, It may contain clay minerals such as bentonite.

By using the wastewater treatment agent of the present invention, it is possible to remove harmful substances in the wastewater, that is, components that are regulated as harmful substances by the water quality standards set by the Ministry of the Environment (water quality standard target components). Examples of the water quality reference target component include boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd), Examples include total mercury (T-Hg).

  The wastewater to be treated by the present invention is wastewater that coexists or is combined with at least one selected from a large number of heavy metals, pollutants, harmful components, and coloring components. According to the wastewater treatment according to the present invention, heavy metals and other harmful components contained in the wastewater can be removed together with the pollutants and coloring components, so that the wastewater may contain a wide variety of harmful components. . The wastewater to be treated in the present invention includes wastewater discharged from the industry and sewers, various manufacturing industries such as steel industry, paper manufacturing industry, aluminum manufacturing industry, semiconductor manufacturing industry, mining industry, heavy metal recovery industry and recycling industry. Waste water from civil engineering construction sites or livestock industry.

  In the wastewater treatment method of the present invention, the wastewater treatment agent is added to the wastewater that coexists or is combined with at least one selected from a large number of heavy metals, pollutants, harmful components, and coloring components, and is coagulated and precipitated. It is a method of separation. 0.05-3.0 mass parts is preferable with respect to 100 mass parts of waste water, and, as for the addition amount of a waste water treatment agent, 0.1-1.0 mass part is more preferable.

  The waste water to which the waste water treatment agent is added is preferably mixed in order to promote removal of heavy metals and harmful components and aggregation of pollutants and coloring components. The mixing means is not particularly limited, and a normal stirrer may be used. Since the wastewater after the addition of the wastewater treatment agent is promoted to aggregate, precipitation occurs immediately after the stirring is stopped, and the wastewater is separated into two layers. If solid-liquid separation is performed by using, for example, a sedimentation separation tank or the like without using a special apparatus, heavy metals, contaminants, and coloring components are removed from the liquid layer (water layer).

  The liquid layer (water layer) after the treatment has a significantly reduced content of heavy metals and harmful components, and can be discharged as it is if the pH is adjusted as necessary. On the other hand, the solid layer may be recycled as long as it is acceptable as a part of the cement raw material.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples.

The materials and analytical methods used in the examples and comparative examples are as follows.
<Materials used>
(1) Wastewater Municipal waste incineration ash washing water Black deinking wastewater (abbreviation: wastewater a): Paper company Blue colored wastewater (abbreviation: wastewater b): Paper company Green colored wastewater (abbreviation: wastewater c): Paper company (2) Wastewater treatment agent Calcium aluminate (abbreviation: CA): Taiheiyo Material Co., Ltd. Aluminum sulfate (abbreviation: ALS): Daimei Chemical Co., Ltd. Quick lime (abbreviation: CAO): Taiheiyo Material Co., Ltd. CAH): powder reagent manufactured by Kanto Chemical Co., Ltd. Ferrous sulfate monohydrate (abbreviation: FSH): manufactured by Fuji Titanium Industry Co., Ltd. potassium dihydrogen phosphate (abbreviation: KHP): powder reagent manufactured by Kanto Chemical Co., Inc. Abbreviation: PFA): Polyacrylamide amphoteric polymer flocculant
Keith Lock RP-AM7
Chelating agent (abbreviation: KA): Chelating agent for waste water Commercial product Polyaluminum chloride (abbreviation: PAC): General commercial product

<Analysis method>

  The materials used were blended in the proportions shown in Table 2 to produce the wastewater treatment agent of this example and the wastewater treatment agent of the comparative example.

(Heavy metal removal effect of wastewater treatment agent)
Using a municipal waste incineration ash washing water containing various heavy metals, a heavy metal removal test was conducted by adding a wastewater treatment agent. A predetermined amount of waste water treatment agent was added to the municipal waste incineration ash washing water, stirred for 3 minutes, and allowed to stand. The supernatant water after the coagulation sedimentation was filtered with a 0.45 μm membrane filter to prepare a test solution for heavy metal analysis. For comparison, a similar test was performed using a commercially available chelating agent for waste water. When a chelating agent was used, polyaluminum chloride (PAC) was separately added as an aggregating agent recommended by the chelating agent manufacturer, and coagulation precipitation was performed. FIG. 1 shows a flow of the heavy metal removal test. Table 3 shows the heavy metal removal test results.

  As is apparent from Table 3, 100 parts by mass of calcium aluminate (CA), 10 to 110 parts by mass of aluminum sulfate (ALS), 5 to 1500 parts by mass of lime (CAO or CAH) and 1 to 1 of polymer flocculant (PFA). If a wastewater treatment agent containing 20 parts by mass was used, harmful heavy metals in municipal waste incineration ash washing water could be removed, and environmental standard values related to water pollution could be cleared. It was also found that heavy metals that cannot be removed by chelating agents can be removed.

(Coagulation and precipitation effect of wastewater treatment agent)
500 ml of 3 types of colored suspended wastewater discharged from a paper company is placed in a beaker, and the amount of wastewater treatment agent adjusted according to the formulation shown in Table 4 is set for the amount of wastewater, and the amount of coagulation sedimentation effect and The pH, turbidity and chromaticity of the supernatant water were confirmed. Confirmation of the effect of coagulation sedimentation is whether or not the sedimentation of aggregates is completed within 1 minute after standing by adding a predetermined wastewater treatment agent and stirring with respect to 100 parts by weight of the target wastewater. Was evaluated. Table 5 shows the measurement results.

  As is apparent from Table 5, by adding 0.05 to 0.1% by mass of the wastewater treatment agent of the present invention to 100 parts by mass of each wastewater, aggregation can be promoted remarkably, and the supernatant after aggregation precipitation It can be seen that water also satisfies the water quality standards of pH, turbidity and chromaticity.

Claims (6)

100 parts by weight of calcium aluminate,
10 to 110 parts by mass of aluminum sulfate,
A wastewater treatment agent comprising 80 to 1500 parts by mass of slaked lime or 5 to 200 parts by mass of quick lime and 1 to 10 parts by mass of a polyacrylamide-based amphoteric polymer flocculant.   Furthermore, the waste water treatment agent of Claim 1 which contains 1 type, or 2 or more types chosen from 10-200 mass parts of ferrous sulfate and 0.5-20 mass parts of alkali metal phosphates. Waste water treatment method for wastewater 100 parts by weight, the waste water treatment agent according to claim 1 or 2, wherein the addition 0.05 to 3.0 parts by weight. The wastewater treatment agent according to claim 1 or 2 is boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd ), A wastewater treatment method used for treating wastewater containing at least one selected from heavy metals selected from total mercury (T-Hg) , pollutants, harmful components other than heavy metals and coloring components. Selected from boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd), and total mercury (T-Hg) A wastewater treatment agent according to claim 1 or 2 is added to wastewater containing at least one selected from heavy metals, pollutants, harmful components other than heavy metals and coloring components, and the heavy metals , pollutants and heavy metals are added. A wastewater treatment method characterized by coagulating and precipitating harmful components and colored components other than the above and solid-liquid separation. Wastewater is boron (B), fluorine (F), arsenic (As), selenium (Se), hexavalent chromium (Cr ⁶⁺ ), lead (Pb), cadmium (Cd), total mercury (T-Hg) heavy metals selected from pollutants, which contains at least one or more selected from toxic components and coloring components other than heavy metals, waste water treatment method according to claim 5, wherein a process for removing water quality standards target component .

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