CN107381925B - Method for treating methylene blue wastewater - Google Patents
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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- C02F9/00—Multistage treatment of water, waste water or sewage
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- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
- C02F1/481—Treatment of water, waste water, or sewage with magnetic or electric fields using permanent magnets
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- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
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- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
- C02F1/488—Treatment of water, waste water, or sewage with magnetic or electric fields for separation of magnetic materials, e.g. magnetic flocculation
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- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
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- C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
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- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
- C02F2101/308—Dyes; Colorants; Fluorescent agents
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- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2301/00—General aspects of water treatment
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Abstract
The invention relates to a method for treating methylene blue wastewater, which comprises the steps of adding tannic acid and metal calcium ions into the methylene blue wastewater, mixing, adding magnetic powder and a flocculating agent, forming magnetic flocculate under an alkaline condition, and performing magnetic separation on the magnetic flocculate by a magnet to achieve the effect of purifying the methylene blue wastewater. The invention has the beneficial effects that: the method is simple to operate, has obvious decolorizing effect, can effectively remove soluble organic dye in dye wastewater and reduce the chemical oxygen consumption in water; low operation cost, short treatment period, high efficiency, simple process, no secondary pollution after flocculation treatment and easy popularization.
Description
Technical Field
The invention relates to a wastewater treatment method, in particular to a method for treating methylene blue wastewater.
Background
Methylene blue is an important organic chemically synthesized cationic dye, is widely applied to the printing and dyeing industry, can be used for dyeing hemp, silk fabrics and paper and coloring bamboo and wood, and can also be used for dyeing biological and bacterial tissues and manufacturing ink, lake and the like. The extensive industrial application of methylene blue causes the industrial wastewater containing the methylene blue to pollute other pure water bodies. The waste water discharged by the industries of printing and dyeing, spinning, dyeing and the like has the characteristics of large water quantity, complex components, high pollutant concentration, deep chromaticity and the like, has certain oxidation resistance and biodegradability, and becomes an important pollution source of each large water area in China. The organic dye wastewater not only has high chroma, but also has high Chemical Oxygen Demand (COD) concentration, is difficult to biodegrade and decolor. Most dyes are also toxic, carcinogenic, teratogenic and mutagenic. At present, the treatment method of the wastewater containing organic dyes mainly comprises a biological method, a coagulation method, an oxidation method, an adsorption method, a membrane separation method and the like.
The existing organic dye wastewater treatment method generally has the problems of complex treatment process, long treatment time, low removal efficiency and high treatment cost. The flocculant or the adsorbent needs more raw materials in the manufacturing process and is expensive, the preparation process is complex, the manufacturing cost is high and the like. The biological treatment of the wastewater containing organic dyes is influenced by factors such as pH value, temperature, dye types and the like, and the biological treatment effect is not ideal due to reasons such as sludge swelling and easy disintegration of conglomerate. The coagulation method has the advantages of high operation cost, large sludge amount, difficult dehydration, narrow applicable pH value range and poor treatment effect on hydrophilic dye. The oxidation method has high cost, the catalyst cannot be recovered, the common oxidant also has the defects of weak oxidation capability, selective oxidation and the like, and impurities are easily introduced in the treatment process to cause secondary pollution. The adsorption method is easily affected by suspended matters, high molecular pollutants, grease and the like in water, and the adsorbent has large dosage and high cost. The membrane separation method is divided into an electrodialysis method, a reverse osmosis method, a nanofiltration method, an ultrafiltration method and the like, wherein the electrodialysis method, the reverse osmosis method and the nanofiltration method have the advantages of high removal rate, capability of recycling the dye in the wastewater and simple process, but the used membrane has high cost and high operation pressure, so that the energy consumption of the membrane method is high, and the industrial application of the membrane method is influenced. And the traditional ultrafiltration method is difficult to remove low-molecular-weight organic pollutants due to large membrane aperture and low removal efficiency. The flocculation decoloring method is widely applied to the decoloring treatment of high-concentration high-chroma wastewater due to low investment cost, large treatment capacity and high decoloring rate. The existing flocculating agents mainly comprise inorganic flocculating agents and organic flocculating agents. The inorganic flocculant mainly comprises ferric chloride, aluminum sulfate, polymeric ferric sulfate and the like, has certain effect on removing suspended matters in sewage, does not decolor soluble dyes in water, and has large dosage and low efficiency. The organic flocculant mainly comprises a decolorizing flocculant such as polyacrylamide and chitosan, but the organic flocculant is expensive and has high treatment cost, and the polyacrylamide has certain toxicity, so that the application is limited to a certain extent. Because the water quality of high-concentration high-chroma wastewater is very complex and a single flocculant cannot achieve an ideal effect easily, the development of a novel composite decolorizing flocculant becomes a research hotspot in the field of water treatment at present.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides a method for treating methylene blue wastewater and a preparation method and application thereof. The method for treating methylene blue wastewater prepared by the invention
The invention aims to provide a method for treating methylene blue wastewater.
The method for treating methylene blue wastewater according to the embodiment of the invention comprises the following steps:
(1) respectively adding tannic acid and calcium salt into methylene blue wastewater, mixing and reacting;
(2) adjusting the pH of the reactant obtained in the step (1) to 9-10 by using an alkaline aqueous solution, mixing and reacting to form a blue precipitate;
(3) adding magnetic powder and a flocculating agent into the reactant obtained in the step (2) for flocculation and precipitation;
(4) and (4) separating and removing the flocculent precipitate obtained in the step (3) by using a magnet to finish the treatment of the methylene blue wastewater.
The method for treating the methylene blue wastewater according to the embodiment of the invention, wherein in the step (1), the concentration of the methylene blue wastewater is 5-100 mg/L; the tannic acid is vegetable tannic acid. The effective content of tannic acid is 80 wt%, that is, tannic acid is added as a mixture containing tannic acid of 80 wt%.
The method for treating methylene blue wastewater according to the embodiment of the invention, wherein the tannin is added in the step (1) in an amount of 0.078 to 0.098mmol per liter of the methylene blue wastewater. Preferably, 0.088mmol of tannic acid per liter of methylene blue wastewater is added, or 150mg of tannic acid solid matter is directly added to each liter of methylene blue wastewater.
According to the method for treating the methylene blue wastewater, in the step (1), the calcium salt is calcium chloride, calcium sulfate, calcium carbonate or calcium nitrate, and the addition amount of the calcium salt is 0.8-1.0mmol of calcium salt per liter of the methylene blue wastewater. Preferably, 0.9mmol calcium salt per liter of methylene blue wastewater is added.
The method for treating methylene blue wastewater according to the embodiment of the invention, wherein the alkaline aqueous solution in the step (2) is an aqueous sodium hydroxide solution, and the concentration of the aqueous sodium hydroxide solution is 40%.
According to the method for treating the methylene blue wastewater, the magnetic powder in the step (3) is ferroferric oxide powder.
The method for treating methylene blue wastewater according to the embodiment of the invention, wherein the flocculant in the step (3) is ferric chloride, ferric sulfate, polymeric ferric chloride, aluminum sulfate or polymeric aluminum sulfate.
The method for treating methylene blue wastewater according to the embodiment of the invention, wherein the magnetic powder is added in the step (3) in an amount of 1.25g per liter of the methylene blue wastewater; the addition amount of the flocculant is 3.5mmol of flocculant added in each liter of methylene blue wastewater.
According to the method for treating the methylene blue wastewater, in the step (3), the flocculation precipitation is performed by firstly performing a stirring process and then performing a standing process, wherein the stirring speed is 150-200r/min, the stirring time is 10-30 s, and the standing time is 30-50 s.
According to the method for treating the methylene blue wastewater, in the step (4), the magnet is a permanent magnet or an electromagnet.
The tannic acid, the calcium chloride, the ferric trichloride and the ferroferric oxide can be prepared into a water solution with a certain concentration, the content of the water solution can be converted into the solid matter amount required by each liter, and the solid matters are directly added into the water solution in proportion. For example, the addition amount of the tannic acid is 0.088 mmol/L of methylene blue wastewater or 150mg of tannic acid solid matter is directly added into each L of methylene blue wastewater.
Plant tannin, also called plant polyphenol, is a complex secondary metabolite of higher plants, is widely distributed in plant bodies, more than 800 common plants containing more tannins are found in China, more than 300 plants containing high tannin content are found in China, and the plant tannin is an important natural product with wide distribution, multiple varieties and large quantity. Each structural unit of the tannin molecule is composed of polycyclic aromatic nucleus and active functional groups, and the active functional groups comprise: phenolic hydroxyl, carboxyl, and the like. The plant tannin has hydrophilic property, surface activity, ion exchange capacity, complexing capacity, adsorption and dispersion capacity and the like, so the plant tannin can be used as a flocculating agent, a scale inhibition and dispersion agent, a corrosion inhibitor and ion exchange resin to be applied to water treatment. Tannin can combine with protein, polysaccharide, nonionic surfactant, and metal ion (especially heavy metal salt) to generate precipitate; in addition, the tannin aqueous solution has the property of semi-colloidal solution, the threshing is negatively charged, the electric potential is changed, and the tannin is natural macromolecular substance, has large volume and is easy to flocculate and precipitate from water, so the tannin aqueous solution can be applied to the treatment of drinking water, waste water and industrial waste water. It is known that tannic acid has a structure containing a large amount of phenolic hydroxyl groups as hydrophilic groups, and the groups have good affinity for cationic dye molecules, heavy metal ions and the like, which is consistent with the mechanism of treating dye wastewater by a flocculation method.
The method for treating the methylene blue wastewater comprises the steps of adding tannic acid with a certain concentration and specific metal ions with a certain concentration into the methylene blue dye wastewater, fully stirring, adding a certain amount of magnetic powder and a flocculating agent, fully mixing under an alkaline condition to form flocculates, generating high-efficiency adsorption with methylene blue dye molecules in water to form stable magnetic flocculates, and carrying out magnetic separation on the magnetic flocculates by a magnet to achieve the effect of purifying the methylene blue dye molecules.
Under alkaline conditions, tannin metal complex formed by tannin and divalent calcium metal ions generates electrostatic adsorption on colored groups in cationic dye wastewater and colored wastewater, so that dye molecules or colored groups are destabilized to form granular colored precipitates.
The method is implemented at normal temperature, has the advantages of simple treatment process, convenient operation, low cost, no secondary pollution, convenient process combination, easy realization of automatic operation and easy popularization.
The method for treating the methylene blue wastewater can play the same role as other flocculants or adsorbents (organic polymers and metal ions), has high separation efficiency, and reduces the risk of secondary pollution.
The invention has the beneficial effects that: the method for treating the methylene blue wastewater is simple to operate, has a remarkable decolorizing effect, can effectively remove soluble organic dye in the dye wastewater and reduce the Chemical Oxygen Demand (COD) in the water;
in the water solution after flocculation treatment, the decolorization rate of methylene blue wastewater reaches more than 97 percent, and the removal rate of Chemical Oxygen Demand (COD) reaches more than 75 percent;
the method for treating the methylene blue wastewater has the advantages of low operation cost, short treatment period, high efficiency, simple process, no secondary pollution after flocculation treatment and easy popularization.
According to the method for treating the methylene blue wastewater, a certain amount of magnetic powder and flocculating agents such as ferric trichloride, ferric sulfate, ferric polysulfate, aluminum sulfate, aluminum chloride and the like are added, magnetic flocculate can be formed with colored precipitates, the precipitates and water are quickly separated by using magnetic force, the dewatering speed of the separated flocculate is high, the ferroferric oxide powder can be recycled and reused, and the input cost is saved.
The method can simultaneously remove organic matters in the dye wastewater and reduce the Chemical Oxygen Demand (COD) concentration in the wastewater.
The residual tannic acid in the treated water can be removed in a biodegradable way, and other harm to the water body can not be caused.
Detailed Description
The technical solution and effects of the present invention will be further described in detail with reference to specific embodiments.
Instruments and chemical reagents used in the invention are commercially available, and all raw materials used in the invention are raw materials commonly used in the industry.
Example 1
A method for treating methylene blue wastewater comprises the following steps:
(1) putting 80ml of methylene blue wastewater with the concentration of 100mg/L into a beaker;
(2) firstly, adding 0.3ml of tannic acid aqueous solution with the concentration of 40g/L and 0.4ml of calcium chloride aqueous solution with the concentration of 20g/L into the solution obtained in the step (1), stirring for 30s at the room temperature at the rotating speed of 150r/min, and uniformly mixing to obtain dye aqueous solution;
(3) adjusting the pH value of the dye aqueous solution obtained in the step (2) to 9 by using a sodium hydroxide (NaOH) aqueous solution with the concentration of 40%, and stirring at the rotating speed of 150r/min for 30s until stable blue granular flocculates are formed in the solution;
(4) adding ferroferric oxide (Fe) into the aqueous solution with the blue granular flocculates obtained in the step (3) according to the proportion of 1.25g/L3O4) 0.1g of powder and 920g/L of ferric trichloride (Fecl)3) Adjusting pH of the wastewater to 9 with sodium hydroxide (NaOH) with concentration of 40% and water solution 0.05ml, stirring at 150r/min for 30s, standing for 30s, magnetically separating flocculate with magnet, and separating flocculate from water solution after 5 min.
The used tannic acid aqueous solution needs to be prepared at present, the storage at normal temperature should not exceed 12 hours, and the tannic acid can be hydrolyzed after being stored for a long time, so that the treatment effect is influenced.
The decolorization rate of methylene blue solution of the water solution after flocculation treatment reaches more than 97 percent, and the removal rate of Chemical Oxygen Demand (COD) reaches more than 75 percent.
Example 2
A method for treating methylene blue wastewater comprises the following steps:
(1) 80ml of methylene blue aqueous solution with the concentration of 100mg/L is taken and placed in a beaker.
(2) Adding 0.3ml of tannic acid aqueous solution with the concentration of 40g/L and 0.4ml of calcium chloride aqueous solution with the concentration of 20g/L into the solution obtained in the step (1), stirring at the room temperature for 30s at the rotating speed of 200r/min, and uniformly mixing to obtain the dye aqueous solution.
(3) And (3) adjusting the pH value of the dye aqueous solution obtained in the step (2) to 9-10 by using a 40% NaOH aqueous solution, stirring for 30s at a rotating speed of 200r/min, and after stable blue granular floccules are formed in the solution.
(4) Adding ferroferric oxide (Fe) into the aqueous solution obtained in the step (3) according to the proportion of 1.25g/L3O4) 0.1g of powder and 920g/L of ferric trichloride (Fecl)3) 0.05ml of aqueous solution, adjusting the pH value to 9-10 by using 40% sodium hydroxide (NaOH), stirring at the rotating speed of 200r/min for 30s, standing for 30s, performing magnetic separation on flocculate by using a magnet, and effectively separating the flocculate from the aqueous solution after 1 min.
The used tannic acid aqueous solution needs to be prepared at present, the storage at normal temperature should not exceed 12 hours, and the tannic acid can be hydrolyzed after being stored for a long time, so that the treatment effect is influenced.
The method for measuring each index comprises the following steps:
and (3) decolorization rate determination: the instrument used for measuring the absorbance is an ultraviolet-visible light spectrophotometer, the absorbance of the methylene blue wastewater before and after treatment is measured at a set wavelength of 502nm by adopting a spectrophotometry method, and the decolorization rate is calculated by a formula.
Chemical oxygen consumption determination: and measuring the Chemical Oxygen Demand (COD) in the methylene blue wastewater before and after treatment by adopting a national standard GB11914-89 COD measuring method, and calculating the Chemical Oxygen Demand (COD) concentrations of the methylene blue wastewater before and after treatment.
The wastewater treatment effect is shown in table 1:
TABLE 1 comparison table of wastewater treatment effect parameters
As can be seen from Table 1, the removal rate of methylene blue was 97.0% and the removal rate of chemical oxygen demand was 75.2% by the method for treating methylene blue wastewater of example 2 of the present invention.
Example 3
A method for treating methylene blue wastewater comprises the following steps:
(1) putting 80ml of methylene blue aqueous solution with the concentration of 50mg/L into a beaker;
(2) firstly, adding 0.3ml of tannic acid aqueous solution with the concentration of 40g/L and 0.4ml of calcium chloride aqueous solution with the concentration of 20g/L into the solution obtained in the step (1), stirring for 30s at the rotating speed of 150-;
(3) adjusting the pH value of the dye aqueous solution obtained in the step (2) to 9-10 by using a sodium hydroxide (NaOH) aqueous solution with the concentration of 40%, and stirring at the rotating speed of 150-;
(4) adding Fe into the aqueous solution obtained in the step (3) according to the proportion of 1.25g/L3O40.1g of powder and 920g/L of ferric trichloride (Fecl)3) 0.05ml of aqueous solution, adjusting the pH value of the wastewater to 9-10 by using 40 percent NaOH, stirring for 2min at the rotating speed of 150-200r/min, standing for 30s, performing magnetic separation on the flocculate by using a magnet, and effectively separating the flocculate from the aqueous solution after 1-5 min.
The used tannic acid aqueous solution needs to be prepared at present, the storage at normal temperature should not exceed 12 hours, and the tannic acid can be hydrolyzed after being stored for a long time, so that the treatment effect is influenced.
The method for measuring each index comprises the following steps:
and (3) decolorization rate determination: the instrument used for measuring the absorbance is an ultraviolet-visible light spectrophotometer, the absorbance of the methylene blue wastewater before and after treatment is measured at a set wavelength of 502nm by adopting a spectrophotometry method, and the decolorization rate is calculated by a formula.
Chemical oxygen consumption determination: and measuring the Chemical Oxygen Demand (COD) in the methylene blue wastewater before and after treatment by adopting a national standard GB11914-89 COD measuring method, and calculating the Chemical Oxygen Demand (COD) concentrations of the methylene blue wastewater before and after treatment.
TABLE 2 comparison table of wastewater treatment effect parameters
As can be seen from Table 2, the removal rate of methylene blue was 97.7% and the removal rate of chemical oxygen demand was 77.1% by the method for treating methylene blue wastewater of example 3 of the present invention.
Comparative example
A method for treating methylene blue wastewater comprises the following steps:
(1) 80ml of methylene blue aqueous solution with the concentration of 100mg/L is taken and placed in a beaker.
(2) 0.3ml of tannic acid aqueous solution with the concentration of 40g/L is added into the solution obtained in the step (1), calcium chloride is not added, and the mixture is stirred for 30s at room temperature at the rotating speed of 150-.
(3) And (3) adjusting the pH value of the dye aqueous solution obtained in the step (2) to 9-10 by using a sodium hydroxide (NaOH) aqueous solution with the concentration of 40%, and stirring at the rotating speed of 150-.
(4) Adding ferroferric oxide (Fe) into the aqueous solution obtained in the step (3) according to the proportion of 1.25g/L3O4) 0.1g of powder and 920g/L of ferric trichloride (Fecl)3) 0.05ml of aqueous solution, then adjusting the pH value of the wastewater to 9-10 by using 40 percent sodium hydroxide (NaOH) aqueous solution, stirring for 2min at the rotating speed of 150-.
The used tannic acid aqueous solution needs to be prepared at present, the storage at normal temperature should not exceed 12 hours, and the tannic acid can be hydrolyzed after being stored for a long time, so that the treatment effect is influenced.
The method for measuring each index comprises the following steps:
and (3) decolorization rate determination: the instrument used for measuring the absorbance is an ultraviolet-visible light spectrophotometer, the absorbance of the methylene blue wastewater before and after treatment is measured at a set wavelength of 502nm by adopting a spectrophotometry method, and the decolorization rate is calculated by a formula.
Chemical oxygen consumption determination: and measuring the Chemical Oxygen Demand (COD) in the methylene blue wastewater before and after treatment by adopting a national standard GB11914-89 COD measuring method, and calculating the Chemical Oxygen Demand (COD) concentrations of the methylene blue wastewater before and after treatment.
TABLE 3 comparison table of wastewater treatment effect parameters
As can be seen from table 3 above, when no calcium chloride is added in the comparative experimental example, both the decolorization rate and the removal rate of the methylene blue dye wastewater are zero, which indicates that in the absence of calcium ions, phenolic hydroxyl groups of tannic acid cannot perform substitution reaction with metal ions, and cannot form a calcium tannate metal complex; the methylene blue molecules cannot be separated from the aqueous solution effectively because the methylene blue molecules cannot be separated from the aqueous solution effectively. The chemical oxygen consumption in the wastewater is increased because of the addition of tannic acid, and because no metal complex is formed with calcium chloride, the tannic acid cannot form precipitate and is separated from the water, so that the content of organic matters in the water body is increased.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. A method for treating methylene blue wastewater is characterized by comprising the following steps:
(1) respectively adding tannic acid and calcium salt into methylene blue wastewater, mixing and reacting; the calcium salt is calcium chloride, calcium sulfate, calcium carbonate or calcium nitrate, and the addition amount of the calcium salt is 0.9mmol of calcium salt added in each liter of methylene blue wastewater;
(2) adjusting the pH of the reactant obtained in the step (1) to 9-10 by using an alkaline aqueous solution, mixing and reacting to form a blue precipitate;
(3) adding magnetic powder and a flocculating agent into the reactant obtained in the step (2) for flocculation and precipitation;
(4) and (4) separating and removing the flocculent precipitate obtained in the step (3) by using a magnet to finish the treatment of the methylene blue wastewater.
2. The method for treating methylene blue wastewater as claimed in claim 1, wherein in the step (1), the concentration of the methylene blue wastewater is 5-100 mg/L; the tannic acid is vegetable tannic acid.
3. The method for treating methylene blue wastewater as recited in claim 1, wherein the amount of tannic acid added in step (1) is 0.088mmol of tannic acid per liter of methylene blue wastewater.
4. The method for treating methylene blue wastewater according to claim 1, wherein the alkaline aqueous solution in the step (2) is an aqueous sodium hydroxide solution, and the concentration of the aqueous sodium hydroxide solution is 40%.
5. The method for treating methylene blue wastewater according to claim 1, wherein the magnetic powder in the step (3) is ferroferric oxide powder.
6. The method for treating methylene blue wastewater as claimed in claim 1, wherein the flocculant in step (3) is ferric chloride, ferric sulfate, polymeric ferric chloride, aluminum sulfate or polymeric aluminum sulfate.
7. The method for treating methylene blue wastewater according to claim 1, wherein the magnetic powder is added in the step (3) in an amount of 1.25g per liter of the methylene blue wastewater; the addition amount of the flocculant is 3.5mmol of flocculant added in each liter of methylene blue wastewater.
8. The method for treating methylene blue wastewater as claimed in claim 1, wherein in the step (3), the flocculation precipitation is performed by firstly performing a stirring process and then performing a standing process, wherein the stirring speed is 150-200r/min, the stirring time is 10s-30s, and the standing time is 30s-50 s.
9. The method for treating methylene blue wastewater as claimed in claim 1, wherein in the step (4), the magnet is a permanent magnet or an electromagnet.
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5158711A (en) * | 1990-01-09 | 1992-10-27 | Mitsubishi Nuclear Fuel Co. | Insoluble tannin preparation process, waste treatment process employing insoluble tannin and adsorption process using tannin |
CN101723501A (en) * | 2009-12-08 | 2010-06-09 | 哈尔滨工业大学 | Coagulation method for processing water body containing plant polyphenol tannate |
CN105601057A (en) * | 2016-03-22 | 2016-05-25 | 湖南大学 | Method for treating methylene blue-containing wastewater |
WO2016126149A3 (en) * | 2015-02-05 | 2016-09-29 | Universite Hassan Premier Settat | Elimination of methylene blue by means of an environmentally friendly method combining adsorption-bioflocculation |
-
2017
- 2017-08-21 CN CN201710720314.2A patent/CN107381925B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5158711A (en) * | 1990-01-09 | 1992-10-27 | Mitsubishi Nuclear Fuel Co. | Insoluble tannin preparation process, waste treatment process employing insoluble tannin and adsorption process using tannin |
CN101723501A (en) * | 2009-12-08 | 2010-06-09 | 哈尔滨工业大学 | Coagulation method for processing water body containing plant polyphenol tannate |
WO2016126149A3 (en) * | 2015-02-05 | 2016-09-29 | Universite Hassan Premier Settat | Elimination of methylene blue by means of an environmentally friendly method combining adsorption-bioflocculation |
CN105601057A (en) * | 2016-03-22 | 2016-05-25 | 湖南大学 | Method for treating methylene blue-containing wastewater |
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