Method for advanced oxidation and digestion of wastewater containing metal paints

Abstract

The invention discloses a method for deep oxidation and digestion of wastewater containing metallic paint, which belongs to the technical field of wastewater treatment. The method comprises the following steps: a first step of adjusting the pH of the wastewater containing metallic paint with a 10% by mass hydrochloric acid solution, then adding a Fenton reagent to adjust the system to neutrality, thereby obtaining oxidized wastewater; a second step of adding a water treatment agent to the oxidized wastewater, stirring the wastewater at a speed of 100-200 r / min for 3-5 minutes under light, allowing the wastewater to settle for 1-1.5 hours, and performing sand filtration to complete the treatment; and a dual oxidation treatment of Fenton oxidation and treatment with the water treatment agent is performed to achieve deep treatment, thereby achieving good treatment effect on the wastewater containing metallic paint. When the water treatment agent acts on the wastewater, the residual organic matter can be treated by modifying the photocatalytic performance of the carrier, and the introduced quaternary ammonium salt cations can flocculate pollutant particles by electrostatic adsorption, thereby improving the treatment effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the sewage treatment technical field, specifically relates to a kind of metal-containing paint sewage advanced oxidation digestion method. BACKGROUND

[0002] The COD of metal-containing paint sewage is very high, reaching 160,000 mg / L, or even higher, and the content of harmful organic matter is also high, which is difficult to degrade, and the content of solid material is also high. For example, paint-containing wastewater. This kind of wastewater is difficult to treat, contains a large amount of resin, surfactant, organic solvent and auxiliary agent, and other suspended solids and difficult-to-biodegrade macromolecular organic matter, and the composition of pollutants is complex, with poor recyclability.

[0003] The current traditional method for treating paint-containing wastewater is dilution and coagulation. However, due to the large volume of wastewater after dilution, a large amount of chemicals need to be added, resulting in high treatment cost, which is not suitable for wide application. Coagulation method is to directly add coagulant and flocculant to the paint-containing wastewater for coagulation treatment, but the effluent quality is difficult to meet the safe discharge standard. SUMMARY

[0004] To solve the above technical problems, the present application provides a kind of metal-containing paint sewage advanced oxidation digestion method.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] A kind of metal-containing paint sewage advanced oxidation digestion method, comprising the following steps:

[0007] First step: adjust the pH of metal-containing paint sewage to 4-4.5 with 10% mass fraction hydrochloric acid solution, then add Fenton reagent, stir uniformly and oxidize for 1-1.5 h, then add 10% mass fraction sodium hydroxide dropwise to adjust the system to neutral, to obtain oxidized sewage;

[0008] Second step, add water treatment agent to the oxidized sewage, stir at a speed of 100-200 r / min under light for 3-5 min, stand for 1-1.5 h, sand filter, and the treatment is completed.

[0009] The water treatment agent is prepared by the following steps:

[0010] Step S1, tetrabutyl titanate is added to tetraethyl silicate, stirred at a constant speed for 5 min, then triethanolamine is added, continues to stir for 30 min, then slowly drops tetraethyl ammonium hydroxide, stirs at a constant speed for 30 min, then ages at room temperature for 24 h, after aging is completed, is transferred to a 100℃ oven to dry for 24 h, a gel is prepared, then is transferred to a reaction kettle, hydrothermal at 180℃ for 8 h, then calcined at 550-600℃ for 12 h, a catalytic carrier is prepared, the amount ratio of tetrabutyl titanate, tetraethyl silicate, triethanolamine and tetraethyl ammonium hydroxide is controlled to be 21.02-21.28 mL: 72-82 mL: 25.40-25.48 mL: 16.20-16.58 mL;

[0011] In step S1, tetraethyl silicate is used as a silicon source, triethanolamine is used as a template agent, and tetraethyl ammonium hydroxide is used as an auxiliary template agent, Si-O bonds are gradually formed between tetraethyl silicate molecules through a hydrothermal synthesis method, and finally a porous material with a three-dimensional mesoporous structure is synthesized, tetrabutyl titanate is used as a titanium source, and titanium dioxide prepared by a gel method is used as a photocatalytic component to form a catalytic carrier, the carrier uses a porous material as a carrier and titanium dioxide as a photocatalytic component, and when used for sewage treatment, the residual organic matter after Fenton oxidation can be further treated to improve the removal effect of the organic matter.

[0012] Step S2, the catalytic carrier is added to a 90% ethanol aqueous solution, KH570 is added, stirs at a constant speed for 15-30 min, then the pH of the system is adjusted until the pH is 4, then stands for 1 h, the temperature is raised to 60-70℃, stirs at a constant speed and reacts for 4 h, after the reaction is completed, a modified catalytic carrier is prepared, and the amount ratio of the catalytic carrier, KH570 and the ethanol aqueous solution is controlled to be 1-2 g: 3-6 mL: 10-15 mL;

[0013] In step S2, the surface of the catalytic carrier is modified by the silane coupling agent KH570 to introduce carbon-carbon double bonds on the surface of the catalytic carrier;

[0014] Step S3, polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate and the modified catalytic carrier are added to deionized water, ultrasonic dispersion is performed for 30 min, the temperature is raised to 40-45℃, ammonium persulfate is added, and the reaction is performed under a nitrogen atmosphere for 20-24 h, after the reaction is completed, a water treatment agent is prepared, and the amount ratio of polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate, the modified catalytic carrier, ammonium persulfate and deionized water is controlled to be 1-2 mmol: 1-2 mmol: 0.05-0.08 mmol: 2-3 g: 3-5 g: 0.03-0.05 mmol: 20-30 mL.

[0015] The polypropylene, the methacryloyl ethoxy trimethyl ammonium chloride as the monomer, the polydimethyl diallyl ammonium chloride as the stabilizer, and the ammonium persulfate as the initiator in step S3 are polymerized, the carbon-carbon double bond on the modified catalytic carrier is introduced, the quaternary ammonium salt cation is introduced on the surface of the modified catalytic carrier by polymerization, the water treatment agent is prepared, and when the water treatment agent acts on sewage, residual organic matter can be treated by the photocatalytic performance of the modified carrier, and the quaternary ammonium salt cation introduced can flocculate pollutant particles by electrostatic adsorption, thereby improving the treatment effect.

[0016] Further, the concentration of ferrous sulfate in the Fenton reagent in the first step is 1-1.2 g / L, and the concentration of hydrogen peroxide is 5-10 mL / L.

[0017] Further, the concentration of the water treatment agent in the second step is 1-2 g / L.

[0018] The present application discloses a method for deep oxidation and digestion of sewage containing metal paint, which realizes deep treatment through dual oxidation treatment of Fenton oxidation and water treatment agent treatment, and has good treatment effect on sewage containing metal paint. The water treatment agent is prepared by using tetraethyl silicate as a silicon source, triethanolamine as a template agent, and tetraethyl ammonium hydroxide as an auxiliary template agent. Si-O bonds are gradually formed between tetraethyl silicate molecules by hydrothermal synthesis method, and finally a porous material with three-dimensional mesoporous structure is synthesized. Tetra-n-butyl titanate is used as a titanium source, and titanium dioxide prepared by gel method is used as a photocatalytic component to form a catalytic carrier. The carrier uses a porous material as a carrier and titanium dioxide as a photocatalytic component. The surface of the catalytic carrier is modified by silane coupling agent KH570 to introduce carbon-carbon double bonds on the surface of the catalytic carrier. Finally, ammonium persulfate is used as an initiator, and polypropylene, methacryloyl ethoxy trimethyl ammonium chloride, and carbon-carbon double bonds on the modified catalytic carrier are polymerized to introduce quaternary ammonium salt cations on the surface of the modified catalytic carrier. The water treatment agent is prepared. When the water treatment agent acts on sewage, residual organic matter can be treated by the photocatalytic performance of the modified carrier, and the quaternary ammonium salt cation introduced can flocculate pollutant particles by electrostatic adsorption, thereby improving the treatment effect. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Embodiment 1: A method for deep oxidation and digestion of sewage containing metal paint, comprising the following steps:

[0021] The first step is to adjust the pH of the paint wastewater containing metal to 4 with a 10% hydrochloric acid solution, then add Fenton reagent, stir uniformly and oxidize for 1h, then add 10% sodium hydroxide to adjust the system to neutral, and prepare the oxidized wastewater;

[0022] The second step is to add a water treatment agent to the oxidized wastewater, stir at 100r / min under light for 3min, stand for 1h, sand filter, and the treatment is completed.

[0023] The concentration of ferrous sulfate in the Fenton reagent in the first step is 1g / L, and the concentration of hydrogen peroxide is 5mL / L.

[0024] The concentration of the water treatment agent in the second step is 1g / L.

[0025] The water treatment agent is prepared by the following steps:

[0026] Step S1, add tetrabutyl titanate to tetraethyl silicate, stir uniformly for 5min, then add triethanolamine, continue to stir for 30min, then slowly add tetraethyl ammonium hydroxide, stir uniformly for 30min, then age at room temperature for 24h, after aging, transfer to a 100℃ oven for drying for 24h, prepare a gel, then transfer to a reaction kettle, hydrothermal treatment at 180℃ for 8h, then calcine at 550℃ for 12h, prepare a catalytic carrier, control the amount ratio of tetrabutyl titanate, tetraethyl silicate, triethanolamine and tetraethyl ammonium hydroxide to be 21.02mL:72mL:25.40mL:16.20mL;

[0027] Step S2, add the catalytic carrier to a 90% ethanol aqueous solution, add KH570, stir uniformly for 15min, then adjust the pH of the system until pH=4, then stand for 1h, warm up to 60℃, stir uniformly and react for 4h, after the reaction, prepare a modified catalytic carrier, control the amount ratio of the catalytic carrier, KH570 and the ethanol aqueous solution to be 1g:3mL:10mL;

[0028] Step S3, add polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate and the modified catalytic carrier to deionized water, ultrasonic dispersion for 30min, warm up to 40℃, add ammonium persulfate, react under nitrogen atmosphere for 20h, after the reaction, prepare a water treatment agent, control the amount ratio of polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate, modified catalytic carrier, ammonium persulfate and deionized water to be 1mmol:1mmol:0.05mmol:2g:3g:0.03mmol:20mL.

[0029] Embodiment 2: a method for advanced oxidation and digestion of wastewater containing metal-containing paint, comprising the following steps:

[0030] Step 1: adjust the pH of the wastewater containing metal-containing paint to 4.5 with a 10% mass fraction hydrochloric acid solution, then add Fenton reagent, uniformly stir and oxidize for 1.2 h, then add 10% mass fraction sodium hydroxide dropwise to adjust the system to neutral, and obtain the oxidized wastewater;

[0031] Step 2: add a water treatment agent to the oxidized wastewater, stir at a speed of 150 r / min under light for 4 min, stand for 1.2 h, sand filter, and complete the treatment.

[0032] The concentration of ferrous sulfate in the Fenton reagent in Step 1 is 1.1 g / L, and the concentration of hydrogen peroxide is 8 mL / L.

[0033] The concentration of the water treatment agent in Step 2 is 1.5 g / L.

[0034] The water treatment agent is prepared by the following steps:

[0035] Step S1: add tetrabutyl titanate to tetraethyl orthosilicate, uniformly stir for 5 min, then add triethanolamine, continue to stir for 30 min, then slowly add tetraethylammonium hydroxide, uniformly stir for 30 min, then age at room temperature for 24 h, after aging, transfer to a 100°C oven for drying for 24 h, obtain a gel, then transfer to a reaction kettle, hydrothermal treatment at 180°C for 8 h, then calcine at 600°C for 12 h, obtain a catalytic carrier, control the amount ratio of tetrabutyl titanate, tetraethyl orthosilicate, triethanolamine and tetraethylammonium hydroxide to be 21.20 mL: 78 mL: 25.45 mL: 16.40 mL;

[0036] Step S2: add the catalytic carrier to a 90% volume fraction ethanol aqueous solution, add KH570, uniformly stir for 20 min, then adjust the pH of the system until pH=4, then stand for 1 h, warm up to 65°C, uniformly stir and react for 4 h, after the reaction, obtain a modified catalytic carrier, control the amount ratio of the catalytic carrier, KH570 and the ethanol aqueous solution to be 1.5 g: 5 mL: 12 mL;

[0037] Step S3: add polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate and the modified catalytic carrier to deionized water, ultrasonic dispersion for 30 min, warm up to 44°C, add ammonium persulfate, react under nitrogen atmosphere for 22 h, after the reaction, obtain a water treatment agent, control the amount ratio of polypropylene, methacryloyloxyethyl trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate, the modified catalytic carrier, ammonium persulfate and deionized water to be 1.5 mmol: 1.5 mmol: 0.06 mmol: 2.5 g: 4 g: 0.04 mmol: 25 mL.

[0038] Embodiment 3: A method for advanced oxidation and digestion of wastewater containing metal-containing paint, comprising the following steps:

[0039] Step 1: Adjust the pH of the wastewater containing metal-containing paint to 4.5 with a 10% mass fraction hydrochloric acid solution, then add Fenton reagent, uniformly stir and oxidize for 1.5 h, then adjust the system to neutral with a 10% mass fraction sodium hydroxide solution, and obtain the oxidized wastewater;

[0040] Step 2: Add a water treatment agent to the oxidized wastewater, stir at a speed of 200 r / min under light for 5 min, stand for 1.5 h, and filter with sand, and the treatment is completed.

[0041] The concentration of ferrous sulfate in the Fenton reagent in Step 1 is 1.2 g / L, and the concentration of hydrogen peroxide is 10 mL / L.

[0042] The concentration of the water treatment agent in Step 2 is 2 g / L.

[0043] The water treatment agent is prepared by the following steps:

[0044] Step S1: Add tetrabutyl titanate to tetraethyl silicate, uniformly stir for 5 min, then add triethanolamine, continue to stir for 30 min, then slowly add tetraethyl ammonium hydroxide, uniformly stir for 30 min, then age at room temperature for 24 h, after aging, transfer to a 100°C oven and dry for 24 h, obtain a gel, then transfer to a reaction kettle, hydrothermal treatment at 180°C for 8 h, then calcine at 600°C for 12 h, obtain a catalytic carrier, control the amount ratio of tetrabutyl titanate, tetraethyl silicate, triethanolamine and tetraethyl ammonium hydroxide to be 21.28 mL: 82 mL: 25.48 mL: 16.58 mL;

[0045] Step S2: Add the catalytic carrier to a 90% volume fraction ethanol aqueous solution, add KH570, uniformly stir for 30 min, then adjust the pH of the system until pH=4, then stand for 1 h, warm up to 70°C, uniformly stir and react for 4 h, after the reaction, obtain a modified catalytic carrier, control the amount ratio of the catalytic carrier, KH570 and the ethanol aqueous solution to be 2 g: 6 mL: 15 mL;

[0046] Step S3, polypropylene, methacryloyl ethoxy trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate and modified catalytic carrier were added into deionized water, ultrasonic dispersion for 30 min, heated to 45℃, added ammonium persulfate, reacted for 24 h under nitrogen atmosphere, after reaction, water treatment agent was prepared, the amount ratio of polypropylene, methacryloyl ethoxy trimethyl ammonium chloride, polydimethyl diallyl ammonium chloride, ammonium sulfate, modified catalytic carrier, ammonium persulfate and deionized water was controlled as 2mmol:2mmol:0.08mmol:3g:5g:0.05mmol:30mL.

[0047] Comparative Example 1: Compared with Example 1, no water treatment agent was added, and the rest was the same as Example 1.

[0048] The standard wastewater was treated according to the treatment method disclosed in Examples 1-3 and Comparative Example 1, and the results of the treated wastewater are shown in Table 1 below:

[0049] Table 1

[0050]

[0051] From Table 1 above, it can be seen that Examples 1-3 of the present application have excellent purification treatment effect on wastewater.

[0052] The above is only an example and description of the concept of the present application, and those skilled in the art can make various modifications or supplements to the described specific examples or use similar ways to replace, as long as they do not deviate from the concept of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A method for deep oxidation and digestion of wastewater containing metallic paint, characterized in that: The steps include: Step 1: Use 10% hydrochloric acid solution to adjust the pH of the wastewater containing metallic paint to 4-4.5, then add Fenton reagent, stir at a constant speed and oxidize for 1-1.5 hours, then add 10% sodium hydroxide dropwise to adjust the system to neutrality to obtain oxidized wastewater; The second step is to add water treatment agent to the oxidized wastewater, stir at 100-200 r / min for 3-5 minutes under light, let it settle for 1-1.5 hours, and sand filter to complete the treatment; The water treatment agent is prepared by the following steps: Step S1, adding tetrabutyl titanate to tetraethyl silicate, stirring at a uniform speed for 5 minutes, then adding triethanolamine, continuing to stir for 30 minutes, then slowly adding tetraethylammonium hydroxide dropwise, stirring at a uniform speed for 30 minutes, then aging at room temperature for 24 hours, transferring to a 100°C oven after aging and drying for 24 hours to obtain a gel, then transferring to a reactor, hydroheating at 180°C for 8 hours, and then calcining at 550-600°C for 12 hours to obtain a catalytic support, wherein the amount ratio of tetrabutyl titanate, tetraethyl silicate, triethanolamine and tetraethylammonium hydroxide is controlled to be 21.02-21.28 mL: 72-82 mL: 25.40-25.48 mL: 16.20-16.58 mL; Step S2, adding the catalyst support to a 90% by volume ethanol aqueous solution, adding KH570, stirring at a constant speed for 15-30 minutes, then adjusting the pH of the system, then standing for 1 hour, heating to 60-70° C., stirring at a constant speed and reacting for 4 hours. After the reaction is completed, a modified catalyst support is obtained, and the amount ratio of the catalyst support, KH570 and ethanol aqueous solution is controlled to be 1-2 g: 3-6 mL: 10-15 mL; Step S3, adding polypropylene, methacryloylethoxytrimethylammonium chloride, polydimethyldiallyl ammonium chloride, ammonium sulfate and a modified catalyst support to deionized water, ultrasonically dispersing for 30 minutes, heating to 40-45° C., adding ammonium persulfate, and reacting under a nitrogen atmosphere for 20-24 hours. After the reaction, a water treatment agent is obtained, and the amount ratio of polypropylene, methacryloylethoxytrimethylammonium chloride, polydimethyldiallyl ammonium chloride, ammonium sulfate, modified catalyst support, ammonium persulfate and deionized water is controlled to be 1-2 mmol: 1-2 mmol: 0.05-0.08 mmol: 2-3 g: 3-5 g: 0.03-0.05 mmol: 20-30 mL.

2. The method for deep oxidation and digestion of wastewater containing metallic paint according to claim 1, characterized in that: In the first step, the concentration of ferrous sulfate in the Fenton reagent is 1-1.2 g / L, and the concentration of hydrogen peroxide is 5-10 mL / L.

3. The method for deep oxidation and digestion of wastewater containing metallic paint according to claim 1, characterized in that: The concentration of the water treatment agent in the second step is 1-2 g / L.

4. The method for deep oxidation and digestion of wastewater containing metallic paint according to claim 1, characterized in that: In step S2, the system pH=4.

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