阅读说明：本技术 基于六方水钠锰矿的去除有机染料的方法、结合物和装置 (Method, combination and device for removing organic dye based on birnessite ) 是由 程晓迪 严格 张嵚 秦张杰 兰帅 于 2020-07-01 设计创作，主要内容包括：本发明涉及污水处理领域,特别是涉及一种基于六方水钠锰矿的去除有机染料的方法、结合物和装置。所述方法为将自由基供体和六方水钠锰矿溶液添加至有机染料溶液中,为反应混合液,反应混合液在室温条件下混合均匀,反应0.5～6小时；六方水钠锰矿溶液作为催化剂,催化自由基供体产生自由基,自由基氧化有机染料溶液的有机染料,六方水钠锰矿吸附和氧化有机染料。所述结合物为在六方水钠锰矿上结合有自由基。所述装置包括流通管道,在液体入口处设有自由基管,在流通管道中设有网状结构体,网状结构体内设有六方水钠锰矿颗粒。本发明能够去除有机染料中的亚甲基蓝和酸性红1288,本发明能够在中酸性或弱酸性条件下快速氧化、降解带负电荷的有机染料。(The invention relates to the field of sewage treatment, in particular to a method, a combination and a device for removing organic dye based on birnessite. Adding a free radical donor and a hexagonal birnessite solution into an organic dye solution to obtain a reaction mixed solution, and uniformly mixing the reaction mixed solution at room temperature for 0.5-6 hours; the solution of the hexagonal birnessite is used as a catalyst to catalyze the free radical donor to generate free radicals, the free radicals oxidize the organic dye of the organic dye solution, and the hexagonal birnessite adsorbs and oxidizes the organic dye. The combination is formed by combining free radicals on the hexagonal birnessite. The device comprises a circulation pipeline, a free base pipe is arranged at a liquid inlet, a net-shaped structure body is arranged in the circulation pipeline, and hexagonal birnessite particles are arranged in the net-shaped structure body. The organic dye can remove methylene blue and acid red 1288 in the organic dye, and can rapidly oxidize and degrade the organic dye with negative charges under the condition of medium acidity or weak acidity.)

1. The method for removing the organic dye based on the hexagonal birnessite is characterized in that a free radical donor and a hexagonal birnessite solution are added into an organic dye solution to form a reaction mixed solution, and the reaction mixed solution is uniformly mixed at room temperature and reacts for 0.5-6 hours;

wherein: the solution of the hexagonal birnessite is used as a catalyst to catalyze a free radical donor to generate free radicals, the free radicals oxidize the organic dye in the solution of the organic dye, and the hexagonal birnessite in the solution of the hexagonal birnessite adsorbs and oxidizes the organic dye.

2. The method of claim 1,

the concentration of the birnessite in the reaction mixed solution is 50-400 mg/L.

3. The method of claim 1,

the free radical donor is hydrogen peroxide, the free radical is a hydroxyl free radical, and the concentration of the hydrogen peroxide in the reaction mixed solution is 19-150 mmol/L; or (b).

The free radical donor is persulfate, the free radical is sulfate radical, and the concentration of the persulfate in the reaction mixed solution is 1-8 mmol/L.

4. The method of claim 3,

the persulfate is sodium persulfate.

5. The method of claim 1,

the pH value of the solution of the hexagonal birnessite is 2-8; the pH value of the organic dye solution is 2-8.

6. The method of claim 1,

the pH value of the solution of the hexagonal birnessite is 4-5.3; the pH value of the organic dye solution is 4-5.3.

7. The method of claim 1,

the organic dye with negative charges is acid red 1288, and the concentration of the acid red 1288 in the reaction mixed liquid is 20-160 mu mol/L.

8. A combination for removing organic dye based on birnessite is characterized in that,

the conjugate is formed by combining free radicals on the birnessite, wherein the free radicals are used for oxidizing organic dyes, the birnessite is used for adsorbing and oxidizing the organic dyes, and the free radicals are hydroxyl free radicals or sulfate free radicals.

9. A device for removing organic dye based on hexagonal birnessite, comprising:

the flow pipeline comprises a liquid inlet and a liquid outlet, the organic dye solution to be repaired flows into the flow pipeline from the liquid inlet, and the repaired organic dye solution flows out from the liquid outlet;

the free radical adding pipe is connected to the liquid inlet and is used for adding a free radical donor into the organic dye solution to be repaired;

and the net-shaped structure body is arranged between the free radical adding pipe and the liquid outlet, and hexagonal birnessite particles are arranged in the net-shaped structure body.

10. The apparatus of claim 9,

the circulation pipeline is an S-shaped pipeline;

the net-shaped structure body comprises a first surface and a second surface, the second surface is arranged between the first surface and the liquid outlet, the mesh number of the net-shaped structure of the second surface is 500-1000, and the particle size of the hexagonal birnessite particles is 100-150 mu m.

Technical Field

The invention relates to the field of sewage treatment, in particular to a method and a combination for removing organic dye based on birnessite.

Background

The chemical method is an important method for removing printing and dyeing wastewater and mainly comprises a common chemical oxidation method, a Fenton method, a photocatalytic oxidation method, an electrochemical method and the like. The common chemical oxidation method mainly uses ozone, chlorine and oxides thereof to destroy chromophoric groups of the dye to achieve the effect of decoloring. Ozone is a strong oxidant, can form hydroxyl radical OH in aqueous solution, and reacts with dye to break unsaturated bonds in chromophoric group of the ozone to generate colorless organic acid, aldehyde and the like with small molecular weight, thereby achieving the purposes of decolorization and degradation. The Fenton process is a common advanced oxidation process, primarily by H₂O₂And Fe²⁺Mixed into a strong oxidant, can generate hydroxyl free radicals OH with strong oxidizing capability, thereby achieving the purpose of treating the organic wastewater difficult to biodegrade. The Fenton method is often used as pretreatment of wastewater treatment and final advanced treatment of wastewater treatment due to the advantages of simple reaction conditions, simple equipment, no secondary pollutants and the like, but has higher treatment cost, and H₂O₂Easy decomposition is also a disadvantage of the Fenton process. Photocatalytic oxidation from TiO₂The research of (1) utilizes photosensitive semiconductor material to generate hydroxyl free radical OH under the action of illumination, oxidizes organic matters in wastewater and converts the organic matters into CO₂And H₂And O and other inorganic small molecules. TiO 2₂As a semiconductor catalyst which has high chemical stability, strong oxidability, capability of absorbing partial ultraviolet radiation in sunlight, acid and alkali corrosion resistance and no toxicity, the catalyst can also thoroughly degrade dyes, has no secondary pollution, high efficiency and environmental protection, and is most popular and most effective at present. The last electrochemical method is also an effective method for treating printing and dyeing wastewater. The electrochemical method is mainly characterized in that organic matters in the printing and dyeing wastewater are subjected to electric flocculation and electricity on positive and negative electrodes such as iron plates, graphite, aluminum plates and the likeThe chromophoric group of the dye molecule is destroyed by the action of flotation, electrolytic oxidation-reduction and the like to decolor. The electrochemical method for degrading the printing and dyeing wastewater has the advantages of simple operation, good removal effect, no need of adding other substances in the removal process, and the defects of large energy consumption, high cost and lack of practicability in the application of actual printing and dyeing wastewater treatment.

Disclosure of Invention

In view of the above, the present invention provides a method for removing an organic dye based on a birnessite, and mainly aims to provide a method for removing an organic dye based on a birnessite, so as to improve the stability of a reaction process and rapidly degrade the organic dye in an adsorption and oxidation manner.

In order to achieve the purpose, the invention mainly provides the following technical scheme:

the method for removing the organic dye based on the hexagonal birnessite comprises the steps of adding a free radical donor and a hexagonal birnessite solution into an organic dye solution to obtain a reaction mixed solution, uniformly mixing the reaction mixed solution at room temperature, and reacting for 0.5-6 hours;

wherein: the solution of the hexagonal birnessite is used as a catalyst to catalyze a free radical donor to generate free radicals, the free radicals oxidize the organic dye in the solution of the organic dye, and the hexagonal birnessite in the solution of the hexagonal birnessite adsorbs and oxidizes the organic dye.

Preferably, the concentration of the birnessite in the reaction mixed solution is 50-400 mg/L.

Preferably, the free radical donor is hydrogen peroxide, the free radical is a hydroxyl free radical, and the concentration of the hydrogen peroxide in the reaction mixed solution is 19-150 mmol/L.

Preferably, the free radical donor is persulfate, the free radical is a sulfate radical, and the concentration of the persulfate in the reaction mixed solution is 1-8 mmol/L.

Preferably, the persulfate is sodium persulfate.

Preferably, the pH value of the solution of the birnessite is 2-8; the pH value of the organic dye solution is 2-8.

Preferably, the pH value of the solution of the birnessite is 4-5.3; the pH value of the organic dye solution is 4-5.3.

Preferably, the organic dye is a negatively charged organic dye that is acid red 1288.

Preferably, the concentration of the acid red 1288 in the reaction mixed liquid is 20-160 mu mol/L.

A combination of a birnessite having radicals bound thereto, the radicals being for oxidising an organic dye, the birnessite being for adsorbing and oxidising the organic dye.

A device for removing organic dye based on hexagonal birnessite comprises: the flow pipeline comprises a liquid inlet and a liquid outlet, the organic dye solution to be repaired flows into the flow pipeline from the liquid inlet, and the repaired organic dye solution flows out from the liquid outlet; a free radical addition pipe, the free base pipe being connected at the liquid inlet; and the net-shaped structure body is arranged between the free radical adding pipe and the liquid outlet, and the hexagonal birnessite is arranged in the net-shaped structure body. The pipeline between the free radical adding pipe and the net-shaped structure body is an S-shaped bend; the reticular structure body comprises a first surface and a second surface, the second surface is arranged between the first surface and the liquid outlet, and the mesh number of the reticular structure of the second surface is 500-1000.

By means of the technical scheme, the method for removing the organic dye based on the birnessite at least has the following advantages:

1) generating free radicals through a free radical donor, and oxidizing organic dyes by the free radicals, wherein the organic dyes are adsorbed and oxidized by the hexagonal birnessite in the hexagonal birnessite solution, and are positively charged methylene blue and negatively charged acid red 1288;

2) the method can rapidly oxidize and degrade negatively charged organic dye acid 1288 under the condition of medium acidity or weak acidity;

3) the method has short reaction time and simple reaction conditions.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a standard curve of MB dye;

FIG. 2 is a standard curve for AR88 dye;

FIG. 3-1 is an XRD spectrum of a hexagonal birnessite;

3-2 is an FTIR spectrum of a birnessite hexagonal;

3-3 are SEM images of a birnessite hexagonal;

3-4 are TEM images of hexagonal birnessite;

fig. 3-5 are wavelength scans (d) of visible light using a pseudo-first order (b), a pseudo-second order (c) to simulate adsorption reaction curves and MB dye as a function of reaction time;

fig. 3-6 are comparisons of removal of MB dye by birnessite at different pH (pH 2.00, 4.01, 5.92, 8.05);

FIGS. 3-7 are Rads and Roxi for birnessite to MB at pH 2.00(a), 4.01(b), 5.92(c) and 8.05(d) at 0.5h, 1h and 3 h;

FIGS. 3 to 8 show the trend of pH change during the reaction;

FIGS. 3 to 9 show Mn in the course of the reaction²⁺The trend of change of (c);

FIGS. 3-10 are UV-Vis spectra of MB after 3 hours of reaction at different pH conditions;

FIGS. 3-11 are FTIR spectra of minerals before and after 3 hours of reaction with MB at different pH conditions;

fig. 3-12 are XPS N1s spectra and best fit (pH 2.00, pH 4.01, pH 5.92, pH 8.05) before and after reaction of birnessite with MB at different pH;

FIGS. 3-13 are wavelength scans (d) of visible light using a pseudo first order (b), a pseudo second order (c) to simulate an adsorption reaction curve and acid red 88 dye as a function of reaction time;

figures 3-14 are comparisons of the removal of acid red 88 dye by birnessite at different pH ( pH 2, 4, 5, 8);

FIGS. 3-15 are Rads and Roxi of birnessite versus acid Red 88 at pH 2(a), 4(b), 5(c), and 8(d) at 0.5h, 1h, and 3 h;

FIGS. 3-16 are graphs showing the change in solution pH during removal of acid red 88 from birnessite at various pH's;

FIGS. 3-17 are UV-Vis spectra of AR88 after 3 hours of reaction at different pH conditions;

FIGS. 3-18 are FTIR spectra of minerals before and after 3 hours of reaction with acid Red 88 at various pH conditions;

FIGS. 3-19 are the best fit Mn 2p from XPS after reaction of birnessite with AR88 at different pH conditions (2(b), 4(c), 6(d), 8 (e));

FIGS. 3-20 show the addition of H to birnessite at different pH values₂O₂The system compares the removal effect of AR 88;

FIGS. 3-21 show birnessite and H at different AR88 concentrations₂O₂The mixed system is used for comparing the removal effect of AR 88;

FIGS. 3-22 show birnessite and H at different mineral concentrations₂O₂The mixed system is used for comparing the removal effect of AR 88;

FIGS. 3-23 are different H₂O₂Under the concentration condition, the hexagonal birnessite and H₂O₂Comparison of AR88 removal effects of the mixed system

FIGS. 3-24 are graphs showing the effect of a mixed system of birnessite and PS on the removal of AR88 under different pH conditions

FIGS. 3-25 are graphs showing the effect of a mixed system of birnessite and PS on the removal of AR88 under different dye concentrations

FIGS. 3-26 are graphs showing the comparison of the effect of a mixed system of birnessite and PS on the removal of AR88 under different mineral concentrations

Fig. 3-27 are graphs comparing the removal of AR88 by the mixed system of birnessite and PS at different PS concentrations.

Detailed Description

The deionized water used in the experiments of the examples of the present invention was prepared by an ultrapure water system instrument (Upu ultrapure water machine UPT-II-10T), and the conductivity was less than 2.0. mu.S/cm. The reagents used in the experiment were analytical pure (AR) reagents. The main chemical reagents used in the experiment are shown in table 1, and the main instruments are shown in table 2.

The invention discloses a method for removing organic dye based on hexagonal birnessite, which comprises the steps of adding a free radical donor and a hexagonal birnessite solution into an organic dye solution to obtain a reaction mixed solution, uniformly mixing the reaction mixed solution at room temperature, and reacting for 0.5-6 hours;

wherein: the solution of the hexagonal birnessite is used as a catalyst to catalyze a free radical donor to generate free radicals, the free radicals oxidize the organic dye in the solution of the organic dye, and the hexagonal birnessite in the solution of the hexagonal birnessite adsorbs and oxidizes the organic dye. The organic dyes used in the present invention represent the cationic dyes Methylene Blue (MB) with a positive charge and the anionic dye acid red 88(AR88) with a negative charge, respectively.

Birnessite (Birnessite) is one of the most widely distributed manganese oxide minerals in soil, a common and more studied manganese oxide with a layered structure consisting of [ MnO ]₆]The octahedron is connected into a layered structure along the common edges, and if the center of the octahedron is deleted, an octahedron vacancy is formed. Or the existence of octahedral vacancy makes the water sodium manganese ore manganese oxygen octahedral layer carry a large amount of negative charges, and the negative charges of the layer are formed by Mn^2+/3+，H⁺， K⁺Or Na⁺Equilibria, a layer of water molecules exists between the layers. The acid and alkaline birnessite can be divided into acid birnessite and alkaline birnessite according to the environment formed by the acid and alkaline birnessite. The acid birnessite is weak in crystallization, small in crystal grain and in a hexagonal symmetrical configuration, the crystal morphology is fine needle spherical crystallization which is close to that of natural birnessite, the alkaline birnessite is better in crystallization and in a triclinic symmetrical structure, and the crystal morphology is generally hexagonal flaky or platy crystallization. Wherein sodium manganese triclinicWhen the ore is balanced under an acid condition, the ore can be converted into birnessite with hexagonal symmetry: first, the interlayer Na of the triclinic birnessite⁺Same as H⁺Rapid exchange occurs while Mn in the layer³⁺Disproportionation reaction to produce Mn²⁺And Mn⁴⁺，Mn²⁺Migrating into the solution to form vacancies; mn in partial layer³⁺Or can migrate into the interlaminar region and adsorb onto the octahedral vacancies above and below. The hexagonal birnessite is a mineral with large specific surface, low charge zero point, high cation exchange capacity and strong oxidation capacity. Can effectively oxidize and degrade organic matters such as phenols, aniline, organic dyes and the like.

In the invention, the hexagonal birnessite is prepared by the following method: KMnO for hexagonal birnessite₄And HCl preparation. 300-400mL of 0.4mol/L was placed in a 500mL Erlenmeyer flask, then boiled in a room temperature oil bath (110 ℃ C.), 120mL of 6mol/L HCl was added dropwise at a rate of 0.7mL/min under vigorous stirring, after which the reaction was continued for 30 minutes and the resulting product was aged at 60 ℃ for 12 hours. Conductivity after washing with deionized water<15 μ s/cm. The final product was dried in an oven at 40 ℃, ground and passed through a 60 mesh screen, and then placed in a desiccator for later use.

In the invention, the organic dye removal rate calculation mode is as follows: preparing 100mL of 400mg/L hexagonal birnessite suspension, placing the suspension on a magnetic stirrer, stirring stably, adjusting the pH to 3.99 by using 0.1mol/LHCL and 0.1mol/LNaOH, and balancing for a plurality of days until the pH value changes to be less than or equal to +/-0.05 within 24 hours. Preparing 100mL of 160 mu mol/L organic dye (MB/AR88), adjusting the pH value to the same value, mixing and stirring the organic dye and the mineral suspension, sampling 10mL of the supernatant with a syringe along with the reaction, immediately filtering the supernatant through a 0.45 mu m membrane filter within 0min, 1min, 3min, 5min, 9min, 15min, 20min, 30min, 60min, 90min, 180min and 240min, filtering manganese oxide ore, scanning the filtrate in a full-wave band by using an ultraviolet spectrophotometer, searching absorption peaks of the dye, wherein the absorption peaks of MB and AR88 are respectively 506nm, further converting the absorption peaks into concentrations, and calculating the removal rate, wherein the formula is as follows (1) (664) (2):

wherein, C₀(μmol/L)，C_t(. mu. mol/L) and C_e(. mu. mol/L) are the initial concentration, the dye concentration at contact time (t) and the dye concentration at equilibrium, respectively.

Conversion of dye concentration: a standard curve of absorbance and molar concentration of the organic dye was prepared, wherein the concentration of MB was 0, 2, 4, 6, 8, 10, 12. mu. mol/L, the concentration of AR88 was set to 0, 5, 10, 20, 40, 80. mu. mol/L, the absorbance thereof was measured at the maximum absorption wavelength thereof, the maximum absorption peak of MB was 664nm, and that of AR88 was 506nm, and the standard curve was fitted by plotting the dye concentration against the absorbance (as shown in FIGS. 1 and 2).

The removal rate of the organic dye is further illustrated by the following examples, and Table 3 shows specific examples.