CN102976475B - Ozonization water treatment method by taking fluorine-doped manganese dioxide nano composite material as catalyst - Google Patents

Abstract

The present invention proposes an ozonated water treatment method using fluorine-doped manganese dioxide nanocomposite material as a catalyst, adding the prepared fluorine-doped manganese dioxide nanocomposite material as a catalyst in wastewater containing phenolic organic matter In order to promote the degradation of phenolic organic pollutants by ozone, and on this basis, a new ozonated water treatment method was proposed. The method belongs to the technical field of water treatment and environmental catalysis. The obtained fluorine-doped manganese dioxide nano-nanocomposite material introduces the non-metallic element fluorine, and has the characteristics of easy operation of synthesis steps, small scale, good dispersion in aqueous solution system, and easier recovery. It has great potential in ozonated water treatment applications. Broad prospects.

Description

Ozonation water treatment method using fluorine-doped manganese dioxide nanocomposite as catalyst

technical field

The invention proposes an ozonated water treatment method using a fluorine-doped manganese dioxide nanocomposite material as a catalyst to reduce water pollution, and belongs to the field of environmental catalysis and water treatment. the

Background technique

At present, the industry continues to progress, but inevitably produces a lot of pollution. As an important industrial raw material widely used in the fields of drugs, dyes, fibers, phenolic resin synthesis, and medical disinfectants, the usage of phenol at home and abroad has been on the rise. Phenol is considered a highly toxic substance due to its inhibitory ability to the central nervous system and damage to kidney function. Due to the structural problems of phenol, the phenolic substances in the wastewater discharged from various factories are extremely difficult to degrade naturally. Ozone itself has a certain oxidation ability and is easy to decompose. It is an ideal oxidant for degrading various organic compounds. However, due to the slow reaction rate, narrow degradation range, and low mineralization rate of ozone oxidation alone, the catalytic ozonation reaction with catalyst added in the ozone oxidation process has its unique application prospects. the

The catalytic ozonation reaction is an advanced oxidation reaction, which is an improvement and enhancement of the traditional non-catalytic ozonation reaction. Through the action of catalyst, it improves the ability of ozone oxidation, so that organic matter can be degraded and mineralized in a short period of time. In the process of catalytic ozone oxidation degradation, the catalyst plays two roles: one is to increase the reactivity and utilization rate of ozone; the other is to increase the degradation rate and mineralization degree of organic matter. Compared with the homogeneous catalytic ozonation reaction, the heterogeneous catalytic ozonation reaction has the advantages of high ozone decomposition rate, easy recovery and reuse of the catalyst, and no secondary pollution. It has been widely recognized in the increasingly stringent environmental protection treatment . the

Contents of the invention

The purpose of the present invention is to provide a high-efficiency nanocomposite material, and provide its use method in ozonated water treatment, and then improve the practical application value of catalytic ozonation in the field of water treatment. The purpose of the present invention can be achieved through the following technical solutions:

(1) Preparation of fluorine-doped manganese dioxide nanocomposites: 9mmol KMnO ₄ and 6mmol MnCl ₂ .4H ₂ O were dissolved in 80mL and 20mL water respectively, and then MnCl ₂ was added dropwise at a rate of 2.4mL/min to KMnO ₄ solution, stirred for one hour, at this time, 10 mL of NH ₄ F solutions of different concentrations were added dropwise to the reaction solution at a rate of 2.0 mL/min, and after stirring for one hour, the reaction solution was transferred to the hydrothermal reaction kettle and reacted at 160°C for 6h, the obtained product was washed to neutral, and dried at 80°C for 18h to obtain the final nanocomposite material;

(2) Ozonated water treatment: Add the obtained nano-composite material into the waste water, pass ozone under stirring, and catalyze and oxidize and degrade organic pollutants. the

During the experiment, the concentration of the NH ₄ F solution used in the preparation of the composite material was 0.2-0.8mol.L ^-1 , the ratio of the mass of the added catalyst to the mass of the treated wastewater was 1:1000, and the reaction temperature was 25°C A better catalytic effect can be achieved.

Salient features of the present invention:

(1) The fluorine-doped manganese dioxide nanocomposite material introduces non-metallic elements, which significantly improves the degradation of phenol-containing wastewater by nanocomposite material in ozone. In addition to its catalytic effect originating from the manganese dioxide phase in the nanocomposite material, the doped fluorine element also effectively promotes the interaction between the nanocomposite material and ozone, and finally obtains a better catalytic effect. the

(2) The fluorine-doped manganese dioxide nanocomposite has a small size and is easy to disperse in water, which increases the contact area between the nanocomposite and ozone and phenol pollutants, and maximizes the use of pollutants to degrade them. . the

(3) The synthesis process of fluorine-doped manganese dioxide nanocomposites is simple and environmentally friendly, there is no secondary pollution during the synthesis process, and it can be recycled and reused through simple sedimentation, which provides an important guarantee for its practical application. the

Description of drawings

Among Fig. 1 (a), (b), (c), (d) are the SEM photo of embodiment 1,2,3,4 obtained product respectively;

Among Fig. 2, a, b, c, d are the XRD collection of illustrative plates of embodiment 1,2,3,4 obtained products respectively;

Fig. 3 is the concentration variation curve of phenol with ozonation time in embodiment 6, a line is ozonation alone (without catalyst), b line is nanomaterial catalyzed ozonation in embodiment 1, and c line is nanomaterial in embodiment 2 Catalytic ozonation, d line is the catalytic ozonation of nanomaterials in embodiment 3, and e line is the catalytic ozonation of nanomaterials in embodiment 4,

Detailed ways

In order to describe the method of the present invention more specifically, the following examples of the present invention are given, but the application of the present invention is not limited thereto. the

Example 1

Weigh 9mmol KMnO ₄ , dissolve it in 80mL water, and stir it evenly with a magnetic stirrer. Weigh 6 mmol of MnCl ₂ .4H ₂ O and dissolve it in 20 mL of water, and then add it dropwise at a rate of 2.4 mL/min to the previously dissolved and stirred KMnO ₄ solution. After the dropwise addition, continue to stir for 1 h, and then add 15 mL of 0.2 mol.L ^-1 NH ₄ F solution prepared in advance at a rate of 2.0 ml/min to the aforementioned solution that has been reacted for 1 h. After all the NH ₄ F solution was added dropwise, the reaction solution was transferred to a 120 mL hydrothermal reactor and reacted at 160° C. for 6 h after continuing to stir at the same rate for 1 h. After the completion of the hydrothermal reaction, the reactor was naturally cooled to room temperature, and the obtained product was washed to neutrality, and dried at 80° C. for 18 hours to obtain the final nanomaterial.

Example 2

Weigh 9mmol KMnO ₄ , dissolve it in 80mL water, and stir it evenly with a magnetic stirrer. Weigh 6 mmol of MnCl ₂ ·4H ₂ O and dissolve it in 20 mL of water, and then add it dropwise at a rate of 2.4 mL/min to the previously dissolved and stirred KMnO ₄ solution. After the dropwise addition was completed, the stirring was continued for 1 h, and then 15 mL of 0.4 mol·L ^-1 NH ₄ F solution prepared in advance was added dropwise at a rate of 2.0 mL/min to the aforementioned solution that had been reacted for 1 h. After all the NH ₄ F solution was added dropwise, the reaction solution was transferred to a 120 mL hydrothermal reactor and reacted at 160° C. for 6 h after continuing to stir at the same rate for 1 h. After the completion of the hydrothermal reaction, the reactor was naturally cooled to room temperature, and the obtained product was washed to neutrality, and dried at 80° C. for 18 hours to obtain the final nanomaterial.

Example 3

Weigh 9mmol KMnO ₄ , dissolve it in 80mL water, and stir it evenly with a magnetic stirrer. Weigh 6 mmol of MnCl ₂ ·4H ₂ O and dissolve it in 20 mL of water, and then add it dropwise at a rate of 2.4 mL/min to the previously dissolved and stirred KMnO ₄ solution. After the dropwise addition was completed, the stirring was continued for 1 h, and then 15 mL of 0.6 mol·L ^-1 NH ₄ F solution that had been prepared in advance was added dropwise at a rate of 2.0 mL/min to the aforementioned solution that had been reacted for 1 h. After all the NH ₄ F solution was added dropwise, the reaction solution was transferred to a 120 mL hydrothermal reactor and reacted at 160° C. for 6 h after continuing to stir at the same rate for 1 h. After the completion of the hydrothermal reaction, the reactor was naturally cooled to room temperature, and the obtained product was washed to neutrality, and dried at 80° C. for 18 hours to obtain the final nanomaterial.

Example 4

Weigh 9mmol KMnO ₄ , dissolve it in 80mL water, and stir it evenly with a magnetic stirrer. Weigh 6 mmol of MnCl ₂ ·4H ₂ O and dissolve it in 20 mL of water, and then add it dropwise at a rate of 2.4 mL/min to the previously dissolved and stirred KMnO ₄ solution. After the dropwise addition was completed, the stirring was continued for 1 h, and then 15 mL of 0.8 mol·L ^-1 NH ₄ F solution prepared in advance was added dropwise at a rate of 2.0 mL/min to the aforementioned solution that had been reacted for 1 h. After all the NH ₄ F solution was added dropwise, the reaction solution was transferred to a 120 mL hydrothermal reactor and reacted at 160° C. for 6 h after continuing to stir at the same rate for 1 h. After the completion of the hydrothermal reaction, the reactor was naturally cooled to room temperature, and the obtained product was washed to neutrality, and dried at 80° C. for 18 hours to obtain the final nanomaterial.

Example 5

Measure 200 mL of simulated wastewater with a phenol content of 300 mg L ^-1 , add 0.20 g of the nanocomposite material obtained in the above example, and stir at a constant speed for 10 minutes using a magnetic stirrer, then inject ozone at a flow rate of 21 mL/min at 25 °C. Samples were taken at equal intervals to test the concentration of phenol. The result is shown in Figure 3. It shows that the nanocomposite material of the present invention has significant catalytic effect on wastewater containing phenols.

Claims (2)

1. the ozonization water treatment method take the manganese dioxide nano-composite material of doped with fluorine as catalyzer, is characterized in that adopting the nano material of nonmetal doping as catalyzer, and concrete steps are as follows:

(1) preparation of the manganese dioxide nano-composite material of doped with fluorine: by 9mmolKMnO ₄and 6mmolMnCl ₂.4H ₂o is dissolved in respectively in 80mL, 20mL water, under the condition of magnetic agitation, by MnCl ₂the aqueous solution be dropwise added drop-wise to KMnO with the speed of 2.4mL/min ₄in solution, continue after one hour, in reaction solution, to add the certain density NH of 15mL with the speed of 2.0mL/min with constant speed stirring reaction liquid ₄f solution, then transfers to reaction solution in the hydrothermal reaction kettle of 120mL, and reacts 6h at 160 ℃, after reaction finishes, reactor is naturally cooled to room temperature, and the product water obtaining is washed till neutrality, and 80 ℃ of dry 18h, obtain final nano composite material;

(2) ozonization water treatment: synthetic nano composite material is joined in waste water, pass into ozone under stirring, catalyzing oxidizing degrading organic pollutant.

2. the manganese dioxide nano-composite material take doped with fluorine according to claim 1 is the ozonization water treatment method of catalyzer, NH used in its matrix material preparation ₄the concentration of F solution is 0.2-0.8mol.L ^-1.

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