CN103586083A - Preparation method of nonhomogeneous Fenton reagent - Google Patents

Abstract

The invention discloses a preparation method of heterogeneous Fenton's reagent, which comprises the following steps: a. placing the carrier fiber in a metal salt solution in a water bath at 40-90°C; b. adding alkali to adjust the pH to alkaline to generate hydroxide , washing, and suction filtration; c, the filtered solid is placed in an oven and heated for 2-12h, and cooled to room temperature to obtain the required heterogeneous Fenton reagent. The Fenton reagent prepared by the present invention is directly used in dye solution In the photodegradation experiment, the problems of the traditional Fenton reagent, large dosage of reagent, difficult recovery and separation, loss of active components and serious secondary pollution were successfully solved. It is suitable for mass production and has wide application prospects.

Description

A kind of preparation method of heterogeneous phase Fenton's reagent

Technical field:

The invention belongs to the technical field of composite material preparation, in particular to a preparation method of heterogeneous Fenton reagent.

Background technique:

As an advanced chemical oxidation technology, the Fenton reaction essentially uses the Fenton reagent composed of Fe ²⁺ and H ₂ O ₂ to oxidize and degrade organic matter in wastewater through the HO with strong oxidizing properties produced by the reaction. Because it can efficiently treat various high-concentration and refractory organic wastewater, it has become an increasingly important method for environmental water treatment. However, the traditional homogeneous Fenton method has unavoidable shortcomings: first, the amount of reagent input is large, and iron sludge is formed after the incomplete reaction of Fe ²⁺ after the reaction, which not only wastes a lot of chemicals but also causes secondary pollution after the reaction ; Second, the reaction needs to be carried out under acidic conditions, which not only increases the reaction process but also corrodes the reaction equipment to a certain extent; third, it is difficult to recover the catalyst under the homogeneous Fenton method. In order to overcome these shortcomings, the existing technology has improved the traditional Fenton method. At present, the most researched method is based on the homogeneous Fenton method, using the principle of physical adsorption to immobilize the active components, but in the reaction still needs Only by adding acid to adjust the pH can the reaction system have a greater degradation effect, which will seriously corrode the equipment and cause serious secondary pollution. In particular, the problem of loss of catalytically active components still exists.

Invention content:

In order to solve the loss of catalytically active components and acid solution corrosion equipment, the present invention specifically proposes a preparation method of a heterogeneous Fenton reagent. The carrier fiber with coordination function is immersed in the metal salt solution, and the metal oxide is deposited on the surface of the fiber by the coordination precipitation method to form a heterogeneous Fenton reagent. The preparation method is simple and suitable for large-scale production.

A kind of preparation method of the heterogeneous Fenton's reagent provided by the invention comprises the following steps:

Step 1, placing the carrier fiber in a metal salt solution in a water bath at 40-90°C to obtain a metal ion-loaded fiber;

Step 2, adding lye to adjust the pH to alkaline, generating hydroxide, washing, and suction filtration to obtain metal hydroxide-loaded fibers;

Step 3: Heat the filtered solid in an oven for 2-12 h, and cool to room temperature to obtain metal oxide-loaded fibers, namely heterogeneous Fenton reagent.

The carrier fiber is an acrylic chelate fiber with strong coordination ability.

The metal salt solution is an aqueous solution containing any one of Fe ³⁺ and Cu ²⁺ metal ions with a concentration of 0.05-0.11 mol/L.

Described lye can be sodium hydroxide, potassium hydroxide, any one in ammoniacal liquor.

Described metal hydroxide is iron hydroxide, any one of copper hydroxide.

The metal oxide is any one of iron oxide and copper oxide.

The acrylic chelating fiber loads nanometer metal oxides with catalytic function on the surface of the fiber. The nanostructured catalyst exhibits greater catalytic activity due to its larger specific surface area; it is combined with the carrier fiber in a coordinated manner, and the combination is firm, which effectively prevents the loss of the catalyst with the water body and is also convenient for recycling. The acrylic chelate fiber with coordination function is used as a carrier, which is cheap and easy to obtain, stable in nature, non-toxic and harmless, can be reused many times, saves energy, and does not produce secondary pollution.

The prepared heterogeneous Fenton reagent is used in the photo-Fenton catalytic degradation experiment of dyes. The specific steps are: in the photocatalytic reaction apparatus, the prepared heterogeneous Fenton reagent is added to the mixed solution of dye and H ₂ O ₂ In the photo-Fenton reaction, the degradation rate is calculated by comparing the change of the absorbance of the dye before and after the reaction to judge the activity of the catalyst and the degree of degradation of the dye.

The heterogeneous Fenton reagent prepared by this method, the photocatalytic degradation research of 50 mg/L reactive red, reactive yellow, and methyl orange three dyes showed that under neutral conditions, no acid solution was needed to adjust the pH The reaction can be carried out immediately, the operation is simpler, the corrosion to the equipment is reduced, and the degradation rate of the three water-soluble dyes can reach more than 98%; the heterogeneous Fenton can realize the recovery of the catalyst through simple filtration, It can be reused many times, effectively preventing the loss of catalyst active components, and realizing the green and efficient degradation of dye solution at low temperature (10-25 °C) and normal pressure. This technical invention provides a new reference for low-cost degradation of dye wastewater.

Description of drawings:

Figure 1 Effect diagram of the concentration of Fe ³⁺ on the catalyst activity;

Fig. 2 The effect diagram of water bath temperature on catalyst activity;

Fig. 3 The impact diagram of drying time on catalyst activity;

Figure 4 Fe ₂ O ₃ / acrylic chelate fiber degradation effect diagram of reactive red dye;

Figure 5 Fe ₂ O ₃ / the reusability of acrylic fiber chelate fiber catalyst;

The universal applicability of Fig. 6 Fe ₂ O ₃ / acrylic fiber chelate fiber catalyst;

Figure 7 CuO/acrylic chelate fiber degradation effect diagram of reactive red dye;

Figure 8 Electron micrographs of heterogeneous Fenton reagent: (a) Fe ₂ O ₃ /acrylic chelate fiber, (b) CuO/acrylic chelate fiber;

Fig. 9 Schematic diagram of heterogeneous photo-Fenton catalytic degradation of dyes.

specific implementation plan

Embodiment 1: the preparation of heterogeneous Fenton's reagent---Fe ₂ O ₃ / acrylic fiber chelate fiber

Put 0.50 g of carrier fibers in 50 mL of Fe ³⁺ solution, and perform a coordination reaction in a water bath at 70 °C for 3 h to obtain Fe ³⁺ -acrylic fiber chelate fibers; add lye to adjust the pH to alkaline to generate Fe(OH) ₃ /Acrylic chelate fiber; washing, suction filtration, heating and decomposing the filtered solid in an oven, cooling to room temperature to obtain Fe ₂ O ₃ /acrylic chelate fiber catalyst.

The effect of different concentrations of Fe ³⁺ on the catalytic activity of Fenton's reagent was studied. Keeping other preparation conditions unchanged, adjusting the concentration range of Fe ³⁺ from 0.05 mol/L to 0.11 mol/L, the prepared catalyst was subjected to the photo-Fenton catalytic degradation experiment of reactive red dye, and the calculated degradation rate results are shown in Figure 1. It can be seen from the figure that the Fenton reagent prepared from 0.10 mol/L Fe ³⁺ solution has the best photocatalytic effect and the highest activity.

Embodiment 2: the preparation of heterogeneous Fenton's reagent---Fe ₂ O ₃ / acrylic fiber chelate fiber

As in Example 1, the difference is that the temperature of the water bath ranges from 40-90°C. After the photocatalytic reaction, the calculated degradation rate results are shown in Figure 2. It can be seen from the figure that the Fenton reagent prepared at 70 °C has the best photocatalytic effect and the highest activity.

Embodiment 3: _the preparation of heterogeneous Fenton's reagent--- _Fe2O3 /acrylic fiber chelate fiber

As in Example 1, the difference is that the drying time ranges from 2-12 h. After the photocatalytic reaction, the calculated degradation rate results are shown in Figure 3. It can be seen from the figure that the Fenton reagent prepared under 6 h has the best photocatalytic effect and the highest activity.

Embodiment 4: Degradation experiment _{of Fe2O3} /acrylic fiber chelate fiber to reactive red dye

Prepare a reactive red dye solution with a concentration of 50 mg/L. At the maximum absorption wavelength (λ _max =530 nm), the measured absorbance is A ₀ . Take 30 mL of the dye solution and add hydrogen peroxide and 0.03 gFe ₂ O ₃ /acrylic chelate After the fiber catalyst is mixed evenly, it is carried out in a photocatalytic reactor, and the light source is a 300 W Xe lamp. At the same time, a control experiment was carried out. Every 20 minutes, measure the absorbance A _t at the maximum absorption wavelength of the solution, and calculate the degradation rate D, the calculation formula of the degradation rate D=(1-A _t /A ₀ )×100%. The change relationship of the degradation rate with time is listed in Figure 4. It can be seen from the figure that the degradation rate of reactive red dye can be close to 100% in 100 min.

Embodiment 5: the reusability of Fe ₂ O ₃ / acrylic fiber chelate fiber

Prepare a group of mixed solutions with the same dye concentration and hydrogen peroxide content, and add 0.03 g Fe ₂ O ₃ /acrylic chelate fiber catalyst for photocatalytic reaction. After the reaction, the catalyst was separated by filtration and washed with distilled water for the next reaction. The experimental results are shown in Figure 5. It can be seen from the figure that when the catalyst is reused for the 7th time, the degradation rate of the dye is still above 80%, indicating that the heterogeneous Fenton reagent prepared by this method has successfully solved the problem of the loss of catalytically active components. It can be reused many times by simple filtering.

Embodiment 6: _the universal applicability of _Fe2O3 /acrylic chelate fiber

0.03 g Fe ₂ O ₃ /acrylic chelate fiber catalyst was used to degrade reactive yellow, reactive red and methyl orange dye solutions respectively, and the experimental results are shown in Figure 6. As can be seen from the figure, the catalyst prepared by this method can achieve 100% degradation of reactive yellow, reactive red and methyl orange three water-soluble dyes, indicating that the heterogeneous Fenton reagent prepared by this method has high catalytic activity.

the

Embodiment 7: the preparation of heterogeneous Fenton's reagent---CuO/acrylic fiber chelate fiber

Put 0.50 g of carrier fibers in 50 mL of 0.10 mol/L Cu ²⁺ solution, and perform a coordination reaction in a water bath at 50 °C for 2 h to obtain Cu ²⁺ -acrylic fiber chelate fibers; add lye to adjust the pH to alkaline, and generate Cu (OH) ₂ /acrylic chelate fiber; washing, suction filtration, heating the filtered solid in an oven for 4 h, and cooling to room temperature to obtain CuO/acrylic chelate fiber catalyst.

the

Embodiment 8: Degradation experiment of CuO/acrylic fiber chelate fiber to reactive red dye

As in Example 4, the difference is that the catalyst is CuO/acrylic chelate fiber, and the relationship of the degradation rate with time is shown in Figure 7. It can be seen from the figure that the degradation rate of reactive red dye can be close to 100% in 120 min.

Claims (6)

1. a preparation method for heterogeneous Fenton reagent, is characterized in that, the method comprises the following steps:

Step 1, carrier fibre is placed in to metal salt solution 40-90 ℃ water-bath, obtains metal ion carrying fiber;

Step 2, add alkali lye to regulate pH to alkalescence, generate hydroxide, washing, suction filtration, obtains metal hydroxides carrying fiber;

Step 3, the solid leaching is placed in baking oven and heats 2-12 h, be cooled to room temperature, obtain metal oxide supported fiber, i.e. heterogeneous Fenton reagent.

2. the preparation method who states according to step 1 in claim 1, is characterized in that: described carrier fibre is the acrylic fibers chelate fibre with strong coordination ability.

3. according to the preparation method described in step 1 in claim 1, it is characterized in that: described metal salt solution is to contain Fe ³⁺, Cu ²⁺in the concentration of any one metal ion configuration be the aqueous solution of 0.05-0.11 mol/L.

4. according to the preparation method described in step 2 in claim 1, it is characterized in that: described alkali lye can be NaOH, potassium hydroxide, any one in ammoniacal liquor.

5. according to the preparation method described in step 2 in claim 1, it is characterized in that: described metal hydroxides is iron hydroxide, any one of Kocide SD.

6. according to the preparation method described in step 3 in claim 1, it is characterized in that: described metal oxide is iron oxide, any one of cupric oxide.

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