Method for synchronously activating persulfate using "light-heat-fes 2 / dust-free cloth" and use

Abstract

A method for synchronously activating persulfate using "light-heat-FeS2 / dust-free cloth" and a use. Metal iron sulfide FeS2 is loaded to the surface of black dust-free cloth ALC in an ultrasonic dispersion manner to form a FeS2 / ALC integrated photo-thermal catalyst. Persulfate is activated by using Fe2+, FeS2 / ALC absorbs solar energy to heat and activate the persulfate, and sunlight directly activates the persulfate, so that the "light-heat-FeS2 / dust-free cloth integrates three activation effects for synchronously activating the persulfate, achieving efficient degradation of organic pollutants in water.

Description

A method for simultaneous activation of persulfate by "light-heat-FeS2 / dust-free cloth" and its application Technical Field

[0001] The present invention belongs to the field of sewage treatment and relates to a combination of metal sulfide as a catalyst and a black dust-free cloth to achieve efficient degradation of organic pollutants in sewage. Specifically, it is a method for synchronously activating persulfate by "light-heat-FeS2 / dust-free cloth". Background Art

[0002] Compared to other advanced oxidation technologies, activated persulfate advanced oxidation technology based on sulfate radicals has garnered widespread attention in recent years due to its advantages, including high redox potential, wide pH range, easier transport than H₂O₂, and ability to oxidize pollutants that OH cannot. Currently, reported activated persulfate methods include energy activation (such as thermal activation, photoactivation, ultrasonic activation, and microwave activation); electron transfer activation (including electrochemical activation, transition metal / transition metal ion activation, and photogenerated electron activation); and other methods (such as alkaline activation and benzoquinone activation). However, these single activation methods either have high energy consumption or low activation efficiency, making them unsuitable for large-scale application in practical production.

[0003] Solar energy is the cleanest and most abundant resource. Using solar energy to activate persulfate is considered to be a solution to the SO4 generation under the energy and environmental crisis. – However, since only about 5% of the ultraviolet light in sunlight can activate persulfate, direct sunlight is inefficient. Therefore, a combination of multiple activation methods is necessary to improve activation efficiency.

[0004] Transition metal sulfides, such as cobalt disulfide, iron disulfide, and tungsten disulfide, are semiconductor materials with high photoelectric sensitivity, electrical switching ratio, and electron mobility. Theoretically, the combination of transition metal sulfides and sunlight to activate persulfate can efficiently degrade organic pollutants. Currently, there are no reports on the use of transition metal sulfides in conjunction with solar energy to degrade organic pollutants. Therefore, the present invention uses transition metal sulfides in combination with solar energy to degrade organic pollutants in water, thereby improving water quality.

[0005] Summary of the Invention

[0006] The present invention uses ultrasonic dispersion to load metallic iron sulfide (FeS2) onto the surface of black dust-free cloth (ALC) to form FeS2 / ALC integrated photothermal catalyst. 2+ Activate persulfate, FeS2 / ALC absorbs solar energy to heat and activate persulfate, and sunlight directly activates persulfate, thereby achieving the simultaneous activation of persulfate by "light-heat-FeS2 / dust-free cloth", realizing the efficient degradation of organic pollutants in water.

[0007] The detailed steps are as follows:

[0008] (1) Cut the black dust-free cloth into a rectangle of 2 cm × 4 cm.

[0009] (2) Add 80 mg of FeS2 powder to a beaker containing 20 mL of ultrapure water. Use tweezers to add two pieces of black dust-free cloth cut in (1) to the beaker and ultrasonically disperse for 30 minutes to evenly disperse the FeS2 powder on the surface of the black dust-free cloth.

[0010] (3) After the ultrasonic treatment, two pieces of black dust-free cloth loaded with FeS2 powder (FeS2 / ALC) were taken out with tweezers and placed at room temperature to dry naturally for 24 h.

[0011] (4) Use tweezers to pick up two dried FeS2 / ALC sheets and lay them flat on the bottom of a custom-made glass interfacial reactor. Connect the glass interfacial reactor, glass doser, and peristaltic pump with silicone tubing. Add 100 mL of artificial wastewater containing a certain concentration of model pollutants and a certain concentration of PMS solution to the glass doser in sequence to achieve a final PDS content of 8.0 mmol / L. The ambient temperature was 20 ± 2°C and the humidity was 60 ± 10%.

[0012] The above ultrasonic method uses ultrasound to attach FeS2 powder to the ALC surface. The sewage flows continuously through the glass interface reactor under the pressure of a peristaltic pump. PDS is activated by the FeS2-ALC at the bottom of the reactor to degrade the model pollutants.

[0013] Preferably, in step (1), a black dust-free cloth is used as the loading carrier of FeS2 powder, which has a good loading effect, can be reused many times, and is inexpensive.

[0014] Preferably, the amount of FeS2 powder added in step (2) is 80 mg, which can effectively ensure that the model pollutants can be completely degraded, prevent a large amount of Fe ions from being dissolved in the wastewater, and is in line with economic concepts.

[0015] Preferably, the flow rate of the peristaltic pump in step (4) is 10 mL / min. If the speed is too fast, the hydraulic retention time is short, resulting in low PMS activation efficiency; if the speed is too slow, the sewage treatment efficiency is greatly reduced.

[0016] In addition, the present invention provides an activated persulfate catalyst and application thereof.

[0017] An activated persulfate catalyst is used to load metallic iron sulfide FeS2 onto the surface of black dust-free cloth ALC by ultrasonic dispersion to form an integrated FeS2 / ALC photothermal catalyst.

[0018] Application of FeS2 / ALC integrated photothermal catalyst for efficient degradation of organic pollutants in water.

[0019] Compared with the prior art, the beneficial effects of this method are embodied in:

[0020] (1) Low energy and high efficiency. By utilizing clean energy such as solar energy and synergistically activating PDS through photothermal / metal sulfide, the operating energy consumption is reduced and the activation efficiency and degradation efficiency of organic matter are increased.

[0021] (2) No need for solid-liquid separation. FeS2 is attached to a dust-free cloth to solve the problem of difficult solid-liquid separation between the catalyst and the treated water in traditional activation methods.

[0022] (3) Large water volume. The continuous flow method is used to treat sewage, which is more suitable for actual engineering applications and increases the single sewage treatment volume.

[0023] (4) Low cost. The production method is simple, uses less materials, and is inexpensive. At the same time, FeS2 / dust-free cloth can be recycled many times.

[0024] (5) Wide range of applications. This method can degrade a wide variety of organic matter and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 examines the catalytic effect of FeS2 / ALC in different systems. Considering that FeS2 is also an excellent photocatalyst, two conditions of light and dark were set respectively.

[0026] Figure 2, investigates the removal effect of FeS2 / ALC on different model pollutants.

[0027] Figure 3, investigates the recycling effect of FeS2 / ALC. DETAILED DESCRIPTION

[0028] Implementation Example 1

[0029] Six parallel experiments were conducted using a 20 μmol / L carbamazepine solution: dark / FeS2 / ALC, photothermal / FeS2 / ALC, dark / PDS, photothermal / PDS, dark / FeS2 / ALC / PDS, and photothermal / FeS2 / ALC / PDS. The reaction time was 60 minutes. Figure 1 shows that, under the same conditions, only the photothermal / FeS2 / ALC / PDS system completely degraded carbamazepine within 60 minutes, demonstrating that FeS2-ALC can efficiently activate PMS under photothermal conditions.

[0030] Implementation Example 2

[0031] Prepare 20 μmol / L carbamazepine, diclofenac sodium, and sulfadiazine, then add 20 μmol / L carbamazepine solution and 8.0 mmol / L PDS solution in sequence, 1 kW / m 2 Figure 2 shows that, under the same conditions, different organic compounds can be efficiently degraded by the system, with a degradation rate of over 90%.

[0032] Implementation Example 3

[0033] In order to explore the stability and durability of FeS2-ALC, a cycle experiment of FeS2-ALC membrane was carried out. The dosage of carbamazepine and PMS was 20 μmol / L and 8.0 mmol / L, respectively, and the flow rate was 1 kW / m 2 Figure 3 shows that the FeS2-ALC membrane can completely degrade carbamazepine after 15 cycles of irradiation under high light intensity and a reaction time of 60 minutes. This indicates that the FeS2-ALC membrane can be reused and has good stability and durability.

Claims

1. A method for simultaneous activation of persulfate by "light-heat-FeS2 / dust-free cloth", in which metal iron sulfide FeS2 is loaded onto the surface of black dust-free cloth ALC by ultrasonic dispersion to form an integrated FeS2 / ALC photothermal catalyst. 2+ Activate persulfate, FeS2 / ALC absorbs solar energy to heat and activate persulfate, and sunlight directly activates persulfate, thereby achieving the simultaneous activation of persulfate by "light-heat-FeS2 / dust-free cloth".

2. A method for achieving efficient degradation of organic pollutants in water, characterized in that: The method described in claim 1 is used to activate persulfate in sewage; specifically, the sewage continuously flows through the glass interface reactor under the pressure of a peristaltic pump, and PDS is activated by the FeS2 / ALC integrated photothermal catalyst at the bottom of the reactor to degrade the model pollutants.

3. The method according to claim 1 or 2, characterized in that: The metallic iron sulfide is FeS2 powder.

4. The method according to claim 1 or 2, characterized in that: Two pieces of 2cm×4cm rectangular black dust-free cloth ALC added 80mg of FeS2 powder.

5. The method according to claim 2, characterized in that: Ambient temperature 20±2℃, humidity 60±10%.

6. The method according to claim 2, characterized in that: The flow rate of the peristaltic pump was 10 mL / min.

7. The method according to claim 2, characterized in that: The specific steps are as follows: (1) Cut the black dust-free cloth into a rectangle of 2 cm × 4 cm; (2) Add 80 mg of FeS2 powder to a beaker containing 20 mL of ultrapure water, add two pieces of black dust-free cloth cut in (1) to the beaker with tweezers, and perform ultrasonic dispersion for 30 min to evenly disperse the FeS2 powder on the surface of the black dust-free cloth; (3) After the ultrasound was completed, two pieces of black dust-free cloth FeS2 / ALC loaded with FeS2 powder were taken out with tweezers and placed at room temperature to dry naturally for 24 h; (4) Use tweezers to pick up two pieces of dried FeS2 / ALC and spread them flat on the bottom of the glass interfacial reactor; connect the glass interfacial reactor, glass doser, and peristaltic pump with silicone tubes; add 100 mL of artificial wastewater containing a certain concentration of model pollutants and a certain concentration of PMS solution to the glass doser in sequence so that the PDS in the final wastewater is 8.0 mmol / L.

8. An activated persulfate catalyst, characterized in that: Metallic iron sulfide FeS2 was loaded onto the surface of black dust-free cloth ALC by ultrasonic dispersion to form an integrated FeS2 / ALC photothermal catalyst.

9. Use of the activated persulfate catalyst according to claim 8 for efficient degradation of organic pollutants in water.

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