Method for piezocatalytic coupling peracetic acid activation treatment of antibiotic wastewater and elimination of biological toxicity

Abstract

The present application relates to a kind of piezoelectric catalytic coupling peracetic acid activation treatment antibiotic wastewater and eliminate biological toxicity method.The present application uses CoOOH nanosheet as catalyst, and is assisted with piezoelectric technology, synergistic activation peracetic acid treatment antibiotic wastewater, CoOOH nanosheet surface contains rich surface hydroxyl, oxygen vacancy and other high catalytic active sites, can quickly catalyze activation peracetic acid degradation pollutant;The introduction of piezoelectric technology can produce the separation of piezoelectric electron hole on the one hand, and the hydroxyl generated by piezoelectric electron and hole oxidation can further mediate the activation of peracetic acid, on the other hand, the breakage of ultrasonic cavitation bubble can constantly stimulate the surface of CoOOH to produce dynamic defects in the whole reaction process, increase the active site of catalyst, activate oxidant, effectively solve the problem that active site on the surface of catalyst is consumed in catalytic process, can realize efficient and durable pollutant removal.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for treating antibiotic wastewater and eliminating biological toxicity by piezoelectric catalytic coupling peracetic acid activation, and belongs to the field of chemistry and environment. BACKGROUND

[0002] With the improvement of living and economic level, more and more antibiotics are widely used in human production and life. However, the emergence of superbugs means that the abuse of antibiotics will pose a deadly threat to humans and organisms. With the increasing use and discharge of antibiotics, antibiotics have caused serious pollution to the environment. Compared with conventional physical and biological methods, advanced oxidation process has the advantages of high removal rate, low cost, high mineralization rate, good safety, etc., and is an effective method for rapid degradation of antibiotics, elimination of biological toxicity and reduction of resistance gene risk. The advanced oxidation process based on peracetic acid is a new type of water treatment technology, which has attracted the attention of many researchers. Peracetic acid is an organic acid synthesized by acetic acid and H2O2 under the catalysis of sulfuric acid, which has the advantages of no by-product, low biological toxicity, strong oxidation ability, etc. Peracetic acid has an O-O bond similar to hydrogen peroxide and persulfate, but compared with other oxidants, it has a lower O-O bond energy, and is more easily activated to break and produce active substances to degrade pollutants. In addition, the decomposition of peracetic acid can also provide carbon source for subsequent biochemical treatment. Therefore, the advanced oxidation process based on peracetic acid is a pollution removal technology with great development prospect.

[0003] So far, there are mainly three ways to activate peracetic acid: external input energy, homogeneous catalysis and heterogeneous catalysis. Among them, transition metal catalysts are of great concern due to their excellent catalytic performance, excellent stability and economic benefits. However, the intrinsic catalytic activity of non-homogeneous metal catalysts for peracetic acid is low, and the active sites are easily consumed during the reaction process, which seriously hinders the development of peracetic acid-based advanced oxidation processes. At present, piezoelectric catalysis has attracted widespread research interest in wastewater treatment due to its simple operation, cleanliness and high efficiency. Similar to the photocatalytic process, under the action of external mechanical force (commonly used low-frequency ultrasound), piezoelectric materials will deform to produce polarization and built-in electric field, realize continuous separation of electrons and holes, and attract them to the opposite surface to react with water or dissolved oxygen to generate active oxygen species for wastewater treatment, realizing the conversion of mechanical energy to chemical energy. In the ultrasonic process, the high pressure and high temperature energy released under the collapse of cavitation bubbles, the action of microjet and shock wave and the occurrence of cavitation process will cause the change of the microstructure of the metal material surface and the plastic deformation, which will promote the in-situ generation of dynamic defects of the catalyst and enhance the catalytic activity of the catalyst. Therefore, the combination of piezoelectric technology and other advanced oxidation processes will be able to provide a sustainable solution for wastewater purification. Cobalt hydroxyl oxide (CoOOH) as an important intermediate state material in the conversion path of cobalt hydroxide to cobalt oxide, due to its high efficient electron transfer efficiency, high density of surface hydroxyl center and various surface active sites, has great application potential in the field of high-performance heterogeneous catalysis. However, at present, cobalt hydroxyl oxide (CoOOH) is mostly used as an electrode material, and CoOOH nanosheet as a catalyst to activate peracetic acid, and assisted by piezoelectric technology to promote the activation of oxidants to realize the efficient generation of active oxygen species, for promoting antibiotic degradation, no any research report has been reported.

[0004] Therefore, in view of the existing problems of low catalytic activity and few active sites of catalysts, it is urgent to develop a new advanced oxidation technology for activating peracetic acid. SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides a method for piezoelectric catalysis coupled with peracetic acid activation to treat antibiotic wastewater and eliminate biological toxicity. SUMMARY:

[0007] The application uses CoOOH nanosheets synthesized by a green and efficient two-step liquid-phase chemical method as a catalyst, and assists in piezoelectric technology to cooperatively activate peracetic acid to treat antibiotic wastewater. The CoOOH nanosheet surface contains rich surface hydroxyl groups, oxygen vacancies and other high-catalytic-activity sites, which can quickly catalyze and activate peracetic acid to degrade pollutants; the introduction of piezoelectric technology can produce the separation of piezoelectric electrons and holes on one hand, and the hydroxyl groups generated by the oxidation of piezoelectric electrons and holes can further mediate the activation of peracetic acid on the other hand; in addition, the ultrasonic cavitation bubble collapse can continuously excite dynamic defects on the surface of CoOOH in the whole reaction process, increase the catalytic reaction activity sites and activate oxidants, effectively solve the problem of consumption of the surface active sites of the catalyst in the catalytic process, and can realize efficient and persistent pollutant removal; in addition, the introduction of piezoelectric technology also enhances the sterilization and disinfection capacity of the system, effectively reduces the ecological risk of antibiotic pollution, and is more conducive to the practical application and popularization of the advanced oxidation process.

[0008] The technical scheme of the application is as follows:

[0009] A method for treating antibiotic wastewater and eliminating biological toxicity by piezoelectric catalysis coupled with peracetic acid activation, comprising the following steps:

[0010] CoOOH nanosheets are added to the wastewater to be treated, and then peracetic acid is added, and the mixture is placed in a piezoelectric ultrasonic device for ultrasonic treatment in the dark. CoOOH generates dynamic oxygen vacancies under ultrasonic conditions, and the generated piezoelectric electrons and holes oxidize to generate hydroxyl groups, which directly activate peracetic acid together, thereby realizing wastewater treatment.

[0011] According to the application, the wastewater to be treated is antibiotic wastewater.

[0012] According to the application, the antibiotic is a sulfonamide antibiotic.

[0013] According to the application, the sulfonamide antibiotic is sulfamethoxazole, sulfathiazole, sulfadiazine or sulfamethazine.

[0014] According to the application, the concentration of the antibiotic in the antibiotic wastewater is 10-30 μmol / L, the pH of the solution is 5-11, and the temperature is 20℃.

[0015] According to the application, the dosage of CoOOH nanosheets in the wastewater to be treated is 0.05-0.2 g / L.

[0016] According to the application, the concentration of peracetic acid in the wastewater to be treated is 50-400 μmol / L.

[0017] According to the application, the ultrasonic power is 100-120 W, the frequency is 30-50 KHZ, and the whole reaction time is 15-45 min.

[0018] According to the application, the CoOOH nanosheet is prepared by the following method:

[0019] The NaOH solution is added into the Co 2+ After stirring and mixing, the solution is treated by ultrasonic, then the NaClO solution is added, and the ultrasonic treatment is continued to obtain a dark brown sample, which is washed by water, centrifuged, and dried to obtain the CoOOH.

[0020] According to the application, the concentration of the NaOH solution is 0.5-2 mol / L; the Co 2+ The Co 2+ The volume ratio of the Co

[0021] According to the application, the ultrasonic treatment is performed at an ultrasonic power of 100-120 W, a frequency of 30-50 KHZ, and an ultrasonic time of 1 min.

[0022] According to the application, the concentration of the NaClO solution is 0.8-1 mol / L, and the volume ratio of the NaClO solution to the Co 2+ The volume ratio of the Co

[0023] According to the application, the ultrasonic treatment is performed at an ultrasonic power of 100-120 W, a frequency of 30-50 KHZ, and an ultrasonic time of 10 min.

[0024] According to the application, the washing is performed by washing the brown precipitate sample with deionized water, centrifuging the sample several times at 4000 rpm until the eluent is neutral, drying the sample in a 60℃ oven for 12 h, grinding the sample into powder, and passing the powder through a 100-mesh sieve.

[0025] The application has the following beneficial effects:

[0026] 1. The treatment method of the application is a new advanced oxidation process, CoOOH nanosheet is used as a catalyst, and piezoelectric technology is used to activate peracetic acid to treat antibiotic wastewater, the piezoelectric ultrasonic technology with low energy consumption is introduced into the peracetic acid-based advanced oxidation process, on the one hand, piezoelectric electrons are generated under the activation of CoOOH under ultrasonic, which further promotes the activation of peracetic acid, and the recombination rate of piezoelectric electrons and holes is greatly reduced after the piezoelectric electrons are captured by peracetic acid, thereby accelerating the removal of pollutants, on the other hand, the ultrasonic cavitation bubble collapse can promote the rapid generation of dynamic defects and active sites on the surface of CoOOH nanosheet, solving the problems of difficult regeneration of active sites of existing catalysts and low recycling rate of catalysts, and realizing efficient and persistent removal of pollutants, and promoting the practical application of the advanced oxidation process.

[0027] 2、The active substances generated by the new advanced oxidation process developed in the application include R-O·, 1 O2 and Co(IV)=O, which have strong ability to resist environmental background influence and show potential in treating actual wastewater; in addition, the process can also kill bacteria, disinfect and eliminate resistance genes, so as to effectively treat antibiotic wastewater and reduce environmental risk.

[0028] 3、The synthesis method of the CoOOH nanosheet in the application is green, simple, high-yield, pollution-free and low-energy-consumption, and is suitable for industrial production. The synthesized CoOOH can effectively activate peroxiacetic acid to generate various active substances to degrade pollutants. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The XRD spectrum of the CoOOH nanosheet prepared in Example 1 of the application.

[0030] Figure 2 The TEM diagram of the CoOOH nanosheet prepared in Example 1 of the application.

[0031] Figure 3 The electron paramagnetic resonance (EPR) spectrum diagram of the CoOOH nanosheet in Example 1 before and after ultrasonic treatment.

[0032] Figure 4 The activation efficiency comparison diagram of peroxiacetic acid in different systems of Example 1 and Comparative Example 1 of the application.

[0033] Figure 5 The performance comparison diagram of different systems of Example 1 and Comparative Example 1 of the application on degrading sulfathiazole.

[0034] Figure 6 The EPR spectrum of different systems of Example 1 and Comparative Example 1 of the application.

[0035] Figure 7 The transient piezoelectric current spectrum of Example 1 of the application.

[0036] Figure 8 The recycling performance diagram of Example 1 of the application.

[0037] Figure 9 The influence of different coexisting anions in Experimental Example 3 on the degradation performance of sulfathiazole.

[0038] Figure 10 The inactivation comparison diagram of resistant Escherichia coli in Experimental Example 4. DETAILED DESCRIPTION

[0039] The application will be further described below by means of specific embodiments and in conjunction with the drawings, but is not limited thereto.

[0040] The raw materials used in the examples are all commercially available products.

[0041] Example 1

[0042] Preparation of CoOOH nanosheets:

[0043] Take 25 mL of 1 mol / L NaOH solution and 10 mmol / L Co solution. 2+ 100 mL of the solution was mixed and stirred, then sonicated for 1 min in an ultrasonic instrument. 0.9 mol / L NaClO solution was then added, and sonication continued for another 10 min. The resulting product was washed with water and centrifuged several times to obtain a dark brown solid material. This material was dried in a 60℃ oven for 12 h, then ground and sieved to obtain CoOOH nanosheet powder.

[0044] The XRD pattern of the synthesized CoOOH nanosheets is as follows: Figure 1 As shown.

[0045] TEM image of the synthesized CoOOH nanosheets is shown below. Figure 2 As shown, the CoOOH catalyst exhibits a hexagonal sheet-like structure with a side length of approximately 50 nm.

[0046] The method for treating antibiotic wastewater based on CoOOH nanosheet piezoelectric catalysis coupled with peracetic acid activation includes the following steps:

[0047] At room temperature, 100 mL of a 20 μmol / L sulfathiazole simulated solution was added to a beaker, along with 10 mg of the CoOOH nanosheets prepared above and 200 μL of 0.1 mol / L peracetic acid. The beaker was then placed in an ultrasonic instrument with an ultrasonic power of 110 W and a frequency of 40 kHz for 30 min. During the reaction, 1 mL of the sample was taken at regular intervals (0, 1, 2, 5, 10, 20, 30 min) and filtered through a 0.22 μm filter membrane. The concentration of sulfathiazole was determined by high performance liquid chromatography to verify its degradation effect.

[0048] Experimental Example 1

[0049] The CoOOH nanosheet powder obtained in Example 1 was dispersed in 100 mL of water, and after being ultrasonically treated for 30 min, it was dried, ground, and sieved.

[0050] The electron paramagnetic resonance spectra of CoOOH nanosheets before and after ultrasonic treatment are as follows: Figure 3 As shown. (Through) Figure 3 It can be seen that after ultrasonic treatment, the EPR of CoOOH nanosheets captured more unpaired electron signals at g=2.00, indicating that more oxygen vacancies were generated.

[0051] Comparative Example 1

[0052] The method for treating antibiotic wastewater based on CoOOH nanosheet piezoelectric catalysis coupled with peracetic acid activation as described in Example 1 differs in that:

[0053] The beaker was placed on a magnetic stirrer and stirred at 750 rpm to replace ultrasonic treatment. The rest of the operation and dosage were exactly the same as in Example 1.

[0054] Experimental Example 2

[0055] The activation efficiency of the CoOOH / peracetic acid system on peracetic acid under different effects of stirring and piezoelectric ultrasound in Example 1 and Comparative Example 1 is compared. Figure 4 As shown. (Through) Figure 4 It can be seen that the introduction of piezoelectric ultrasonic technology significantly improved the activation efficiency of peracetic acid, indicating that the piezoelectric technology promoted the generation of more active sites for activating peracetic acid on the catalyst surface.

[0056] Comparison of the pollutant degradation performance of the CoOOH / peracetic acid system under different effects of stirring and piezoelectric ultrasound. Figure 5 As shown. (Through) Figure 5 It can be seen that the introduction of piezoelectric ultrasonic technology has significantly improved the system's performance in removing pollutants.

[0057] EPR spectra of the CoOOH / peracetic acid system under different conditions of stirring and piezoelectric sonication are as follows: Figure 6 As shown. (Through) Figure 6 It can be seen that piezoelectric ultrasound promotes the generation of more RO·, ·OH, and other compounds in the system. 1 Active substances such as O2 can attack sulfathiazole.

[0058] Example 1: The instantaneous piezoelectric current spectrum of the CoOOH / peracetic acid system is shown below. Figure 7 As shown. From Figure 7 During the ultrasonic switching process, CoOOH exhibited regular electron-hole separation, further confirming its stable piezoelectric properties. In the presence of peracetic acid, the generated piezoelectric current increased by 3.5 times, indicating that peracetic acid can act as an electron acceptor, reducing the electron-hole recombination rate.

[0059] Example 1: Experimental results of the cyclic degradation of pollutants using the CoOOH / peracetic acid / piezoelectric system are as follows. Figure 8 As shown, the system still achieved 100% degradation efficiency for pollutants after eight cycles, exhibiting extremely stable catalytic activity. This indicates that the introduction of piezoelectric technology continuously promotes the generation of dynamic defects, maintaining the catalytic activity of the system.

[0060] Experiment Example 3

[0061] The method for treating antibiotic wastewater based on CoOOH nanosheet piezoelectric catalysis coupled with peracetic acid activation as described in Example 1 differs in that:

[0062] Different types of common anions (Cl) were added to sulfathiazole simulated wastewater. - SO2 - NO3 - To explore the application potential of this method in real-world environments.

[0063] Figure 9 This is a comparison of the degradation performance of sulfathiazole by the CoOOH / peracetic acid / piezoelectric system in Experiment 3 under the presence of different anions. Figure 9 It can be seen that the system can still efficiently remove pollutants in the presence of anions, demonstrating excellent resistance to environmental background.

[0064] Experiment Example 4

[0065] The concentration of resistant E. coli was 1×10 6 10 mg of CoOOH catalyst and 200 μL of 0.1 mol / L peracetic acid were added to wastewater with a concentration of CFU / mL, and the mixture was sonicated for 30 min (CoOOH / PAA / US). A control group (CoOOH / PAA) was used without sonication. During the reaction, 1 mL samples were taken at regular intervals (0, 1, 2, 5, 10, 20, 30 min). 200 μL of each sample was then plated on a solid culture medium.

[0066] Figure 10 This study compares the inactivation performance of the CoOOH / peracetic acid / piezoelectric system and the CoOOH / peracetic acid system against resistant Escherichia coli. The CoOOH / peracetic acid piezoelectric system achieved 100% inactivation efficiency against bacteria within 30 minutes. This is mainly due to the introduction of piezoelectric technology, which promotes the decomposition of peracetic acid and generates a large amount of RO· with bactericidal properties.

Claims

1. A method for treating antibiotic wastewater and eliminating biotoxicity by piezoelectric catalysis coupled with peracetic acid activation, comprising the following steps: CoOOH nanosheets were added to the wastewater to be treated, followed by peracetic acid. The wastewater was then subjected to ultrasonic treatment in a piezoelectric ultrasonic device under light-protected conditions. Under ultrasonic conditions, CoOOH generated dynamic oxygen vacancies. The piezoelectric electrons generated by the excitation and the hydroxyl groups generated by the oxidation of holes directly activated the peracetic acid, thereby achieving wastewater treatment. CoOOH nanosheets were prepared by the following method: Add NaOH solution to Co 2+ After stirring and mixing in the solution, the sample was ultrasonically treated, then NaClO solution was added, and ultrasonic treatment was continued to obtain a dark brown sample. After washing with water, centrifuging, and drying, CoOOH was obtained. The concentration of the NaOH solution is 0.5-2 mol / L; Co 2+ The solution is a CoCl2 solution with a concentration of 8-12 mmol / L. 2+ The volume ratio of the solution to the NaOH solution was 1:(2-6). During the preparation of CoOOH nanosheets, the ultrasonic treatment was performed with an ultrasonic power of 100-120W, a frequency of 30-50KHZ, and an ultrasonic time of 1min.

2. The method according to claim 1, characterized in that, The wastewater to be treated is antibiotic wastewater, and the antibiotics are sulfonamide antibiotics, specifically sulfamethoxazole, sulfathiazole, sulfadiazine, or sulfadiazine. The concentration of the antibiotics in the wastewater is 10-30 μmol / L, the pH of the solution is 5-11, and the temperature is 20℃.

3. The method according to claim 1, characterized in that, The dosage of CoOOH nanosheets in the wastewater to be treated is 0.05-0.2 g / L.

4. The method according to claim 1, characterized in that, The concentration of peracetic acid in the wastewater to be treated is 50-400 μmol / L.

5. The method according to claim 1, characterized in that, The ultrasonic power of the wastewater to be treated is 100-120W, the frequency is 30-50KHZ, and the entire reaction time is 15-45min.

6. The method according to claim 1, characterized in that, During the preparation of CoOOH nanosheets, the concentration of NaClO solution is 0.8-1 mol / L. The NaClO solution reacts with Co... 2+ The solution volume ratio is 1:(15-25).

7. The method according to claim 1, characterized in that, The ultrasonic power for ultrasonic treatment of the wastewater is 100-120W, the frequency is 30-50KHZ, and the ultrasonic time is 10min.

8. The method according to claim 1, characterized in that, The washing process in the preparation of CoOOH nanosheets involves washing the brown precipitate sample with deionized water, centrifuging at 4000 rpm several times until the eluent is neutral, drying in a 60℃ oven for 12 hours, grinding into powder, and passing through a 100-mesh sieve.

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