CN115040822B

CN115040822B - Degradation of fluoroquinolones by manganese oxide and persulfate mechanochemical method

Info

Publication number: CN115040822B
Application number: CN202210681856.4A
Authority: CN
Inventors: 王楠; 汪泽群; 吕田钰; 朱丽华
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2022-06-15
Filing date: 2022-06-15
Publication date: 2023-07-04
Anticipated expiration: 2042-06-15
Also published as: CN115040822A

Abstract

The invention relates to a method for degrading fluoroquinolone by utilizing manganese oxide and persulfate mechanochemical method, belonging to the field of treatment of dangerous solid waste of organic pollutants. Synchronously or stepwise adding manganese oxide and persulfate into a ball-milling reaction tank containing fluoroquinolone and grinding balls, starting a ball-milling instrument, and inducing MnO on one hand by utilizing mechanical force effect generated by ball-milling collision ₂ And on the other hand, activating PMS to generate various active oxygen species, and the active oxygen species and the PMS synergistically attack fluoroquinolone-oxide antibiotics to realize harmless degradation. The invention has the following characteristics: simple operation, mild reaction condition and good treatment effect, and can completely eliminate the antibacterial toxicity of antibiotics.

Description

Degradation of fluoroquinolones by manganese oxide and persulfate mechanochemical method

Technical Field

The invention belongs to the field of treatment of dangerous solid wastes of organic pollutants, and particularly relates to degradation of fluoroquinolone by using a manganese oxide and persulfate mechanochemical method, in particular to harmless treatment of antibiotic solid wastes.

Background

In 2013, the total usage amount of antibiotics is 16.2 ten thousand tons, wherein Fluoroquinolones (FQs) are 2.73 ten thousand tons and account for 17 percent. The large amount of antibiotics is used and continuously discharged, so that the antibiotics become a type of 'pseudo-persistent pollutant', and the antibiotics not only harm ecological environment, but also induce drug-resistant strains to generate. FQs are third generation quinolone antibacterial agents, commonly known as norfloxacin, ofloxacin, ciprofloxacin, and the like. FQs has three main structural units on its molecule: pyridonic acid (pharmacophore), benzene ring, piperazine ring (synergist); because of stable chemical structure, the drug resistance problem is particularly prominent, and the drug resistance rate in China is up to more than 60%. Overdose is one of the main sources of antibiotic contamination; as early as 2008, waste medicines are listed as hazardous wastes in China, but an effective treatment method for the antibiotic overdue medicines is not yet available.

Aiming at the treatment of antibiotic pollution, a plurality of water treatment technologies are researched at home and abroad. Related studies indicate that: the electron cloud density on the FQs piperazine ring is higher, and the active species (OH, SO) which are easy to be enriched with electrons ₄ ^·- 、O ₂ ¹ ) Attack and cleavage occur, so advanced oxidation processes often oxidize and degrade FQs in water by activating peroxymonosulfate to produce an active species; however, the electron cloud density on the pyridone ring of the pharmacodynamic parent nucleus is low, and the pyridone ring is difficult to be subjected to hydroxyl radical (OH) and sulfate radical (SO) ₄ ^·- ) And the like, resulting in FQs degradation products that remain residual antimicrobial activity and mutagenic, may induce the generation and transmission of resistance genes.

For the solid overdue drugs, the solid overdue drugs are generally recycled and then are burned and destroyed in a concentrated way in developed countries, but organic drugs contain heteroatoms such as N, S, halogen and the like, and toxic gas is easy to generate during burning; the expired solid waste is buried, but FQs medicines have certain water solubility, so that the problem of secondary pollution of percolate is solved. The mechanochemical method is a solid-phase treatment technology which has the highest potential to replace incineration treatment of persistent organic pollutants, and has the characteristics of mild reaction conditions, simple and convenient operation and high treatment efficiency. Italian students have used mechanochemical treatment of expired ibuprofen in 2012 to decarboxylate its pharmacophore phenylacetic acid, reducing the pharmacological activity. However, no mechanochemical degradation FQs has been reported. In publication No. CN106000554B, chai Huijuan et al use MnO ₂ Ball milling, oxidizing and degrading organic solid waste (including halogenated organic pollutants, phenols and organic dyes) for grinding agent, mnO ₂ Itself is reduced to Mn ₂ O ₃ Description of MnO ₂ Is an oxidation type grinding agent with potential. Based on the patent, aiming at the structural characteristics of FQs molecular groups, manganese oxide and persulfate are creatively selected as co-grinding agents, on one hand, active lattice oxygen released by the manganese oxide is induced by mechanical force to oxidize a pharmacodynamic mother nucleus, and on the other hand, the mechanical force and the manganese oxide are used for activating the persulfate to generate a plurality of active species to oxidize electron-rich parts in FQs molecules. The coupling effect of catalytic oxidative decarboxylation and active oxygen nucleophilic addition is utilized to promote the decarboxylation and ring opening of the pyridone acid to realize the complete mineralization of the pyridone acid, and a method for harmlessly disposing FQs overdue medicines is established.

Disclosure of Invention

The invention provides a novel method for degrading fluoroquinolone antibiotics by using persulfate and manganese oxide as grinding agents and mechanochemical, wherein lattice oxygen and active species generated by the grinding agents in the ball milling process oxidize and degrade the fluoroquinolone, and the technical problems that degradation products of the fluoroquinolone antibiotics have residual antibacterial activity and mutagenicity and induce generation and propagation of resistance genes in the prior art are solved.

According to the purpose of the invention, a method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical method is provided, which is characterized in that manganese oxide and persulfate are adopted as grinding agents, and are synchronously added or are added into a ball-milling tank containing fluoroquinolone to be treated step by step for ball milling, wherein the step by step addition is to add manganese oxide firstly and then persulfate; lattice oxygen and active species generated by the grinding agent during ball milling oxidize and degrade fluoroquinolones.

Preferably, the mechanical forces generated during ball milling activate the oxides of manganese and persulfate; the manganese oxide is activated by mechanical force effect to release active lattice oxygen; persulfate is catalytically activated by mechanical force effects and manganese oxides to produce reactive oxygen species.

Preferably, the reactive oxygen species are sulfate radicals, hydroxyl radicals, and singlet oxygen.

Preferably, the manganese oxide is added in portions.

Preferably, the manganese oxide is MnO ₂ 、Mn ₂ O ₃ 、Mn ₃ O ₄ And at least one of MnO.

Preferably, the MnO ₂ Is alpha-MnO ₂ 、β-MnO ₂ 、γ-MnO ₂ 、ε-MnO ₂ And delta-MnO ₂ At least one of them.

Preferably, the persulfate is potassium persulfate, sodium persulfate, potassium persulfate, or sodium persulfate.

Preferably, the fluoroquinolone is at least one of ofloxacin, norfloxacin, ciprofloxacin, pefloxacin, and enoxacin.

Preferably, the mass ratio of the grinding agent to the fluoroquinolone is 20:1-5:1.

Preferably, the mass ratio of manganese oxide to persulfate in the grinding agent is 5:1-1:5.

In general, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

(1) The mechanochemical method can rapidly degrade fluoroquinolone antibiotic parent pollutants, can deeply destroy pharmacodynamic parent nuclei, generates small amount of final degradation products without antibacterial activity, and blocks the generation and propagation of resistance genes.

(2) The selected grinding agents are cheap and easily available manganese oxide and persulfate, and the conversion products are nontoxic inorganic metal oxide and sulfate; the degradation process does not need to use an organic solvent for pretreatment, and the reaction condition is mild, the time consumption is short, and the method is rapid and efficient.

Drawings

FIG. 1 shows MnO in example 1 ₂ And PMS mass ratio to synchronous mechanochemical degradation of ofloxacin.

FIG. 2 shows the simultaneous mechanochemical degradation of ofloxacin by mixing different oxides of manganese and PMS in a fixed ratio in example 2.

FIG. 3 shows MnO in example 3 ₂ And PMS mass ratio 1:1, degradation curve of synchronously degrading norfloxacin and accumulation condition of 4 main byproducts.

FIG. 4 is a plot of norfloxacin in the step mechanochemical degradation system of example 4.

FIG. 5 shows the change in bacteriostatic toxicity of ofloxacin before and after mechanochemical treatment in example 5.

FIG. 6 shows the change in bacteriostatic toxicity of norfloxacin before and after mechanochemical treatment in example 5.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

The invention relates to a method for innocent treatment of fluoroquinolone by using manganese oxide and persulfate mechanochemical method, which adopts manganese oxide and persulfate as grinding agents, synchronously or stepwise adds the grinding agents into a ball milling tank containing fluoroquinolone to be treated for ball milling, and utilizes high-energy collision between a grinding ball and reactants to activate the manganese oxide to release active lattice oxygen in situ on one hand and activate persulfate to decompose to generate various active oxygen species (such as sulfate radical, hydroxyl radical, singlet oxygen and the like) on the other hand.

During ball milling, high energy collisions between the balls and the reactants induce the following reactions: (1) M-OH on the surface of manganese oxide as Bronsted alkali to promote dissociation of FQs carboxyl to form coordination unsaturated metal center Mn ^x+ And COO ^- The coordination anchors FQs on the surface of the manganese oxide, and under the effect of mechanical force, the manganese oxide and FQs are further promoted to undergo interfacial electron transfer to initiate the decarboxylation of the pyridonic acid; (2) The mechanical force promotes the M-O-M bond on the surface of the manganese oxide to be broken, and active lattice oxygen is released in situ, so that pyridone is attacked to open the ring and decompose; (3) Mechanical force-activated persulfate decomposition into various active species, e.g., OH, SO ₄ ^·- And/or singlet oxygen ¹ O ₂ ) Attack piperazine ring with higher electron cloud density to degrade completely; (4) Manganese oxide can also act as a catalyst to activate persulfate decomposition to produce active species and is further accelerated by mechanical forces. Under the synergistic effect of the multiple effects, FQs is efficiently degraded and deeply mineralized, so that the antibacterial toxicity of parent pollutants and degradation products is thoroughly eliminated. Compared with the prior advanced oxidation technology, the method solves the problem of secondary pollution of fluoroquinolone antibiotic degradation products, and has mild reaction conditions, high treatment efficiency and practical application potential.

The persulfate and manganese oxide mechanochemical degradation FQs provided by the invention is divided into two types, namely synchronous type and distributed type. In a synchronous degradation system, persulfate and manganese oxide are simultaneously added as grinding agents at the beginning of the ball milling reaction; in the step-by-step degradation system, firstly, manganese oxide is used as a grinding agent to degrade for a certain time, then, whether the manganese oxide needs to be added is determined according to degradation conditions, and after fluoroquinolone is almost completely degraded, persulfate is added to carry out subsequent degradation, so that degradation intermediate products are further eliminated.

In some embodiments, the manganese oxide is MnO ₂ 、Mn ₂ O ₃ 、Mn ₃ O ₄ And MnO; preferably, the manganese oxide is MnO ₂ Characterized by alpha-MnO ₂ 、β-MnO ₂ 、γ-MnO ₂ 、ε-MnO ₂ And delta-MnO ₂ At least one of them.

In some embodiments, the persulfate is potassium monopersulfate, sodium monopersulfate, potassium peroxodisulfate, and sodium peroxodisulfate; preferably, the persulfate is potassium monopersulfate.

In some embodiments, the fluoroquinolone is ofloxacin, norfloxacin, ciprofloxacin, pefloxacin, enoxacin.

In some embodiments, the mass ratio of the grinding agent to the fluoroquinolone is 20:1-5:1, the mass ratio of the manganese oxide to the persulfate in the grinding agent is 5:1-1:5, and the mass ratio of the grinding ball to the reactant is further set to 25:1-75:1.

In some embodiments, the step-wise addition of the grinding agent is divided into at least 3 steps, with each step using manganese oxide as the grinding agent except for the last step of persulfate addition. Preferably, the step-by-step system is a three-step system in which manganese oxide, manganese oxide and persulfate are added respectively, and the mass ratio of the manganese oxide to fluoroquinolone added initially is 1.5:1-6:1, 1.5:1-7.5:1 and 1.5:1-5:1 respectively.

In some embodiments, the grinding balls have two different diameters, namely 8mm and 3mm, in a mass ratio of 2:5 to 5:2.

The invention discloses a method for degrading fluoroquinolone by mechanochemical method, which comprises the following steps:

step 1: firstly, mixing a grinding agent and fluoroquinolone according to the mass ratio of 9:1-3:1, and adding the mixture into a stainless steel ball milling tank as a reaction material; then, stainless steel grinding balls with the diameters of 8mm and 3mm are added, the mass ratio of the stainless steel grinding balls to the stainless steel grinding balls is 2:5-5:2, and the mass ratio of the total mass of the grinding balls to the mass ratio of reactants is 20:1-75:1. And (3) covering the cover, and sealing the tank body and the cover by using a sealing ring.

Step 2: and placing the ball milling tank with the finished material charge on a planetary ball milling instrument at normal temperature and normal pressure, setting the rotating speed to be 100-450 r/min and the total ball milling time to be 5-60 min, and starting the ball milling instrument to perform a mechanochemical degradation experiment. And (3) reacting for a certain time, suspending the ball mill, taking out the ball mill tank, and taking out part of solid powder.

Step 3: accurately weighing 0.02g of the solid powder collected in the step 2, placing the solid powder into a 15mL glass centrifuge tube, and extracting the solid powder for 15min with the aid of ultrasound by adopting 10mL of methanol-water mixed solution (30% -70%); and centrifuging at 14000rpm for 5min, filtering the supernatant with a 0.22 μm filter membrane, diluting with solvent for 10 times, performing High Performance Liquid Chromatography (HPLC) -ultraviolet detector to determine the residual amount of fluoroquinolone, and stopping degradation reaction when the residual antibiotic content is stable.

In some embodiments, the manganese oxide and persulfate are added simultaneously.

In some embodiments, the manganese oxide and persulfate are added in steps.

Example 1

0.20g ofloxacin is taken as degradation object, mnO with the total mass of 1.80g is added ₂ And PMS, wherein MnO ₂ And (3) carrying out synchronous mechanochemical degradation experiments according to the steps 1-3, wherein the mass ratio of the PMS to the ofloxacin is 1:0-0:1, and monitoring the residual quantity of ofloxacin and the accumulation condition of degradation products by adopting HPLC. As shown in a in fig. 1, the degradation rate of the OFX is related to the PMS content in the grinding agent, and when PMS is not added, the degradation rate of the OFX is only 60% after ball milling reaction for 60 min; when the PMS dosage is increased to 33%, the degradation rate of the OFX is gradually increased to 90%; and the PMS dosage is continuously increased to 50%, and the OFX degradation rate exceeds 98%. From the liquid chromatogram of the extract, some degradation products appear at retention times of 1.9, 2.2, 3.5 and 4.2min, etc.,they are respectively abbreviated as t with retention time x (min) _r (x) A. The invention relates to a method for producing a fibre-reinforced plastic composite As shown in b of fig. 1, when PMS is used alone, at t _r (1.9)、t _r (2.2) and t _r Three degradation products occur at (7.6) with peak areas as high as 189, 538 and 173, respectively. As the PMS dosage gradually decreases from 100% to 67%, t _r The peak area of the degradation product at (2.2) gradually decreases to 100 or less; t is t _r The accumulation of degradation products at (1.9) was in a rising and decreasing trend, and the accumulation was maximum at 67% PMS content, and barely detectable at PMS contents below 50%. However, when the PMS content is reduced to 50%, t _r (3.5) and t _r (4.2) two degradation products begin to occur and the accumulation increases as the amount of PMS decreases; t is t _r (7.6) variation is irregular, and the peak area is less than 150 when the PMS dosage is 1/2 or 2/3. Taken together, mnO ₂ The treatment effect is best when the mass ratio of the organic polymer to the PMS is 1:1, the degradation efficiency of OFX is high, and the generation and accumulation of degradation products can be inhibited.

Example 2

0.20g ofloxacin was used as degradation target, and 0.90g of various oxides of manganese (MnO) ₂ 、Mn ₃ O ₄ Or Mn of ₂ O ₃ ) Mixing with 0.90g PMS according to a mass ratio of 1:1, and degrading ofloxacin by adopting a synchronous mechanochemical method according to the steps 1-3. Experimental results show that after 60min of ball milling reaction, the degradation rate of the three combined systems to OFX is more than 90% (a in FIG. 2). B in fig. 2 counts the peak areas of the 5 main degradation products after 60min of the ball milling reaction. At MnO ₂ In the PMS system, four degradation products occur, t _r (2.2) and t _r The peak areas of the degradation products at (7.6) are all less than 100, at t _r (3.5) and t _r The peak areas of the degradation products at (4.2) were each around 60. At Mn ₂ O ₃ In the PMS system, t _r The peak area of the degradation product at (1.9) was 400, which is 2 times that of the PMS system, t _r The peak area of the product at (2.2) was 150. At Mn ₃ O ₄ In the PMS system, t _r The product peak area at (1.9) is 300, which is 1.5 times, t, that of the PMS system _r (2.2) and t _r The peak area of the degradation product at (7.6) is about100. In contrast, mn ₂ O ₃ PMS and Mn ₃ O ₄ In the PMS system, t _r (1.9) accumulation of highly polar degradation products was reduced, and MnO ₂ Pair t of PMS system _r The inhibition effect of the by-product at (1.9) is the best.

Example 3

0.20g of norfloxacin is taken as a degradation object, and 0.90g of MnO is added simultaneously ₂ And 0.90g PMS, and carrying out synchronous mechanochemical degradation experiments according to the steps 1 to 3. As can be seen from FIG. 3, in MnO ₂ When the amount of the norfloxacin and the PMS are both 0.90g, the norfloxacin is reacted for 30 minutes, the degradation rate of the norfloxacin is 93%, and four main degradation products are generated. With prolonged reaction time, the liquid chromatography retention time t is as follows _r (3.8) and t _r The degradation products at (8.9) degrade slowly, but t _r (1.9) and t _r Once the degradation products at (2.2) are formed, little degradation can be continued, resulting in gradual accumulation of degradation products, reaction to 30min, and the sum of chromatographic peak areas of the four products exceeds 500. Description the synchronous degradation method in example 2 encounters an obstacle in degrading norfloxacin, and in the early stage of the reaction, PMS and norfloxacin should be prevented from reacting as much as possible, and MnO should be used first ₂ And (3) degrading most of target substances, and then adding a small amount of PMS relay oxidation residual norfloxacin and accumulated weak-polarity byproducts, namely adding the grinding agent step by step to degrade.

Example 4

Taking 0.2g of norfloxacin as a degradation object, adding MnO in three steps ₂ Or PMS, carrying out step-by-step mechanochemical degradation experiments according to the steps 1-3. First, the MnO is added in the first step ₂ The mass of (2) is 0.50-1.20 g; next, examine the second step MnO ₂ The effect of the addition amount (0.50-1.50 g); finally, the effect of the amount of PMS added in the third step (0.30-1.00 g) was examined. The result is shown as a in FIG. 4, the first ball milling reaction is carried out for 10min with MnO ₂ When the addition amount is increased from 0.30 to 0.50g, the degradation rate of NOR is increased from 25% to 55%, and then MnO is continuously increased ₂ The amount of the grinding agent is 1.2g, and the degradation rate of the NOR is slowly increased to 60 percent. At the same time, at a liquid chromatography retention time t _r (3.8) and t _r At (8.9), two degradation products were observed, both of which increased in accumulation with increasing NOR degradation rate, and t _r (3.8) the cumulative amount of product at (c) is greater than t _r (8.9). Taken together, the MnO used in the first step ₂ The amount was 0.50g.

B in FIG. 4 shows MnO in the second step ₂ The effect of the amount of addition on the NOR degradation rate and the accumulation of degradation intermediates. If MnO is not added in the second step ₂ The degradation rate is not obviously improved (60.1 percent) after 10 minutes of mechanochemical reaction, the accumulation amount of byproducts is further increased, t _r (3.8) and t _r (8.9) peak areas were 489 and 68, respectively. Gradually increase MnO ₂ The addition amount is as MnO ₂ When the dosage is increased from 0.30g to 1.00g, the degradation rate of NOR after 10min of reaction is increased from 70.1% to 85.8%, if MnO is continuously increased ₂ The degradation rate of NOR is only increased by 0.3% when the dosage is 1.50 g. t is t _r (3.8) and t _r (8.9) degradation products still increased slowly with increasing BMP usage, but accumulated in a smaller amount than MnO was not added ₂ There is a significant decrease in time. Comprehensively consider, the second step is adding MnO ₂ The amount of (2) was 1.00g.

The effect of the amount of PMS added in the third step on NOR residue and accumulation of intermediate products is shown in fig. 4 c. If PMS is not added, the degradation rate is 89.8% after 10min of reaction, and the two byproducts hardly degrade. After 0.30g of PMS is added for ball milling for 10min, the degradation rate of NOR can reach 95.8%, t _r (3.8) and t _r The peak areas of degradation products at (8.9) decreased to around 98 and 80, respectively; when the PMS dosage is increased to 0.70g, the degradation rate of NOR reaches 100%, t _r (3.8) and t _r The peak areas of degradation products at (8.9) all decrease to 25; continuously increasing the PMS dosage, t _r The accumulation of degradation products at (3.8) is further reduced, t _r (8.9) the amount of degradation products is substantially unchanged, but at t _r (1.9) novel highly polar products are produced. The above results show that addition of an appropriate amount of PMS not only improves the degradation rate of NOR but also reduces accumulation of degradation intermediates, and in view of the overall, the amount of PMS to be used is preferably 0.70 g.

Example 5

And (3) adopting an escherichia coli bacteriostasis experiment to study toxicity changes before and after fluoroquinolone degradation. The oxidation effect of residual PMS affects the growth of e.coli, interfering with experimental results. Considering that PMS is indissolvable in ethanol, fluoroquinolone and degradation products can be extracted by adopting an ethanol extraction method, and simultaneously, the interference of PMS is eliminated. And (3) carrying out vacuum drying on the ethanol extract, adding distilled water with equal amount, and carrying out redissolution under the assistance of ultrasound to obtain a sample solution. MG 1655 colibacillus strain is inoculated in 5mL LB liquid medium and cultured for 6-8 h under the sterile environment of 37 ℃. 1mL of the bacterial liquid was taken and 19mL of physiological saline was added to obtain a bacterial liquid diluted 20-fold. LB agar medium was autoclaved and poured into plates, 20mL each, and kept at 37℃overnight. And transferring 550 mu L of diluted bacterial liquid into a flat plate, and uniformly coating. After the bacterial liquid is completely absorbed, 10 mu L of sample solution to be detected is removed, 3-5 samples are taken from each plate point, and the sample solution is dried and cultured for 12 hours at 37 ℃. If the degradation extract liquid inhibits the growth of bacteria, a bacteriostasis ring is generated around the liquid drop, and the diameter of the bacteriostasis ring is positively related to the bacteriostasis performance of the test liquid. The edge of the inhibition zone is limited by the fact that no obvious growth of bacteria is seen, the diameter of the completely inhibited zone is measured for a plurality of times, and the average value of the diameters is calculated.

MnO in comparative example 1 ₂ Changes in bacteriostatic toxicity before and after degrading ofloxacin, PMS and the combination of the two with the three grinding agent systems are shown in figure 5. From the graph, the diameters of the inhibition rings of the PMS system are respectively 0.86 cm, 0.52 cm and 0.48cm when the PMS system is degraded for 0, 5 and 60 min; mnO (MnO) ₂ The system is respectively 0.83cm, 0.66 cm and 0.62cm; mnO (MnO) ₂ The PMS-combined system was 0.87cm, 0.68cm and 0, respectively. As can be seen from the results of fig. 1, the PMS system is capable of completely degrading ofloxacin, but the degradation products still have antibacterial properties; mnO (MnO) ₂ The system residual plenty of ofloxacin is a main source of bacteriostasis; the combined system of the two can completely eliminate the antibacterial capability of the target and the product.

In order to examine the effect of the step-wise mechanochemical treatment of NOR, 0.50g of MnO was used in the first to third steps, respectively, with reference to the experimental method of example 4 ₂ 、1.00g MnO ₂ And 0.70g PMS, each reaction time was 10min. As shown in FIG. 6, the diameter of the antibacterial ring produced by norfloxacin is 1.89cm before the reaction starts, and the first to third stepsAfter the degradation is finished, the diameter of the inhibition ring is reduced to 1.79cm, 0.83cm and 0 in sequence. This shows that stepwise degradation can gradually weaken the antibacterial ability of norfloxacin, and finally complete elimination is achieved.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. A method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical method is characterized in that manganese oxide and persulfate are adopted as grinding agents, the grinding agents are added into a ball milling tank containing fluoroquinolone to be treated step by step for ball milling, the step addition is that firstly manganese oxide is added and then persulfate is added, and the manganese oxide is added in batches; lattice oxygen and active species generated by the grinding agent in the ball milling process oxidize and degrade fluoroquinolone;

the mechanical force generated in the ball milling process activates the manganese oxide and the persulfate; the manganese oxide is activated by mechanical force effect to release active lattice oxygen; persulfate is catalytically activated by mechanical force effects and manganese oxides to produce reactive oxygen species.

2. The method for degrading fluoroquinolone using manganese oxide and persulfate mechanochemical process as recited in claim 1, wherein the reactive oxygen species are sulfate radicals, hydroxyl radicals, and singlet oxygen.

3. The method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical process as recited in claim 1, wherein the manganese oxide is MnO ₂ 、Mn ₂ O ₃ 、Mn ₃ O ₄ And at least one of MnO.

4. The method for degrading fluoroquinolone using a manganese oxide and persulfate mechanochemical process as set forth in claim 3, wherein theMnO ₂ Is alpha-MnO ₂ 、β-MnO ₂ 、γ-MnO ₂ 、ε-MnO ₂ And delta-MnO ₂ At least one of them.

5. The method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical process as recited in claim 1, wherein the persulfate is potassium peroxymonosulfate, sodium peroxymonosulfate, potassium peroxydisulfate, or sodium peroxydisulfate.

6. The method for degrading fluoroquinolone using manganese oxide and persulfate mechanochemical process as recited in claim 1, wherein the fluoroquinolone is at least one of ofloxacin, norfloxacin, ciprofloxacin, pefloxacin, and enoxacin.

7. The method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical process as recited in claim 1, wherein the mass ratio of the grinding agent to fluoroquinolone is 20:1 to 5:1.

8. The method for degrading fluoroquinolone by using manganese oxide and persulfate mechanochemical process as claimed in claim 1, wherein the mass ratio of manganese oxide to persulfate in the grinding agent is 5:1 to 1:5.