Preparation method and application of ZIF-67 loaded coal gangue composite material

Abstract

The present invention discloses a preparation method and application of a ZIF-67 loaded coal gangue composite material. First, the waste coal gangue is pretreated; 2-methylimidazole is added to deionized water for dissolution, and after the dissolution, the pretreated coal gangue is added for reaction; after the reaction, Co(NO 3 ) 2 6H 2 O, continue the in-situ growth reaction at the same reaction temperature; after the reaction, filter, wash and dry the resulting mixed solution in turn, and obtain a coal gangue composite material loaded with ZIF-67 after drying. Through the present invention, ZIF-67 can be successfully loaded on coal gangue, effectively avoiding the difficulty of recycling and non-reusability of ZIF-67, and can quickly and efficiently remove antibiotic pollutants in wastewater; and can effectively activate peroxymonosulfate to degrade antibiotic pollutants in aqueous solutions, while expanding the application of coal gangue in the field of water treatment.

Description

1. Technical field:

[0001] The invention relates to the technical field of environmental wastewater treatment, and in particular to a preparation method and application of a ZIF-67 loaded coal gangue composite material. 2. Background technology:

[0002] Tetracycline hydrochloride (TC) is a broad-spectrum antibiotic that is effective in treating infectious diseases in humans and veterinary medicine and is therefore widely used. The widespread use of TC in medical treatment has also led to a significant increase in the discharge of discarded and expired tetracycline hydrochloride drugs, unabsorbed tetracycline hydrochloride (20-97%) in the human (or animal) body, and drug metabolites. Due to the accumulation of emerging pollutants in the natural environment, the widespread use of tetracycline hydrochloride (TC) in personal medical treatment has brought potential risks to the aquatic environment and human health.

[0003] At present, there are many methods for the degradation and removal of tetracycline hydrochloride. For example: 1) Biological treatment technology: This treatment technology requires a series of complex physical, chemical and biological processes, including volatilization, photodegradation, precipitation, substrate adsorption, hydrolysis, plant absorption and accumulation, as well as microbial degradation and simultaneous removal of antibiotics in water (such as artificial wetlands). 2) Advanced oxidation technology approach: There are currently studies on the degradation of TC based on persulfate advanced oxidation technology. During the treatment process, biochar, various composites, minerals, etc. can be used as catalytic materials, and a certain oxidant (such as persulfate) is added to produce a redox reaction to act on TC, which is eventually degraded into water and carbon dioxide. 3) Photocatalytic degradation method: In a water environment, the action of light energy and catalytic materials produces highly active free radicals such as OH, which eventually degrade antibiotics into carbon dioxide, water and other small molecules through multiple stages. The selection of photocatalyst materials plays a key role in the degradation of antibiotics, such as perovskite, molybdenum disulfide, etc. as photocatalytic materials. 4) Adsorption: Select materials with large specific surface area and porosity to combine antibiotics with adsorbent materials through electrostatic interaction, coordination, hydrogen bonding and other forces to achieve the purpose of removing pollutants from water. The adsorption mechanism of the adsorbent is mainly related to the adsorbent itself and the properties of the antibiotic.

[0004] In summary, since the migration of antibiotics in the environment is limited by their own physical and chemical properties and water environment conditions, the abundance of microbial flora in the biological treatment system is low, so the adsorption and microbial treatment effects in the biological treatment antibiotic system are limited; photocatalytic degradation uses light as energy, and catalyst materials often have problems such as low light source utilization and easy recombination of photogenerated carriers; adsorption is affected by the specific surface area and surface properties of the adsorbent. The adsorbent after adsorption is difficult to recycle, the recovery efficiency is poor, and the application is limited. Advanced oxidation technology produces active substances by activating oxidants, and is not limited by external conditions (such as light, pH) and other water environment conditions. It has the advantages of fast reaction rate, wide application range, and basically no pollution. It is particularly important to find cheap and easily available base materials and select catalytic materials with simple synthesis process and high yield.

[0005] In the field of water treatment and degradation of pollutants, transition metals such as cobalt, iron, copper, manganese and their oxides have become the main substances for activating oxidants such as PMS and PS. Zeolite imidazolate framework (ZIF) is a subclass branch of metal organic framework (MOF), and ZIFs are usually synthesized by 2-methylimidazole organic ligands and transition metal ions. ZIF-67 is difficult to recycle due to its own nanoparticle size; the electron transport capacity of the material itself is weak. Therefore, it is particularly important to find a carrier with a large specific surface area and rich surface properties. Natural coal gangue (CG) is a widespread by-product produced during coal mining or washing in the coal industry. It is a waste coal-related waste and is commonly found near coal mines or related enterprises. CG is usually black-gray rock with rich minerals, organic matter and stable crystals. Many studies have shown that coal gangue has potential application value in water treatment. The surface of coal gangue is flat and the structure is rich. Therefore, the present invention explores the generation of ZIF-67 by in-situ loading on CG, and uses this composite material in the field of water treatment to realize the resource utilization of coal gangue solid waste. 3. Summary of the invention:

[0006] The technical problem to be solved by the present invention is: according to the development status of existing antibiotic wastewater treatment technology, in order to study the demand for a carrier with large specific surface area and rich surface properties for ZIF-67 composite materials, the present invention provides a preparation method and application of a ZIF-67 loaded coal gangue composite material. Through the technical scheme of the present invention, the recyclability and reusability of ZIF-67 can be improved, and peroxymonosulfate PMS can be effectively activated to degrade antibiotic pollutants in aqueous solutions, while expanding the application of coal gangue in the field of water treatment.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is:

[0008] The present invention provides a method for preparing a ZIF-67 loaded coal gangue composite material, the preparation method comprising the following steps:

[0009] a. Pretreatment of coal gangue: The waste coal gangue is dried and crushed in sequence, passed through a 120-mesh sieve, and the sieve is ultrasonically cleaned (the cleaning time is 10 minutes to remove impurities in the coal gangue). After cleaning, it is centrifugally filtered and dried in sequence to obtain pretreated coal gangue;

[0010] b. First, 2-methylimidazole is added to deionized water for dissolution, and pretreated coal gangue is added to the resulting solution for reaction at a temperature of 25 to 35°C for 5 to 8 minutes. After the reaction, Co(NO3)2·6H2O is added, and the in-situ growth reaction is continued at this temperature for 30 to 40 minutes. After the reaction, the resulting mixed solution is filtered, washed, and dried in sequence, and then ground and dispersed after drying to obtain a coal gangue composite material loaded with ZIF-67.

[0011] According to the preparation method of the ZIF-67 loaded coal gangue composite material, in the drying and crushing process of step a, the drying is carried out in an oven, the drying temperature is 40 to 45° C., and the drying time is 8 to 12 hours;

[0012] During the centrifugal filtration and drying process, the drying is carried out in a constant temperature dryer, the drying temperature is 35-40° C., and the drying time is 5-8 hours.

[0013] According to the preparation method of the ZIF-67 loaded coal gangue composite material, the mass ratio of the pretreated coal gangue, 2-methylimidazole and Co(NO3)2·6H2O in step b is 0.15:0.08~1.7:0.04~1;

[0014] When the 2-methylimidazole is added into deionized water for dissolution, the mass volume ratio of the 2-methylimidazole to the deionized water is 1.6-34 g:1 L.

[0015] According to the above-mentioned preparation method of the ZIF-67 loaded coal gangue composite material, the filtration in step b is performed by using a vacuum filtration pump, and the vacuum filtration pump is equipped with a 0.45 μm organic filtration membrane.

[0016] In addition, the invention provides an application of the prepared ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater.

[0017] According to the above-mentioned application of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater, in the application process of antibiotic wastewater degradation, the ZIF-67 loaded coal gangue composite material is used as a catalyst and permonosulfate is used as an oxidant, and the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0018] According to the above-mentioned application of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater, during the application, the reaction system is 100mL of wastewater, the concentration of the ZIF-67 loaded coal gangue composite material is 100mg / L, the concentration of permonosulfate is 1mmol / L, and the concentration of antibiotic is 20mg / L.

[0019] According to the above application of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater, the antibiotic is tetracycline hydrochloride.

[0020] The positive beneficial effects of the present invention are:

[0021] 1. The ZIF-67 loaded coal gangue composite material prepared by the present invention effectively solves the shortcomings of small particle size and weak electron transfer of ZIF-67.

[0022] First, the coal gangue loaded with ZIF-67 has a large particle size and can be separated by filtration after the reaction, which is easy to operate and improves the recovery efficiency. Secondly, the present invention first discovered that the Fe element in the coal gangue can also participate in the activation of PMS. After the reaction, Fe element is precipitated in the solution and the iron content of the composite material before and after the reaction increases from 0.39% to 2.63%. The valence state of iron changes from the compound state to Fe 2+ , Fe 3+ Peak value (see attached Figure 5 and attached Figure 6 ); the presence of Fe and Co synergistically degrade pollutants, accelerate the reaction process, and improve the reaction efficiency; finally, the hydroxyl radicals on the surface of coal gangue also have an activation effect on PMS. Therefore, the present invention expands the applicability of coal gangue in advanced oxidation of water treatment.

[0023] 2. The present invention has been proved through application tests that coal gangue can be used as a good carrier of ZIF-67 and as a catalyst in water treatment. In the synthesis process, the loading amount of ZIF-67 on coal gangue is adjusted by changing the dosage of 2-methylimidazole and Co(NO3)2·6H2O, and coal gangue composite materials with different ZIF-67 loading amounts are synthesized for catalytic degradation of TC. Experiments have proved that the above materials have a good degradation effect on TC.

[0024] 3. The technical solution of the present invention uses a ZIF-67 coal gangue composite material to activate persulfate to catalyze the degradation of tetracycline hydrochloride, proving that the degradation process is resistant to the interference of solution pH changes and the presence of anions, and the degradation effect is significant and efficient.

[0025] 4. The technical solution of the present invention uses coal gangue as raw material, which has the advantages of large output, low cost and easy availability; the coal gangue pretreatment and composite material synthesis process in the solution of the present invention are simple. The coal gangue pretreatment can be used after crushing, screening, simple cleaning and drying; the composite material can be synthesized at room temperature, and the reaction can be completed by adding drugs and stirring. 4. Description of the drawings:

[0026] Figure 1 The degradation result of tetracycline hydrochloride by the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention;

[0027] Figure 2 The degradation results of tetracycline hydrochloride under different pH conditions for the ZIF-67 coal gangue composite material prepared in Example 1 of the present invention;

[0028] Figure 3 The degradation results of tetracycline hydrochloride by the ZIF-67 coal gangue composite material prepared in Example 1 of the present invention under the interference of different anions;

[0029] Figure 4 A diagram showing the effect of different quenchers on the degradation of tetracycline hydrochloride in the ZIF-67 coal gangue composite material prepared in Example 1 of the present invention.

[0030] Figure 5 Fe 2p fine spectrum measured by XPS of the ZIF-67 gangue composite material loaded with ZIF-67 prepared in Example 1 of the present invention before TC degradation reaction.

[0031] Figure 6 Fe 2p fine spectrum measured by XPS of the ZIF-67 gangue composite material loaded with the prepared Example 1 of the present invention after TC degradation reaction. V. Specific implementation methods:

[0032] The present invention is further described below in conjunction with embodiments, but the protection scope of the technical solution of the present invention is not limited thereto.

[0033] Embodiment 1:

[0034] The preparation method of the ZIF-67 loaded coal gangue composite material of the present invention comprises the following detailed steps:

[0035] a. Pretreatment of coal gangue: Place the waste coal gangue in an oven and dry it at 45°C for 12 hours, then crush it with a jaw crusher, pass it through a 120-mesh sieve after crushing, and ultrasonically clean the sieve for 10 minutes (to remove impurities in the coal gangue), centrifuge it after cleaning, and dry it in a constant temperature dryer after filtration at a drying temperature of 40°C and a drying time of 5 hours; grind and disperse it after drying to obtain pretreated coal gangue;

[0036] b. First, 0.164 g of 2-methylimidazole was added to 50 mL of deionized water for dissolution. After dissolution, 150 mg of pretreated coal gangue was added to the obtained solution for stirring reaction (stirring speed was 300 rpm), the reaction temperature was 30°C, and the reaction time was 5 min; after the reaction, 0.096 g of Co(NO3)2·6H2O was added, and stirring was continued at this temperature for in-situ growth reaction, and the reaction time was 30 min; after the reaction, the obtained mixed solution was filtered using a vacuum filtration pump (the vacuum filtration pump was equipped with a 0.45 μm organic filter membrane), and after filtration, it was washed three times with deionized water, and finally dried in a vacuum drying oven at a drying temperature of 45°C and a drying time of 5 h. After drying, a coal gangue composite material loaded with ZIF-67 (ZIF-67 / CG) was obtained.

[0037] Embodiment 2:

[0038] The preparation method of the ZIF-67 loaded coal gangue composite material of the present invention comprises the following detailed steps:

[0039] a. Pretreatment of coal gangue: Place the waste coal gangue in an oven and dry it at 40°C for 12 hours, then crush it with a jaw crusher, pass it through a 120-mesh sieve after crushing, and ultrasonically clean the sieve for 10 minutes (to remove impurities in the coal gangue), centrifuge it after cleaning, and dry it in a constant temperature dryer after filtration at a drying temperature of 35°C and a drying time of 8 hours; grind and disperse it after drying to obtain pretreated coal gangue;

[0040] b. First, 0.082 g of 2-methylimidazole was added to 50 mL of deionized water for dissolution. After dissolution, 150 mg of pretreated coal gangue was added to the resulting solution for stirring reaction (stirring speed was 300 rpm), the reaction temperature was 28 ° C, and the reaction time was 5 min; after the reaction, 0.483 g of Co(NO3)2·6H2O was added, and stirring was continued at this temperature for in-situ growth reaction, and the reaction time was 35 min; after the reaction, the resulting mixed solution was filtered using a vacuum filtration pump (the vacuum filtration pump was equipped with a 0.45 μm organic filter membrane), and after filtration, it was washed three times with deionized water, and finally dried in a vacuum drying oven at a drying temperature of 45 ° C and a drying time of 5 h. After drying, a coal gangue composite material loaded with ZIF-67 (ZIF-67 / CG) was obtained.

[0041] Embodiment 3:

[0042] The preparation method of the ZIF-67 loaded coal gangue composite material of the present invention comprises the following detailed steps:

[0043] a. Pretreatment of coal gangue: Place the waste coal gangue in an oven and dry it at 43°C for 12 hours, then crush it with a jaw crusher, pass it through a 120-mesh sieve after crushing, and ultrasonically clean the sieve for 10 minutes (to remove impurities in the coal gangue), centrifuge it after cleaning, and dry it in a constant temperature dryer after filtration at a drying temperature of 38°C and a drying time of 5 hours; grind and disperse it after drying to obtain pretreated coal gangue;

[0044] b. First, 1.64 g of 2-methylimidazole was added to 50 mL of deionized water for dissolution. After dissolution, 150 mg of pretreated coal gangue was added to the obtained solution for stirring reaction (stirring speed was 300 rpm), the reaction temperature was 32 ° C, and the reaction time was 5 min; after the reaction, 0.966 g of Co(NO3)2·6H2O was added, and stirring was continued at this temperature for in-situ growth reaction, and the reaction time was 40 min; after the reaction, the obtained mixed solution was filtered using a vacuum filtration pump (the vacuum filtration pump was equipped with a 0.45 μm organic filter membrane), and after filtration, it was washed three times with deionized water, and finally dried in a vacuum drying oven at a drying temperature of 45 ° C and a drying time of 5 h. After drying, a coal gangue composite material loaded with ZIF-67 (ZIF-67 / CG) was obtained.

[0045] The present invention provides an example of application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 in the degradation of antibiotic wastewater.

[0046] Application Example 1:

[0047] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 as a catalyst and peroxymonosulfate as an oxidant, and using the advanced oxidation technology based on sulfate free radicals and singlet oxygen to degrade antibiotic wastewater. The specific operation is as follows:

[0048] 100mL of tetracycline hydrochloride TC wastewater (the concentration of the wastewater is 20mg / L) is added to a 200mL conical flask, and then the prepared ZIF-67 coal gangue composite material and peroxymonosulfate prepared in Example 1 are added, and the concentration of the ZIF-67 coal gangue composite material after addition is 100mg / L, and the concentration of peroxymonosulfate is 1mmol / L; then degradation is carried out in a constant temperature water bath oscillator, the contact temperature is 25°C, the oscillation speed is 120rpm, sampling is carried out at different reaction times, and the concentration of tetracycline hydrochloride is measured at 375nm of an ultraviolet spectrophotometer. The natural pH of the tetracycline hydrochloride solution is 6.2.

[0049] The above analysis results are detailed in the attached Figure 1 , by the attached Figure 1It can be seen that after 15 minutes of using ZIF-67 / CG to activate permonosulfate to degrade tetracycline hydrochloride, the removal rate of tetracycline hydrochloride was as high as 98.6%, which proves that ZIF-67 / CG activated permonosulfate has a significant effect on the treatment of tetracycline hydrochloride wastewater.

[0050] Application Example 2:

[0051] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0052] The pH value of 100 ml TC wastewater (the concentration of TC in the wastewater is 20 mg / L) was adjusted to 3 using 0.1 mol / L NaOH and 0.1 mol / L H2SO4 in a small volume range. Then 100 mg / L ZIF-67 / CG and 1 mM permonosulfate were added in sequence. The degradation study was carried out in a constant temperature water bath oscillator with a contact temperature of 25°C and an oscillation speed of 120 rpm. Samples were taken at different reaction times and the concentration of tetracycline hydrochloride was measured at 375 nm using a UV spectrophotometer.

[0053] Application Example 3:

[0054] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0055] The pH value of 100 ml TC wastewater (the concentration of TC in the wastewater is 20 mg / L) was adjusted to 9 by using 0.1 mol / L NaOH and 0.1 mol / L H2SO4 in a small volume range. Then 100 mg / L ZIF-67 / CG and 1 mM permonosulfate were added in sequence. The degradation study was carried out in a constant temperature water bath oscillator with a contact temperature of 25°C and an oscillation speed of 120 rpm. Samples were taken at different reaction times and the concentration of tetracycline hydrochloride was measured at 375 nm using an ultraviolet spectrophotometer.

[0056] Application Example 4:

[0057] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0058] The pH value of 100 ml TC wastewater (the concentration of TC in the wastewater is 20 mg / L) was adjusted to 11 by using 0.1 mol / L NaOH and 0.1 mol / L H2SO4 in a small volume range. Then 100 mg / L ZIF-67 / CG and 1 mM permonosulfate were added in sequence. The degradation study was carried out in a constant temperature water bath oscillator with a contact temperature of 25°C and an oscillation speed of 120 rpm. Samples were taken at different reaction times and the concentration of tetracycline hydrochloride was measured at 375 nm using a UV spectrophotometer.

[0059] The processing results of the present invention's application examples 1-4 are shown in the attached Figure 2 As shown, when the pH value of TC wastewater ranges from 3 to 11, the TC degradation efficiency remains above 90%, and the degradation efficiencies are 92.3%, 98.6%, 99.0%, and 99.7%, respectively, proving that the ZIF-67 / CG composite material prepared by the present invention has high catalytic activity and a wide range of pH applicability. In addition, there is a slight increase at pH = 11, proving that strong alkaline conditions are conducive to the catalytic reaction.

[0060] Application Example 5:

[0061] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0062] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 20 mM sodium sulfate was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of sulfate in the solution on the degradation of pollutants. The contact temperature of the water bath oscillator was 25 ° C and the oscillation speed was 120 rpm. Samples were taken at different reaction times, and the concentration of tetracycline hydrochloride was measured at 375 nm on a UV spectrophotometer.

[0063] Application Example 6:

[0064] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0065] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 20 mM sodium chloride was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of chloride ions in the solution on the degradation of pollutants. The contact temperature of the water bath oscillator was 25 ° C and the oscillation speed was 120 rpm. Samples were taken at different reaction times, and the concentration of tetracycline hydrochloride was measured at 375 nm on a UV spectrophotometer.

[0066] Application Example 7:

[0067] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0068] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 20 mM sodium nitrate was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of nitrate in the solution on the degradation of pollutants. The contact temperature of the water bath oscillator was 25 ° C and the oscillation speed was 120 rpm. Samples were taken at different reaction times, and the concentration of tetracycline hydrochloride was measured at 375 nm on a UV spectrophotometer.

[0069] Application Example 8:

[0070] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0071] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 20 mM sodium dihydrogen phosphate was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of dihydrogen phosphate in the solution on the degradation of pollutants. The contact temperature of the water bath oscillator was 25 ° C and the oscillation speed was 120 rpm. Samples were taken at different reaction times, and the concentration of tetracycline hydrochloride was measured at 375 nm on a UV spectrophotometer.

[0072] Application Example 9:

[0073] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0074] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 20 mM sodium bicarbonate was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of bicarbonate in the solution on the degradation of pollutants. The contact temperature of the water bath oscillator was 25 ° C and the oscillation speed was 120 rpm. Samples were taken at different reaction times, and the concentration of tetracycline hydrochloride was measured at 375 nm on a UV spectrophotometer.

[0075] The results of the treatment of the present invention in Examples 5-9 are shown in the attached Figure 3 .Depend on Figure 3 It can be seen that under different anion NO3 - , Cl - 、HCO3 - 、H2PO4 - and SO4 2- Under the influence of , the removal efficiency of tetracycline hydrochloride was 98.8%, 91.2%, 91.0%, 98.9% and 97.8%, respectively, which proved that the activation ability of the ZIF-67 / CG composite material prepared by the present invention was not greatly disturbed under the interference of high concentration anions, and it still had a good degradation effect on tetracycline hydrochloride.

[0076] Application Example 10:

[0077] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0078] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 1000 mM methanol solution was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the quenching of ·OH, ·SO4 by methanol. - The effect on the degradation of pollutants was analyzed by using a liquid chromatograph, and the contact temperature of the water bath oscillator was 25 °C and the oscillation speed was 120 rpm. Samples were taken at different times of the reaction, and the concentration of tetracycline hydrochloride was detected by using a liquid chromatograph.

[0079] Application Example 11:

[0080] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0081] 100ml TC wastewater with a concentration of 20mg / L and a pH value of 6.2 was added to a 200mL conical flask, and then 1000mM tert-butanol solution was added. After sufficient dissolution, 100mg / L ZIF-67 / CG composite material and 1mM permonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of tert-butanol quenching ·OH on the degradation of pollutants. The contact temperature of the water bath oscillator was 25℃ and the stirring speed was 120rpm. Samples were taken at different times of the reaction, and the concentration of tetracycline hydrochloride was measured using a liquid chromatograph.

[0082] Application Example 12:

[0083] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0084] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 200 mM furfuryl alcohol solution was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM peroxymonosulfate were added in sequence, and degradation was carried out in a constant temperature water bath oscillator to study the effect of furfuryl alcohol quenching. 1 Effect of O2 on the degradation of pollutants. The contact temperature of the water bath oscillator was 25°C and the stirring speed was 120 rpm. Samples were taken at different times of the reaction and the concentration of tetracycline hydrochloride was measured using a liquid chromatograph.

[0085] Application Example 13:

[0086] The application of the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention in the degradation of antibiotic wastewater, using the ZIF-67 loaded coal gangue composite material prepared in Example 1 of the present invention as a catalyst and permonosulfate as an oxidant, the antibiotic wastewater is degraded by advanced oxidation technology based on sulfate free radicals and singlet oxygen.

[0087] 100 ml of TC wastewater with a concentration of 20 mg / L and a pH value of 6.2 was added to a 200 mL conical flask, and then 1.2 mM p-benzoquinone solution was added. After sufficient dissolution, 100 mg / L of ZIF-67 / CG composite material and 1 mM permonosulfate were added in sequence. The degradation was carried out in a constant temperature water bath oscillator to study the quenching of p-benzoquinone·O2 - The effect on the degradation of pollutants was measured by using a liquid chromatograph, with the contact temperature of the water bath oscillator being 25 °C and the stirring speed being 120 rpm. Samples were taken at different times of the reaction, and the concentration of tetracycline hydrochloride was measured by using a liquid chromatograph.

[0088] The processing results of the application examples 10-13 of the present invention are detailed in the attached Figure 4 .Depend on Figure 4 It can be seen that methanol, tert-butyl alcohol, furfuryl alcohol, and p-benzoquinone all have an inhibitory effect on the degradation of pollutants, with the inhibitory effects reaching 35.3%, 8.5%, 70%, and 9.3%, respectively, proving that SO4 - , 1 O2 plays a major role in catalytic degradation. The process of activating peroxymonosulfate to degrade tetracycline hydrochloride by the ZIF-67 / CG composite material prepared by the present invention includes free radical and non-free radical pathways.

Claims

1. A method for preparing a ZIF-67 loaded coal gangue composite material, characterized in that: The preparation method comprises the following steps: a. Pretreatment of coal gangue: the waste coal gangue is dried and crushed in sequence, passed through a 120-mesh sieve, the sieve under the sieve is ultrasonically cleaned, and after cleaning, centrifugal filtration and drying are performed in sequence to obtain pretreated coal gangue; b. First, 2-methylimidazole is added to deionized water for dissolution, and the pretreated coal gangue is added to the solution obtained after dissolution for reaction, the reaction temperature is 25-35°C, and the reaction time is 5-8 minutes; after the reaction, Co(NO3)2⋅6H2O is added, and the in-situ growth reaction is continued at this temperature for 30-40 minutes; after the reaction, the obtained mixed solution is filtered, washed, and dried in sequence, and then ground and dispersed after drying to obtain a coal gangue composite material loaded with ZIF-67; The mass ratio of the pretreated coal gangue, 2-methylimidazole and Co(NO3)2⋅6H2O is 0.15:0.08-1.7:0.04-1.

2. The method for preparing the ZIF-67 loaded coal gangue composite material according to claim 1, characterized in that: In the drying and crushing process of step a, the drying is carried out in an oven at a drying temperature of 40 to 45° C. and a drying time of 8 to 12 hours; During the centrifugal filtration and drying process, the drying is carried out in a constant temperature dryer, the drying temperature is 35-40° C., and the drying time is 5-8 hours.

3. The method for preparing the ZIF-67 loaded coal gangue composite material according to claim 1, characterized in that: When the 2-methylimidazole in step b is added to deionized water for dissolution, the mass volume ratio between 2-methylimidazole and deionized water is 1.6-34 g:1 L.

4. The method for preparing the ZIF-67 loaded coal gangue composite material according to claim 1, characterized in that: The filtration in step b is performed using a vacuum filtration pump, and the vacuum filtration pump is equipped with a 0.45 μm organic filter membrane.

5. Use of the ZIF-67 loaded coal gangue composite material prepared according to claim 1 in the degradation of antibiotic wastewater.

6. The use of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater according to claim 5, characterized in that: In the application process of antibiotic wastewater degradation, the antibiotic wastewater is degraded by using the loaded ZIF-67 coal gangue composite material as a catalyst and peroxymonosulfate as an oxidant, and an advanced oxidation technology based on sulfate free radicals and singlet oxygen.

7. The use of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater according to claim 6, characterized in that: In the application, the reaction system is 100 mL of wastewater, the concentration of the loaded ZIF-67 coal gangue composite material is 100 mg / L, the concentration of permonosulfate is 1 mmol / L, and the concentration of antibiotics is 20 mg / L.

8. The use of the ZIF-67 loaded coal gangue composite material in the degradation of antibiotic wastewater according to claim 5, characterized in that: The antibiotic is tetracycline hydrochloride.

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