阅读说明：本技术 一种磁悬浮3d臭氧催化微球的制备及其在养殖污水中的应用 (Preparation of magnetic suspension 3D ozone catalytic microspheres and application thereof in aquaculture sewage ) 是由 肖艳春 黄婧 陈彪 于 2020-07-28 设计创作，主要内容包括：本发明属于污水处理技术领域,具体涉及一种磁悬浮3D臭氧催化微球的制备及其在矿化养殖污水中抗生素上的应用。本发明首先以CS、PVDF与Fe<Sub>3</Sub>O<Sub>4</Sub>等为原料,采用反相悬浮法制备微球载体,然后通过化学螯合作用结合催化活性金属组分来获得具有催化臭氧氧化功能的3D微球。该微球在自然状态下具有良好的悬浮稳定性,随臭氧O<Sub>3</Sub>微气泡匀速转动,增加了与抗生素和O<Sub>3</Sub>的接触面积,有效促进了微球表面的O<Sub>3</Sub>分解为高活性自由基(羟基自由基·OH和/或超氧自由基·O<Sub>2</Sub><Sup>-</Sup>),进而加快了养殖污水中抗生素的矿化速率和效率,提高了O<Sub>3</Sub>利用率；同时该磁性微球可通过外加磁场进行回收,具有较高的应用价值。(The invention belongs to the technical field of sewage treatment, and particularly relates to preparation of magnetic suspension 3D ozone catalytic microspheres and application of the magnetic suspension 3D ozone catalytic microspheres to antibiotics in mineralized aquaculture sewage. The invention firstly uses CS, PVDF and Fe 3 O 4 And the like as raw materials, preparing a microsphere carrier by adopting an inverse suspension method, and then combining a catalytic active metal component through chemical chelation to obtain the 3D microsphere with the catalytic ozonation function. The microsphere has good suspension stability in natural state and can be mixed with ozone O 3 The micro-bubbles rotate at a constant speed, and the micro-bubbles are added with antibiotics and O 3 The contact area of the microspheres effectively promotes the O on the surfaces of the microspheres 3 Decomposed into highly active free radicals (hydroxyl free radical. OH and/or superoxide free radical. O) 2 ‑ ) Further quickening the mineralization rate and efficiency of antibiotics in the aquaculture sewage and improving O 3 Utilization rate; meanwhile, the magnetic microspheres can be recycled through an external magnetic field, and have high application value.)

1. A magnetic suspension 3D ozone catalysis microsphere which is characterized in that: mixing chitosan CS, polyvinylidene fluoride PVDF and magnetic Fe₃O₄The nano particles are compounded to prepare a microsphere carrier, and then the microsphere with the function of catalyzing ozone oxidation is obtained by combining chemical chelation with a catalytic active component.

2. The magnetic suspension 3D ozone catalytic microsphere of claim 1, wherein: the catalytically active component is selected from the group consisting of a combination of at least one lanthanide metal component, at least one group VIIB metal component and at least one group VIII metal component.

3. The magnetic suspension 3D ozone catalytic microsphere of claim 2, wherein: the catalytic active components are cerium Ce, manganese Mn and cobalt Co.

4. A method for preparing magnetic suspension 3D ozone catalytic microspheres according to any one of claims 1 to 3, wherein the method comprises the following steps: the method comprises the following specific steps:

(1) weighing a certain amount of CS to dissolve in 2.0wt% acetic acid aqueous solution, 3.0wtThe percentage of chitosan acetic acid aqueous solution is recorded as light yellow sol A; dissolving 15.0g PVDF powder in 100mL N, N-dimethylacetamide DMAC, adding 5.0g polyvinylpyrrolidone PVP, mechanically stirring at 60 deg.C for 1d, and standingDefoaming to obtain casting solution B;

(2) respectively weighing 8mM trisodium citrate, 4mM ferric chloride hexahydrate and 12mM urea, dissolving in 80mL deionized water, adding 0.6g polyacrylamide and 0.3g polyethylene glycol, transferring the solution into a reaction kettle for high-temperature reaction, filtering, washing and drying to obtain magnetic Fe₃O₄Nanoparticles;

(3) uniformly mixing the sol A and the casting solution B, and then mixing the sol A and the casting solution B with Fe₃O₄Compounding magnetic nano particles, and carrying out ultrasonic reaction for 30 min; slowly adding into an organic phase consisting of 160mL of liquid paraffin and 8mL of Span-80 under stirring, and fully stirring for 30min at normal temperature to obtain a microsphere carrier; then sequentially adding 0.5wt10mL of glutaraldehyde solution and 30mL of mixed solution containing cerium nitrate, manganese nitrate and cobalt nitrate, continuously stirring, chemically crosslinking for 12h, filtering, and repeatedly cleaning with deionized water and absolute ethyl alcohol; then placing the mixture into NaOH solution with the pH of 9-10 for curing reaction for 2 hours, taking out the mixture, and repeatedly washing the mixture with deionized water until the mixture is neutral; and finally, drying the microspheres in a vacuum drying oven at 60 ℃ for 8 hours to obtain the microspheres.

5. The method of claim 4, wherein: the high-temperature reaction in the step (2) is specifically carried out in a vacuum drying oven at the temperature of 200-300 ℃ for 8-10 h.

6. The method of claim 4, wherein: the sol A, the casting solution B and magnetic Fe in the step (3)₃O₄The mass ratio of the nanoparticles is (2-8): (4.5-7.5): 1-4).

7. The preparation method according to claim 4, wherein in the ultrasonic reaction in the step (3), the ultrasonic frequency is 40-60 HZ.

8. The method of claim 4, wherein: based on the weight of the carrier, the content ratio of the catalytic active components Ce, Mn and Co is (1-2)wt%:(6～10)wt%:(5～8)wt%。

9. Use of a magnetically levitated 3D ozone catalytic microsphere of claim 1 in catalyzing an antibiotic in ozone-mineralized aquaculture wastewater.

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to a magnetic suspension 3D ozone catalytic microsphere, a preparation method and application thereof, which are further used for catalyzing O₃Application of antibiotics in mineralized culture sewage.

Background

China is the world's largest antibiotic producing and consuming country, producing about 21 million antibiotics each year, of which 46.1% are used in livestock and poultry farming. Antibiotics entering the bodies of livestock and poultry are difficult to be completely absorbed by organisms, and about 30-90% of antibiotics can be discharged out of the bodies of livestock and poultry along with excrement and urine in the form of parent bodies or active metabolites. Due to the fact that the antibiotics have strong stability and are difficult to degrade, a plurality of antibiotics still remain in the biogas slurry after anaerobic fermentation, the content of the antibiotics is high, the tetracycline and the sulfonamide antibiotics exist, and the content reaches dozens of to hundreds of ug/L. Biogas slurry as a high-quality and high-efficiency pollution-free organic fertilizer is applied to the production of various crops, but if the biogas slurry is directly irrigated, antibiotics in the biogas slurry can enable some microorganisms to generate resistance genes which can be transmitted in the environment, so that some pathogenic bacteria can generate resistance to medicines, and further, the ecological system and the human health are threatened more. Therefore, the method for rapidly and efficiently removing antibiotics in biogas slurry and simultaneously retaining nutrients (TN, TP and TK) is urgently found.

At present, the removal methods of antibiotics mainly comprise a biological method, an adsorption method and an oxidation method. The biological method has a long treatment period, and meanwhile, due to the difficult degradation characteristic of the antibiotics, the antibiotics are difficult to be completely oxidized and degraded, microorganisms in the sludge can inhibit the antibiotics, and the antibiotics are easy to be prevented from being treated and remain in a terminal water body due to the comprehensive effect of the two factors; the adsorption method based on the physical principle only realizes the transfer of the pollutants, so that the antibiotics are transferred to the surface and the interior of the adsorbent, and the pollutants are not really removed from the water body; advanced oxidation technologies (AOPs) mainly include photocatalytic oxidation, fenton oxidation, ozone oxidation, and the like, and have a high removal rate for antibiotics due to the high reactivity of OH, but the mineralization rate is generally low, and the ecological risk is still high.

The catalytic ozone oxidation technology is a novel high-efficiency water treatment technology developed in recent years, and is an improvement and enhancement of ozone oxidation, namely, the technology which is difficult to use O₃The micro and high-stability organic pollutants in the water which is independently oxidized or degraded are thoroughly oxidized, decomposed and removed, the limitation of a single ozone oxidation technology is overcome, and the ozone oxidation reaction rate is improved. Compared with the homogeneous ozone catalytic oxidation technology, the catalyst in the heterogeneous ozone catalytic oxidation technology exists in a solid state, is easy to separate from a water body, can be repeatedly utilized, and is widely applied to actual sewage treatment.

At present, heterogeneous ozone catalysts are mainly obtained by taking activated carbon, molecular sieves, amorphous alumina or titanium dioxide and the like as carriers and one or more of alkali metals, alkaline earth metals, transition metals or noble metals as catalytic active components through an impregnation method, and the catalysts often have the defects of poor structural stability, easy loss (or shedding) of the catalytic active components, low ozone utilization rate and the like in the actual catalytic reaction process.

Disclosure of Invention

The invention aims to provide magnetic suspension 3D ozone catalytic microspheres, a preparation method and application thereof in catalytic ozone mineralization breedingApplication of antibiotics in sewage. The invention firstly uses CS, PVDF and Fe₃O₄And the like as raw materials, preparing a microsphere carrier by adopting a reverse phase suspension method, and then combining a catalytic active metal component through chemical chelation to obtain the 3D microsphere with the catalytic ozonation function. The microsphere has good suspension stability in natural state and following with O₃Micro bubbles rotate at uniform speed and are beneficial to O₃And antibiotics are adsorbed on the surfaces of the microspheres to increase O₃The utilization rate of the antibiotics is improved, and the mineralization of the antibiotics in the culture sewage is promoted; meanwhile, the magnetic microsphere is simple to prepare, can be repeatedly utilized and has high application value.

In order to achieve the purpose, the invention adopts the following technical scheme:

a magnetically suspended 3D ozone-catalyzing microball is prepared from CS, PVDF and Fe₃O₄And the like as raw materials, preparing a microsphere carrier by adopting an inverse suspension method, and then combining a catalytic active metal component through chemical chelation to obtain the 3D microsphere with the catalytic ozonation function. The preparation method comprises the following specific steps:

(1) weighing a certain amount of CS, dissolving the CS in 2.0 wt% of acetic acid aqueous solution, and preparing 3.0 wt% of chitosan acetic acid aqueous solution, which is marked as light yellow sol A; dissolving 15.0g of PVDF powder in 100ml of LDMAC, adding 5.0g of PVP, mechanically stirring for 1 day at 60 ℃, standing and defoaming to obtain a casting solution B;

(2) respectively weighing 8mM trisodium citrate, 4mM ferric chloride hexahydrate and 12mM urea, dissolving in 80mL deionized water, adding 0.6g polyacrylamide and 0.3g polyethylene glycol, transferring the solution into a reaction kettle for high-temperature reaction, filtering, washing and drying to obtain magnetic Fe₃O₄Nanoparticles;

(3) uniformly mixing the sol A and the casting solution B, and then mixing the sol A and the casting solution B with magnetic Fe₃O₄Compounding nano particles, and carrying out ultrasonic reaction for 30 min; slowly adding into an organic phase consisting of 160mL of liquid paraffin and 8mL of Span-80 under stirring, and fully stirring for 30min at normal temperature to obtain a microsphere carrier; then sequentially adding 10mL of 0.5 wt% glutaraldehyde solution and 30mL of mixed solution containing cerium nitrate, manganese nitrate and cobalt nitrate, continuously stirring, chemically crosslinking for 12h, filtering, and removing deionized water and anhydrousRepeatedly washing with water and ethanol; then placing the mixture into NaOH solution with the pH of 9-10 for curing reaction for 2 hours, taking out the mixture, and repeatedly washing the mixture with deionized water until the mixture is neutral; and finally, drying the microspheres in a vacuum drying oven at 60 ℃ for 8 hours to obtain the microspheres.

Further, the high-temperature reaction in the step (2) is specifically carried out in a vacuum drying oven at 200-300 ℃ for 8-10 h.

Further, the sol A, the casting solution B and Fe in the step (3)₃O₄The mass ratio of the magnetic nanoparticles is (2-8): (4.5-7.5): 1-4).

Further, in the ultrasonic reaction in the step (3), the frequency of ultrasonic waves is 40-60 HZ.

Furthermore, the content ratio of the catalytic active components Ce, Mn and Co in the step (3) is (1-2) wt%: 6-10) wt%: 5-8) wt% based on the weight of the carrier.

Furthermore, the size of the microsphere prepared by the invention is 0.1-0.2 μm, the pore diameter is 10-50 nm, and the specific surface area is 172-214 m²The density of surface acid sites is 0.8-2.7 mmol/g, and the compressive mechanical strength of the spherical particles is more than 3N.

The invention has the following remarkable advantages:

(1) the catalytic active components (Ce, Mn and Co) of the magnetic suspension 3D ozone catalytic microsphere prepared by the invention are fixed by chelating with active amino in CS molecules in a chemical bonding mode, so that the loss or falling of the active components is effectively prevented, and the life cycle of the microsphere (ozone catalyst) is prolonged. The highly dispersed high-density metal sites are active centers, metal ions completely exposed on the surfaces or the channels of the microspheres can provide 100% utilization rate, and the catalytic performance is basically kept stable in the long-term or repeated use process. Further, Fe is embedded₃O₄The suspended 3D microspheres of the magnetic particles can be well recovered through magnetic separation, so that the recycling rate is improved, and the use cost is reduced.

(2) Because the carrier of the ozone catalyst commonly used in the prior art is mainly molecular sieve and gamma-Al₂O₃And carbon materials, and the like, and a wet impregnation method, a hydrothermal method, a coprecipitation method, and the like are generally usedAnd the surface of the carrier is loaded with transition metal and oxide thereof to prepare the catalyst with different catalytic performances. But the preparation process is relatively complex and the preparation conditions are severe, so that the ozone catalytic oxidation is limited to be widely applied. The invention selects cheap and easily available materials to prepare the catalyst carrier, the preparation method is simple, and the prepared microspheres have moderate surface area, larger pore size and smaller internal diffusion resistance, and are beneficial to the smooth operation of catalytic reaction.

(3) In the invention, CS is rich in hydroxyl and amino, and catalytic active components Ce, Mn and Co ions and active amino are crosslinked into a three-dimensional network structure through chelation and are uniformly distributed in the microspheres to form the magnetic suspension 3D ozone catalytic microspheres rich in hydroxyl and Lewis acid sites. The microspheres are in O₃The uniform rotation is driven by the micro bubbles, and the hydroxyl is taken as a hydrophilic group to be beneficial to organic matters and O₃Attached to the surface of the microsphere and benefit O₃Attack organic matter, degrade to produce ozonized product (organic intermediate), and increase O₃Mass transfer and utilization rate; the Ce and Co with Lewis acid sites have excellent electron transfer efficiency, play a role of electron shuttling in the catalytic reaction process and generate synergistic effect with Mn, Fe and Na to activate O₃Rapidly decomposed into OH and/or O₂ ^-Mineralization of organic intermediates adsorbed on the surface of the microspheres to CO₂And H₂O and other inorganic small molecular substances to achieve the effect of high purification.

Drawings

FIG. 1 is a transmission electron micrograph of microspheres of example 1;

FIG. 2 is microspherical catalytic O₃A schematic diagram of a process device for mineralizing antibiotics in aquaculture sewage;

1-ozone generator, 2-ozone concentration analyzer, 3-ozone reaction column, 4-culture sewage, 5-peristaltic pump, 6-sampling port, 7-O₃Micro bubbles, 8-microspheres (ozone catalyst), 9-perforated plates, 10-ozone destructor, 11-liquid storage tank and 12-tail gas;

FIG. 3 shows microspheres/O of example 1₃The circulating mineralization effect on antibiotics in the culture sewage is achieved;

FIG. 4 shows microspheres of example 1 (six cycles)/O₃The treatment effect and the biodegradability of COD and TOC are changed, wherein a beaker a in an illustration is before mineralization and a beaker b in the illustration is after mineralization;

FIG. 5 shows microspheres of example 1 (six cycles)/O₃And (4) the retention rates of TN, TP and TK after the antibiotics in the culture sewage are mineralized.

Detailed Description

For further disclosure, but not limitation, the present invention is further described in detail below with reference to examples.