A catalytic oxidation integrated material for treating high-salt antibiotic wastewater

Abstract

The present invention provides a catalytic oxidation integrated material for treating high-salt antibiotic wastewater, which includes a carbon material and a persulfate, wherein the mass ratio of the carbon material to the persulfate is 1:1 to 1:10, and the two are mechanically ball-milled and activated to form a composite. The present invention pioneers the mechanical activation of the carbon material catalyst and the solid persulfate (PS) oxidant, and produces an activation effect between the solid and solid through physical and mechanical mixing during the ball milling process, without adding the prepared activated carbon catalytic material to the oxidant PS solution to produce oxidizing species; a convenient, high-yield and high-efficiency advanced oxidation treatment process for difficult-to-degrade organic pollutants can be obtained. The catalytic oxidation integrated material prepared by the present invention has a high-efficiency treatment effect on antibiotic wastewater, can still maintain degradation performance in a high-salt environment, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of material synthesis, and in particular relates to a catalytic oxidation integrated material for treating high-salt antibiotic wastewater. Background Art

[0002] Highly water-soluble and poorly biodegradable antibiotics have become a widespread emerging organic pollutant in aquatic environments, and their extensive use poses a serious threat to public health and the natural environment. Tetracyclines, a broad-spectrum synthetic antibiotic, are widely used in aquaculture, animal husbandry, agricultural production, and the medical industry due to their low cost and effective bactericidal properties. As one of the most widely used antibiotics in various countries, tetracycline (TC) poses a serious threat to human health and the environment due to its excessive use and incomplete degradation. Due to its antibacterial properties and stable chemical structure, it is difficult to treat using traditional methods such as biodegradation. Therefore, the development of low-cost, efficient TC treatment technologies is extremely urgent.

[0003] Advanced oxidation processes (AOPs) can effectively remove these refractory organic pollutants. Among them, persulfate (PS)-based AOPs can produce highly active sulfate radicals (SO4· - ), has a higher redox potential and a longer half-life (2.5-3.1V, 30-40μs) than the hydroxyl radical (·OH) (1.8-2.7V, <1μs), and its advantages such as easy storage and transportation make it have great development potential in the treatment of wastewater containing antibiotics. In addition to high-energy activation methods such as heat, UV radiation, and ultrasound / microwave, the currently widely used transition metals (such as Fe, Cu, Co, Ni, Mn, etc.) and metal oxides can efficiently activate PS to form SO4· - However, metal ions tend to precipitate at high pH (e.g., Fe 3+ The formation of iron hydroxide precipitates) can only effectively activate PS under acidic conditions. In addition, the large amount of metal-containing sludge produced after the reaction will lead to additional treatment costs. Therefore, a new material is urgently needed for the treatment of antibiotic wastewater. Summary of the Invention

[0004] In view of this, the present invention aims to propose a catalytic oxidation integrated material for treating high-salt antibiotic wastewater, so as to overcome the shortcomings of the existing technology and be used for the treatment of high-salt difficult-to-degrade antibiotic wastewater; the present invention can produce an activation effect between solids through physical and mechanical mixing during the ball milling process, and the pressure and temperature in the closed ball milling tank will gradually increase during the ball milling process, causing the surface lattice to change, forming a solid solution or undergoing synthesis or decomposition reactions, and mechanically activate the carbon material and the solid persulfate oxidant together, and obtain the catalytic oxidation integrated material through one-step mechanical treatment.

[0005] Carbon materials as SO4-based - Carbon materials can activate PS oxidants to generate HO, SO4 - 、O2 - and 1O2 and other free radicals and active oxygen, thereby effectively degrading a variety of organic pollutants in the aqueous phase.

[0006] In the prior art, solid carbon materials are typically added to a PS solution, where they react at the solid-liquid interface to produce oxidizing species such as sulfate and hydroxyl radicals. This method directly uses solid PS and carbon together through ball milling to form a solid composite. When added to an aqueous solution, a solid-solid reaction occurs, resulting in minimal PS dissolution.

[0007] The present invention uses carbon material as a catalyst and PS as an oxidant, and directly mechanically ball-mills the solid catalyst and oxidant together for activation and compounding to obtain a catalytic oxidation integrated material. This not only solves the problems of high cost and low yield in preparing carbon catalytic materials through chemical activation, but also simplifies the process of separately adding solid catalysts and liquid oxidants in the traditional AOPs reaction process.

[0008] Compared with the existing technology, the catalytic oxidation integrated material for treating high-salt antibiotic wastewater of the present invention has the following advantages:

[0009] 1) The present invention uses carbon material as a catalyst and PS as an oxidant, and directly activates the solid catalyst and the oxidant through mechanical action and simultaneously compounds them, thereby obtaining a catalytic oxidation integrated material in a green, economical, simple and efficient way.

[0010] 2) The mechanochemical process not only activates the carbon material to produce a non-metallic AOPs catalyst, generating surface functional groups and defects that serve as catalytic sites, but also induces lattice deformation in the PS, promoting electron transfer and oxidant activation, leading to the degradation of pollutants through both free radical and non-free radical mechanisms. This composite material possesses simultaneous adsorption, catalysis, and oxidation capabilities, making it a highly effective and user-friendly advanced oxidation treatment material.

[0011] 3) The present invention efficiently utilizes carbon materials and oxidants to obtain high-performance composite catalytic oxidation materials through a simple and low-consumption one-step mechanical synthesis method. It not only solves the problems of easy dissolution and narrow applicable pH range of traditional metal AOPs catalysts, but also improves the activation efficiency of the oxidant. It can quickly and efficiently degrade emerging organic pollutants such as antibiotics, and can maintain excellent treatment performance even in high-salt wastewater. It has broad application prospects in wastewater treatment in the chemical, pharmaceutical and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1The following are XRD patterns of different catalytic oxidation materials used in the examples. (AC@PS)-M is the integrated catalytic oxidation material obtained in Example 2; AC-M is the ball-milled carbon material; PS-M is the ball-milled persulfate; and PS is the unmilled persulfate.

[0013] Figure 2 1 is a comparison chart of TC removal by different catalytic oxidation materials in the examples.

[0014] Figure 3 1 is the degradation performance of TC by the catalytic oxidation integrated material under different pH conditions in the examples.

[0015] Figure 4 1 is the degradation performance of TC by the catalytic oxidation integrated material in a high salt environment in the embodiment. DETAILED DESCRIPTION

[0016] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.

[0017] The present invention will be described in detail below with reference to the embodiments.

[0018] A method for preparing a catalytic oxidation integrated material for treating high-salt antibiotic wastewater comprises the following steps:

[0019] 10g of potassium peroxydisulfate was weighed, added to a certain mass ratio of activated carbon (AC), and placed in a zirconia ball mill. The milling media consisted of 120g of zirconia balls with diameters of 3, 5, and 15mm, with a mass ratio of 3:5:2. The mixture was then purged with nitrogen for 15 minutes, and the mill was operated at 300rpm. The composite material was milled for 12 hours, with the rotation direction changed every 3 hours and a 5-minute rest period. After the milling, the resulting composite material was collected and stored in a dry, oxygen-free glass bottle until ready for use.

[0020] Example 1:

[0021] The mass ratio of carbon material to PS added to the ball mill was 1:1. After nitrogen was purged into the mixed material for 15 min, the ball mill was operated at a speed of 300 rpm and milled for 12 h.

[0022] Example 2:

[0023] The mass ratio of carbon material to PS added to the ball mill was 1:2.5. After nitrogen was purged into the mixed material for 15 min, the ball mill was operated at a speed of 300 rpm and milled for 12 h.

[0024] The XRD pattern of the obtained catalytic oxidation integrated material is as follows: Figure 1 shown.

[0025] Example 3:

[0026] The mass ratio of carbon material to PS added to the ball mill was 1:5. After nitrogen was purged into the mixed material for 15 min, the ball mill was operated at a speed of 300 rpm and milled for 12 h.

[0027] Example 4:

[0028] The mass ratio of carbon material to PS added to the ball mill was 1:8. After nitrogen was purged into the mixed material for 15 min, the ball mill was operated at a speed of 300 rpm and milled for 12 h.

[0029] Example 5:

[0030] The mass ratio of carbon material to PS added to the ball mill was 1:10. After nitrogen was purged into the mixed material for 15 min, the ball mill was operated at a speed of 300 rpm and milled for 12 h.

[0031] Comparative Example:

[0032] The carbon material (activated carbon AC) was not mixed with PS and was ball-milled separately. After nitrogen was purged for 15 min, the carbon material and PS were ball-milled at 300 rpm for 12 h. The carbon material and PS were then mixed at a mass ratio of 1:2.5.

[0033] from Figure 1 The XRD patterns in the figure show that PS has changed after ball milling. Peaks corresponding to the main crystal planes of K2S2O8 appear in the PS spectrum, such as the peak at 27.576° belonging to the (020) crystal plane. The ball-milled PS-M has more characteristic peaks of K2S2O8, such as the peak at 35.193° corresponding to the (012) crystal plane. In addition to the characteristic peaks of K2S2O8, the composite material AC@PS-M after co-ball milling also has a sharp peak corresponding to the (002) crystal plane of carbon, indicating a significant increase in the degree of crystallization of the carbon. This shows that both the carbon material and PS are activated under mechanical action, possessing higher crystallinity and more exposed crystal planes, and are successfully combined to form a composite material.

[0034] The removal performance of the prepared catalytic oxidation integrated material for TC is as follows:

[0035] Antibiotic TC oxidative degradation experiment: 100 ml of tetracycline hydrochloride solution with a concentration of 20 mg / L was prepared with deionized water, 35 mg of the prepared material was added, the reaction bottle was sealed (no deoxygenation was required) and placed in a constant temperature oscillator to react at room temperature (about 25°C) and a speed of 250 r / min. Samples were taken at certain time intervals, with each sampling volume of 0.5 ml. After the sample was filtered through a 0.22 μm filter membrane, the TC concentration was detected by liquid chromatography.

[0036] The experimental results of using different types of catalytic / oxidative materials to treat TC are shown in the attached Figure 2 The amount of carbon material used in the reaction was 10 mg, the amount of PS was 25 mg, and the catalytic / oxidizing material used was prepared in Example 2.

[0037] Unmilled PS had almost no degradation effect on TC, while the mechanical action of ball milling directly activated PS. The degradation efficiency of ball-milled PS increased to 36% after 40 minutes of reaction.

[0038] The adsorption capacity of ball-milled carbon material is 26%, the degradation efficiency of un-ball-milled PS catalyzed by ball-milled carbon material is 39%, and the degradation efficiency of ball-milled PS catalyzed by ball-milled carbon material is 53%.

[0039] The composite material obtained by ball-milling carbon material and PS can almost completely remove TC after 40 minutes of reaction.

[0040] The above experimental results show that simple ball milling treatment can not only improve the oxidation of PS, but also enhance the activation of carbon materials. The carbon material obtained by mechanically ball milling the two materials has a significantly stronger activation effect on PS and can efficiently degrade the antibiotic TC.

[0041] The TC treatment effects of the catalytic / oxidative materials prepared in Examples 1-5 at 40 min of reaction were 98%, 98%, 84%, 48% and 47%, respectively.

[0042] The experiment investigated the effects of pH and anions on the degradation of TC by the catalytic oxidation integrated material obtained by ball milling. It was found that the pH change had little effect on the TC degradation efficiency (see Appendix Figure 3 Using the material prepared in Example 2, TC: 20 mg / L, rotation speed: 220 r / min, T: 25°C, AC: 100 mg / L), the TC degradation rate did not change significantly in the pH range of 3 to 7, and was between 96 and 98%. In the strongly alkaline pH 11 environment, the TC degradation rate could still reach nearly 80%.

[0043] Common anions in water SO4 2- 、Cl - and HCO3 - The degradation of TC in the presence of Figure 4 As shown, (using the material prepared in Example 2, TC: 20 mg / L, pH 4, speed: 220 r / min, T: 25 ° C, AC: 100 mg / L), the content of each ion is 100 mM, that is, SO4 2- 、Cl - and HCO3 - The mass concentrations of TC were 9600 mg / L, 3550 mg / L and 6100 mg / L respectively. In the presence of these three anions, the 40-min degradation rates of TC were 92%, 91% and 88% respectively. PS also produces SO4 during the reaction. 2- ;Cl - During the reaction, it reacts with OH to produce ClOH with oxidizing properties. - 、Cl2· - Free radicals such as HCO3 - Hydrolysis occurs, raising the pH of the reaction system and reducing the survival rate of free radicals, which in turn reduces the degradation rate of TC. Overall, however, the mechanically prepared catalytic oxidation integrated material maintains high degradation performance in high-salinity antibiotic wastewater.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a catalytic oxidation integrated material for treating high-salt antibiotic wastewater, characterized in that: The catalytic oxidation integrated material includes a carbon material and a persulfate, the mass ratio of the carbon material to the persulfate being 1:1 to 1:10, and the two are mechanically ball-milled and activated to form a composite; the carbon material is one or more of activated carbon, graphite, and biochar, and the persulfate is potassium peroxydisulfate (K2S2O8); The preparation of the catalytic oxidation integrated material includes the following steps: 1) Mix the carbon material and persulfate evenly and place them in a ball mill; 2) adding a ball milling medium to the mixed material obtained in step 1), wherein the ball milling medium is zirconia balls, and the diameter of the zirconia balls is 1 to 20 mm; the mass ratio of the added carbon material to the zirconia balls is 1:10-1:200; the diameters of the zirconia balls are divided into three types, namely 3, 5 and 15 mm, and the mass ratio of the zirconia balls of each diameter is (2 to 6):(3 to 8):(1 to 5); 3) After purging the mixture obtained in step 2) with nitrogen for 5 to 20 minutes, the ball mill is operated at a speed of 100 to 500 rpm to grind the mixed material for 8 to 20 hours, changing the rotation direction once every 1 to 5 hours, and stopping the grinding for 2 to 10 minutes in the middle.

2. The method for preparing the catalytic oxidation integrated material for treating high-salt antibiotic wastewater according to claim 1, characterized in that: In step 2), the mass ratio of the added carbon material to the zirconium oxide balls is 1:10-120.

3. Use of the catalytic oxidation integrated material prepared by the preparation method according to claim 1 or 2 in the treatment of antibiotic-contaminated water.

4. The use according to claim 3, characterized in that The antibiotic is tetracycline hydrochloride.

5. The use according to claim 3, characterized in that In sewage, the concentration range of antibiotics is 10-50 mg / L; the anion concentration of high-salt wastewater is 50-200 mM, and the pH is 3-11.

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