CN117923635A

CN117923635A - Method for removing antibiotics by mixing goethite and pyrite and application

Info

Publication number: CN117923635A
Application number: CN202410092530.7A
Authority: CN
Inventors: 王志君; 傅卫江; 汪剑锋; 黄榧; 张睿阳; 朱昕阳; 董华平; 吕瑛; 廖庆; 沈洁
Original assignee: Tongchuang Engineering Design Co ltd; University of Shaoxing
Current assignee: Tongchuang Engineering Design Co ltd; University of Shaoxing
Priority date: 2024-01-23
Filing date: 2024-01-23
Publication date: 2024-04-26

Abstract

The invention discloses a method for removing antibiotics by mixing goethite and pyrite and application thereof, comprising the following steps: (1) crushing pyrite and goethite; (2) preparing antibiotic wastewater; (3) Mixing pyrite and goethite with antibiotic wastewater in different proportions for reaction; and applies the method to stormwater treatment. The method mixes goethite and pyrite for degrading antibiotics in water, has wide pH adaptability, mild reaction environment, low cost and high removal efficiency, realizes 'waste treatment with waste', and has important significance on environment.

Description

Method for removing antibiotics by mixing goethite and pyrite and application

Technical Field

The invention relates to the technical field of wastewater treatment, in particular to a method for removing antibiotics by mixing goethite and pyrite and application thereof.

Background

Antibiotics (Antibiotic) are mainly secondary metabolites or synthetic analogues produced by bacteria, moulds or other microorganisms, which inhibit or kill pathogenic micro-organisms, and are now widely used in the treatment of human and animal diseases. Due to the discharge of waste water from pharmaceutical industry, medical antibiotics and excessive use in livestock breeding industry, antibiotics with certain concentration remain in surface water and underground water, and the long-term residual antibiotics can cause serious harm to human health and aquatic ecosystems. The polluted surface water and underground water flow into a lake, and form rainwater after evaporation, wherein antibiotic pollutants remain in the rainwater; even if clean and pollution-free rainwater falls to the ground, the rainwater can be converged with surface water and ground water polluted by antibiotics to form polluted water.

Currently, methods for removing antibiotics include physical, biological and chemical methods. The physical method mainly adopts methods such as adsorption, precipitation, membrane separation technology and the like, but only transfers and concentrates antibiotics from water to a new phase, which is easy to cause secondary pollution to the environment. Biological methods utilize enzyme catalytic systems of microorganisms to reduce nitro groups in antibiotics into amino compounds with lower toxicity, and common methods include an activated sludge method, a contact oxidation method, a membrane reaction method and the like, but the microbial method is only applicable to low-concentration antibiotic solutions. The chemical method is to remove antibiotics by oxidation or reduction, and uses chemical reagent to convert antibiotics into low-toxicity harmless substances through electron loss and electron loss, so that the method has high efficiency and low cost and is widely applied to removal of antibiotic drugs.

Iron-based metal catalysts have been receiving a great deal of attention because of their excellent catalytic performance and environmental friendliness, but a large number of iron-based metal catalysts are prepared by synthesis, and are costly and easily polluting the environment. Goethite (Goethite) is formed by pyrite, magnetite and other iron ores under the weathering condition, and is tailings in the environment; pyrite (Pyrite) is the most abundant iron sulfide on earth and its main component is FeS ₂, usually in the form of cubes, octahedra, etc. Because of the high content of elemental sulfur in pyrite, it is often used as a feedstock for the preparation of sulfur and sulfuric acid. If the two waste minerals pyrite and goethite can be utilized, a composite material with low cost for removing antibiotics in the environment is developed, so that the effect of treating waste with waste is realized, and the method has important significance to the environment.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide a method for removing antibiotics by mixing goethite and pyrite and application thereof, wherein the method comprises the steps of mixing goethite and pyrite to remove the antibiotics in wastewater and applying the mixture to the treatment of the antibiotics in rainwater.

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

A method for removing antibiotics by mixing goethite and pyrite, comprising the steps of:

(1) Crushing pyrite and goethite;

(2) Preparing antibiotic wastewater;

(3) Pyrite and goethite are mixed and reacted with the antibiotic wastewater in different proportions.

The particle size of pyrite in the step (1) is 100-400 meshes, and the particle size of goethite is 100-400 meshes.

The antibiotic wastewater in the step (2) contains metronidazole or chloramphenicol, the pH value of the antibiotic wastewater is 6-10, and the concentration of the metronidazole or chloramphenicol is 5-30ppm.

The antibiotic wastewater in the step (2) is the mixed solution of buffer solutions with different pH values and metronidazole or chloramphenicol, the antibiotic wastewater with the pH value of 6 is the mixed solution of acetic acid-sodium acetate buffer solution and metronidazole or chloramphenicol, the antibiotic wastewater with the pH value of 7 is the mixed solution of MES buffer solution and metronidazole or chloramphenicol, the antibiotic wastewater with the pH values of 8 and 9 is the mixed solution of Tris-HCl buffer solution and metronidazole or chloramphenicol, and the antibiotic wastewater with the pH value of 10 is the mixed solution of glycine buffer solution and metronidazole or chloramphenicol.

In the step (3), the mass ratio of pyrite to goethite is (1/3-3): 1.

Use of a method for removing antibiotics by mixing goethite and pyrite in the treatment of antibiotic contaminated stormwater.

The beneficial effects of the invention are as follows:

1. Pyrite is a sulfur-containing aged iron-based mineral, often distributed as tailings in soil and sediments, with a standard reduction electrode potential of +0.35V, and a degree of reducibility. Goethite is a particle structure with stable chemical properties and large specific surface area, and can be stably existing in acid soil. Pyrite can reduce Fe (III) in goethite into Fe (II), the leaching amount of Fe (II) in the system is increased, and the treatment of waste with waste is realized through oxidizing substances such as metronidazole, chloramphenicol and the like in the Fe (II) reduction system.

2. The system can be used for efficiently removing the metronidazole and the chloramphenicol within the pH range of 6-10, has wider pH adaptability, and can be widely applied to the treatment of antibiotics in rainwater.

3. The method uses natural pyrite and goethite as raw materials, directly adds the raw materials into the antibiotic wastewater for removal without pretreatment, and can react at normal temperature, thus having mild reaction environment, low cost and high removal efficiency.

4. The removal rate of metronidazole and chloramphenicol from goethite and pyrite is very fast at pH 8-10, and the removal rate of antibiotics is high due to the formation of sulfate radical type green rust at pH 8 and 9 and magnetite at pH 10.

5. In the process of cooperatively removing antibiotics from goethite and pyrite, the pH value in the system is reduced, the cooperative removal effect is weak under an acidic condition, and the introduction of the buffer system can maintain the reaction system within a pH range, so that the removal efficiency is improved.

Drawings

FIG. 1 is a graph of example 1 for removal of 10ppm metronidazole over 360 min;

FIG. 2 is a graph of example 2 for removal of 10ppm metronidazole over 360 min;

FIG. 3 is a graph of example 3 removal of 10ppm metronidazole over 360 min;

FIG. 4 is a graph of example 4 removal of 10ppm metronidazole over 360 min;

FIG. 5 is a graph of example 5 removal of 10ppm metronidazole over 360 min;

FIG. 6 is a graph of example 5 removal of 10ppm metronidazole over 10 days;

FIG. 7 is a graph of example 6 removal of 20ppm metronidazole over 360 min;

FIG. 8 is a graph of example 7 removal of 20ppm metronidazole over 360 min;

FIG. 9 is a graph of example 8 removal of 20ppm metronidazole over 360 min;

FIG. 10 is a graph of example 9 removal of 20ppm metronidazole over 360 min;

FIG. 11 is a graph of example 10 for removal of 30ppm metronidazole over 360 min;

FIG. 12 is a graph of example 11 for removal of 30ppm metronidazole over 360 min;

FIG. 13 is a graph of example 12 for removal of 30ppm metronidazole over 360 min;

FIG. 14 is a graph of example 13 removal of 30ppm metronidazole over 360 min;

FIG. 15 is a graph of example 14 at pH 6 for 360min to remove 20ppm chloramphenicol;

FIG. 16 is a graph of example 14 for the removal of 20ppm chloramphenicol at pH 7 for 360 min;

FIG. 17 is a graph of example 14 for the removal of 20ppm chloramphenicol at pH 8 for 360 min;

FIG. 18 is a graph of example 14 for the removal of 20ppm chloramphenicol at pH 9 for 360 min;

FIG. 19 is a graph of example 14 at pH 10 for 360min to remove 20ppm chloramphenicol;

FIG. 20 is a scanning electron micrograph of a mineral from which chloramphenicol has been removed from 0.45g of natural pyrite +0.15g of goethite at pH 9 in example 14;

FIG. 21 is a graph of comparative example 3 with the removal of 20ppm metronidazole at pH 6 over 360 min;

FIG. 22 is a graph of comparative example 3 for removal of 20ppm metronidazole at pH 7 over 360 min;

FIG. 23 is a graph of comparative example 3 with the removal of 20ppm metronidazole at pH 8 over 360 min;

FIG. 24 is a graph of comparative example 3 for removal of 20ppm metronidazole at pH 9 over 360 min.

Detailed Description

The invention is further described with reference to the drawings and detailed description which follow:

Example 1

(1) Taking natural pyrite (purchased from the process plant of Huadong Tang Tang in Guangzhou), crushing and sieving to obtain 100-mesh natural pyrite powder for later use; the goethite is sieved to obtain the goethite with the grain diameter of 100 meshes for standby.

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mL of acetic acid-sodium acetate buffer solution into each reaction bottle, adding 0.01g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain the artificially synthesized metronidazole wastewater with the pH of 6 and the concentration of 10 ppm.

(3) 0.3G of natural pyrite (2 g/L pyrite (Pyrite) is contained in a reaction bottle), 0.15g of natural pyrite+0.15 g of goethite (1 g/L pyrite (Pyrite) +1g/L goethite (Goethite) is contained in a reaction bottle), 0.3g of natural pyrite+0.15 g of goethite (2 g/L pyrite (Pyrite) +1g/L goethite (Goethite) and 0.45g of natural pyrite+0.15 g of goethite (3 g/L pyrite (Pyrite) +1g/L goethite (Goethite) are respectively added into each reaction bottle, and the mixture is reacted for 360 minutes in an oscillator with the rotating speed of 300r/min and the temperature of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 2

(1) Taking natural pyrite, crushing and sieving to obtain 100-mesh natural pyrite powder for later use; the goethite is sieved to obtain the goethite with the grain diameter of 100 meshes for standby.

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mL MES buffer solution (morpholinoethanesulfonic acid buffer solution) into each reaction bottle, adding 0.01g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain the artificially synthesized metronidazole wastewater with the pH of 7 and the concentration of 10 ppm.

(3) 0.3G of natural pyrite (2 g/L Pyrite g in the reaction flask), 0.15g of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/LGoethite in the reaction flask), 0.3g of natural pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the reaction flask) and 0.45g of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/LGoethite in the reaction flask) are added into each reaction flask, and the mixture is reacted for 360 minutes in an oscillator with the rotating speed of 300r/min and the temperature of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 3

(2) Taking 4 reaction bottles with 250mL, adding 150mLTris-HCl buffer solution (tris (hydroxymethyl) aminomethane hydrochloride buffer solution) into each reaction bottle, adding 0.01g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain the artificially synthesized metronidazole wastewater with the pH of 8 and the concentration of 10 ppm.

Example 4

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.01g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 9 to obtain the artificially synthesized metronidazole wastewater with the pH of 9 and the concentration of 10 ppm.

As shown in FIGS. 1-4, for examples 1-4 with the graph removed over 360min, the reaction effect was 3g/L Pyrite +1g/LGo ethite >2g/L Pyrite +1g/LGoethite >1g/L Pyrite +1g/LGoethite >2g/L Pyrite. Under the conditions of pH of 7, 8 and 9, 3g/L Pyrite +1g/LGoethite can degrade 10ppm of metronidazole in 60min, and the reaction speed is high.

Example 5

(2) Taking 6 reaction bottles with the volume of 250mL, adding 150mL of rainwater system into each reaction bottle, adding 0.01g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7.46 to obtain the artificially synthesized metronidazole wastewater with the pH of 7.46 and the concentration of 10 ppm.

(3) Each of the reaction bottles was charged with 0.15g of natural pyrite (1 g/L Pyrite in the reaction bottle), 0.15g of goethite (1 g/LGoethite in the reaction bottle), 0.15g of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/LGoethite in the reaction bottle), 0.3g of natural pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the reaction bottle), 0.45g of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/LGoethite in the reaction bottle), and 0.3g of natural pyrite+0.3 g of goethite (2 g/L Pyri te +2g/LGoethite in the reaction bottle), and reacted in a shaker at a rotation speed of 300r/min and 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

FIG. 5 is a graph of example 5 removal of 10ppm metronidazole over 360 min; FIG. 6 is a graph of 10ppm of metronidazole removed within 10 days for example 5, wherein FIG. a is a graph of 1g/L natural pyrite+1 g/L goethite, 1g/L natural pyrite, 1g/L goethite removed 10ppm of metronidazole within 10 days of reaction, FIG. b is a graph of 2g/L natural pyrite+1 g/L goethite removed 10ppm of metronidazole within 10 days of reaction, FIG. c is a graph of 3g/L natural pyrite+1 g/L goethite removed 10ppm of metronidazole within 10 days of reaction, and FIG. d is a graph of 2g/L natural pyrite+2 g/L goethite removed 10ppm of metronidazole within 10 days of reaction. As can be seen from FIGS. 5 and 6, the reaction effect is 3g/L Pyrite+1g/LGoethite>2g/L Pyrite+2g/LGoethite>2g/L Pyrite+1g/LGoethite>1g/LPyrite+1g/LGoethite>1g/L Pyrite>1g/L Goethite.

Example 6

(2) Taking 6 reaction bottles with the volume of 250mL, adding 150mL of acetic acid-sodium acetate buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain the artificially synthesized metronidazole wastewater with the pH of 6 and the concentration of 20 ppm.

(3) 0.15G of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/L Goethite in the reaction flask), 0.3g of natural pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the reaction flask), 0.45g of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/L Goethite in the reaction flask), 0.15g of natural pyrite+0.3 g of goethite (1 g/L Pyrite +2g/L Goethite in the reaction flask), 0.3g of natural pyrite+0.3 g of goethite (2 g/L Pyrite +2g/LGoethite in the reaction flask), 0.15g of natural pyrite+0.45 g of goethite (1 g/L Pyrite +3g/L Goethite in the reaction flask) are added to each reaction flask, and reacted in a shaker at a rotation speed of 300r/min and 25 ℃ for 360min. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 7

(2) Taking 6 reaction bottles with the volume of 250mL, adding 150mL MES buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain the artificially synthesized metronidazole wastewater with the pH of 7 and the concentration of 20 ppm.

(3) 0.15G of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/L Goethite in the reaction flask), 0.3g of natural pyrite+0.15 g of goethite (2 g/L Py rite +1g/LGoethite in the reaction flask), 0.45g of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/L Goethite in the reaction flask), 0.15g of natural pyrite+0.3 g of goethite (1 g/L Pyrite +2g/L G oethite in the reaction flask), 0.3g of natural pyrite+0.3 g of goethite (2 g/L Pyrite +2g/LGoethite in the reaction flask), 0.15g of natural pyrite+0.45 g of goethite (1 g/L Pyrite +3g/L Goethite in the reaction flask) are added to each reaction flask, and reacted in a shaker at a rotation speed of 300r/min and 25 ℃ for 360min. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 8

(2) Taking 6 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain the artificially synthesized metronidazole wastewater with the pH of 8 and the concentration of 20 ppm.

Example 9

(2) Taking 6 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 9 to obtain the artificially synthesized metronidazole wastewater with the pH of 9 and the concentration of 20 ppm.

The removal efficiency values for examples 6-9 are shown in Table 1. As shown in FIGS. 7-10, for examples 6-9 with the graph removed over 360min, the reaction effect was 2g/L Pyrite +2g/LGoethite >3g/L Pyrite +1g/LGoethite >2g/L Pyrit e +1g/LGoethite. When the pH is 9 and the removal rate is 2g/L Pyrite +2g/LGoethite, the Metronidazole can be degraded to 20ppm within 30min, and the reaction speed is the fastest.

TABLE 1

Example 10

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mL of acetic acid-sodium acetate buffer solution into each reaction bottle, adding 0.03g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain the artificially synthesized metronidazole wastewater with the pH of 6 and the concentration of 30 ppm.

(3) Each of the reaction bottles was charged with 0.3g of natural pyrite (2 g/L Pyrite in the reaction bottle), 0.15g of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/L Goethite in the reaction bottle), 0.3g of natural pyrite+0.15 g of goethite (2 g/LPyrite +1g/LGoethite in the reaction bottle), and 0.15g of natural pyrite+0.3 g of goethite (1 g/LPyrite +2g/L Goethite in the reaction bottle), and reacted for 360 minutes in an oscillator at a rotation speed of 300r/min and a rotation speed of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 11

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mL MES buffer solution into each reaction bottle, adding 0.03g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain the artificially synthesized metronidazole wastewater with the pH of 7 and the concentration of 30 ppm.

(3) Each of the reaction bottles was charged with 0.3g of natural pyrite (2 g/L Pyrite in the reaction bottle), 0.15g of natural pyrite+0.15 g of goethite (1 g/L Pyrite +1g/L Goethite in the reaction bottle), 0.3g of natural pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the reaction bottle), and 0.15g of natural pyrite+0.3 g of goethite (1 g/L Pyrite +2g/L Goethite in the reaction bottle), and reacted for 360 minutes in an oscillator at a rotation speed of 300r/min and a rotation speed of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

Example 12

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.03g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain the artificially synthesized metronidazole wastewater with the pH of 8 and the concentration of 30 ppm.

Example 13

(2) Taking 4 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.03g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 9 to obtain the artificially synthesized metronidazole wastewater with the pH of 9 and the concentration of 30 ppm.

As shown in fig. 11-14, for the graphs of examples 10-13 for removal of 30ppm of metronidazole at an initial concentration in 360min, the synergistic removal of goethite and pyrite was superior to the removal of pyrite alone.

Example 14

(2) Artificially synthesized chloramphenicol wastewater with pH of 6, 7, 8, 9, 10 and concentration of 20ppm was prepared respectively. The specific preparation method comprises the following steps: taking 4 reaction bottles with the volume of 250mL, adding 150mL of acetic acid-sodium acetate buffer solution into each reaction bottle, adding 0.02g of chloramphenicol powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain artificially synthesized chloramphenicol wastewater with the pH of 6 and the concentration of 10 ppm; taking 4 reaction bottles with the volume of 250mL, adding 150mLMES buffer solution into each reaction bottle, adding 0.02g of chloramphenicol powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain artificially synthesized chloramphenicol wastewater with the pH of 7 and the concentration of 20 ppm; taking 4 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.02g of chloramphenicol powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain artificially synthesized chloramphenicol wastewater with the pH of 8 and the concentration of 20 ppm; taking 4 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.02g of chloramphenicol powder, shaking uniformly, and regulating the pH of the mixed solution to 9 to obtain artificially synthesized chloramphenicol wastewater with the pH of 9 and the concentration of 20 ppm; taking 4 reaction bottles with the volume of 250mL, adding 150mL glycine buffer solution into each reaction bottle, adding 0.02g chloramphenicol powder, shaking uniformly, and regulating the pH of the mixed solution to 10 to obtain artificially synthesized chloramphenicol wastewater with the pH of 10 and the concentration of 20 ppm.

(3) 0.45G of natural pyrite (3 g/L Pyrite g in a reaction bottle), 0.45g of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/L Goet hite in a reaction bottle), 0.3g of natural pyrite+0.3 g of goethite (2 g/L Pyrite +2g/LGoethite in a reaction bottle) and 0.15g of natural pyrite+0.45 g of goethite (1 g/L Pyrite +3g/L Goethite in a reaction bottle) are respectively added into reaction bottles under different pH conditions, and the mixture is reacted for 360 minutes in an oscillator with the rotating speed of 300r/min and the temperature of 25 ℃. After the completion of the reaction, the concentration of residual chloramphenicol was measured by high performance liquid chromatography.

FIG. 15 is a graph showing the removal of 20ppm chloramphenicol in 360min at pH 6 for example 14, wherein FIG. a is a graph showing the removal of 20ppm chloramphenicol in 360min for 3g/L natural pyrite, 3g/L natural pyrite+1 g/L goethite, 2g/L natural pyrite+2 g/L goethite, and 20ppm chloramphenicol in 360min for 1g/L natural pyrite+3 g/L goethite, and FIG. c is a graph showing the removal of 20ppm chloramphenicol in 360min for reaction; FIG. 16 is a graph showing the removal of 20ppm chloramphenicol at pH 7 for 360min in example 14; FIG. 17 is a graph of example 14 for the removal of 20ppm chloramphenicol at pH 8 for 360 min;

FIG. 18 is a graph showing the removal of 20ppm chloramphenicol in 360min at pH 9 for example 14, wherein FIG. a is a graph showing the removal of 20ppm chloramphenicol in 360min for 1g/L natural pyrite+3 g/L goethite, FIG. b is a graph showing the removal of 20ppm chloramphenicol in 360min for 3g/L natural pyrite+1 g/L goethite, FIG. c is a graph showing the removal of 20ppm chloramphenicol in 360min for 3g/L natural pyrite+1 g/L goethite, and FIG. d is a graph showing the removal of 20ppm chloramphenicol in 360min for 2g/L natural pyrite+2 g/L goethite; FIG. 19 is a graph showing the removal of 20ppm chloramphenicol at pH 10 for 360min in example 14, wherein FIG. a is a graph showing the removal of 20ppm chloramphenicol from 1g/L natural pyrite+3 g/L goethite for 360min, FIG. b is a graph showing the removal of 20ppm chloramphenicol from 3g/L natural pyrite for 360min, FIG. c is a graph showing the removal of 20ppm chloramphenicol from 3g/L natural pyrite+1 g/L goethite for 360min, and FIG. d is a graph showing the removal of 20ppm chloramphenicol from 2g/L natural pyrite+2 g/L goethite for 360 min.

At pH 10, the removal efficiency of the combined removal of chloramphenicol by pyrite alone and pyrite and goethite was 99% within 10min of the reaction. Among them, the pH of 10 is the best, and the pH of 9, 8 and 7 is the worst at pH 6.

As shown in FIG. 20, which is a scanning electron microscope image of a mineral from which chloramphenicol was removed from 0.45g of natural pyrite+0.15 g of goethite at pH 9, it was found that a large amount of rust was formed on the surface of the mineral, and that the formation of the active material was responsible for removal of substances such as metronidazole and chloramphenicol in the system.

At pH 6 and 7, pyrite activates reduction of Fe (III) in goethite to Fe (II) (equation (1)), the leaching amount of Fe (II) in the system increases, and substances having oxidizing property such as metronidazole, chloramphenicol and the like in the system are reduced by Fe (II).

α-FeOOH+e^-+3H⁺→Fe²⁺+2H₂O (1)

Pyrite reacts with goethite in alkaline conditions at pH 8 and 9 to form sulfate-type patina (Fe (II) ₄Fe(III)₂(OH)₁₂SO₄) (equation (2)) by oxidizing substances such as metronidazole, chloramphenicol, etc. in sulfate-type patina reduction systems. In addition, the reaction is a process of consuming OH ^-, the pH in the system can be reduced, and the removal efficiency is influenced.

2Fe(III)OOH+4Fe(II)+6OH^-+2H₂O+SO₄ ^2-→Fe(II)₄Fe(III)₂(OH)₁₂SO₄ (2)

Pyrite reacts with goethite in alkaline conditions at pH 10 with sulfate to form magnetite (Fe (II) Fe (III) ₂O₄) (equation (3)), substances having oxidizing property such as metronidazole, chloramphenicol, etc. in a system reduced by magnetite. In addition, the reaction is a process of consuming OH ^-, the pH in the system can be reduced, and the removal efficiency is influenced.

2Fe(III)OOH+Fe(II)+2OH^-→Fe(II)Fe(III)₂O₄+2H₂O (3)

Comparative example 1

(1) Taking natural pyrite, crushing and sieving to obtain 100-mesh natural pyrite powder for later use;

(2) Artificially synthesized metronidazole wastewater with the concentration of 20ppm and pH of 6, 7, 8 and 9 is prepared respectively. The specific preparation method comprises the following steps: taking a 250mL reaction bottle, adding 150mL acetic acid-sodium acetate buffer solution into the reaction bottle, adding 0.02g metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain artificially synthesized metronidazole wastewater with the pH of 6 and the concentration of 20 ppm; taking a 250mL reaction bottle, adding 150mLMES buffer solution into the reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain artificially synthesized metronidazole wastewater with the pH of 7 and the concentration of 20 ppm; taking a 250mL reaction bottle, adding 150mLTris-HCl buffer solution into the reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain artificially synthesized metronidazole wastewater with the pH of 8 and the concentration of 20 ppm; taking a 250mL reaction bottle, adding 150mLTris-HCl buffer solution into the reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 9 to obtain the artificially synthesized metronidazole wastewater with the pH of 9 and the concentration of 20 ppm.

(3) 0.3G of natural pyrite (2 g/L Pyrite g in each reaction flask) was added to each reaction flask, and reacted for 360min in an oscillator with a rotation speed of 300r/min and a temperature of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

TABLE 2

As shown in table 2, the removal efficiency values of Pyrite alone at pH 6-9. Experimental results indicate that the effect of pyrite alone in removing metronidazole is inferior to the synergistic removal of pyrite and goethite.

Comparative example 2

(1) Sieving goethite to obtain goethite powder with the particle size of 100 meshes for later use;

(2) Artificially synthesized metronidazole wastewater with the concentration of 10ppm and pH of 6, 7, 8 and 9 is prepared respectively. The specific preparation method comprises the following steps: 150mL of acetic acid-sodium acetate buffer solution is added into a 250mL reaction bottle, 0.01g of metronidazole powder is added, the mixture is uniformly shaken, the pH value of the mixture is regulated to 6, and the artificially synthesized metronidazole wastewater with the pH value of 6 and the concentration of 10ppm is obtained; 150mLMES of buffer solution is added into a 250mL reaction bottle, 0.01g of metronidazole powder is added, the mixture is uniformly shaken, the pH value of the mixture is regulated to 7, and the artificially synthesized metronidazole wastewater with the pH value of 7 and the concentration of 10ppm is obtained; 150mLTris-HCl buffer solution is added into a 250mL reaction bottle, 0.01g of metronidazole powder is added, the mixture is uniformly shaken, the pH value of the mixture is adjusted to 8, and the artificially synthesized metronidazole wastewater with the pH value of 8 and the concentration of 10ppm is obtained; 150mLTris-HCl buffer solution is added into a 250mL reaction bottle, 0.01g of metronidazole powder is added, the mixture is uniformly shaken, the pH value of the mixture is adjusted to 9, and the artificially synthesized metronidazole wastewater with the pH value of 9 and the concentration of 10ppm is obtained; 150mL glycine buffer solution and 0.01g metronidazole powder are added into a 250mL reaction bottle, the mixture is uniformly shaken, the pH value of the mixture is regulated to 10, and the artificially synthesized metronidazole wastewater with the pH value of 10 and the concentration of 10ppm is obtained; .

(3) 0.3G goethite (2 g/L Goethite g) is added into each reaction flask, and the mixture is reacted for 360min in an oscillator with the rotating speed of 300r/min and the temperature of 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

After the reaction is finished under the condition of pH value of 6-10, a large amount of metronidazole remains in the system, and the removal rate of goethite is 0-2% similar to the initial concentration, so that the independent goethite has no substantial removal effect on the metronidazole.

Comparative example 3

(1) Taking artificially synthesized pyrite (FeS 2, purchased from Shanghai Ala Biochemical technology Co., ltd.), pulverizing, sieving to obtain 100 mesh artificially synthesized pyrite powder for later use; the goethite is sieved to obtain the goethite with the grain diameter of 100 meshes for standby.

(2) And respectively preparing artificially synthesized metronidazole wastewater with pH of 6, 7, 8 and 9 and concentration of 20 ppm. The specific preparation method comprises the following steps: taking 7 reaction bottles with the volume of 250mL, adding 150mL of acetic acid-sodium acetate buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 6 to obtain artificially synthesized metronidazole wastewater with the pH of 6 and the concentration of 10 ppm; taking 7 reaction bottles with the volume of 250mL, adding 150mL MES buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 7 to obtain artificially synthesized metronidazole wastewater with the pH of 7 and the concentration of 20 ppm; taking 7 reaction bottles with the volume of 250mL, adding 150mLTris-HCl buffer solution into each reaction bottle, adding 0.02g of metronidazole powder, shaking uniformly, and regulating the pH of the mixed solution to 8 to obtain artificially synthesized metronidazole wastewater with the pH of 8 and the concentration of 20 ppm; 7 reaction bottles of 250mL are taken, 150mLTris-HCl buffer solution is added into each reaction bottle, 0.02g of metronidazole powder is added, the mixture is uniformly shaken, the pH of the mixture is regulated to 9, and the artificially synthesized metronidazole wastewater with the pH of 9 and the concentration of 20ppm is obtained.

(3) 0.45G of synthetic pyrite (3 g/L Pyrite in the reaction flask), 0.15g of synthetic pyrite+0.15 g of goethite (1 g/L Pyrite +1g/L Goethite in the reaction flask), 0.3g of synthetic pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the reaction flask), 0.45g of synthetic pyrite+0.15 g of goethite (3 g/L Pyrite +1g/L Goethite in the reaction flask), 0.15g of synthetic pyrite+0.3 g of goethite (1 g/L Pyrite +2g/L Goethite in the reaction flask), 0.3g of synthetic pyrite+0.3 g of goethite (2 g/L Pyrite +2g/LGoethite in the reaction flask), 0.15g of synthetic pyrite+0.45 g of goethite (563 g/L Pyrite +1 g/3298 in the reaction flask) are respectively added to the reaction flask under different pH conditions, and the shaking reactor is operated at a rotation speed of 360min of 300. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

21-24 Show the removal graph of comparative example 3, 21 shows the graph of comparative example 3 for removing 20ppm of metronidazole in 360min at pH 6, wherein FIG. a shows the graph of 1g/L of synthetic pyrite+3 g/L of goethite for removing 20ppm of metronidazole in 360min, FIG. b shows the graph of 3g/L of synthetic pyrite for removing 20ppm of metronidazole in 360min, FIG. c shows the graph of 1g/L of synthetic pyrite+1 g/L of goethite for removing 20ppm of metronidazole in 360min, FIG. d shows the graph of 2g/L of synthetic pyrite+1 g/L of goethite for removing 20ppm of metronidazole in 360min, FIG. e shows the graph of 1g/L of synthetic pyrite+2 g/L of goethite for removing 20ppm of metronidazole in 360min, FIG. f shows the graph of 3g/L of synthetic pyrite+1 g/L of synthetic pyrite for removing 20ppm of metronidazole in 360min, and FIG. 2g/L of synthetic pyrite+2 g/L of goethite for removing 20ppm of metronidazole in 360 min; FIG. 22 is a graph of comparative example 3 for removal of 20ppm metronidazole at pH 7 over 360 min; FIG. 23 is a graph of comparative example 3 with the removal of 20ppm metronidazole at pH 8 over 360 min; FIG. 24 is a graph of comparative example 3 in which 20ppm of metronidazole was removed in 360min at pH 9, wherein FIG. a is a graph of 3g/L of synthetic pyrite, 2g/L of synthetic pyrite+1 g/L of goethite, 3g/L of synthetic pyrite+1 g/L of goethite, 2g/L of synthetic pyrite+2 g/L of goethite in 360min of reaction, FIG. b is a graph of 1g/L of synthetic pyrite+3 g/L of goethite in 360min of reaction, 20ppm of metronidazole was removed in 360min of reaction, FIG. c is a graph of 1g/L of synthetic pyrite+2 g/L of goethite in 360min of reaction, and FIG. d is a graph of 1g/L of synthetic pyrite+1 g/L of goethite in 360min of reaction, 20ppm of metronidazole.

Comparative example 3 the efficiency of removing metronidazole using artificial synthetic pyrite was lower than that of natural pyrite.

Comparative example 4

(2) Taking 2 reaction bottles with 250mL, adding 0.01g of metronidazole powder into each reaction bottle, shaking uniformly, and regulating the pH of the metronidazole solution to 9 by using 0.1M NaOH to obtain metronidazole wastewater with the initial pH of 9 and the concentration of 10 ppm; 2 reaction bottles of 250mL are taken, 0.01g of metronidazole powder is added into each reaction bottle, the mixture is shaken uniformly, and the pH of the metronidazole solution is regulated to 7 by 0.1M NaOH, so that the metronidazole wastewater with the initial pH of 7 and the concentration of 10ppm is obtained.

(3) Each of the reaction flasks was charged with 0.3g of natural pyrite (2 g/L Pyrite in the flask) and 0.3g of natural pyrite+0.15 g of goethite (2 g/L Pyrite +1g/LGoethite in the flask), and reacted for 360 minutes in a shaker at 25 ℃. After the reaction, the concentration of residual metronidazole was determined by high performance liquid chromatography.

After the reaction, under the condition that the initial pH is 7, the removal efficiency of 0.3g of natural pyrite is 3.1%, the pH value of the solution after the reaction is 3.51, the removal efficiency of 0.3g of natural pyrite plus 0.15g of goethite is 5.4%, and the pH value of the solution after the reaction is 3.57; the initial pH was 9, the removal efficiency of 0.3g of natural pyrite was 7.1%, the pH of the solution after the completion of the reaction was 5.45, the removal efficiency of 0.3g of natural pyrite+0.15 g of goethite was 24.5%, and the pH of the solution after the completion of the reaction was 5.70.

Example 15

(2) Taking 3 reaction bottles of 250mL, adding 150mL of rainwater (a collecting tank is arranged on the ground, after raining on the day, rainwater flows through the ground, groundwater and surface water to be converged into the collecting tank together, and water in the collecting tank is used as rainwater in the experiment).

(3) 0.45G of natural pyrite+0.15 g of goethite (3 g/L Pyrite +1g/L Goethite in the reaction flask), 0.3g of natural pyrite+0.3 g of goethite (2 g/L Pyrit e +2g/LGoethite in the reaction flask) and 0.15g of natural pyrite+0.45 g of goethite (2 g/L Pyrite +2g/L Goethite in the reaction flask) are respectively added into the reaction flask, and reacted for 360 minutes in an oscillator with the rotating speed of 200r/min and the temperature of 25 ℃. After the reaction, the concentrations of residual metronidazole and chloramphenicol were determined by high performance liquid chromatography.

Before the reaction, the concentration of the metronidazole in the rainwater is measured to be 10ppm, the concentration of the chloramphenicol is measured to be 5ppm, and after the reaction is carried out for 360min, the reaction systems of 3g/L Pyrite +1g/L Goethite, 2g/L Pyrite +2g/LGoethite and 2g/L Pyrite +2g/LGoethite have no residual metronidazole and chloramphenicol.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. A method for removing antibiotics by mixing goethite and pyrite, comprising the steps of:

(1) Crushing pyrite and goethite;

(2) Preparing antibiotic wastewater;

2. The method for removing antibiotics by mixing goethite and pyrite according to claim 1, wherein the particle size of pyrite in the step (1) is 100-400 mesh, and the particle size of goethite is 100-400 mesh.

3. The method for removing antibiotics by mixing goethite and pyrite according to claim 1, wherein the antibiotic wastewater in the step (2) contains metronidazole or chloramphenicol, the pH value of the antibiotic wastewater is 6-10, and the concentration of the metronidazole or chloramphenicol is 5-30ppm.

4. The method for removing antibiotics by mixing goethite and pyrite according to claim 1, wherein the antibiotic wastewater in the step (2) is a mixed solution of buffer solutions with different pH values and metronidazole or chloramphenicol, the antibiotic wastewater with the pH value of 6 is a mixed solution of acetic acid-sodium acetate buffer solution and metronidazole or chloramphenicol, the antibiotic wastewater with the pH value of 7 is a mixed solution of MES buffer solution and metronidazole or chloramphenicol, the antibiotic wastewater with the pH values of 8 and 9 is a mixed solution of Tris-HCl buffer solution and metronidazole or chloramphenicol, and the antibiotic wastewater with the pH value of 10 is a mixed solution of glycine buffer solution and metronidazole or chloramphenicol.

5. A method for removing antibiotics by mixing goethite and pyrite according to claim 1, wherein the mass ratio of pyrite to goethite in the step (3) is (1/3-3): 1.

6. Use of a method according to any one of claims 1-5 for removing antibiotics by mixing goethite and pyrite in the treatment of antibiotic contaminated stormwater.