Method for removing antibiotics from highly concentrated acidic waste water

Abstract

The application discloses a method for removing antibiotics in high-concentration acidic wastewater, and relates to the technical field of water treatment and resource utilization. The method comprises the following steps: firstly, constructing an organic acid and oxidant molecular coupling system; utilizing the organic acid in the coupling system to couple and stabilize the oxidant molecules, and changing the oxidation selectivity of the oxidant molecules; and coupling the organic acid in the coupling system with the oxidant molecules to realize specific combination with the antibiotic pharmacodynamic functional groups, so as to generate singlet oxygen and super oxygen, selectively remove the antibiotics in the high-concentration acidic wastewater, and realize nearly 100% selectivity and removal rate. Moreover, the organic acid can be recycled and reused, and the residual organic intermediates can be used as carbon sources for subsequent biological treatment.

Description

Technical Field

[0001] This invention belongs to the field of water treatment and resource utilization technology, and specifically relates to a method for removing antibiotics from high-concentration acidic wastewater. Background Technology

[0002] As a major producer and consumer of antibiotics, my country has one of the highest per capita antibiotic consumption rates in the world. Antibiotic emissions can easily lead to the formation of drug-resistant bacteria and resistance genes. Furthermore, antibiotics in wastewater have high biotoxicity, which can easily cause the collapse of biological treatment systems. For example, levofloxacin is a synthetic quinolone antibiotic with broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria. Coupled with its high efficacy and safety, it is widely produced and used worldwide. To avoid the impact of antibiotics in wastewater on biological systems and the associated environmental health risks, it is essential to remove them efficiently before they enter biological treatment systems.

[0003] Antibiotic production wastewater often contains high concentrations of antibiotic intermediates, which have low toxicity but often affect the removal of low-content, highly toxic antibiotics. However, antibiotics are a key factor affecting the stability of subsequent biological treatment systems. Therefore, the field of antibiotic wastewater treatment urgently needs to explore methods for selectively removing low-content antibiotics from antibiotic wastewater.

[0004] Biotechnology is a low-cost and currently mainstream technology for treating antibiotic wastewater. However, in the treatment of pharmaceutical wastewater, antibiotic residues can cause biotoxicity, leading to unstable biological treatment effects and the generation and release of large amounts of drug-resistant genes. Therefore, the key to solving the problem of antibiotic wastewater treatment is to selectively remove residual antibiotics using physicochemical techniques before biological treatment. Current pretreatment technologies for antibiotic wastewater mainly include coagulation sedimentation, Fenton oxidation, and plasma technology. These methods typically lack selectivity and have high chemical and energy consumption, resulting in low antibiotic removal efficiency and high costs.

[0005] This invention targets antibiotics in high-concentration acidic wastewater. To reduce biotoxicity, ensure efficient and low-cost selective removal of bioinhibitory substances like antibiotics, and simultaneously achieve organic acid reuse, this invention provides a method for the efficient and selective removal of antibiotics in high-concentration acidic wastewater. This method constructs a liquid coupling system between organic acid and oxidant molecules, allowing the organic acid to bond with the oxidant molecules, stabilizing the oxidant molecules, and altering the oxidative selectivity of the oxidant. The organic acid-coupled oxidant molecules specifically bind to the pharmacodynamic functional groups in the antibiotic structure of the wastewater, generating singlet oxygen and superoxide. The low oxidation potential of singlet oxygen and superoxide selectively oxidizes and destroys the pharmacodynamic functional groups of antibiotics in the wastewater, thereby selectively removing antibiotics and effectively reducing the toxicity of subsequent biological treatment systems. Simultaneously, the organic acid can be recycled and reused in constructing the organic acid-oxidant molecule coupling system, while the content of high-concentration pharmaceutical intermediates remains largely unchanged, serving as a carbon source for microbial utilization, thus reducing treatment costs. This method has significant implications for practical water treatment engineering applications and holds great promise in the fields of water treatment and resource recovery. Summary of the Invention

[0006] The purpose of this invention is to provide a method for the efficient and selective removal of antibiotics from high-concentration acidic wastewater. This method has almost 100% selectivity and removal rate for antibiotic degradation, and the organic acids can be recycled and reused. The residual organic intermediates can be used as carbon sources by organisms.

[0007] A method for removing antibiotics from high-concentration acidic wastewater according to the present invention includes:

[0008] 1) By adding organic acid and oxidant to a closed container with an inlet and an outlet, a liquid coupling system of organic acid coupled with oxidant molecules is formed, so that organic acid and oxidant molecules can bond, stabilize oxidant molecules, and change the oxidative selectivity of oxidant.

[0009] 2) High-concentration acidic wastewater is introduced into the sealed container, so that the organic acid coupled oxidant molecules in the liquid coupling system specifically bind to the pharmacodynamic functional groups in the structure of antibiotics in the high-concentration acidic wastewater, generating singlet oxygen and superoxide. The low oxidation potential of singlet oxygen and superoxide is used to selectively oxidize and destroy the pharmacodynamic functional groups of antibiotics in the wastewater, thereby selectively removing antibiotics and reducing biotoxicity.

[0010] 3) The solution after removing antibiotics from high-concentration acidic wastewater from the liquid coupling system is recycled from the outlet of the sealed container, and high-purity organic acids are recovered from the solution by electrodialysis and distillation.

[0011] 4) Utilize the recovered high-purity organic acids and oxidant molecules to reconstruct a coupling system for removing antibiotics from high-concentration acidic wastewater.

[0012] This invention employs a coupling method between organic acids and oxidants, enabling the organic acid and oxidant molecules to bond, stabilizing the oxidant molecules, and altering the oxidative selectivity of the oxidant. The organic acid-coupled oxidant molecules selectively bind to the pharmacodynamic functional groups of antibiotics in wastewater, generating singlet oxygen and superoxide. Utilizing the low oxidation potential of singlet oxygen and superoxide, selective removal of antibiotics from high-concentration acidic wastewater is achieved, while the content of coexisting high-concentration pharmaceutical organic intermediates remains essentially unchanged. These intermediates can serve as carbon sources for microbial utilization, preventing the collapse of the biological system and the release of drug-resistant bacteria and resistance genes. Furthermore, this invention uses aeration rods for spraying or dripping during the coupling process between the organic acid and oxidant, ensuring sufficient contact between the organic acid and oxidant, significantly reducing the amount of oxidant used and lowering costs. In addition, while ensuring sufficient dosage, it minimizes the inhibitory effect of residual oxidant on subsequent biological treatment.

[0013] Specifically, the above-mentioned method for efficiently and selectively removing antibiotics from high-concentration acidic wastewater includes the following steps:

[0014] 1) Add an organic acid with a volume concentration of 5%-20% to a sealed container with an inlet and an outlet, and inject the oxidant into the sealed container by spraying or dripping with an aeration rod; mix thoroughly for 2-5 minutes to form a liquid coupling system of organic acid coupled with oxidant molecules;

[0015] 2) High-concentration acidic wastewater with an antibiotic concentration of 0.5%-2% is introduced into the sealed container. The concentration ratio of oxidant to antibiotic is 0.1-1.0, so that the organic acid coupled oxidant molecules in the liquid coupling system specifically bind to the pharmacodynamic functional groups in the structure of antibiotics in the high-concentration acidic wastewater, generating singlet oxygen and superoxide. The reaction time of the coupling system with the high-concentration acidic wastewater is 2-10 minutes. The low oxidation potential of singlet oxygen and superoxide is used to selectively oxidize and destroy the pharmacodynamic functional groups of antibiotics in the wastewater, thereby selectively removing antibiotics and reducing biotoxicity.

[0016] 3) The solution after removing antibiotics from high-concentration acidic wastewater from the liquid coupling system is recycled from the outlet of the sealed container, and high-purity organic acids are recovered from the solution by electrodialysis and distillation.

[0017] 4) Utilize the recovered high-purity organic acids and oxidant molecules to reconstruct a coupling system for removing antibiotics from high-concentration acidic wastewater.

[0018] According to embodiments of the present invention, the organic acid is selected from any one of formic acid, acetic acid, propionic acid, malonic acid, or succinic acid.

[0019] According to an embodiment of the present invention, the oxidant is selected from ozone or hydrogen peroxide.

[0020] According to an embodiment of the present invention, the volume concentration of the above-mentioned organic acid is 5%-20%.

[0021] According to an embodiment of the present invention, the ozone is supplied by an ozone generator, and ozone is added to the solution through a microporous titanium aeration rod. The gas flow rate of ozone is controlled by a rotor flow meter to be 0.05-1.0 L / min. Hydrogen peroxide is injected by dripping at a rate of 1.0-10 μL / min.

[0022] According to an embodiment of the present invention, the concentration ratio of the oxidant to the antibiotic is 0.1-1.0.

[0023] According to an embodiment of the present invention, the antibiotic is one of a fluoroquinolone antibiotic or a sulfonamide antibiotic, the wastewater contains antibiotics, antibiotic chemical synthesis organic intermediates, etc., and the concentration of the antibiotic is 0.5%-2%.

[0024] According to an embodiment of the present invention, the reaction time between the above-mentioned coupling system and high-concentration acidic wastewater is 2-10 min.

[0025] The beneficial effects of this invention include:

[0026] This invention utilizes the coupling of organic acids and oxidant molecules to stabilize the oxidant molecules and alter their oxidative selectivity. This allows for selective and specific binding with the pharmacodynamic functional groups of antibiotics in wastewater, generating singlet oxygen and superoxide, thus selectively removing antibiotics. This method effectively reduces the antibiotic content in the system without altering the content of organic intermediates, demonstrating significant selectivity and efficacy. Furthermore, the organic intermediates can continue to serve as carbon sources for subsequent biological treatment systems, effectively reducing process costs and improving selective removal efficiency. In addition, this invention achieves near 100% selectivity and removal rate of antibiotics with a relatively low oxidant / antibiotic ratio and reaction time, while also enabling resource recovery of organic acids and the utilization of intermediates as carbon sources by microorganisms.

[0027] Therefore, this invention provides a method for the efficient and selective removal of antibiotics from high-concentration acidic wastewater. This method has good selectivity and removal rate for antibiotics in wastewater, and the organic acids can be recycled and reused. Residual intermediates can be used as carbon sources by subsequent microbial systems. Attached Figure Description

[0028] Figure 1 To assess the stability of the oxidant in the coupling system of organic acid and oxidant;

[0029] Figure 2 Characterization of the form of oxidant in the coupling system of organic acid and oxidant;

[0030] Figure 3 The role of ozone and antibiotics in a coupling system of organic acids and oxidants;

[0031] Figure 4 The selectivity and removal rate of antibiotics in the coupling system of organic acid and oxidant;

[0032] Figure 5 To evaluate the selective removal efficiency of antibiotics in high-concentration acidic wastewater by an organic acid-oxidant coupling system;

[0033] Figure 6 Characterization of the antimicrobial toxicity of antibiotics and intermediates; Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described in detail below with reference to specific embodiments:

[0035] Example 1:

[0036] A method for removing antibiotics from highly concentrated acidic wastewater includes the following steps:

[0037] 1) Add 10% organic acid acetic acid to a closed container with an inlet and an outlet. Add 25 mg / L ozone oxidant to the closed container by spraying through an aeration rod. After mixing thoroughly for 5 minutes, a coupling system of acetic acid and ozone oxidant molecules is obtained.

[0038] 2) High-concentration acidic wastewater from the production of levofloxacin, a fluoroquinolone antibiotic, with an antibiotic concentration of 1% was injected into the aforementioned closed container. The concentration ratio of oxidant to antibiotic was 0.25, and the reaction time was 10 minutes. This allowed the organic acid-coupled oxidant molecules in the liquid coupling system to specifically bind with the pharmacodynamic functional groups in the antibiotic structure of the high-concentration acidic wastewater, generating singlet oxygen and superoxide. The low oxidation potential of singlet oxygen and superoxide was used to selectively oxidize and destroy the pharmacodynamic functional groups of antibiotics in the wastewater, thereby selectively removing antibiotics and reducing biotoxicity.

[0039] 3) The solution after removing antibiotics from the high-concentration acidic wastewater from the liquid coupling system is recycled from the outlet of the sealed container, and high-purity organic acid acetic acid is recovered from the solution by electrodialysis and distillation.

[0040] 4) The recovered high-purity organic acid acetic acid and ozone oxidant molecules are used to reconstruct a coupled system for removing antibiotics from high-concentration acidic wastewater.

[0041] Comparative Example 1:

[0042] The difference from Example 1 is that the inorganic acid sulfuric acid is used instead of the organic acid acetic acid.

[0043] Comparative Example 2:

[0044] The difference from Example 1 is that water is used instead of the organic acid acetic acid.

[0045] Experimental Example 1:

[0046] Oxidant stability test

[0047] Ozone oxidant is added to water or organic acid solution by spraying through an aeration rod. The concentration of ozone oxidant in the solution is determined by iodometric titration, which includes sampling, titration with sodium thiosulfate, and concentration calculation.

[0048] The above tests were performed on the coupling system of acetic acid and ozone oxidant molecules in Example 1 and Comparative Example 2, as well as the stability of ozone oxidant molecules in aqueous solution. The results are as follows: Figure 1 As shown. By Figure 1 It can be seen that, compared with Comparative Example 2, the decomposition rate of ozone oxidant in Example 1 is significantly reduced by coupling with acetic acid, that is, the molecular stability of ozone oxidant is significantly improved.

[0049] Experimental Example 2:

[0050] Characterization of the form of oxidant

[0051] The oxidant in solution was determined using an electron paramagnetic resonance spectrometer (ESR, ESP 300E, Bruker), with a microwave frequency of 9.85 GHz, a microwave power of 2.21 mW, a central field strength of 3504.07 G, and a tuning frequency of 100.00 kHz.

[0052] The above tests were performed on the coupling system of acetic acid and ozone oxidant molecules in Example 1, and the form of ozone oxidant in aqueous solution. The results are as follows: Figure 2 As shown. By Figure 2 It is known that ozone exists in the form of oxidant molecules in the acetic acid-ozone coupling system, and no other oxygen species are produced. Therefore, the ozone oxidant can be stably maintained in the form of oxidant molecules through coupling with the organic acid acetic acid.

[0053] Experimental Example 3:

[0054] Oxidizing agent and antibiotic interaction test

[0055] Hydroxyl radical scavenger, superoxide scavenger, and singlet oxygen scavenger were added to the reaction solution, and the changes in antibiotic concentration were measured by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS, Waters).

[0056] The above tests were performed on the coupling system of acetic acid and ozone oxidant molecules in Example 1 and Comparative Example 2, and on the interaction between ozone oxidant and the antibiotic levofloxacin in aqueous solution. The results are as follows: Figure 3 As shown. By Figure 3 As can be seen, compared with Comparative Example 2, in Example 1, the acetic acid and ozone oxidant molecular coupling system reacts with antibiotics to generate singlet oxygen and superoxide. The low oxidation potential of singlet oxygen and superoxide participates in subsequent reactions to enhance the selectivity of antibiotic removal. In the aqueous solution, ozone reacts with antibiotics to generate hydroxyl radicals, superoxide, and singlet oxygen. Since the oxidation potential of hydroxyl radicals is very high, they can degrade antibiotics and intermediates non-selectively.

[0057] Experimental Example 4:

[0058] Antibiotic selectivity and removal rate

[0059] The concentrations of antibiotics and intermediates were determined using ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS, Waters).

[0060] The above tests were performed on the coupling system of acetic acid and ozone oxidant molecules in Example 1, Comparative Example 1, and Comparative Example 2, as well as the selectivity and removal rate of ozone oxidants for antibiotics in inorganic acids and aqueous solutions. The results are as follows: Figure 4 As shown. By Figure 4 It can be seen that, compared with Comparative Examples 1 and 2, the coupling system of acetic acid and ozone oxidant molecules in Example 1 has nearly 100% selectivity for the removal of the antibiotic levofloxacin, with a removal rate of nearly 100% in 10 minutes. In inorganic acids and aqueous solutions, antibiotics and the intermediate levofloxacin are degraded simultaneously without selectivity. Therefore, the coupling system of organic acid acetic acid and ozone oxidant molecules achieves selective removal of antibiotics.

[0061] Experimental Example 5:

[0062] Selective removal of antibiotics from high-concentration acidic wastewater

[0063] Non-targeted recognition, targeted concentration determination, and selectivity testing of antibiotics and intermediates in high-concentration acidic wastewater were performed using an ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometer (UPLC-QTOF-MS, Waters) in ESI positive ion mode. The concentrations of antibiotics and intermediates were then determined using UPLC-MS, Waters.

[0064] The high-concentration acidic wastewater sample from Example 1 was subjected to the above tests, and the results are as follows: Figure 5 As shown. By Figure 5It is known that the main pollutants in the wastewater are levofloxacin and levofluorocarboxylic acid, with concentrations of 82.87 mg / L and 7980.19 mg / L, respectively. The molecular coupling system of organic acid acetic acid and ozone oxidant achieved a removal rate of over 90% for levofloxacin in high-concentration acidic wastewater, while the concentration of levofluorocarboxylic acid remained essentially unchanged. Therefore, the molecular coupling system of organic acid acetic acid and ozone oxidant exhibits a highly significant selective effect on antibiotics in the complex components of high-concentration acidic wastewater.

[0065] Experimental Example 6:

[0066] Potency and toxicity characterization of antibiotics and intermediates

[0067] Using Staphylococcus aureus as an indicator strain, the absorbance at 580 nm was measured using a turbidimeter (WBS-101) to test the antimicrobial activity of antibiotics and intermediates.

[0068] The above tests were performed on the antibiotic levofloxacin and its intermediate levofluorocarboxylic acid in Example 1, and the results are as follows: Figure 6 As shown. By Figure 6 It is known that the antibiotic levofloxacin in the wastewater from levofloxacin production has the highest toxicity, while the intermediate levofloxacin carboxylic acid has lower toxicity and can be used as a carbon source for subsequent biological treatment systems.

[0069] The conventional techniques described in the above embodiments are existing technologies known to those skilled in the art, and therefore will not be described in detail here.

[0070] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for removing antibiotics from high-concentration acidic wastewater, comprising: Add organic acid and oxidant to a sealed container with an inlet and an outlet, and mix thoroughly for 2-5 minutes. ， This allows organic acids to bond with oxidant molecules, stabilize oxidant molecules, and alter the oxidative selectivity of oxidants, forming a liquid coupling system of organic acid-coupled oxidant molecules for the selective removal of antibiotics from high-concentration acidic wastewater. High-concentration acidic wastewater is introduced into the sealed container and reacted with the coupling system for 2-10 minutes. This allows the organic acid-coupled oxidant molecules in the liquid coupling system to specifically bind with the pharmacodynamic functional groups in the antibiotic structure of the high-concentration acidic wastewater, generating singlet oxygen and superoxide. The low oxidation potential of singlet oxygen and superoxide is used to selectively oxidize and destroy the pharmacodynamic functional groups of antibiotics in the wastewater, thereby selectively removing antibiotics and reducing biotoxicity. The solution after removing antibiotics from high-concentration acidic wastewater from the liquid coupling system is recycled from the outlet of the sealed container, and high-purity organic acids are recovered from the solution using electrodialysis and distillation methods. The recovered high-purity organic acids and oxidant molecules were used to reconstruct a liquid coupling system of organic acid-coupled oxidant molecules for the selective removal of antibiotics from high-concentration acidic wastewater; The organic acid is selected from any one of formic acid, acetic acid, propionic acid, malonic acid, or succinic acid; the oxidant is an ozone oxidant.

2. The method for removing antibiotics from high-concentration acidic wastewater according to claim 1, characterized in that: The volume concentration of the organic acid added to the sealed container is 5%-20%; the oxidant is injected into the sealed container using an aeration rod spray method.

3. The method for removing antibiotics from high-concentration acidic wastewater according to claim 1, characterized in that: The antibiotic is one of the fluoroquinolone antibiotics or sulfonamide antibiotics.

4. The method for removing antibiotics from high-concentration acidic wastewater according to claim 1, characterized in that: The high-concentration acidic wastewater contains antibiotics and organic intermediates for antibiotic chemical synthesis.

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