A method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater and its application

Abstract

The present invention belongs to the technical field of wastewater treatment, and more particularly to a method and application of anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater. The method comprises the following steps: S1, adding anaerobic digestion sludge and cometabolism sludge to a sequencing batch reactor; the cometabolism sludge is an anaerobic sludge of degradable ceftriaxone sodium obtained by taming simulated wastewater mixed with ceftriaxone sodium and glucose; S2, adding the wastewater to be treated to a sequencing batch reactor for anaerobic biodegradation; the wastewater to be treated contains ceftriaxone sodium and does not contain cometabolism substrates. The present invention uses cometabolism sludge tamed by cometabolism of ceftriaxone sodium and glucose for bio-enhancement, and the types and quantities of functional microorganisms are greatly increased, which is beneficial to improving the efficiency of biodegradation of ceftriaxone sodium and improving the treatment effect of the reactor, and there is no need to add a large amount of cometabolism substrates such as glucose in the anaerobic biodegradation stage, which greatly reduces the cost of wastewater treatment.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater and application thereof. Background Art

[0002] Since the 20th century, antibiotics have been widely used in medical and aquaculture industries, but a considerable portion of them are not fully utilized or absorbed, and are excreted from the body in the form of drug prototypes or metabolites with human or animal feces. Antibiotics in the environment can induce environmental toxicological effects. Antibiotics, as metabolites produced by microorganisms such as bacteria, fungi and actinomycetes, can inhibit the growth of other microorganisms by hindering the synthesis of bacterial macromolecules and destroying bacterial cell structures. They can also induce bacterial resistance, which seriously affects human, animal and plant health and endangers ecological safety. Currently, commonly used antibiotics mainly include β-lactams, sulfonamides, fluoroquinolones, tetracyclines and other types. Cephalosporins, as the most commonly used β-lactam antibiotics in clinical practice, have the advantages of strong antibacterial activity, wide indications, stability to some β-lactamases and long elimination half-life, and are therefore widely used.

[0003] Research on the treatment of wastewater containing ceftriaxone sodium mainly focuses on electrochemical catalytic oxidation and photocatalysis. However, these physical and chemical methods for treating antibiotics have problems such as high cost and secondary pollution. The effect of ordinary biological treatment is limited, so improving the biodegradation efficiency of ceftriaxone sodium needs further research. At present, the degradation efficiency of antibiotics in the biological treatment process can be enhanced by using methods such as bioaugmentation and cometabolism.

[0004] Bioaugmentation is a typical biological treatment technology that increases the degradation rate of organic matter by adding specific types of functional microorganisms. However, in the process of anaerobic biodegradation of ceftriaxone sodium, the reproduction, growth and activity of anaerobic microorganisms will be affected by the wastewater microenvironment, resulting in poor degradation of the target substance. The cometabolism technology increases the number of functional microorganisms by adding cometabolism substrates, thereby better degrading the target pollutants. However, the existing technology usually requires the addition of a large amount of cometabolism substrates, which increases the treatment cost and is not conducive to the promotion and application of this technology. Summary of the invention

[0005] In view of this, the present invention provides a method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater and its application, aiming to solve or at least alleviate the technical problems of low degradation rate of ceftriaxone sodium or large consumption of co-metabolism substrates caused by functional microbial enhancement in the prior art. It is specifically achieved by the following technical solutions:

[0006] The present invention provides a method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater, comprising the following steps:

[0007] S1. Adding anaerobic digestion sludge and cometabolism sludge into a sequencing batch reactor; wherein the anaerobic digestion sludge is inoculated sludge, and the cometabolism sludge is anaerobic sludge that is obtained by acclimating simulated wastewater mixed with ceftriaxone sodium and glucose and is capable of degrading the ceftriaxone sodium;

[0008] S2. Adding the wastewater to be treated into the sequencing batch reactor for anaerobic biodegradation; wherein the wastewater to be treated contains the ceftriaxone sodium and does not contain a co-metabolism substrate.

[0009] Furthermore, in step S1, the method for preparing anaerobic digestion sludge includes: placing the anaerobic sludge in a mixed solution for acclimatization for a period of time; wherein the mixed solution contains anaerobic biogas slurry and glucose, and the COD of the mixed solution is 800-1200 mg / L.

[0010] Furthermore, in step S1, the method for preparing the cometabolic sludge includes: placing the anaerobic sludge in a mixture of ceftriaxone sodium and glucose simulated wastewater for acclimation for a period of time; wherein the concentration of ceftriaxone sodium in the mixture of ceftriaxone sodium and glucose simulated wastewater is 200±20 mg / L, and the concentration of glucose is 80±5 mg / L.

[0011] Furthermore, in step S1, the sludge concentration ratio of the anaerobic digestion sludge to the cometabolic sludge is 4:1.

[0012] Furthermore, the sludge concentration of the anaerobic digestion sludge is 4000±200 mg / L, and the sum of the sludge concentrations of the cometabolic sludge and the anaerobic digestion sludge is 5000±200 mg / L.

[0013] Furthermore, in step S2, in the wastewater to be treated, the initial concentration of ceftriaxone sodium is 200±20 mg / L.

[0014] Furthermore, in step S2, when the anaerobic biodegradation is carried out, the culture temperature is controlled to be 35±2° C. and the initial pH of the reaction is controlled to be 7.5±0.3.

[0015] Furthermore, in step S2, when the anaerobic biodegradation is carried out, the drainage ratio of the sequencing batch reactor is 20% and the hydraulic retention time is 8 hours.

[0016] In addition, the present invention also provides the use of the above-mentioned method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater in degrading ceftriaxone sodium in wastewater.

[0017] The advantages and positive effects of the present invention are:

[0018] The present invention uses anaerobic sludge domesticated by a ceftriaxone sodium and glucose cometabolism system to perform bio-augmentation on anaerobic digestion sludge. After the cometabolism sludge is domesticated by glucose cometabolism, the types and quantities of functional microorganisms in the cometabolism sludge are greatly increased, which is beneficial to improving the efficiency of biodegradation of ceftriaxone sodium and improving the treatment effect of the reactor. There is no need to add a large amount of cometabolism substrates such as glucose in the anaerobic biodegradation stage, which greatly reduces the cost of wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 The concentration change curve and degradation efficiency of ceftriaxone sodium in the SBR reactor of Example 1 of the present invention at different operation stages;

[0021] Figure 2 This is a diagram showing the average degradation effect of ceftriaxone sodium in the SBR reactor of Example 1 of the present invention at different operation stages;

[0022] Figure 3 This is a diagram showing the degradation effect of ceftriaxone sodium by the cometabolic sludge of Example 1 of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the examples. The equipment and reagents used in each embodiment and test example can be obtained from commercial sources unless otherwise specified. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Based on the information contained in this application, it is easy for those skilled in the art to make various changes to the precise description of the present invention without departing from the spirit and scope of the appended claims. It should be understood that the scope of the present invention is not limited to the defined process, properties or components, because these embodiments and other descriptions are only for illustrating specific aspects of the present invention. In fact, various changes that the technicians in this field or related fields can obviously make to the embodiments of the present invention are all covered within the scope of the appended claims.

[0025] In order to better understand the present invention but not to limit the scope of the present invention, all the numbers used in this application to express the amount, ratio, and other numerical values ​​should be understood as modified by the word "about" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification and the attached claims are approximate values, which may be changed according to the different ideal properties attempted to be obtained. Each numerical parameter should at least be regarded as obtained based on the reported significant figures and by conventional rounding methods.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] This embodiment provides a method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater, comprising the following steps:

[0028] S1. Adding anaerobic digestion sludge and cometabolism sludge into a sequencing batch reactor (SBR reactor); wherein the anaerobic digestion sludge is inoculated sludge, and the cometabolism sludge is anaerobic sludge that is obtained by acclimating simulated wastewater mixed with ceftriaxone sodium and glucose and is capable of degrading the ceftriaxone sodium;

[0029] S2. Adding the wastewater to be treated into the sequencing batch reactor for anaerobic biodegradation; wherein the wastewater to be treated contains the ceftriaxone sodium and does not contain a co-metabolism substrate.

[0030] Although traditional physical and chemical treatment has a good degradation effect on ceftriaxone sodium, the treatment cost is high and is not conducive to promotion, and traditional anaerobic biological treatment has a poor degradation effect on ceftriaxone sodium; the present invention uses anaerobic sludge domesticated by ceftriaxone sodium and glucose cometabolism system to bio-enhance anaerobic digestion sludge, and the cometabolism sludge is domesticated by glucose cometabolism, and the types and numbers of functional microorganisms therein are greatly increased, which is conducive to improving the efficiency of biodegradation of ceftriaxone sodium and improving the treatment effect of the reactor, and there is no need to add a large amount of cometabolism substrates such as glucose in the anaerobic biodegradation stage, which greatly reduces the cost of wastewater treatment. The present invention reduces the amount of cometabolism substrates while maintaining high ceftriaxone sodium degradation efficiency by adding cometabolism sludge domesticated by glucose cometabolism, and the wastewater treatment cost is low, which has guiding and reference significance for degrading other antibiotics in antibiotic wastewater.

[0031] Optionally, in step S1, the method for preparing the anaerobic digestion sludge comprises: placing the anaerobic sludge in a mixed solution for acclimatization for a period of time to obtain the anaerobic digestion sludge; wherein the mixed solution contains anaerobic biogas slurry and glucose, and the COD of the mixed solution is 800-1200 mg / L.

[0032] Generally speaking, anaerobic sludge is placed in a mixed solution and acclimatized for 50-70 days to obtain anaerobic sludge with good hydrolysis and acidification performance. Using this sludge as anaerobic digestion sludge, i.e., the inoculated sludge of the present invention, can improve the degradation effect of ceftriaxone sodium.

[0033] Optionally, in step S1, the method for preparing the cometabolic sludge includes: placing the anaerobic sludge in a mixture of ceftriaxone sodium and glucose simulated wastewater for acclimation for a period of time; wherein the concentration of ceftriaxone sodium in the mixture of ceftriaxone sodium and glucose simulated wastewater is 200±20 mg / L, and the concentration of glucose is 80±5 mg / L.

[0034] Generally speaking, anaerobic sludge is placed in a simulated wastewater mixed with ceftriaxone sodium and glucose for acclimatization for 15-25 days to obtain anaerobic sludge that can efficiently degrade ceftriaxone sodium, which is the cometabolic sludge used in the present invention.

[0035] Optionally, in step S1, the sludge concentration ratio of the anaerobic digestion sludge to the cometabolic sludge is 4:1.

[0036] Specifically, the sludge concentration of the anaerobic digestion sludge is 4000±200 mg / L, and the sum of the sludge concentrations of the cometabolic sludge and the anaerobic digestion sludge is 5000±200 mg / L, that is, the sludge concentration of the SBR reactor during operation is 5000±200 mg / L.

[0037] Optionally, in step S2, in the wastewater to be treated, within one cycle, the initial concentration of ceftriaxone sodium is 200±20 mg / L.

[0038] Optionally, in step S2, when performing the anaerobic biodegradation, the culture temperature is controlled to be 35±2° C. and the initial reaction pH is controlled to be 7.5±0.3.

[0039] Optionally, in step S2, when the anaerobic biodegradation is carried out, within one cycle, the drainage ratio of the SBR reactor is 20% and the hydraulic retention time is 8 hours.

[0040] The operation of an SBR reactor includes five stages in one cycle, namely, water inlet, reaction, precipitation, water outlet and idleness. The time between water inlet and water outlet is the hydraulic retention time. Anaerobic digestion sludge and co-metabolism sludge are added to the SBR reactor, and then the wastewater to be treated is added. After stirring and reacting, precipitation is carried out, and then the supernatant accounting for 20% of the reactor volume (i.e., the drainage ratio mentioned above) is discharged, and then the SBR reactor is idle for a period of time, such as 16 hours. This process is a cycle of anaerobic biodegradation. Generally speaking, there is one cycle per day. After one cycle, the SBR reactor is replenished with an inlet of the same volume as the drainage volume to keep the wastewater volume in the SBR reactor unchanged, and the initial concentration of ceftriaxone sodium is controlled to 200±20mg / L to carry out the next cycle of anaerobic biodegradation; when actually treating wastewater, multiple cycles of anaerobic biodegradation are usually required.

[0041] Based on the same inventive concept, another embodiment of the present invention provides the use of the above-mentioned method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater in degrading ceftriaxone sodium in wastewater.

[0042] The application of the method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater in degrading ceftriaxone sodium in wastewater has the same advantages as the method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater described above over the prior art, which will not be repeated here.

[0043] The present invention is further described below in conjunction with specific examples. The experimental methods in the following examples without specifying specific conditions are generally carried out according to the conditions recommended by the manufacturer.

[0044] Example 1

[0045] A method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater, comprising the following steps:

[0046] S1. Adding anaerobic digestion sludge and cometabolism sludge into the SBR reactor, the concentration ratio of anaerobic digestion sludge to cometabolism sludge is 4:1; specifically, the sludge concentration of anaerobic digestion sludge is 4000±200 mg / L, and the total sludge concentration of the SBR reactor is 5000±200 mg / L;

[0047] The anaerobic digestion sludge is inoculated sludge, and the preparation method includes: placing ordinary anaerobic sludge in a mixed solution (containing anaerobic biogas slurry and glucose, COD=about 1000 mg / L) for 60 days to obtain anaerobic sludge with good hydrolysis and acidification performance.

[0048] The cometabolism sludge is an anaerobic sludge that can degrade ceftriaxone sodium and is obtained by acclimating the simulated wastewater mixed with ceftriaxone sodium and glucose. The preparation method includes: placing ordinary anaerobic sludge in the simulated wastewater mixed with ceftriaxone sodium and glucose, controlling the sludge concentration in the SBR reactor to be 5000±200 mg / L and the initial ceftriaxone sodium concentration to be 200±20 mg / L and the glucose concentration to be 80±5 mg / L, then setting the temperature to 35°C, the initial reaction pH to 7.5, the stirring speed to 60r / min, and the drainage ratio to 20%, and carrying out the cometabolism acclimation of ceftriaxone sodium and glucose under the above conditions. One cycle is carried out per day, and a total of 20 cycles are reacted to obtain cometabolism sludge. Samples are taken at the beginning of each reaction and at the end of 8h of the reaction, and the concentration of ceftriaxone sodium is detected by taking the inlet and outlet water each time. The measurement results are shown in the table. Figure 3 .

[0049] To simplify the operation, after the anaerobic digestion sludge acclimation is completed, 1 / 5 of the anaerobic sludge in the SBR reactor is taken out, and then an equal amount of cometabolic sludge is added to obtain the SBR reactor and sludge system of step S1 of the present invention.

[0050] S2. Add the untreated wastewater containing 200±20 mg / L ceftriaxone sodium and no co-metabolism substrate-glucose into the SBR reactor, and then set the temperature to 35°C, the initial pH of the reaction to 7.5, the stirring speed to 60r / min, and the drainage ratio to 20% to carry out anaerobic biodegradation of ceftriaxone sodium; take samples at the beginning of each reaction and after 8 hours of reaction, and continue the reaction for 28 cycles. Take the inlet and outlet water at the beginning of each cycle and after 8 hours of reaction to detect the concentration of ceftriaxone sodium. The measurement results are shown in Figure 1 Biofortification stage.

[0051] The reactor system without the addition of cometabolic sludge was used as a control, and the remaining operations were the same as the above step S2, namely: the anaerobic digested sludge was inoculated into a 5L SBR reactor, and ceftriaxone sodium simulated wastewater was added, the wastewater contained ceftriaxone sodium and did not contain glucose, the sludge concentration in the reactor was controlled to be 5000±200mg / L and the initial ceftriaxone sodium concentration was 200±20mg / L, and then the temperature was set to 35°C, the initial reaction pH was 7.5, the stirring speed was 60r / min, and the drainage ratio was 20%, and the anaerobic biodegradation of ceftriaxone sodium was carried out under the above conditions. One cycle was carried out per day, and a total of 28 cycles were reacted. The inlet and outlet water of each cycle were taken for ceftriaxone sodium concentration detection. The measurement results are shown in Figure 1 Middle control stage.

[0052] according to Figure 1The average degradation rate of ceftriaxone sodium in the control stage was calculated to be 35.25±3.60%, and the average degradation rate of ceftriaxone sodium in the biofortification stage was 56.31±2.39% (see Figure 2 ).

[0053] According to the above test results, bio-augmentation by the cometabolic sludge of the present invention can improve the anaerobic biodegradation effect of ceftriaxone sodium in wastewater. At the same time, compared with the average degradation rate of 57.24±3.49% of the cometabolic sludge system, although the degradation effect of the present invention on ceftriaxone sodium remains similar, there is no need to add the cometabolic substrate glucose, which can significantly save the amount of glucose and reduce the cost of biodegradation treatment of antibiotic wastewater.

[0054] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater, characterized in that: The following steps are involved: S1. Adding anaerobic digestion sludge and cometabolic sludge into a sequencing batch reactor, wherein the sludge concentration ratio of the anaerobic digestion sludge to the cometabolic sludge is 4:1; The anaerobic digestion sludge is inoculated sludge, and the preparation method of the anaerobic digestion sludge comprises: placing the anaerobic sludge in a mixed solution for acclimation for a period of time, wherein the mixed solution contains anaerobic biogas slurry and glucose; the cometabolism sludge is anaerobic sludge that can degrade the ceftriaxone sodium obtained by acclimation in simulated wastewater mixed with ceftriaxone sodium and glucose, and the preparation method of the cometabolism sludge comprises: placing the anaerobic sludge in simulated wastewater mixed with ceftriaxone sodium and glucose for acclimation for a period of time; S2, adding the wastewater to be treated into the sequencing batch reactor for anaerobic biodegradation; Wherein, the wastewater to be treated contains the ceftriaxone sodium but does not contain a cometabolic substrate, and the cometabolic substrate is glucose.

2. The method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: In step S1, the COD of the mixed solution is 800-1200 mg / L.

3. The method for anaerobic biological enhancement degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: In step S1, the concentration of ceftriaxone sodium in the simulated wastewater mixed with glucose is 200±20 mg / L, and the concentration of glucose is 80±5 mg / L.

4. The method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: The sludge concentration of the anaerobic digestion sludge is 4000±200 mg / L, and the sum of the sludge concentrations of the cometabolic sludge and the anaerobic digestion sludge is 5000±200 mg / L.

5. The method for anaerobic bio-enhanced degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: In step S2, in the wastewater to be treated, the initial concentration of ceftriaxone sodium is 200±20 mg / L.

6. The method for anaerobic biological enhancement degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: In step S2, when the anaerobic biodegradation is performed, the culture temperature is controlled to be 35±2° C. and the initial pH of the reaction is controlled to be 7.5±0.

3.

7. The method for anaerobic bioaugmented degradation of ceftriaxone sodium in wastewater according to claim 1, characterized in that: In step S2, when the anaerobic biodegradation is carried out, the drainage ratio of the sequencing batch reactor is 20% and the hydraulic retention time is 8 hours.

8. Use of the method for anaerobic biological enhanced degradation of ceftriaxone sodium in wastewater according to any one of claims 1 to 7 in degrading ceftriaxone sodium in wastewater.

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