CN106587445B - Pretreatment method of antibiotic production wastewater - Google Patents

Abstract

The pretreatment method of the antibiotic production wastewater is characterized by comprising the following steps: the method comprises the following steps: 1) primary micro-electrolysis; 2) primary coagulating sedimentation; 3) advanced electrocatalytic oxidation; 4) secondary micro-electrolysis; 5) and (5) performing secondary coagulating sedimentation. The invention mainly aims at the defects of the prior method for pretreating the wastewater in the antibiotic production process, has high treatment efficiency and low treatment cost, and the COD and the chromaticity of the antibiotic production wastewater treated by the process can reach the standard.

Description

Pretreatment method of antibiotic production wastewater

Technical field:

The invention belongs to the field of wastewater treatment, and in particular relates to a treatment method for antibiotic production wastewater.

Background technique:

At present, my country has become one of the major producers of antibiotic preparations in the world. The wastewater produced by the production of antibiotics often contains a wide variety of organic pollutants with high concentrations (COD is 5000-80000 mg/L), most of which are difficult to biochemically degrade directly, resulting in a long retention time in the environment, which is harmful to the environment. create pollution. Antibiotic production wastewater also contains "three causes" (carcinogenic, teratogenic, mutagenic) organic pollutants, even if its concentration in the water body is lower than level ^10-9 , it is still very harmful to human health. So far, no suitable solution has been found for the treatment of these organic wastewaters with various organic substances and complex components, which is the difficulty and hot spot of water treatment at home and abroad.

In my country, the pretreatment methods used by antibiotic manufacturers are mainly physicochemical methods. When using the physicochemical method to treat high-concentration antibiotic production wastewater, there are problems such as large dosage of chemical reagents and insignificant treatment effect. At the same time, a large number of chemical reagents are easy to cause secondary pollution to the environment, and during subsequent biochemical reactions, if the COD of the influent water is too high, the influent water needs to be diluted, resulting in a larger final water output and serious water resources. waste. Therefore, it is particularly important to find an economical, environmentally friendly, efficient and stable pretreatment process for antibiotic production wastewater, which is of great significance to the production of antibiotics and environmental protection in my country.

Invention content:

Purpose of the invention: The present invention provides a kind of pretreatment method of antibiotic production wastewater, and its purpose is to solve the problems that existed in the past.

Technical solutions:

The pretreatment method of antibiotic production wastewater is characterized in that: the method comprises the following steps:

1) first-level micro-electrolysis;

2) Initial coagulation and sedimentation;

3) Advanced electrocatalytic oxidation;

4) Secondary micro-electrolysis;

5) Secondary coagulation sedimentation.

The antibiotic is azithromycin.

A kind of azithromycin production wastewater is the mixed effluent of each production process wastewater.

The device for implementing the above treatment method is composed of a primary micro-electrolysis reactor, a primary coagulation and sedimentation tank, an electrocatalytic oxidation reaction generator, a secondary micro-electrolysis reactor and a secondary coagulation and sedimentation tank.

The method includes the following steps:

The specific operation steps and specific operation techniques are as follows:

(1) First-level micro-electrolysis: After the antibiotic production wastewater enters the regulating tank, the wastewater is temporarily stored and homogenized in the regulating tank, and the pH is adjusted to 3.0-5.0, and then enters the first-level micro-electrolysis reactor for redox and primary batteries. Reaction, aeration is carried out during the reaction process, so that the waste water and the filler can be fully contacted, and the reaction is more sufficient;

(2) Initial coagulation and precipitation: After the antibiotic production wastewater undergoes the first-level micro-electrolysis reaction, the effluent contains a large amount of Fe ^{2 +} , which needs to be removed, otherwise it will affect the advanced electrocatalytic oxidation reaction in the next stage, and adjust the pH of the effluent. When it reaches ≥9.0, enter the vertical flow primary coagulation sedimentation tank, add a certain amount of PAC and PAM to cause Fe ²⁺ to flocculate with PAC and PAM in the form of Fe(OH) ₂ to produce precipitation, and the precipitation time is 30-60min; After micro-electrolysis and initial coagulation and precipitation, the small molecular organic pollutants in the wastewater are rapidly degraded, the COD value of the wastewater is reduced, and the suspended particles in the wastewater are also removed;

(3) Advanced electrocatalytic oxidation: adjust the pH of the effluent from the primary coagulation sedimentation tank to 3.0 to 5.0, and directly enter the electrocatalytic reaction generator. The electrode consists of 3 anodes and 2 cathodes, the distance between electrodes is 25mm, the current density is 20mA/cm ² , and the reaction time is 4h; the pollutants are electrochemically oxidized and burned on the surface of the electrodes, and part of the pollutants are converted into easily accessible microorganisms. The other part of the degraded substances is oxidized into inorganic substances such as H ₂ O and CO ₂ , and the intermediates generated by the electrochemical reaction process are used to further oxidize the pollutants, so that the polycyclic macromolecular organic pollutants undergo ring-opening phenomenon. for subsequent processing;

(4) Secondary micro-electrolysis: adjust the pH of the wastewater after the electrocatalytic oxidation reaction to 3.0-5.0, and enter the secondary micro-electrolysis reactor. During the reaction process, aeration is carried out, so that the wastewater and the filler can be fully contacted, and the reaction is more sufficient; After electrocatalytic oxidation reaction, most of the polycyclic aromatic macromolecular compounds in wastewater are oxidized and ring-opened to form small organic pollutants; refractory organic compounds and residual antibiotics or broken double bonds, or decomposed into complex macromolecular structures Straight-chain small molecule structure; therefore, the small molecule organic pollutants are further degraded through the secondary micro-electrolysis reaction, so that the B/C is increased, and the subsequent biochemical treatment requirements are met;

(5) Secondary coagulation and precipitation: a large amount of Fe ²⁺ contained in the wastewater after the secondary micro-electrolysis treatment will affect the subsequent biochemical treatment and easily cause corrosion of the pipeline. Therefore, adjust the pH of the effluent ≥ 9.0 to make Fe ²⁺ generates Fe(OH) ₂ and flocculates with PAC and PAM to finally produce precipitation, and the precipitation time is 1h.

(1) The COD of the wastewater produced by antibiotics in the step is 40000-50000 mg/L.

(1) The filling rate of the filler in the first-stage micro-electrolysis reactor in the step is 30% to 50%, and the reaction time is 5h.

The intermediate produced by the electrochemical reaction process is active chlorine produced by adding NaCl.

(4) In the step, the filling rate of the filler in the secondary micro-electrolysis reactor is 30% to 50%, and the reaction time is 5h.

(5) After the step, most of the suspended particles have been removed, the chromaticity of the wastewater is significantly reduced, and the COD of the wastewater reaches about 10,000 mg/L, which greatly reduces the pressure of the subsequent biochemical treatment and the increase in B/C is beneficial to the subsequent biochemical treatment.

Advantages and effects: the present invention provides a kind of pretreatment method of antibiotic production wastewater, the present invention is mainly aimed at the deficiency of the current antibiotic production process wastewater pretreatment method, its treatment efficiency is high, the treatment cost is low, the antibiotic production wastewater treated by this process The COD and chromaticity can meet the standard.

The indexes and determination methods of the present invention: chemical oxygen demand (COD) is determined by rapid digestion spectrophotometry (HJ/T399-2007); ammonia nitrogen (NH ₃ -N) is determined by Nessler reagent spectrophotometry (HJ535 -2009); biochemical oxygen demand (BOD ₅ ) adopts dilution and inoculation method (HJ505-2009); wastewater biodegradability index (B/C) is the ratio of BOD ₅ to COD _Cr .

Compared with the prior art, the wastewater pretreatment process of the present invention has the following characteristics:

(1) The micro-electrolysis reaction adopts the self-developed new structured packing, which is melted at high temperature to form an integrated alloy, which can ensure the continuous and efficient redox reaction of the primary battery, and avoid the separation of cathode and anode after a period of reaction, which will affect the primary battery reaction. The high-temperature preparation process increases the porosity of the filler, provides a large specific surface area, enhances the reaction activity, and is not easy to passivate and harden, so that the reaction can run stably and efficiently for a long time.

(2) The regular packing replacement frequency is low, the packing loss rate is 10%-15%, it can be replenished once a year, and the processing cost is low. In addition, while reducing the concentration of pollutants in the wastewater, the micro-electrolysis technology correspondingly improves the biodegradability of the wastewater, and the micro-electrolysis technology is easy to combine with other pretreatment technologies, and the effect is good and the effect is quick.

(3) By combining with advanced electrocatalytic oxidation technology. First-level micro-electrolysis is easy to oxidize and remove small molecular organic pollutants and reduce part of the COD of wastewater; after advanced electrocatalytic oxidation treatment, refractory organic matter and residual antibiotics in wastewater or broken double bonds, or decomposed into complex macromolecular structures The linear chain can further remove COD in the wastewater; finally, through the secondary micro-electrolysis treatment, most of the small molecular organic compounds in the wastewater are further removed, and finally all toxic and harmful organic pollutants are removed, and the biodegradability of the wastewater is further improved. The high-level micro-electrolysis technology and the advanced electro-catalytic oxidation technology are organically and closely combined and linked together, so that the final effluent meets various indicators.

(4) Advanced electrocatalytic oxidation technology can usually operate efficiently at room temperature. The operating parameters in the reaction process can be controlled by adjusting the applied voltage and current, thereby realizing automatic control. At the same time, the electrocatalytic oxidation process produces · OH and OCl ^- can degrade organic pollutants in wastewater into small molecular compounds or directly generate H ₂ O and CO ₂ by electrochemical combustion without secondary pollution.

(5) While the electrocatalytic oxidation process removes pollutants, the generated gas can also play the role of electrical flotation, even if part of the suspended particulate matter is removed by air flotation. At the same time, under appropriate treatment conditions, a part of ammonia nitrogen is directly oxidized at the anode to generate N ₂ and H ₂ O, and the other part of ammonia nitrogen is efficiently removed by the action of chlorine at a similar breakpoint. The denitrification effect of this method is obvious. Since macromolecular organic pollutants generally have chromaticity, the electrocatalytic oxidation method can destroy the structure of macromolecular pollutants and at the same time, the chromaticity of wastewater can be significantly reduced.

(6) The present invention determines the pretreatment process of first-level micro-electrolysis-primary coagulation-precipitation-advanced electrocatalytic oxidation-second-level micro-electrolysis-secondary coagulation-precipitation on the basis of small-scale test and pilot-scale test, and uses it successfully applied to engineering practice. The operation results show that the process route has significant pretreatment effect on high-concentration antibiotics (such as azithromycin) production wastewater, stable operation, economical and reasonable, and stable effluent quality. Broad application prospects.

Description of drawings:

Fig. 1 is a flow chart of the pretreatment of antibiotic production wastewater using the method of the present invention.

Fig. 2 is the CODcr value change curve diagram of the effluent of each section after applying the treatment process in Example 1.

3 is a graph showing the change of the NH ₃ -N value of the effluent from each section after applying the treatment process in Example 1.

Fig. 4 is the CODcr value change curve diagram of the effluent of each section after applying the treatment process in Example 2.

FIG. 5 is a graph showing the change of the NH ₃ -N value of the effluent from each section after applying the treatment process in Example 2. FIG.

Fig. 6 is the CODcr value change curve diagram of the effluent of each section after applying the treatment process in Example 3.

FIG. 7 is a graph showing the change of the NH ₃ -N value of the effluent from each section after applying the treatment process in Example 3. FIG.

FIG. 8 is a graph showing the change of CODcr value of the effluent from each section after applying the treatment process in Example 4. FIG.

FIG. 9 is a graph showing the change of the NH ₃ -N value of the effluent from each section after applying the treatment process in Example 4. FIG.

Detailed ways:

The present invention provides a specific embodiment to further illustrate the present invention below, but those skilled in the art should understand that the specific examples of the present invention do not limit the present invention in any way, and any equivalent replacements on the basis of the present invention fall into the present invention. within the scope of protection.

Embodiment 1: Azithromycin production wastewater pretreatment method:

Take the azithromycin production wastewater from a pharmaceutical company in Jiangsu for pilot-scale experiments. The experimental process is as follows:

(1) First-level micro-electrolysis: The azithromycin production wastewater is discharged from the production workshop and then enters the regulating tank. The pH of the wastewater is adjusted to 3.0-5.0 by adding H ₂ SO ₄ and then enters the first-level micro-electrolysis reactor. The primary cell reaction and redox reaction occur, and the wastewater is fully contacted and mixed with the structured packing under the action of aeration, so that the reaction can be carried out continuously and efficiently.

(2) Primary coagulation and precipitation: After micro-electrolysis treatment, most of the small molecular organic matter in the wastewater is removed, and at the same time, the filler has a certain decolorization effect on the wastewater. Due to the presence of a large amount of Fe ²⁺ in the wastewater due to the galvanic cell reaction, Fe ²⁺ will have an impact on the electrode of the subsequent advanced electrocatalytic oxidation. Therefore, the pH of the wastewater is adjusted to above 9.0 (including 9.0) by adding NaOH, and adding PAC and PAM To achieve the purpose of removing Fe ²⁺ , at the same time, in the process, the suspended particles in the wastewater are removed by flocculation and sedimentation, and finally the effect of mud-water separation is achieved.

(3) Advanced electrocatalytic oxidation: After the initial coagulation and precipitation, the supernatant liquid is adjusted to pH 3.0-5.0 by adding H ₂ SO ₄ and directly enters the electrocatalytic reaction generator. The constant current is adjusted to 15.9A, that is, the current density is 10mA/cm ² , and the electrode spacing is 25mm. Since the original wastewater contains a large amount of Cl ^- , a large amount of active chlorine is generated in the reaction, and the macromolecular organic matter is oxidized into small molecular organic matter, while removing a large amount of ammonia nitrogen and Further decolorization of wastewater.

(4) Two-stage micro-electrolysis: the organic matter in the wastewater after electrocatalytic oxidation has been further converted into small molecular organic matter or directly removed. After treatment, the effluent directly enters the secondary micro-electrolysis reactor, and the organic matter in the wastewater is further removed by the redox action of the primary battery. Aeration is also performed to make the wastewater and the filler more fully contact and react, and the treatment effect is improved.

(5) Secondary coagulation and sedimentation: The pH of the wastewater is adjusted to above 9.0 (including 9.0) by adding NaOH, and PAC and PAM are added to remove the suspended particles in the wastewater by flocculation and sedimentation, and finally achieve the effect of mud-water separation. The supernatant enters the subsequent biochemical treatment reactor.

COD and NH ₃ -N were detected by sampling the effluent of each treatment unit, and the results were as follows:

Embodiment 2: solvent waste water pretreatment method

The solvent wastewater from a pharmaceutical company in Jiangsu was used for pilot-scale experiments. The experimental process is as follows: (1) First-level micro-electrolysis: The solvent wastewater is discharged from the production workshop and then enters the regulating tank, and the pH of the wastewater is adjusted to 3.0-5.0 by adding H ₂ SO ₄ . into the primary microelectrolysis reactor. Under the action of aeration, the wastewater is fully contacted and mixed with the structured packing, so that the reaction can be carried out continuously and efficiently.

(2) Primary coagulation and sedimentation: The pH of the wastewater is adjusted to above 9.0 by adding NaOH, and PAC and PAM are added to remove the suspended particles in the wastewater by flocculation and sedimentation, and finally achieve the effect of mud-water separation.

(3) Advanced electrocatalytic oxidation: After the initial coagulation and precipitation, the supernatant liquid is adjusted to 3.0-5.0 by adding H ₂ SO ₄ and directly enters the electrocatalytic reaction generator. The constant current is adjusted to 15.9A, that is, the current density is 10mA/cm ² , and the electrode spacing is 25mm. Since the original wastewater contains a large amount of Cl ^- , a large amount of active chlorine is generated in the reaction to oxidize macromolecular organic matter into small molecular organic matter, while removing a large amount of ammonia nitrogen and making the The wastewater is further decolorized.

(4) Secondary micro-electrolysis: after electrocatalytic oxidation treatment, the effluent directly enters the secondary micro-electrolysis reactor, and the organic matter in the wastewater is further removed by the redox action of the primary battery, and aeration is also performed to make the wastewater and the filler more fully contact reaction, Improve wastewater treatment effect.

(5) Secondary coagulation and sedimentation: The pH of the wastewater is adjusted to above 9.0 by adding NaOH, and PAC and PAM are added to remove the suspended particles in the wastewater by flocculation and sedimentation, and finally achieve the effect of mud-water separation. After separation, the supernatant enters the subsequent biochemical treatment reactor.

COD and NH ₃ -N were detected by sampling the effluent of each treatment unit, and the results were as follows:

Embodiment 3: Azithromycin production wastewater pretreatment method

Take the azithromycin production wastewater from a pharmaceutical company in Liaoning for pilot-scale experiments. The experimental process is as follows:

(1) First-level micro-electrolysis: The azithromycin production wastewater is discharged from the production workshop and then enters the regulating tank. After adjusting the pH of the wastewater to 3 by adding H ₂ SO ₄ , it enters the first-level micro-electrolysis reactor, and the wastewater rapidly occurs in the micro-electrolysis reactor. Battery reaction and redox reaction, under the action of aeration, the wastewater is fully contacted and mixed with the structured packing, so that the reaction can be carried out continuously and efficiently.

(2) Primary coagulation and precipitation: After micro-electrolysis treatment, most of the small molecular organic matter in the wastewater is removed, and at the same time, the filler has a certain decolorization effect on the wastewater. Due to the presence of a large amount of Fe ²⁺ in the wastewater due to the galvanic cell reaction, Fe ²⁺ will affect the electrodes of subsequent advanced electrocatalytic oxidation. Therefore, the pH of the wastewater is adjusted to 10.0 by adding NaOH, and PAC and PAM are added to remove Fe ²⁺ For the purpose of flocculating Fe ²⁺ in the form of Fe(OH) ₂ with PAC and PAM to produce precipitation, the precipitation time is 30min; after micro-electrolysis and initial coagulation and precipitation, the small molecular organic pollutants in the wastewater are removed Rapid degradation, the COD value of the wastewater is reduced and the suspended particles in the wastewater are also removed; that is to say, in this process, the suspended particles in the wastewater are removed by flocculation and sedimentation, and finally the effect of mud-water separation is achieved.

(3) Advanced Electrocatalytic Oxidation: Advanced Electrocatalytic Oxidation: After the initial coagulation and precipitation, the supernatant liquid is adjusted to pH 5.0 by adding H ₂ SO ₄ and directly enters the electrocatalytic reaction generator. The electrode in the electrocatalytic oxidation reaction generator adopts a ruthenium-iridium electrode as an anode and a titanium electrode as a cathode. The electrodes are composed of 3 anodes and 2 cathodes, the distance between the electrodes is 25mm, the current density is 20mA/cm ² , and the reaction time is 4h; The original wastewater contains a large amount of Cl ^- , which makes the reaction generate a large amount of active chlorine, oxidizes macromolecular organic matter into small molecular organic matter, removes a large amount of ammonia nitrogen and further decolorizes the wastewater. The pollutants undergo electrochemical oxidation and electrochemical combustion on the surface of the electrode, part of which is converted into substances that are easily degraded by microorganisms, and the other part is oxidized into inorganic substances such as H ₂ O and CO ₂ . The pollutants are further oxidized, so that the polycyclic macromolecular organic pollutants undergo ring-opening phenomenon for subsequent treatment;

(4) Two-stage micro-electrolysis: The pH of the wastewater after the electrocatalytic oxidation reaction is adjusted to 3.0, and the organic matter in the wastewater after electrocatalytic oxidation has been further converted into small molecular organic matter or directly removed. After treatment, the effluent directly enters the secondary micro-electrolysis reactor. During the reaction, aeration is carried out to further remove the organic matter in the wastewater through the redox action of the primary battery. The same aeration is carried out to make the wastewater and the filler more fully contact and react, and the treatment effect is improved. The wastewater and the filler can be fully contacted, and the reaction is more sufficient; because most of the polycyclic aromatic macromolecular compounds in the wastewater are oxidized and ring-opened after the electrocatalytic oxidation reaction to form small molecular organic pollutants; refractory organic compounds and residual antibiotics or Break the double bond, or decompose the complex macromolecular structure into a linear small molecular structure; therefore, the secondary micro-electrolysis reaction is used to further degrade small molecular organic pollutants, so as to increase the B/C and meet the requirements of subsequent biochemical treatment;

(5) Secondary coagulation and precipitation: a large amount of Fe ²⁺ contained in the wastewater after the secondary micro-electrolysis treatment will affect the subsequent biochemical treatment and easily cause corrosion of the pipeline. Therefore, the pH of the effluent is adjusted to ≥ 9.0, that is, through Add NaOH to adjust the pH of the wastewater to 10, and add PAC and PAM to remove the suspended particles in the wastewater by flocculation and sedimentation, so that Fe ²⁺ generates Fe(OH) ₂ and flocculates with PAC and PAM to finally produce precipitation, The precipitation time was 1h. Finally, the effect of mud-water separation is achieved. The supernatant enters the subsequent biochemical treatment reactor.

COD and NH ₃ -N were detected by sampling the effluent of each treatment unit, and the results were as follows:

The COD of the waste water produced by antibiotics in the above (1) step is 40000 mg/L.

(1) The filling rate of the filler in the first-stage micro-electrolysis reactor in the step is 50%, and the reaction time is 5h.

The intermediate produced by the electrochemical reaction process is active chlorine produced by adding NaCl.

(4) In the step, the filling rate of the filler in the secondary micro-electrolysis reactor is 30%, and the reaction time is 5h.

(5) After the step, most of the suspended particles have been removed, the chromaticity of the wastewater is significantly reduced, and the COD of the wastewater reaches about 10,000 mg/L, which greatly reduces the pressure of the subsequent biochemical treatment and the increase in B/C is beneficial to the subsequent biochemical treatment.

Embodiment 4: solvent waste water pretreatment method

The solvent wastewater from a pharmaceutical company in Heilongjiang was used for pilot-scale experiment. The experimental process is as follows: (1) First-level micro-electrolysis: the azithromycin production wastewater is discharged from the production workshop and then enters the regulating tank, and the pH of the wastewater is adjusted to 5 by adding H ₂ SO ₄ . In the first-stage micro-electrolysis reactor, galvanic cell reaction and redox reaction occur rapidly in the waste water.

(2) Primary coagulation and precipitation: After micro-electrolysis treatment, most of the small molecular organic matter in the wastewater is removed, and at the same time, the filler has a certain decolorization effect on the wastewater. Due to the presence of a large amount of Fe ²⁺ in the wastewater due to the galvanic cell reaction, Fe ²⁺ will affect the electrode of subsequent advanced electrocatalytic oxidation. Therefore, the pH of the wastewater is adjusted to 11.0 by adding NaOH, and PAC and PAM are added to remove Fe ²⁺ For the purpose of flocculating Fe ²⁺ in the form of Fe(OH) ₂ with PAC and PAM to produce precipitation, the precipitation time is 60min; after micro-electrolysis and initial coagulation and precipitation, the small molecular organic pollutants in the wastewater are removed Rapid degradation, the COD value of the wastewater is reduced and the suspended particles in the wastewater are also removed; that is to say, in this process, the suspended particles in the wastewater are removed by flocculation and sedimentation, and finally the effect of mud-water separation is achieved.

(3) Advanced Electrocatalytic Oxidation: Advanced Electrocatalytic Oxidation: After the initial coagulation and precipitation, the supernatant liquid is adjusted to pH 3.0 by adding H ₂ SO ₄ and directly enters the electrocatalytic reaction generator. The electrode in the electrocatalytic oxidation reaction generator adopts a ruthenium-iridium electrode as an anode and a titanium electrode as a cathode. The electrodes are composed of 3 anodes and 2 cathodes, the distance between the electrodes is 25mm, the current density is 20mA/cm ² , and the reaction time is 4h; The original wastewater contains a large amount of Cl ^- , which makes the reaction generate a large amount of active chlorine, oxidizes macromolecular organic matter into small molecular organic matter, removes a large amount of ammonia nitrogen and further decolorizes the wastewater. The pollutants undergo electrochemical oxidation and electrochemical combustion on the surface of the electrode, part of which is converted into substances that are easily degraded by microorganisms, and the other part is oxidized into inorganic substances such as H ₂ O and CO ₂ . The pollutants are further oxidized, so that the polycyclic macromolecular organic pollutants undergo ring-opening phenomenon for subsequent treatment;

(4) Secondary micro-electrolysis: The pH of the wastewater after electrocatalytic oxidation is adjusted to 5.0, and the organic matter in the wastewater after electrocatalytic oxidation has been further converted into small molecular organic matter or directly removed. After treatment, the effluent directly enters the secondary micro-electrolysis reactor. During the reaction, aeration is carried out to further remove the organic matter in the wastewater through the redox action of the primary battery. The same aeration is carried out to make the wastewater and the filler more fully contact and react, and the treatment effect is improved. The wastewater and the filler can be fully contacted, and the reaction is more sufficient; because most of the polycyclic aromatic macromolecular compounds in the wastewater are oxidized and ring-opened after the electrocatalytic oxidation reaction to form small molecular organic pollutants; refractory organic compounds and residual antibiotics or Break the double bond, or decompose the complex macromolecular structure into a linear small molecular structure; therefore, the secondary micro-electrolysis reaction is used to further degrade small molecular organic pollutants, so as to increase the B/C and meet the requirements of subsequent biochemical treatment;

(5) Secondary coagulation and precipitation: a large amount of Fe ²⁺ contained in the wastewater after the secondary micro-electrolysis treatment will affect the subsequent biochemical treatment and easily cause corrosion of the pipeline. Therefore, the pH of the effluent is adjusted to ≥ 9.0, that is, through Add NaOH to adjust the pH of the wastewater to 11, and add PAC and PAM to remove the suspended particles in the wastewater by flocculation and sedimentation, so that Fe ²⁺ generates Fe(OH) ₂ and flocculates with PAC and PAM to finally produce precipitation, The precipitation time was 1h. Finally, the effect of mud-water separation is achieved. The supernatant enters the subsequent biochemical treatment reactor.

COD and NH ₃ -N were detected by sampling the effluent of each treatment unit, and the results were as follows:

The COD of the waste water produced by antibiotics in the above (1) step is 50000 mg/L.

(1) The filling rate of the filler in the first-stage micro-electrolysis reactor in the step is 30%, and the reaction time is 5h.

The intermediate produced by the electrochemical reaction process is active chlorine produced by adding NaCl.

(4) In the step, the filling rate of the filler in the secondary micro-electrolysis reactor is 50%, and the reaction time is 5h.

(5) After the step, most of the suspended particles have been removed, the chromaticity of the wastewater is significantly reduced, and the COD of the wastewater reaches about 10,000 mg/L, which greatly reduces the pressure of the subsequent biochemical treatment and the increase in B/C is beneficial to the subsequent biochemical treatment.

Claims (7)

1. the pretreatment method of antibiotic production wastewater, is characterized in that: the method comprises the following steps: The method includes the following steps: The specific operation steps and specific operation techniques are as follows: (1) First-level micro-electrolysis: After the antibiotic production wastewater enters the regulating tank, the wastewater is temporarily stored and homogenized in the regulating tank, and the pH is adjusted to 3.0~5.0, and then enters the first-level micro-electrolysis reactor for redox and primary batteries. Reaction, aeration is carried out during the reaction process, so that the waste water and the filler can be fully contacted, and the reaction is more sufficient; (2) Primary coagulation and precipitation: After the first-level micro-electrolysis reaction of antibiotic production wastewater, the effluent contains a large amount of Fe ²⁺ , which needs to be removed, otherwise it will affect the advanced electrocatalytic oxidation reaction in the next stage, and adjust the pH of the effluent. When it reaches ≥9.0, enter the vertical flow primary coagulation sedimentation tank, add a certain amount of PAC and PAM to cause Fe ²⁺ to flocculate with PAC and PAM in the form of Fe(OH) ₂ to produce precipitation, and the precipitation time is 30~60min; After micro-electrolysis and initial coagulation and precipitation, the small molecular organic pollutants in the wastewater are rapidly degraded, the COD value of the wastewater is reduced, and the suspended particles in the wastewater are also removed; (3) Advanced electrocatalytic oxidation: adjust the pH of the effluent from the primary coagulation sedimentation tank to 3.0~5.0, and directly enter the electrocatalytic reaction generator. The electrodes in the electrocatalytic oxidation reaction generator use ruthenium-iridium electrodes as anodes and titanium electrodes as cathodes. The electrode consists of 3 anodes and 2 cathodes, the distance between electrodes is 25mm, the current density is 20mA/cm ² , and the reaction time is 4h; the pollutants are electrochemically oxidized and burned on the surface of the electrodes, and part of the pollutants are converted into easily accessible microorganisms. The other part of the degraded substances is oxidized into H ₂ O and CO ₂ inorganic substances. At the same time, the intermediates generated by the electrochemical reaction process are used to further oxidize the pollutants, so that the polycyclic macromolecular organic pollutants undergo ring-opening phenomenon, so that for subsequent processing; (4) Secondary micro-electrolysis: adjust the pH of the wastewater after the electrocatalytic oxidation reaction to 3.0~5.0, enter the secondary micro-electrolysis reactor, and conduct aeration during the reaction process, so that the wastewater and the filler can be fully contacted, and the reaction is more sufficient; After electrocatalytic oxidation reaction, most of the polycyclic aromatic macromolecular compounds in wastewater are oxidized and ring-opened to form small organic pollutants; refractory organic compounds and residual antibiotics or broken double bonds, or decomposed into complex macromolecular structures Straight-chain small molecule structure; therefore, the small molecule organic pollutants are further degraded through the secondary micro-electrolysis reaction, so that the B/C is increased, and the subsequent biochemical treatment requirements are met; (5) Secondary coagulation and precipitation: a large amount of Fe ²⁺ contained in the wastewater after the secondary micro-electrolysis treatment will affect the subsequent biochemical treatment and easily cause the corrosion of the pipeline. Therefore, adjust the pH of the effluent ≥ 9.0 to make the Fe ²⁺ generates Fe(OH) ₂ and flocculates with PAC and PAM to finally produce precipitation, and the precipitation time is 1h; (1) The COD of wastewater produced by antibiotics in the step is 40000-50000 mg/L; The antibiotic is azithromycin. 2. the pretreatment method of antibiotic production waste water according to claim 1, is characterized in that: a kind of azithromycin production waste water is the mixed effluent of each production process waste water. 3. the pretreatment method of antibiotic production wastewater according to claim 1, is characterized in that: the device that implements above-mentioned treatment method is composed of one-level micro-electrolysis reactor, primary coagulation sedimentation tank, electrocatalytic oxidation reaction generator, secondary It consists of a micro-electrolysis reactor and a secondary coagulation sedimentation tank. 4. The pretreatment method of antibiotic production wastewater according to claim 1, characterized in that: (1) the filling rate of the filler in the first-level micro-electrolysis reactor in the step is 30% to 50%, and the reaction time is 5h. 5. The pretreatment method of antibiotic production wastewater according to claim 1, wherein the intermediate produced by the electrochemical reaction process is the active chlorine produced by adding NaCl. 6. The pretreatment method of antibiotic production wastewater according to claim 1, characterized in that: in step (4), the filling rate of the filler in the secondary micro-electrolysis reactor is 30% to 50%, and the reaction time is 5h. 7. The pretreatment method of antibiotic production wastewater according to claim 1, characterized in that: after step (5), most of the suspended particulate matter has been removed, the chromaticity of the wastewater is significantly reduced, and the COD of the wastewater reaches 10,000 mg/L, which greatly reduces the chromaticity of the wastewater. The pressure of subsequent biochemical treatment is reduced and the increase in B/C is beneficial to subsequent biochemical treatment.

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