Apparatus for degrading mesotrione pesticide by using double-chamber bioelectrochemical system and degradation method thereof

Abstract

The application relates to a device for degrading a methasulfocarb pesticide by using a double-chamber bioelectrochemical system and a degradation method thereof, and relates to the field of degradation of methasulfocarb pesticide wastewater.The device comprises an anode system and a cathode system, and the methasulfocarb pollutants are located in the cathode system.The method is to use a bioelectrochemical reduction technology in the cathode system, to strengthen the methasulfocarb pesticide wastewater treatment under the action of a constant voltage through the synergistic effect of electrophilic microorganisms of a biological cathode and an electrode.The application has the characteristics of simple operation, low cost, low energy consumption and high degradation efficiency.The application is suitable for repairing soil or water pollution containing the methasulfocarb pesticide.

Description

Technical Field

[0001] This invention relates to the field of degradation of mesotrione pesticide wastewater, and specifically to a method for degrading the pesticide mesotrione using a two-chamber bioelectrochemical system. Background Technology

[0002] With population growth, human demand for food is increasing daily. Therefore, pesticides have become an indispensable part of agricultural production to mitigate the impact of weeds on crops and ensure crop yield and quality. While pesticides ensure high yields, a small portion is absorbed by plants during application, and long-term, high-volume application leads to significant pesticide residues in the soil. Furthermore, a large portion of these residues enters the aquatic environment through farmland runoff or irrigation drainage, posing a threat to ecosystems and human health. Mesotrione is stable under light but exhibits high water solubility, high fluidity, and a long half-life. Its use can pollute agricultural soils and aquatic environments, posing a significant challenge to agricultural production and ecological security. Therefore, finding a green and efficient method to accelerate the removal of mesotrione residues from the environment is crucial. Summary of the Invention

[0003] In order to solve the technical problem of the ecological harm caused by mesotrione residues to soil and water bodies, the present invention provides a device and method for degrading mesotrione pesticides using a two-chamber bioelectrochemical system.

[0004] A device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system is disclosed. The device includes a bioanode, a reference electrode, a cation exchange membrane, a biocathode, a reactor, a DC power supply, and a resistor. The cation exchange membrane divides the reactor into an anode chamber and a cathode chamber. Inlets are arranged at the top of both the anode and cathode chambers, and outlets are arranged on the front walls of both chambers. The reference electrode is located in the anode chamber, which contains glucose and electrolyte solutions. The cathode chamber contains glucose, mesotrione, and electrolyte solutions. The bioanode is located in the anode chamber, and the biocathode is located in the cathode chamber. Both the bioanode and biocathode are made of carbon fiber brushes. The bioanode is connected to the positive terminal of the DC power supply via a wire, and the biocathode is connected to the negative terminal of the DC power supply via a wire, with a resistor connected in series.

[0005] The degradation method of the device using a two-chamber bioelectrochemical system to degrade mesotrione pesticide is carried out according to the following steps:

[0006] 1. Take a device that uses a dual-chamber bioelectrochemical system to degrade mesotrione pesticide. Inject glucose and electrolyte solution through the inlet of the anode chamber and inject glucose, mesotrione and electrolyte solution through the inlet of the cathode chamber. Then, inoculate sludge into the anode chamber and the cathode chamber.

[0007] II. The device described in step one, which utilizes a dual-chamber bioelectrochemical system to degrade mesotrione pesticide, is operated in a sequential batch manner, thereby directionally acclimating electroactive microorganisms on the bioanode and biocathode to form a stable biofilm.

[0008] Third, after the device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system is stably operated through step two, the voltage of the DC power supply and the concentration of glucose in the cathode chamber are adjusted to degrade mesotrione.

[0009] The method of operating the device in the sequential batch manner described in step two is to simultaneously acclimate the anode biofilm and the cathode biofilm in a gradient manner, for a total of 3 acclimatization cycles, each acclimatization cycle being 6 days, with a voltage of 0.50V.

[0010] The device of this invention consists of an anode system and a cathode system, with the mesotrione contaminant located in the cathode system. The method of this invention utilizes bioelectrochemical reduction technology in the cathode system, leveraging the synergistic effect of electrode-loving microorganisms in the biocathode and the electrodes to enhance the treatment of mesotrione pesticide wastewater under constant voltage. It is suitable for the remediation of soil or water pollution containing mesotrione pesticides.

[0011] This invention couples biotechnology and electrochemical technology. Under weak electrical stimulation, electrodes (carbon fiber brushes) are loaded with a large number of functional microorganisms to achieve deep detoxification and mineralization of recalcitrant pollutants. This invention utilizes the influence of applied voltage and co-matrix (glucose) concentration on the degradation performance of mesotrione to improve its degradation efficiency, thereby achieving the mineralization of pollutants.

[0012] Bioelectrochemical systems (BES) couple electrochemical technology to a biotechnology-based treatment process. Under weak electrical stimulation, a large number of electroactive microorganisms are attached to the anode and cathode, which can reduce the overpotential of the electrochemical reaction. Microorganisms at the anode undergo oxidation reactions, consuming simple substrates (such as glucose, sodium acetate, and crop straw) or complex substrates (such as pesticides and phenolic compounds) to generate more electrons and protons. In a closed loop, the cathode receives electrons transferred from the anode and undergoes a reduction reaction, achieving the removal of recalcitrant pollutants or converting them into easily degradable substances. Therefore, the treatment efficiency of bioelectrochemical systems is superior to traditional biological and electrochemical treatment technologies. Due to its advantages such as high degradation efficiency, good versatility, short cycle time, economic feasibility, and no secondary pollution, this system has great potential for removing recalcitrant organic pollutants.

[0013] Beneficial effects of this invention:

[0014] This invention combines electrochemical technology with biological treatment processes, and the reactor employs a simple two-chamber reactor assembly. It offers the following advantages: ① The anode and cathode chambers of the two-chamber reactor are separated by a cation exchange membrane, which avoids the stressing effect of recalcitrant pollutants in the cathode chamber on the electroactive microorganisms in the anode chamber. Therefore, the electroactive microorganisms in the anode chamber can consume simple organic matter to generate electricity and continuously transfer electrons and protons to the cathode. The cathode receives the electrons and protons transferred from the anode, achieving the reductive detoxification treatment of mesotrione and improving the biodegradability of recalcitrant wastewater. ② The two-chamber reactor configuration allows microorganisms in the anode chamber to focus on electricity generation, while those in the cathode chamber focus on degradation. This clear division of labor facilitates the stable operation of the bioelectrochemical system, achieving the goal of efficient degradation of mesotrione, and avoiding the complexity of the anode chamber performing multiple functions.

[0015] The electrode material used in the dual-chamber reactor of this invention is a carbon fiber brush, which has a high specific surface area and good biocompatibility, providing more attachment sites to promote the attachment and growth of electroactive and functional microorganisms on the carbon fiber surface in both the anode and cathode, forming a stable biofilm. Furthermore, the carbon fiber brush has excellent electrical conductivity, rapidly transferring electrons generated by electroactive microorganisms in the anode to the cathode, where they can be utilized by electrodephilic microorganisms or other functional microorganisms, thereby accelerating the removal of mesotrione. Compared with electrode materials such as carbon cloth, carbon fiber brushes are lower in cost and have significant advantages in practical applications.

[0016] This invention also features simple operation, low energy consumption, and strong practicality. It is also conducive to the construction of large dual-chamber reactors to achieve deep removal of recalcitrant pollutants in farmland runoff or irrigation drainage, thereby achieving mineralization.

[0017] This invention is used to degrade mesotrione pesticide wastewater. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system as described in Example 1;

[0019] Figure 2 Example 1 shows the degradation performance of mesotrione;

[0020] Figure 3 The graph shows the degradation performance of mesotrione in Example 2. Detailed Implementation

[0021] Specific Implementation Method 1: This implementation method discloses a device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system. The device includes a bioanode 1, a reference electrode 2, a cation exchange membrane 3, a biocathode 4, a reactor 5, a DC power supply, and a resistor. The cation exchange membrane 3 divides the reactor 5 into an anode chamber and a cathode chamber. Inlets are arranged at the top of both the anode and cathode chambers, and outlets are arranged on the front walls of both chambers. The reference electrode 2 is located in the anode chamber, which contains glucose and electrolyte solutions. The cathode chamber contains glucose, mesotrione, and electrolyte solutions. The bioanode 1 is located in the anode chamber, and the biocathode 4 is located in the cathode chamber. Both the bioanode 1 and the biocathode 4 are made of carbon fiber brushes. The bioanode is connected to the positive terminal of the DC power supply via a wire, and the biocathode is connected to the negative terminal of the DC power supply via a wire, with a resistor connected in series.

[0022] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the resistor is 20Ω. Everything else is the same as in Specific Implementation Method One.

[0023] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the reference electrode 2 is an Hg / Hg2Cl2 electrode. Everything else is the same as in Specific Implementation Method 1 or 2.

[0024] Specific Implementation Method Four: This implementation method describes a degradation method for mesotrione pesticide using a dual-chamber bioelectrochemical system, specifically carried out according to the following steps:

[0025] 1. Take a device that uses a dual-chamber bioelectrochemical system to degrade mesotrione pesticide. Inject glucose and electrolyte solution through the inlet of the anode chamber and inject glucose, mesotrione and electrolyte solution through the inlet of the cathode chamber. Then, inoculate sludge into the anode chamber and the cathode chamber.

[0026] II. The device described in step one, which utilizes a dual-chamber bioelectrochemical system to degrade mesotrione pesticide, is operated in a sequential batch manner, in which electroactive microorganisms are directionally domesticated on the bioanode 1 and biocathode 4 to form a stable biofilm.

[0027] Third, after the device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system is stably operated through step two, the voltage of the DC power supply and the concentration of glucose in the cathode chamber are adjusted to degrade mesotrione.

[0028] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that: the electrolyte solution in the cathode and anode chambers in step one is a phosphate solution, wherein the concentration of disodium hydrogen phosphate is 11.55 g / L. -1 The concentration of sodium dihydrogen phosphate is 2.77 g / L. -1 Everything else is the same as in Specific Implementation Method Four.

[0029] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods Four or Five in that: the concentration of glucose in the anode chamber in step one is 1000 mg / L. -1 The concentration of glucose in the cathode chamber is 250 mg / L. -1 The rest is the same as in specific implementation methods four or five.

[0030] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods Four to Six in that the sludge used for inoculation in step one is sludge from the secondary sedimentation tank of a wastewater treatment plant. Everything else is the same as in Specific Implementation Methods Four to Six.

[0031] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods Four to Seven in that the method of operating the device in the sequential batch manner described in step two specifically involves gradient synchronous acclimatization of the anode and cathode biofilms, for a total of three acclimatization cycles, each acclimatization cycle being 6 days, with a voltage of 0.50V. Everything else is the same as in Specific Implementation Methods Four to Seven.

[0032] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods Four to Eight in that the voltage adjustment range of the DC power supply in step three is 0–0.75V. Everything else is the same as in Specific Implementation Methods Four to Eight.

[0033] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Four to Nine in that: in step three, the concentration of glucose in the cathode chamber is adjusted to 0–750 mg / L. -1 The rest is the same as in any of the specific implementation methods four to nine.

[0034] The scope of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.

[0035] Example 1:

[0036] This embodiment discloses a device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system. The device includes a bioanode 1, a reference electrode 2, a cation exchange membrane 3, a biocathode 4, a reactor 5, a DC power supply, and a resistor. The cation exchange membrane 3 divides the reactor 5 into an anode chamber and a cathode chamber. Inlets are arranged at the top of both the anode and cathode chambers, and outlets are arranged on the front walls of both chambers. The reference electrode 2 is located in the anode chamber, which contains a glucose solution. The cathode chamber contains a mixed solution of glucose and mesotrione. The bioanode 1 is located in the anode chamber, and the biocathode 4 is located in the cathode chamber. Both the bioanode 1 and the biocathode 4 are made of carbon fiber brushes. The bioanode is connected to the positive terminal of the DC power supply via a wire, and the biocathode is connected to the negative terminal of the DC power supply via a wire, with a resistor connected in series.

[0037] The resistor is 20Ω.

[0038] The reference electrode 2 is an Hg / Hg2Cl2 electrode.

[0039] The degradation method of the device using a two-chamber bioelectrochemical system to degrade mesotrione pesticide is carried out according to the following steps:

[0040] I. A device for degrading mesotrione pesticide using a two-chamber bioelectrochemical system is used. Glucose and electrolyte solutions are injected through the inlet of the anode chamber. The concentration of glucose is 1000 mg / L. -1 Glucose, mesotrione, and electrolyte solution are injected through the cathode chamber inlet, wherein the concentration of mesotrione is 5 mg / L. -1 The glucose concentration is 250 mg / L. -1 Both the anode and cathode chambers contain 62 mL of phosphate solution, with a disodium hydrogen phosphate concentration of 11.55 g / L. -1 The concentration of sodium dihydrogen phosphate is 2.77 g / L. -1 Then, 20 mL of sludge from the secondary sedimentation tank of a wastewater treatment plant was inoculated into both the anode and cathode chambers.

[0041] II. Under room temperature conditions, the device described in step one, which utilizes a dual-chamber bioelectrochemical system to degrade mesotrione pesticide, is operated in a sequential batch manner, and electroactive microorganisms are directionally domesticated on bioanode 1 and biocathode 4 to form a stable biofilm.

[0042] The specific method for operating the device in the sequential batch manner is as follows: the anode biofilm and cathode biofilm are simultaneously acclimatized in a gradient manner for a total of 3 cycles, each acclimatization cycle is 6 days, and the voltage is 0.50V;

[0043] Third, after the device for degrading mesotrione pesticide using a dual-chamber bioelectrochemical system is stably operated through step two, the voltage of the DC power supply and the concentration of glucose in the cathode chamber are adjusted to degrade mesotrione.

[0044] Step 3: Adjust the glucose concentration in the cathode chamber to 250 mg / L. -1 The device was used to degrade mesotrione. Parallel experiments were conducted with DC power supply voltages of 0V, 0.25V, 0.35V, 0.50V, and 0.75V, respectively, and each experiment lasted for 24 hours.

[0045] The degradation performance of mesotrione in this embodiment is shown in the figure below. Figure 2 As shown.

[0046] Depend on Figure 2It is evident that different applied voltages significantly affect the removal efficiency of mesotrione. The results show that the removal efficiency of mesotrione gradually increases with the applied voltage from 0V to 0.75V. When the applied voltages are 0V, 0.25V, 0.35V, 0.50V, and 0.75V, the removal efficiencies of mesotrione are 80.81±2.92%, 98.10±0.46%, 99.91±0.07%, 99.76±0.41%, and 99.85±0.13%, respectively. This indicates that the bioelectrochemical system can achieve a good degradation effect on mesotrione. When the applied voltage increases to 0.75V, the removal efficiency of mesotrione reaches its maximum, increasing by 20% compared to 0V, indicating that a higher applied voltage can enhance the removal of mesotrione. This may be because a suitable weak electrical environment can effectively stimulate microorganisms to enhance their electroactivity, promote electron transfer, and after applying an external voltage, provide effective electrons for the cathodic reduction reaction and accelerate electron transfer efficiency, ultimately significantly improving the degradation of the target pollutants.

[0047] Example 2:

[0048] The difference between this embodiment and Embodiment 1 is that in step three, the DC power supply voltage is adjusted to 0.5V, the device is run to degrade mesotrione, and the glucose concentration in the cathode chamber is adjusted to 0 mg / L. -1 250mg L -1 500mg / L -1 750mg L -1 Parallel experiments were conducted, each lasting 24 hours.

[0049] The degradation performance of mesotrione in this embodiment is shown in the figure below. Figure 3 As shown.

[0050] Depend on Figure 3 It can be seen that as the glucose concentration in the BES catholyte increases from 0 to 750 mg / L... -1 The removal efficiency of mesotrione at the cathode showed a gradual upward trend, and reached approximately 100% after 24 hours. This indicates that the bioelectrochemical system can effectively remove mesotrione and enhance its reduction and detoxification. Furthermore, the efficient removal of mesotrione requires electrons, partly from electrons transferred from electroactive bacteria at the anode to the cathode, and partly from electrons produced by functional microorganisms metabolizing glucose at the cathode. A higher glucose concentration can provide sufficient electrons for the reduction reaction of mesotrione, accelerating its removal. Therefore, a glucose concentration of 750 mg / L was selected. -1 .

[0051] In summary, in the bipolar chamber bioelectrochemical system, fermenting bacteria in the anode chamber can decompose glucose into small-molecule organic acids such as acetic acid and propionic acid. The electrons and carbon sources produced during fermentation can be utilized by electroactive bacteria, promoting electron transfer. Due to the synergistic effect between electroactive and fermenting bacteria, a large number of electrons accumulate in the anode, continuously transferring electrons needed for the reduction reaction (degradation of mesotrione) to the cathode. Functional microorganisms in the cathode chamber can not only utilize electrons transferred from the anode for metabolic activities but also rely on their own electroactive bacteria to enhance electron transfer, accelerating the overall metabolic activity of the cathode microorganisms and thus efficiently removing mesotrione. At the cathode, mesotrione mainly undergoes ketone group cleavage and nitro group reduction, converting a portion into easily degradable or low-toxicity intermediates and the remaining portion completely into CO2 and H2O, ultimately achieving the detoxification and mineralization of mesotrione. Therefore, the synergy of multiple functional microorganisms is a key factor in maintaining the efficient degradation of mesotrione. This experiment can treat wastewater containing recalcitrant pesticides, and features high removal efficiency, simple operation, and good stability, providing a theoretical basis and technical foundation for the efficient treatment of pesticide residues in farmland runoff or irrigation drainage.

Claims

1. A degradation method of a device for degrading the pesticide of mesotrione by using a dual-chambered bioelectrochemical system, characterized by The method is specifically performed according to the following steps: I. A device for degrading mesotrione pesticide by using a double-chamber bioelectrochemical system is taken, glucose and electrolyte solution are injected into the anode chamber through the water inlet, glucose, mesotrione and electrolyte solution are injected into the cathode chamber through the water inlet, and then sludge is inoculated into the anode chamber and the cathode chamber; II. The device for degrading mesotrione pesticide by using a double-chamber bioelectrochemical system described in step I is operated in a sequencing batch mode, and electrically active microorganisms are directionally domesticated on the biological anode (1) and the biological cathode (4) to form stable biofilms; III. After the device for degrading mesotrione pesticide by using a double-chamber bioelectrochemical system is stably operated in step II, the voltage of the direct current power supply and the concentration of glucose in the cathode chamber are adjusted to degrade mesotrione; The device for degrading mesotrione pesticide by using a double-chamber bioelectrochemical system comprises a biological anode (1), a reference electrode (2), a cation exchange membrane (3), a biological cathode (4), a reactor (5), a direct current power supply and a resistor. The cation exchange membrane (3) divides the reactor (5) into an anode chamber and a cathode chamber. The top of the anode chamber and the top of the cathode chamber are both arranged with water inlets, and the front wall of the anode chamber and the front wall of the cathode chamber are both arranged with water outlets. The reference electrode (2) is arranged in the anode chamber. The anode chamber is filled with glucose and electrolyte solution, and the cathode chamber is filled with glucose, mesotrione and electrolyte solution. The biological anode (1) is located in the anode chamber, and the biological cathode (4) is located in the cathode chamber. The material of the biological anode (1) and the material of the biological cathode (4) are both carbon fiber brushes. The biological anode is connected with the positive electrode of the direct current power supply through a wire, and the biological cathode is connected with the negative electrode of the direct current power supply through a wire, and the wire is connected with the resistor in series. Step one glucose concentration in anode compartment was 1000 mg L -1 Step one glucose concentration in anode compartment was 1000 mg L -1 ; The method for operating the device in a sequencing batch mode in step II is specifically a gradient synchronous domestication of anode biofilm and cathode biofilm, and the domestication is performed for 3 cycles. Each domestication cycle is 6 days, and the voltage is 0.50 V. Step three adjust the concentration of glucose in the cathode chamber to 0 mg L -1 .

2. The degradation method of the device for degrading mesotrione pesticide by using a dual-chamber bioelectrochemical system according to claim 1, characterized in that The resistor is 20Ω.

3. The degradation method of the device for degrading mesotrione pesticide by using a dual-chamber bioelectrochemical system according to claim 1, characterized in that The reference electrode (2) is a Hg / Hg2Cl2 electrode.

4. The method according to claim 1, wherein the method is characterized by The electrolyte solution in the cathode and anode compartments in step one is a phosphate solution with a concentration of 11.55 g L of disodium hydrogen phosphate -1 and 2.77 g L of sodium dihydrogen phosphate -1 .

5. The method according to claim 1, wherein the method is characterized by The sludge inoculated in step I is sludge from the secondary sedimentation tank of a sewage treatment plant.

6. The method according to claim 1, wherein the method is characterized by The voltage adjustment range of the direct current power supply in step III is 0~0.75 V.

Images