Method for degrading 6ppd-q by chlorella combined with carbonized molybdenum nanomaterial

Abstract

The application discloses a method for degrading 6PPD-Q by combining Chlorella with molybdenum carbide nanomaterials, inoculates Chlorella seedlings into an algal culture medium, and cultures under constant temperature conditions to obtain Chlorella suspension, mixes the Chlorella suspension with Mo2C MXene suspension to obtain a mixed solution containing Chlorella and Mo2C MXene, adds the mixed solution into a polluted water body containing 6PPD-Q to form a reaction system, and reacts under conditions suitable for Chlorella growth to degrade 6PPD-Q in the polluted water body. The application combines Chlorella with molybdenum carbide nanomaterials to construct a synergistic degradation system, fully utilizes the biological metabolism and adsorption capacity of microalgae and the catalytic activity of Mo2C MXene, improves the degradation efficiency of 6PPD-Q, and at the same time avoids the toxicity risk and cost burden existing in traditional treatment methods.

Description

Technical Field

[0001] This invention relates to the field of green and environmental protection technology, specifically to a method for degrading 6PPD-Q using Chlorella combined with molybdenum carbide nanomaterials. Background Technology

[0002] 6PPD-Q (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) is a widely used rubber antioxidant, primarily applied in rubber products such as tires, seals, and hoses. It effectively slows down the aging process of rubber under the influence of oxygen, ozone, and heat. Due to its excellent anti-aging properties, 6PPD-Q is used extensively in the global tire manufacturing industry. However, this compound is extremely difficult to degrade in the environment, exhibiting significant environmental persistence, bioaccumulation, and potential toxicity risks, which has attracted widespread attention from the environmental science community in recent years.

[0003] Studies have shown that 6PPD-Q can be washed into urban road runoff systems by rainwater during tire use, eventually flowing into surface water bodies and becoming a new type of water pollutant. Especially during heavy rains, 6PPD-Q residues and their oxidation products on road surfaces can rapidly enter nearby rivers or lakes via surface runoff. Reports have shown that 6PPD-quinone, an oxidation metabolite of 6PPD, is a major cause of acute mortality in some fish species (such as American salmon), exhibiting acute toxicity far exceeding that of the parent substance 6PPD, posing a serious ecological safety hazard. Therefore, developing efficient, green, and sustainable 6PPD-Q removal technologies has become an important direction in environmental research.

[0004] Current methods for treating 6PPD-Q mainly include physical adsorption, photocatalytic degradation, and microbial degradation. While each has its advantages, single technologies often suffer from low degradation efficiency, demanding reaction conditions, or high costs. Therefore, constructing a synergistic degradation system to achieve efficient removal of 6PPD-Q has become a research hotspot. Summary of the Invention

[0005] This application provides a novel method for the synergistic degradation of the rubber additive 6PPD-Q using Chlorella vulgaris in conjunction with molybdenum carbide nanomaterials (Mo2CMXene). This method aims to address the problems of low degradation efficiency, high cost, easy secondary pollution, and poor system stability in existing technologies. By constructing a microalgae-nanomaterial composite system, this application achieves efficient, green, and sustainable degradation of 6PPD-Q in water, providing a new approach and technical pathway for the treatment of this emerging organic pollutant in the environment.

[0006] In recent years, microalgae technology has become a new direction in pollutant treatment research due to its green, efficient, and sustainable characteristics. Chlorella vulgaris, a typical single-celled green algae, has a short growth cycle and strong adaptability, and can degrade organic pollutants to some extent through its metabolic products. At the same time, Chlorella can also adsorb heavy metals and organic toxins in the environment through extracellular polymers and surface functional groups, demonstrating good potential for environmental remediation.

[0007] Molybdenum carbide nanomaterials (Mo2C MXene) are a class of transition metal carbides with catalytic properties similar to noble metals, showing promising applications in electrocatalysis, water splitting, and wastewater treatment. Their nanostructures feature a large specific surface area and abundant active sites, enabling them to promote the conversion of recalcitrant organic pollutants through catalytic oxidation and other mechanisms. Studies have shown that Mo2C MXene can participate in electron transfer processes, enhancing carrier separation efficiency in photocatalytic systems.

[0008] This application proposes a synergistic degradation system combining Chlorella and molybdenum carbide nanomaterials. This system fully leverages the bio-metabolic and adsorption capabilities of microalgae and the catalytic activity of Mo2C MXene to enhance the degradation efficiency of 6PPD-Q, while avoiding the toxicity risks and cost burdens associated with traditional treatment methods. This novel combined strategy provides a new technological approach and application prospect for the green remediation of emerging pollutants, especially organic pollutants from rubber additives.

[0009] This application provides an application of Mo2C MXene in enhancing the degradation of 6PPD-Q by Chlorella.

[0010] This application also provides a method for enhancing the degradation of 6PPD-Q by Chlorella using molybdenum carbide nanomaterials, comprising:

[0011] The molybdenum carbide nanomaterial Mo2C MXene was added to polluted water containing both Chlorella and 6PPD-Q; or the molybdenum carbide nanomaterial Mo2C MXene and Chlorella were added synchronously or asynchronously to polluted water containing 6PPD-Q; and the 6PPD-Q was degraded under natural light and temperature.

[0012] Optionally, the dosage of the molybdenum carbide nanomaterial Mo2C MXene is 50~300 μg / L; more preferably 200~300 μg / L, and even more preferably 250 μg / L.

[0013] This application also provides a method for degrading 6PPD-Q using Chlorella combined with molybdenum carbide nanomaterials, comprising:

[0014] Chlorella strains were inoculated into an algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension. The Chlorella suspension was mixed with a Mo2C MXene suspension to obtain a mixture containing both Chlorella and Mo2C MXene. The mixture was added to polluted water containing 6PPD-Q to form a reaction system, and reacted under suitable conditions for Chlorella growth to degrade 6PPD-Q in the polluted water.

[0015] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0016] Optionally, the particle size of the Mo2C MXene ranges from 10 nm to 100 nm. The Mo2C MXene can be prepared by chemical reduction or physical vapor deposition, or it can be purchased directly from the market.

[0017] Optionally, the initial concentration of Chlorella in the reaction system is 1~5×10⁻⁶. 6 The concentration of Mo2C MXene in the reaction system was 50–300 μg / L; the initial concentration of 6PPD-Q in the reaction system was 25–100 μg / L. At these concentration ratios, better degradation effects were observed.

[0018] More preferably, the concentration of Mo2C MXene in the reaction system is 200~300 μg / L; even more preferably, it is 250 μg / L.

[0019] The optimal choice is when the initial concentration of 6PPD-Q in the reaction system is 100 μg / L, and the initial concentration of Chlorella is 1 × 10⁻⁶. 6 The concentration of Mo2C MXene was calculated as cells / mL and 250 μg / L.

[0020] The culture conditions of the reaction system are suitable for the growth of Chlorella (such as temperature, light intensity, pH value, dissolved oxygen concentration, etc.). For example, natural light and temperature environment can be simulated, or light and temperature can be controlled.

[0021] Optionally, the light intensity is controlled at 3000~5000 lx, the temperature at 20~30℃, and the pH of the reaction system is maintained at 6.5~8.0; the light cycle is controlled as 10~14 hours of white light and 10~14 hours of dark period alternation; the reaction time is 90~100 hours. Further, the light cycle is controlled as 12 hours of white light and 12 hours of dark period alternation.

[0022] Optionally, the Chlorella is cultured as follows:

[0023] Commercially available live Chlorella strains were inoculated at a rate of 10%-20% into BG-11 or equivalent culture medium. The cultures were then statically or with intermittent stirring for 5-7 days under conditions of 3000-5000 lx light intensity, 25-28 ℃ temperature, and pH 6.5-7.5. An initial concentration of 1-5 × 10⁻⁶ was selected. 6 The small Chlorella cells / mL were further processed to ensure the metabolic activity of the algae.

[0024] Optionally, the preparation of the mixture:

[0025] Mo2C MXene suspension was added at a certain concentration to a culture medium containing Chlorella (experimental group), while no Mo2C MXene was added to the blank control group. The culture conditions were suitable for Chlorella growth (such as temperature, light intensity, pH, dissolved oxygen concentration, etc.). This process can achieve uniform distribution of Mo2C MXene on the algal surface and improve the synergistic degradation ability.

[0026] Optionally, the Mo2C MXene suspension is prepared by adding Mo2C MXene into a container filled with sterile water and ultrasonically dispersing it for 40-60 minutes under sterile conditions.

[0027] Optionally, the 6PPD-Q degradation step:

[0028] Add 6PPD-Q at an initial mass concentration of 25-100 μg / L to the prepared blank group and experimental group, respectively. Maintain the reaction under simulated natural light (or controlled light) for 96 hours; control the temperature of the reaction system at 25-30 ℃ and maintain the pH in the neutral or weakly alkaline range;

[0029] During the degradation process, samples can be taken at regular intervals, and the removal rate of 6PPD-Q can be analyzed using HPLC.

[0030] The degradation rate of 6PPD-Q was detected by high-performance liquid chromatography (HPLC), using a C18 column, acetonitrile-water mobile phase, and a detection wavelength of 360 nm for quantitative analysis. Experimental results showed that the efficiency of Chlorella vulgaris with added Mo2C MXene in degrading 6PPD-Q was 30% higher than the control group without added Mo2C MXene within 48 hours.

[0031] This application also provides a formulation for degrading 6PPD-Q, comprising separately packaged Chlorella and Mo2CMXene; in use, the Chlorella strain is inoculated into an algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension, and then the Chlorella suspension is mixed with a Mo2CMXene suspension.

[0032] Optionally, after the Chlorella suspension is mixed with the Mo2C MXene suspension, the concentration of Chlorella is 1~5×10⁻⁶. 8 The concentration of Mo2C MXene was 5-30 mg / L; then it was added to the polluted wastewater at a volume ratio of 1:100.

[0033] This application also provides a mixed agent for degrading 6PPD-Q, said mixed agent being a mixture containing both Chlorella and Mo2C MXene, prepared by the following method:

[0034] Chlorella seedlings were inoculated into algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension. The Chlorella suspension was then mixed with a Mo2C MXene suspension to obtain the mixture.

[0035] Optionally, the culture medium is a conventional algal culture medium rich in nutrients such as nitrogen, phosphorus, and potassium, and the pH value of the culture medium is 6 to 8.

[0036] Optionally, the concentration of Chlorella in the mixture is 1~5×10⁻⁶. 8 cells / mL; the concentration of Mo2C MXene is 5~30 mg / L.

[0037] Optionally, the mixture can be added to the contaminated wastewater at a volume ratio of 1:100.

[0038] This application also provides the application of the aforementioned formulation or the aforementioned mixture in treating water bodies contaminated with 6PPD-Q.

[0039] In summary, this application proposes a novel pollutant degradation method based on microalgae, which can efficiently and safely remove recalcitrant emerging organic pollutants from the environment, demonstrating promising application prospects and widespread value. Experimental results from this invention show that Mo2C MXene, when synergistically treated with Chlorella, significantly enhances the degradation efficiency of 6PPD-Q by Chlorella. Compared to the blank control group without Mo2C MXene, the Chlorella treatment group with added Mo2C MXene exhibited a higher removal rate and faster degradation rate under the same reaction conditions. These results indicate that Mo2C MXene not only has no significant inhibitory effect on the growth of Chlorella but also has a positive effect on promoting its metabolic activity and environmental remediation capacity.

[0040] Therefore, Mo2C MXene can serve as a safe and effective exogenous activator to enhance the environmental adaptability and degradation efficiency of microalgae in complex polluted environments. This invention is the first to verify the potential of Mo2C MXene in promoting the degradation of novel pollutants (such as 6PPD-Q) by Chlorella, providing a theoretical basis and practical foundation for its in-depth research and application in the field of microalgal bioremediation.

[0041] Compared with existing technologies, it has at least one of the following beneficial effects:

[0042] First, this application relates to a method for degrading 6PPD-Q, a novel pollutant in the form of rubber antioxidants, using Chlorella. Chlorella, a microalga widely used in environmental remediation, possesses excellent organic pollutant degradation capabilities under light conditions, and can achieve preliminary degradation and transformation of 6PPD-Q through mechanisms such as absorption, metabolism, and enzymatic reactions.

[0043] Secondly, this invention introduces a novel nanomaterial—Mo2C MXene—and, by synergistically constructing a composite treatment system with Chlorella, significantly improves the degradation efficiency of 6PPD-Q. Mo2C MXene possesses a unique two-dimensional structure, high specific surface area, and excellent electrochemical performance, which can enhance the photosynthetic and metabolic activities of Chlorella, while also participating in electron transfer processes to accelerate pollutant decomposition.

[0044] Finally, this invention provides a safe and effective synergistic remediation strategy of microalgae and nanomaterials. Without inhibiting algal growth, the addition of an appropriate concentration of Mo2C MXene effectively promotes the degradation process of 6PPD-Q, providing a theoretical basis and practical path for expanding the application of molybdenum carbide nanomaterials in water pollution control and microalgal environments. Attached Figure Description

[0045] Figure 1 This is a structural diagram of 6PPD-Q.

[0046] Figure 2 The growth of Chlorella in different treatment groups in Example 1 over 96 hours.

[0047] Figure 3 This is a graph showing the chlorophyll results of Chlorella in different treatment groups in Example 1.

[0048] Figure 4 The standard curve and linear regression equation for 6PPD-Q in Example 1 are shown.

[0049] Figure 5 This is a comparison chart of the degradation efficiency of 6PPD-Q by different treatment groups in Example 2 over 96 hours (data based on liquid chromatography detection).

[0050] Figure 6 This is a graph showing the degradation results of Mo2C MXene alone in Example 2.

[0051] Figure 7 This shows the changes in CYP450 activity in Chlorella vulgaris over 96 hours in Example 3.

[0052] Figure 8 This shows the changes in GST activity in Chlorella vulgaris over 96 hours in Example 3.

[0053] Figure 9 This shows the changes in POD activity in Chlorella vulgaris over 96 hours in Example 3.

[0054] Figure 10 This is a comparison chart of the degradation efficiency of Chlorella 6PPD-Q in different treatment groups after the addition of the CPY450 inhibitor ABT in Example 3 within 96 hours (data based on liquid chromatography detection). Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0057] The structural formula of 6PPD-Q is as follows Figure 1 As shown, it was obtained through retail purchase.

[0058] The molybdenum carbide nanomaterials used were molybdenum carbide nanomaterials (Mo2C MXene), which were obtained through commercial channels. The nanomaterials had a particle size of 30-100 nm and a purity of >95%. The Chlorella strains were also obtained through commercial channels.

[0059] The Mo2C MXene used in the following examples was purchased from Suzhou Youyan New Materials Industry Co., Ltd., with a purity of 99.99%.

[0060] The 6PPD-quinone (6PPD-Q) standard (purity >97%) used in the following examples was purchased from Shanghai Bailingwei Chemical Technology Co., Ltd.

[0061] The culture medium is a conventional algal culture medium rich in nutrients such as nitrogen, phosphorus, and potassium, for example, BG-11 medium can be used.

[0062] Kits for testing the activities of cytochrome P450 (CYP450), glutathione S-transferase (GST), and peroxidase (POD) were purchased from Beijing Solarbio Science & Technology Co., Ltd.

[0063] ABT was purchased from Shanghai McLean Biochemical Technology Co., Ltd.

[0064] Chlorella strains can be obtained commercially; any commercially available Chlorella strain is acceptable.

[0065] As an example, the preferred method of Chlorella combined with molybdenum carbide nanomaterials for the degradation of 6PPD-Q according to the present invention is as follows:

[0066] (1) Preparation of Mo2C MXene suspension:

[0067] Accurately weigh Mo2C MXene using a sterile weighing spoon and weighing paper, pour it into a pre-sterilized conical flask containing deionized water to prepare a Mo2C MXene stock solution or working solution. After sealing the flask, ultrasonically disperse the solution for 40-60 minutes to obtain a Mo2C MXene suspension, and place it in a clean bench for later use.

[0068] (2) Preparation of BG-11 medium and inoculation of Chlorella strains:

[0069] Accurately weigh 1 g of algal culture medium (product number: Q / HNJX236-2021) using a sterile weighing spoon and weighing paper, pour it into a pre-sterilized volumetric flask containing 1 L of deionized water to prepare BG-11 culture medium, and place it in a clean bench for later use.

[0070] Active Chlorella strains were inoculated into BG-11 medium and cultured statically or with intermittent stirring for 5-7 days under conditions of 3000-5000 lx light intensity, 25-28 ℃ temperature, and pH 6.5-7.5. An initial concentration of 1 × 10⁻⁶ was selected. 6 The small Chlorella cells / mL were further processed to ensure the metabolic activity of the algae.

[0071] (3) Preparation of exposed samples:

[0072] The prepared Mo2C MXene suspension was added to Chlorella and BG-11 medium, and quickly shaken to dispense into 50 mL Erlenmeyer flasks. Each flask was then filled with 50 mL of medium. The control group was treated with an equal volume of deionized water instead of the Mo2C MXene suspension. Both the control and experimental groups were treated with 6 PPD-Q contaminant at a concentration of 25-100 μg / L.

[0073] (4) Cultivation of Chlorella:

[0074] The prepared conical flasks were transferred to an artificial climate chamber for incubation, with a photoperiod of 12 hours of light / 12 hours of darkness. Tests were conducted every 24 hours, for a total of four tests.

[0075] The following is a description using specific embodiments:

[0076] Example 1

[0077] A method for degrading 6PPD-Q specifically includes the following steps:

[0078] (1) Preparation of Mo2C suspension

[0079] Accurately weigh 10 mg of Mo2C MXene using a sterile weighing spoon and weighing paper, pour it into a pre-sterilized 100 mL volumetric flask, add water to make up to 100 mL, seal the flask, and sonicate for 60 min to obtain a Mo2C suspension (solution A, 0.1 mg / mL). Transfer the suspension to a 200 mL Erlenmeyer flask and place it on a clean bench for later use.

[0080] (2) Preparation of BG-11 culture medium

[0081] Accurately weigh 1g of solid algal culture medium using a sterile weighing spoon and weighing paper, pour it into a pre-sterilized volumetric flask containing 1L of deionized water to prepare BG-11 culture medium, and sonicate for 5-10 minutes to obtain BG-11 culture medium mixture (solution B, 1g / L).

[0082] (3) Preparation of exposed samples

[0083] Prepare Chlorella seed strains (Chlorella proteoglycans, Chlorella pyrenoidosa Inoculate 15% of the culture medium (solution B) and incubate under constant temperature conditions (usually 25°C ± 2°C), selecting an initial concentration of 1 × 10⁻⁶. 6 Chlorella suspension (solution C) with cells / mL. Add 125 μL of Mo2C MX ene suspension (solution A) prepared in step (1) to 50 mL of Chlorella suspension (a mixture of Chlorella and BG-11 medium, solution C) to obtain a mixed solution (solution D).

[0084] A reaction system was constructed by adding 6PPD-Q to a mixed solution (solution D). The concentration of Mo2C MXene in the reaction system was 250 μg / L. The initial concentrations of 6PPD-Q in the reaction system were changed to 25 μg / L, 50 μg / L, and 100 μg / L, respectively, to study its degradation effect during algal exposure.

[0085] (4) Cultivation of Chlorella

[0086] After adding 6PPD-Q, maintain a light intensity of 5000 lx during cultivation, using a 12-hour light-12-hour dark cycle. Use appropriate stirring equipment to maintain the homogeneity of the culture medium and promote the full growth of Chlorella.

[0087] (5) Effects of 6PPD-Q on the growth of Chlorella

[0088] The optical density of Chlorella at 680 nm (OD680) was measured using a spectrophotometer at 0, 24, 48, 72 and 96 h.

[0089] The results are as follows Figure 2 As shown in the growth curves, the growth trends of Chlorella in each concentration group were basically consistent, all exhibiting typical growth curve characteristics, namely, experiencing a lag phase, a logarithmic growth phase, and a stationary phase. This indicates that under light conditions, 0-100 μg / L concentrations of 6PPD-Q did not significantly interfere with the growth process of Chlorella, meaning that Chlorella could carry out normal growth and metabolic activities. However, in the experimental groups with 100 μg / L 6PPD-Q and 250 μg / L Mo2C MXene, a significant increase in the number of Chlorella cells was observed during the experimental period.

[0090] Take 10 mL of the algal solution after 96 h of exposure, then place it in a centrifuge tube and centrifuge at 3600 r·min. -1 Centrifuge for 10 min under the specified conditions, remove the supernatant, add 5 mL of 90% acetone solution, shake well, and place in the dark for 24 h. After the process, centrifuge the solution at 3600 r·min. -1 Centrifuge for 10 min under the specified conditions, collect the supernatant, and measure its absorbance at 664 nm and 647 nm using a spectrophotometer. Calculate the contents of chlorophyll a and chlorophyll b in the algae using the following formula:

[0091] Chlorophyll a = 11.93 E 664 - 1.93 E 647 ;

[0092] Chlorophyll b = 20.36 E 647 - 5.50 E 664 ;

[0093] Where E 664 E represents the absorbance of the supernatant at 664 nm; where E 647 The absorbance value of the supernatant at 647 nm is given.

[0094] The results are as follows Figure 3 As shown, there was no significant difference in the content of either chlorophyll a or chlorophyll b. This means that 6PPD-Q does not significantly affect the synthesis or degradation process of chlorophyll in Chlorella within this concentration range, thus indicating that the photosynthetic system of Chlorella was not significantly disturbed. In the experimental group with a 6PPD-Q concentration of 100 μg / L and a Mo2C MXene concentration of 250 μg / L, an increase in the content of chlorophyll a and chlorophyll b in Chlorella was observed.

[0095] Example 2

[0096] A method for determining the efficiency of Chlorella in degrading 6PPD-Q specifically includes the following steps:

[0097] Detection of 6PPD-Q concentration by liquid chromatography:

[0098] The degradation efficiency of 6PPD-Q was compared between the control group with added Mo2C MXene and the blank group (without added Mo2C MXene) using liquid chromatography.

[0099] (1) Establishment and analysis of liquid chromatography method for the detection of 6PPD-Q concentration

[0100] An Agilent 1260 high-performance liquid chromatograph equipped with a DAD (ultraviolet-visible) detector was used, employing a C18 column (4.6 × 150 mm, 5 μm). The mobile phase consisted of 80% acetonitrile and 20% pure water. The flow rate was 1.0 mL / min, the detection wavelength was 360 nm, the injection volume was 10 μL, and the retention time was 3 min.

[0101] (2) Plotting the 6PPD-Q standard curve

[0102] Weigh a certain amount of high-purity 6PPD-Q (>97%) and prepare a 100 mg / L stock solution with acetonitrile. Store at 4 °C protected from light.

[0103] The stock solution was serially diluted to prepare a series of standard solutions of different concentrations (1, 5, 10, 25, 50, 100, 200, 300, 400, 500, 1000 μg / L).

[0104] Inject standard solutions of different concentrations separately and record their peak area values.

[0105] A standard curve was plotted with concentration on the horizontal axis and peak area on the vertical axis. The regression equation is as follows:

[0106] A=kC+b

[0107] Where A is the peak area, C is the 6PPD-Q concentration, k is the slope, and b is the intercept; R 2A value ≥ 0.999 indicates a good linear relationship.

[0108] In this embodiment, the standard curve and linear regression equation of 6PPD-Q are as follows: Figure 4 As shown.

[0109] (3) Actual sample testing.

[0110] Sample pretreatment:

[0111] The initial concentration of Chlorella in the experimental system was 1 × 10⁻⁶. 6 The cells / mL and Mo2C MXene concentration were added to a final concentration of 250 μg / L. The experimental group settings for different concentrations of 6PPD-Q were the same as in Example 1, and the culture process was the same as in Example 1. In addition, an experimental group was added without Chlorella, but with only 250 μg / L Mo2C MXene added. 50 mL of deionized water was used to replace solution C. The initial concentration of 6PPD-Q in the reaction system was 100 μg / L, and the reaction conditions were the same as in Example 1.

[0112] Take 0.5 mL of sample from the experimental system, add an equal volume of acetonitrile, mix thoroughly, centrifuge (12000 rpm, 5 min), and filter the supernatant (0.22 μm membrane) for later use.

[0113] Inject the sample under the optimized conditions in step (1) and record the retention time and peak area of ​​6PPD-Q. Substitute the sample peak area into the standard curve equation to calculate the corresponding 6PPD-Q concentration.

[0114] Degradation rate calculation formula:

[0115] Degradation rate (%) = (C0 - C) t ) / C0×%.

[0116] Where C0 is the initial concentration of 6PPD-Q, C t The concentration of 6PPD-Q was measured at time point t.

[0117] The results are as follows Figure 5 As shown, in all concentration groups, the concentration of 6PPD-Q decreased with increasing exposure time, indicating that both the Chlorella system and the Chlorella + Mo2C system could degrade 6PPD-Q. However, by comparison, it can be found that under the same exposure time and initial concentration, the rate and magnitude of the decrease in 6PPD-Q concentration in the Chlorella + Mo2C system were significantly greater than those in the Chlorella system. For example, when the initial concentration of 6PPD-Q was 25 μg / L, after 24 hours of exposure, the remaining 6PPD-Q concentration in the Chlorella system alone was 22.1 μg / L, while the remaining 6PPD-Q concentration in the Chlorella + Mo2C system was 9.42 μg / L. Figure 5(A); When the initial concentration was 50 μg / L, after 24 h of exposure, the remaining 6PPD-Q concentration in the Chlorella-only system was 48.3 μg / L, while the remaining 6PPD-Q concentration in the Chlorella + Mo2C system was 17.9 μg / L. Figure 5 (B); while when the initial concentration was 100 μg / L, after 24 h of exposure, the remaining 6PPD-Q concentration in the Chlorella-only system was 80.3 μg / L, while the remaining 6PPD-Q concentration in the Chlorella + Mo2C system was 40.1 μg / L. Figure 5 (C)

[0118] The degradation results of adding Mo2C MXene alone are as follows: Figure 6 As shown in the results, the experimental group with Mo2C MXene added alone did not have the ability to degrade 6PPD-Q.

[0119] The above results indicate that adding Mo2C MXene alone does not have the ability to degrade 6PPD-Q; Chlorella has a certain removal capacity for 6PPD-Q, although the removal rate decreases with increasing initial concentration, the absolute amount of 6PPD-Q removed per unit time increases; after adding Mo2C MXene, the degradation efficiency of 6PPD-Q by Chlorella is further significantly improved, indicating that Mo2C MXene has a synergistic effect on the degradation of 6PPD-Q by Chlorella.

[0120] Example 3

[0121] A method for measuring changes in enzyme activity within Chlorella vulgaris specifically includes the following steps:

[0122] Using a commercially available enzyme activity assay kit, the activities of key detoxification and antioxidant enzymes in Chlorella were measured at four time points (24 h, 48 h, 72 h, and 96 h) under different concentrations of 6PPD-Q (0, 25, 50, and 100 μg / L). These enzymes included glutathione S-transferase (GST), peroxidase (POD), and cytochrome P450 (CYP450).

[0123] (1) Sample collection and processing

[0124] The experimental system and treatment process were the same as in Example 1. At 24, 48, 72 and 96 hours after the start of treatment, 1 mL of algal solution was taken from each group, centrifuged at 12000 rpm for 5 min, the supernatant was discarded and the algal cell precipitate was collected.

[0125] Resuspend in 1 mL of physiological saline, centrifuge again (3000 rpm, 4 ℃, 10 min), and use the supernatant as the enzyme source for subsequent enzyme activity detection.

[0126] (2) Enzyme activity detection

[0127] Taking CYP450 activity detection as an example:

[0128] The kit employs a one-step sandwich enzyme-linked immunosorbent assay (ELISA) using a double antibody. Sample, standard, and HRP-labeled detection antibody are added sequentially to microwells pre-coated with cytochrome P450 (CYP450) antibody, followed by incubation and thorough washing. The substrate TMB is used for color development; TMB is converted to blue by peroxidase, and then to yellow under acidic conditions. The color intensity is positively correlated with the cytochrome P450 (CYP450) content in the sample. The absorbance (OD value) is measured at 450 nm using a microplate reader to calculate sample activity.

[0129] (3) Enzyme inhibition experiment

[0130] The experiment requires the use of a CYP450 enzyme inhibitor, namely ABT. After adding 5 μmol / L ABT to each sample, the above experiment was repeated.

[0131] from Figure 7 As can be seen, CYP450 is extremely sensitive to 6PPD-Q, and its activity increases with increasing 6PPD-Q concentration. For example, compared with the control group, CYP450 activity increased by 12.3%, 13.4%, and 16.1% under exposure to 25, 50, and 100 μg / L 6PPD-Q, respectively. In the experimental group containing 250 μg / L Mo2C MXene at the same 6PPD-Q concentration, CYP450 activity was further enhanced, increasing by 13.3%, 15.7%, and 21.3%, respectively. This indicates that 6PPD-Q has a significant inducing effect on CYP450 activity, and Mo2C MXene can further enhance CYP450 activity.

[0132] like Figure 8 As shown, GST activity increased in all 6PPD-Q treatment groups. For example, compared with the control group, GST activity increased by 11.6%, 13.1%, and 14.9% in the experimental groups with 25, 50, and 100 μg / L 6PPD-Q and 100 μg / L 6PPD-Q and 250 μg / L Mo2C MXene, respectively. In the experimental group with the same 6PPD-Q concentration and containing 250 μg / L Mo2C MXene, GST activity was further enhanced by 13.5%, 16.3%, and 18.1%, respectively, indicating that GST can participate in 6PPD-Q conversion, and Mo2C MXene can promote this process.

[0133] like Figure 9 As shown, in the experimental groups with 25, 50, and 100 μg / L 6PPD-Q and 100 μg / L 6PPD-Q and 250 μg / L Mo2C MXene, the activity of POD increased by 11.7%, 12.4%, and 13.9%, respectively. In the experimental group with the same 6PPD-Q concentration and containing 250 μg / L Mo2C MXene, the activity of POD was further enhanced by 12.8%, 13.9%, and 15.5%, respectively. This indicates that POD can also participate in the conversion of 6PPD-Q, and Mo2C MXene can also promote this process.

[0134] To further verify the important role of P450 enzyme in the degradation of 6PPD-Q, inhibition experiments were conducted, such as... Figure 10 As shown, the degradation rate of 6PPD-Q was significantly reduced after the addition of ABT. For example, in the experimental group with a 6PPD-Q concentration of 100 μg / L and a Mo2C MXene concentration of 250 μg / L, the remaining 6PPD-Q concentrations after 24, 48, 72, and 96 h of exposure were 40.1, 16.3, 16.2, and 10.7 μg / L, respectively; while in the system containing ABT, the remaining 6PPD-Q concentrations after 24, 48, 72, and 96 h of exposure were 72.8, 52.4, 42.6, and 35.7 μg / L, respectively. This indicates that the degradation efficiency of 6PPD-Q was significantly inhibited after the addition of ABT, suggesting that P450 enzymes play an important role in the degradation of 6PPD-Q.

[0135] In summary, this application provides a novel method for the synergistic degradation of 6PPD-Q by Chlorella using molybdenum carbide nanomaterials (Mo2C MXene). This method significantly enhances the degradation capacity of Chlorella for 6PPD-Q and improves degradation efficiency by introducing Mo2C MXene. Mo2C MXene, as a novel two-dimensional transition metal carbide material, possesses high specific surface area, good electrical conductivity, and excellent adsorption and catalytic properties. It can play an exogenous stimulating role in microalgal metabolism, promoting the expression of key enzymes and thus accelerating the biodegradation process of pollutants. This application provides a new theoretical basis and technical pathway for the application of Mo2C MXene in microalgae-pollutant synergistic remediation systems, and has significant practical significance and promotional value for the green treatment of new pollutants and the development of microalgal environmental technologies.

[0136] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The methods disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments; relevant parts can be found in the method section.

Claims

1. A method for degrading 6PPD-Q by Chlorella combined with carbonized molybdenum nanomaterials, characterized in that, include: Chlorella strains were inoculated into an algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension. The Chlorella suspension was mixed with a Mo2C MXene suspension to obtain a mixture containing both Chlorella and Mo2C MXene. The mixture was added to polluted water containing 6PPD-Q to form a reaction system, and reacted under suitable conditions for Chlorella growth to degrade 6PPD-Q in the polluted water.

2. The method of claim 1, wherein, The particle size range of the Mo2C MXene is 10 nm to 100 nm.

3. The method of claim 1, wherein, The initial concentration of chlorella in the reaction system is 1-5*10 6 cells / mL; the concentration of Mo2C MXene in the reaction system is 50-300 μg / L; and the initial concentration of 6PPD-Q in the reaction system is 25-100 μg / L.

4. The method of claim 3, wherein, The final concentration of Mo2C MXene in the reaction system is 200~300 μg / L.

5. The method of claim 1, wherein, The suitable conditions for the growth of Chlorella are: light intensity of 3000~5000 lx, temperature of 20~30℃, and pH of the reaction system maintained at 6.5~8.0; the light cycle is 10~14 hours of white light and 10~14 hours of dark period; and the reaction time is 90~100h.

6. Application of Mo2C MXene in enhancing the degradation of 6PPD-Q by Chlorella.

7. A method for synergistically degrading 6PPD-Q by Chlorella vulgaris using molybdenum carbide nanomaterials, characterized in that, include: The molybdenum carbide nanomaterial Mo2C MXene was added to polluted water containing both Chlorella and 6PPD-Q; or the molybdenum carbide nanomaterial Mo2C MXene and Chlorella were added synchronously or asynchronously to polluted water containing 6PPD-Q; and the 6PPD-Q was degraded under natural light and temperature.

8. A formulation for degrading 6PPD-Q, characterized in that, It includes separately packaged Chlorella and Mo2C MXene; when using, the Chlorella strain is inoculated into an algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension, and then the Chlorella suspension is mixed with the Mo2C MXene suspension.

9. A mixed agent for degrading 6PPD-Q, characterized by, The mixed agent is a mixture containing both Chlorella and Mo2C MXene, and is prepared by the following method: Chlorella seedlings were inoculated into algal culture medium and cultured under constant temperature conditions to obtain a Chlorella suspension. The Chlorella suspension was then mixed with a Mo2C MXene suspension to obtain the mixture.

10. The application of the formulation of claim 8 or the mixture of claim 9 in the treatment of water bodies contaminated with 6PPD-Q.

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