Method for detecting and treating new pollutants in underground water

Abstract

The invention belongs to the technical field of groundwater pollution treatment, and discloses a method for detecting and treating new groundwater pollutants, which combines a phosphorus functionalized composite material with a nano vesicle technology, prolongs the acting time of the phosphorus functionalized composite material in groundwater, improves the degradation rate of the new pollutants, and improves the treatment effect of the new pollutants. According to the present invention, the retention reaction time of the material in the polluted area is prolonged, the target pollutants are effectively captured by using the biodegradability of the polylactic acid so as to reduce the risk of secondary pollution, and the polylactic acid is combined with the ferrihydrite and the nanometer TiO2 to form the composite system with the catalytic activity so as to synergistically promote the oxidative degradation of the micro-plastic.

Description

Technical Field

[0001] This invention belongs to the field of groundwater pollution control technology, specifically relating to a method for detecting and treating new pollutants in groundwater. Background Technology

[0002] With the widespread use of plastic products, a large number of plastic particles enter the groundwater system through surface runoff, sewage discharge, and landfill, forming microplastic particles. These microplastics easily adsorb persistent organic pollutants, heavy metals, and other toxic substances on their surfaces, increasing the risk of them entering organisms. Harmful chemicals such as plasticizers, antioxidants, and stabilizers added to some plastic products may be released from microplastics in the environment, causing direct toxicity to organisms and posing a serious threat to human health. Therefore, the detection and rapid treatment of microplastic content in groundwater are urgent problems that need to be solved.

[0003] Traditional methods for microplastic degradation include physical recycling, which is inefficient and costly; chemical oxidation, which generally requires the use of toxic chemical reagents and poses a risk of secondary pollution; and biodegradation, which is environmentally friendly, has a low rate and is difficult to meet practical needs. Summary of the Invention

[0004] To address the limitations of traditional microplastic degradation methods, such as low efficiency and high cost of physical recycling, the risk of secondary pollution from chemical oxidation (which typically requires toxic chemicals), and the slow rate of biodegradation (while environmentally friendly), this invention provides a method for detecting and treating new pollutants in groundwater. This method overcomes the limitations of traditional microplastic degradation methods and, by introducing novel photocatalytic mineral composite materials and nanovesicle structures, offers an efficient and sustainable new approach to solving microplastic pollution.

[0005] The technical solution adopted in this invention is as follows: A method for detecting new pollutants in groundwater, comprising the following steps: 1) Take a water sample, add (25-30)% hydrogen peroxide in a volume ratio of (10-15):1 to the water sample, shake at a constant temperature, add saturated sodium chloride solution and mix, shake thoroughly, let stand, and collect the supernatant. 2) Filter the supernatant, dry the filter membrane, and collect the filter residue; 3) Perform content and optical analysis on the filter residue.

[0006] This invention pre-treats groundwater samples by oxidizing, settling, and filtering them, effectively eliminating the influence of organic matter and minerals in the groundwater on the monitoring of new pollutants, reducing background interference, and improving the reliability of monitoring results.

[0007] Furthermore, the isothermal oscillation conditions in step 1) are isothermal oscillation at 50~60℃ and 100~120rpm for 12~18h.

[0008] Furthermore, in step 2), the filter membrane is a glass fiber filter membrane with a pore size of 1~5μm.

[0009] Furthermore, in step 2), the settling time is >24h.

[0010] A method for treating new pollutants in groundwater includes the following steps: S1. Dissolve Fe(NO3)3·9H2O in water, add nano TiO2 powder and polylactic acid microplastic particles, disperse by ultrasonication, slowly add alkaline solution to adjust pH to 7.0~8.0, stir, after the reaction is complete, centrifuge, take the precipitate and wash it to obtain composite colloid; S2. Add the composite colloid to 20~22nM K2HPO4 solution, adjust the pH to 6.0~6.2, and react with shaking in the dark for 48~50h to obtain the phosphorus-functionalized composite material; S3. The phosphorus-functionalized composite material obtained in S2 and lecithin were dissolved in chloroform, rotary evaporated, and then PBS buffer was added. After sonication, the mixture was extruded using a high-pressure homogenizer and dialyzed to obtain nanovesicles. S4. Add the nanovesicles obtained in S3 to the sampled groundwater to degrade the microplastic particles.

[0011] This invention utilizes the biodegradability of polylactic acid (PLA) to effectively capture target pollutants, reducing the risk of secondary pollution. Simultaneously, it combines with ferrous sulfate and nano-TiO2 to form a catalytically active composite system, synergistically promoting the oxidative degradation of microplastics. Furthermore, it interacts with phosphate groups, further enhancing the composite material's ability to capture microplastics and strengthening its structural stability. Combining phosphorus-functionalized composite materials with nanovesicle technology extends the contact time of the phosphorus-functionalized composite material in groundwater, increasing the degradation rate of new pollutants and prolonging the material's residence time in polluted areas.

[0012] Furthermore, the polylactic acid microplastic particles in S1 have a particle size of 50~100μm.

[0013] Furthermore, in S1, the mixing mass ratio of Fe(NO3)3·9H2O, nano TiO2 powder and polylactic acid microplastic particles is (20~25):(2~3):(0.8~1).

[0014] Furthermore, in S3, the mass ratio of the phosphorus-functionalized composite material to lecithin is (0.5~1.5):(8~10).

[0015] Furthermore, in S3, the pH of the PBS buffer is 7.2~7.4. Furthermore, in S2, the amount of K2HPO4 solution added is 2~3 g / L.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1) This invention effectively eliminates the influence of organic matter and minerals in groundwater on the monitoring of new pollutants by pre-treating the sampled groundwater, reducing background interference and improving the reliability of monitoring results.

[0017] 2) This invention utilizes the biodegradability of polylactic acid to effectively capture target pollutants, reducing the risk of secondary pollution. At the same time, it combines with ferrous sulfate and nano-TiO2 to form a catalytically active composite system, which synergistically promotes the oxidative degradation of microplastics. In addition, it interacts with phosphate groups to further enhance the composite material's ability to capture microplastics and enhance the structural stability of the material itself.

[0018] 3) This invention combines phosphorus-functionalized composite materials with nanovesicle technology to extend the contact time of phosphorus-functionalized composite materials in groundwater, improve the degradation rate of new pollutants, and extend the residence reaction time of materials in polluted areas. Detailed Implementation

[0019] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0020] The present invention will be further described below with reference to embodiments.

[0021] Example 1 1) New pollutant detection Groundwater was sampled, and 1000 vol% of 30% hydrogen peroxide solution was added. The mixture was then placed in a constant temperature shaker at 60℃ and 100 rpm and shaken for 12 hours. After that, saturated sodium chloride solution was added, and the mixture was shaken thoroughly. After stirring evenly, the mixture was allowed to stand for precipitation for 24 hours. The supernatant was taken and filtered through a glass fiber membrane with a pore size of 1 μm. The filtered glass fiber membrane was washed and dried, and the filter residue was collected. The filter residue was subjected to optical analysis and content detection.

[0022] 2) Treatment of new pollutants S1. Dissolve 40g Fe(NO3)3·9H2O in 500ml of water, add 4g PLAMPs and 2g nano TiO2 powder, sonicate for 30min, after uniform dispersion, slowly add 1M KOH, adjust pH to 7.0, magnetically stir at 25℃ for 1h, centrifuge at 5000rpm for 10min, take the precipitate, wash with water 5 times to obtain composite colloid.

[0023] S2. Take 1.2g of composite colloid and add it to 500ml of 20nM K2HPO4 solution. Adjust the pH to 6.0, shake and react in the dark for 48h, and freeze dry to obtain phosphorus-functionalized composite material.

[0024] S3. Take 1g of phosphorus-functionalized composite material and 10g of lecithin, mix and dissolve in chloroform, remove the chloroform by rotary evaporation, add PBS buffer at pH=7.4, sonicate for 30min, and extrude using a high-pressure homogenizer to obtain nanovesicles.

[0025] S4. Add the above nanovesicles to groundwater samples and periodically sample and measure the degradation rate of microplastic particles after 28 days.

[0026] Comparative Example 1 The only difference between this comparative example and Example 1 is that nano-TiO2 powder is not added in S1 in this comparative example; the rest of the process is the same as in Example 1.

[0027] Table 1 Effect of the addition of nano-TiO2 powder on degradation performance <![CDATA[Whether to add nano-TiO2 powder]]> COD removal rate % TOC removal rate % Example 1 yes 34.5 29.5 Comparative Example 1 no 28.6 22.3 The data in Table 1 show that the addition of nano-TiO2 powder can effectively improve the removal rates of COD and TOC, and enhance the degradation efficiency of the composite material for microorganisms. The reason for this is that the introduction of nano-TiO2 changes the surface properties of the ferrohydrate-PLAMPs composite material, making it rougher and with more active sites. At the same time, ferrohydrate acts as a carrier to fix nano-TiO2, reducing the aggregation of TiO2 particles. It also provides additional adsorption capacity and buffering effect, preventing TiO2 from reacting unnecessarily with other components in the environment, thus significantly improving the degradation rate of microplastics.

[0028] Comparative Example 2 The only difference between this comparative example and Example 1 is that the phosphorus-functionalized composite material is not encapsulated in this comparative example, i.e., S4 is not performed. All other processes are the same as in Example 1.

[0029] Table 2. Impact of vesicle encapsulation technology on the treatment of new pollutants. vesicles present or absent COD removal rate % TOC removal rate % Example 1 have 34.5 29.5 Comparative Example 2 none 28.6 22.3 The data in Table 2 show that vesicle encapsulation of phosphorus-functionalized composite materials significantly increases the removal rates of COD and TOC, effectively enhancing the degradation capacity of microplastics. The reason for this is that vesicle encapsulation of phosphorus-functionalized composite materials can effectively maintain the stability and dispersibility of nano-TiO2, further promoting the oxidative degradation process. At the same time, it can also increase the contact sites between microplastics and phosphorus-functionalized composite materials, enhancing the sustainability of the degradation reaction.

[0030] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0031] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A method for detecting new pollutants in groundwater, characterized in that, Includes the following steps: 1) Take a water sample, add (25-30)% hydrogen peroxide in a volume ratio of (10-15):1 to the water sample, shake at a constant temperature, add saturated sodium chloride solution and mix, shake thoroughly, let stand, and collect the supernatant. 2) Filter the supernatant, dry the filter membrane, and collect the filter residue; 3) Perform content and optical analysis on the filter residue.

2. The method for detecting new pollutants in groundwater according to claim 1, characterized in that, The isothermal oscillation conditions in step 1) are 50~60℃ and 100~120rpm for 12~18h.

3. The method for detecting new pollutants in groundwater according to claim 1, characterized in that, In step 2), the filter membrane is a glass fiber filter membrane with a pore size of 1~5μm.

4. The method for detecting new pollutants in groundwater according to claim 1, characterized in that, In step 2), the settling time is >24h.

5. A method for treating microplastic particles detected by the detection method according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Dissolve Fe(NO3)3·9H2O in water, add nano TiO2 powder and polylactic acid microplastic particles, disperse by ultrasonication, slowly add alkaline solution to adjust pH to 7.0~8.0, stir, after the reaction is complete, centrifuge, take the precipitate and wash it to obtain composite colloid; S2. Add the composite colloid to 20~22nM K2HPO4 solution, adjust the pH to 6.0~6.2, and react with shaking in the dark for 48~50h to obtain the phosphorus-functionalized composite material; S3. The phosphorus-functionalized composite material obtained in S2 and lecithin were dissolved in chloroform, rotary evaporated, and then PBS buffer was added. After sonication, the mixture was extruded using a high-pressure homogenizer and dialyzed to obtain nanovesicles. S4. Add the nanovesicles obtained in S3 to the groundwater samples to degrade the microplastic particles.

6. The method for treating new groundwater pollutants according to claim 5, characterized in that, The polylactic acid microplastic particles in S1 have a particle size of 50~100μm.

7. The method for treating new groundwater pollutants according to claim 5, characterized in that, In S1, the mass ratio of Fe(NO3)3·9H2O, nano TiO2 powder and polylactic acid microplastic particles is (20~25):(2~3):(0.8~1).

8. A method for treating new groundwater pollutants according to claim 5, characterized in that, In S3, the mass ratio of phosphorus-functionalized composite material to lecithin is (0.5~1.5):(8~10).

9. A method for treating new groundwater pollutants according to claim 5, characterized in that, In S3, the pH of the PBS buffer is 7.2~7.

4.

10. A method for treating new groundwater pollutants according to claim 5, characterized in that, In S2, the amount of K2HPO4 solution added is 2~3 g / L.