Method for degrading tire and tire antioxidant pollution product by adopting wax worms

Abstract

The invention relates to a method for degrading tires and tire antioxidant pollution products, in particular to a method for degrading tires and tire antioxidant pollution products through wax worms. The invention aims to solve the problems that tires cannot be directly decomposed in a refuse landfill, a large amount of 6PPDQ is adsorbed on the surfaces of waste tires and fine crushing surfaces of the waste tires, and the environment can be influenced by single or coexistence of the tires and the 6PPDQ. The method comprises the following steps: step 1, constructing a degradation system; and 2, collecting the wax insect excrement in the container in the test period, analyzing the polymerization degree, functional groups, crystallinity and chemical components of residual high polymers in the excrement, evaluating the degradation effect, measuring residual 6PPDQ in the excrement, and evaluating the removal effect of wax insect bodies on the 6PPDQ under the condition that the 6PPDQ is adsorbed on the surface of a tire. The invention belongs to the technical field of pollution treatment.

Description

Technical Field

[0001] This invention relates to a method for degrading tire and tire antioxidant pollution products, belonging to the field of pollution treatment technology. Background Technology

[0002] Tires are primarily composed of natural and synthetic rubber, most of which cannot be directly decomposed in landfills. To stabilize tire performance, antioxidants and flame retardants are indispensable additives in tire production. N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is one of the most widely used antioxidants. During tire wear, it can oxidize into the toxic substance 6PPD-quinone (6PPDQ), which causes acute mortality in salmon at low concentrations (95 ng / L). Waste tires and their finely fragmented surfaces adsorb large amounts of 6PPDQ; both alone and in combination can have immeasurable environmental impacts. Therefore, the treatment of waste tires and the safe conversion of 6PPDQ adsorbed on their surfaces are key aspects of waste management.

[0003] Sunlight is one of the key factors causing the conversion of 6PPD to 6PPDQ. Studies have shown that under 254nm ultraviolet light irradiation, 94% of 6PPDQ in environmental water can be eliminated within 40 minutes. However, ultraviolet light with wavelengths in the 100-280nm range is almost completely absorbed by the ozone layer and cannot reach the ground. 6PPDQ in the environment still needs to be degraded by organisms.

[0004] Insects, as consumers and primary decomposers in the food chain, play a crucial role in the environmental migration and transformation of pollutants. In recent years, waxworms (larvae of Galleria mellonella) have received widespread attention due to their excellent plastic degradation capabilities. Tires are a significant component of marine microplastics, thus waxworms have great potential as “biodegraders” for tires and 6PPDQ. Summary of the Invention

[0005] To address the problem that tires cannot be directly decomposed in landfills, and that waste tires and their fine surfaces adsorb a large amount of 6PPDQ, both of which can impact the environment whether alone or in coexistence, this invention proposes a method for degrading tires and tire antioxidant pollutants using wax insects.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: The steps of the present invention include:

[0007] Step 1: Constructing a degradation system;

[0008] Step 2: Collect waxworm feces from the container during the test period, analyze the degree of polymerization, functional groups, crystallinity and chemical composition of the polymer residues in the feces, evaluate the degradation effect, and measure the residual 6PPDQ in the feces to evaluate the removal effect of waxworms on the tire surface when adsorbed.

[0009] Furthermore, the specific process for constructing the degradation system in step 1 is as follows:

[0010] Step 101: Set multiple vent holes at the top of the culture container to ensure air circulation and exchange between the inside and outside of the container;

[0011] Step 102: Place the crushed tire debris, which has absorbed 6 PPDQ, into an incubation container;

[0012] Step 103: Add waxworms into the culture container.

[0013] Furthermore, in step 102, the length of the tire debris is 2mm to 3mm.

[0014] Furthermore, in step 103, the density of waxworms introduced into the culture container is 50 per liter.

[0015] Furthermore, the experimental period in step 2 is 30 days.

[0016] The beneficial effects of this invention are as follows: Tires treated with waxworms exhibit monomer shedding, altered chemical composition, changes in functional groups, and increased crystallinity, significantly altering the tire's properties. Secondly, although waxworms lose their depolymerization effect on tire polymer chains after high-concentration adsorption of the pollutant 6PPDQ, they can still modify the tire's microstructure (chemical composition, functional groups, and crystallinity). Furthermore, waxworms consume more "tires + 6PPDQ" than they consume the tires themselves, and their growth and development do not produce more harmful effects compared to the tire-fed group. Waxworms can degrade tires and their adsorbed pollutants. The modified tire debris can be further coupled with conventional polymer treatment methods to further achieve polymer chain depolymerization, providing a practical and efficient method for the treatment of waste tires. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the residual 6PPDQ concentration in waxworms and the fitted metabolic kinetic curve.

[0018] Figure 2 This is a matrix-assisted laser desorption / ionization time-of-flight mass spectrum;

[0019] Figure 3 It is an X-ray diffraction pattern;

[0020] Figure 4 It is a thermogravimetric / thermogravimetric differential diagram;

[0021] Figure 5 It is an infrared spectrum;

[0022] Figure 6 The following data are presented: (A) the consumption of tires and "tire + 6PPDQ" tires by waxworms; (B) the mortality rate, larval weight, and pupation rate of waxworms under the feeding control, starvation control, tire feeding, and "tire + 6PPDQ" feeding conditions. Detailed Implementation

[0023] Specific implementation method one: as follows Figures 1 to 6 As shown, a method for degrading tire and tire antioxidant contaminants using waxworms includes the following steps:

[0024] Step 1: Constructing the degradation system; the specific process is as follows:

[0025] Step 101: Set multiple vent holes at the top of the culture container to ensure air circulation and exchange between the inside and outside of the container;

[0026] Step 102: Place the crushed tire debris that has absorbed 6 PPDQ into a culture container; the length of the tire debris is 2mm to 3mm.

[0027] Step 103: Add waxworms to the culture container; the density of waxworms added to the culture container is 50 insects / liter;

[0028] Step 2: Collect waxworm feces from the container during the test period. Analyze the degree of polymerization, functional groups, crystallinity, and chemical composition of the polymer residues in the feces to evaluate the degradation effect. At the same time, measure the residual 6PPDQ in the feces to evaluate the removal effect of waxworms on the tire surface when it is adsorbed. The test period is 30 days.

[0029] Example

[0030] Degradation assessment of 6PPDQ by waxworms

[0031] Approximately 250 mg of waxworms (purity ≥97%) were used for 6PPDQ degradation under constant temperature and humidity (27℃) and complete darkness. The tested waxworms were exposed to contaminants via forced oral injection (approximately 7 μg ingested). Residual 6PPDQ was extracted at 1, 2, 3, 4, 8, 12, 24, 36, and 48 h after exposure, and purified using ethylenediamine-N-propyl sulfate, anhydrous magnesium sulfate, and C18, respectively. Accurate determination was performed using high-performance liquid chromatography-mass spectrometry (HPLC-MS / MS), and the degradation efficiency was calculated.

[0032] The results showed that waxworms metabolize 6PPDQ via first-order kinetics. Figure 1The metabolic constant is 0.06, and the half-life is 11.55 hours. The specific metabolic kinetic model is as follows (Adj.R). 2 =0.9349).

[0033] ln[6PPDQ]=-0.06t+1.873.

[0034] Degradation assessment of wax beetles on tires and "Tire + 6PPDQ"

[0035] Tire and Adsorption Experiment:

[0036] Brand new commercially available tires were cut into 2-3mm fragments at room temperature, washed with water, and then air-dried in a 50℃ oven for 2 hours before being stored at room temperature. The ground tire fragments (1.0g) were then immersed in a contaminant solution (150μL, 200mg / L 6PPDQ, dissolved in acetonitrile) and subjected to a rotating agitation (150rpm, 35℃) for 24 hours to ensure uniform adsorption. The mixture was then sieved (60 mesh) and stored frozen at -20℃.

[0037] Degradation experimental apparatus

[0038] The test waxworms (approximately 250 mg) were exposed to tire debris or "tire debris + 6 PPDQ". After 48 hours of feeding, the worms were removed and placed in a clean culture box for 12 hours. The worm feces were collected, and the worms were then returned to the degradation system to continue tire degradation. The total feeding period was 30 days.

[0039] Methods for assessing tire degradation

[0040] After freeze-drying the collected insect excrement (48 h), the molecular weight, functional groups, chemical composition, and crystallinity were determined by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry, infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction, respectively. The results were compared with the properties of the tires before consumption to accurately assess the degradation capacity of waxworms and intestinal microorganisms on tires, as well as the impact of 6PPDQ on the tire degradation process.

[0041] Assessment Methods for the Growth and Development of Waxworms during the Process of Edible Tires and "Tire + 6PPDQ"

[0042] The weight, pupation, and mortality of the test insects were measured every two days. The effects of tires and 6PPDQ on insect growth and development were examined by comparing the starvation control and the feeding (beeswax, the basic food for waxworms) control.

[0043] Degradation of wax beetle tires

[0044] By comparing the time-of-flight mass spectra of the front and rear tire matrix-assisted laser desorption / ionization mass spectra (... Figure 2It can be seen that repeating units (310 g / mol) are generated in the molecular weight range of 1200-3000 g / mol, and there are similar molecular weight structures among the repeating units, such as alkynyl groups (26 g / mol). This result indicates that after waxworms consume tires, they can break the polymer chains of the tires and produce short-chain structures with a molecular weight of approximately 2800, which are composed of repeating units of 310 g / mol. Secondly, X-ray diffraction results show ( Figure 3 A) After treatment with waxworms, the crystallinity of the tires increased by 9.1%, further indicating that waxworms broke the cross-linking structure between some polymer chains.

[0045] Changes in chemical composition and functional groups provide additional evidence for tire depolymerization. This is illustrated in the thermogravimetric / thermogravimetric differential diagram (…). Figure 4 The raw materials exhibited weight loss between 300–468℃ and showed two decomposition temperatures. However, in the collected insect excrement, the decomposition temperature range broadened to 130–430℃, with three decomposition temperatures observed. Furthermore, the decomposition temperatures of the excrement did not overlap with those of the raw materials, indicating a complete change in the chemical composition after treatment with the wax insects. Regarding the differences in functional groups, Fourier transform infrared spectroscopy (FTIR) was used. Figure 5 This indicates that after feeding by waxworms, the following changes occurred in both tires and “tire + 6PPDQ”: ① stronger hydroxyl stretching vibrations (3700–3000 cm⁻¹). -1 ); ② New C=C stretching vibration peak ( Figure 5 The light gray shaded portion; olefin: 1680–1620 cm -1 Aromatics: 1650–1450 cm -1 ); ③ The original fingerprint area (dark gray shaded area) is approximately 793, 739, and 697 cm. -1 The peak at 800–670 cm⁻¹ disappears. The newly appearing C=C stretching vibration peak may be due to the aryl ring skeleton vibration caused by the change in the aryl substitution position. -1 The three peaks that disappeared at the point are likely due to the methylene group (n=2, approximately 739 cm⁻¹). -1 The fracture of the aromatic ring and the side groups (meta-substitution, 810–750, 710–690 cm) -1 The breakage of the peaks is the cause. These newly appearing and disappearing peaks indicate that the main changes occur on the aromatic rings of the tire polymer chain.

[0046] The degradation and transformation of tires and 6PPDQ in "tire + 6PPDQ" by waxworms

[0047] Quantitative analysis of 6PPDQ adsorbed on tires before and after consumption by waxworms showed that the waxworms degraded approximately 62.5% (1.25 × 10⁻⁶). -6The degradation effect on 6PPDQ (g-6PPDQ / g-tire) is significant. Therefore, it can be inferred that waxworms can completely degrade the original 6PPDQ (4.5 × 10⁻⁶ PPDQ) on the tire. -7 g-6PPDQ / g-tires).

[0048] By comparing the time-of-flight mass spectra of the front and rear tire matrix-assisted laser desorption / ionization mass spectra (... Figure 2 It can be seen that under high concentrations of 6PPDQ stress, waxworms almost lost their ability to depolymerize tires, specifically manifested in the disappearance of repeating units at 1200-3000 g / mol. Secondly, X-ray diffraction results show ( Figure 3 B) After treatment with waxworms, the crystallinity of "tire + 6PPDQ" increased by 5.9%, while the increase in crystallinity was reduced by 3.2% compared to the group that only ate tires. This indicates that the waxworms' ability to depolymerize tire polymer chains decreased under high concentration of 6PPDQ stress.

[0049] Secondly, the modification effect of wax beetles on tire functional groups is slight under high 6PPDQ stress. The thermogravimetric / thermogravimetric differential diagrams of the tire and "tire + 6PPDQ" almost overlap. Figure 4 The infrared spectra also largely overlap. Figure 5 B), the difference lies in the 6PPDQ stress at 1231cm. -1 and 1112cm -1 Asymmetric and symmetric stretching vibrations of CO were observed, indicating the formation of ester bonds.

[0050] Growth and development of waxworms during the process of edible tires and "tire + 6PPDQ".

[0051] During the 30-day experimental period, waxworms continuously fed on tires and "tire + 6 PPDQ", but the feeding rate was faster in the first 10 days. Figure 6 A). Waxworms consumed significantly more "tire + 6PPDQ" than tires (p = 0.045). In contrast, 6PPDQ had a significantly lower negative impact on waxworms (mortality rate and weight loss). Figure 6 There were no significant differences between the experimental and control groups for B and 6C. Secondly, the "tire + 6PPDQ" group had the lowest mortality rate. Pupation is the process by which insects complete their metamorphosis life cycle, and this process is accelerated during energy shortages. Feeding on tires significantly increased the pupation rate of wax beetles. Figure 6 D) indicates that tires promote pupation of waxworms, but 6PPDQ inhibits this process.

[0052] Waxworms consumed more "tire + 6PPDQ" than tires, and did not experience more harmful effects on growth and development compared to the tire-fed group.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for degrading tire and tire antioxidant contaminants using waxworms, characterized in that, The specific steps include: Step 1: Constructing a degradation system; Step 2: Collect waxworm feces from the container during the test period, analyze the degree of polymerization, functional groups, crystallinity and chemical composition of the polymer residues in the feces, evaluate the degradation effect, and measure the residual 6PPDQ in the feces to evaluate the removal effect of waxworms on the tire surface when adsorbed.

2. The method for degrading tire and tire antioxidant contaminants using waxworms according to claim 1, characterized in that, The specific process for constructing the degradation system in step 1 is as follows: Step 101: Set multiple vent holes at the top of the culture container to ensure air circulation and exchange between the inside and outside of the container; Step 102: Place the crushed tire debris, which has absorbed 6 PPDQ, into an incubation container; Step 103: Add waxworms into the culture container.

3. The method for degrading tire and tire antioxidant contaminants using waxworms according to claim 2, characterized in that, In step 102, the length of the tire debris is 2mm to 3mm.

4. The method for degrading tire and tire antioxidant contaminants using waxworms according to claim 2, characterized in that, In step 103, the density of waxworms introduced into the culture container is 50 worms / liter.

5. The method for degrading tire and tire antioxidant contaminants using waxworms according to claim 1, characterized in that, The experimental period in step 2 is 30 days.

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