Device and method for measuring formaldehyde absorbed by horticultural plant

Abstract

The invention discloses a device and a method for measuring formaldehyde absorbed by horticultural plants. The device comprises a sealing box, an LED plant lamp, a circulating fan, a formaldehyde volatilization table, a formaldehyde measuring instrument, a carbon dioxide measuring instrument, carbon dioxide supply equipment and an auxiliary measuring instrument. The device can support complex experimental condition simulation, can simulate VOCs pollution scenes, provides a standard process for screening and purifying plants, and sequentially performs formaldehyde absorption capacity test, formaldehyde tolerance test and environmental influence test, the three-stage test can screen and efficiently purify plants, and dynamic monitoring is realized by combining a formaldehyde measuring instrument and a carbon dioxide measuring instrument. The test precision is ensured, and a complete evaluation system from a laboratory to engineering application is conveniently established by quantifying the formaldehyde absorption rate, tolerance and environmental influence of the plant.

Description

Technical Field

[0001] This invention relates to the field of purification measurement technology, specifically to a device and method for measuring formaldehyde absorption by horticultural plants. Background Technology

[0002] In enclosed environments, volatile organic pollutants, including formaldehyde, toluene, and inorganic harmful gases (CO, NH3, etc.), mainly originate from building materials, equipment, and human metabolism. Formaldehyde, a typical VOC, can cause retinal damage, neurological dysfunction, and even increase the risk of cancer with long-term exposure. Prolonged exposure to trace amounts of these harmful gases can seriously endanger human health.

[0003] Existing research shows that horticultural plants can effectively absorb and utilize formaldehyde. Their purification mechanism, purification capacity, tolerance, and influencing factors are as follows: (1) Purification mechanism: After formaldehyde is absorbed by the stomata of leaves, it is metabolized and degraded through the Calvin cycle, C1 metabolism, and other pathways. At the same time, rhizosphere microorganisms decompose the formaldehyde adsorbed by the soil. (2) Purification capacity: Chrysanthemum, Boston fern, and other plants show outstanding performance. For example, ivy can absorb formaldehyde at 13.3m. 3 19.378 mg of VOCs can be absorbed in the space in 24 hours. Plant combinations (such as dragon blood tree and variegated daphne) have a good purification effect on TVOC; (3) Tolerance: It is necessary to comprehensively evaluate chlorophyll content, antioxidant enzyme activity (CAT, POD) and cell ultrastructure (stomatal aperture, chloroplast morphology); (4) Influencing factors: leaf area, light intensity and temperature significantly affect purification efficiency.

[0004] The measuring devices in related technologies can only assess the purification capacity of plants, but lack systematic quantitative analysis of tolerance and environmental factors (such as CO2 concentration and light intensity gradient), making it difficult to meet the needs of precise control in closed environments. This invention proposes a new solution to the above problems. Summary of the Invention

[0005] In order to overcome at least one of the above-mentioned disadvantages, the present invention provides a device and method for measuring formaldehyde absorption by horticultural plants.

[0006] The objective of this invention can be achieved by adopting the following technical solution:

[0007] A first aspect of this application provides a device for measuring formaldehyde absorption by horticultural plants, comprising:

[0008] A sealed box, the sealed box being made of a light-transmitting material, the sealed box comprising a box body and a box door, the box body and the box door being able to enclose and form a sealed space, the sealed box being provided with an air inlet and an air outlet;

[0009] LED plant lights are installed above the outside of the sealed box to provide light to the horticultural plants inside the sealed space through the sealed box;

[0010] A circulating fan, wherein the circulating fan is disposed within the sealed enclosure;

[0011] A formaldehyde evaporation table is placed in front of the circulating fan and is used to place a petri dish containing formaldehyde solution. The circulating fan is used to evenly distribute the formaldehyde gas in the sealed box.

[0012] A formaldehyde measuring instrument, wherein the formaldehyde measuring instrument monitors the formaldehyde concentration parameter in the sealed box in real time through a first gas measuring circuit, the first gas measuring circuit being connected to the air inlet and the air outlet respectively;

[0013] A carbon dioxide measuring instrument, wherein the carbon dioxide measuring instrument monitors the carbon dioxide concentration parameter in the sealed box in real time through a second gas measuring circuit, the second gas measuring circuit being connected to the inlet and the outlet respectively;

[0014] A carbon dioxide supply device, wherein the carbon dioxide supply device is used to inject carbon dioxide into the sealed box and adjust the carbon dioxide concentration inside the sealed box;

[0015] Auxiliary measuring instruments used to measure physiological indicators of horticultural plants.

[0016] In one possible implementation, the horticultural plants include at least one of chrysanthemum, Nephrolepis cordifolia, Rhapis excelsa, Anthurium andraeanum, Aloe vera, and Spathiphyllum.

[0017] In one possible implementation, the formaldehyde absorption measuring device for horticultural plants further includes:

[0018] A temperature and humidity sensor is installed inside the sealed box to detect the temperature and humidity inside the sealed box.

[0019] A formaldehyde measuring instrument is installed outside the sealed box. It draws gas from the sealed box through a first gas measuring circuit to measure the formaldehyde concentration. After the measurement is completed, the gas is returned to the sealed box.

[0020] A carbon dioxide measuring instrument is located outside the sealed box. The instrument draws gas from inside the sealed box through a second gas measuring circuit to measure the carbon dioxide concentration. After the measurement is completed, the gas is returned to the sealed box.

[0021] In one possible implementation, the first gas measurement circuit includes a first gas outlet and a first gas inlet. One end of the first gas outlet is connected to the gas outlet, and the other end of the first gas outlet is connected to the input terminal of the formaldehyde measuring instrument. One end of the first gas inlet is connected to the output terminal of the formaldehyde measuring instrument, and the other end of the first gas inlet is connected to the gas inlet.

[0022] The second gas measurement circuit includes a second gas outlet and a second gas inlet. One end of the second gas outlet is connected to the gas outlet, and the other end of the second gas outlet is connected to the input terminal of the carbon dioxide meter. One end of the second gas inlet is connected to the output terminal of the carbon dioxide meter, and the other end of the second gas inlet is connected to the gas inlet.

[0023] In one possible implementation, the carbon dioxide supply device includes:

[0024] Carbon dioxide cylinders are used to store carbon dioxide gas.

[0025] A pipeline, one end of which is connected to the gas cylinder and the other end of which is connected to the air inlet, through which the gas cylinder delivers carbon dioxide gas into the sealed box;

[0026] A pressure reducing valve is installed on the pipeline to regulate the pressure of carbon dioxide gas flow within the pipeline;

[0027] A mass flow meter is installed on the pipeline to measure the mass flow rate of carbon dioxide gas flow within the pipeline.

[0028] In one possible implementation, the auxiliary measuring instrument includes:

[0029] Chlorophyll meter, used to measure the chlorophyll content of leaves of horticultural plants;

[0030] A handheld chlorophyll fluorometer is used to process the fluorescence properties of horticultural plant leaves.

[0031] A leaf area meter is used to measure the area of ​​leaves in horticultural plants.

[0032] A projection electron microscope is used to observe ultrastructural changes in horticultural plant cells.

[0033] Scanning electron microscope (SEM) is used to observe the surface structure of leaves in horticultural plants.

[0034] An electronic balance for weighing the biomass of horticultural plants, the biomass including fresh weight and / or dry weight;

[0035] A spectrophotometer is used for colorimetric determination of malondialdehyde (MDA), protein, and enzyme content in the leaves of horticultural plants.

[0036] An electric thermostatic drying oven is used to dry horticultural plants.

[0037] A second aspect of this application provides a method for measuring formaldehyde absorption by horticultural plants, applied to the formaldehyde absorption measuring device for horticultural plants described in any one of the first aspects, the method comprising the following steps:

[0038] A variety of test plants were selected to test their formaldehyde absorption capacity.

[0039] After the formaldehyde absorption capacity test, select at least three horticultural plants with strong formaldehyde absorption capacity to conduct a plant formaldehyde absorption tolerance test.

[0040] After the formaldehyde tolerance test, horticultural plants with strong formaldehyde tolerance were selected to test the impact of environmental factors on the absorption of formaldehyde by horticultural plants.

[0041] In one possible implementation, the formaldehyde absorption capacity testing steps include:

[0042] Multiple plants to be tested were tested in batches. Each test used multiple sealed boxes as parallel groups for formaldehyde fumigation and one as a blank control group. Multiple pots of the same type and with the same growth status were placed in each sealed box.

[0043] Before the test, the plant leaves were sprayed with pure water to eliminate the influence of microorganisms, and the culture pot was wrapped with black plastic film to isolate the adsorption of the substrate.

[0044] The environmental conditions inside the sealed chamber were adjusted to a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m. -2 s -1 Humidity 70%, temperature 25±1℃, and preset light cycle time;

[0045] Add 40 μL of a 10.2 mg / mL formaldehyde standard solution to the formaldehyde volatilization platform to bring the theoretical formaldehyde concentration inside the sealed box to 5 mg / mL. -3 ;

[0046] During fumigation, formaldehyde concentration and CO2 concentration were measured at regular intervals. After the fumigation, the leaf area, biomass, chlorophyll, and malondialdehyde content of the plants were measured to screen out the plants with the best formaldehyde absorption capacity.

[0047] In one possible implementation, the formaldehyde tolerance test step includes:

[0048] Several plants with the best formaldehyde absorption capacity were selected and cultivated using granular soil substrate;

[0049] The selected plants were tested in batches. Multiple sealed boxes were used for each test, with blank control and multiple different formaldehyde concentration gradients set up. The concentration was controlled by precisely adding 10.2 mg / mL formaldehyde standard solution, and an equal amount of solution was added after a period of time.

[0050] Maintain a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m⁻² inside the sealed chamber. -2 s -1 Temperature 25±1℃, humidity 70%, preset photoperiod time;

[0051] During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain stable concentrations.

[0052] After the test, the plant tolerance was comprehensively evaluated by appearance changes, physiological indicators and microstructure, and the best plants were selected.

[0053] In one possible implementation, testing the impact of environmental factors on formaldehyde absorption by horticultural plants includes:

[0054] Several plants that had passed tolerance tests were selected and cultured in a granular soil substrate. Multiple plants were placed in each sealed box, and a black plastic film was used to isolate the substrate from adsorption.

[0055] 0.48 mL of a 10.2 mg / mL formaldehyde standard solution was simultaneously injected into multiple sealed boxes. A CO2 concentration gradient was set, and the light intensity was kept constant at 200 ± 50 μmol·m⁻² during the first stage. -2 ·s -1 ;

[0056] During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain the set concentrations.

[0057] The second stage will increase the light intensity to 400±50 μmol·m -2 ·s -1 Repeat the fumigation process.

[0058] The beneficial technical effects of this invention are as follows: According to this disclosure, the horticultural plant formaldehyde absorption measuring device includes a sealed box, LED plant lights, a circulating fan, a formaldehyde volatilization platform, a formaldehyde measuring instrument, a carbon dioxide measuring instrument, a carbon dioxide supply device, and auxiliary measuring instruments. It supports the simulation of complex experimental conditions and can simulate VOCs pollution scenarios, providing a standard process for screening purification plants. The measurement method can screen out the plants with the best formaldehyde purification efficiency through a three-stage test. The three-stage test includes absorption capacity, tolerance, and environmental impact. Combined with the formaldehyde measuring instrument and the carbon dioxide measuring instrument, dynamic monitoring is achieved to ensure test accuracy. By quantifying the plant's formaldehyde absorption rate, tolerance, and environmental impact, a complete evaluation system from laboratory to engineering application is easily established. Attached Figure Description

[0059] The following are given by way of example and without limitation in the accompanying drawings:

[0060] Figure 1 A schematic diagram of the overall structure of the measuring device according to an embodiment of this application is shown;

[0061] Figure 2 A flowchart of a method for measuring formaldehyde absorption by horticultural plants according to an embodiment of this application is shown;

[0062] Figure 3 The graph showing the formaldehyde concentration variation inside the box containing six plants, according to an embodiment of this application, is shown.

[0063] Figure 4 The graph shows the formaldehyde absorption rate of six plants;

[0064] Figure 5 The graphs show the formaldehyde absorption rates of *Nephrolepis cordifolia*, *Chrysanthemum morifolium*, and *Bambusa palmatum* at different formaldehyde concentrations.

[0065] Figure 6 The diagram shows the stomatal distribution of chrysanthemum leaves treated with different concentrations of formaldehyde.

[0066] Figure 7 The stomatal distribution of Nephrolepis cordifolia leaves treated with different concentrations of formaldehyde is shown.

[0067] Figure 8 The stomatal distribution of bamboo leaves treated with different concentrations of formaldehyde is shown.

[0068] Figure 9 The cell structure diagrams of chrysanthemum leaves treated with different concentrations of formaldehyde are shown.

[0069] Figure 10 The cell structure diagrams of Nephrolepis leaf leaves treated with different concentrations of formaldehyde are shown.

[0070] Figure 11 The cell structure diagrams of bamboo palm leaves treated with different concentrations of formaldehyde are shown.

[0071] Figure 12 The formaldehyde absorption curves of Nephrolepis cordifolia at a carbon dioxide concentration of 500 ppm under different light intensities are shown.

[0072] Figure 13 The formaldehyde absorption curves of Nephrolepis cordifolia at different light intensities and carbon dioxide concentrations of 1000 ppm are shown.

[0073] Figure 14 The formaldehyde absorption curves of Nephrolepis cordifolia at different light intensities and carbon dioxide concentrations of 1500 ppm are shown.

[0074] Figure 15 The formaldehyde absorption curves of Nephrolepis cordifolia at different light intensities and carbon dioxide concentrations of 2000 ppm are shown.

[0075] Figure 16 The formaldehyde absorption curves of chrysanthemums with different light intensities and carbon dioxide concentrations of 500 ppm are shown.

[0076] Figure 17 The formaldehyde absorption curves of chrysanthemums with different light intensities and carbon dioxide concentrations of 1000 ppm are shown.

[0077] Figure 18 The formaldehyde absorption curves of chrysanthemums with different light intensities and carbon dioxide concentrations of 1500 ppm are shown.

[0078] Figure 19 The formaldehyde absorption curves of chrysanthemums under different light intensities and carbon dioxide concentrations of 2000 ppm are shown.

[0079] Figure 20 It shows 200 μmol·m -2 s -1 Graph showing the formaldehyde absorption rate of chrysanthemums under different carbon dioxide concentrations under illumination;

[0080] Figure 21 It shows 400 μmol·m -2 s -1 Graph showing the formaldehyde absorption rate of chrysanthemums under different carbon dioxide concentrations under illumination;

[0081] Figure 22 It shows 200 μmol·m -2 s -1 Graph showing the formaldehyde absorption rate of Nephrolepis cordifolia under different carbon dioxide concentrations under illumination;

[0082] Figure 23 It shows 400 μmol·m -2 s -1 Graph showing the formaldehyde absorption rate of Nephrolepis cordifolia under different carbon dioxide concentrations under illumination.

[0083] In the diagram: 1. Sealed box; 2. LED plant light; 3. Horticultural plants; 4. Circulating fan; 5. Formaldehyde volatilization platform; 6. Petri dish; 7. Temperature and humidity sensor; 8. Handle; 9. Locking buckle; 10. Air outlet; 11. Air inlet; 12. Shut-off valve; 13. Formaldehyde meter; 14. Carbon dioxide meter; 15. Carbon dioxide cylinder; 16. Pressure reducing valve; 17. Mass flow meter; 18. Auxiliary measuring instruments; 19. Chlorophyll meter; 20. Handheld chlorophyll fluorometer; 21. Leaf area meter; 22. Transmission electron microscope; 23. Scanning electron microscope; 24. Electronic balance; 25. Spectrophotometer; 26. Electric thermostatic drying oven. Detailed Implementation

[0084] In the following detailed disclosure, these embodiments are fully described with reference to the accompanying drawings. In order to enable those skilled in the art to understand and clarify the technical solution of the present invention more clearly, the embodiments described below are not limited thereto. The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0085] The first aspect of this application, as Figure 1 As shown, a formaldehyde absorption measuring device for horticultural plants is provided, including a sealed box 1, an LED plant light 2, a circulating fan 4, a formaldehyde volatilization platform 5, a formaldehyde measuring instrument 13, a carbon dioxide measuring instrument 14, a carbon dioxide supply device, and auxiliary measuring instruments 18. The sealed box 1 is made of a light-transmitting material and includes a box body and a door, which can be closed to form a sealed space. The sealed box 1 is provided with an air inlet 11 and an air outlet 10. The LED plant light 2 is located above the outside of the sealed box 1 to provide light to the horticultural plants 3 inside the sealed space through the sealed box 1. The circulating fan 4 is located inside the sealed box 1, and the formaldehyde volatilization platform 5 is located in front of the circulating fan 4. A petri dish 6 containing formaldehyde solution is used to place the petri dish 6. A circulating fan 4 is used to evenly distribute the formaldehyde gas in the sealed box 1. A formaldehyde measuring instrument 13 monitors the formaldehyde concentration parameter in the sealed box 1 in real time through a first gas measuring circuit, which is connected to the air inlet 11 and the air outlet 10 respectively. A carbon dioxide measuring instrument 14 monitors the carbon dioxide concentration parameter in the sealed box 1 in real time through a second gas measuring circuit, which is connected to the air inlet 11 and the air outlet 10 respectively. A carbon dioxide supply device is used to inject carbon dioxide into the sealed box 1 and adjust the carbon dioxide concentration in the sealed box 1. An auxiliary measuring instrument 18 is used to measure the physiological indicators of the horticultural plants 3.

[0086] The horticultural plant formaldehyde absorption measuring device provided in this embodiment includes a sealed box 1, an LED plant light 2, a circulating fan 4, a formaldehyde volatilization platform 5, a formaldehyde measuring instrument 13, a carbon dioxide measuring instrument 14, a carbon dioxide supply device, and auxiliary measuring instruments 18. It supports the simulation of complex experimental conditions and can simulate VOCs pollution scenarios in closed spaces, providing a standard process for screening and purifying plants.

[0087] The horticultural plant formaldehyde measurement device, through the synergistic action of components such as a sealed box 1, LED plant lights 2, and a circulating fan 4, achieves accurate assessment of plants' formaldehyde absorption capacity. The device simulates a uniform formaldehyde gas environment using a formaldehyde volatilization platform 5 and a circulating fan 4. Combined with real-time monitoring of formaldehyde and carbon dioxide levels by a formaldehyde meter 13 and a carbon dioxide meter 14, it dynamically tracks changes in gas concentration within the box. The LED plant lights 2 provide controllable lighting conditions, the carbon dioxide supply equipment regulates the carbon dioxide level within the box, and the auxiliary measuring instrument 18 records the physiological effects on the plants. The entire system can simulate VOCs pollution scenarios in a confined space, enabling multi-stage testing and screening of highly efficient purification plants.

[0088] The sealed box 1 is made of transparent polycarbonate material and has four support blocks at the bottom. The sealed box 1 includes a box body and a hinged door located at the front of the box body. The door is equipped with a handle 8, a sealing ring, and a locking buckle 9. The door and box body form a sealed structure, enclosing a sealed space for placing garden plants 3. Furthermore, the box body has a light transmittance >93%; its volume can be approximately 80L, with dimensions of 40cm × 40cm × 50cm, or other volumes and sizes can be selected; the leakage rate of the box body measured over 24 hours is <5%.

[0089] The LED plant light 2 is located directly above the outside of the sealed box 1. The LED light shines through the transparent polycarbonate panel at the top of the box, providing illumination for the horticultural plants 3 inside. Furthermore, the LED plant light 2 can be a full-spectrum white LED with a light intensity of 200 μmol·m⁻². -2 s -1 -400 μmol·m -2 s -1 The illumination period is adjustable within the range of 0h-24h.

[0090] The circulating fan 4 can be installed on the rear panel inside the sealed box 1 to rapidly evaporate the formaldehyde solution and circulate the air inside the sealed box 1, keeping the formaldehyde, carbon dioxide, temperature, and humidity in different parts of the air relatively consistent. The formaldehyde evaporation table 5 is located directly in front of the circulating fan 4 and is used to place a container containing formaldehyde solution, i.e., a petri dish 6, to promote the rapid evaporation of formaldehyde into the air inside the sealed box 1 under the airflow of the circulating fan 4.

[0091] The carbon dioxide supply device is located outside the sealed box 1 and is connected to the gas inlet 11 in the gas measurement circuit through a pipeline. It can inject a certain amount of carbon dioxide into the sealed box 1 and can adjust the carbon dioxide concentration in the sealed box 1.

[0092] In one possible implementation, the horticultural plant 3 includes at least one of chrysanthemum, nephrolepis, bamboo palm, anthurium, aloe vera, and peace lily.

[0093] Horticultural plant 3 is placed inside sealed box 1 to measure its formaldehyde absorption. Generally, horticultural plants with strong formaldehyde absorption capacity are selected for plant 3, such as chrysanthemum, nephrolepis, bamboo palm, anthurium, aloe vera, and peace lily, with a plant height slightly lower than the height of sealed box 1. For example, if the height of sealed box 1 is 50cm, the plant height should generally not exceed 45cm.

[0094] In one embodiment, the formaldehyde absorption measuring device for horticultural plants further includes a temperature and humidity sensor 7, a formaldehyde measuring instrument 13, and a carbon dioxide measuring instrument 14. The temperature and humidity sensor 7 is installed inside the sealed box 1 to detect the temperature and humidity inside the sealed box 1. The formaldehyde measuring instrument 13 is installed outside the sealed box 1 and draws gas from the sealed box 1 through a first gas measuring circuit to measure the formaldehyde concentration. After the measurement is completed, the gas is returned to the sealed box 1. The carbon dioxide measuring instrument 14 is installed outside the sealed box 1 and draws gas from the sealed box 1 through a second gas measuring circuit to measure the carbon dioxide concentration. After the measurement is completed, the gas is returned to the sealed box 1.

[0095] Among them, the temperature and humidity sensor 7 is installed on the right side plate inside the sealed box 1 to measure and record the temperature and humidity of the air inside the sealed box 1; the formaldehyde measuring instrument 13 is located outside the sealed box 1, and draws air from the sealed box 1 through the first gas measuring circuit to measure and record the formaldehyde concentration of the gas inside the sealed box 1. After the test is completed, the air is returned to the sealed box 1; the carbon dioxide measuring instrument 14 is located outside the sealed box 1, and draws air from the sealed box 1 through the second gas measuring circuit to measure and record the carbon dioxide concentration of the gas inside the sealed box 1. After the test is completed, the air is returned to the sealed box 1.

[0096] The gas measurement circuit is installed on the left side panel inside the sealed box 1, which has an air inlet 11 and an air outlet 10. The air pump inside the formaldehyde meter 13 draws gas from the sealed box 1 through the air outlet 10 to the formaldehyde meter 13 for formaldehyde composition measurement. After measurement, the gas returns to the sealed box 1 through the air inlet 11. Similarly, the air pump inside the carbon dioxide meter 14 draws gas from the sealed box 1 through the air outlet 10 to the carbon dioxide meter 14 for carbon dioxide composition measurement. After measurement, the gas returns to the sealed box 1 through the air inlet 11.

[0097] The first gas measurement circuit includes a first gas outlet and a first gas inlet. One end of the first gas outlet is connected to the outlet 10, and the other end is connected to the input terminal of the formaldehyde measuring instrument 13. One end of the first gas inlet is connected to the output terminal of the formaldehyde measuring instrument 13, and the other end is connected to the inlet 11. The second gas measurement circuit includes a second gas outlet and a second gas inlet. One end of the second gas outlet is connected to the outlet 10, and the other end is connected to the input terminal of the carbon dioxide measuring instrument 14. One end of the second gas inlet is connected to the output terminal of the carbon dioxide measuring instrument 14, and the other end is connected to the inlet 11.

[0098] Two shut-off valves 12 are installed on the gas measurement circuit connected to the air outlet 10 and the air inlet 11, so that the air inside the sealed box 1 can be kept closed when no measurement is being performed.

[0099] In one possible implementation, the carbon dioxide supply device includes a carbon dioxide cylinder 15, a pipeline, a pressure reducing valve 16, and a mass flow meter 17. The carbon dioxide cylinder 15 is used to store carbon dioxide gas. One end of the pipeline is connected to the cylinder, and the other end is connected to the inlet 11. The cylinder delivers carbon dioxide gas into the sealed box 1 through the pipeline. The pressure reducing valve 16 is installed on the pipeline to regulate the pressure of the carbon dioxide gas flow in the pipeline. The mass flow meter 17 is installed on the pipeline to measure the mass flow rate of the carbon dioxide gas flow in the pipeline.

[0100] In one possible implementation, the auxiliary measuring instrument 18 includes a chlorophyll meter 19, a handheld chlorophyll fluorometer 20, a leaf area meter 21, a transmission electron microscope 22, a scanning electron microscope 23, an electronic balance 24, a spectrophotometer 25, and an electric thermostatic drying oven 26. The chlorophyll meter 19 is used to measure the chlorophyll content of the leaves of the horticultural plant 3. The handheld chlorophyll fluorometer 20 is used to process the fluorescence characteristics of the leaves of the horticultural plant 3. The leaf area meter 21 is used to measure the area of ​​the leaves of the horticultural plant 3. The transmission electron microscope 22 is used to observe the ultrastructural changes of the cells of the horticultural plant 3. The scanning electron microscope 23 is used to observe the surface structure of the leaves of the horticultural plant 3. The electronic balance 24 is used to weigh the biomass of the horticultural plant 3, which includes fresh weight and / or dry weight. The spectrophotometer 25 is used to colorimetrically determine the malondialdehyde content, protein content, and enzyme content of the leaves of the horticultural plant 3. The electric thermostatic drying oven 26 is used to dry the horticultural plant 3.

[0101] Among them, the auxiliary measuring instrument 18 is used to assist in measuring the morphological and physiological parameters of the horticultural plant 3 after it absorbs formaldehyde. The characteristics of the plant itself, such as leaf shape, leaf area size, and stomatal opening and closing status, are important factors affecting the absorption of formaldehyde by the plant. For the same plant, the larger the leaf area, the more harmful gas it absorbs. The expression of enzymes controlled by genes in the plant can improve the plant's purification capacity by regulating genes related to the purification of harmful gases. The purification capacity of the plant can be evaluated by analyzing the expression level of genes that metabolize harmful gases (formaldehyde), so as to assess the absorption capacity of the horticultural plant 3 for formaldehyde and the plant's own tolerance, as well as the influence of different environmental factors on the plant's absorption of formaldehyde.

[0102] This embodiment provides the main technical specifications of a formaldehyde measuring device, as shown in Table 1 below.

[0103]

[0104] Table 1

[0105] The second aspect of this application, as Figure 2 As shown, a method for measuring formaldehyde absorption by horticultural plants is provided, applicable to the formaldehyde absorption measuring device for horticultural plants according to any one of the first aspects. The measurement method includes the following steps:

[0106] A variety of test plants were selected to test their formaldehyde absorption capacity.

[0107] After the formaldehyde absorption capacity test, select at least three horticultural plants with strong formaldehyde absorption capacity to conduct a plant formaldehyde absorption tolerance test.

[0108] After the formaldehyde tolerance test, horticultural plants with strong formaldehyde tolerance were selected to test the impact of environmental factors on the absorption of formaldehyde by horticultural plants.

[0109] The method for measuring formaldehyde absorption by horticultural plants provided in this embodiment can screen out the plants with the best formaldehyde purification efficiency through dynamic monitoring and multi-dimensional evaluation. The three-stage test includes absorption capacity, tolerance, and environmental impact. Dynamic monitoring is achieved by combining formaldehyde measuring instruments and carbon dioxide measuring instruments to ensure test accuracy. By quantifying the formaldehyde absorption rate, tolerance, and environmental impact of plants, a complete evaluation system from laboratory to engineering application is easily established.

[0110] In the formaldehyde absorption capacity test, a variety of candidate plants were first screened. By controlling the initial formaldehyde concentration in a closed environment, the absorption performance of different plants under the same conditions was observed. During the test, changes in formaldehyde concentration were monitored in real time, and plants with significantly better absorption capacity than other varieties were screened out. This stage focused on evaluating the basic purification potential of the plants to provide candidates for subsequent tests.

[0111] In the formaldehyde tolerance test, the tolerance of the initially screened high-efficiency plants to high-concentration formaldehyde environments was assessed. During the test, the formaldehyde concentration was gradually increased, and the physiological effects on the plants (such as the degree of leaf damage and changes in enzyme activity) were observed. Varieties that could maintain stable absorption capacity in highly polluted environments were screened out. This stage verified the adaptability and durability of the plants in practical applications.

[0112] In the environmental factor impact test, for plants with strong tolerance, the effects of environmental variables such as light intensity and carbon dioxide concentration on their formaldehyde absorption efficiency were further studied. During the test, by adjusting the experimental conditions, the performance fluctuations of the plants under different environments were analyzed to determine the optimal growth parameters. This stage provides an environmental adaptation plan for engineering applications, ensuring that the selected plants perform at their best in enclosed spaces.

[0113] Before conducting formaldehyde absorption tests on horticultural plants, leak rate tests and VOCs release tests of the sealed container are performed first. Specific steps include leak rate testing and baseline VOCs value testing. This embodiment provides the specific steps and a set of experimental data, as follows:

[0114] S1. Leakage rate test: The leakage rate of the sealed box was measured by the 24-hour carbon dioxide concentration change method. The initial carbon dioxide concentration was 1925 ppm, and the carbon dioxide concentration after 24 hours was 1868 ppm, with a leakage rate of 3%.

[0115] S2. Basic VOCs value test: Collect 5L of gas inside the sealed box at the beginning of sealing and 5 hours after sealing, and determine the types and contents of VOCs volatilized by the sealed box itself, as shown in Table 2 below.

[0116] gas composition <![CDATA[Base sample / mg·m -3 > <![CDATA[5 h later / mg·m -3 > Acetaldehyde 0.086±0.021 0.203±0.016 methanol 1.599±0.596 3.868±0.952 ethanol 0.591±0.466 0.504±0.066 propionaldehyde 0.381±0.043 0.403±0.025 acetone 0.291±0.080 0.468±0.041 dichloromethane 0.04±0.008 2.939±1.520 2-Butanone 0.406±0.135 0.846±0.256 Ethyl acetate 0.418±0.136 0.877±0.265 Cyclohexane 0.201±0.022 0.257±0.027 benzene 0.003±0.0003 0.057±0.025 Toluene 0.0832±0.0003 0.116±0.010 Ethylbenzene 0.004±0.0003 0.005±0.001 p / m-xylene 0.006±0.0004 0.007±0.001 formaldehyde 0.027±0.009 0.056±0.014 n-Octane 0.691±0.029 0.803±0.029

[0117] Table 2

[0118] The following six horticultural plants can be selected for formaldehyde absorption testing: chrysanthemum, nephrolepis cordifolia, bamboo palm, anthurium, aloe vera, and peace lily, with 24 plants of each plant. Specific information on the selected horticultural plants is provided below.

[0119] Table 3 and Table 4 below.

[0120] variety family and genus Plant height / cm Chlorophyll / SPDA value <![CDATA[Total leaf area / cm 2 > chrysanthemum Asteraceae family, Chrysanthemum genus 15.47±0.21 61.23±1.74 984.38±91.07 Nephrolepis cordifolia Nephrolepis genus, family Nephrolepis 33.47±1.15 33.53±1.04 2995.36±458.28 Peace Lily Spathiphyllum (Araceae family) 40.70±2.46 68.27±0.74 3504.94±141.39 Bamboo palm Palm family, Rhapis genus 30.5±3.48 49.77±2.19 1804.14±167.14 Aloe vera Aloe (family Aphrodisiacaceae) 23.40±1.21 88.50±1.51 1697.47±132.76 Wedding candles Anthurium genus, Araceae family 26.70±1.35 60.60±1.66 2924.72±369.22

[0121] Table 3

[0122]

[0123] Table 4

[0124] In the formaldehyde absorption capacity test, the above six plants were used first for the formaldehyde absorption capacity test; in the formaldehyde tolerance test, after the formaldehyde absorption capacity test was completed, three horticultural plants with strong formaldehyde absorption capacity (such as chrysanthemum, bamboo palm, and nephrolepis) were used for the formaldehyde tolerance test; in the environmental impact formaldehyde absorption test, after the tolerance test was completed, horticultural plants with strong formaldehyde tolerance (such as chrysanthemum and nephrolepis) were used for the impact test on the formaldehyde absorption of horticultural plants.

[0125] Horticultural plants were uniformly cultured using granular soil substrate with a particle size of 0.3–2 mm and a pH value of 5.51. Each culture pot was filled with approximately 900 mL of substrate. The dimensions of the culture pot were 15 cm in top diameter, 10 cm in bottom diameter, and 14 cm in height. Two plants were planted in each pot. After the initial watering of each plant was 200 mL, the soil moisture content was 27% (by volume). The plants were then acclimatized for 7 days in a constant temperature and humidity incubator (25℃, 70% RH).

[0126] For formaldehyde measurement, four identical sealed boxes were used, with three identical potted plants placed in each box, and two plants in each pot.

[0127] In one possible implementation, the formaldehyde absorption capacity testing steps include:

[0128] Multiple plants to be tested were tested in batches. Each test used multiple sealed boxes as parallel groups for formaldehyde fumigation and one as a blank control group. Multiple pots of the same type and with the same growth status were placed in each sealed box.

[0129] Before the test, the plant leaves were sprayed with pure water to eliminate the influence of microorganisms, and the culture pot was wrapped with black plastic film to isolate the adsorption of the substrate.

[0130] The environmental conditions inside the sealed chamber were adjusted to a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m. -2 s -1 Humidity 70%, temperature 25±1℃, and preset light cycle time;

[0131] Add 40 μL of a 10.2 mg / mL formaldehyde standard solution to the formaldehyde volatilization platform to bring the theoretical formaldehyde concentration inside the sealed box to 5 mg / mL. -3 ;

[0132] During fumigation, formaldehyde concentration and CO2 concentration were measured at regular intervals. After the fumigation, the leaf area, biomass, chlorophyll, and malondialdehyde content of the plants were measured to screen out the plants with the best formaldehyde absorption capacity.

[0133] This embodiment provides specific steps and experimental data for formaldehyde absorption capacity testing, as follows: Six types of plants were subjected to formaldehyde fumigation tests in six batches. In each test, four sealed boxes contained plants of the same species and with consistent growth conditions. Three of the sealed boxes contained plants that were mutually purified with formaldehyde (5 mg / m³). -3 The parallel groups treated with fumigation were used, and the remaining plants in a sealed box were considered as those not treated with formaldehyde (0 mg / m³). -3 The blank control group was used; before the test, the plant leaves were sprayed with pure water for 40 seconds to eliminate the influence of microorganisms on the leaves on the test. The culture pots were wrapped with black plastic film, sealing the substrate and exposing only the above-ground parts of the plants to eliminate the influence of formaldehyde adsorbed by the substrate on the test. After treatment, the three pots of plants were placed in a sealed box; the carbon dioxide concentration in the sealed box was maintained at 500±100ppm and the light intensity was 200μmol·m -2 ·s -1 The humidity was 70%, the temperature was 25±1℃, and the photoperiod was 5 hours. 40 μL of a 10.2 mg / mL formaldehyde standard solution was dropped into a petri dish on the formaldehyde evaporation platform near the circulating fan inside the sealed chamber. The chamber door was immediately closed, and the chamber was kept sealed. After approximately 30 minutes, the formaldehyde completely evaporated. Theoretically, the concentration in an 80L sealed chamber would be 5 mg / mL. -3 After adding a certain volume of formaldehyde standard solution to the empty sealed box, due to the small amount of formaldehyde sampled, some formaldehyde may remain on the pipette tip, and there was a slight leakage from the sealed box. The actual concentration of formaldehyde after evaporation was 4.20 ± 0.39 mg·m³. -3 Approximately the design concentration (5 mg·m³) -3 The formaldehyde concentration was 84% ​​of the total formaldehyde concentration. The fumigation time was 5 hours. After the door was closed, the formaldehyde concentration in the sealed box was measured every 15 minutes and the carbon dioxide concentration was measured every hour. After the fumigation was completed, the plants were taken out and the leaf area, biomass, chlorophyll, malondialdehyde content and other indicators were measured. Three plants with better formaldehyde absorption capacity (such as chrysanthemum, bamboo palm and nephrolepis) were initially screened for the next formaldehyde tolerance test.

[0134] In one possible implementation, the formaldehyde tolerance test step includes:

[0135] Several plants with the best formaldehyde absorption capacity were selected and cultivated using granular soil substrate;

[0136] The selected plants were tested in batches. Multiple sealed boxes were used for each test, with blank control and multiple different formaldehyde concentration gradients set up. The concentration was controlled by precisely adding 10.2 mg / mL formaldehyde standard solution, and an equal amount of solution was added after a period of time.

[0137] Maintain a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m⁻² inside the sealed chamber. -2 s -1 Temperature 25±1℃, humidity 70%, preset photoperiod time;

[0138] During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain stable concentrations.

[0139] After the test, the plant tolerance was comprehensively evaluated by appearance changes, physiological indicators and microstructure, and the best plants were selected.

[0140] This embodiment provides specific steps and experimental data for a formaldehyde tolerance test, as follows: Pre-test treatment is the same as for the formaldehyde absorption capacity test. Three plants with excellent formaldehyde absorption capacity (chrysanthemum, bamboo palm, and nephrolepis cordifolia) are selected and tested in three batches. Each test involves placing the same type of plant in four sealed boxes. Three different formaldehyde concentrations (15, 30, and 60 mg / m³) are set for the test. -3 The test group consisted of one without formaldehyde (0 mg / m³). -3 A blank control was provided; the three treatment groups were named Treatment 1, Treatment 2, and Treatment 3, respectively. Treatment 1 involved adding 0.12 mL of a 10.2 mg / mL formaldehyde standard solution (absolute amount 1.2 mg, formaldehyde concentration in the sealed chamber 15 mg / mL) to the sealed chamber. -3 ); 0.24 mL of a formaldehyde standard solution with a concentration of 10.2 mg / mL (absolute amount 2.4 mg, formaldehyde concentration in the sealed chamber 30 mg / mL) was added to the sealed chamber for treatment 2. -3 ); 0.48 mL of a formaldehyde standard solution with a concentration of 10.2 mg / mL (absolute amount 4.8 mg, formaldehyde concentration in the sealed chamber 60 mg / mL) was added to the sealed chamber for treatment 3. -3 Four hours later, formaldehyde standard solution was added to each test group. The amount of formaldehyde used in each sealed chamber was the same as the initial addition, and other environmental conditions were the same as those for the formaldehyde absorption capacity test. The carbon dioxide concentration in the sealed chamber was maintained at 500±100ppm, and the light intensity was maintained at 200±50μmol·m. -2 ·s -1 The humidity was 70%, the temperature was 25±1℃, and the photoperiod was 8 hours. Formaldehyde fumigation lasted for 8 hours, and the formaldehyde and carbon dioxide concentrations were measured every hour for a total of 8 times. Carbon dioxide was replenished in a timely manner through the carbon dioxide supply equipment. After the fumigation, the appearance, physiological indicators, and microstructural changes (changes in leaf stomata and differences in cell structure) of the three plants were compared after fumigation with different concentrations of formaldehyde. Two plants with better formaldehyde tolerance (such as chrysanthemum and Nephrolepis cordifolia) were selected from the three plants for further testing.

[0141] In one possible implementation, testing the impact of environmental factors on formaldehyde absorption by horticultural plants includes:

[0142] Several plants that had passed tolerance tests were selected and cultured in a granular soil substrate. Multiple plants were placed in each sealed box, and a black plastic film was used to isolate the substrate from adsorption.

[0143] 0.48 mL of a 10.2 mg / mL formaldehyde standard solution was simultaneously injected into multiple sealed boxes. A CO2 concentration gradient was set, and the light intensity was kept constant at 200 ± 50 μmol·m⁻² during the first stage. -2 ·s -1 ;

[0144] During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain the set concentrations.

[0145] The second stage will increase the light intensity to 400±50 μmol·m -2 ·s -1 Repeat the fumigation process.

[0146] This embodiment provides specific steps and experimental data for testing the influence of environmental factors on formaldehyde absorption by horticultural plants, as follows: Pre-test treatment is the same as for the formaldehyde absorption capacity test. Two plants with excellent formaldehyde tolerance (such as chrysanthemum and Nephrolepis cordifolia) are selected and tested in two batches to promote formaldehyde absorption. In each test, the same type of plant is placed in four sealed boxes, and the same concentration of formaldehyde is added to all four boxes. A 0.48 mL formaldehyde standard solution with a concentration of 10.2 mg / mL (absolute amount 4.8 mg, formaldehyde concentration in the sealed boxes 60 mg / mL) is used. -3 Fumigation of two plants (chrysanthemum and Nephrolepis cordifolia) for 5 hours; carbon dioxide concentrations in four sealed chambers controlled at 500, 1000, 1500, and 2000 ppm respectively; two light intensities (200 and 400 μmol·m⁻²) were set. - 2 s -1 The light intensity in the four sealed chambers was initially controlled at 200±50 μmol·m⁻². -2 s -1 During the fumigation process, formaldehyde and carbon dioxide concentrations were measured every hour, and carbon dioxide was replenished in each sealed chamber as needed. After fumigation, the light intensity was increased to 400±50 μmol·m⁻². -2 s -1 Under the same conditions, repeat the fumigation process.

[0147] This embodiment provides test indicators and measurement methods, as detailed below:

[0148] Formaldehyde concentration and absorption rate were measured as follows: After formaldehyde was added to the sealed chamber, a portable formaldehyde analyzer was connected to the gas line and the formaldehyde concentration inside the chamber was measured at regular intervals. The stable value obtained after 5 minutes of measurement was recorded each time. The formula for calculating the formaldehyde absorption rate is as follows:

[0149] V = HCHO / A 总 / t

[0150] In the formula: V—formaldehyde absorption rate per unit leaf area of ​​the plant in the sealed box (mg·m²) -2 ·h -1 ); HCHO—the amount of formaldehyde absorbed by the plant within a certain period of time (mg); Atotal—the total leaf area of ​​the plant in the sealed box (m2). 2 ); t—measurement time interval (h).

[0151]

[0152] Where: a1, a2—formaldehyde concentrations (ppm) measured in two consecutive measurements; V 箱 —Sealed box volume (m³) 3 T—Thermodynamic temperature of the gas at room temperature (K); R—Gas constant; P—Gas pressure (Pa); n—Amount of formaldehyde (mol).

[0153] Among them, plant chlorophyll content: The relative chlorophyll content in the middle of plant leaves, i.e., the SPAD value, is detected using a convenient detector.

[0154] Chlorophyll fluorescence was measured using a chlorophyll fluorometer and a dark adaptation clip. The leaves were held in the dark for 20 minutes before measurement, with one leaf measured per pot. The maximum photochemical efficiency of Photosystem II (PSII) was calculated using the following formula:

[0155]

[0156] Where: Fo—minimum fluorescence intensity; Fm—maximum fluorescence after dark adaptation and irradiation with saturated pulsed light; Fv—maximum variable fluorescence intensity.

[0157] Among them, leaf area: the total leaf area A of all plant leaves was measured using a leaf area meter; microstructure: the ultrastructure of mesophyll cells was characterized using SEM and TEM; plant biomass: after harvest, the plants were placed in an oven at 105℃ for half an hour to kill the green, and then dried at 75℃ until constant weight. After cooling, the dry weight of the plants was obtained by weighing with a balance of 0.1%.

[0158] Take 1g of harvested plant leaves and, under ice bath conditions, add 9mL of 0.1mol·L⁻¹ solution to a mortar. -1Phosphate buffer (pH = 7.3) was used to thoroughly grind the plant leaves to prepare a 10% (w / v) tissue homogenate, which was then incubated at 3500 rpm at 4°C. -1 After centrifugation for 10 min, the supernatant was collected to determine total protein, malondialdehyde, and related enzyme activities. The relevant assays were performed using a kit, and the specific calculation methods are as follows:

[0159] Total protein is calculated using the following formula:

[0160]

[0161] Where: Cpr—protein concentration of the sample to be tested; A—absorbance value; C 标准 — Protein standard solution concentration; N — Dilution factor of sample before testing.

[0162] Malondialdehyde is calculated using the following formula:

[0163]

[0164] Where: Cpr—protein concentration of the sample to be tested; OD—absorbance value; D 标准 —MDA standard solution concentration.

[0165] Catalase is calculated using the following formula:

[0166] CAT activity in tissue (U / mgprot) = ΔA × 271 × V 样 ÷T÷Cpr

[0167] In the formula: U—one activity unit is defined as the breakdown of 1 μmol of H2O2 per second by 1 milligram of tissue protein; ΔA—absorbance value; V 样 —Sampling volume, 0.05 mL; T—Reaction time, 60 s; Cpr: Protein concentration in tissue homogenate, mgprot·mL -1 , prot refers to protein.

[0168] Peroxidase is calculated using the following formula:

[0169]

[0170] In the formula: U—the amount of enzyme that catalyzes 1 μg of substrate per minute per milligram of tissue protein under 37℃ conditions is defined as one unit of enzyme activity, U; A—absorbance value; V 反总 —Total volume of the reaction system, 4 mL; V 样 —Sampling volume, 0.1 mL; T—Reaction time, 30 min; W—Fresh weight of tissue, g; V 样总 —Total volume of tissue homogenate, mL.

[0171] Total antioxidant capacity is calculated using the following formula:

[0172]

[0173] In the formula: U—at 37℃, the absorbance value of the reaction system per milligram of tissue protein per minute, each increase of 0.01 is one unit of total antioxidant capacity U; A—absorbance value; T—reaction time, 30 min; V 反总 —Total volume of the reaction system, mL; V 样 — Sample volume, mL; Cpr — Tissue homogenate protein concentration, mgprot·mL -1 , prot refers to protein.

[0174] Total superoxide dismutase is calculated using the following formula:

[0175]

[0176] In the formula: U—the amount of SOD corresponding to a 50% SOD inhibition rate per gram of tissue in 1 mL of reaction solution is one unit of SOD activity, U; A—absorbance value; V 反总 —Total volume of the reaction system, mL; V 样 —Sample volume, mL; C 匀浆 —Tissue homogenate concentration, g·mL -1 .

[0177] Each treatment was repeated three times in the above tests. ANOVA was performed on chlorophyll, chlorophyll fluorescence, mineral nutrients, maximum formaldehyde uptake rate, MDA, and enzyme activities (CAT, POD, T-AOC, T-SOD) of some plants. Statistical software was used to perform multiple comparisons (LSD, p = 0.05) of the means of different treatments. p < 0.05 and p < 0.01 were considered statistically significant and highly significant, respectively.

[0178] The formaldehyde concentration change curve in the box containing 6 plants is shown in the figure. Figure 3 As shown, the formaldehyde absorption rates of the six plants are as follows: Figure 4 As shown, the specific test data provided in this application are as follows:

[0179] In the formaldehyde absorption capacity test, the morphological characteristics of the six horticultural plants remained normal before and after the test, with no significant changes. This may be because the appearance of the plants does not show obvious changes in a short period of time after formaldehyde fumigation, and the absolute amount of formaldehyde applied in the sealed box was only 0.4 mg, which is relatively small and insufficient to cause significant damage to the plants in a short period of time.

[0180] Formaldehyde absorption rate: After formaldehyde was added to the sealed chamber, the formaldehyde concentration reached its peak after about 30 minutes, at which point the formaldehyde was almost completely volatilized, and the plant absorption rate reached its maximum. As fumigation time increased, the plants continuously absorbed formaldehyde, the formaldehyde concentration inside the chamber decreased, and the plant absorption rate also decreased. Analysis of variance was performed on the formaldehyde absorption rates of six plant species, and the results showed significant differences in their absorption rates. The maximum formaldehyde absorption rates, from highest to lowest, were: chrysanthemum > Nephrolepis cordifolia > Rhapis excelsa > Spathiphyllum > Anthurium > Aloe vera. Based on the monitored formaldehyde concentration data, the maximum formaldehyde absorption rate of chrysanthemum was 10.79 mg·m³. -2 ·h -1 The maximum absorption rate of formaldehyde by the remaining plants was 3.39 mg·m³. -2 ·h -1 2.59 mg·m -2 ·h -1 1.95 mg·m -2 ·h -1 1.19 mg·m -2 ·h -1 1.00 mg·m -2 ·h -1 .

[0181] The variance analysis of the maximum formaldehyde absorption rate of the six plant species is shown in Table 5 below. **** indicates that the difference is significant under the condition that Pr>F value<0.0001, and P represents the plant species.

[0182]

[0183] Table 5

[0184] The significance analysis of the maximum formaldehyde absorption rate of the six plants in the formaldehyde absorption capacity test is shown in Table 6 below. The same letter in the same column of the table indicates that there is no significant difference between the different treatment groups, while different letters indicate that there is a significant difference.

[0185] variety <![CDATA[Maximum formaldehyde absorption rate / (mg·m -2 ·h -1 )]]> chrysanthemum <![CDATA[10.79±0.26 a ]]> Nephrolepis cordifolia <![CDATA[3.39±0.13 b ]]> Bamboo palm <![CDATA[2.59±0.11 c ]]> Peace Lily <![CDATA[1.95±0.19 d ]]> Wedding candles <![CDATA[1.19±0.05 e ]]> Aloe vera <![CDATA[1.00±0.30 e ]]>

[0186] Table 6

[0187] In the formaldehyde absorption capacity test, the MDA content of the six plant species showed significant differences. All six plant species had relatively low MDA content, indicating that at a formaldehyde concentration of 5 mg / m³... -3 Under conditions where the absolute formaldehyde content in the sealed chamber was 0.4 mg, all six plants exhibited good tolerance. Comparing the MDA content of the six plants, chrysanthemum and Nephrolepis cordifolia showed significant differences compared to the other plants, while there were no significant differences between Spathiphyllum and Rhapis excelsa, and also no significant differences between Aloe vera and Anthurium. The MDA content, ranked from highest to lowest, was: Nephrolepis cordifolia > Rhapis excelsa > Spathiphyllum > Chrysanthemum > Aloe vera > Anthurium.

[0188] The variance analysis of MDA content in the six plant species is shown in Table 7 below. **** indicates that the difference is significant under the condition that Pr>F value<0.0001, and P represents the plant species.

[0189]

[0190] Table 7

[0191] The significance analysis of malondialdehyde content in the six plants after formaldehyde fumigation is shown in Table 8 below. In the table, the same letter in the same column indicates that there is no significant difference between the different treatment groups, while different letters indicate significant differences.

[0192] variety <![CDATA[MDA / (g·L -1 )]]> chrysanthemum <![CDATA[0.22±0.06 c ]]> Nephrolepis cordifolia <![CDATA[0.62±0.10 a ]]> Peace Lily <![CDATA[0.34±0.03 b ]]> Bamboo palm <![CDATA[0.43±0.12 b ]]> Aloe vera <![CDATA[0.07±0.05 d ]]> Wedding candles <![CDATA[0.02±0.02 d ]]>

[0193] Table 8

[0194] Chrysanthemums, nephrolepis, and bamboo palms absorb formaldehyde at a faster rate per unit leaf area than other plants. The formaldehyde concentration (5 mg / m³) in the sealed box was... -3 Reduced to the national standard (0.08 mg / mL) -3 The following tests were conducted: chrysanthemum and bamboo palm took 1.5 hours, while nephrolepis took 1 hour. All six plants had low MDA content. Considering all factors, three plants—chrysanthemum, nephrolepis, and bamboo palm—were selected for further testing.

[0195] In the formaldehyde tolerance test, the morphological characteristics of the three horticultural plants remained normal before and after the test, with no significant changes. There were no significant differences between the plants after fumigation with different concentrations of formaldehyde. Among the three plants, the Nephrolepis cordifolia exhibited higher plant height, leaf area, and biomass than the corresponding values ​​for the other two plants.

[0196] Significant differences in chlorophyll content were observed among different plants, and significant differences also existed in chlorophyll content among the same plant species across different formaldehyde concentration treatment groups. After fumigation with different concentrations of formaldehyde, the chlorophyll content of all three plant species decreased compared to untreated plants. The chlorophyll content of the chrysanthemum, *Nephrolepis cordifolia*, and *Rhapis excelsa* test groups decreased by the largest reductions, at 26%, 17%, and 15%, respectively. Analysis of variance was performed on the Fv / Fm values ​​of *Nephrolepis cordifolia*, chrysanthemum, and *Rhapis excelsa* after fumigation with different concentrations of formaldehyde. No significant differences were found in the Fv / Fm values ​​of *Nephrolepis cordifolia* and chrysanthemum, while the Fv / Fm value of *Rhapis excelsa* treatment 3 was significantly lower than that of the other treatment groups. The significance analysis of chlorophyll content in the three plant species for tolerance testing is shown in Table 7 below. The same uppercase letter indicates no significant difference between different treatment groups of the same plant, the same lowercase letter indicates no significant difference within the same treatment group, and different lowercase letters indicate significant differences.

[0197] The variance analysis of chlorophyll content of the three plants in the tolerance test is shown in Table 9 below. **** indicates that the difference is significant under the conditions of Pr>F value<0.05 and 0.0001, respectively. P represents the plant species and HCHO represents the formaldehyde concentration.

[0198]

[0199] Table 9

[0200] Table 10 below shows the significance analysis of chlorophyll content in the three plants in the tolerance test. The same uppercase letter indicates that there is no significant difference between different treatment groups of the same plant, the same lowercase letter indicates that there is no significant difference between plants in the same treatment group, and different letters indicate significant differences.

[0201]

[0202] Table 10

[0203] The variance analysis of the maximum photochemical efficiency of the three plant species in the tolerance test is shown in Table 11 below. ns indicates no significant difference, and **** indicates significant differences under the conditions of Pr>F value<0.05 and 0.0001. HCHO represents formaldehyde concentration, and P represents plant species.

[0204] factor F-value and statistical significance P <![CDATA[20.36 **** ]]> HCHO <![CDATA[4.60 * ]]> P×HCHO <![CDATA[2.39 ns ]]>

[0205] Table 11

[0206] The significance analysis of the maximum photochemical efficiency of the three plant species in the tolerance test is shown in Table 12 below. The same letter in the same column indicates that there is no significant difference between the different treatment groups, while different letters indicate significant differences.

[0207]

[0208]

[0209] Table 12

[0210] The formaldehyde absorption rate per unit leaf area of ​​the three plants was analyzed. With increasing formaldehyde concentration, the absorption rates of chrysanthemum, nephrolepis cordifolia, and bamboo palm all increased. The formaldehyde absorption rates of the three plants, from highest to lowest, were: chrysanthemum > nephrolepis cordifolia > bamboo palm. (Formaldehyde fumigation concentration: 15 mg / m³) -3 At that time, the maximum formaldehyde absorption rate of chrysanthemum reached 20.79 mg·m³. -2 ·h -1 The maximum formaldehyde absorption rate of Nephrolepis cordifolia reaches 12.07 mg / m³. -2 ·h -1 The maximum formaldehyde absorption rate of bamboo palm reaches 6.69 mg·m³. -2 ·h -1 Formaldehyde fumigation concentration 30 mg / m³ -3 At that time, the maximum formaldehyde absorption rate of chrysanthemum reached 37.30 mg·m³. -2 ·h -1 The maximum formaldehyde absorption rate of Nephrolepis cordifolia reaches 17.27 mg·m³. -2 ·h -1The maximum formaldehyde absorption rate of bamboo palm reaches 12.25 mg·m³. -2 ·h -1 Formaldehyde fumigation concentration: 60 mg / m³ -3 At that time, the maximum formaldehyde absorption rate of chrysanthemum reached 69.59 mg·m³. -2 ·h -1 The maximum formaldehyde absorption rate of Nephrolepis cordifolia reaches 48.52 mg / m³. -2 ·h -1 The maximum formaldehyde absorption rate of bamboo palm reaches 24.71 mg·m³. -2 ·h -1 The formaldehyde absorption rate of each plant increases with increasing formaldehyde concentration, further demonstrating that chrysanthemum, Nephrolepis cordifolia, and Rhapis excelsa all possess strong formaldehyde absorption capabilities. The formaldehyde absorption rates of Nephrolepis cordifolia, chrysanthemum, and Rhapis excelsa at different formaldehyde concentrations are shown below. Figure 5 As shown.

[0211] Analysis of variance (ANOVA) was performed on the MDA content of three plant species. Significant differences in MDA content were observed among the different plant species, and significant differences also existed in MDA content among different formaldehyde concentrations applied to the same plant species. An interaction effect was found between the plant species and the applied formaldehyde concentration.

[0212] With increasing formaldehyde application, the MDA content of the *Nephrolepis cordifolia* control group and treatment 1 showed no significant difference. Treatment 2 showed a significant difference in MDA content compared to other formaldehyde treatment groups. Treatment 3 showed a dramatic increase in MDA content, being 10 times that of the control group, indicating a significant difference between the two. For chrysanthemum, the MDA content of the control group differed significantly from other treatment groups, while the MDA content of chrysanthemum did not differ significantly among different formaldehyde concentrations, suggesting that chrysanthemum has strong tolerance to formaldehyde. For *Phyllostachys edulis*, the MDA content of the control group, treatment 1, and treatment 2 showed no significant difference. Treatment 3 for *Phyllostachys edulis* showed a significant difference in MDA content compared to the control group and the other two treatment groups, indicating that *Phyllostachys edulis* also suffered relatively less damage from formaldehyde fumigation and has strong tolerance to formaldehyde.

[0213] Among different plants, the MDA content of chrysanthemum and bamboo palm did not differ significantly, while the MDA content of Nephrolepis cordifolia differed significantly from the former two, with its MDA content being higher than the other two.

[0214] The variance analysis of MDA content in the three plants is shown in Table 13 below. **** indicates that the difference is significant under the condition that Pr>F value<0.0001. P represents plant species and HCHO represents formaldehyde concentration.

[0215]

[0216] Table 13

[0217] Significance analysis of MDA content in 3 plant species (g·L)-1 See Table 14 below. The same uppercase letter in the same column indicates that there is no significant difference between different treatments of the same plant. The same lowercase letter in the same row indicates that there is no significant difference between different treatments of the same plant. Different lowercase letters indicate significant differences.

[0218] <![CDATA[Formaldehyde concentration / mg·m -3 > CK Process 1 Process 2 Process 3 chrysanthemum <![CDATA[0.24±0.01 Aa ]]> <![CDATA[0.32±0.01 Ab ]]> <![CDATA[0.38±0.09 Ab ]]> <![CDATA[0.46±0.07 Ab ]]> Bamboo palm <![CDATA[0.24±0.01 Aa ]]> <![CDATA[0.34±0.11 Aa ]]> <![CDATA[0.48±0.01 Aa ]]> <![CDATA[0.61±0.15 Ab ]]> Nephrolepis cordifolia <![CDATA[0.17±0.08 Ba ]]> <![CDATA[0.53±0.06 Ba ]]> <![CDATA[1.06±0.34 Bb ]]> <![CDATA[2.65±0.42 Bc ]]>

[0219] Table 14

[0220] Analysis of variance was performed on the enzyme activities of chrysanthemum, Nephrolepis cordifolia, and Rhapis excelsa. Significant differences in enzyme activity were found among the different plants, as well as among the different treatment groups with different formaldehyde concentrations. Significant interactions were also observed between different plant varieties and different formaldehyde concentrations.

[0221] Overall, the TSOD enzyme activities of the three plant species showed significant differences. The TSOD enzyme activity of *Nephrolepis cordifolia* was higher than the other two, followed by *Phyllostachys edulis*, while *Chrysanthemum* showed the lowest TSOD activity. With increasing formaldehyde concentration, there was no significant difference in TSOD enzyme activity among the different formaldehyde treatment groups. The TSOD enzyme activity of the *Phyllostachys edulis* blank control group was significantly different from that of the different formaldehyde treatment groups, but there was no significant difference in TSOD enzyme activity among the different formaldehyde treatment groups. Similarly, the TSOD enzyme activity of the *Nephrolepis cordifolia* blank control group was significantly different from that of the different formaldehyde treatment groups, but there was no significant difference in TSOD enzyme activity among the different formaldehyde treatment groups.

[0222] Overall, the TAOC activities of the three plant species showed significant differences. The TAOC activity of *Phyllostachys edulis* was higher than the other two, followed by *Nephrolepis cordifolia*, while *Chrysanthemum* showed the lowest TAOC activity. With increasing formaldehyde concentration, there was no significant difference in TAOC activity among the different formaldehyde concentration treatment groups. The TAOC activity of *Phyllostachys edulis* treatments 2 and 3 showed no significant difference, while the differences among the other treatment groups were significant, especially when the formaldehyde concentration reached 15 mg / m³. -3 At that time, the TAOC activity of bamboo palm reached its maximum value of 19.22 U·g. -1 FW, when the formaldehyde concentration exceeds this limit, the TAOC activity of *Phyllostachys edulis* begins to decrease. There was no significant difference between the blank treatment and treatment 1 in *Nephrolepis cordifolia*, nor between treatments 2 and 3, but there were significant differences in TAOC between the first two and the latter two.

[0223] Overall, among the three plant species, *Phyllostachys edulis* exhibited the highest POD enzyme activity compared to the other two, followed by *Chrysanthemum*, while *Nephrolepis cordifolia* showed the lowest. With increasing formaldehyde concentration, there was no significant difference in POD enzyme activity among the different formaldehyde concentration treatment groups for *Chrysanthemum*. For *Phyllostachys edulis*, there was no significant difference between the blank treatment and treatment 1, nor between treatment 2 and treatment 3; however, there were significant differences between the first two treatments and the latter two. For *Nephrolepis cordifolia*, there were no significant differences among the blank treatment, treatment 1, and treatment 2; however, treatment 3 showed a significant difference in POD enzyme activity compared to the first three treatments.

[0224] Among them, in terms of the overall CAT enzyme activity of the three plants, the CAT enzyme activity of Nephrolepis cordifolia was significantly different from that of Chrysanthemum and Rhapis excelsa. The formaldehyde concentration was 15 mg·m³. -3 Increase to 60 mg·m -3 At that time, the CAT enzyme activity of *Nephrolepis cordifolia* increased threefold, and the CAT enzyme activity of *Nephrolepis cordifolia* was greater than that of chrysanthemum and *Rhapis excelsa*. There was no significant difference in CAT enzyme activity between chrysanthemum and *Rhapis excelsa*. The CAT enzyme activity of chrysanthemum in the blank formaldehyde treatment group was significantly different from that in treatments 1, 2, and 3, but there was no significant difference in CAT enzyme activity among the treatments 1, 2, and 3 of chrysanthemum. The CAT enzyme activity of *Rhapis excelsa* in treatment 3 was significantly different from that in the blank treatment, treatment 1, and treatment 2, while there was no significant difference in CAT enzyme activity between the blank treatment, treatment 1, and treatment 2.

[0225] The variance analysis of the activities of the three plant enzymes is shown in Table 15 below. **** indicates that the differences are significant under the conditions of Pr>F value<0.05 and 0.0001, respectively. P represents the plant species and HCHO represents the formaldehyde concentration.

[0226]

[0227] Table 15

[0228] The significance analysis of enzyme activity of the three plants is shown in Table 16 below. The same uppercase letter in the same column indicates that there is no significant difference between different treatments of the same plant, the same lowercase letter in the same column indicates that there is no significant difference between different plants of the same treatment, and different letters indicate significant differences.

[0229]

[0230] Table 16

[0231] In observing changes in the stomata of the microstructure, chrysanthemum leaves after fumigation with different concentrations of formaldehyde were collected. The results showed that at a formaldehyde concentration of 15 mg / m³, the changes in stomata were more pronounced. -3 At that time, the stomata of chrysanthemum leaves partially closed, and the opening of most stomata decreased; the formaldehyde concentration was 30 mg·m³. -3At this time, the number of stomata in chrysanthemum leaves decreased, and the stomata were almost completely closed; the formaldehyde concentration was 60 mg·m³. -3 At that time, the stomata on the chrysanthemum leaves had changed shape, from elliptical to rectangular, while the other stomata were closed.

[0232] Stomatal distribution of chrysanthemum leaves treated with different concentrations of formaldehyde (a) 15 mg·m -3 (b) 30 mg·m -3 (c) 60 mg·m -3 like Figure 6 As shown.

[0233] Leaves of *Nephrolepis cordifolia* were collected after fumigation with different concentrations of formaldehyde. Stomatal changes were observed, revealing that at a formaldehyde concentration of 15 mg / m³... -3 At that time, the stomatal opening of most of the leaves of the Nephrolepis cordifolia decreased significantly; the formaldehyde concentration was 30 mg·m³. -3 At that time, most of the stomata on the leaves of the Nephrolepis cordifolia were closed; the formaldehyde concentration was 60 mg·m³. -3 At that time, all the stomata on the leaves of the Nephrolepis cordifolia are tightly closed.

[0234] Stomatal distribution of Nephrolepis exaltata leaves treated with different concentrations of formaldehyde: (d) 15 mg·m -3 (e) 30 mg·m -3 (f) 60 mg·m -3 like Figure 7 As shown.

[0235] Leaves of *Phyllostachys edulis* were collected after fumigation with different concentrations of formaldehyde. Observations of stomatal changes revealed that at a formaldehyde concentration of 15 mg / m³, the changes were most pronounced. -3 At that time, the stomatal opening of most of the bamboo palm leaves decreased significantly; the formaldehyde concentration was 30 mg·m³. -3 At that time, the stomatal opening of the bamboo palm leaves was related to the formaldehyde concentration of 15 mg·m³. -3 There was no significant difference in the opening size under fumigation. The formaldehyde concentration was 30 mg / m³. -3 The stomata of the palm tree are almost completely closed.

[0236] Stomatal distribution of bamboo palm leaves treated with different concentrations of formaldehyde: (g) 15 mg·m -3 (h)30mg·m -3 (i) 60 mg·m -3 like Figure 8 As shown.

[0237] Observations on the changes in cell structure of chrysanthemum, Nephrolepis cordifolia, and Rhapis excelsa revealed that, compared with the control group, all three treatment groups showed a tendency for cell structure to shrink and aggregate, changes in organelle shape, reduction in chloroplasts, and larger fat granules. These changes were more pronounced in treatment groups with higher formaldehyde concentrations.

[0238] Chrysanthemum leaf cell structure treated with different concentrations of formaldehyde (a) 15 mg·m -3 (b) 30 mg·m -3 (c) 60 mg·m -3 like Figure 9 As shown, the cell structure of Nephrolepis leaf treated with different concentrations of formaldehyde: (d) 15 mg·m -3 (e) 30 mg·m -3 (f) 60 mg·m -3 like Figure 10 As shown, the cell structure of bamboo palm leaves treated with different concentrations of formaldehyde: (g) 15mg·m -3 (h)30mg·m -3 (i) 60 mg·m -3 like Figure 11 As shown.

[0239] The formaldehyde absorption rates of the three plants, ranked from highest to lowest, were chrysanthemum > Nephrolepis cordifolia > Rhapis excelsa. Chrysanthemum and Rhapis excelsa had formaldehyde absorption rates at least twice as fast as Rhapis excelsa. The chlorophyll content of all three plants was significantly reduced, with chrysanthemum having a relatively higher chlorophyll content. The maximum photochemical efficiency of chrysanthemum and Nephrolepis cordifolia showed no significant change, while the maximum photochemical efficiency of Rhapis excelsa was at a formaldehyde concentration of 30 mg·m³. -3 The formaldehyde content decreased significantly under treatment. Chrysanthemums were not sensitive to formaldehyde concentration, and the MDA content did not increase significantly. There were no significant differences in enzyme activity after different formaldehyde treatments. Formaldehyde concentrations exceeding 30 mg / m³... -3 At this time, most of the stomata in chrysanthemums close, chloroplasts decrease, and fat granules enlarge. Nephrolepis cordifolia is sensitive to formaldehyde concentrations, showing a significant increase in MDA content, and its enzyme activity increases significantly after different formaldehyde treatments. Formaldehyde concentrations exceeding 15 mg / m³... -3 At this time, most of the stomata of the Nephrolepis cordifolia close, chloroplasts decrease, and lipid granules enlarge. Chrysanthemum and Nephrolepis cordifolia exhibit relatively fast formaldehyde absorption rates and good tolerance; therefore, chrysanthemum and Nephrolepis cordifolia will be selected for further testing.

[0240] In the environmental impact formaldehyde absorption test, the morphology of the two horticultural plants was normal before and after the test, with no obvious changes.

[0241] When the light intensity is 200 μmol·m -2 s -1 Doubled to 400 μmol·m -2 s -1Subsequently, the formaldehyde absorption rates of Nephrolepis cordifolia and chrysanthemum increased. Increasing light intensity increased the formaldehyde absorption rate of Nephrolepis cordifolia by 0.58% at a carbon dioxide concentration of 500 ppm, by 0.24% at 1000 ppm, by 0.55% at 1500 ppm, and by 0.11% at 2000 ppm. Further increasing light intensity increased the formaldehyde absorption rate of chrysanthemum by 11.24% at 500 ppm, by 9.27% ​​at 1000 ppm, by 5.06% at 1500 ppm, and by 3.47% at 2000 ppm.

[0242] Formaldehyde absorption curves of Nephrolepis cordifolia at a carbon dioxide concentration of 500 ppm under different light intensities are shown below. Figure 12 As shown, the formaldehyde absorption curves of *Nephrolepis cordifolia* at different light intensities and carbon dioxide concentrations of 1000 ppm are as follows: Figure 13 As shown, the formaldehyde absorption curves of *Nephrolepis cordifolia* at different light intensities and carbon dioxide concentrations of 1500 ppm are as follows: Figure 14 As shown, the formaldehyde absorption curves of *Nephrolepis cordifolia* at different light intensities and carbon dioxide concentrations of 2000 ppm are as follows: Figure 15 As shown.

[0243] The formaldehyde absorption curves of chrysanthemums at a carbon dioxide concentration of 500 ppm under different light intensities are shown below. Figure 16 As shown, the formaldehyde absorption curves of chrysanthemum at different light intensities and carbon dioxide concentrations of 1000 ppm are as follows. Figure 17 As shown, the formaldehyde absorption curves of chrysanthemums at different light intensities and carbon dioxide concentrations of 1500 ppm are as follows. Figure 18 As shown, the formaldehyde absorption curves of chrysanthemum at different light intensities and carbon dioxide concentrations of 2000 ppm are as follows. Figure 19 As shown.

[0244] Compare the same light intensities (200, 400 μmol·m⁻¹) respectively. -2 s -1 Under the given conditions, the formaldehyde absorption rate per unit leaf area of ​​chrysanthemum and Nephrolepis cordifolia did not show a clear pattern among different carbon dioxide concentration treatment groups. High carbon dioxide concentration treatment did not promote the formaldehyde absorption rate of chrysanthemum. The formaldehyde absorption rate of Nephrolepis cordifolia did not increase with the application of high carbon dioxide concentration, and high carbon dioxide concentration treatment did not show a promoting effect on the formaldehyde absorption rate of Nephrolepis cordifolia. With prolonged fumigation time, the difference in formaldehyde absorption rate among different carbon dioxide concentration treatment groups decreased.

[0245] Formaldehyde absorption rate of chrysanthemums at different carbon dioxide concentrations (200 μmol·m -2 s -1 (Light) such as Figure 20 As shown, the formaldehyde absorption rate of chrysanthemums at different carbon dioxide concentrations (400 μmol·m⁻¹) -2 s -1 (Light) such as Figure 21 As shown, the formaldehyde absorption rate of Nephrolepis cordifolia at different carbon dioxide concentrations (200 μmol·m⁻¹) -2 s -1 (Light) such as Figure 22 As shown, the formaldehyde absorption rate of Nephrolepis cordifolia at different carbon dioxide concentrations (400 μmol·m⁻¹) -2 s -1 (Light) such as Figure 23 As shown.

[0246] Increasing light intensity can promote the formaldehyde absorption rate of chrysanthemum and nephrolepis, with a better promoting effect on chrysanthemum. The formaldehyde absorption rate of chrysanthemum and nephrolepis increased by a maximum of 11.24% and 0.58%, respectively. Increasing carbon dioxide concentration cannot promote the absorption of formaldehyde by chrysanthemum and nephrolepis.

[0247] The specific formaldehyde absorption capacity of horticultural plants includes: the formaldehyde concentration (5 mg / m³) per unit leaf area of ​​chrysanthemum, nephrolepis, and bamboo palm. -3 The absorption rate of formaldehyde is faster than that of other plants, with chrysanthemums having a maximum formaldehyde absorption rate of 10.79 mg·m³. -2 ·h -1 The formaldehyde absorption rates of chrysanthemum and Nephrolepis cordifolia were higher than those of Rhapis excelsa. By comparing the malondialdehyde (MDA) content in the leaves of each plant, the resistance of each plant to formaldehyde was preliminarily explored. The MDA content of all six plants was low (less than 0.62 g·L⁻¹). -1 Chrysanthemum, Nephrolepis cordifolia, and Rhapis excelsa, three horticultural plants with strong formaldehyde absorption capacity, were used for further tolerance testing.

[0248] In the formaldehyde tolerance test of horticultural plants, different concentrations of formaldehyde (15, 30, 60 mg / m³) were used. -3 Fumigation of chrysanthemum, nephrolepis cordifolia, and bamboo palm revealed a positive correlation between the formaldehyde absorption rate per unit leaf area and the formaldehyde concentration. Furthermore, at all three formaldehyde concentrations, the order of formaldehyde absorption rate was chrysanthemum > nephrolepis cordifolia > bamboo palm, with chrysanthemum exhibiting the highest formaldehyde absorption rate at 69.59 mg / m³. -2 ·h -1 .

[0249] Subjected to different concentrations of formaldehyde (15, 30, 60 mg / m³) -3After fumigation, all three plants showed a decrease in chlorophyll content with increasing formaldehyde concentration. The maximum photochemical efficiency of chrysanthemum and nephrolepis showed no significant change before and after fumigation, while the maximum photochemical efficiency of bamboo palm was 60 mg·m³. -3 Formaldehyde levels decreased significantly after fumigation.

[0250] Subjected to different concentrations of formaldehyde (15, 30, 60 mg / m³) -3 After fumigation, the MDA content of both *Nephrolepis cordifolia* and *Rhapis excelsa* increased significantly with increasing formaldehyde concentration, with *Nephrolepis cordifolia* showing the highest MDA content. There was no significant difference in MDA content between *Chrysanthemum* and *Phyllostachys pubescens*. With increasing formaldehyde concentration, the activities of various enzymes in *Chrysanthemum* did not increase significantly, while the activities of various enzymes in *Nephrolepis cordifolia* increased significantly, especially TSOD, POD, and CAT enzymes, which increased by 2 times, 5.7 times, and 4 times, respectively. The activities of various enzymes in *Phyllostachys pubescens* also increased significantly, except for TAOC activity, which initially increased and then decreased.

[0251] With varying formaldehyde concentrations during fumigation (15, 30, 60 mg / m³) -3 As the concentration of stomata increases, the stomatal aperture and the number of stomata in chrysanthemum decrease, 60 mg·m -3 Formaldehyde fumigation altered the stomatal morphology of chrysanthemums, although the stomata remained open. In contrast, the stomatal aperture of Nephrolepis cordifolia was significantly reduced (60 mg / m³). -3 After formaldehyde fumigation, all stomata on the leaves of Nephrolepis cordifolia were completely closed. The difference in stomata among the leaves of Rhapis excelsa fumigated with different formaldehyde concentrations was the most obvious. As the formaldehyde concentration increased, the leaves of Rhapis excelsa fumigated with palms exhibited three states: mostly open, reduced opening, and almost completely closed.

[0252] Subjected to different concentrations of formaldehyde (15, 30, 60 mg / m³) -3 After fumigation, the cell structures of chrysanthemum, nephrolepis, and bamboo palm showed a tendency to shrink and aggregate inward, the shape of organelles changed, chloroplasts decreased, and fat granules became larger. These changes were more pronounced in treatment groups with higher formaldehyde concentrations.

[0253] In environmental impact tests on formaldehyde absorption by horticultural plants, increasing carbon dioxide concentrations (1000, 1500, 2000 ppm) did not effectively increase the formaldehyde absorption rate of chrysanthemums and Nephrolepis cordifolia. Increasing light intensity to 400 μmol·m⁻² was also effective. -2 s -1 Light exposure can effectively increase the formaldehyde absorption rate of chrysanthemum, but has a smaller effect on the formaldehyde absorption rate of nephrolepis. The largest increase is observed at a carbon dioxide concentration of 500 ppm, with chrysanthemum and nephrolepis showing increases of 11.24% and 0.58% in formaldehyde absorption, respectively.

[0254] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0255] In view of the detailed description above, these and other changes can be made to these embodiments, and this written description includes embodiments of the best mode that disclose the invention. The patent scope of the invention is defined by the claims, which are not limited by this disclosure. The scope of protection of the invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the invention disclosed herein, based on the technical solutions and concepts of the invention, are within the scope of protection of the invention.

Claims

1. A device for measuring formaldehyde absorption by horticultural plants, characterized in that, include: A sealed box (1) is made of light-transmitting material. The sealed box (1) includes a box body and a box door. The box body and the box door can be enclosed to form a sealed space. The sealed box (1) is provided with an air inlet (11) and an air outlet (10). LED plant light (2) is installed above the outside of the sealed box (1) to provide light to the horticultural plants in the sealed space through the sealed box (1); A circulating fan (4) is disposed inside the sealed box (1); A formaldehyde volatilization table (5) is placed in front of the circulating fan (4) and is used to place a petri dish (6) containing formaldehyde solution. The circulating fan (4) is used to uniformly dissipate formaldehyde gas in the sealed box (1). A formaldehyde measuring instrument (13) monitors the formaldehyde concentration parameters in the sealed box (1) in real time through a first gas measuring circuit. The first gas measuring circuit is connected to the air inlet (11) and the air outlet (10) respectively. A carbon dioxide measuring instrument (14) monitors the carbon dioxide concentration parameter in the sealed box (1) in real time through a second gas measuring circuit. The second gas measuring circuit is connected to the inlet (11) and the outlet (10) respectively. A carbon dioxide supply device is used to inject carbon dioxide into the sealed box (1) and adjust the carbon dioxide concentration in the sealed box (1); Auxiliary measuring instrument (18) is used to measure the physiological indicators of horticultural plants.

2. The formaldehyde absorption measuring device for horticultural plants according to claim 1, characterized in that, The horticultural plants include at least one of chrysanthemum, Nephrolepis cordifolia, Rhapis excelsa, Anthurium andraeanum, Aloe vera, and Spathiphyllum.

3. The formaldehyde absorption measuring device for horticultural plants according to claim 1, characterized in that, Also includes: Temperature and humidity sensor (7), the temperature and humidity sensor (7) is installed inside the sealed box (1) and is used to detect the temperature and humidity inside the sealed box (1); Formaldehyde measuring instrument (13) is set outside the sealed box (1). It draws gas from the sealed box (1) through the first gas measuring circuit to measure the formaldehyde concentration. After the measurement is completed, the gas is transported back into the sealed box (1). A carbon dioxide measuring instrument (14) is located outside the sealed box (1). The carbon dioxide measuring instrument (14) draws gas from the sealed box (1) through a second gas measuring circuit to measure the carbon dioxide concentration. After the measurement is completed, the gas is transported back into the sealed box (1).

4. The formaldehyde absorption measuring device for horticultural plants according to claim 3, characterized in that, The first gas measurement circuit includes a first gas outlet and a first gas inlet. One end of the first gas outlet is connected to the gas outlet (10), and the other end of the first gas outlet is connected to the input end of the formaldehyde measuring instrument (13). One end of the first gas inlet is connected to the output end of the formaldehyde measuring instrument (13), and the other end of the first gas inlet is connected to the gas inlet (11). The second gas measurement circuit includes a second gas outlet and a second gas inlet. One end of the second gas outlet is connected to the gas outlet (10), and the other end of the second gas outlet is connected to the input end of the carbon dioxide measuring instrument (14). One end of the second gas inlet is connected to the output end of the carbon dioxide measuring instrument (14), and the other end of the second gas inlet is connected to the gas inlet (11).

5. The formaldehyde absorption measuring device for horticultural plants according to claim 3, characterized in that, The carbon dioxide supply equipment includes: Carbon dioxide cylinder (15) is used to store carbon dioxide gas; The pipeline is connected at one end to the gas cylinder and at the other end to the air inlet (11). The gas cylinder delivers carbon dioxide gas into the sealed box (1) through the pipeline. A pressure reducing valve (16) is installed on the pipeline to regulate the pressure of carbon dioxide gas flow in the pipeline; A mass flow meter (17) is installed on the pipeline to measure the mass flow rate of carbon dioxide gas flow in the pipeline.

6. The formaldehyde absorption measuring device for horticultural plants according to any one of claims 1-5, characterized in that, The auxiliary measuring instrument (18) includes: Chlorophyll meter (19) is used to measure the chlorophyll content of leaves of horticultural plants; A handheld chlorophyll fluorometer (20) is used to process the fluorescence properties of horticultural plant leaves; Leaf area meter (21), used to measure the area of ​​leaves of horticultural plants; A projection electron microscope (22) was used to observe the ultrastructural changes of horticultural plant cells; Scanning electron microscope (23) is used to observe the surface structure of leaves of horticultural plants; An electronic balance (24) is used to weigh the biomass of horticultural plants, the biomass including fresh weight and / or dry weight; A spectrophotometer (25) was used for colorimetric determination of malondialdehyde, protein and enzyme content in the leaves of horticultural plants. Electric constant temperature drying oven (26) is used to dry horticultural plants.

7. A method for measuring formaldehyde absorption by horticultural plants, characterized in that, The formaldehyde absorption measuring device for horticultural plants as described in any one of claims 1-6, wherein the measuring method comprises the following steps: A variety of test plants were selected to test their formaldehyde absorption capacity. After the formaldehyde absorption capacity test, select at least three horticultural plants with strong formaldehyde absorption capacity to conduct a plant formaldehyde absorption tolerance test. After the formaldehyde tolerance test, horticultural plants with strong formaldehyde tolerance were selected to test the impact of environmental factors on the absorption of formaldehyde by horticultural plants.

8. The method for measuring formaldehyde absorption by horticultural plants according to claim 7, characterized in that, The formaldehyde absorption capacity test steps include: Multiple plants to be tested were tested in batches. Each test used multiple sealed boxes as parallel groups for formaldehyde fumigation and one as a blank control group. Multiple pots of the same type and with the same growth status were placed in each sealed box. Before the test, the plant leaves were sprayed with pure water to eliminate the influence of microorganisms, and the culture pot was wrapped with black plastic film to isolate the adsorption of the substrate. The environmental conditions inside the sealed chamber were adjusted to a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m. -2 s -1 Humidity 70%, temperature 25±1℃, and preset light cycle time; Add 40 μL of a 10.2 mg / mL formaldehyde standard solution to the formaldehyde volatilization platform to bring the theoretical formaldehyde concentration inside the sealed box to 5 mg / mL. -3 ; During fumigation, formaldehyde concentration and CO2 concentration were measured at regular intervals. After the fumigation, the leaf area, biomass, chlorophyll, and malondialdehyde content of the plants were measured to screen out the plants with the best formaldehyde absorption capacity.

9. The method for measuring formaldehyde absorption by horticultural plants according to claim 8, characterized in that, The formaldehyde tolerance test steps include: Several plants with the best formaldehyde absorption capacity were selected and cultivated using granular soil substrate; The selected plants were tested in batches. Multiple sealed boxes were used for each test, with blank control and multiple different formaldehyde concentration gradients set up. The concentration was controlled by precisely adding 10.2 mg / mL formaldehyde standard solution, and an equal amount of solution was added after a period of time. Maintain a CO2 concentration of 500 ppm ± 100 ppm and a light intensity of 200 ± 50 μmol·m⁻² inside the sealed chamber. -2 s -1 Temperature 25±1℃, humidity 70%, preset photoperiod time; During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain stable concentrations. After the test, the plant tolerance was comprehensively evaluated by appearance changes, physiological indicators and microstructure, and the best plants were selected.

10. The method for measuring formaldehyde absorption by horticultural plants according to claim 9, characterized in that, The test on the impact of environmental factors on formaldehyde absorption by horticultural plants includes: Several plants that had passed tolerance tests were selected and cultured in a granular soil substrate. Multiple plants were placed in each sealed box, and a black plastic film was used to isolate the substrate from adsorption. 0.48 mL of a 10.2 mg / mL formaldehyde standard solution was simultaneously injected into multiple sealed boxes. A CO2 concentration gradient was set, and the light intensity was kept constant at 200 ± 50 μmol·m⁻² during the first stage. -2 s -1 ; During fumigation, formaldehyde and CO2 concentrations are measured at regular intervals, and CO2 is dynamically replenished to maintain the set concentrations. The second stage will increase the light intensity to 400±50 μmol·m -2 ·s -1 Repeat the fumigation process.

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