Microbial inoculant application soil remediation method based on hydrogen peroxide pretreatment

Abstract

The application belongs to the technical field of soil ecological improvement and microbial agent application, and specifically discloses a microbial agent application soil remediation method based on hydrogen peroxide pretreatment, which comprises the following steps: first, hydrogen peroxide solution is sprayed into the soil, and after mixing, the soil is left to stand for 30-60 min, until the residual amount of hydrogen peroxide in the soil is below a set value, then microbial agents are applied to the soil, mixed, and soil remediation is performed. The residual hydrogen peroxide content in the soil is accurately controlled by quantitatively controlling the agent addition parameters, the optimal inoculation window period of 30-60 min is locked, and on the basis of guaranteeing the soil sterilization effect and avoiding the damage to the soil aggregate structure, the planting survival rate and long-term stability of exogenous functional bacteria in the soil environment are improved.

Description

Technical Field

[0001] This invention belongs to the field of soil ecological improvement and microbial agent application technology, specifically relating to a method for soil remediation based on the application of microbial agents with hydrogen peroxide pretreatment. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Soil faces severe challenges, including soil degradation due to declining organic matter and the accumulation of pollutants such as heavy metals and pesticide residues. Microbial inoculants can improve soil by activating nutrients and degrading toxins, offering advantages of being green and efficient. However, their effectiveness often suffers from colonization difficulties and loss of activity due to competition and antagonism between functional bacteria and native soil microorganisms.

[0004] Spraying hydrogen peroxide can disinfect soil pathogens, harmful dormant spores, and weed seeds. By reducing the population density of native microorganisms and creating ecological niches, it creates a suitable environment for the colonization of exogenous microorganisms. However, in practice, quantitative control is generally lacking, and the dosage and settling time are often applied extensively based on experience. When the dosage is too low, the elimination of native soil microorganisms is insufficient, and the remaining native microorganisms continue to crowd out the living space of exogenous microorganisms; excessive application can easily damage the soil aggregate structure and disturb the original soil physicochemical and microecological properties. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a soil remediation method based on the application of microbial agents pretreated with hydrogen peroxide, thereby achieving stable ecological niche vacancy in the soil and adapting it for subsequent inoculation with exogenous microbial agents.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention provides a method for soil remediation based on the application of microbial agents pretreated with hydrogen peroxide, comprising the following steps: First, spray hydrogen peroxide solution onto the soil, mix well, and let it stand for 30-60 minutes until the residual amount of hydrogen peroxide in the soil drops below the set value. Then, apply microbial agents to the soil, mix well, and carry out soil remediation.

[0007] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: This invention avoids the drawbacks of excessive application of hydrogen peroxide damaging soil structure and insufficient application failing to effectively disinfect native bacteria by quantitatively limiting the concentration and volume of hydrogen peroxide spraying, thus achieving a balance between sterilization effect and protection of the original properties of the soil.

[0008] By regularly tracking changes in pesticide residues and microbial numbers, the system can accurately pinpoint the 30-minute timeframe for complete pesticide degradation and the 30-60 minute optimal cultivation window. This approach avoids the toxicity of residual hydrogen peroxide to subsequent introduced strains and prevents the resurgence of native microorganisms from reclaiming vacant ecological niches, significantly improving the survival rate and long-term stability of subsequent inoculants.

[0009] This invention relies on simple and conventional testing methods to complete parameter calibration, offering strong process controllability and ease of operation, facilitating large-scale field application. Furthermore, the method has a wide range of applications, including farmland soil improvement, ecological restoration of degraded soils, and field application of microbial agents. Attached Figure Description

[0010] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0011] Figure 1 This is a graph showing the changes in hydrogen peroxide concentration in the soil at different times in Example 1 of the present invention; Figure 2 This is a comparison chart of the changes in microbial biomass over time under different H2O2 dosages in Example 1 of the present invention.

[0012] Figure 3 This is a comparison chart of the effect of different H2O2 dosages on the release of available phosphorus in the soil after pretreatment with microbial agents; Figure 4 This is a comparison chart of the effects of different H2O2 dosages of bacterial agents on the content of soil alkaline nitrogen in Example 2 of the present invention. Detailed Implementation

[0013] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0014] To address the technical problems mentioned in the background art, the present invention provides a method for soil remediation based on the application of microbial inoculants pretreated with hydrogen peroxide, comprising the following steps: First, spray hydrogen peroxide solution onto the soil, mix well, and let it stand for 30-60 minutes until the residual amount of hydrogen peroxide in the soil drops below the set value. Then, apply microbial agents to the soil, mix well, and carry out soil remediation.

[0015] In some embodiments, the concentration of the hydrogen peroxide solution is <10%, where % is a mass percentage.

[0016] Preferably, the concentration of the hydrogen peroxide solution is 5-10%, where % is a mass percentage.

[0017] More preferably, the concentration of the hydrogen peroxide solution is 8-10%, where % is a mass percentage.

[0018] More preferably, the concentration of the hydrogen peroxide solution is 9-10%, where % is a mass percentage.

[0019] Preferably, the volume of the hydrogen peroxide solution sprayed per 100g of soil is 3-10 ml.

[0020] More preferably, the volume of the hydrogen peroxide solution sprayed per 100g of soil is 3-7 ml.

[0021] In some embodiments, the microbial agent is applied to the soil 30-60 minutes after the hydrogen peroxide solution is sprayed.

[0022] Preferably, the microbial agent is applied to the soil 30-50 minutes after the hydrogen peroxide solution is sprayed.

[0023] Further preferably, the microbial agent is applied to the soil 40-50 minutes after the hydrogen peroxide solution is sprayed.

[0024] The present invention will be further described below with reference to the embodiments.

[0025] Example 1 This invention includes experiments with gradient concentrations and dosages. Specifically, hydrogen peroxide concentrations of 0-15% were prepared and sprayed evenly onto 100g of soil at dosages of 0 mL, 5 mL, 10 mL, and 15 mL, and then mixed thoroughly. Initially, the soil exhibited a loose, granular structure with uniform particle distribution, no obvious compaction or caking, and a loose, dry powdery texture, maintaining its original structural state. After adding 5-10 mL of 2.5%-10% H2O2, the soil remained loose, with a largely intact granular structure, generally moist, without obvious caking, and exhibiting good structural stability. Excessive dosage resulted in significant caking, destruction of the granular structure, formation of large, heavy, sticky clumps of wet soil, and particle adhesion, exhibiting a clear compacted state. Note: From the perspective of soil properties, adding 15 mL / 100g of 2.5%-10% H2O2 is more suitable.

[0026] Add 7 mL of 2.5%-10% H2O2 to 100 g of soil, and take samples for extraction at 0, 15, 30, 45, 60, and 75 min. Quantitatively determine the residual hydrogen peroxide content in the soil using hydrogen peroxide paper to understand the degradation pattern of hydrogen peroxide in the soil.

[0027] like Figure 1 As shown, using the third column of the colorimetric card as a reference, the change trend of the amount of residual H2O2 in the soil over time after the addition of 2.5% and 10% H2O2 was observed. It was found that after standing for 30 min, the residual hydrogen peroxide in the soil decreased to below the detection limit. At the same time, the change in the number of indigenous microorganisms was characterized by the dilution plating method.

[0028] like Figure 2 As shown, soil microbial biomass exhibited a dynamic trend of "first decreasing and then increasing" after treatment with different concentrations of hydrogen peroxide. The number of indigenous microorganisms reached its lowest point 30 minutes after pretreatment; after 24 hours of settling, the microbial biomass in all treatment groups significantly increased. These experiments demonstrate that these parameters effectively reduce the density of indigenous microbial populations, provide available ecological niches, and prevent damage to soil aggregate structure and original physiological and chemical properties. H2O2 is completely degraded after 30 minutes of addition and will not pose a continuous threat to subsequent inoculants; therefore, 30-60 minutes is defined as the optimal window for exogenous bacterial inoculation. This pretreatment method can stably optimize the soil microecological habitat and significantly improve the colonization survival rate and stability of exogenous functional bacteria.

[0029] Example 2 1) The soil samples were taken from moderately saline-alkali soil at the mouth of the Yellow River. After removing impurities, the soil samples were divided into 12 portions of 500 g each for later use.

[0030] 2) Prepare 100 mL of each of the following hydrogen peroxide solutions with gradient concentrations: 0% (CK), 2.5%, 5%, and 10%.

[0031] 3) Expand the culture of 14 salt-tolerant phosphate-solubilizing bacteria and 7 nitrogen-fixing bacteria, adjust the concentration of each bacterial solution to be consistent, centrifuge and resuspend, and prepare a mixed bacterial agent for later use (approximately 10). 8 (units / mL).

[0032] 4) Apply hydrogen peroxide solution of different concentrations evenly to the soil sample at a rate of 3.5 mL / 100 g soil, mix well and let stand for 30 min; then inoculate with mixed bacterial agent at a rate of 2.5 mL bacterial solution / 100 g soil, mix well and fill pot.

[0033] 5) On the 7th day of the experiment, samples were taken to measure soil available phosphorus, available nitrogen, and other indicators to observe the effect of soil improvement on saline-alkali soil.

[0034] The results show that: Compared with the control group, the contents of available phosphorus and available nitrogen in the soil of the hydrogen peroxide treatment groups were increased to varying degrees, and the 10% concentration treatment group showed the most significant improvement. Figure 3 and Figure 4 As shown.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the 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.

Claims

1. A method for soil remediation based on the application of microbial inoculants pretreated with hydrogen peroxide, characterized in that: Includes the following steps: First, spray the soil with a set dose of hydrogen peroxide solution, mix well, and let it stand for 30-60 minutes until the residual amount of hydrogen peroxide in the soil drops below the set value. Then, apply microbial agents to the soil, mix well, and carry out soil remediation.

2. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 1, is characterized in that: The concentration of the hydrogen peroxide solution is <10%, where % is a mass percentage.

3. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 2, is characterized in that: The concentration of the hydrogen peroxide solution is 5-10%, where % is a mass percentage.

4. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 3, is characterized in that: The concentration of the hydrogen peroxide solution is 8-10%, where % is a mass percentage.

5. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 4, is characterized in that: The concentration of the hydrogen peroxide solution is 9-10%, where % is a mass percentage.

6. The method for soil remediation based on hydrogen peroxide pretreatment using microbial inoculants, as described in claim 1, is characterized in that: The volume of the hydrogen peroxide solution sprayed per 100g of soil is 3-10ml.

7. The method for soil remediation based on hydrogen peroxide pretreatment using microbial inoculants, as described in claim 6, is characterized in that: The volume of the hydrogen peroxide solution sprayed per 100g of soil is 3-7ml.

8. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 1, is characterized in that: The timing for applying microbial agents to the soil is 30-60 minutes after spraying hydrogen peroxide solution.

9. The method for soil remediation based on hydrogen peroxide pretreatment using microbial agents, as described in claim 8, is characterized in that: The timing for applying microbial agents to the soil is 30-50 minutes after spraying hydrogen peroxide solution.

10. The method for soil remediation based on hydrogen peroxide pretreatment using microbial inoculants according to claim 9, characterized in that: The timing for applying microbial agents to the soil is 40-50 minutes after spraying hydrogen peroxide solution.

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