Mine soil remediation agent and preparation method thereof
By loading microbial agents on biochar to prepare soil repair agents, the problems of high cost of mine soil repair, long cycle and secondary pollution are solved, and efficient and sustainable soil repair and ground abilities are achieved.
Patent Information
- Application Number
- CN202510402599.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2025-07-11
AI Technical Summary
Existing mining soil restoration technologies have problems such as high cost, potential damage to soil structure or introducing secondary pollution, long repair cycles and effects are affected by environmental conditions.
将微生物菌剂负载到生物炭上,通过浸渍和物理活化制备矿山土壤修复剂,提高微生物在土壤中的留存时间和修复效果。
It has achieved long-term repair of microorganisms in the soil and increased ground abilities, forming semi-permanent sealing of biochar, with green and low-carbon properties.
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Figure CN120290188A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of environmental protection technologies. Specifically, it relates to a mine soil remediation agent and a preparation method thereof. Background Art
[0002] Currently, the main methods for mine soil remediation are as follows:
[0003] Physical remediation method: Physical remediation mainly separates or immobilizes pollutants through physical means to reduce their migration and diffusion. Commonly used physical remediation methods include soil replacement method (covering contaminated soil with clean soil to reduce pollutant concentration), soil replacement method (excavating contaminated soil and replacing it with clean soil), isolation method (using barrier materials to isolate contaminated soil to prevent pollutant diffusion), heat treatment (volatilizing or decomposing organic pollutants through high-temperature heating), etc. It has the advantages of quick effect and simple operation, but the treatment cost is relatively high and it may damage the soil structure.
[0004] Chemical remediation method: Chemical remediation uses chemical reactions to fix, transform or remove pollutants. Commonly used chemical remediation methods include chemical fixation (adding reagents such as lime and phosphate to convert heavy metals into stable compounds), chemical leaching (using acid, base or chelating agent solutions to leach soil to extract heavy metals), redox (degrading organic pollutants or changing the valence state of heavy metals through oxidants (such as hydrogen peroxide) or reductants (such as zero-valent iron)), etc. It has the advantages of high remediation efficiency and being applicable to large-area pollution, but it may introduce secondary pollution and change the soil properties.
[0005] Biological remediation method: Biological remediation uses plants, microorganisms or enzymes to degrade or adsorb pollutants. Commonly used biological remediation methods include phytoremediation (phytoremediation: planting hyperaccumulator plants to absorb heavy metals and concentrating them for treatment after harvesting; phytostabilization: using plant roots to immobilize pollutants and reduce migration; phytovolatilization: plants absorb pollutants and convert them into gaseous form for release), microbial remediation (using specific microorganisms to degrade organic pollutants or convert heavy metals into low-toxic forms), enzyme remediation (using enzymes to catalytically degrade organic pollutants). It has the advantages of being eco-friendly and low cost, but the remediation period is long and the effect is affected by environmental conditions.
[0006] Ecological remediation method: Ecological remediation realizes the long-term stability of soil by restoring vegetation and ecosystem functions. Commonly used methods include vegetation restoration (planting pollution-tolerant plants to gradually restore soil ecological functions), soil improvement (adding organic materials to improve soil structure and fertility), ecological engineering (constructing artificial wetlands or ecological barriers to reduce pollutant migration), etc. It has the advantages of strong sustainability and improving the ecological environment, but the remediation period is relatively long and the initial effect is not obvious. Summary of the Invention
[0007] The purpose of this application is to provide a mine soil conditioner and its preparation method. This mine soil conditioner loads microbial inoculants onto biochar and plays a role in repairing the soil and improving soil fertility from two dimensions, with better application effects.
[0008] The purpose of this application is achieved through the following technical solutions:
[0009] A preparation method of a mine soil conditioner, characterized by comprising the following steps:
[0010] S1. Obtain biochar by subjecting biochar raw materials to crushing pretreatment and high-temperature combustion;
[0011] S2. Add the biochar to a liquid composite microbial inoculant for impregnation;
[0012] S3. Dry the biochar impregnated with the composite microbial inoculant, and then perform physical activation in an aerobic environment to obtain the mine soil conditioner.
[0013] The beneficial effects of this application:
[0014] 1. This application loads microbial inoculants onto biochar, which can increase the retention time of microbial inoculants in the soil, enabling the microorganisms to have a longer effect.
[0015] 2. This application can play a role in repairing the soil and improving soil fertility from two dimensions of microorganisms and biomass, with better application effects.
[0016] 3. When this application is used, burying the biochar in the soil such as farmland can form a semi-permanent sequestration state of biochar. Therefore, it can also achieve soil carbon sequestration of biochar, generate carbon sinks, and has the attribute of green and low-carbon.
[0017] The main solution of the foregoing application and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and claimed in this application; and in this application, (each non-conflicting alternative) can be freely combined with each other and with other alternatives. Those skilled in the art can understand that there are various combinations according to the prior art and common general knowledge after understanding the solution of this application, all of which are the technical solutions to be protected in this application and will not be enumerated here. Description of the Drawings
[0018] Figure 1 It is a diagram of the usage situation of the soil conditioner prepared in Example 1 of this application. Detailed Embodiments
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be described clearly and completely below. For those not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.
[0020] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. This application will be described in detail below with reference to specific embodiments.
[0021] A preparation method of a mine soil remediator includes the following steps:
[0022] S1. Obtain biochar by subjecting biochar raw materials to crushing pretreatment and high-temperature combustion.
[0023] S2. Add the biochar to a liquid composite bacterial agent for impregnation.
[0024] S3. Dry the biochar impregnated with the composite bacterial agent, and then perform physical activation in an aerobic environment to obtain the mine soil remediator.
[0025] In some embodiments of this application, the biochar raw materials in the above S1 step include wood, straw, or tobacco waste.
[0026] In some embodiments of this application, the crushing pretreatment in the above S1 step is specifically to crush the biochar raw materials into slag with a length ≤ 5 cm or a diameter ≤ 5 cm.
[0027] In some embodiments of this application, the high-temperature combustion temperature in the above S1 step is 700 - 1000 °C, and the time is 3 hours. (After combustion to form char at this temperature, the N content is 0.375% - 2.221%, the C content is 38.568% - 65.889%, the H content is 0.856% - 3.756%, the S content is 0.518% - 0.797%, and the O content is 10.680% - 25.058%).
[0028] In some embodiments of this application, the ratio of the biochar to the liquid composite bacterial agent in the above S2 step is 1 g:5 mL, and the impregnation time is 36 - 48 h.
[0029] In some embodiments of this application, the above composite bacterial agent includes Bacillus subtilis, Bacillus licheniformis, yeast, and photosynthetic bacteria, and their ratio is Bacillus subtilis (≥ 45%), Bacillus licheniformis (≥ 30%), yeast (5% - 10%), and photosynthetic bacteria (10% - 15%). The liquid composite bacterial agent can be recycled as an impregnation solution 10 times without affecting the impregnation effect.
[0030] In some embodiments of the present application, in the above step S3, the drying temperature is 25 - 30 °C, and drying is carried out until constant weight. The constant weight means that the weight does not change after weighing continuously twice at an interval of 30 minutes.
[0031] In some embodiments of the present application, the activation temperature is 30 - 40 °C, the activation time is 30 - 60 min, and the oxygen content is 15% - 30%.
[0032] A mine soil remediation agent prepared by the above method.
[0033] The features and performance of the present application are further described in detail below in conjunction with embodiments.
[0034] Example 1
[0035] The selected land is cadmium - polluted land, with an initial cadmium concentration of 10.63 mg / kg, a soil bulk density of 0.81 g / cm 3 , and the soil organic matter content is 0.06%.
[0036] S1: Select wood as the raw material for biochar. First, it is subjected to crushing pretreatment until it is crushed into slag with a length ≤ 5 cm, and then enters the combustion stage. The combustion temperature is 850 °C to obtain biochar.
[0037] S2: Place the biochar in the composite microbial agent according to the ratio of biochar: liquid composite microbial agent of 1 g: 5 ml for impregnation, and the impregnation time is 36 hours. The main components of the liquid composite microbial agent are approximately: 55% Bacillus subtilis, 30% Bacillus licheniformis, 5% yeast, and 10% photosynthetic bacteria.
[0038] S3: Take out the impregnated biochar, put it into a cloth bag, tie the bag mouth tightly, and put it into a drying oven for drying until constant weight; then place it in a biochar activation box, fill it with oxygen as the activator, with an oxygen content of 15% - 30%, an activation time of 45 minutes, and an activation temperature of 35 °C; to obtain the soil remediation agent.
[0039] S4: Apply the soil remediation agent evenly at a dosage of 200 kg / mu, and turn the soil to a depth of 30 cm.
[0040] S5: Take samples for testing after 180 days.
[0041] Subsequently, the soil remediation agent prepared in the present application was used as a fertility remediation agent in farmland in Neijiang, and as Figure 1 shown, the final effect was remarkable.
[0042] Example 2
[0043] The preparation method and testing method of this example are basically the same as those of Example 1, except that the raw material for preparing biochar is tobacco leaves.
[0044] Example 3
[0045] The preparation method and testing method of this example are basically the same as those of Example 1, except that the raw material for preparing the biochar is corn straw.
[0046] The main components of the biochar after carbonization in Examples 1 - 3 (the product after Step S1) were analyzed (each test was repeated 2 times), and the main components are shown in Table 1.
[0047] Table 1
[0048] Embodiment N(％) C(％) H(％) S(％) O(％) C / H 1 0.498 38.568 1.262 0.548 11.400 30.56 1 0.569 38.681 1.161 0.555 11.793 33.31 2 2.174 47.751 3.401 0.797 25.058 14.00 2 2.221 47.786 3.756 0.789 24.903 12.72 3 0.357 65.907 0.890 0.518 10.713 74.05 3 0.375 65.889 0.856 0.556 10.680 76.97
[0049] The soil remediation test results of the soil remediation agents prepared in Examples 1 - 3 are shown in Table 2.
[0050] Table 2
[0051]
[0052] It can be concluded from Table 1 and Table 2 that the soil bulk density and the adsorption of heavy metals are related to the C content after carbonization. The C content is directly proportional to the bulk density and inversely proportional to the heavy metal adsorption capacity. Eventually, it is related to the ratio of C / H of the biomass entering the soil. Too high or too low C / H will affect the biomass.
[0053] Example 4
[0054] The preparation method and testing method of this example are basically the same as those of Example 1, except that the temperature of the combustion stage of the wood biochar in S1 is 700 °C.
[0055] Example 5
[0056] The preparation method and testing method of this example are basically the same as those of Example 1, except that the temperature of the combustion stage of the wood biochar in S1 is 1000 °C.
[0057] The soil remediation test results of the soil remediation agents prepared in Examples 1, 4, and 5 are shown in Table 3.
[0058] Table 3
[0059]
[0060] It can be concluded from Table 3 that the combustion temperature during the preparation of biochar has an impact on the biomass of the prepared soil remediation agent. The possible reason is that although increasing the combustion temperature in the early stage will reduce the organic matter content of the biochar itself, it will make the pores of the biochar larger, and more bacterial agents can be loaded during the compounding process with the bacterial agent, which is used to increase the final biomass. When the temperature reaches a certain critical point, a higher combustion temperature will consume the biomass in the biochar, ultimately leading to a decrease in the biomass entering the soil. Therefore, 850 °C is selected as the optimal combustion temperature.
[0061] Example 6
[0062] The preparation method and test method of this example are basically the same as those of Example 1, except that the impregnation time in step S2 is 24 hours.
[0063] Example 7
[0064] The preparation method and test method of this example are basically the same as those of Example 1, except that the impregnation time in step S2 is 48 hours.
[0065] The test results of the soil remediation agents prepared in Examples 1, 6, and 7 for soil remediation are shown in Table 4.
[0066] Table 4
[0067]
[0068]
[0069] It can be concluded from Table 4 that the impregnation time of biochar in the compound bacterial agent has a small impact on the finally prepared soil remediation agent, and its impact is mainly reflected in the index of the final biomass. The possible reason is that when the impregnation time is less than 36 hours, the compound bacterial agent fails to penetrate deeply into the pores of the biochar, resulting in insufficient loading of the bacterial agent, thus affecting the final biomass of the soil.
[0070] Example 8
[0071] The preparation method and test method of this example are basically the same as those of Example 1, except that the impregnation solution used in step S2 has been recycled 5 times.
[0072] Example 9
[0073] The preparation method and test method of this example are basically the same as those of Example 1, except that the impregnation solution used in step S2 has been recycled 10 times.
[0074] Example 10
[0075] The preparation method and testing method of this example are basically the same as those of Example 1, except that the impregnating solution used in step S2 has been recycled 15 times.
[0076] Example 11
[0077] The preparation method and testing method of this example are basically the same as those of Example 1, except that the impregnating solution used in step S2 has been recycled 20 times.
[0078] The soil remediation tests of the soil remediation agents prepared in Examples 1, 8, 9, 10, and 11 are shown in Table 5 as follows.
[0079] Table 5
[0080]
[0081]
[0082] It can be seen from Table 5 that after the impregnating solution is recycled more than 10 times, the effect of the soil remediation agent weakens as the number of impregnations increases. The possible reason is that after the number of impregnations is more than 10 times, the functional components in the composite bacterial agent are largely absorbed by the biochar, resulting in a decrease in the amount of effective components adsorbed by the subsequent biochar impregnation, which affects the use effect of the soil remediation agent.
[0083] Example 12
[0084] The preparation method and testing method of this example are basically the same as those of Example 1, except that the activation step described in S3 is not carried out.
[0085] Example 13
[0086] The preparation method and testing method of this example are basically the same as those of Example 1, except that the activation temperature in step S3 is 30 °C.
[0087] Example 14
[0088] The preparation method and testing method of this example are basically the same as those of Example 1, except that the activation temperature in step S3 is 40 °C.
[0089] Table 6
[0090]
[0091] It can be seen from Table 6 that the activation step has a great influence on the soil remediation agent, and its influence is mainly reflected in the final biomass and soil bulk density indicators. If the soil remediation agent is not activated or the activation temperature is not suitable, it is not conducive to the rapid growth and reproduction of microorganisms, thus affecting the final soil biomass and bulk density.
[0092] The foregoing basic example of the present application and its various further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in the present application. In the solution of the present application, each alternative example can be arbitrarily combined with any basic example and alternative example.
[0093] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. A preparation method of a mine soil remediation agent, characterized in that, It includes the following steps: S1. Obtain biochar by subjecting biochar raw materials to crushing pretreatment and high-temperature combustion; S2. Add the biochar to a liquid composite bacterial agent for impregnation; S3. Dry the biochar impregnated with the composite bacterial agent, and then carry out physical activation in an aerobic environment to obtain a mine soil remediation agent.
2. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, In the step S1, the biochar raw materials include wood, straw or tobacco waste.
3. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, In the step S1, the crushing pretreatment is specifically to crush the biochar raw materials into slag with a length ≤ 5 cm or a diameter ≤ 5 cm.
4. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, In the step S1, the high-temperature combustion temperature is 700 - 1000 °C, and the time is 2 - 4 hours.
5. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, In the step S2, the ratio of the biochar to the liquid composite bacterial agent is 1 g:5 mL, and the impregnation time is 36 - 48 hours.
6. The preparation method of a mine soil remediation agent according to claim 5, characterized in that, The composite bacterial agent includes Bacillus subtilis, Bacillus licheniformis, yeast and photosynthetic bacteria, and their ratio is Bacillus subtilis ≥ 45%, Bacillus licheniformis ≥ 30%, yeast 5% - 10% and photosynthetic bacteria 10% - 15%.
7. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, In the step S3, the drying temperature is 25 - 30 °C, and it is dried to a constant weight.
8. The preparation method of a mine soil remediation agent according to claim 1, characterized in that, The temperature of the physical activation is 30 - 40 °C, the activation time is 30 - 60 min, and the oxygen content is 15% - 30%.
9. A mine soil remediation agent, characterized in that, Prepared by the method described in any one of claims 1 - 8.