Effectiveness active management and control system for buffering type mining area downtime geological isolation

Abstract

The invention relates to the technical field of active control and guarantee of reliability and effectiveness of an isolation layer when a mining area or a quarry pit is used as a construction waste or industrial waste landfill and ecological harmful substances are isolated from an earth surface ecological restoration environment. The effective active management and control system for the geological isolation of the buffer type mining area downtime adopts the following steps: S10, arranging a CO2 strong adsorption material in a downtime filling area in a mixed manner; s20, spraying a switch-type Li salt culture medium and Li-sensitive actinomycetes at the position which is 1m thick on the upper surface of the isolation layer covering the adsorption layer, so as to form a Li salt buffer-type biological self-repairing isolation layer; by constructing a multi-layer isolation structure and combining with an advanced biological activity management and control method, the technology is guaranteed to skillfully cross an isolation preparation period, in a function implementation period, the isolation state is monitored in real time, maintenance and repair are carried out in time, meanwhile, damage threats of plant root systems to an isolation system are prevented, and the reliability and effectiveness of an isolation layer are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of active control and guarantee of the reliability and effectiveness of an isolation layer when utilizing a mining area or a quarry pit as a landfill for construction waste or industrial waste to isolate ecological hazards from a surface ecological restoration environment, and in particular to an active control system for the effectiveness of geological isolation of a buffer-type mining pit. Background Art

[0002] With the acceleration of urbanization and industrialization, the amount of construction waste and industrial waste generated has increased dramatically. How to dispose of these wastes scientifically and reasonably has become an environmental protection issue that needs to be urgently addressed.

[0003] Traditional landfills are no longer able to meet the growing demand for waste disposal due to limited land resources. Therefore, using abandoned mines or quarry pits as landfills has become an effective solution. This not only saves land resources, but also enables the secondary use of abandoned mines, which has important economic and environmental significance.

[0004] However, abandoned mining areas or quarry pits face many technical challenges as landfills. The primary issue is how to prevent the leakage of harmful substances in landfill waste and avoid contamination of the surface ecological restoration area. Traditional passive isolation measures such as single-layer impermeable membranes or clay layers are difficult to reliably isolate harmful substances for a long time and are prone to failure when encountering extreme weather or geological activities. Therefore, a reliable and effective active control technology is urgently needed to ensure the long-term effectiveness and stability of the isolation layer.

[0005] At present, a lot of research has been conducted at home and abroad on the geological isolation of solid waste landfills, and a variety of isolation measures and technical means have been proposed, mainly including multi-layer isolation structure design, anti-seepage material improvement, leakage monitoring system, etc. However, most of these measures rely on passive isolation, lack active control measures, and cannot respond to damage or failure of the isolation layer in real time. Summary of the invention

[0006] The purpose of the present invention is to provide an active management and control system for the effectiveness of buffer-type mining area pit geological isolation in view of the defects and shortcomings of the prior art.

[0007] The active control system for effectiveness of buffer-type mining area pit geological isolation described in the present invention adopts the following steps:

[0008] S10: Mix and arrange CO2 strong adsorption materials in the pit filling area;

[0009] S20: Spraying a switchable Li salt culture medium and Li-sensitive actinomycetes at a thickness of 1 meter on the upper surface of the isolation layer overlying the adsorption layer, thereby forming a Li salt buffered biological self-repairing isolation layer;

[0010] S30: Arrange a 5-10 meter thick porous inorganic material above the isolation layer and spray anaerobic CO2 absorbing bacteria to form a CO2 biological absorption layer;

[0011] S40: Arrange a covering soil layer on the CO2 biological absorption layer, and plant ground covers with well-developed creeping root systems and a taproot length of less than 1 meter during the ecological restoration process, thereby forming an ecological restoration layer;

[0012] S50: The three-layer structure of Li salt buffer biological self-repairing isolation layer, CO2 biological absorption layer and ecological restoration layer constitutes the isolation safety management and control system of the mine pit filling area.

[0013] Furthermore, when the pit filling area in step S10 is filled with ecologically hazardous wastes such as construction waste and domestic waste, it is necessary to add CO2 strong adsorption materials to make the area have certain CO2 preservation properties. CO2 will serve as a starting factor for active repair of isolation failure.

[0014] Furthermore, the Li salt buffered biological self-repairing isolation layer in step S20 is composed of isolation layer construction materials, switchable Li salt culture medium and Li-sensitive actinomycetes; and has the following functions:

[0015] A. At the beginning of the formation of the isolation layer, the material needs to go through a stable period to complete the closure of the cracks and gradually realize the isolation function. During this isolation preparation period, the bioremediation function is locked through Li salt control, forming a biological self-repair waiting period;

[0016] B. After the waiting period, the isolation layer enters the functional implementation period. If cracks appear at this time, CO2 will escape, and the biological self-repair function will be activated to complete the sealing of the cracks in the isolation layer.

[0017] Furthermore, the CO2 bio-absorption layer in step S30 is implemented by CO2 acetic acid bacteria, and this layer is combined with the surface CO2 escape plant capture layer to capture the escaped CO2;

[0018] In the CO2 bio-absorption layer, CO2 acetic acid bacteria produce bio-acetic acid under anaerobic conditions, and the regional pH level can reach 4.0-5.0; part of the acetic acid diffuses downward to the Li salt buffered biological self-repair isolation layer, acting as an acid-base balance regulator for the ecological environment of Li-sensitive actinomycetes;

[0019] Another part of the acetic acid rises and diffuses to the surface CO2 escape plant capture layer, serving as ecological nutrition for the surface soil; this layer of acetic acid environment also has the function of preventing the penetration of the roots of surface plants; thus, this layer has the dual effect of preventing CO2 from escaping downwards and preventing the penetration of roots upwards to destroy the isolation layer.

[0020] Furthermore, the ecological restoration layer in step S40 is the implementation layer of ecological restoration of the mining pit, and the thickness of the covering layer is determined according to the project resource volume, but the thickness of the covering layer should not be less than the average vertical length of the roots of the planned planted vegetation and the surrounding wild vegetation.

[0021] Furthermore, the switchable Li salt culture medium in step S20 initially contains a high concentration of Li2CO3, and the Li-sensitive actinomycetes cannot grow in a high Li2CO3 environment and are in a dormant state;

[0022] When cracks appear in the isolation of the CO2 adsorption pool, a large amount of adsorbed CO2 gas escapes. When passing through the Li salt buffered biological self-repairing isolation layer, CO2 hydrolyzes solid Li2CO3 into LiHCO3, and diffuses with the flow of surface water to achieve Li salt dilution. When the Li2CO3 content is less than 12g / L, the inhibition of Li2CO3 on the Li-sensitive actinomycetes in the CO2 adsorption pool is released. At the same time, with the help of the escaped CO2 supply, the Li-sensitive actinomycetes use CO2 as a carbon source and supplement N, P, K, and S elements with a switch-type Li salt culture medium in a low Li concentration state. The bacteria grow rapidly and gradually complete the crack plugging by biological expansion. With the implementation of crack plugging, the amount of CO2 escaped decreases. Under the limitation of C source, the Li-sensitive actinomycetes enter the inhibition state again, waiting for the arrival of the next high CO2 escape cycle.

[0023] Furthermore, the Li-sensitive actinomycetes in step S20 were first inhibited because the Li2CO3 environmental concentration was higher than the tolerance value, and then inhibited due to the limited supply of C source; in the process of changing from the inhibited state to the growing state, its growth characteristics are:

[0024] A. From the inhibited state to the growing state, it first undergoes a gradual acceleration of growth, and then gradually enters a balanced and stable growth process according to the growth curve and the actual CO2 supply rate. With the significant effect of fissure plugging, the CO2 supply decreases, and the bacteria are affected by the limited carbon source supply, and the growth rate slows down until the plugging is successful, CO2 escape is inhibited, and Li-sensitive actinomycetes enter a dormant state due to C source limitation;

[0025] B. At the same time, the changes in Li2CO3 content in the plugging surface and the abundance of Li-sensitive actinomycetes can be used to assess whether there have been undocumented plugging failures in the area. 8 / cm 2 In the technical implementation area, it is necessary to re-spray the switch type Li salt culture medium.

[0026] Furthermore, the Li-sensitive actinomycetes in step S20 are selected and cultivated from the soil of the local surrounding ruminant farms, and the specific method is as follows:

[0027] A. Based on the switchable Li salt culture medium formula, the Li2CO3 concentration was changed to form three Li gradient culture media with Li concentrations of 100%, 50%, and 10%, respectively, and mixed with sterile fine sand in a ratio of 1:1 to form a gel, which was then applied to the culture dish;

[0028] B. The surface of the culture medium gel was dotted into the soil around the farm, and placed in a CO2 incubator to cultivate soil Li-sensitive actinomycetes at 20°C;

[0029] C. Observe the growth of Li-sensitive actinomycetes around the soil under a microscope, select Li-sensitive actinomycetes that are inhibited at Li concentrations of 100% and 50% but are normally active at 10%, then select Li-sensitive actinomycetes using the streaking method, further cultivate them using the same method, and finally obtain the strains required by this patent.

[0030] Furthermore, the method for enriching and cultivating CO2 acetic acid bacteria from animal manure comprises the following steps:

[0031] A. Collect fresh animal manure samples from local farms;

[0032] B. Pre-treating the sample to remove large particles and prepare a suspension under sterile conditions; inoculating the pre-treated suspension into a culture medium containing a CO2 nutrient medium, wherein the pH value of the culture medium is between 6.0 and 7.5, and enriching and culturing the suspension in a CO2 incubator under anaerobic conditions for 5 to 7 days;

[0033] C. inoculating the culture fluid into a selective medium containing a high concentration of CO2 and acetic acid or other organic acid for selective culture;

[0034] D. diluting the culture solution in the selective culture medium using the dilution plate method, and spreading it on an agar medium containing an appropriate amount of CO2, and cultivating it in a CO2 incubator to select a single colony of acetic acid bacteria with CO2 nutritional characteristics; further purifying the selected single colony, and obtaining purified CO2-nutritional acetic acid bacteria through multiple streaking separation and amplification culture.

[0035] Furthermore, isolation autocoupling and repair are based on the basic condition of CO2 escape from the adsorption layer caused by isolation failure, and the inhibition-cultivation function of the switch-type Li salt culture medium on Li-sensitive actinomycetes is realized through the self-ablation of Li components in the switch-type Li salt culture medium constructed by the isolation facade by CO2; in order to prevent the impact of foreign bacteria on the local microecological system and to ensure the environmental adaptability of bacteria and soil ecological safety, this type of Li-sensitive actinomycetes must and can only be bred locally according to the method of this technology; according to the temperature characteristics, this type of Li-sensitive actinomycetes belongs to low-temperature Li-sensitive actinomycetes, and from the biochemical mechanism: the competition of Li-sensitive actinomycetes for CO2 is weaker than Li2CO3 hydrolysis, so when the CO2 concentration increases, the growth of actinomycetes can be better supported only after the Li2CO3 hydrolysis is completed.

[0036] The beneficial effects of the present invention are as follows: the effectiveness active management and control system of a buffer-type mining pit geological isolation described in the present invention constructs a multi-layer isolation structure and combines advanced biological activity management and control methods to ensure that the technology can cleverly transcend the isolation preparation period. During the function implementation period, the isolation status is monitored in real time, and maintenance and repair are carried out in a timely manner, while preventing the threat of damage to the isolation system by plant roots, thereby greatly improving the reliability and effectiveness of the isolation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application, but do not constitute an improper limitation of the present invention. In the drawings:

[0038] Figure 1 It is a schematic diagram of the technical implementation of the present invention;

[0039] Description of reference numerals:

[0040] 1. Dump filling area; 2. Isolation layer; 3. CO2 biological absorption layer; 4. Ecological restoration layer. DETAILED DESCRIPTION

[0041] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the illustrative embodiments and descriptions are only used to explain the present invention but are not intended to limit the present invention.

[0042] like Figure 1 As shown, the effectiveness active control system of a buffer-type mining area pit geological isolation described in this specific implementation manner adopts the following steps:

[0043] S10: mixing and arranging a certain amount of CO2 strong adsorption material in the pit filling area 1;

[0044] S20: spraying a switchable Li salt culture medium and Li-sensitive actinomycetes at a thickness of 1 meter on the upper surface of the isolation layer 2 overlying the adsorption layer, thereby forming a Li salt buffered biological self-repairing isolation layer 2-1;

[0045] S30: Arrange a 5-10 meter thick porous inorganic material above the isolation layer 2 and spray anaerobic CO2 absorbing bacteria to form a CO2 biological absorption layer 3;

[0046] S40: Arranging a covering soil layer on the CO2 biological absorption layer 3, and planting ground covers with a well-developed creeping root system and a taproot length of less than 1 meter during the ecological restoration process, thereby forming an ecological restoration layer 4;

[0047] S50: The three-layer structure of Li salt buffered biological self-repairing isolation layer 2-1, CO2 biological absorption layer 3, and ecological restoration layer 4 constitutes the isolation safety management and control system of the mine pit filling area.

[0048] Furthermore, when the pit filling area 1 in step S10 is filled with ecologically hazardous wastes such as construction waste and domestic waste, a certain amount of CO2 strong adsorption material needs to be added to make the area have certain CO2 preservation properties. CO2 will serve as a starting factor for active repair of isolation failure.

[0049] Furthermore, the Li salt buffered biological self-repairing isolation layer 2-1 in step S20 is composed of isolation layer 2 construction materials, switchable Li salt culture medium and Li-sensitive actinomycetes; and has the following functions:

[0050] A. At the beginning of the formation of the isolation layer 2, the material needs to go through a stable period to complete the closure of the cracks and gradually realize the isolation function. During this isolation preparation period, the bioremediation function is locked through Li salt control, forming a biological self-repair waiting period;

[0051] B. After the waiting period, isolation layer 2 enters the function implementation period. If cracks appear at this time, CO2 will escape, and the biological self-repair function will be activated to complete the sealing of the cracks in isolation layer 2.

[0052] Furthermore, the CO2 bio-absorption layer 3 in step S30 is implemented by CO2 acetic acid bacteria, and this layer is combined with the surface CO2 escape plant capture layer to achieve the capture of escaped CO2;

[0053] In the CO2 bio-absorption layer 3, CO2 acetic acid bacteria produce bio-acetic acid under anaerobic conditions, and the regional pH level can reach 4.0-5.0; part of the acetic acid diffuses downward to the Li salt buffered biological self-repair isolation layer 2-1, serving as an acid-base balance regulator for the ecological environment of Li-sensitive actinomycetes;

[0054] Another part of the acetic acid rises and diffuses to the surface CO2 escape plant capture layer, serving as ecological nutrition for the surface soil; this layer of acetic acid environment also has the function of preventing the penetration of the roots of surface plants; thus, this layer has the dual effect of preventing CO2 from escaping downwards and preventing the penetration of roots upwards to destroy the isolation layer 2.

[0055] Furthermore, the ecological restoration layer 4 in step S40 is the implementation layer for ecological restoration of the mining pit, and the thickness of the covering soil layer is determined according to the project resource quantity, but the thickness of the covering soil layer should not be less than the average vertical length of the roots of the planned planted vegetation and the surrounding wild vegetation.

[0056] Furthermore, the switchable Li salt culture medium in step S20 initially contains a high concentration of Li2CO3, and the Li-sensitive actinomycetes cannot grow in a high Li2CO3 environment and are in a dormant state;

[0057] When cracks appear in the isolation of the CO2 adsorption pool, a large amount of adsorbed CO2 gas escapes. When passing through the Li salt buffered biological self-repairing isolation layer 2-1, CO2 hydrolyzes solid Li2CO3 into LiHCO3, and diffuses with the flow of surface water to achieve Li salt dilution. When the Li2CO3 content is less than 12g / L, the inhibition of Li2CO3 on the Li-sensitive actinomycetes in the CO2 adsorption pool is released. At the same time, with the help of the escaped CO2 supply, the Li-sensitive actinomycetes use CO2 as a carbon source, supplemented by a switch-type Li salt culture medium in a low Li concentration state to supplement N, P, K, and S elements. The bacteria grow rapidly and gradually complete the crack plugging by biological expansion. With the implementation of crack plugging, the amount of CO2 escaped decreases. Under the limitation of C source, the Li-sensitive actinomycetes enter the inhibition state again, waiting for the arrival of the next high CO2 escape cycle.

[0058] Furthermore, the Li-sensitive actinomycetes in step S20 were first inhibited because the Li2CO3 environmental concentration was higher than the tolerance value, and then inhibited due to the limited supply of C source; in the process of changing from the inhibited state to the growing state, its growth characteristics are:

[0059] A. From the inhibited state to the growing state, it first undergoes a gradual acceleration of growth, and then gradually enters a balanced and stable growth process according to the growth curve and the actual CO2 supply rate. With the significant effect of fissure plugging, the CO2 supply decreases, and the bacteria are affected by the limited carbon source supply, and the growth rate slows down until the plugging is successful, CO2 escape is inhibited, and Li-sensitive actinomycetes enter a dormant state due to C source limitation;

[0060] B. At the same time, the changes in Li2CO3 content in the plugging surface and the abundance of Li-sensitive actinomycetes can be used to assess whether there have been undocumented plugging failures in the area. 8 / cm 2In the technical implementation area, it is necessary to re-spray the switch type Li salt culture medium.

[0061] Furthermore, the Li-sensitive actinomycetes in step S20 are selected and cultivated from the soil of the local surrounding ruminant farms, and the specific method is as follows:

[0062] A. Based on the switchable Li salt culture medium formula, the Li2CO3 concentration was changed to form three Li gradient culture media with Li concentrations of 100%, 50%, and 10%, respectively, and mixed with sterile fine sand in a ratio of 1:1 to form a gel, which was then applied to the culture dish;

[0063] B. The surface of the culture medium gel was dotted into the soil around the farm, and placed in a CO2 incubator to cultivate soil Li-sensitive actinomycetes at 20°C;

[0064] C. Observe the growth of Li-sensitive actinomycetes around the soil under a microscope, select Li-sensitive actinomycetes that are inhibited at Li concentrations of 100% and 50% but are normally active at 10%, then select Li-sensitive actinomycetes using the streaking method, further cultivate them using the same method, and finally obtain the strains required by this patent.

[0065] Furthermore, the method for enriching and cultivating CO2 acetic acid bacteria from animal manure comprises the following steps:

[0066] A. Collect fresh animal manure samples from local farms;

[0067] B. Pre-treating the sample to remove large particles and prepare a suspension under sterile conditions; inoculating the pre-treated suspension into a culture medium containing a CO2 nutrient medium, wherein the pH value of the culture medium is between 6.0 and 7.5, and enriching and culturing the suspension in a CO2 incubator under anaerobic conditions for 5 to 7 days;

[0068] C. inoculating the culture fluid into a selective medium containing a high concentration of CO2 and acetic acid or other organic acid for selective culture;

[0069] D. diluting the culture solution in the selective culture medium using the dilution plate method, and spreading it on an agar medium containing an appropriate amount of CO2, and cultivating it in a CO2 incubator to select a single colony of acetic acid bacteria with CO2 nutritional characteristics; further purifying the selected single colony, and obtaining purified CO2-nutritional acetic acid bacteria through multiple streaking separation and amplification culture.

[0070] Furthermore, the isolation autocoupling and repair are based on the basic condition of CO2 escape from the adsorption layer caused by isolation failure, and the inhibition-cultivation function of the switch-type Li salt culture medium on Li-sensitive actinomycetes is realized through the self-ablation of Li components in the switch-type Li salt culture medium constructed by the isolation facade by CO2; in order to prevent the impact of foreign bacteria on the local microecological system and to ensure the environmental adaptability of bacteria and soil ecological safety, this type of Li-sensitive actinomycetes must and can only be bred locally according to the method of claim 4; according to the temperature characteristics, this type of Li-sensitive actinomycetes belongs to low-temperature Li-sensitive actinomycetes, and from the biochemical mechanism: the competition of Li-sensitive actinomycetes for CO2 is weaker than Li2CO3 hydrolysis, so when the CO2 concentration increases, the growth of actinomycetes can be better supported only after the Li2CO3 hydrolysis is completed. Specific embodiment one:

[0072] A mine pit needs to be filled with construction waste and ecologically restored. Construction waste has alkaline characteristics and poses a potential threat to the healthy growth of surface vegetation. In order to effectively isolate harmful substances, weaken the threat of alkaline substances spreading to plant roots, and achieve long-term ecological restoration, a buffer-type active control technology for the effectiveness of geological isolation of mine pits was adopted.

[0073] 1. Material preparation

[0074] (1) CO2 strong adsorption material: In this case, zeolite was selected as the CO2 strong adsorption material. When the construction waste was landfilled, 1% of the zeolite raw material that was saturated with CO2 was added.

[0075] (2) Switchable Li salt culture medium: contains high concentration of Li2CO3, with an initial concentration of 100 g / L. The culture medium formula is shown in Table 1.

[0076] Table 1 Switchable Li salt culture medium composition

[0077] Type of culture medium Quality Ratio <![CDATA[Li2CO3]]> 100g / L <![CDATA[(NH4)2SO4]]> 20g / L <![CDATA[KH2PO4]]> 0.8g / L <![CDATA[K2HPO4]]> 0.5g / L <![CDATA[FeSO4]]> 0.25g / L NaCl 0.64g / L

[0078] (3) Li-sensitive actinomycetes: selected and bred from the soil of local ruminant farms. The culture medium formula used for breeding is shown in Table 2.

[0079] The specific method is: based on the switchable Li salt culture medium formula, the Li2CO3 concentration is changed to form three Li gradient culture media, with Li concentrations of 100%, 50%, and 10%, respectively, and mixed with sterile fine sand in a 1:1 ratio to form a gel, which is then applied to the culture dish.

[0080] 1 kg of surface soil was sampled from the surrounding area of ​​the farm, large stones and other impurities were removed, the soil was dried to a moisture content of 30%, and the soil was coarsely ground through a 20-mesh sieve and mixed.

[0081] Dot an appropriate amount of soil from the surrounding area of ​​the farm onto the surface of the culture medium gel, 5-10 spots per culture dish.

[0082] The culture medium was placed in a CO2 incubator at 20°C for cultivation of soil Li-sensitive actinomycetes.

[0083] The growth of actinomycetes around the soil was observed under a microscope every 12 hours, and the actinomycetes that were inhibited in the 100% and 50% Li2CO3 concentration switch-type Li salt culture medium samples but grew rapidly in the 10% sample were selected as Li-sensitive actinomycetes, and then further cultivated using the same method to finally obtain the strain required by this patent.

[0084] Table 2 The composition of the culture medium used for breeding with the switchable Li salt culture medium as reference

[0085]

[0086]

[0087] (4) Anaerobic CO2 absorbing bacteria: CO2 nutrient-type acetic acid bacteria enriched from local animal manure are used, and the culture medium used is the same as that of the conventional bacteria.

[0088] The specific method is as follows: collect fresh animal manure samples from local farms;

[0089] The sample is pretreated to remove large particle impurities and prepared into a suspension under sterile conditions;

[0090] The pretreated suspension is inoculated into a CO2-containing nutrient acetic acid bacteria culture medium, the pH value of the culture medium is between 6.0 and 7.5, and is enriched and cultured in a CO2 incubator under anaerobic conditions for 5 to 7 days;

[0091] The culture solution is inoculated into a selective medium containing high concentrations of CO2 and acetic acid for selective culture;

[0092] The culture solution in the selective medium is diluted using the dilution plate method and spread on an agar medium containing an appropriate amount of CO2 to select single colonies of acetic acid bacteria with CO2 nutritional characteristics;

[0093] The selected single colonies are further purified and purified CO2-trophic acetic acid bacteria are obtained through multiple streaking isolation and amplification culture.

[0094] Table 2 CO2 nutrient type acetic acid bacteria culture medium composition table

[0095] Medium type Quality Ratio <![CDATA[(NH4)2SO4]]> 20g / L <![CDATA[KH 2 PO4]]> 0.8g / L <![CDATA[K2HPO4]]> 1.5g / L <![CDATA[MgSO4·7H2O]]> 0.5g / L NaCl 0.2g / L

[0096] (5) Porous inorganic material: Natural pumice with a particle size of 10-20 cm was selected.

[0097] (6) Vegetation: Select ground cover with a well-developed creeping root system and a taproot length of less than 1 meter. Plants from the Poaceae, Cyperaceae, Convolvulaceae, Leguminosae, Amaranthaceae, Asteraceae, etc. can be selected. In this embodiment, the following plants are selected: Cynodon dactylon, Sedum sphenanthera, Saxifraga sphenanthera, and Schisandra chinensis.

[0098] 2. Construction steps

[0099] (1) Preparation of the pit filling area (1): Landfill construction waste, domestic waste and other ecologically harmful waste. Mix a certain amount of pre-adsorbed CO2 strong adsorption material (zeolite) in a ratio of 100:1 to ensure that the area has CO2 storage properties. After filling, re-inject CO2 to enhance the zeolite adsorption capacity.

[0100] (2) Formation of biological self-repairing isolation layer (2): Cover the filling area with a 3-meter-thick isolation layer (2), using a stable material with crack closure function (such as foamed cement, high-viscosity clay composite sealing material, etc.). Mix the 1-meter-thick layer on the upper surface of the isolation layer (2) in a ratio of 5:1, and spray Li-sensitive actinomycetes on the surface (coverage rate reaches 10 6 / cm 2 ) to form a Li salt buffered biological self-repairing isolation layer (2-1).

[0101] (3) Construction of CO2 biological absorption layer (3): 7 meters thick natural pumice particles were laid on the isolation layer (2). CO2 nutrient acetic acid bacteria culture medium was sprayed (the amount of culture medium sprayed was calculated based on the final moisture content, and the moisture content reached 35%), and anaerobic CO2 nutrient acetic acid bacteria were sprayed simultaneously (the coverage rate reached 10 5 / cm 3 ), forming a CO2 biological absorption layer (3).

[0102] (4) Implementation of the ecological restoration layer (4): Lay a 0.5-meter-thick topsoil on the CO2 biological absorption layer (3) to form an ecological restoration soil layer; randomly sow seeds of plants such as Cynodon dactylon, Sedum sphenanthera, Saxifraga sphenanthera, and Cynoglossum sphenanthera (sowing rate per unit area: 5 kg / mu) to form an ecological restoration layer (4).

[0103] 3. Monitoring and maintenance

[0104] (1) Monitoring of the isolation layer (2): Monitor the culture medium consumption and the growth of Li-sensitive actinomycetes in the Li-salt buffered biological self-repair isolation layer (2-1) every six months. Based on the changes in the Li2CO3 content in the plugging surface and the changes in the abundance of Li-sensitive actinomycetes, assess whether there have been undocumented plugging failures in the area. 8 / cm 2 In the technical implementation area, it is necessary to re-spray the switch type Li salt culture medium.

[0105] (2) Maintenance of the CO2 bio-absorption layer (3): The pH value and acetic acid concentration of the CO2 bio-absorption layer (3) were tested every six months to ensure the activity of CO2 acetic acid bacteria. 8 / cm 2 In the technical implementation area, it is necessary to simultaneously supplement the CO2-nutrient acetic acid bacteria culture medium in the area to ensure the stability of the ecological restoration layer (4).

[0106] (3) Observation of the effect of surface ecological restoration: Test the soil pH every month and monitor the soil acid-base balance in the ecological restoration area. Observe vegetation growth from time to time, especially pay attention to small areas with slow or sparse vegetation growth, and use them as isolation safety assessment areas for intensified management and control, and monitor the surface CO2 escape to evaluate the effectiveness of the isolation area. For isolation failures that cannot be blocked in time by this technology, other technical solutions should be used to cooperate with blocking to ensure its safety.

[0107] The effective active control technology of buffer-type mining area pit geological isolation provided by the present invention has the following advantages:

[0108] Beneficial effects:

[0109] (1) Improve the reliability and effectiveness of the isolation layer (2): By mixing and arranging CO2 strong adsorption materials in the filling area of ​​the mine pit, using CO2 as the starting factor, and relying on the sensitivity of the switchable lithium salt culture medium to CO2 and the inhibitory effect on the bacteria, a programmed active isolation layer (2) effectiveness control technology is constructed. On the one hand, it ensures that every biological nutrient can be used effectively, and on the other hand, it uses the sensitivity of the organisms to environmental changes to achieve crack plugging when the isolation fails. The patented technology can effectively prevent the leakage of harmful substances and ensure the long-term stability and reliability of the isolation layer (2).

[0110] (2) Ecological restoration support: Arrange a covering soil layer on the CO2 biological absorption layer (3), and plant ground covers with well-developed creeping roots and a taproot length of less than 1 meter. With the help of a stable isolation layer (2), the surface ecological restoration is ensured. At the same time, the biological acidity of the CO2 biological absorption layer (3) is used to simultaneously control the threat of surface vegetation roots to the isolation layer (2). This not only helps the ecological restoration of the mine pit, but also ensures sustainable vegetation development, improves the ecological environment, and forms a complete ecosystem.

[0111] (3) Multi-layer structure comprehensive protection: This patented technology constructs a mine pit filling area isolation safety management and control system through the comprehensive application of multi-layer isolation structure and biological restoration layer. This system can not only effectively prevent the leakage of harmful substances and the escape of CO2, but also achieve the comprehensive effect of ecological restoration and environmental protection.

[0112] (4) Environmental adaptability and safety: By enriching and cultivating CO2-trophic acetic acid bacteria and Li-sensitive actinomycetes from local animal manure, the environmental adaptability of the strains and the soil ecological safety are ensured, avoiding the potential harm of foreign strains to the local ecological environment.

[0113] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. An active control system for effectiveness of buffer-type mining area pit geological isolation, characterized by: Use the following steps: S10: mixing and arranging CO2 strong adsorption materials in the pit filling area (1); S20: spraying a switchable Li salt culture medium and Li-sensitive actinomycetes at a thickness of 1 meter on the upper surface of the isolation layer (2) overlying the adsorption layer, thereby forming a Li salt buffered biological self-repairing isolation layer (2-1); S30: arranging a 5-10 meter thick porous inorganic material above the isolation layer (2) and spraying anaerobic CO2 absorbing bacteria to form a CO2 biological absorption layer (3); S40: Arranging a covering soil layer on the CO2 biological absorption layer (3), and planting ground covers with a well-developed creeping root system and a taproot length of less than 1 meter during the ecological restoration process, thereby forming an ecological restoration layer (4); S50: The three-layer structure of the Li salt buffer biological self-repairing isolation layer (2-1), the CO2 biological absorption layer (3), and the ecological restoration layer (4) constitutes the isolation safety management and control system of the mine pit filling area.

2. The effectiveness active management and control system of a buffer-type mining area pit geological isolation according to claim 1 is characterized by: When the pit filling area (1) in step S10 is filled with ecologically hazardous wastes such as construction waste and domestic waste, it is necessary to add CO2 strong adsorption materials to make the area have certain CO2 preservation properties. CO2 will serve as a starting factor for active repair of isolation failure.

3. The effectiveness active management and control system of a buffer-type mining area pit geological isolation according to claim 1 is characterized by: The Li salt buffered biological self-repairing isolation layer (2-1) in step S20 is composed of isolation layer (2) construction materials, switchable Li salt culture medium and Li-sensitive actinomycetes; and has the following functions: A. At the beginning of the formation of the isolation layer (2), the material needs to go through a stable period to complete the closure of the cracks and gradually realize the isolation function. During this isolation preparation period, the bioremediation function is locked through Li salt control, forming a biological self-repair waiting period; B. After the waiting period, the isolation layer (2) enters the functional implementation period. If cracks appear at this time, CO2 will escape, and the biological self-repair function will be activated to complete the sealing of the cracks in the isolation layer (2).

4. The effectiveness active management and control system of a buffer-type mining area pit geological isolation according to claim 1 is characterized by: The CO2 bio-absorption layer (3) in step S30 is realized by CO2 acetic acid bacteria, and this layer is combined with the surface CO2 escape plant capture layer to realize the capture of escaped CO2; in the CO2 bio-absorption layer (3), CO2 acetic acid bacteria produce biological acetic acid under anaerobic conditions, and the regional pH level can reach 4.0-5.0; part of the acetic acid diffuses downward to the Li salt buffered biological self-repair isolation layer (2-1), serving as an acid-base balance regulator for the ecological environment of Li-sensitive actinomycetes; Another part of the acetic acid rises and diffuses to the surface CO2 escape plant capture layer, serving as ecological nutrition for the surface soil; this layer of acetic acid environment also has the function of preventing the penetration of the roots of surface plants; thus, this layer has the dual effect of preventing CO2 from escaping downwards and preventing the roots from penetrating upwards and destroying the isolation layer (2).

5. The effectiveness active management and control system of a buffer-type mining area pit geological isolation according to claim 1 is characterized by: The ecological restoration layer (4) in step S40 is the implementation layer for ecological restoration of the mining pit. The thickness of the covering soil layer is determined according to the project resource volume, but the thickness of the covering soil layer should not be less than the average vertical length of the roots of the planned planted vegetation and the surrounding wild vegetation.

6. The effectiveness active management and control system of a buffer-type mining area pit geological isolation according to claim 1 is characterized by: The switchable Li salt culture medium in step S20 initially contains a high concentration of Li2CO3, and the Li-sensitive actinomycetes cannot grow in a high Li2CO3 environment and are in a dormant state; When cracks appear in the isolation of the CO2 adsorption pool, a large amount of adsorbed CO2 gas escapes. When passing through the Li salt buffered biological self-repairing isolation layer (2-1), CO2 hydrolyzes solid Li2CO3 into LiHCO3, and diffuses with the flow of surface water to achieve Li salt dilution; when the Li2CO3 content is less than 12g / L, the inhibition of Li2CO3 on the Li-sensitive actinomycetes in the CO2 adsorption pool is released. At the same time, with the help of the escaped CO2 supply, the Li-sensitive actinomycetes use CO2 as a carbon source, supplemented by a switch-type Li salt culture medium in a low Li concentration state to supplement N, P, K, and S elements, and the bacteria grow rapidly, and the cracks are gradually sealed by biological expansion; with the implementation of crack sealing, the amount of CO2 escaped decreases, and under the limitation of the C source, the Li-sensitive actinomycetes enter the inhibition state again, waiting for the arrival of the next high CO2 escape cycle.

7. The effectiveness active management and control system of buffer-type mining area pit geological isolation according to claim 1 is characterized by: The Li-sensitive actinomycetes in step S20 are first inhibited because the Li2CO3 environmental concentration is higher than the tolerance value, and then inhibited due to the limited supply of C source; in the process of changing from the inhibited state to the growing state, its growth characteristics are: A . From the inhibited state to the growth state, it first undergoes a gradual acceleration of growth, and then gradually enters a balanced and stable growth process according to the growth curve and the actual CO2 supply rate. With the significant effect of fissure plugging, the CO2 supply decreases, and the bacteria are affected by the limited carbon source supply, and the growth rate slows down until the plugging is successful, CO2 escape is inhibited, and Li-sensitive actinomycetes enter a dormant state due to C source limitation; B. At the same time, the changes in Li2CO3 content in the plugging surface and the abundance of Li-sensitive actinomycetes can be used to assess whether there have been undocumented plugging failures in the area. 8 / cm 2 In the technical implementation area, the switch type Li salt culture medium needs to be sprayed again.

8. The effectiveness active management and control system of buffer-type mining area pit geological isolation according to claim 1 is characterized by: The Li-sensitive actinomycetes in step S20 are selected and cultivated from the soil of the local ruminant farms, and the specific method is as follows: A. Based on the switchable Li salt culture medium formula, the Li2CO3 concentration was changed to form three Li gradient culture media with Li concentrations of 100%, 50%, and 10%, respectively, and mixed with sterile fine sand in a ratio of 1:1 to form a gel, which was then applied to the culture dish; B. The surface of the culture medium gel was dotted into the soil around the farm, and placed in a CO2 incubator to cultivate soil Li-sensitive actinomycetes at 20°C; C. Observe the growth of Li-sensitive actinomycetes around the soil under a microscope, select Li-sensitive actinomycetes that are inhibited at Li concentrations of 100% and 50% but are normally active at 10%, then select Li-sensitive actinomycetes using the streaking method, further cultivate them using the same method, and finally obtain the strains required by this patent.

9. The effectiveness active management and control system of buffer-type mining area pit geological isolation according to claim 4 is characterized by: The method for enriching and cultivating CO2 acetic acid bacteria from animal manure comprises the following steps: A. Collect fresh animal manure samples from local farms; B. Pre-treating the sample to remove large particles and prepare a suspension under sterile conditions; inoculating the pre-treated suspension into a culture medium containing a CO2 nutrient medium, wherein the pH value of the culture medium is between 6.0 and 7.5, and enriching and culturing the suspension in a CO2 incubator under anaerobic conditions for 5 to 7 days; C. inoculating the culture fluid into a selective medium containing a high concentration of CO2 and acetic acid or other organic acid for selective culture; D. diluting the culture solution in the selective culture medium using the dilution plate method, and spreading it on an agar medium containing an appropriate amount of CO2, and cultivating it in a CO2 incubator to select a single colony of acetic acid bacteria with CO2 nutritional characteristics; further purifying the selected single colony, and obtaining purified CO2-nutritional acetic acid bacteria through multiple streaking separation and amplification culture.

10. The effectiveness active management and control system of buffer-type mining area pit geological isolation according to claim 1 is characterized by: Isolation autocoupling and repair are based on the basic condition of CO2 escape from the adsorption layer caused by isolation failure. The inhibition-cultivation function of the switch-type Li salt culture medium on Li-sensitive actinomycetes is achieved through the self-ablation of Li components in the switch-type Li salt culture medium constructed by the isolation facade by CO2. In order to prevent the impact of foreign bacteria on the local microecological system and ensure the environmental adaptability of bacteria and soil ecological safety, this type of Li-sensitive actinomycetes must and can only be bred locally according to the method in this technology. According to the temperature characteristics, this type of Li-sensitive actinomycetes belongs to low-temperature Li-sensitive actinomycetes, and from the biochemical mechanism: the competition of Li-sensitive actinomycetes for CO2 is weaker than that of Li2CO3 hydrolysis. Therefore, when the CO2 concentration increases, the growth of actinomycetes can be better supported only after the hydrolysis of Li2CO3 is completed.

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