Method for improving tailings using sphaerulysin-related soil proteins

Abstract

The present application relates to the field of tailings ecological restoration, and more particularly to a method for improving tailings by using glomalin-related soil protein, wherein a glomalin-related soil protein solution is extracted from soil and externally applied to vanadium-titanium magnetite tailings in which alfalfa is planted, the content of alkaline hydrolysis nitrogen and available phosphorus in the vanadium-titanium magnetite tailings is significantly increased, the activity of heavy metals Cu and Cd is reduced, the growth of alfalfa is promoted, and the glomalin-related soil protein can be used as a new type of modifier to repair tailings.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tailings ecological restoration, and particularly relates to a method for improving tailings by using glomalin related soil protein. BACKGROUND

[0002] Glomalin related soil protein (GRSP) is a specific protein secreted by arbuscular mycorrhizal fungi (AMF), which is mainly produced on the surface of AMF hyphae extending into the soil. When the hyphae die, GRSP can fall off from the surface of the hyphae into the rhizosphere soil, and then affect the soil environment. Studies have found that glomalin related soil protein has high affinity for heavy metals, and contains 3%-5% N and 0.03%-0.1% P, and exists in large quantities in the soil.

[0003] China is rich in mineral resources, and a large amount of tailings will be produced in the process of mineral separation and sorting operation. The storage of tailings not only occupies a large amount of land, but also the heavy metals in the tailings can penetrate out through leaching, weathering and other actions, and can be enriched in the human body through the food chain. Long-term low-dose intake of rare earths has toxicity to human organs, endocrine and immune function, etc.

[0004] At present, domestic and foreign scholars mainly focus on physical restoration, chemical restoration, biological restoration and combined restoration in the ecological restoration of mined mines. The cost of chemical restoration and physical restoration of the mining area alone is high, and secondary pollution is easy to occur. The biological restoration of the mining area while taking into account the chemical and physical restoration has become a research hotspot in recent years.

[0005] The research on tailings ecological restoration technology has become an important content in the field of ecological environment protection. For example, the method for preparing artificial soil by using tailings in the patent application No. 202110003197.4 uses copper tailings as the main raw material, and then adds sugarcane residue fiber, low-alkali cement, pellet promoting agent, drought-resistant water-retaining agent, acidity regulator, microbial fertilizer and the like to modify the copper tailings, so that the copper tailings have the physical and chemical properties and nutrient components required for plant growth. For another example, the ecological restoration agent for tailings heavy metal contaminated soil in the patent No. 201610241203.9 uses rice husk, chicken manure and bone meal as raw materials, and the materials are prepared after mixing, pyrolysis and activation The filter cake obtained by mixing chitosan solution and bentonite suspension and then filtering is processed to prepare the material The material and the material are mixed to prepare the ecological restoration agent, which can reduce the dissolution of heavy metals, reduce the biological availability and harmful toxicity of the heavy metals, and reduce the migration and enrichment of the heavy metals in the ecological chain.

[0006] At present, the ecological restoration of tailings is mostly carried out by covering soil and improving matrix, which has problems of high cost, secondary pollution, poor effect of heavy metal improvement, and poor persistence. SUMMARY

[0007] In order to solve the above technical problems in the prior art, the application provides a method for improving tailings by using sphaerimyxin-related soil protein.

[0008] One of the purposes of the present application is to provide a method for improving the physicochemical properties of vanadium-titanium magnetite tailings by using sphaerimyxin-related soil protein. After applying sphaerimyxin-related soil protein to the vanadium-titanium magnetite tailings, the content of available nitrogen, available phosphorus and organic matter in the vanadium-titanium magnetite tailings is increased, thereby promoting the growth of alfalfa and increasing its biomass.

[0009] The second purpose of the present application is to provide a method for passivating the activity of heavy metals in vanadium-titanium magnetite tailings by using sphaerimyxin-related soil protein.

[0010] To achieve this technical purpose, the application adopts the following scheme: a method for improving tailings by using sphaerimyxin-related soil protein. Sphaerimyxin-related soil protein extracted from farmland near a vanadium-titanium magnetite tailings pond is applied exogenously to vanadium-titanium magnetite tailings where alfalfa is planted.

[0011] Compared with the prior art, the present application has the following advantages:

[0012] (1) The sphaerimyxin-related soil protein is extracted from soil 1.26 km southwest of the vanadium-titanium magnetite tailings pond, so the raw material is easy to obtain and the treatment method is environmentally friendly.

[0013] (2) The sphaerimyxin-related soil protein extract is applied to the vanadium-titanium magnetite tailings to passivate the heavy metals in the vanadium-titanium magnetite tailings and increase the nutrient content of the vanadium-titanium magnetite tailings.

[0014] The preferred scheme of the present application is:

[0015] After the alfalfa is planted on the vanadium-titanium magnetite tailings for 2 weeks, the sphaerimyxin-related soil protein is uniformly applied to the vanadium-titanium magnetite tailings, at which time the alfalfa has grown 3 leaves and the growth has entered a stable stage.

[0016] The sphaerimyxin-related soil protein is applied every 2 weeks thereafter to ensure that the sphaerimyxin-related soil protein can fully play a role in the vanadium-titanium magnetite tailings.

[0017] The sphaerimyxin-related soil protein is applied in the form of sphaerimyxin-related soil protein extract or semi-concentrated extract, and the concentration of the sphaerimyxin-related soil protein extract is 0.026 mg•ml -1 .

[0018] The spheroidin-related soil protein is extracted from the farmland soil 1.26 km southwest of a vanadium-titanium magnetite tailing pond, so as to ensure that the soil is similar to the vanadium-titanium magnetite tailing, and reduce uncertain factors. A sodium citrate solution is added, and the extraction is carried out at 121 ℃ and 0.1 MPa for 60 min. After cooling to room temperature, centrifugation is carried out at 6000 r / min for 5 min. The brownish red supernatant is taken. The same amount of sodium citrate solution is added to the centrifuge tube, and the supernatant is repeatedly extracted until the brownish red color of the supernatant disappears. The supernatants are combined to obtain the spheroidin-related soil protein extract, which is stored at 4 ℃ for use.

[0019] The dosage ratio of the soil and the sodium citrate solution is 1 g:8 ml, which is mixed in a 50 ml centrifuge tube. The concentration of the sodium citrate solution is 50 mmol / L, and the pH is 8. DETAILED DESCRIPTION

[0020] In order to fully understand the purpose, features and effects of the present application, the following specific embodiments are used to describe the present application in detail, but the present application is not limited to this.

[0021] Example 1

[0022] (1) Artificial simulation of vanadium-titanium magnetite tailing contaminated by different concentrations of copper: 100 mg / kg of Cu is added to the vanadium-titanium magnetite tailing and balanced for one month, which is recorded as Cu-100.

[0023] (2) Preparation of GRSP extract (the spheroidin-related soil protein used is obtained from a farmland 1.26 km southwest of a vanadium-titanium magnetite tailing pond, and is separated according to the method of Wright and Upadhyaya (1998)):

[0024] a) The soil between the depths of 0-20 cm in the farmland near the vanadium-titanium magnetite tailing is taken, mixed uniformly, and dried in a cool and ventilated place for use.

[0025] b) 1.00 g of the dried soil is weighed into a 50 ml centrifuge tube, 8 ml of a 50 mmol / L sodium citrate solution with pH 8.0 is added to the centrifuge tube, and the mixture is shaken uniformly. The extraction is carried out at 121 ℃ and 0.1 MPa for 60 min. After cooling to room temperature, centrifugation is carried out at 6000 r / min for 5 min, and the brownish red supernatant is taken. The same amount of sodium citrate solution is added to the centrifuge tube, and the extraction-cooling-centrifugation-liquid taking operation is repeated until the brownish red color of the supernatant disappears (7 times). The supernatants obtained in each time are mixed to obtain the spheroidin-related soil protein extract, which is stored at 4 ℃.

[0026] c) After obtaining the extract of glomalin-related soil protein, 0.1 mol / L hydrochloric acid solution was added until the pH was reduced to 2-2.5, ice bath for 60 min, 6000 r / min centrifugation for 4 min, remove the supernatant, add 0.1 mol / L NaOH solution to the precipitate until the precipitate is completely dissolved and adjust the pH to 7-7.5.

[0027] d) The concentration of the obtained glomalin-related soil protein extract was determined, and the content of glomalin-related soil protein was 0.026 mg•ml -1 .

[0028] (3) Test site:

[0029] The test was carried out in the greenhouse of Huazhong University of Science and Technology.

[0030] Select uniform size and plump seeds of Medicago sativa, surface sterilize with 10% H2O2 for 10 min, rinse with deionized water, and germinate in a biochemical incubator at 25°C until the seeds germinate. Vanadium titanium magnetite tailings substrate (basic physical and chemical properties see Table 1) was sterilized by steam (121°C, 0.14 Mpa, 2 h) and placed in experimental pots. Each pot contains 1 kg of vanadium titanium magnetite tailings, and 100 seeds of Medicago sativa are planted.

[0031] Table 1. Basic physical and chemical properties of vanadium titanium magnetite tailings

[0032]

[0033] (4) Test statistical indicators:

[0034] After the improved vanadium titanium magnetite tailings are passed through a 20 mesh sieve, diethylenetriamine pentaacetic acid (C 14 H 23 N3O 10 , DTPA) extraction method is used to extract available heavy metal Cu in vanadium titanium magnetite tailings, and alkali hydrolysis diffusion method is used to measure the content of alkali hydrolysis nitrogen in vanadium titanium magnetite tailings, and sodium bicarbonate extraction method is used to measure the content of available phosphorus in vanadium titanium magnetite tailings.

[0035] (5) Test group design:

[0036] The test group is divided into 4 groups, each group has 3 parallel tests, and the specific test group design is as follows:

[0037] Test group 1: zero strength of exogenous total extract glomalin-related soil protein extract as control, recorded as CK;

[0038] Test group 2: 10 ml of exogenous total extract glomalin-related soil protein extract, recorded as A;

[0039] Test group 3: 20 ml of exogenous total extracted glomalin-related soil protein extract, recorded as B;

[0040] Test group 4: 30 ml of exogenous total extracted glomalin-related soil protein extract, recorded as C.

[0041] After alfalfa was planted for 2 weeks, the glomalin-related soil protein extract was applied, each treatment was diluted to 50 ml with ultrapure water, and was evenly applied to the vanadium-titanium magnetite tailings along the alfalfa rhizosphere. Then the aforementioned glomalin-related soil protein extract was applied every two weeks, and the alfalfa was harvested after 50 days of planting.

[0042] (6) Test results: As can be seen from Table 2 below, the exogenous application of total extracted glomalin-related soil protein extract can significantly reduce the availability of heavy metal Cu in vanadium-titanium magnetite tailings, and increase the content of available nitrogen, available phosphorus and other nutrients, and promote the growth and development of alfalfa.

[0043] Table 2. Effect of different treatments on biomass of alfalfa, physicochemical properties of vanadium-titanium magnetite tailings and passivation of heavy metals

[0044]

[0045] As can be seen from Table 2 below, the exogenous application of total extracted glomalin-related soil protein extract can significantly reduce the availability of heavy metal Cu in vanadium-titanium magnetite tailings, and the content of available nitrogen, available phosphorus and other nutrients is significantly increased, and the increase is much higher than the content of available nitrogen and available phosphorus contained in the exogenous glomalin-related soil protein, indicating that in addition to the nitrogen and phosphorus directly brought into the tailings by the exogenous glomalin-related soil protein, other forms of nitrogen and phosphorus are also converted into available state that is more beneficial to plant absorption, thereby having a certain promoting effect on the growth and development of alfalfa.

[0046] Example 2:

[0047] (1) Artificial simulation of vanadium-titanium magnetite tailings contaminated with different concentrations of cadmium: 5 mg / kg of Cd was added to the vanadium-titanium magnetite tailings and balanced for one month, recorded as Cd-5;

[0048] (2) Preparation of GRSP extract (The glomalin-related soil protein used is obtained from a farmland 1.26 km southwest of a vanadium-titanium magnetite tailings pond in the downwind direction, and is separated according to the method of Wright and Upadhyaya (1998).):

[0049] a) Take the soil between 0-20 cm depth in the farmland near the vanadium-titanium magnetite tailings, mix evenly, and dry in a cool and ventilated place for use;

[0050] b) 1.00 g of air-dried soil was weighed into a 50 ml centrifuge tube, 8 ml of 50 mmol / L, pH 8.0 sodium citrate solution was added to the centrifuge tube, and the mixture was shaken well, then extracted at 121℃, 0.1 MPa for 60 min, cooled to room temperature, and centrifuged at 6000 r / min for 5 min, and the brown-red supernatant was taken; 8 ml of the same sodium citrate solution was added to the centrifuge tube, and the extraction-cooling-centrifugation-liquid taking operation was repeated until the brown-red color of the supernatant disappeared (7 times), and the supernatant obtained each time was mixed to obtain the GRSP extract, which was stored at 4℃;

[0051] c) After obtaining the spherulin-related soil protein extract, 0.1 mol / L hydrochloric acid solution was added until the pH was reduced to 2-2.5, ice-bath for 60 min, 6000 r / min centrifugation for 4 min, remove the supernatant, add 0.1 mol / L NaOH solution to the precipitate until the precipitate is completely dissolved and the pH is adjusted to 7-7.5.

[0052] d) The concentration of the obtained spherulin-related soil protein extract was determined, and the spherulin-related soil protein content was 0.026 mg•ml -1 .

[0053] (3) Test site:

[0054] The test was carried out in the greenhouse of Huazhong University of Science and Technology.

[0055] Select uniform and plump alfalfa seeds, surface sterilize with 10% H2O2 for 10 min, rinse with deionized water, and germinate in a biochemical incubator at 25℃ until the seeds germinate. The vanadium-titanium magnet tailings are sterilized by steam (121℃, 0.14Mpa, 2h) and then placed in experimental pots. Each pot contains 1 kg of vanadium-titanium magnet tailings and 100 seeds of alfalfa.

[0056] (4) Test statistical index:

[0057] The modified vanadium-titanium magnet tailings are sieved through a 20 mesh sieve, and then extracted with diethylenetriamine pentaacetic acid (C 14 H 23 N3O 10 , DTPA) to extract the available heavy metal Cd in the vanadium-titanium magnet tailings. The available nitrogen content in the vanadium-titanium magnet tailings is measured by alkali hydrolysis diffusion method, and the available phosphorus content in the vanadium-titanium magnet tailings is measured by sodium bicarbonate extraction method.

[0058] (5) Test group design:

[0059] The test group is divided into 4 groups, each with 3 parallel tests, and the specific test group design is as follows:

[0060] Test group 1: zero strength of exogenous total extracted glomalin-related soil protein extract as a control, recorded as CK;

[0061] Test group 2: 10 ml of exogenous total extracted glomalin-related soil protein extract, recorded as A;

[0062] Test group 3: 20 ml of exogenous total extracted glomalin-related soil protein extract, recorded as B;

[0063] Test group 4: 30 ml of exogenous total extracted glomalin-related soil protein extract, recorded as C.

[0064] The glomalin-related soil protein extract after alfalfa planting for 2 weeks is diluted to 50 ml with ultrapure water, and is uniformly applied to the vanadium-titanium magnetite tailings along the rhizosphere of alfalfa. Then the aforementioned glomalin-related soil protein extract is applied every two weeks, and the alfalfa is harvested after 50 days of planting.

[0065] (6) Test results: as shown in Table 3, the exogenous application of total extracted glomalin-related soil protein extract can significantly reduce the availability of heavy metals Cd in magnetite tailings, and the biomass of alfalfa is significantly increased.

[0066] Table 3 Physicochemical properties of vanadium-titanium magnetite tailings under different treatments

[0067]

[0068] Through comparison, the exogenous application of glomalin-related soil protein can reduce the availability of heavy metals Cu and Cd in vanadium-titanium magnetite tailings, increase the content of available nitrogen, available phosphorus and other nutrients in vanadium-titanium magnetite tailings, promote the growth and development of alfalfa, and significantly improve the effect of tailings improvement.

[0069] After the glomalin-related soil protein is applied to the vanadium-titanium magnetite tailings, the content of available nitrogen and available phosphorus in the vanadium-titanium magnetite tailings is increased, thereby promoting the growth of alfalfa and increasing the biomass. The application of GRSP to the vanadium-titanium magnetite tailings improves the physicochemical properties of the vanadium-titanium magnetite tailings and passivates the activity of heavy metals in the vanadium-titanium magnetite tailings.

Claims

1. A method for improving tailings using globulin-associated soil proteins, characterized in that, Exogenous application of globulin-related soil proteins to vanadium-titanium magnetite tailings planted with alfalfa; One hundred alfalfa plants were planted per kilogram of vanadium-titanium magnetite tailings. Two weeks after the alfalfa was planted on the vanadium-titanium magnetite tailings, globulin-related soil protein was exogenously applied to the vanadium-titanium magnetite tailings. Apply globulin-associated soil protein every 2 weeks; Gastromycin-associated soil proteins were applied in the form of glomerulone-associated soil protein extract; Soil samples used for extracting globulin-related soil proteins were taken from farmland located 1.26 km southwest of the vanadium-titanium magnetite tailings dam. Sodium citrate solution was added to the soil that had passed through a 20-mesh sieve, and the mixture was extracted at 121℃ and 0.1 MPa for 60 min. After cooling to room temperature, the mixture was centrifuged at 6000 r / min for 5 min, and the brownish-red supernatant was collected. Sodium citrate solution was added to the centrifuge tube again, and the extraction-cooling-centrifugation-collection process was repeated. The above operations were repeated until the brownish-red color of the supernatant disappeared. The obtained supernatants were mixed and stored at 4℃ for later use.

2. The method for improving tailings using globulin-related soil proteins according to claim 1, characterized in that, The ratio of soil to sodium citrate solution was 1g:8ml. The mixture was placed in a 50ml centrifuge tube. The concentration of the sodium citrate solution was 50mmol / L and the pH was 8.

3. The method for improving tailings using globulin-related soil proteins according to claim 1, characterized in that, After obtaining the globulin-associated soil protein solution, add 0.1 mol / L hydrochloric acid solution until the pH drops to 2-2.5, incubate on ice for 60 min, centrifuge at 6000 r / min for 4 min, remove the supernatant, add 0.1 mol / L NaOH solution until the precipitate is completely dissolved and adjust the pH to 7-7.

5.

4. The method for improving tailings using globulin-related soil proteins according to claim 3, characterized in that, The globulin-related soil protein extract was diluted with ultrapure water to 50 ml and then evenly applied to the vanadium-titanium magnetite tailings along the rhizosphere of alfalfa.

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