CN115500238B - Method for improving phosphogypsum storage yard soil by using waste straw - Google Patents

Abstract

The invention relates to a method for improving phosphogypsum storage yard soil by utilizing waste straws, which specifically comprises the following steps: s1: mixing phosphogypsum powder and alkaline soil according to a certain mass ratio to obtain pretreated phosphogypsum; s2: mixing the pretreated phosphogypsum with straw powder, and spraying a composite bacterial liquid to obtain a primary soil-like matrix; s3: introducing pioneer plants into the primary soil-like matrix to obtain a medium-grade soil-like matrix; s4: and introducing common plants into the medium soil-like matrix to obtain the high soil-like matrix. The invention has the beneficial effects that phosphogypsum storage yard can be subjected to soil formation, and meanwhile, the agricultural waste straw is efficiently utilized, so that the problem of piling up a large amount of phosphogypsum and the agricultural waste straw is solved, and the invention has great practical significance for environmental ecological protection and resource recycling integration and has the advantages of simple process, high treatment efficiency, green ecology and low cost.

Description

A method of using waste straw to improve the soil of phosphogypsum stockyards

Technical field

The present invention relates to the technical field of resource integrated utilization and ecological restoration, and specifically relates to a method for utilizing waste straw to improve the soil of a phosphogypsum stockpile.

Background technique

Phosphogypsum is a by-product obtained by decomposing phosphate rock with sulfuric acid during the production of wet phosphoric acid. It also contains harmful impurities such as phosphorus and fluorine. A large amount of phosphogypsum in my country is still mainly stored in stockpiles. The stockpiles of these phosphogypsum not only occupy a large amount of land, but their long-term stockpiling will cause the soluble phosphorus and fluorine contained in the phosphogypsum to enter the soil, surface water, and groundwater. Will cause serious environmental problems. At the same time, phosphogypsum is different from ordinary soil and conventional metal tailings in that it is highly discrete. The vertical permeability coefficient is greater than the horizontal permeability coefficient, causing caves and ditches to easily appear in the stockyard, which in turn leads to safety problems. In view of the environmental problems caused by the release of soluble phosphorus and soluble fluorine in phosphogypsum stockyards, in the context of increasingly strict environmental protection supervision and the transformation of the energy structure, the harmless disposal, soil improvement and ecological utilization of phosphogypsum are necessary. The healthy development of the phosphorus chemical industry chain is crucial.

Current research reports on the harmless treatment of phosphogypsum still mainly focus on the use and improvement of traditional methods for phosphogypsum treatment. Traditional methods have shortcomings such as single benefit, complex process, high energy consumption and secondary pollution. At present, there is no research on using phosphogypsum and agricultural straw combined with efficient biomass-degrading bacteria to achieve soilification of phosphogypsum.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for improving the soil of a phosphogypsum stockpile using waste straw, aiming to solve the problems in the existing technology.

The technical solutions of the present invention to solve the above technical problems are as follows:

A method of using waste straw to improve the soil of a phosphogypsum stockpile, specifically including the following steps:

S1: Mix phosphogypsum powder and alkaline soil according to a certain mass ratio to obtain pretreated phosphogypsum;

S2: Mix the above pretreated phosphogypsum and straw powder, and spray the compound bacterial solution to obtain a primary soil-like matrix;

S3: Introduce pioneer plants into the above-mentioned primary soil-like matrix to obtain an intermediate soil-like matrix;

S4: Introduce ordinary plants into the above-mentioned intermediate soil-like matrix to obtain an advanced soil-like matrix.

The beneficial effects of the present invention are: the present invention can soilize the phosphogypsum storage yard, and at the same time efficiently utilize agricultural waste straw, solve the problem of storing a large amount of phosphogypsum and agricultural waste straw, and comprehensively improve environmental and ecological protection and resource recycling. Chemicalization has great practical significance and has the advantages of simple process, high processing efficiency, green ecology and low cost.

On the basis of the above technical solution, the present invention can also make the following improvements.

Further, the step S1 also includes S0, the preparation of the composite bacterial solution, which specifically includes the following steps:

S01: Enrich and culture the isolated and purified strains in liquid culture media to obtain enriched culture solutions of different cellulose-degrading bacteria;

S02: The above-mentioned different enriched culture liquids are domesticated and cultured for generations to obtain domesticated culture liquids of different cellulose-degrading bacteria, and the above-mentioned different domesticated culture liquids are mixed according to a certain volume ratio to obtain a composite bacterial liquid.

The beneficial effect of adopting the above-mentioned further scheme is that the method is simple in process and can quickly obtain the compound bacterial liquid.

Further, the S01 specifically includes the following steps:

S011: Collect saprophytic plants and surrounding soil samples, put them into a container with sterile water at a mass ratio of (1-2):1, mix and settle, and obtain the supernatant;

S012: Put the above supernatant and enriched culture medium into a container according to the volume ratio (0.1-0.4):1, place the container in a constant temperature shaker at 25-35°C, and shake and culture at a speed of 160-200 rpm. , to obtain enriched bacterial liquid;

S013: Mix the enriched bacterial liquid and cellulolytic medium evenly according to the volume ratio of 2: (5-10), then culture it in a constant temperature shaker at 26-32°C at a speed of 160-200 rpm for 3-7 days. , obtain the cellulose composite bacteria liquid;

S014: Inoculate the cellulose complex bacterial solution into the cellulolytic medium, and incubate it upside down at 26-32°C for 3-5 days to obtain colonies of cellulose-degrading bacteria, and select single colonies with different shapes to draw lines on the plate. Purify and culture at 26-32°C for 3-5 days through isolation and culture to obtain the purified cellulolytic bacteria strain;

S015: Inoculate the purified cellulose-degrading bacterial strain into the cellulolytic medium, culture it upside down at 28-30°C for 3-5 days, and screen out the cellulose-degrading strain with a transparent circle;

S016: Inoculate the selected cellulose-degrading strain into the liquid enzyme-producing medium, place it in a constant-temperature shaker at 26-32°C, and culture it with shaking at a speed of 160-200 rpm for 5-7 days. The cellulase activity is high and low and efficient cellulose-degrading bacteria are obtained;

S017: Isolate and screen out strains of Cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium and Bacillus amyloliquefaciens, and place the above selected strains in the expanded culture medium at a constant temperature of 26-32°C The shaker was incubated at a rotation speed of 180-220 rpm for 5-7 days to obtain different enriched culture fluids after expanded culture.

The beneficial effects of adopting the above-mentioned further scheme are that the method is simple in process, can quickly obtain different enriched culture fluids, and is convenient and fast.

Further, the S02 specifically includes the following steps:

S021: Inoculate the enriched culture solution of different cellulose-degrading bacteria into the acclimation medium containing straw powder and phosphogypsum, and subculture it at 26-32°C for 4-7 times until the cellulose-degrading bacteria in each bacterial solution The total concentration is 10 ⁷ -10 ⁹ /mL, and different cellulose-degrading bacteria liquids are obtained;

S022: Expand culture different cellulose-degrading bacteria liquids separately, and mix them according to a certain volume ratio to make a composite bacterial liquid.

The beneficial effect of adopting the above-mentioned further scheme is that the method has a simple process and can use enriched culture liquid to obtain different cellulose-degrading bacterial liquids, and then use different cellulose-degrading bacterial liquids to expand the culture and obtain a composite bacterial liquid.

Further, in the S1, phosphogypsum and alkaline soil are mixed according to a mass ratio of 1: (2-4).

The beneficial effect of adopting the above further scheme is that the ratio is suitable to better utilize phosphogypsum and alkaline soil, treat waste with waste, save energy and protect the environment.

Further, the S2 specifically includes the following steps:

S21: Put the pretreated phosphogypsum and waste straw powder into a mixer according to the mass ratio of 1: (1-3), and mix at a speed of 40-60 rpm for 2-10 hours to obtain organophosphogypsum;

S22: Spray the compound bacterial solution into the organophosphogypsum intermittently at a spray speed of 7-15L/(hm ² ), spray for 1 hour every 1-2 hours, and after 15-60 days of growth and colonization, obtain Primary soil-like matrix.

The beneficial effect of adopting the above-mentioned further scheme is that the method is simple in process and uses the bacteria in the compound bacterial solution to decompose the components in the primary soil to obtain a primary soil-like matrix.

Further, the S3 specifically includes the following steps:

Pioneer plants are planted in the primary soil-like matrix in S2, and after 1-5 rounds of colonization and growth, an intermediate soil-like matrix is obtained.

The beneficial effect of adopting the above-mentioned further scheme is that the selection is reasonable. The above-mentioned pioneer plants have the characteristics of tenacious vitality, fast growth rate, strong environmental resistance, and developed root systems. They can comprehensively improve the ecological functions of phosphogypsum through their root physiological activities.

Further, in S3, the pioneer plant includes one or more of fern and ryegrass.

The beneficial effects of adopting the above further scheme are reasonable selection, common varieties and convenient material collection.

Further, the S4 specifically includes the following steps: planting ordinary plants in the intermediate soil-like matrix in the S3, and obtaining a high-grade soil-like matrix after 1-5 rounds of planting and growth.

The beneficial effects of adopting the above-mentioned further scheme are simple process, reasonable design, and further improving the nutrition of the soil-like matrix.

Further, in the S4, the common plants include one or more of Alpinia parvum, Poa annua, alfalfa and Lotus japonicus.

The beneficial effect of adopting the above further solution is that the above-mentioned common plants can promote plant growth and exert physiological functions, promote the formation of aggregates and increase mineral nutrients.

Description of the drawings

Figure 1 is a process flow diagram of the present invention.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and The simplified description is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined by "first," "second," etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Example 1

As shown in Figure 1, this embodiment provides a method for using waste straw to improve the soil of a phosphogypsum stockpile, which specifically includes the following steps:

S1: Mix phosphogypsum powder and alkaline soil according to a certain mass ratio to obtain pretreated phosphogypsum;

S2: Mix the above pretreated phosphogypsum and straw powder, and spray the compound bacterial solution to obtain a primary soil-like matrix;

S3: Introduce pioneer plants into the above-mentioned primary soil-like matrix to obtain an intermediate soil-like matrix;

S4: Introduce ordinary plants into the above-mentioned intermediate soil-like matrix to obtain an advanced soil-like matrix.

This embodiment can soilize the phosphogypsum storage yard, and at the same time efficiently utilize agricultural waste straw, solving the problem of storing a large amount of phosphogypsum and agricultural waste straw, and has great practicality for environmental and ecological protection and comprehensive resource recycling. It has the advantages of simple process, high processing efficiency, green ecology and low cost.

Example 2

On the basis of Example 1, in this example, S1 is preceded by S0, and the preparation of the composite bacterial solution specifically includes the following steps:

S01: Enrich and culture the isolated and purified strains in liquid culture media to obtain enriched culture solutions of different cellulose-degrading bacteria;

S02: The above-mentioned different enriched culture liquids are domesticated and cultured for generations to obtain domesticated culture liquids of different cellulose-degrading bacteria, and the above-mentioned different domesticated culture liquids are mixed according to a certain volume ratio to obtain a composite bacterial liquid.

This method has a simple process and can quickly obtain a compound bacterial solution.

Example 3

Based on Embodiment 2, in this embodiment, the S01 specifically includes the following steps:

S011: Collect saprophytic plants and surrounding soil samples, put them into a container with sterile water at a mass ratio of (1-2):1, mix and settle, and obtain the supernatant;

S012: Put the above supernatant and enriched culture medium into a container according to the volume ratio (0.1-0.4):1, place the container in a constant temperature shaker at 25-35°C, and shake and culture at a speed of 160-200 rpm. , to obtain enriched bacterial liquid;

S013: Mix the enriched bacterial liquid and cellulolytic medium evenly according to the volume ratio of 2: (5-10), then culture it in a constant temperature shaker at 26-32°C at a speed of 160-200 rpm for 3-7 days. , obtain the cellulose composite bacteria liquid;

S014: Inoculate the cellulose complex bacterial solution into the cellulolytic medium, and incubate it upside down at 26-32°C for 3-5 days to obtain colonies of cellulose-degrading bacteria, and select single colonies with different shapes to draw lines on the plate. Purify and culture at 26-32°C for 3-5 days through isolation and culture to obtain the purified cellulolytic bacteria strain;

S015: Inoculate the purified cellulose-degrading bacterial strain into the cellulolytic medium, culture it upside down at 28-30°C for 3-5 days, and screen out the cellulose-degrading strain with a transparent circle;

S016: Inoculate the selected cellulose-degrading strain into the liquid enzyme-producing medium, place it in a constant-temperature shaker at 26-32°C, and culture it with shaking at a speed of 160-200 rpm for 5-7 days. The cellulase activity is high and low and efficient cellulose-degrading bacteria are obtained;

S017: Isolate and screen out strains of Cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium and Bacillus amyloliquefaciens, and place the above selected strains in the expanded culture medium at a constant temperature of 26-32°C The shaker was incubated at a rotation speed of 180-220 rpm for 5-7 days to obtain different enriched culture fluids after expanded culture.

This method has a simple process, can quickly obtain different enriched culture fluids, and is convenient and fast.

Preferably, in this embodiment, the highly efficient cellulose-degrading bacteria are subjected to 16S rDNA identification and NCBI comparison (molecular identification). After comparison, it is determined that the strains isolated and screened are: Pseudomonas cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium amyloliquefaciens, Bacillus amyloliquefaciens.

Preferably, in this embodiment, the components of the enrichment medium are: 2g/LK ₂ HPO ₄ , 1.4g/L (NH ₄ ) ₂ SO ₄ , 0.3g/L MgSO ₄ ·7H ₂ O, 0.3g /L Ca Cl ₂ , 5mg/L FeSO ₄ ·7H ₂ O, 1.6 mg/L MnSO ₄ , 1.7mg/LZnSO ₄ and 2mg/L CoCl _2. The solvent is sterile water.

Preferably, in this embodiment, the components of the above-mentioned cellulolytic medium are: 10g/L sodium carboxymethylcellulose, 2g/LK ₂ HPO ₄ , 0.5g/L MgSO ₄ , 0.25g/L Congo red, 16g /L agar and 3g/L gelatin, the solvent is sterile water.

Preferably, in this embodiment, the components of the above-mentioned liquid enzyme-producing culture medium are: 5-10g/L sodium carboxymethylcellulose, 1-2g/L NH ₄ Cl, 0.5-1g/L MgSO ₄ ·7H ₂ O, 1-2g/L KH ₂ PO ₄ and 1-2g/L yeast extract powder, the solvent is sterile water.

Preferably, in this embodiment, the components of the above-mentioned expanded culture medium are: tryptone 10g/L, yeast extract 5g/L and sodium chloride 10g/L, and the solvent is sterile water.

Example 4

Based on any one of Embodiment 2 to Embodiment 3, in this embodiment, the S02 specifically includes the following steps:

S021: Inoculate the enriched culture solution of different cellulose-degrading bacteria into the acclimation medium containing straw powder and phosphogypsum, and subculture it at 26-32°C for 4-7 times until the cellulose-degrading bacteria in each bacterial solution The total concentration is 10 ⁷ -10 ⁹ /mL, and different cellulose-degrading bacteria liquids are obtained;

S022: Expand culture different cellulose-degrading bacteria liquids separately, and mix them according to a certain volume ratio to make a composite bacterial liquid.

This method has a simple process and can use enriched culture liquid to obtain different cellulose-degrading bacterial liquids, and then use different cellulose-degrading bacterial liquids to expand the culture and obtain a composite bacterial liquid.

Preferably, in this embodiment, the components of the above-mentioned acclimation liquid culture medium are: 1.0g/L KH ₂ PO ₄ , 0.3g/LMgSO ₄ , 0.1g/L NaCl, 2.5g/L NaNO ₃ , 0.1/L CaCl ₂ ·6H ₂ O, 0.01g/L FeCl ₃ , 20g/L straw powder and 10g/L phosphogypsum powder, the solvent is sterile water.

Preferably, in this embodiment, the above-mentioned strains of Cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium and Bacillus amyloliquefaciens in S022 are according to 1: (1-3): (2-4 ):(1-3):(1-3):(2-4) to prepare a compound bacterial solution.

Example 5

On the basis of the above embodiments, in this embodiment, in S1, phosphogypsum and alkaline soil are mixed according to a mass ratio of 1: (2-4).

The ratio is appropriate to better utilize phosphogypsum and alkaline soil, treat waste with waste, save energy and protect the environment.

Example 6

Based on the above embodiments, in this embodiment, the S2 specifically includes the following steps:

S21: Put the pretreated phosphogypsum and waste straw powder into a mixer according to the mass ratio of 1: (1-3), and mix at a speed of 40-60 rpm for 2-10 hours to obtain organophosphogypsum;

S22: Spray the compound bacterial solution into the organophosphogypsum intermittently at a spray speed of 7-15L/(hm ² ), spray for 1 hour every 1-2 hours, and after 15-60 days of growth and colonization, obtain Primary soil-like matrix.

This method has a simple process and uses bacteria in the compound bacterial solution to decompose the components in organophosphogypsum to obtain a primary soil-like matrix.

Example 7

Based on the above embodiments, in this embodiment, the S3 specifically includes the following steps:

Pioneer plants are planted in the primary soil-like matrix in S2, and after 1-5 rounds of colonization and growth, an intermediate soil-like matrix is obtained.

The choice of this plan is reasonable. The above-mentioned pioneer plants have the characteristics of tenacious vitality, fast growth rate, strong environmental resistance, and developed root systems. They can comprehensively improve the ecological functions of phosphogypsum through their root physiological activities.

Example 8

On the basis of Example 7, in this example, in S3, the pioneer plant includes one or more of ferns and ryegrass.

The program is reasonably selected, with common varieties and easy access to materials.

Example 9

Based on the above embodiments, in this embodiment, the S4 specifically includes the following steps:

Ordinary plants are planted in the intermediate soil-like matrix in S3, and after 1-5 rounds of planting and growth, a high-grade soil-like matrix is obtained.

This solution has simple technology and reasonable design, which can further improve the nutrition of soil-like substrate.

Example 10

On the basis of Embodiment 9, in this embodiment, in S4, common plants include one or more of Alpinia parvum, Poa annua, alfalfa, and Lotus japonicus.

The above-mentioned common plants can promote plant growth and physiological functions, promote the formation of aggregates and increase mineral nutrients.

The embodiments of the above-mentioned pioneer plants and common plants are as follows:

Example 11

A method of using waste straw to improve the soil of a phosphogypsum stockpile, including the following steps:

1) Collect saprophytic plants and surrounding soil samples, put them into a container with sterile water at a mass ratio of 1:1, mix and settle, and obtain the supernatant;

Put the supernatant and enriched culture medium into a container at a volume ratio of 0.2:1, place the container on a 30°C constant-temperature shaker and perform shaking culture at 160 rpm to obtain enriched bacterial liquid;

Mix the enriched bacterial liquid and cellulolytic culture medium at a volume ratio of 2:5, then place them in a constant temperature shaker at 28°C and culture them at a rotation speed of 180 rpm for 3 days to obtain a cellulose compound bacterial liquid;

Inoculate the composite bacterial solution obtained after culture into the cellulose-degrading medium, and incubate it upside down at 28°C for 3 days to obtain colonies of cellulose-degrading bacteria. Select single colonies with different shapes and separate them by drawing lines on a plate. Purify and culture at 30°C for 3 days to obtain the purified cellulolytic bacteria strain;

Inoculate the purified cellulose-degrading bacterial strain into the cellulolytic medium, culture it upside down at 30°C for 3 days, and screen out the cellulose-degrading strain with a transparent circle;

The selected cellulose-degrading strain was inoculated into a liquid enzyme-producing medium, placed in a constant-temperature shaker at 28°C and cultured at a rotation speed of 180 rpm for 5 days. After comparing the total cellulase activity in the culture medium, select this strain. The strain with the highest index was identified as an efficient cellulose-degrading bacterium;

The high-efficiency cellulose-degrading bacteria were identified by 16S rDNA, and the strains isolated and screened were determined to be: Pseudomonas cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium, and Bacillus amyloliquefaciens.

The high-efficiency cellulose-degrading bacteria are expanded and cultured in a constant-temperature shaker at 28°C and 180 rpm for 5 days to obtain the expanded cultured bacterial liquid.

2) Inoculate different cellulose-degrading bacteria liquids into an acclimation medium containing straw powder and phosphogypsum, and subculture it at 28°C for 4 times until the total concentration of cellulose-degrading bacteria in each bacterial liquid is 10 ⁷ /mL;

Expand the selected colonies of the domesticated Celeroides, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium, and Bacillus amyloliquefaciens, and follow 1:2:4:3:2: The volume ratio of 4 is used to prepare a compound bacterial liquid.

3) Mix phosphogypsum and alkaline soil evenly at a mass ratio of 1:3 to obtain pretreated phosphogypsum.

4) Put the pretreated phosphogypsum and waste straw powder into a mixer at a mass ratio of 1:3, and mix at a speed of 45 rpm for 6 hours to obtain organophosphogypsum;

Mix the selected and domesticated high-efficiency cellulose-degrading bacteria according to the volume ratio of 1:2:4:3:2:4 to prepare a composite bacterial solution and then spray it into the organophosphogypsum;

The spray speed of the compound bacterial solution is 7L/(hm ² ), and the spraying method is intermittent, spraying for 1 hour every 1 hour. After 60 days of growth and colonization, the microorganisms in the compound bacterial solution obtain a primary soil-like matrix.

5) Plant the pioneer plant Pteris fern in the primary soil-like matrix and provide its corresponding growth environment and nutrients. The obtained primary soil-like matrix was stabilized at room temperature for 5 days to allow the internal physical and chemical conditions to reach a certain balance. Plantings were carried out directly in primary soil-like substrates, and seed germination rates were also calculated. Divide into 5 groups. The amount of soil in each group is 10kg. The number of seeds sown in each group is 9, 11, 13, 14 and 15. The germination rate is calculated after 7 days. After two cycles of plant growth and colonization, an intermediate soil-like matrix is obtained.

6) In the intermediate soil-like matrix, plant Alpinia parviflora, Bluegrass, alfalfa, Lotus japonicus and other plants. Sow 10 seeds + 3 Lotus japonicus seeds, apply compound fertilizer once every three days, and calculate the seed germination rate after 7 days. After three cycles of plant growth and colonization, a high-grade soil-like matrix is obtained.

Table 1 shows the physical and chemical indicators of the improved soil in this example.

According to the data in Table 1, it can be seen that the nutrients in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are significantly improved, and the nutritional components of the soil in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are in order be promoted.

Example 12

A method of using waste straw to improve the soil of a phosphogypsum stockpile, including the following steps:

1) Collect saprophytic plants and surrounding soil samples, put them into a container with sterile water at a weight ratio of 2:1, mix and settle, and obtain the supernatant;

Put the supernatant and enriched culture medium into a container at a volume ratio of 0.4:1, place the container in a 30°C constant-temperature shaker and perform shaking culture at 200 rpm to obtain enriched bacterial liquid;

After the enriched bacterial liquid and cellulolytic medium are evenly mixed according to a volume ratio of 2:7, they are placed in a constant temperature shaker at 28°C and cultured at a rotation speed of 160 rpm for 5 days to obtain a cellulose compound bacterial liquid;

Inoculate the composite bacterial solution obtained after culture into the cellulolytic medium, and incubate it upside down at 30°C for 3 days to obtain colonies of cellulose-degrading bacteria. Select single colonies with different shapes and separate them by drawing lines on a plate. Purify and culture at 28°C for 4 days to obtain the purified cellulolytic bacteria strain;

Inoculate the purified cellulose-degrading bacterial strain into the cellulolytic medium, culture it upside down at 30°C for 3 days, and screen out the cellulose-degrading strain with a transparent circle;

The selected cellulose-degrading strains were inoculated into a liquid enzyme-producing culture medium, placed in a 30°C constant-temperature shaker at a rotation speed of 200 rpm, and cultured for 7 days. After comparing the total cellulase activity in the culture medium, select this strain. The strain with the highest index was identified as an efficient cellulose-degrading bacterium;

The high-efficiency cellulose-degrading bacteria were identified by 16S rDNA, and the strains isolated and screened were determined to be: Pseudomonas cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium, and Bacillus amyloliquefaciens;

The high-efficiency cellulose-degrading bacteria are expanded and cultured, placed in a 30°C constant-temperature shaker at a rotation speed of 200 rpm for 5 days, and the expanded cultured bacterial liquid is obtained.

2) Inoculate different cellulose-degrading bacteria liquids into the acclimation medium containing straw powder and phosphogypsum, and subculture it at 28°C for 6 times until the total concentration of cellulose-degrading bacteria in each bacterial liquid is 10 ⁷ /mL;

Expand the selected colonies of the domesticated Celeroides, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium, and Bacillus amyloliquefaciens at a volume ratio of 1:2:4:3:2 :4 Make compound bacterial liquid.

3) Fully mix phosphogypsum and alkaline soil at a mass ratio of 1:2 to obtain pretreated phosphogypsum.

4) Put the pretreated phosphogypsum and waste straw powder into a mixer at a mass ratio of 1:3, and mix at a speed of 45 rpm for 4 hours to obtain organophosphogypsum;

Mix the selected and domesticated high-efficiency cellulose-degrading bacteria in a volume ratio of 1:2:4:3:2:4 to prepare a composite bacterial solution and then spray it into the organophosphogypsum;

The spray speed of the compound bacterial solution is 15L/(h.m2), and the spray method is intermittent, spraying for 1 hour every 2 hours. After 30 days of growth and colonization of the microorganisms in the compound bacterial solution, a primary soil-like matrix is obtained.

5) Plant the pioneer plant ryegrass in the primary soil-like matrix and provide its corresponding growth environment and nutrients. The obtained primary soil-like matrix was stabilized at room temperature for 5 days to allow the internal physical and chemical conditions to reach a certain balance.

Plant directly in a primary soil-like substrate and the seed germination rate is also calculated. Divided into 5 groups, the amount of soil in each group is 7kg, 9kg, 10kg, 12kg, and 15kg. The number of ryegrass seeds sown in each group is 9, 11, 13, 14, and 15. After 7 days, the germination rate is calculated after three cycles of plant growth. After time of colonization, an intermediate soil-like matrix is obtained.

6) In the intermediate soil-like matrix, plant Alpinia parviflora, Bluegrass, alfalfa, Lotus japonicus and other plants. Sow 13 seeds + 3 Lotus japonicus seeds, apply compound fertilizer once every three days, and calculate the seed germination rate after 7 days. After three cycles of plant growth and colonization, a high-grade soil-like matrix is obtained.

Table 2 shows the physical and chemical indicators of the improved soil in this example.

project Phosphogypsum group Primary soil-like matrix Intermediate soil-like matrix Advanced soil-like matrix pH value 1.4 4.47 5.12 7.57 Total soil porosity (%) / 34% 44% 57% nitrogen(%) / 0.07% 0.22% 0.30% Total phosphorus (g/kg) / 0.47 0.59 0.79 Total potassium (g/kg) / 11 14 twenty one humic acid / 0.64% 0.17% 2.01%

According to the data in Table 2, it can be seen that the nutrients in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are significantly improved, and the nutritional components of the soil in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are in order be promoted.

Example 13

A method of using waste straw to improve the soil of a phosphogypsum stockpile, including the following steps:

1) Collect saprophytic plants and surrounding soil samples, put them into a container with sterile water at a weight ratio of 2:1, mix and settle, and obtain the supernatant;

Put the supernatant and enriched culture medium into a container at a volume ratio of 0.3:1, place the container on a 30°C constant-temperature shaker and perform shaking culture at 200 rpm to obtain enriched bacterial liquid;

After the enriched bacterial liquid and cellulolytic medium are evenly mixed according to a volume ratio of 2:10, they are placed in a constant temperature shaker at 26°C and cultured at a rotation speed of 200 rpm for 5 days to obtain a cellulose compound bacterial liquid;

Inoculate the composite bacterial solution obtained after culture into the cellulolytic medium and incubate it upside down at 32°C for 3 days to obtain colonies of cellulose-degrading bacteria. Select single colonies with different shapes and separate them by drawing lines on a plate. Purify and culture at 32°C for 3 days to obtain the purified cellulolytic bacteria strain;

Inoculate the purified cellulose-degrading bacterial strain into the cellulolytic medium, culture it upside down at 30°C for 3 days, and screen out the cellulose-degrading strain with a transparent circle;

The selected cellulose-degrading strain was inoculated into a liquid enzyme-producing culture medium, placed in a 30°C constant-temperature shaker at a rotation speed of 180 rpm, and cultured for 7 days. After comparing the total cellulase activity in the culture medium, select this strain. The strain with the highest index was identified as an efficient cellulose-degrading bacterium;

The high-efficiency cellulose-degrading bacteria were identified by 16S rDNA, and the strains isolated and screened were determined to be: Pseudomonas cereus, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium, and Bacillus amyloliquefaciens;

The high-efficiency cellulose-degrading bacteria are expanded and cultured, placed in a 30°C constant-temperature shaker at a rotation speed of 180 rpm for 5 days, and the expanded cultured bacterial liquid is obtained.

2) Inoculate different cellulose-degrading bacteria liquids into the acclimation medium containing straw powder and phosphogypsum, and subculture it at 28°C for 6 times until the total concentration of cellulose-degrading bacteria in each bacterial liquid is 10 ⁷ /mL;

Expand the selected colonies of domesticated Celeroides, Streptomyces, Bacillus subtilis, Trichoderma reesei, Chaetomium and Bacillus amyloliquefaciens at a volume ratio of 1:3:4:3:1 :4 Make compound bacterial liquid.

3) Fully mix phosphogypsum and alkaline soil at a mass ratio of 1:3 to obtain pretreated phosphogypsum.

4) Put the pretreated phosphogypsum and waste straw powder into a mixer at a mass ratio of 1:3, and mix at a speed of 45 rpm for 8 hours to obtain organophosphogypsum;

Mix the selected and domesticated high-efficiency cellulose-degrading bacteria in a volume ratio of 1:3:3:3:2:4 to prepare a composite bacterial solution and then spray it into the pretreated phosphogypsum;

The spray speed of the compound bacterial solution is 10L/(h.m2), and the spray method is intermittent, spraying for 1 hour every 2 hours. After 45 days of growth and colonization, the microorganisms in the compound bacterial solution obtain a primary soil-like matrix.

5) Plant the pioneer plant ryegrass in the primary soil-like matrix and provide its corresponding growth environment and nutrients. The obtained primary soil-like matrix was stabilized at room temperature for 5 days to allow the internal physical and chemical conditions to reach a certain balance.

Plant directly in a primary soil-like substrate and the seed germination rate is also calculated. Divided into 5 groups, the amount of soil in each group is 7kg, 9kg, 10kg, 12kg, and 15kg. The number of ryegrass seeds sown in each group is 9, 11, 13, 14, and 15. After 7 days, the germination rate is calculated after three cycles of plant growth. After time of colonization, an intermediate soil-like matrix is obtained.

6) In the intermediate soil-like matrix, plant Alpinia parviflora, Bluegrass, alfalfa, Lotus japonicus and other plants. Sow 13 seeds + 3 Lotus japonicus seeds, apply compound fertilizer once every three days, and calculate the seed germination rate after 7 days. After three cycles of plant growth and colonization, a high-grade soil-like matrix is obtained.

Table 3 shows the physical and chemical indicators of the improved soil in this example.

project Phosphogypsum group Primary soil-like matrix Intermediate soil-like matrix Advanced soil-like matrix pH value 1.4 4.53 5.46 7.88 Total soil porosity (%) / 36% 43% 56% nitrogen(%) / 0.09% 0.23% 0.32% Total phosphorus (g/kg) / 0.43 0.55 0.77 Total potassium (g/kg) / 13 16 twenty four humic acid / 0.64% 0.21% 2.07%

According to the data in Table 3, it can be seen that the nutrients in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are significantly improved, and the nutritional components of the soil in the primary soil-like matrix, intermediate soil-like matrix and advanced soil-like matrix are in order be promoted.

The invention combines agricultural waste straw to convert the phosphogypsum stockpile into a soil-like matrix, which can not only solve the problem of storing phosphogypsum and agricultural waste straw, but also improve soil problems.

The beneficial effects of the present invention are:

1. Phosphogypsum comes from the phosphogypsum storage yard. The method of the present invention can solve the problem of storing a large amount of phosphogypsum. Moreover, the present invention makes full use of waste biomass and can also solve the problem of storing a large amount of agricultural waste straw;

2. Combining phosphogypsum with waste biomass for soil improvement not only solves the pollution problem, but also achieves better integration of waste polluted resources. It has high application value and is in line with the national concept of protecting the environment and ecology;

3. The present invention has the characteristics of simple process, high processing efficiency, green ecology and low cost.

The agricultural waste straw used in the present invention, after being decomposed by cellulolytic bacteria, can not only provide available nutrients for microorganisms, etc., but due to its structural characteristics, it is also easier for microorganisms to colonize in the straw after growth. The phosphogypsum used in the present invention can not only improve the soil environment, but also increase the absorbable amount of phosphorus during the interaction between microorganisms and microorganisms, enhance soil fertility, and provide nutrients needed by plants. Phosphogypsum It can also improve the physical and chemical environment of the soil, thereby improving the soil with phosphogypsum.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

In addition, it should be understood that although this specification is described in terms of implementations, not each implementation only contains an independent technical solution. This description of the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole. , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

1. The method for improving the phosphogypsum storage yard soil by utilizing the waste straws is characterized by comprising the following steps of:

s1: mixing phosphogypsum powder and alkaline soil according to a certain mass ratio to obtain pretreated phosphogypsum, wherein the preparation method comprises the following steps:

s01: the different separated and purified strains are respectively enriched and cultured in a liquid culture medium to obtain enriched culture solutions of different cellulose degrading bacteria, and the enriched culture solutions are specifically as follows:

s011: collecting saprophyte and surrounding soil samples, filling the saprophyte and the surrounding soil samples into a container according to a mass ratio (1-2) of 1 with sterile water, mixing and precipitating to obtain supernatant;

s012: filling the supernatant and the enrichment medium into a container according to the volume ratio (0.1-0.4): 1, and placing the container into a constant temperature shaking table at 25-35 ℃ for shaking culture at the rotating speed of 160-200 rpm to obtain an enrichment bacterial liquid;

s013: uniformly mixing the enriched bacterial liquid and a cellulolytic culture medium according to the volume ratio of (5-10), and culturing for 3-7 days at a constant temperature shaking table of 26-32 ℃ and a rotating speed of 160-200 rpm to obtain a cellulose composite bacterial liquid;

s014: inoculating the cellulose composite bacterial liquid into a cellulolytic culture medium, inversely culturing for 3-5 days at 26-32 ℃ to obtain bacterial colonies of cellulose degrading bacteria, selecting single bacterial colonies with different forms, purifying and culturing for 3-5 days at 26-32 ℃ by using a plate drawing line separation culture mode to obtain purified cellulolytic bacterial strains;

s015: inoculating the purified cellulose degrading strain into a cellulose degrading culture medium, and reversely culturing for 3-5 days at 28-30 ℃ to screen the cellulose degrading strain with transparent rings;

s016: inoculating the screened cellulose degradation strain into a liquid enzyme production culture medium, placing the liquid enzyme production culture medium in a constant temperature shaking table at 26-32 ℃ for shaking culture at a rotating speed of 160-200 rpm for 5-7 days, and comparing the total cellulase activity in the culture solution to obtain high-efficiency cellulose degradation bacteria;

s017: separating and screening strains of cermets, streptomyces, bacillus subtilis, trichoderma reesei, chaetomium and bacillus amyloliquefaciens, and placing the strains screened by the expansion culture medium into a constant temperature shaking table at 26-32 ℃ for culturing for 5-7 days at a rotating speed of 180-220 rpm to obtain different enrichment culture solutions after expansion culture;

s02: respectively carrying out generation domestication culture on the different enrichment culture solutions to obtain domestication culture solutions of different cellulose degrading bacteria, and mixing the different domestication culture solutions according to a certain volume ratio to obtain a composite bacterial solution

S2: mixing the pretreated phosphogypsum with straw powder, and spraying a composite bacterial liquid to obtain a primary soil-like matrix;

s3: introducing pioneer plants into the primary soil-like matrix to obtain a medium-grade soil-like matrix;

s4: and introducing common plants into the medium soil-like matrix to obtain the high soil-like matrix.

2. The method for improving phosphogypsum yard soil by using waste straw as claimed in claim 1, wherein the step S02 specifically comprises the following steps:

s021: inoculating the enriched culture solution of different cellulose degrading bacteria into domestication culture medium containing straw powder and phosphogypsum, and subculturing at 26-32deg.C for 4-7 times until fiber in each bacterial solutionThe total concentration of the vitamin degrading bacteria is 10 ⁷ -10 ⁹ Obtaining different cellulose degrading bacteria liquid by the method per mL;

s022: and (3) respectively carrying out expansion culture on different cellulose degrading bacterial solutions, and mixing the bacterial solutions according to a certain volume ratio to prepare the composite bacterial solution.

3. The method for improving phosphogypsum yard soil by using waste straws according to any one of claims 1-2, which is characterized in that: in the step S1, phosphogypsum and alkaline soil are mixed according to the mass ratio of 1 (2-4).

4. The method for improving the phosphogypsum yard soil by utilizing waste straws according to any one of claims 1-2, wherein the step S2 specifically comprises the following steps:

s21: the preparation method comprises the following steps of (1) pre-treating phosphogypsum and waste straw powder according to a mass ratio of 1: (1-3) placing the mixture into a stirrer, and mixing the mixture for 2-10 hours at a rotating speed of 40-60 revolutions per minute to obtain the organic phosphogypsum;

s22: the compound bacterial liquid is treated by 7-15L/(h.m) ² ) The spraying speed of the water-based composite material is intermittently sprayed in the organic phosphogypsum for 1h at intervals of 1-2h, and the primary soil-like matrix is obtained after 15-60 days of growth and field planting.

5. The method for improving the phosphogypsum yard soil by utilizing waste straws according to any one of claims 1-2, wherein the step S3 specifically comprises the following steps:

and (2) planting pioneer plants in the primary soil-like matrix in the step (S2), and obtaining the intermediate soil-like matrix after 1-5 rounds of field planting growth.

6. The method for improving phosphogypsum yard soil by using waste straws as set forth in claim 5, which is characterized in that: in the step S3, the pioneer plant comprises one or more of pteris multifida and ryegrass.

7. The method for improving the phosphogypsum yard soil by utilizing waste straws according to any one of claims 1-2, wherein the step S4 specifically comprises the following steps: and (3) planting the common plants in the medium-class soil matrix in the step (S3), and obtaining the high-class soil matrix after 1-5 rounds of field planting growth.

8. The method for improving phosphogypsum yard soil by using waste straw as set forth in claim 7, which is characterized in that: in the step S4, the common plants comprise one or more of the group consisting of fescue, bluegrass, alfalfa and centella asiatica.