A soil remediation agent containing construction waste resource processing products and a preparation method and application thereof

Abstract

The application relates to the technical field of soil remediation, and specifically discloses a soil remediation agent containing construction waste resource processing products and a preparation method and application thereof. The soil remediation agent disclosed by the application comprises 1.5-2.5 parts of construction waste resource processing products, 0.1-0.3 parts of mineral substances and 0.6-1.0 parts of modified kaolin. The preparation method of the construction waste resource processing products is as follows: the construction waste is purified through magnetic separation and air separation, crushed, pyrolyzed, soaked in an activation liquid, filtered, dried and ground to obtain the construction waste resource processing products; the preparation method of the modified kaolin is as follows: kaolin, corn starch and water are uniformly mixed, compound bacteria are added and uniformly mixed, and then fermentation, drying and grinding are carried out to obtain the modified kaolin; the compound bacteria are composed of bacillus subtilis and bacillus laterosporus. The soil remediation agent provided by the application can effectively reduce the content of effective cadmium in soil, thereby improving the production safety of plant planting and effectively improving the yield of plants.

Description

Technical Field

[0001] The present application relates to the technical field of soil remediation, and in particular to a soil remediation agent comprising construction waste resource treatment products, and a preparation method and application thereof. Background Art

[0002] Currently, soil pollution is a serious problem worldwide. With the acceleration of urbanization, chemical pollution and heavy metals such as cadmium, lead, mercury, and arsenic have become major soil pollutants. Excessive fertilizer application causes soil acidification, which further activates heavy metals in the soil, creating a vicious cycle. Therefore, soil remediation has attracted industry attention. At the same time, the vast amount of waste generated by the construction industry is not effectively utilized, instead occupying valuable land resources and causing secondary environmental pollution.

[0003] Existing soil remediation and construction material reuse technologies operate independently, lacking an effective integration strategy. Traditional soil remediation agents are expensive and complex to prepare, while construction waste is often randomly dumped or landfilled, wasting resources and exacerbating environmental pollution.

[0004] Faced with the dual pressures of soil heavy metal pollution and construction waste disposal, how to develop low-cost, easy-to-operate new remediation agents and their preparation methods has become an urgent problem to be solved. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a soil remediation agent containing construction waste resource treatment products and a preparation method and application thereof.

[0006] The present application provides a soil remediation agent containing recycled construction waste, specifically comprising the following components in parts by weight: 1.5-2.5 parts of recycled construction waste, 0.1-0.3 parts of minerals, and 0.6-1.0 parts of modified kaolin;

[0007] The method for preparing the construction waste resource-processed product comprises: purifying the construction waste through magnetic separation and air separation, crushing the construction waste, then pyrolyzing the waste at 400-600° C. for 2-4 hours, soaking the waste in an activation solution for 24-36 hours, filtering, drying, and grinding the waste to obtain the product; the activation solution comprises the following components in the following concentrations: 10-20 g / L calcium chloride, 0.5-2 g / L magnesium sulfate, 5-10 g / L citric acid, and the solvent is water;

[0008] The modified kaolin is prepared by uniformly mixing 900-1100 parts by weight of kaolin, 8-16 parts by weight of corn starch, and 500 parts by weight of water, adding 1-3 parts by weight of composite bacteria, mixing uniformly, fermenting, drying, and grinding to obtain the modified kaolin; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.2-0.8;

[0009] The minerals are selected from one or more of potash ore powder, phosphate rock powder and dolomite powder.

[0010] The construction waste referred to in this application refers to waste generated by the construction of buildings, such as concrete, gravel, cement, etc., preferably primarily composed of silicates. In addition to the concrete, gravel, cement, etc., this construction waste may also contain other components, such as dirt and dust, which are often mixed with waste. Construction waste collected from construction sites can generally be used directly as raw material for this application.

[0011] After pyrolysis and resource utilization treatment with activation liquid, construction waste can be converted into useful materials such as recycled aggregates, which can effectively improve the structure of the soil, enhance its permeability, and contribute to the growth and development of plant roots; at the same time, it can release the nutrients required by plants, such as phosphorus and calcium, to promote plant growth; and modified kaolin can improve the water retention capacity of the soil, which is beneficial to plant growth; in addition, the addition of construction waste resource treatment products may provide a suitable living environment for microorganisms, thereby promoting their activity and reproduction.

[0012] Kaolin and cornstarch, after fermentation, can be used as soil remediation agents to improve soil texture. Kaolin has excellent adsorption and ion exchange properties, and these properties are further enhanced after fermentation. It can bind to or exchange harmful substances in the soil, thereby reducing the content of toxic metal ions and pollutants, and improving soil texture. During the fermentation process, cornstarch is broken down into small organic molecules such as sugars and amino acids, which are easily absorbed and utilized by plants. Simultaneously, the fermentation process produces a large number of microorganisms and enzymes that further decompose organic matter in the soil, releasing more nutrients and thus enhancing soil fertility. Furthermore, fermented kaolin and cornstarch promote soil microbial activity: Fermented kaolin and cornstarch provide a rich source of carbon and energy for soil microorganisms, promoting their growth and reproduction. These microorganisms perform important ecological functions in the soil, such as decomposing organic matter, converting nutrients, and inhibiting pathogens, thereby maintaining the soil's ecological balance. The fermented products also improve soil water retention: they increase the organic matter content in the soil, improve the soil structure, and make it more porous. This structure facilitates water retention and infiltration, improving soil water retention.

[0013] This application uses a specific amount of minerals and the above-mentioned construction waste resource treatment products and modified kaolin as effective ingredients to prepare a soil remediation agent, which is used in rice fields contaminated by heavy metal cadmium. It can effectively reduce the effective cadmium content in the soil and the cadmium content in brown rice, thereby improving the production safety of plant cultivation and effectively increasing plant yields.

[0014] This application aims to efficiently utilize construction waste and convert it into a soil remediation agent. The soil remediation agent provided, which contains construction waste resource treatment products, can be used to treat heavy metal contaminated soil. The application scenarios include but are not limited to soil remediation projects in agricultural land, industrial waste land, and around mining areas.

[0015] Preferably, the soil remediation agent containing construction waste resource treatment products comprises the following components in parts by weight: 1.8-2.2 parts of construction waste resource treatment products, 0.15-0.25 parts of minerals, and 0.7-0.9 parts of modified kaolin.

[0016] Preferably, the preparation method of the construction waste resource treatment product is: the construction waste is purified by magnetic separation and air separation, crushed and sieved, then pyrolyzed at 450-550°C for 2.5-3.5h, soaked in activation liquid for 28-32h, filtered, dried and ground to obtain the product.

[0017] Preferably, the activation solution is composed of components with the following concentrations: 12-18 g / L calcium chloride, 1-1.5 g / L magnesium sulfate, 6-9 g / L citric acid, and the solvent is water.

[0018] Preferably, the preparation method of the modified kaolin is as follows: 950-1050 parts by weight of kaolin, 10-12 parts by weight of corn starch, and 500 parts by weight of water are mixed evenly, 1.5-2.5 parts by weight of composite bacteria are added, mixed evenly, fermented, dried, and ground to obtain the modified kaolin.

[0019] Preferably, the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.4-0.6.

[0020] Preferably, the process parameters of the fermentation are: fermentation temperature of 45-60° C., humidity of 20-80%, pH of 5-10, and fermentation time of 96-144 h.

[0021] Preferably, the mineral material is composed of a mixture of potash ore powder and dolomite powder in a weight ratio of 9:0.5-1.5.

[0022] In a second aspect, the present application provides a method for preparing the soil remediation agent comprising construction waste resource-processed products, which specifically comprises the following steps in sequence:

[0023] Weigh the corresponding weight of each raw material component respectively, mix them evenly, grind them and sieve them to obtain the product.

[0024] In a third aspect, the present application provides the use of the soil remediation agent containing construction waste resource-processed products in soil remediation.

[0025] In summary, the technical solution of this application has the following effects:

[0026] Compared with traditional soil remediation methods, using construction waste resource-processed products as soil remediation agents is not only environmentally friendly but also relatively low-cost; this method achieves waste recycling, reduces the demand for new resources, and also helps reduce environmental pollution.

[0027] This application prepares a soil remediation agent by recycling construction waste and using it as active ingredients, minerals, and modified kaolin. On the one hand, it can effectively reduce environmental pollution and waste disposal costs; on the other hand, the preparation cost of the prepared soil remediation agent is significantly reduced, and it can effectively reduce the effective cadmium content in the soil and the cadmium content in brown rice, thereby improving the production safety of rice cultivation and effectively increasing rice yield. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in this application.

[0029] Phosphate rock powder (item number 11-08) and potash rock powder (item number 10-56) were purchased from Shandong Jinyu Chemical Co., Ltd.; dolomite powder (item number St3544) was purchased from Lingshou County Shuntian Mineral Products Processing Plant; kaolin (item number G01) was purchased from Lingshou County Rongbang Mineral Products Processing Plant; corn starch (CAS number 23-66-9, density 4 g / cm 3 ) was purchased from Jinan Hongtu Chemical Co., Ltd.; Bacillus subtilis (effective viable count of 20 billion CFU / g), Bacillus amyloliquefaciens (product number 009, effective viable count of 20 billion CFU / g), and Bacillus laterosporus (effective viable count of 10 billion CFU / g) were purchased from Weifang Yihao Biotechnology Co., Ltd.

[0030] Example

[0031] Examples 1-5

[0032] Examples 1-5 each provide a soil remediation agent.

[0033] The difference between the above embodiments is that the dosage of each component in the soil remediation agent is different, as shown below.

[0034] In Example 1: 2 kg of construction waste resource-processed materials, 0.2 kg of minerals, and 0.8 kg of modified kaolin.

[0035] In Example 2: 1.8 kg of construction waste resource-processed materials, 0.25 kg of minerals, and 0.7 kg of modified kaolin.

[0036] In Example 3: 2.2 kg of construction waste resource-processed materials, 0.15 kg of minerals, and 0.9 kg of modified kaolin.

[0037] In Example 4: 1.5 kg of construction waste resource-processed materials, 0.3 kg of minerals, and 0.6 kg of modified kaolin.

[0038] In Example 5: 2.5 kg of construction waste resource-processed materials, 0.1 kg of minerals, and 1.0 kg of modified kaolin.

[0039] The preparation method of the soil remediation agent in the above embodiment is:

[0040] The preparation method of resource-processed construction waste is as follows: the construction waste is purified by magnetic separation to remove metal impurities and air separation to separate light waste, crushed to a particle size of less than 20 mesh, then pyrolyzed at 500°C for 3 hours, soaked in an activation solution for 30 hours, filtered, dried in an oven at 120°C, and ground to a particle size of less than 80 mesh, to obtain the activated solution; the activation solution is composed of the following components in the following concentrations: 15g / L calcium chloride, 1.2g / L magnesium sulfate, 7.5g / L citric acid, and the solvent is water.

[0041] The preparation method of modified kaolin is as follows: 1000g kaolin, 11g corn starch and 50g water are mixed evenly, 2g composite bacteria are added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.5.

[0042] The preparation method of the soil remediation agent is as follows: weigh the corresponding weights of the raw material components, construction waste resource treatment products, minerals (the minerals are composed of a mixture of potassium ore powder and dolomite powder with a weight ratio of 9:1), and modified kaolin, mix them evenly, grind them to a particle size of less than 80 mesh, and sieve them to obtain the obtained product.

[0043] Examples 6-9

[0044] Examples 6-9 each provide a soil remediation agent.

[0045] The difference between the above embodiment and embodiment 1 is that the preparation method of the construction waste resource treatment product is different, as shown below.

[0046] In Example 6: In the method for preparing construction waste resource recovery products, the activation solution is composed of the following components at the following concentrations: 10 g / L calcium chloride, 2 g / L magnesium sulfate, 10 g / L citric acid, and the solvent is water.

[0047] In Example 7: In the method for preparing construction waste resource treatment products, the activation solution is composed of the following components at the following concentrations: 20 g / L calcium chloride, 0.5 g / L magnesium sulfate, 5 g / L citric acid, and the solvent is water.

[0048] In Example 8: In the method for preparing construction waste resource treatment products, the activation solution is composed of the following components in the following concentrations: 12 g / L calcium chloride, 1.5 g / L magnesium sulfate, 6 g / L citric acid, and the solvent is water.

[0049] In Example 9: In the method for preparing construction waste resource recovery products, the activation solution is composed of the following components at the following concentrations: 18 g / L calcium chloride, 1 g / L magnesium sulfate, 9 g / L citric acid, and the solvent is water.

[0050] The other process parameters in the above embodiment are the same as those in Example 1.

[0051] Examples 10-13

[0052] Examples 10-13 each provide a soil remediation agent.

[0053] The difference between the above embodiment and embodiment 1 is that the types of minerals are different, as shown below.

[0054] In Example 10, the mineral material is composed of a mixture of phosphate rock powder and dolomite powder in a weight ratio of 9:1.

[0055] In Example 11, the mineral material is composed of a mixture of potash ore powder and dolomite powder in a weight ratio of 1:9.

[0056] In Example 12, the mineral material is a mixture of potash ore powder and dolomite powder in a weight ratio of 9:0.5.

[0057] In Example 13, the mineral material is a mixture of potash ore powder and dolomite powder in a weight ratio of 9:1.5.

[0058] The other process parameters in the above embodiment are the same as those in Example 1.

[0059] Examples 14-18

[0060] Examples 14-18 each provide a soil remediation agent.

[0061] The difference between the above embodiment and embodiment 1 is that the preparation method of the modified kaolin is different, as shown below.

[0062] In Example 14: The preparation method of modified kaolin is as follows: 800g of kaolin, 25g of corn starch, and 50g of water are mixed evenly, 4g of composite bacteria are added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.5.

[0063] In Example 15: The preparation method of modified kaolin is as follows: 1200g kaolin, 5g corn starch, and 50g water are mixed evenly, 0.5g composite bacteria are added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.5.

[0064] In Example 16: The preparation method of modified kaolin is as follows: 1000g kaolin, 11g corn starch, and 50g water are mixed evenly, 2g of composite bacteria are added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria are composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:7.

[0065] In Example 17: The preparation method of modified kaolin is as follows: 900g kaolin, 16g corn starch, and 50g water are mixed evenly, 3g of composite bacteria are added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.2.

[0066] In Example 18: The preparation method of modified kaolin is as follows: 1100g kaolin, 8g corn starch, and 50g water are mixed evenly, 1g of composite bacteria is added, mixed evenly, and fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, and fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 mesh; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.8.

[0067] The other process parameters in the above embodiment are the same as those in Example 1.

[0068] Comparative Example

[0069] Comparative Example 1-2

[0070] Comparative Examples 1-2 each provide a soil remediation agent.

[0071] The difference between the comparative example and Example 1 is that the dosage of each component in the soil remediation agent is different, as shown below.

[0072] In Comparative Example 1: 3 kg of construction waste resource processing materials, 0.05 kg of minerals, and 1.2 kg of modified kaolin.

[0073] In Comparative Example 2: 1.2 kg of construction waste resource-processed materials, 0.3 kg of minerals, and 0.4 kg of modified kaolin.

[0074] The other process parameters in the above comparative example are the same as those in Example 1.

[0075] Comparative Examples 3-5

[0076] Comparative Examples 3-5 each provide a soil remediation agent.

[0077] The differences between the comparative example and Example 1 are as follows.

[0078] In Comparative Example 3: In the preparation method of construction waste resource treatment product: 7.5g / L citric acid aqueous solution is used as the activation solution.

[0079] In Comparative Example 4: In the method for preparing the resource-processed construction waste, an aqueous solution containing 1.2 g / L calcium chloride, 15 g / L magnesium sulfate, and 7.5 g / L citric acid is used as the activation solution.

[0080] In Comparative Example 5: In the preparation method of modified kaolin, the composite bacteria consisted of a mixture of Bacillus subtilis and Bacillus licheniformis in a weight ratio of 10:0.8.

[0081] Performance testing

[0082] A field plot test was adopted. The test base was in a rice field contaminated with heavy metal cadmium (cadmium content was detected before the test). A protection row was set up around the test plot. The soil remediation agents prepared in the embodiment and the comparative example were evenly mixed and sprinkled on the surface of the heavy metal cadmium contaminated soil, 100 kg per mu, and then the soil was plowed to fully mix the soil remediation agent and the soil. The soil heavy metal remediation process was completed after 7 days of balancing.

[0083] The rice variety used for planting is Guangliang Youxiang 66 (approval number: Guoshen Rice 2012028). During the rice planting process, local conventional methods are followed for transplanting rice, managing water, applying fertilizers, preventing and controlling pests and diseases, and harvesting.

[0084] Fertilize one week before transplanting: apply 30 kg of N-P2O5-K2O (26-10-14) blended fertilizer (purchased from Wuhan Chuhong Agricultural Development Co., Ltd.) per mu of paddy field. Fertilize one week after transplanting: apply 6 kg of urea per mu of paddy field during the tillering stage. Fertilize during the heading stage: apply 4 kg of urea and 6 kg of potassium chloride per mu of paddy field.

[0085] (1) Performance test method of rice yield: For the harvested rice, thresh and harvest individually and weigh the rice yield; and use the test area without using soil remediation agent as the control group and weigh the rice yield.

[0086] Test results: as shown in Table 1.

[0087] (2) Performance test method for available cadmium content in soil: Soil samples were collected before the test and after rice harvest, and air-dried indoors. The available cadmium in the soil was determined according to the test method of GB / T 23739-2009, and the cadmium reduction rate of the available cadmium in the soil was calculated.

[0088] The cadmium reduction rate of available cadmium in soil = (available cadmium content in soil after the test - available cadmium content in soil before the test) / available cadmium content in soil before the test × 100%.

[0089] (3) Performance test method for cadmium content in brown rice: Harvested rice is air-dried, ground into rice, and then ground into brown rice flour. The cadmium content of brown rice is measured according to the test method of GB / T5009.15-2014. The cadmium reduction rate of brown rice is calculated using the test area without soil remediation agent as the control group.

[0090] Test results: as shown in Table 1.

[0091] Table 1 Application performance test results of soil remediation agents in Examples and Comparative Examples

[0092]

[0093]

[0094] Combined with Table 1, by comparing the test results of the embodiment and the comparative example, the present application uses construction waste resource processing products, minerals, and modified kaolin as effective ingredients to prepare a soil remediation agent, which is used in rice fields contaminated by heavy metal cadmium. It can effectively reduce the effective cadmium content in the soil and the cadmium content in brown rice, thereby improving the production safety of rice cultivation and effectively increasing rice yield.

[0095] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A soil remediation agent containing construction waste resource treatment products, characterized in that: Specifically, it includes the following components in parts by weight: 1.5-2.5 parts of construction waste resource treatment materials, 0.1-0.3 parts of minerals, and 0.6-1.0 parts of modified kaolin; The method for preparing the construction waste resource-processed product comprises: purifying the construction waste through magnetic separation and air separation, crushing the construction waste, then pyrolyzing the waste at 400-600° C. for 2-4 hours, soaking the waste in an activation solution for 24-36 hours, filtering, drying, and grinding the waste to obtain the product; the activation solution comprises the following components in the following concentrations: 10-20 g / L calcium chloride, 0.5-2 g / L magnesium sulfate, 5-10 g / L citric acid, and the solvent is water; The modified kaolin is prepared by uniformly mixing 900-1100 parts by weight of kaolin, 8-16 parts by weight of corn starch, and 500 parts by weight of water, adding 1-3 parts by weight of composite bacteria, mixing uniformly, fermenting, drying, and grinding to obtain the modified kaolin; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.2-0.8; The minerals are selected from one or more of potash ore powder, phosphate rock powder and dolomite powder.

2. The soil remediation agent comprising construction waste resource treatment products according to claim 1, characterized in that: Specifically, the invention comprises the following components in parts by weight: 1.8-2.2 parts of construction waste resource treatment materials, 0.15-0.25 parts of minerals, and 0.7-0.9 parts of modified kaolin.

3. The soil remediation agent comprising construction waste resource treatment products according to claim 2, characterized in that: The preparation method of the construction waste resource treatment product is as follows: the construction waste is purified by magnetic separation and air separation, crushed and sieved, then pyrolyzed at 450-550°C for 2.5-3.5h, soaked in activation liquid for 28-32h, filtered, dried and ground to obtain the product.

4. The soil remediation agent comprising construction waste resource treatment products according to claim 1, characterized in that: The activation solution is composed of the following components in the following concentrations: 12-18 g / L calcium chloride, 1-1.5 g / L magnesium sulfate, and 6-9 g / L citric acid, and the solvent is water.

5. The soil remediation agent comprising construction waste resource treatment products according to claim 1, characterized in that: The preparation method of the modified kaolin comprises the following steps: uniformly mixing 950-1050 parts by weight of kaolin, 10-12 parts by weight of corn starch and 500 parts by weight of water, adding 1.5-2.5 parts by weight of composite bacteria, uniformly mixing, fermenting, drying and grinding to obtain the modified kaolin.

6. The soil remediation agent comprising construction waste resource treatment products according to claim 1, characterized in that: The composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.4-0.

6.

7. The soil remediation agent containing construction waste resource treatment products according to claim 1, characterized in that: The process parameters of the fermentation are as follows: fermentation temperature of 45-60° C., humidity of 20-80%, pH of 5-10, and fermentation time of 96-144 hours.

8. The soil remediation agent comprising construction waste resource treatment products according to claim 1, characterized in that: The mineral material is composed of a mixture of potash ore powder and dolomite powder in a weight ratio of 9:0.5-1.

5.

9. The method for preparing a soil remediation agent comprising construction waste resource-processed products according to any one of claims 1 to 8, wherein: Specifically, the following steps are performed in sequence: Weigh the corresponding weight of each raw material component respectively, mix them evenly, grind them and sieve them to obtain the product.

10. Use of the soil remediation agent comprising construction waste resource-processed products according to any one of claims 1 to 8 in soil remediation.

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