Soil remediation agent containing construction waste resourceful treatment substances as well as preparation method and application of soil remediation agent

Abstract

The invention relates to the technical field of soil remediation, and particularly discloses a soil remediation agent containing construction waste resourceful treatment substances as well as a preparation method and application of the soil remediation agent. The soil remediation agent disclosed by the invention is prepared from 1.5 to 2.5 parts of construction waste resourceful treatment substances, 0.1 to 0.3 part of mineral substances and 0.6 to 1.0 part of modified kaolin, the preparation method of the construction waste resourceful treatment substance comprises the following steps: performing magnetic separation and winnowing purification on construction waste, crushing, pyrolyzing, soaking in an activating solution, filtering, drying and grinding to obtain the construction waste resourceful treatment substance. A preparation method of the modified kaolin comprises the following steps: uniformly mixing kaolin, corn starch and water, adding compound bacteria, uniformly mixing, fermenting, drying and grinding, thereby obtaining the modified kaolin. The compound bacteria are prepared from bacillus subtilis and bacillus laterosporus. By utilizing the soil remediation agent provided by the invention, the content of available cadmium in soil can be effectively reduced, so that the production safety of plant planting is improved, and the yield of plants can be effectively increased.

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] At present, the global soil pollution problem is serious. With the acceleration of urbanization, chemical pollution and heavy metals such as cadmium, lead, mercury, and arsenic have become the main soil pollutants. Excessive application of fertilizers causes soil acidification, which further activates heavy metal elements in the soil, forming a vicious cycle. Therefore, soil remediation has received attention in the industry. At the same time, a large amount of garbage generated by the construction industry has not been effectively utilized, but instead occupies precious land resources and causes secondary environmental pollution.

[0003] Existing soil remediation technology and building material reuse technology operate independently and lack effective integration strategies. The preparation cost of traditional soil remediation agents is high and the process is complicated, while construction waste is usually randomly piled up or landfilled, which not only wastes resources but also aggravates 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 comprising construction waste resource treatment products, and a preparation method and application thereof.

[0006] The present application provides a soil remediation agent containing construction waste resource treatment products, which specifically includes the following components in parts by weight: 1.5-2.5 parts of construction waste resource treatment products, 0.1-0.3 parts of minerals, and 0.6-1.0 parts of modified kaolin; 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, then pyrolyzed at 400-600°C for 2-4h, soaked in an activation solution for 24-36h, filtered, dried, and ground to obtain the product; the activation solution is composed of the following components in the following concentrations: 10-20g / L calcium chloride, 0.5-2g / L magnesium sulfate, 5-10g / L citric acid, and the solvent is water; The preparation method of the modified kaolin is as follows: 900-1100 parts by weight of kaolin, 8-16 parts by weight of corn starch and 500 parts by weight of water are mixed evenly, 1-3 parts by weight of composite bacteria are added, mixed evenly, fermented, dried and ground 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 ore powder and dolomite powder.

[0007] The construction waste described in this application refers to the waste brought by the main building, such as concrete, gravel, cement, etc., preferably the construction waste mainly composed of silicate. In addition to the concrete, gravel, cement, etc., these construction wastes may contain other components such as soil and dust that are often mixed in the waste. In general, the construction waste collected from the construction site can be directly used as the raw material of this application.

[0008] After pyrolysis and activation liquid resource treatment, 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 help 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.

[0009] Kaolin and corn starch can be used as soil remediation agents after fermentation to improve soil texture. Kaolin has good adsorption and ion exchange capacity. After fermentation, these properties are further enhanced. It can combine or exchange with harmful substances in the soil, thereby reducing the content of toxic metal ions and pollutants in the soil and improving soil texture. Corn starch will be decomposed into small molecular organic matter such as sugars and amino acids during the fermentation process. These small molecular organic matter are easily absorbed and utilized by plants. At the same time, a large number of microorganisms and enzymes will be produced during the fermentation process. They can further decompose organic matter in the soil and release more nutrients, thereby enhancing soil fertility. In addition, it promotes soil microbial activity: fermented kaolin and corn starch provide rich carbon sources and energy for microorganisms in the soil, which is conducive to the growth and reproduction of microorganisms; these microorganisms play an important ecological function in the soil, such as decomposing organic matter, transforming nutrients, inhibiting pathogens, etc., thereby maintaining the ecological balance of the soil; and improve the soil water retention capacity: the fermented products can increase the organic matter content in the soil, improve the soil structure, and make it more loose and porous. This structure is conducive to the retention and penetration of soil moisture and improves the soil's water retention capacity.

[0010] The present application utilizes 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.

[0011] The present application aims to transform construction waste into soil remediation agents through efficient utilization. The soil remediation agents provided, which contain 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.

[0012] 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.

[0013] 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 solution for 28-32h, filtered, dried and ground to obtain.

[0014] 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.

[0015] Preferably, the preparation method of the modified kaolin is: 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.

[0016] 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.

[0017] 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 96-144h.

[0018] Preferably, the mineral material is a mixture of potash ore powder and dolomite powder in a weight ratio of 9:0.5-1.5.

[0019] In a second aspect, the present application provides a method for preparing the soil remediation agent containing construction waste resource treatment products, which specifically comprises the following steps in sequence: Weigh the corresponding weight of each raw material component respectively, mix them evenly, grind them and sieve them to obtain the product.

[0020] In a third aspect, the present application provides the use of the soil remediation agent containing construction waste resource treatment products in soil remediation.

[0021] In summary, the technical solution of this application has the following effects: Compared with traditional soil remediation methods, using construction waste resource processing products as soil remediation agents is not only environmentally friendly but also relatively low-cost; this method realizes the reuse of waste, reduces the demand for new resources, and also helps to reduce environmental pollution.

[0022] The present application prepares a soil remediation agent by recycling construction waste and using minerals and modified kaolin as effective ingredients. 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

[0023] 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 the present application.

[0024] 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 was 20 billion CFU / g), Bacillus amyloliquefaciens (catalog number 009, effective viable count was 20 billion CFU / g), and Bacillus laterosporus (effective viable count was 10 billion CFU / g) were purchased from Weifang Yihao Biotechnology Co., Ltd. Example

[0025] Examples 1-5 Examples 1-5 each provide a soil remediation agent.

[0026] The difference between the above embodiments is that the dosage of each component in the soil remediation agent is different, as shown below.

[0027] In Example 1: 2 kg of construction waste resource-processed materials, 0.2 kg of minerals, and 0.8 kg of modified kaolin.

[0028] In Example 2: 1.8 kg of construction waste resource-processed materials, 0.25 kg of minerals, and 0.7 kg of modified kaolin.

[0029] In Example 3: 2.2 kg of construction waste resource-processed materials, 0.15 kg of minerals, and 0.9 kg of modified kaolin.

[0030] In Example 4: 1.5 kg of construction waste resource processing materials, 0.3 kg of minerals, and 0.6 kg of modified kaolin.

[0031] In Example 5: 2.5 kg of construction waste resource processing materials, 0.1 kg of minerals, and 1.0 kg of modified kaolin.

[0032] The preparation method of the soil remediation agent in the above embodiment is: The preparation method of resource-processed construction waste is as follows: purify the construction waste by removing metal impurities through magnetic separation and separating light waste through air separation, crush it to a particle size of less than 20 mesh, then pyrolyze it at 500°C for 3 hours, soak it in an activation solution for 30 hours, filter it, dry it in an oven at 120°C, and grind it to a particle size of less than 80 mesh, and obtain it; the activation solution is composed of the following concentrations: 15g / L calcium chloride, 1.2g / L magnesium sulfate, 7.5g / L citric acid, and the solvent is water.

[0033] 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, fermented (fermentation temperature is 52°C, humidity is 50-70%, pH is 7.5-8.5, fermentation time is 120h), dried in a 120°C oven, and ground to a particle size of less than 80 meshes; the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus laterosporus in a weight ratio of 10:0.5.

[0034] The preparation method of the soil remediation agent is as follows: weigh the corresponding weights of each raw material component, construction waste resource treatment material, minerals (the minerals are composed of a mixture of potassium ore powder and dolomite powder in 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 soil remediation agent.

[0035] Embodiment 6-9 Examples 6-9 each provide a soil remediation agent.

[0036] The difference between the above embodiment and embodiment 1 is that the preparation method of the resource-processed construction waste is different, as shown below.

[0037] In Example 6: In the method for preparing construction waste resource treatment products, the activation solution is composed of the following components in the following concentrations: 10 g / L calcium chloride, 2 g / L magnesium sulfate, 10 g / L citric acid, and the solvent is water.

[0038] In Example 7: In the method for preparing construction waste resource treatment products, the activation solution is composed of the following components in the following concentrations: 20 g / L calcium chloride, 0.5 g / L magnesium sulfate, 5 g / L citric acid, and the solvent is water.

[0039] 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.

[0040] In Example 9: In the method for preparing construction waste resource treatment products, the activation solution is composed of the following components in the following concentrations: 18 g / L calcium chloride, 1 g / L magnesium sulfate, 9 g / L citric acid, and the solvent is water.

[0041] The other process parameters in the above embodiment are the same as those in embodiment 1.

[0042] Examples 10-13 Examples 10-13 each provide a soil remediation agent.

[0043] The difference between the above embodiment and embodiment 1 is that the types of minerals are different, as shown below.

[0044] 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.

[0045] In Example 11: the mineral material is a mixture of potash ore powder and dolomite powder in a weight ratio of 1:9.

[0046] In Example 12: the mineral material is a mixture of potash ore powder and dolomite powder in a weight ratio of 9:0.5.

[0047] In Example 13: the mineral material is composed of a mixture of potash ore powder and dolomite powder in a weight ratio of 9:1.5.

[0048] The other process parameters in the above embodiment are the same as those in embodiment 1.

[0049] Examples 14-18 Examples 14-18 each provide a soil remediation agent.

[0050] The difference between the above embodiment and embodiment 1 is that the preparation method of modified kaolin is different, as shown below.

[0051] In Example 14: The preparation method of modified kaolin is as follows: 800g kaolin, 25g corn starch, and 50g 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 an oven at 120°C, 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.

[0052] 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 an oven at 120°C, 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.

[0053] 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 an oven at 120°C, 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 10:7.

[0054] 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 an oven at 120°C, 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.

[0055] 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 an oven at 120°C, 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.

[0056] The other process parameters in the above embodiment are the same as those in embodiment 1.

[0057] Comparative Example Comparative Example 1-2 Comparative Examples 1-2 respectively provide a soil remediation agent.

[0058] 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.

[0059] In Comparative Example 1: 3 kg of construction waste resource treatment products, 0.05 kg of minerals, and 1.2 kg of modified kaolin.

[0060] In Comparative Example 2: 1.2 kg of construction waste resource treatment products, 0.3 kg of minerals, and 0.4 kg of modified kaolin.

[0061] The other process parameters in the above comparative example are the same as those in Example 1.

[0062] Comparative Examples 3-5 Comparative Examples 3-5 each provide a soil remediation agent.

[0063] The difference between the above comparative example and Example 1 is as follows.

[0064] In Comparative Example 3: In the method for preparing construction waste resource treatment products: a 7.5 g / L citric acid aqueous solution is used as the activation solution.

[0065] In Comparative Example 4: In the method for preparing construction waste resource treatment products: 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 an activation solution.

[0066] In Comparative Example 5: In the preparation method of modified kaolin, the composite bacteria is composed of a mixture of Bacillus subtilis and Bacillus licheniformis in a weight ratio of 10:0.8.

[0067] Performance testing A field plot test was adopted. The test base was in a rice field contaminated with heavy metal cadmium (the cadmium content was detected before the test). A protection row was set up around the test plot. The soil remediation agent prepared in the embodiment and the comparative example was 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 make the soil remediation agent and the soil fully mixed and evenly mixed. The soil heavy metal remediation process was completed after 7 days of balance.

[0068] The rice variety used was Guangliang Youxiang 66 (approval number: Guoshen Rice 2012028). During the rice planting process, rice was transplanted, water was managed, fertilized, pests and diseases were controlled, and harvested according to local conventional methods.

[0069] Fertilize one week before rice transplanting: 30kg of mixed fertilizer N-P2O5-K2O (26-10-14) per mu of rice field (mixed fertilizer purchased from Wuhan Chuhong Agricultural Development Co., Ltd.). Fertilize one week after rice transplanting: 6kg of urea per mu of rice field during the rice tillering stage. Fertilize during the rice heading stage: 4kg of urea and 6kg of potassium chloride per mu of rice field.

[0070] (1) Performance test method of rice yield: For the harvested rice, the rice yield is measured separately; and the test area without using soil remediation agent is used as the control group to weigh the rice yield.

[0071] Test results: as shown in Table 1.

[0072] (2) Performance test of soil available cadmium content Test method: Soil samples were collected before the test and after rice harvest, and air-dried indoors. According to the test method of GB / T 23739-2009, the soil available cadmium was measured and the cadmium reduction rate of the soil available cadmium was calculated.

[0073] 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%.

[0074] (3) Performance test of cadmium content in brown rice Test method: The 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; and the test area without soil remediation agent is used as the control group to calculate the cadmium reduction rate of brown rice.

[0075] Test results: as shown in Table 1.

[0076] Table 1 Application performance test results of soil remediation agents in examples and comparative examples Combined with Table 1, by comparing the test results of the embodiments and the comparative examples, 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.

[0077] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

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 material, 0.1-0.3 parts of minerals, and 0.6-1.0 parts of modified kaolin; 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, then pyrolyzed at 400-600°C for 2-4h, soaked in an activation solution for 24-36h, filtered, dried, and ground to obtain the product; the activation solution is composed of the following components in the following concentrations: 10-20g / L calcium chloride, 0.5-2g / L magnesium sulfate, 5-10g / L citric acid, and the solvent is water; The preparation method of the modified kaolin is as follows: 900-1100 parts by weight of kaolin, 8-16 parts by weight of corn starch and 500 parts by weight of water are mixed evenly, 1-3 parts by weight of composite bacteria are added, mixed evenly, fermented, dried and ground 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 ore powder and dolomite powder.

2. The soil remediation agent containing 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 containing 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 an activation solution for 28-32h, filtered, dried and ground to obtain the product.

4. The soil remediation agent containing construction waste resource treatment products according to claim 1, characterized in that: 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.

5. The soil remediation agent containing construction waste resource treatment products according to claim 1, characterized in that: 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.

6. The soil remediation agent containing 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 96-144h.

8. The soil remediation agent containing construction waste resource treatment products according to claim 1, characterized in that: The mineral material is 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 treatment products according to any one of claims 1 to 8, characterized in that: 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 treatment products as claimed in any one of claims 1 to 8 in soil remediation.

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