Coal-based solid waste composite material, application thereof and soil remediation method

Abstract

The invention provides a coal-based solid waste composite material and application thereof, and belongs to the technical field of soil remediation. The coal-based solid waste composite material is successfully prepared from 400 to 600 parts of desulfurized gypsum, 100 to 300 parts of fly ash, 100 to 300 parts of wood fiber, 80 to 120 parts of humic acid, 10 to 30 parts of sodium silicate, 8 to 12 parts of EDTA (Ethylene Diamine Tetraacetic Acid), 8 to 12 parts of citric acid and 10 to 30 parts of hydroxyapatite, so that the problem that a soil remediation agent in the prior art cannot solve the high-concentration heavy metal combined pollution condition is solved, and the remediation effect is improved. According to the coal-based solid waste composite material and the soil remediation method, the release amount of various high-concentration heavy metals in polluted soil can be effectively reduced, the properties of the soil are not affected, and the coal-based solid waste composite material and the soil remediation method can be used for follow-up crop cultivation, achieve long-term remediation of the soil and have wide application value and development potential.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and in particular to a coal-based solid waste composite material and an application thereof, and a soil remediation method. Background Art

[0002] As an indispensable non-renewable resource for human beings, soil is the material basis for human survival. In recent decades, with the rapid growth of the global population, energy development, industrial construction and urbanization have also developed at an alarming rate. Global industrialization has led to the discharge of a large number of potentially toxic compounds into the environment, including heavy metals. According to statistics, in the past 50 years, the global discharge of Cd into the environment reached 220,000 tons, Cu 939,000 tons, Pb 783,000 tons and Zn 1.35 million tons, of which a considerable part directly or indirectly entered the soil environment, thus polluting the soil environment in some areas, thus destroying the normal function of the local ecosystem and causing harm to human health. At the same time, heavy metal pollution has the characteristics of long incubation period, great harm and difficulty to be detected by people. Moreover, once heavy metals form pollution, it is not easy to remove from the environment and has strong stubbornness. Therefore, heavy metals are often listed as one of the types of pollutants that need to be treated first. The heavy metal pollution in the soil caused by the production of various industrial enterprises is more long-term and hidden. The accumulation of heavy metals in the farmland around the enterprises not only reduces the yield and quality of agricultural products, but may also act on the surface and groundwater of the contaminated area through runoff and leaching, causing the deterioration of the ecological environment in the entire region and ultimately endangering human health.

[0003] Soil remediation is based on the traditional soil chemistry and other branch scientific systems, and draws on the theoretical foundations, methods and techniques of related disciplines such as soil ecology, soil chemistry, agricultural chemistry, plant nutrition, environmental chemistry, and environmental engineering. It has gradually developed into a soil branch discipline with polluted areas, pollution characteristics, pollution risk prediction and assessment, soil pollution control and remediation technology research and development, integrated management and biological resource disposal as its core research content.

[0004] Heavy metals refer to a large class of elements that are of great significance in industrial production and biological effects. They generally refer to metal elements with a specific gravity greater than 4.0, commonly used in industry, and toxic to organisms, such as Hg, Cd, Pb, As, and Cr. Heavy metals in the environment have some significant common behavioral characteristics, which are different from organic compounds. At the same time, the remediation mechanism and technology of heavy metal-contaminated soil also have significant characteristics. Soil heavy metal pollution refers to the process in which the amount of heavy metals entering the soil exceeds its content in the soil itself and the environmental capacity of the soil due to human activities, thereby causing changes in the composition and physical and chemical properties of the soil. When the ecological balance of the soil itself is destroyed, the natural function and soil quality of the soil will deteriorate. The main ways for heavy metals to contaminate soil are irrigation of farmland with polluted wastewater and natural sedimentation of heavy metal dust. Heavy metals in soil not only endanger human health through agricultural products, groundwater, etc. through the food chain, but also have the characteristics of being able to stably fix to the soil and difficult to migrate, and then show the accumulation of pollution and strong regionality.

[0005] Soil contaminated by heavy metals is often repaired using physical, chemical and biological techniques, which often achieve good results.

[0006] Chinese patent CN109020748A discloses a heavy metal soil remediation agent, which is composed of struvite, bone meal, and apatite. It can increase the soil pH value, passivate heavy metals, reduce the activity of heavy metals, and improve soil production capacity. In addition, the preparation method of the soil remediation agent is simple, the preparation cost is low, and it has a high value for promotion and application.

[0007] Chinese patent CN106221701A discloses a heavy metal soil remediation agent, which includes the following raw materials by weight: 15-25 parts of activated carbon fiber; 5-12 parts of amino polycarboxylic acid; 5-10 parts of organic acid; 3-10 parts of organic matter; 2-8 parts of biological emulsifier; 1-5 parts of sodium lignin sulfonate. The soil remediation agent proposed in this invention has a reasonable formula and a simple preparation method. It can effectively reduce various heavy metal pollutants in the soil, improve the permeability of soil air, and improve the growth environment of crops. At the same time, it is environmentally friendly and green.

[0008] However, the soil remediation agents in the above-mentioned prior art cannot achieve high concentrations of complex heavy metal pollution, and the remediation effect needs to be improved. Summary of the invention

[0009] The purpose of the present invention is to provide a coal-based solid waste composite material and its application and a method for remediating soil heavy metal pollution, which have excellent remediation effects, based on a large amount of basic research in the early stage.

[0010] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0011] The present invention provides a coal-based solid waste composite material, comprising the following components in parts by weight:

[0012] 400-600 parts of desulfurized gypsum, 100-300 parts of fly ash, 100-300 parts of wood fiber, 80-120 parts of humic acid, 10-30 parts of sodium silicate, 8-12 parts of EDTA, 8-12 parts of citric acid and 10-30 parts of hydroxyapatite.

[0013] Preferably, the following components are included in parts by weight:

[0014] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite.

[0015] Preferably, the coal-based solid waste composite material also includes microbial agents.

[0016] Preferably, the weight proportion of the microbial agent in the coal-based solid waste composite material is 40 to 60 parts.

[0017] Preferably, the weight proportion of the microbial agent in the coal-based solid waste composite material is 50 parts.

[0018] Preferably, the microbial agent contains jelly-like Bacillus.

[0019] Preferably, the live bacteria concentration of the jelly-like Bacillus in the microbial agent is 10 7 ~10 10 CFU / mL.

[0020] The present invention also provides the use of the above-mentioned coal-based solid waste composite material in the remediation of heavy metal contaminated soil.

[0021] The present invention also provides a soil remediation method, comprising the following steps:

[0022] The coal-based solid waste composite material is mixed with uncontaminated soil to obtain a repair substrate;

[0023] The repair substrate is mixed with the heavy metal contaminated soil to be repaired to carry out soil passivation repair.

[0024] Preferably, the weight ratio of the coal-based solid waste composite material to the uncontaminated soil is 1:50 to 150;

[0025] The weight ratio of the repair substrate to the heavy metal contaminated soil to be repaired is 1:10-50.

[0026] Technical effects and advantages of the present invention:

[0027] The present invention adopts 400-600 parts of desulfurized gypsum, 100-300 parts of fly ash, 100-300 parts of wood fiber, 80-120 parts of humic acid, 10-30 parts of sodium silicate, 8-12 parts of EDTA, 8-12 parts of citric acid and 10-30 parts of hydroxyapatite, and successfully obtains a coal-based solid waste composite material, which can not only effectively reduce the content of multiple high-concentration heavy metals in contaminated soil, but also does not affect the properties of the soil itself, can be used for subsequent crop cultivation, realize long-term soil restoration, and has wide application value and development potential. DETAILED DESCRIPTION

[0028] The present invention provides a coal-based solid waste composite material, comprising the following components in parts by weight:

[0029] 400-600 parts of desulfurized gypsum, 100-300 parts of fly ash, 100-300 parts of wood fiber, 80-120 parts of humic acid, 10-30 parts of sodium silicate, 8-12 parts of EDTA, 8-12 parts of citric acid and 10-30 parts of hydroxyapatite; preferably, the following components in parts by weight: 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite.

[0030] In the present invention, preferably, the coal-based solid waste composite material further comprises a microbial agent; preferably, the weight proportion of the microbial agent in the coal-based solid waste composite material is 50 parts; preferably, the microbial agent contains jelly-like Bacillus; preferably, the live bacteria concentration of jelly-like Bacillus in the microbial agent is 10 7 ~10 10 CFU / mL.

[0031] The present invention also provides the use of the above-mentioned coal-based solid waste composite material in the remediation of heavy metal contaminated soil; the heavy metal contamination of the soil mainly includes the following sources:

[0032] (1) Heavy metal particle deposition in the atmosphere

[0033] Heavy metals in the atmosphere mainly come from industrial and mining, metallurgical production, and vehicle exhaust emissions containing metal dust, which are mainly distributed around metallurgical enterprises, along highways and railways, etc. They enter the soil environment through natural sedimentation or precipitation, and are mainly distributed around industrial and mining and metallurgical enterprises in the suburban areas. The concentration decreases as it spreads from cities to rural areas.

[0034] (2) Sewage irrigation

[0035] After being treated in sewage treatment plants, urban domestic sewage is used to irrigate farmland, grassland or forest land through ditches to achieve sewage irrigation. After industrial wastewater in some areas is mixed with domestic sewage, it contains a large amount of heavy metal ions. Without treatment for a long time, it directly leaches into the soil environment, causing heavy metal pollution in the soil. In the last century, heavy metal pollution in northern my country was already quite serious due to long-term sewage irrigation.

[0036] (3) Accumulation of solid waste containing heavy metals

[0037] Tailings generated during mining and metallurgical production are the main source of solid waste in mines. After the coarse ore undergoes flotation and chemical separation in the mine, a large amount of mineral processing reagents remain in the tailings, and the tailings rich in heavy metals accumulate in the tailings dam. When precipitation occurs, the heavy metals in the tailings will enter the surrounding soil layer with surface runoff or seep into the ground due to leaching, polluting the groundwater.

[0038] (4) Application of fertilizers, pesticides and plastic films

[0039] Long-term use of pesticides containing heavy metals such as Pb, Cd, Hg, As, etc. and excessive application of chemical fertilizers may lead to excessive heavy metal content in farmland soil. Among commonly used chemical fertilizers, phosphate fertilizers contain more heavy metals, while nitrogen fertilizers and potassium fertilizers contain relatively less. The Cd content in phosphate fertilizers and some other compound fertilizers reaches 400 mg / kg. Long-term excessive application of chemical fertilizers will cause the accumulation of heavy metals in the soil and lead to heavy metal pollution. The plastic film used in agricultural greenhouses uses heat stabilizers containing Cd and Pb. When it is not properly recovered and left in the farmland soil, it causes soil heavy metal pollution.

[0040] The present invention also provides a soil remediation method, comprising the following steps: mixing the above-mentioned coal-based solid waste composite material with uncontaminated soil to obtain a remediation substrate; mixing the remediation substrate with the heavy metal contaminated soil to be remediated to perform soil remediation; preferably, the weight ratio of the coal-based solid waste composite material to the uncontaminated soil is 1:50 to 150; the weight ratio of the remediation substrate to the heavy metal contaminated soil to be remediated is 1:10 to 50.

[0041] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0042] Example 1

[0043] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution used was 10 8CFU / mL, that is, coal-based solid waste composite materials.

[0044] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0045] Example 2

[0046] 400 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 200 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0047] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0048] Example 3

[0049] 600 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0050] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0051] Example 4

[0052] 500 parts of desulfurized gypsum, 100 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution used was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0053] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0054] Example 5

[0055] 500 parts of desulfurized gypsum, 300 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution used was 108 CFU / mL, that is, coal-based solid waste composite materials.

[0056] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0057] Example 6

[0058] 500 parts of desulfurized gypsum, 200 parts of fly ash, 100 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution used was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0059] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0060] Example 7

[0061] 500 parts of desulfurized gypsum, 200 parts of fly ash, 300 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0062] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0063] Example 8

[0064] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 80 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0065] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0066] Example 9

[0067] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 120 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0068] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0069] Example 10

[0070] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 15 parts of sodium silicate, 12 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0071] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0072] Embodiment 11

[0073] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 25 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution used was 10 9 CFU / mL, that is, coal-based solid waste composite materials.

[0074] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0075] Example 12

[0076] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 12 parts of EDTA, 12 parts of citric acid and 25 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0077] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0078] Embodiment 13

[0079] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 8 parts of EDTA, 12 parts of citric acid and 25 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0080] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0081] Embodiment 14

[0082] 600 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 12 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 40 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0083] The obtained coal-based solid waste composite material is mixed into 120 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0084] Embodiment 15

[0085] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 60 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0086] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0087] Comparative Example 1

[0088] 500 parts of desulfurized gypsum, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The live bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0089] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0090] Comparative Example 2

[0091] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate and 20 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution used was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0092] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0093] Comparative Example 3

[0094] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 50 parts of Bacillus megaterium liquid was added. The concentration of active bacteria of the Bacillus megaterium liquid used was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0095] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0096] Comparative Example 4

[0097] A mixture of 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite produces a coal-based solid waste composite material.

[0098] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0099] Comparative Example 5

[0100] 100 parts of desulfurized gypsum, 200 parts of fly ash, 300 parts of wood fiber, 200 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 100 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0101] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0102] Comparative Example 6

[0103] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 10 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution used was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0104] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0105] Comparative Example 7

[0106] 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite were mixed, and 100 parts of jelly-like Bacillus bacterial solution were added. The active bacterial concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0107] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0108] Comparative Example 8

[0109] Add 50 parts of jelly-like Bacillus bacterial solution to 500 parts of desulfurized gypsum. The concentration of active bacteria in the jelly-like Bacillus bacterial solution is 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0110] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0111] Comparative Example 9

[0112] 500 parts of desulfurized gypsum, 200 parts of fly ash and 100 parts of hydroxyapatite were mixed, and 50 parts of jelly-like Bacillus bacterial solution were added. The live bacteria concentration of the jelly-like Bacillus bacterial solution was 10 8 CFU / mL, that is, coal-based solid waste composite materials.

[0113] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0114] Comparative Example 10

[0115] 500 parts of desulfurized gypsum, 400 parts of fly ash, 200 parts of wood fiber, 50 parts of citric acid and 50 parts of hydroxyapatite were mixed, and 20 parts of jelly-like Bacillus bacterial solution were added. The active bacteria concentration of the jelly-like Bacillus bacterial solution was 108 CFU / mL, that is, coal-based solid waste composite materials.

[0116] The obtained coal-based solid waste composite material is mixed into 100 times the weight of soil for use in the remediation of heavy metal contaminated soil.

[0117] Experimental example

[0118] The soil (containing no heavy metals) mixed with coal-based solid waste composite materials of Examples 1 to 5 and Comparative Examples 1 to 10 was used as the repair substrate, and the Cu, As, and Cd composite contaminated soil (Cu: 325.04 mg / kg, As: 409.25 mg / kg, Cd: 43.19 mg / kg) was repaired. The mixing weight ratio of the repair substrate and the soil to be repaired was 1:20, and it was placed at room temperature for one week. After one week, the content of Cu, As, and Cd in the repaired soil was detected by X-ray fluorescence spectrometry. Each group of experiments was performed 3 times in parallel. The results are shown in Tables 1 to 3 below:

[0119] Table 1 Heavy metal Cu content test results (unit: mg / kg)

[0120] Sample 1 Sample 2 Sample 3 Example 1 9.31 9.51 9.95 Example 2 1.24 1.81 1.24 Example 3 9.11 9.04 9.3 Example 4 0.61 1.31 1.09 Example 5 2.98 3.03 2.79 Comparative Example 1 103.12 96.39 104.53 Comparative Example 2 121.52 124.68 112.3 Comparative Example 3 111.48 109.85 111.9 Comparative Example 4 137.02 144.34 146.29 Comparative Example 5 130.98 124.25 124.53 Comparative Example 6 187.69 187.61 183.08 Comparative Example 7 186.44 192.99 195.87 Comparative Example 8 196.96 206.73 201.67 Comparative Example 9 177.13 179.53 177.04 Comparative Example 10 151.24 147.04 151.26

[0121] Table 2 Heavy metal As content test results (unit: mg / kg)

[0122]

[0123]

[0124] Table 3 Heavy metal Cd content test results (unit: mg / kg)

[0125]

[0126]

[0127] The measurement results show that the coal-based solid waste composite material provided by the embodiment of the present invention can achieve the best soil heavy metal remediation effect.

[0128] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A coal-based solid waste composite material, characterized in that: The composition comprises the following components in parts by weight: 400-600 parts of desulfurized gypsum, 100-300 parts of fly ash, 100-300 parts of wood fiber, 80-120 parts of humic acid, 10-30 parts of sodium silicate, 8-12 parts of EDTA, 8-12 parts of citric acid and 10-30 parts of hydroxyapatite.

2. The coal-based solid waste composite material according to claim 1, characterized in that: The composition comprises the following components in parts by weight: 500 parts of desulfurized gypsum, 200 parts of fly ash, 200 parts of wood fiber, 100 parts of humic acid, 20 parts of sodium silicate, 10 parts of EDTA, 10 parts of citric acid and 20 parts of hydroxyapatite.

3. The coal-based solid waste composite material according to claim 1, characterized in that: The coal-based solid waste composite material also includes a microbial agent.

4. The coal-based solid waste composite material according to claim 3, characterized in that: The weight proportion of the microbial agent in the coal-based solid waste composite material is 40 to 60 parts.

5. The coal-based solid waste composite material according to claim 4, characterized in that: The weight proportion of the microbial agent in the coal-based solid waste composite material is 50 parts.

6. The coal-based solid waste composite material according to claim 3, characterized in that: The microbial agent contains jelly-like bacillus.

7. The coal-based solid waste composite material according to claim 6, characterized in that: The live bacteria concentration of the jelly-like bacillus in the microbial agent is 10 7 ~10 10 CFU / mL.

8. Use of the coal-based solid waste composite material according to any one of claims 1 to 7 in the remediation of heavy metal contaminated soil.

9. A soil remediation method, characterized in that: The following steps are involved: Mixing the coal-based solid waste composite material according to any one of claims 1 to 7 with uncontaminated soil to obtain a repair substrate; The remediation substrate is mixed with the heavy metal contaminated soil to be remediated to carry out soil remediation.

10. The soil remediation method according to claim 9, characterized in that: The weight ratio of the coal-based solid waste composite material to the non-polluted soil is 1:50 to 150; The weight ratio of the repair substrate to the heavy metal contaminated soil to be repaired is 1:10-50.

Images