Heavy metal pollution remediation material combining minerals and fungi and preparation and remediation methods

Abstract

The invention discloses a mineral and fungus combined heavy metal pollution remediation material and a preparation and remediation method thereof. The heavy metal pollution remediation material comprises the following components in parts by mass: 40 parts of clay minerals, 40 parts of phosphate minerals, 5-10 parts of fungi and the balance of an organic material matrix, wherein the clay mineral is zeolite, the phosphate mineral is apatite, and the fungus is one of penicillium fungus. The repairing material with high adsorption capacity is formed by utilizing the porous structure of minerals and combining the biological activity of fungi; the structure can effectively adsorb heavy metal ions in soil, and migration and diffusion of the heavy metal ions in the soil are reduced; experiments show that the content of heavy metal ions in soil can be effectively reduced. Based on more detailed and specific consideration and research, the invention further provides a preparation method of the heavy metal pollution remediation material and a soil remediation method, so that the optimal remediation effect is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil remediation, and in particular relates to a heavy metal pollution remediation material combining minerals and fungi and a preparation and remediation method thereof. Background Art

[0002] Heavy metals are not biodegradable, and the environmental pollution they cause is becoming increasingly serious, which has an adverse impact on the stability of the ecosystem and has threatened human health. This will reduce the species and richness and lead to ecosystem degradation. The treatment of heavy metal pollution mainly includes physical and chemical remediation methods and biological remediation methods. Among them, physical and chemical remediation methods such as chemical precipitation, ion exchange, reverse osmosis, extraction, and activated carbon adsorption have the disadvantages of high cost, high energy consumption, difficult operation, and easy secondary pollution. Therefore, it is recommended to adopt a biological remediation strategy. The main advantage of biological remediation is its high efficiency in reducing heavy metal ions, and it is considered to be an effective remediation method. Minerals have important application value in the remediation of heavy metal pollution. Mineral materials have strong surface activity and are easy to react with heavy metal ions. They usually have a large specific surface area and pore structure. These characteristics enable them to effectively adsorb and fix heavy metal ions. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a heavy metal pollution remediation material combining minerals and fungi and a preparation and remediation method, which is mainly aimed at improving the efficiency and safety of heavy metal pollution remediation, reducing secondary pollution, and taking into account the remediation cost and environmental impact. By combining the advantages of minerals and fungi, efficient and environmentally friendly remediation of heavy metal contaminated soil can be achieved.

[0004] According to the technical solution of the present invention, the present invention provides a heavy metal pollution remediation material combining minerals and fungi, including the following components in parts by mass: 40 parts of clay minerals, 40 parts of phosphate minerals, 5 to 10 parts of fungi, and the rest being an organic material matrix; wherein the clay mineral is zeolite, the phosphate mineral is apatite, and the fungus is a type of Penicillium fungus.

[0005] Furthermore, the particle size of the zeolite is less than 400 mesh and the specific surface area is greater than 280m 2 / g.

[0006] According to the technical solution of the present invention, the present invention also provides a method for preparing a heavy metal pollution repair material combining minerals and fungi, which is used to prepare the heavy metal pollution repair material combining minerals and fungi of the present invention, and comprises the following steps: Taking zeolite and apatite by weight, mixing and stirring evenly to prepare a mixed matrix; The fungus is inoculated into the mixed matrix according to the mass fraction, and solid fermentation is carried out to obtain the heavy metal pollution remediation material.

[0007] Furthermore, the particle size of the zeolite used is below 400 meshes; the treatment method of the zeolite is to first mix the zeolite with hydrochloric acid having a pH value of 3.8 to 4.0 at a solid-liquid ratio of 1:50 and shake for 24 hours, and then grind the zeolite to 400 meshes.

[0008] Furthermore, when zeolite and apatite are mixed, apatite is added to zeolite at a rate of 300 g / min to 500 g / min.

[0009] Furthermore, the temperature of solid fermentation is 30°C to 40°C, and the ventilation volume is 4m 3 / h~6m 3 / h, time is 2 to 3 days.

[0010] Furthermore, the total number of fungal spores after solid fermentation is not less than 109 / g.

[0011] According to the technical solution of the present invention, the present invention also provides a method for remediating heavy metal pollution combining minerals and fungi, which adopts the heavy metal pollution remediation material combining minerals and fungi described in the present invention, and includes the following steps: mixing the heavy metal pollution remediation material combining minerals and fungi with soil, and maintaining the soil moisture content at 50% to 80%, and the remediation period is 30 days to 90 days.

[0012] Compared with the prior art, the beneficial technical effects of the present invention are as follows: The heavy metal pollution remediation material combining minerals and fungi of the present invention utilizes the porous structure of minerals and combines the biological activity of fungi to form a remediation material with high adsorption capacity; this structure can effectively adsorb heavy metal ions in the soil and reduce their migration and diffusion in the soil; experiments show that it can effectively reduce the content of heavy metal ions in the soil. Based on more detailed and specific considerations and studies, the present invention further provides a preparation method of the heavy metal pollution remediation material and a method for soil remediation to achieve the best remediation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flow chart of a preparation method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention provides a heavy metal pollution remediation material combining minerals and fungi, as well as a preparation and remediation method, which is mainly aimed at improving the efficiency and safety of heavy metal pollution remediation, reducing secondary pollution, and taking into account the remediation cost and environmental impact. By combining the advantages of minerals and fungi, efficient and environmentally friendly remediation of heavy metal contaminated soil can be achieved.

[0015] A heavy metal pollution remediation material combining minerals and fungi according to an embodiment of the present invention comprises the following components by weight: 40 parts of clay minerals, 40 parts of phosphate minerals, 5 to 10 parts of fungi, and the rest being an organic material matrix (i.e., organic fertilizer that complies with the NY525-2021 standard). The component ratio in this scheme is a weight ratio according to the ratio of fungi to the nutrients required during the growth process.

[0016] Wherein, the clay mineral is zeolite.

[0017] Zeolite is a hydrous alkali metal or alkaline earth metal aluminum silicate mineral with high catalytic activity, high temperature resistance, acid resistance, and anti-poisoning properties. It also has a porous structure and a large specific surface area, which makes it have strong adsorption properties and ion exchange capacity. Its cation exchange capacity is about 10 times that of peat, making it a good adsorption material. Restoration principle: Zeolite can effectively adsorb heavy metal ions in soil and water, such as lead, cadmium, and mercury, through its surface negative charge and pore structure. In addition, zeolite can also adjust the pH value of the soil, further promoting the precipitation and fixation of heavy metals. Application advantages: Zeolite has abundant reserves, low cost, and good adsorption effect on a variety of heavy metal ions. It is an ideal heavy metal pollution restoration material.

[0018] Preferably, the zeolite has a particle size of less than 400 mesh and a specific surface area of ​​more than 280 m 2 / g; more specifically, hydrochloric acid with a pH value of 3.8 to 4.0 is first used to mix with zeolite at a solid-liquid ratio of 1:50 and shaken for 24 hours, and then the zeolite is ground into 400 meshes.

[0019] The phosphate mineral is apatite.

[0020] Apatite is a phosphate mineral whose main component is calcium phosphate. It is widely present in nature and has low cost. Apatite minerals have good biological activity and biocompatibility because the main component of vertebrate bones and teeth is hydroxyapatite. Although apatite itself is not directly used for the adsorption of heavy metals, as the main component of phosphate fertilizer, it can indirectly affect the migration and transformation of heavy metals by increasing the phosphorus content in the soil. Repair mechanism: Apatite reacts chemically with heavy metal ions in the soil to form insoluble heavy metal phosphate precipitates, thereby reducing the bioavailability and mobility of heavy metals.

[0021] The fungus is a kind of Penicillium fungus.

[0022] Penicillium generally plays the role of a dominant strain in the process of microbial cultivation and is basically not infected by other bacteria. Penicillium fungi have strong heavy metal tolerance and bioaccumulation ability, and can survive and reproduce in heavy metal polluted environments. Repair mechanism: Penicillium fungi transfer heavy metal ions from the soil to the fungus through cell wall adsorption, intracellular complexation and precipitation, thereby achieving heavy metal removal. In addition, fungi can also secrete metabolites such as organic acids, which further promote the dissolution and fixation of heavy metals. It can not only effectively remove heavy metal ions in the soil, but also has the advantages of being eco-friendly and low-cost.

[0023] In a specific embodiment, the heavy metal pollution remediation material includes the following components in parts by weight: 40 parts of zeolite, 40 parts of apatite, 5 parts of fungi, and the remainder (15 parts) is an organic material matrix.

[0024] See also Figure 1 Based on the above heavy metal pollution remediation material, the present invention further provides a preparation method, comprising the following steps: Taking zeolite and apatite by weight, mixing and stirring evenly to prepare a mixed matrix; The fungi are inoculated into the mixed matrix according to the mass proportion, and then solid fermentation is carried out to obtain the heavy metal pollution remediation material; wherein the organic material matrix is ​​added into the mixed matrix together with the fungi during the fungi inoculation.

[0025] Among them, when zeolite and apatite are mixed, apatite is added to zeolite at a rate of 300g / min to 500g / min. Experiments show that this input rate is moderate. If it is too low, it will lead to insufficient phosphorus required for microbial growth, and if it is too high, the excess calcium in the apatite will cause stress to the microorganisms.

[0026] Furthermore, in the above steps, the temperature of the solid fermentation is 30°C to 40°C, and the ventilation volume is 4m 3 / h~6m 3 / h, the time is 2 to 3 days; the experiment shows that this temperature is suitable for Penicillium fermentation. The Penicillium used is an aerobic bacteria. Ensuring appropriate ventilation can ensure aerobic respiration of the bacteria.

[0027] Furthermore, the fungus is inoculated into the mixed matrix for solid fermentation until the total number of fungal spores is not less than 109 / g; at this time, the fungus is in the logarithmic phase of the growth process, with the maximum growth rate, active enzyme system and vigorous metabolism.

[0028] The above-mentioned heavy metal pollution remediation material is used to remediate heavy metal contaminated soil. The remediation steps are: mixing the remediation material with soil and maintaining the soil moisture content at 50% to 80%. The remediation period is 30 to 90 days. Ensuring a certain moisture content is suitable for fungal growth and metabolism, and the appropriate remediation time allows the fungi to fully adapt to the environment of the contaminated soil and achieve the best remediation effect.

Claims

1. A heavy metal pollution remediation material combining minerals and fungi, characterized in that: The invention comprises the following components in parts by weight: 40 parts of clay mineral, 40 parts of phosphate mineral, 5 to 10 parts of fungi, and the rest being organic material matrix; wherein the clay mineral is zeolite, the phosphate mineral is apatite, and the fungi is one of the genus Penicillium.

2. The heavy metal pollution remediation material combining minerals and fungi according to claim 1, characterized in that: The particle size of zeolite is below 400 mesh and the specific surface area is greater than 280m 2 / g.

3. A method for preparing a heavy metal pollution remediation material combining minerals and fungi, characterized in that: The method for preparing the heavy metal pollution remediation material combining minerals and fungi according to claim 1 comprises the following steps: Taking zeolite and apatite in parts by mass, mixing and stirring evenly to prepare a mixed matrix; The fungus is inoculated into the mixed matrix according to the mass fraction, and solid fermentation is carried out to obtain the heavy metal pollution remediation material.

4. The method for preparing a heavy metal pollution repair material combining minerals and fungi according to claim 3, characterized in that: The particle size of the zeolite used is below 400 meshes; the treatment method of the zeolite is to first mix the zeolite with hydrochloric acid having a pH value of 3.8 to 4.0 at a solid-liquid ratio of 1:50 and shake for 24 hours, and then grind the zeolite to 400 meshes.

5. The method for preparing a heavy metal pollution repair material combining minerals and fungi according to claim 3, characterized in that: When zeolite and apatite are mixed, apatite is added to zeolite at a rate of 300 g / min to 500 g / min.

6. The method for preparing a heavy metal pollution repair material combining minerals and fungi according to claim 3, characterized in that: The temperature of solid fermentation is 30℃~40℃, and the ventilation volume is 4m 3 / h~6m 3 / h, time is 2 to 3 days.

7. The method for preparing a heavy metal pollution repair material combining minerals and fungi according to claim 6, characterized in that: The total number of fungal spores after solid fermentation is not less than 109 / g.

8. A method for remediating heavy metal pollution by combining minerals and fungi, characterized in that: It uses the heavy metal pollution repair material combining minerals and fungi according to claim 1, which includes the following steps: mixing the heavy metal pollution repair material combining minerals and fungi with soil, and maintaining the soil moisture content at 50% to 80%, and the repair period is 30 days to 90 days.

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