Heavy metal pollution repairing material combined with minerals and bacteria and preparation and repairing methods of heavy metal pollution repairing material

Abstract

The invention discloses a heavy metal pollution remediation material combining minerals and bacteria and a preparation and remediation method thereof. The heavy metal pollution remediation material comprises the following components in parts by mass: 50 parts of clay minerals, 30 parts of phosphate minerals, 10 parts of bacteria and the balance of organic fertilizer as a matrix, wherein the clay mineral is attapulgite, the phosphate mineral is apatite, and the bacteria are one of enterobacter. By combining the characteristics of minerals and bacteria, the remediation material has strong adsorption capacity and can effectively remove heavy metal ions in soil. Meanwhile, the enterobacter converts heavy metal ions into insoluble precipitates through a bioremediation mechanism of the enterobacter, such as adsorption, reduction, chelation and the like, so that subsequent treatment is facilitated. The metabolic activity of the enterobacter in the soil can promote the growth and activity of soil microorganisms, increase the content of beneficial elements in the soil, improve the soil structure and improve the soil quality.

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 bacteria and a preparation and remediation method thereof. Background Art

[0002] Heavy metal pollution has become a global environmental problem, and its sources are wide-ranging, including industrial emissions, sewage irrigation, and mineral mining. Heavy metal pollution has caused serious damage to soil, water bodies, and ecosystems, and may enter the human body through the food chain, posing a threat to human health. Therefore, it is crucial to find effective heavy metal pollution remediation technologies. The treatment of heavy metal pollution mainly includes physical and chemical remediation methods and bioremediation 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. Bioremediation is considered to be an effective remediation method due to its high efficiency in reducing heavy metal ions. The interaction between microorganisms and heavy metals is mainly focused on the removal of heavy metals, involving two processes: bioaccumulation and bioremediation. The remediation of soil heavy metal pollutants by bacteria is a high-efficiency, eco-friendly remediation and stabilization strategy. In addition to remediating heavy metals in soil, bacteria can also promote growth through higher nutrient utilization and supply of substances required by plants in heavy metal-contaminated soil, and have good application prospects. 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 bacteria and a preparation and remediation method to effectively solve the heavy metal pollution problem and improve soil quality; more specifically, to provide an efficient, environmentally friendly and economical remediation solution for the current problems of long heavy metal contaminated soil treatment cycle, high cost and possible secondary pollution.

[0004] According to the technical solution of the present invention, the present invention provides a heavy metal pollution remediation material combining minerals and bacteria, comprising the following components in parts by mass: 50 parts of clay minerals, 30 parts of phosphate minerals, 10 parts of bacteria, and the rest are organic fertilizers that meet the NY525-2021 standard as a matrix; wherein the clay mineral is attapulgite, the phosphate mineral is apatite, and the bacteria is a type of Enterobacter.

[0005] Furthermore, the attapulgite has a Mg content greater than 3%, a particle size less than 400 mesh, and a specific surface area greater than 150 m 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 bacteria, which is used to prepare the heavy metal pollution repair material combining minerals and bacteria of the present invention, and comprises the following steps: Taking attapulgite and apatite in parts by mass, mixing and stirring evenly to prepare a mixed matrix; Enterobacter is 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.

[0007] Furthermore, when attapulgite and apatite are mixed, apatite is added to the attapulgite at a rate of 300 g / min to 500 g / min.

[0008] Furthermore, the temperature of solid fermentation is 20℃~25℃, and the ventilation volume is 4m 3 / h~6m 3 / h, time is 2 to 3 days.

[0009] According to the technical solution of the present invention, the present invention also provides a method for repairing heavy metal pollution by combining minerals and bacteria, which adopts the heavy metal pollution repair material combining minerals and bacteria described in the present invention, and includes the following steps: mixing the heavy metal pollution repair material combining minerals and bacteria with soil, and maintaining the soil moisture content at 50% to 80%, and the repair period is 30 days to 90 days.

[0010] Compared with the prior art, the beneficial technical effects of the present invention are as follows: The present invention combines the characteristics of minerals and bacteria, and the repair material has a strong adsorption capacity and can effectively remove heavy metal ions in the soil. At the same time, Enterobacteriaceae converts heavy metal ions into insoluble precipitates through its biological repair mechanism, such as adsorption, reduction, chelation, etc., which is convenient for subsequent treatment. The metabolic activity of Enterobacteriaceae in the soil can promote the growth and activity of soil microorganisms, increase the content of beneficial elements in the soil, improve soil structure, and improve soil quality. While repairing heavy metal pollution, bacteria convert the insoluble phosphorus in the soil into effective phosphorus that can be absorbed by plants through their metabolic activities, such as phosphorus solubilization, and improve the fertility and ecological environment of the soil. The soil treated with the repair material of the present invention not only has a significantly reduced heavy metal content, but also improves soil fertility and plant growth conditions, providing a good soil environment for the growth of crops. The mineral materials and bacteria used in the present invention are both environmentally friendly materials and will not cause secondary pollution to the soil and groundwater. At the same time, the technology is simple and easy to operate, with moderate cost, which is conducive to large-scale promotion and application. Through experimental verification, the repair material of the present invention has a significant repair effect on heavy metal contaminated soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1is a flow chart of a preparation method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0012] The present invention provides a heavy metal pollution remediation material combining minerals and bacteria and a preparation and remediation method to effectively solve the heavy metal pollution problem and improve soil quality; more specifically, it provides an efficient, environmentally friendly and economical remediation solution to address the current problems of long heavy metal pollution soil treatment cycle, high cost and possible secondary pollution.

[0013] A heavy metal pollution remediation material combining minerals and bacteria according to an embodiment of the present invention comprises the following components by weight: 50 parts of clay minerals, 30 parts of phosphate minerals, 10 parts of bacteria, and the rest of organic fertilizers that meet the NY525-2021 standard as a matrix. The component ratio in this scheme is a weight ratio according to the ratio of bacteria to the nutrients required during the growth process.

[0014] Wherein, the clay mineral is attapulgite.

[0015] Attapulgite has a unique pore structure. At the same time, the aggregates composed of needle-shaped and rod-shaped crystal particles have interstitial pores of varying sizes. In terms of crystal chemical composition, Al may partially replace Si and coordinate Mg at the edge of the octahedron. 2+ The presence of Mg makes the attapulgite crystals replaceable for metal ions. Preferably, the attapulgite has a Mg content (converted into magnesium oxide) greater than 3%, a particle size less than 400 mesh, and a specific surface area greater than 150 m 2 / g.

[0016] The phosphate mineral is apatite.

[0017] Apatite minerals are widely present in nature and have low cost. Since the main component of vertebrate bones and teeth is hydroxyapatite, apatite minerals have good bioactivity and biocompatibility.

[0018] The bacterium is a kind of Enterobacter.

[0019] Enterobacteriaceae can exist stably in contaminated soil. Adding clay minerals and phosphate minerals while inoculating Enterobacteriaceae can significantly increase the types and numbers of soil microbial communities.

[0020] In a specific embodiment, the heavy metal pollution remediation material includes the following components in parts by weight: 50 parts of attapulgite, 30 parts of apatite, 10 parts of Enterobacteriaceae, and the remainder (10 parts) is an organic material matrix (i.e., organic fertilizer that meets the NY525-2021 standard).

[0021] Based on the above-mentioned heavy metal pollution remediation material, the present invention further provides a preparation method, comprising the following steps: Taking attapulgite and apatite in parts by mass, mixing and stirring evenly to prepare a mixed matrix; Enterobacteriaceae are inoculated into a mixed matrix by mass, and then solid fermentation is carried out to obtain a heavy metal pollution remediation material; wherein the organic material matrix is ​​added to the mixed matrix together with the Enterobacteriaceae when the Enterobacteriaceae are inoculated.

[0022] Among them, when attapulgite and apatite are mixed, apatite is added to the attapulgite 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.

[0023] Furthermore, in the above steps, the temperature of the solid fermentation is 20°C to 25°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 Enterobacter fermentation, the bacteria used are aerobic bacteria, and ensuring appropriate ventilation can ensure aerobic respiration of the bacteria.

[0024] The above-mentioned heavy metal pollution remediation material is used for the remediation of 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. A certain moisture content is guaranteed to be suitable for bacterial growth and metabolism. The appropriate remediation time allows bacteria 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 bacteria, characterized in that: The invention comprises the following components in parts by weight: 50 parts of clay mineral, 30 parts of phosphate mineral, 10 parts of bacteria, and the rest of organic fertilizer as a matrix; wherein the clay mineral is attapulgite, the phosphate mineral is apatite, and the bacteria is one of Enterobacter.

2. The heavy metal pollution remediation material combining minerals and bacteria according to claim 1, characterized in that: The Mg content of attapulgite is greater than 3%, the particle size is less than 400 mesh, and the specific surface area is greater than 150m 2 / g.

3. A method for preparing a heavy metal pollution remediation material combining minerals and bacteria, characterized in that: The method for preparing the heavy metal pollution remediation material combining minerals and bacteria according to claim 1 or 2 comprises the following steps: Taking attapulgite and apatite in parts by mass, mixing and stirring evenly to prepare a mixed matrix; Enterobacter is 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.

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

5. The method for preparing a heavy metal pollution repair material combining minerals and bacteria according to claim 3, characterized in that: The temperature of solid fermentation is 20℃~25℃, and the ventilation volume is 4m 3 / h~6m 3 / h, time is 2 to 3 days.

6. A method for remediating heavy metal pollution by combining minerals and bacteria, characterized in that: It uses the heavy metal pollution repair material combining minerals and bacteria according to claim 1, which includes the following steps: mixing the heavy metal pollution repair material combining minerals and bacteria 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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