Simple device for recovering heavy metals by using biological agent

Abstract

The invention relates to a simple device for recovering heavy metals by a biological agent. The simple device comprises three parts, namely an internal adsorbate or a soluble additive, an external filtering material and an adhesive. Wherein the external filtering material is divided into an upper part and a lower part, the upper part and the lower part of the external filtering material are adhered through an adhesive at the edge, and an internal closed space is filled with an internal adsorbate or a soluble additive. The device can achieve different application purposes by replacing an internal adsorbate or a soluble additive, can be used for adsorption and recovery of soil pollutants such as heavy metals when the adsorbate is filled, and can be regarded as a soil additive slow release device when the soluble additive is added. The whole device is easy to manufacture, low in cost, convenient to use, excellent in effect and capable of meeting the requirements of multiple soil related operations.

Description

Technical Field

[0001] The present invention relates to a simple device for recovering heavy metals with biological agents, and in particular to a simple device suitable for adding biochar materials loaded with microorganisms for recovering heavy metals in soil, and also suitable for adding soluble additives for releasing soil additives. Background Art

[0002] With the rapid development of agricultural modernization and industry in modern times, heavy metals in the soil have become important pollutants and ecological risk factors that cannot be ignored in agricultural production. Extremely low concentrations of heavy metals can cause poisoning symptoms in organisms, and heavy metals in the soil can be absorbed by plants and enriched along the food chain and food web, thereby expanding the scope of pollution. Unlike organic pollutants, heavy metal pollution is hidden, stubborn, transmissible and accumulative. Once pollutants enter the soil, except for the transformation between different forms, it is difficult to extract them by conventional methods and they cannot be degraded.

[0003] Common methods for treating heavy metal pollutants in soil are mainly chemical precipitation, physical adsorption, and hyperaccumulator plants and microbial remediation. Among them, the use of hyperaccumulator plants can effectively extract heavy metal elements from the soil, but its long recovery time and the accompanying occupation of land resources limit the actual application scenarios; microbial remediation has poor stability due to the complex soil environment, and the treatment effect is easily affected; and the most commonly used chemical precipitation and physical adsorption have the problem of easy remediation but difficult recovery due to the special physical and chemical properties of the soil. Therefore, the design of an adsorbent recovery device with low cost, convenient use, good adaptability, and wide application has important scientific significance and application prospects.

[0004] The existence states of heavy metals in soil can be mainly divided into soluble state, organic binding state, exchange state, precipitation state and residual state. Among them, the soluble state and exchange state with strong migration ability are the main states of heavy metal pollution. Soil colloids have poor adsorption capacity for them and are easily migrated in the soil with environmental changes such as water flow. Therefore, a recyclable device can be designed based on this characteristic of heavy metal pollution, so that it is possible to fundamentally eliminate soil heavy metal pollution after the adsorbent completes adsorption. Summary of the invention

[0005] In view of this, in order to solve the problems existing in the prior art, the present invention provides a simple device for recovering heavy metals with biological bacteria agents through improvement.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A simple device for recovering heavy metals with a biological agent comprises an internal adsorbent or a soluble additive, an external filter material and an adhesive; wherein the external filter material is divided into an upper and a lower part, the edges of the external filter material of the upper and lower parts are bonded by an adhesive, and the internal closed space is filled with the internal adsorbent or the soluble additive.

[0008] It is worth noting that the simple device for recovering heavy metals with biological agents disclosed in the present invention should be buried at a depth of 10-20 cm in the soil, and should be buried in the soil for more than 30 days before recovery, so as to ensure the enrichment effect of the internal adsorbent on the heavy metals in the rhizosphere soil.

[0009] Optionally, the internal adsorbent is prepared using biochar with a particle size of 1-3 mm and other porous adsorption materials with stable properties as templates to load functional microorganisms; the biochar should be prepared using straw-like materials as raw materials, and the rich functional groups on its surface are conducive to the stable attachment of bacteria and fungi to the surface of the adsorbent, thereby ensuring the use effect of the device, ensuring its ability to adhere to bacteria and fungi, and achieving the application effect of enriching rhizosphere heavy metals.

[0010] Furthermore, the porous adsorption material includes metal organic framework compounds and porous ceramics.

[0011] As a preferred solution, agricultural waste straw is used as the raw material for biochar preparation. The raw material is easy to obtain, the process is simple, the use is clean, and the cost is low.

[0012] It should be noted that the internal adsorbent should be relatively stable in nature. When used to load functional adsorption fungi to recover soil heavy metals, the specific surface area of ​​the internal adsorbent should be greater than 150 m 2 / g, the particle size should be 1-3mm to ensure the adhesion ability and pore filling degree of bacterial cells and fungal spores, and the particle size reduction should be less than 5% to ensure good mechanical strength and prevent leakage. The above parameters ensure that the internal adsorbent will not be released into the soil through the external filter material during the process of absorbing heavy metals in the soil, thereby achieving the purpose of enriching heavy metals in the soil.

[0013] Optionally, the soluble additives include hole-applied biological pesticides, hole-applied chemical pesticides, soil buffers, soluble soil remediation agents, and granular fertilizers, and the dosage form uses columnar or spherical granules to avoid using powders to prevent the slow-release effect of the soluble additives from being affected.

[0014] Furthermore, the internal adsorbent or soluble additive is added into the adhesive-free space in the middle of the upper and lower layers of external filter materials.

[0015] Optionally, the external filter material is made of nylon gauze or stainless steel gauze to prevent the external filter material from being broken due to the action of microorganisms or mechanical damage caused by farming activities in the soil environment.

[0016] Furthermore, when the device is used for heavy metal adsorption, an external filter material with a pore size range of 30-100 μm should be selected, and when it is used for sustained release of internal soluble additives, an external filter material with a pore size range of 50-150 μm should be selected.

[0017] Furthermore, the shapes of the external filter materials of the upper and lower parts are determined according to actual needs, and a circular filter material with a diameter of 5-10 cm can be used.

[0018] It should be noted that the external filter material should be adjusted according to the specific functions to be carried out. According to experimental results, when the device is used for heavy metal adsorption, filter materials with a pore size range of 30-100μm should be selected to ensure its ability to bind internal bacteria and recover heavy metal elements; when used for sustained release of internal soluble additives, filter materials with a pore size range of 50-150μm should be selected to reasonably control the amount of water contact and the dissolution rate of the internal soluble additives to achieve the purpose of sustained release. The external filter material should be non-toxic and harmless, have a certain mechanical strength and flexibility, and be resistant to weak acid and alkali corrosion to a certain extent.

[0019] Optionally, the type of adhesive for the external filter material depends on the use environment, and EVA hot melt adhesive can be used to bond the upper and lower parts of the external filter material, thereby achieving the purpose of convenient processing, mass production and recycling.

[0020] Furthermore, the bonding sites of the adhesive to the external filter material are the edges of the upper and lower layers of the external filter material.

[0021] After optimizing the above scheme, the following is the subsidiary technical scheme of the present invention:

[0022] The shape of the external filter material can be made of two layers of round gauze with a diameter of 5-10cm. After adding internal adsorbents or soluble additives in the middle, the edges of the upper and lower layers of filter material are bonded with EVA hot melt adhesive to form a closed recyclable simple device. The bonding thickness is 5mm-20mm depending on different functions.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The simple device disclosed in the present invention can achieve different application purposes by replacing the internal adsorbent or soluble additive. When filled with adsorbent, it can be used for adsorption and recovery of soil pollutants such as heavy metals, and when added with soluble additives, it can be regarded as a slow-release device for soil additives. The whole device is simple to make, low in cost, easy to use, and has excellent effects, and can meet the needs of multiple soil-related operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 The diagram is a schematic diagram of the decomposed structure of a simple device for recovering heavy metals using a biological agent disclosed in the present invention.

[0027] Figure 2 It is a rendering of the device after successful recycling according to the embodiment of the present invention.

[0028] In the figure:

[0029] 1-lower layer external filter material; 2-internal adsorbent or soluble additive;

[0030] 3-upper outer filter material; 4-adhesive. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0033] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0034] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0035] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0036] The invention discloses a simple device for recovering heavy metals using a biological bacterial agent.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "bonding", "adsorption" and the like should be understood in a broad sense, for example, it can be directly connected, or bonded by EVA hot melt adhesive, or by adding other substances to assist the bonding of external filter materials; it can be a physical adsorption or a chemical adsorption process. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Figure 1 It is a schematic diagram of the decomposed structure of a simple device for recovering heavy metals using biological bacteria agents according to the present invention; Figure 2 It is a rendering of the device after successful recycling of the present invention.

[0039] The implementation of the present invention is to apply 4 adhesives along the edge of 1 lower layer external filter material, fill 3 internal adsorbents or soluble additives into the middle of 1 lower layer external filter material without 4 adhesives, and place 2 upper layer external filter materials directly opposite to 1 lower layer external filter material to complete the sealing of 3 internal adsorbents or soluble additives through 4 adhesives.

[0040] On the basis of the above embodiment, the device is placed into the tillage layer soil with a depth of 10-20 cm when turning the soil, applying base fertilizer or sowing.

[0041] Based on the above embodiment, the device can be recycled when the crop is harvested or after a period of time. The specific effect after recycling is shown in Figure 2 The rendering of the device after recovery, after elution treatment, the heavy metals adsorbed by the internal adsorbent or soluble additives are recovered or the soluble additives are refilled.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

[0043] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following preferred test examples are used to further illustrate the technical features disclosed in the present invention, but they should not be understood as limiting the present invention. Other improvements made by those skilled in the art based on the above invention content without creative work are also considered to fall within the scope of protection of the present invention.

[0044] Based on the features described in each part, the present invention optimizes the technical solution by controlling the following variables through orthogonal experiments:

[0045] 1. The diameter of the external filter material is 2cm, 5cm, 8cm, 10cm, 15cm, the material is nylon, polyester, stainless steel, iron yarn, and the pore size is 25μm, 45μm, 105μm, 150μm, 200μm, 250μm, 300μm;

[0046] 2. The internal adsorbents include corn straw biochar loaded with Aspergillus niger, tobacco straw biochar loaded with Aspergillus niger, walnut shell biochar loaded with Aspergillus niger, corn straw biochar loaded with Beauveria bassiana, corn straw biochar loaded with Aspergillus niger and Beauveria bassiana, columnar granular organic fertilizer, and imidacloprid powder;

[0047] 3. The adhesive can be EVA hot melt adhesive, silicone sealant, or polyurethane adhesive, and the bonding thickness can be 2mm, 5mm, 10mm, 15mm, 20mm, 25mm, or 30mm. Furthermore, the shape of the external filter material can use two layers of circular gauze with a diameter of 5-10cm. After adding internal adsorbents or soluble additives in the middle, the edges of the upper and lower layers of filter materials are bonded by EVA hot melt adhesive to form a closed, recyclable simple device. The bonding thickness is 5mm-20mm depending on different functions.

[0048] The experiment selects the technical solutions by optimizing the above technical parameters. The evaluation of the optimal solutions is mainly based on the following indicators:

[0049] 1. The integrity of the external filter material, the degree of pore blockage and the water absorption capacity;

[0050] 2. The heavy metal adsorption capacity of internal adsorbents under the heavy metal adsorption function, the bacterial enrichment capacity and the heavy metal recovery amount, the slow release dissolution rate of soluble additives under the slow release function, the functionality and the residual time in the soil periphery space;

[0051] 3. The bonding effect of the adhesive, the bonding stability in the soil environment, and the decomposition rate.

[0052] It should be noted that the effective residual amounts of the contents of corn straw biochar loaded with Aspergillus niger and corn straw biochar loaded with Beauveria bassiana in the experimental preferred result table are determined by the number of effective live bacteria, and the effective residual amounts of the contents of columnar granular organic fertilizer and imidacloprid powder are determined by the residual dry matter mass, and the determination time is 7 days after the release.

[0053] Table 1 Effective residual rate of contents at different diameters when nylon is used as the external filter material, the bonding thickness is 10 mm, and the pore size is 105 μm

[0054]

[0055] Table 2 Effective residual rate of contents at different pore sizes when nylon is used as the external filter material, the bonding thickness is 10 mm, and the diameter is 8 μm

[0056]

[0057] Table 3 Effective residual rate of contents at different bonding thicknesses when nylon, 8 μm diameter, and 105 μm pore size are used as the external filter material

[0058]

[0059] The strength and deformation resistance of nylon mesh or stainless steel mesh used as the external filter material are significantly higher than other experimental materials. From the optimization results, it can be seen that the diameter of the device should not be too large, which will cause the contents to be easily affected by external deformation during the use of the device. According to the different uses of the device, the corresponding pore size should be changed. Among them, the pore size of 45-105μm can fully meet the use effects under different purposes.

[0060] Furthermore, soluble additives should avoid using powders, as external filter materials are unlikely to effectively hinder the dissolution of soluble powders, causing the soluble additives to dissolve too quickly and lose their sustained-release function.

[0061] Furthermore, the adhesive may be any of a variety of non-toxic adhesives, but care should be taken that the adhesive thickness is not too high, which would affect the effectiveness of the contents and reduce the mechanical strength of the device.

[0062] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simple device for recovering heavy metals using biological agents, characterized in that: include: internal adsorbent or soluble additive, external filter material and adhesive; wherein, The external filter material is divided into two parts, an upper part and an lower part. The edges of the external filter materials of the upper and lower parts are bonded by an adhesive, and the internal closed space is filled with internal adsorbent or soluble additives.

2. The simple device for recovering heavy metals with biological agents according to claim 1 is characterized in that: The internal adsorbent is prepared by using biochar with a particle size of 1-3 mm and other porous adsorption materials with stable properties as templates to load functional microorganisms; The biochar can be prepared using straw materials as raw materials, and the porous adsorption materials include metal organic framework compounds and porous ceramics.

3. The simple device for recovering heavy metals with biological agents according to claim 1 is characterized in that: The soluble additives include hole-applied biological pesticides, hole-applied chemical pesticides, soil buffers, soluble soil repair agents and granular fertilizers.

4. The simple device for recovering heavy metals with biological agents according to claim 1 is characterized in that: The adding position of the internal adsorbent or soluble additive is in the adhesive-free space in the middle of the upper and lower layers of external filter materials.

5. The simple device for recovering heavy metals with biological agents according to claim 1 is characterized in that: The external filter material is selected from nylon gauze or stainless steel gauze.

6. The simple device for recovering heavy metals using biological agents according to claim 1 or 5, characterized in that: When the device is used for heavy metal adsorption, an external filter material with a pore size range of 30-100 μm should be selected. When the device is used for sustained release of internal soluble additives, an external filter material with a pore size range of 50-150 μm should be selected.

7. The simple device for recovering heavy metals with biological agents according to claim 1 is characterized in that: The shapes of the external filter materials of the upper and lower parts are determined according to actual needs, and a circular filter material with a diameter of 5-10 cm can be used.

8. The simple device for recovering heavy metals with biological agents according to claim 1, characterized in that: The type of adhesive for the external filter material depends on the use environment, and EVA hot melt adhesive can be used.

9. The simple device for recovering heavy metals with biological agents according to claim 1, characterized in that: The bonding position of the adhesive to the external filter material is the edge of the upper and lower layers of the external filter material, and the bonding thickness is 5mm-20mm.

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