A carbon intergradient culture device for heavy metal contaminated soil remediation process and application

Abstract

The application relates to the technical field of soil sampling process analysis, in particular to a carbon interface gradient culture device for heavy metal contaminated soil repair processes and application.The carbon interface gradient culture device comprises a cylindrical culture container, a separation material layer, a dialysis bag and a multilayer separation mesh bag, the dialysis bag is arranged at the center of the cylindrical culture container, the multilayer separation mesh bag is arranged around the dialysis bag, and different area size carbon interface micro-domain gradient zones are formed between adjacent two separation mesh bags to accommodate heavy metal contaminated soil; the dialysis bag is used for accommodating liquid biochar-based materials to form a heavy metal contaminated soil repair area; the carbon interface gradient culture device can realize partition culture of different carbon interface gradients, effective adsorption of heavy metal components and accurate determination of CO2 emission gas in the culture stage, so that quantitative analysis of carbon emission of the carbon interface gradient of heavy metal contaminated soil in the heavy metal pollutant passivation repair process of soil can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil sampling process analysis, in particular to a carbon interfacial gradient culture device for heavy metal contaminated soil remediation process and application. BACKGROUND

[0002] With the rapid development of economic society, the problem of soil heavy metal pollution is becoming more and more serious. Soil heavy metal pollutants refer to the pollutants formed by heavy metals entering the soil through atmospheric deposition or water hard deposition. They are difficult to degrade by chemical and biological methods, and are easily enriched in organisms through the food chain, which will pose a great harm to the ecological environment and human health. Due to the characteristics of long residual period, irreversibility, easy migration, high toxicity, high concealment, complex chemical properties, and easy entry into the food chain to harm human health and ecological system safety, measures such as soil heavy metal investigation and evaluation, remediation and ecological control of soil heavy metal pollutants have been highly concerned by the society.

[0003] Soil carbon pool refers to the carbon storage in soil, which is crucial for maintaining the ecological function and quality of soil. Increasing soil carbon pool can help improve soil texture and structure, increase soil fertility and water retention capacity, thereby facilitating the mitigation of heavy metal migration and bioavailability in soil. Current studies have shown that soil with high organic matter content has better ability to adsorb and stabilize heavy metals, which can reduce the impact of heavy metals on the environment and organisms. However, when the soil carbon pool is damaged or reduced, such as soil degradation and degradation caused by excessive tillage and large-scale deforestation, the carrying capacity of soil to heavy metal pollutants may be weakened, which not only accelerates the migration of heavy metal pollutants but also reduces soil biodiversity, thereby increasing the risk of soil heavy metal pollution. Therefore, through reasonable soil management and protection measures, such as increasing organic matter content, improving soil structure, reducing the use of fertilizers and pesticides, etc., it is helpful to maintain the stability of soil carbon pool, thereby reducing the risk of soil heavy metal pollution and maintaining soil health and ecological balance.

[0004] Although the current treatment methods for heavy metal contaminated soil are becoming more and more perfect, there is a lack of relevant experimental devices for the quantitative research of soil carbon interfacial gradient in the process of soil heavy metal pollutant passivation remediation and the carbon emission caused by this process. It is difficult to effectively adsorb heavy metal components in heavy metal contaminated soil in the process of heavy metal contaminated soil passivation remediation, thereby making it difficult to accurately analyze the effect of soil carbon interfacial gradient. SUMMARY

[0005] The application provides a carbon interface gradient culture device for heavy metal contaminated soil remediation process and an application thereof, to solve the technical problems of lacking of an experimental device for effectively adsorbing heavy metal components in heavy metal contaminated soil in the heavy metal contaminated soil passivation remediation process and being difficult to accurately analyze the effect of the soil carbon interface gradient in the prior art.

[0006] In a first aspect, the application provides a carbon interface gradient culture device for heavy metal contaminated soil remediation process, which comprises:

[0007] a cylindrical culture container;

[0008] a separation material layer, which comprises a dialysis bag and a plurality of separation mesh bags, the dialysis bag is arranged at the center of the cylindrical culture container, the plurality of separation mesh bags are arranged around the dialysis bag, and different area size carbon interface micro-domain gradient zones are formed between adjacent two separation mesh bags to accommodate heavy metal contaminated soil; the dialysis bag is used to accommodate liquid biochar-based material to form a heavy metal contaminated soil remediation area.

[0009] Optionally, the pore size of the separation mesh bag is ≤500 mesh.

[0010] Optionally, the molecular weight cut-off of the dialysis bag is 10kDa-15kDa.

[0011] Optionally, the height ratio of the carbon interface micro-domain gradient zone to the separation material layer is ≤0.8.

[0012] Optionally, the spacing between adjacent two carbon interface micro-domain gradient zones is 1cm-3cm.

[0013] Optionally, the liquid biochar-based material comprises a water solution of straw biochar material.

[0014] In a second aspect, the application provides an application of the carbon interface gradient culture device for heavy metal contaminated soil remediation process, which comprises using the carbon interface gradient culture device in the first aspect for quantitative analysis of carbon emission determination.

[0015] Optionally, the quantitative analysis of carbon emission determination comprises the following steps:

[0016] sampling the heavy metal soil in different carbon interface micro-domain gradient zones in the carbon interface gradient culture device to obtain a to-be-tested soil sample;

[0017] determining the soil heavy metal concentration of the to-be-tested soil sample to obtain heavy metal concentration data;

[0018] determining the spatial micro-domain variation of CO2 emission of the to-be-tested soil sample to obtain CO2 emission data;

[0019] According to the heavy metal concentration data and the CO2 emission data, quantitative analysis of carbon emission determination is performed on the to-be-tested soil sample.

[0020] Optionally, the determination of the CO2 emission space micro-domain change of the to-be-tested soil sample to obtain the CO2 emission data comprises the following steps:

[0021] The to-be-tested soil sample is subjected to ex-situ culture, sampling container cleaning and sample high-concentration collection to obtain CO2 emission gas.

[0022] The CO2 emission gas is subjected to gas chromatography determination to obtain the CO2 emission data.

[0023] Optionally, the determination of the soil heavy metal concentration comprises determining the soil heavy metal concentration by using an inductively coupled plasma mass spectrometry method.

[0024] Compared with the prior art, the above technical solution provided by the embodiments of the present application has the following advantages:

[0025] The carbon interfacial gradient culture device for the heavy metal contaminated soil remediation process provided by the embodiments of the present application can selectively culture the heavy metal contaminated soil by setting the separation material layer in the cylindrical culture container, and the separation material layer can include a dialysis bag and a multi-layer separation mesh bag. The different heavy metal contaminated soils can be physically blocked by the separation mesh bag to avoid mutual influence between the heavy metal contaminated soils. The liquid biochar-based material contained in the dialysis bag can form a stable form by blocking the flow and diffusion of the liquid biochar-based material through the dialysis bag. The liquid biochar-based material in the dialysis bag can exchange gas with the carbon interfacial gradient zone formed between the separation mesh bag and the dialysis bag through the pores of the dialysis bag and the separation mesh bag, and a heavy metal contaminated soil remediation area can be formed to adsorb the heavy metals in the carbon interfacial gradient zone. Thus, the liquid biochar-based material can effectively adsorb the heavy metal components in the heavy metal contaminated soil, and reduce the toxic effects of the heavy metal components on the microorganisms in the heavy metal soil. In the passivation and remediation process of the heavy metal contaminated soil, the carbon sequestration capacity of the heavy metal contaminated soil can be improved, and the accuracy of the determination of the CO2 emission gas in the culture process of the soil heavy metal contamination passivation and remediation of the culture device can be improved. The carbon interfacial gradient culture device can not only realize the zonal culture of different carbon interfacial gradients and the passivation and remediation of the heavy metal contaminated soil in different carbon interfacial gradients, but also realize the accurate determination of the CO2 emission gas in the culture stage. Thus, the quantitative analysis of the carbon emission of the carbon interfacial gradient of the heavy metal contaminated soil in the soil heavy metal contamination passivation and remediation process can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate preferred embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the field, based on the drawings, other drawings can also be obtained without creative labor.

[0028] Figure 1 The structure schematic diagram of the quantitative analysis system for carbon emission measurement provided by the embodiments of the present application is shown in the figure.

[0029] Figure 2 The flowchart of the quantitative analysis method for carbon emission measurement provided by the embodiments of the present application is shown in the figure.

[0030] Figure 3 The detailed flowchart of the quantitative analysis method for carbon emission measurement provided by the embodiments of the present application is shown in the figure.

[0031] Figure 4 The comparative schematic diagram of the heavy metal component adsorption amount of the heavy metal contaminated soil in the carbon intermicrodomain gradient II in the 7-day culture experiment provided by the embodiments and the comparative examples of the present application is shown in the figure.

[0032] Figure 5 The comparative schematic diagram of the CO2 emission amount of the carbon intermicrodomain gradient II in the 7-day culture experiment provided by the embodiments and the comparative examples of the present application is shown in the figure.

[0033] In the figure, 1 is a column-shaped culture container, 2 is a separation material layer, 3 is a separation net bag, 4 is a dialysis bag, 5 is a carbon intermicrodomain gradient area, 6 is a heavy metal contaminated soil remediation area, 7 is a balance, 8 is a culture bottle, 9 is a constant temperature incubator, 10 is a needle cylinder, 11 is a headspace bottle, and 12 is a gas chromatograph. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] Unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment, etc. used in the present application can be purchased from the market or can be prepared by the existing methods.

[0036] Figure 1 An exemplary structural diagram of a carbon interface gradient culture device for a heavy metal contaminated soil remediation process provided by embodiments of the present application is shown;

[0037] As shown in Figure 1 The present application provides a carbon interface gradient culture device for heavy metal contaminated soil, which comprises:

[0038] a cylindrical culture container 1;

[0039] a layer of separation material 2, which comprises a dialysis bag 4 and a plurality of layers of separation mesh bags 3, the dialysis bag 4 is arranged at the center of the cylindrical culture container 1, and a plurality of layers of the separation mesh bags 3 are arranged around the dialysis bag 4, and the adjacent two separation mesh bags 3 form carbon interface micro-domain gradient zones 5 of different sizes to accommodate heavy metal contaminated soil; the dialysis bag 4 is used to accommodate liquid biochar-based materials to form a heavy metal contaminated soil remediation area 6.

[0040] It should be noted that the dialysis bag 4 can be a dialysis bag with a molecular weight cut-off of 14 kDa and a diameter of 70 mm when dry.

[0041] It should be noted that the upper end of the dialysis bag 4 can be open to facilitate the replacement or detection of liquid biochar-based materials.

[0042] It should be noted that the separation mesh bag 3 can be a nylon mesh bag.

[0043] It should be noted that the bottom surface of the cylindrical culture container 1 can be circular or quadrilateral; the outer shell material of the cylindrical culture container 1 can be a sterile transparent material, which can be an acrylic plate.

[0044] It should be noted that the bottom of the cylindrical culture container 1 can be provided with a plurality of small holes, and at least one small hole is arranged directly below the dialysis bag 4.

[0045] In some optional embodiments, the pore size of the separation mesh bag 3 is ≤ 500 mesh; in these embodiments, the pore size of the separation mesh bag 3 can be ≤ 500 mesh, which can facilitate the gas exchange between the heavy metal contaminated soil in the different interfacial micro-domain gradient zones 5 and the liquid biochar-based material in the dialysis bag 4 while the adsorption of the heavy metal components in the heavy metal contaminated soil by the liquid biochar-based material is completed, and the passivation and repair of the heavy metal contaminated soil can be achieved through the heavy metal soil repair area 6, so as to avoid the toxic effect of the heavy metal components on the microorganisms in the heavy metal contaminated soil in the interfacial micro-domain gradient zone 5 during the passivation and repair of the heavy metal contaminated soil, thereby improving the carbon fixation capacity of the heavy metal contaminated soil during the passivation and repair of the heavy metal contaminated soil, and further improving the accuracy of the subsequent quantitative analysis of the carbon emission in the heavy metal contaminated soil in the interfacial micro-domain gradient zone 5.

[0046] In some optional embodiments, the molecular weight cut-off of the dialysis bag 4 is 10 kDa-15 kDa; in these embodiments, the molecular weight cut-off of the dialysis bag 4 can be 10 kDa-15 kDa, which can facilitate the liquid biochar-based material to flow only in the dialysis bag 4, and further facilitate the liquid biochar-based material to effectively absorb the heavy metal components of the heavy metal contaminated soil in the different interfacial micro-domain gradient zones 5, so as to avoid the toxic effect of the heavy metal components on the microorganisms in the heavy metal contaminated soil in the interfacial micro-domain gradient zone 5, thereby improving the carbon fixation capacity of the heavy metal contaminated soil during the passivation and repair of the heavy metal contaminated soil.

[0047] The molecular weight cut-off of the dialysis bag 4 can be 10 kDa, 11 kDa, 12 kDa, 13 kDa, 14 kDa or 15 kDa.

[0048] In some optional embodiments, the height ratio of the interfacial micro-domain gradient zone 5 to the separation material layer 2 is ≤ 0.8; in these embodiments, the height ratio of the interfacial micro-domain gradient zone 5 to the separation material layer 2 can be ≤ 0.8, which can avoid the excessive heavy metal contaminated soil in the interfacial micro-domain gradient zone 5 from affecting the adsorption of the heavy metal components in the heavy metal contaminated soil by the heavy metal contaminated soil repair area 6, and reduce the toxic effect of the heavy metal components on the microorganisms in the heavy metal soil, thereby improving the carbon fixation capacity of the heavy metal contaminated soil during the passivation and repair of the heavy metal contaminated soil, and further improving the accuracy of the measurement of the CO2 emission gas during the passivation and repair of the heavy metal contaminated soil.

[0049] In some optional embodiments, the distance between two adjacent interfacial micro-domain gradient zones 5 is 1 cm-3 cm; in these embodiments, the distance between two adjacent interfacial micro-domain gradient zones 5 can be 1 cm-3 cm, which can facilitate the interfacial micro-domain gradient zone 5 to accommodate a sufficient volume of heavy metal contaminated soil.

[0050] The distance between the two adjacent carbon interfacial micro-domain gradient zones 5 can be 1 cm, 1.5 cm, 2.0 cm, 2.5 cm, or 3.0 cm.

[0051] In some alternative embodiments, the liquid biochar-based material comprises an aqueous solution of the straw biochar material; in these embodiments, the liquid biochar-based material can comprise an aqueous solution of the straw biochar material, which can facilitate the liquid biochar-based material to sufficiently absorb the heavy metal components of the heavy metal contaminated soil within the carbon interfacial micro-domain gradient zone 5, mitigate the toxic effects of the heavy metal components on the microorganisms in the heavy metal soil, and thus improve the carbon sequestration capacity of the heavy metal contaminated soil in the process of passivation remediation of the heavy metal contaminated soil.

[0052] It should be noted that the preparation process of the liquid biochar-based material comprises:

[0053] The straw biochar material is soaked in deionized water at a mass-volume ratio of 1:10, and is subjected to constant temperature oscillation at 120 rpm for 2 h, followed by filtration and washing, and this operation is repeated until the content of dissolved organic carbon (DOC) in the filtrate is less than 10 mg / L, a total of 6 times of washing, and the leaching liquor collected in the first 5 times is the liquid biochar-based material.

[0054] Based on a general inventive concept, the embodiments of the present application provide an application of a carbon interfacial gradient culture device in a heavy metal contaminated soil remediation process, which comprises using the carbon interfacial gradient culture device in quantitative analysis of carbon emission determination.

[0055] The application is realized based on the carbon interfacial gradient culture device described above, and the specific structure of the carbon interfacial gradient culture device can refer to the above embodiments. Since the application adopts part or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0056] Figure 2 An example of the quantitative analysis method of carbon emission determination provided by the embodiments of the present application is shown in the flowchart;

[0057] Figure 1 An example of the quantitative analysis system structure of carbon emission determination provided by the embodiments of the present application is shown in the structural diagram;

[0058] As Figure 2 and Figure 1 shown, in some alternative embodiments, the quantitative analysis of carbon emission determination comprises the steps of:

[0059] S1. Sampling the heavy metal soil in different carbon interfacial micro-domain gradient zones in the carbon interfacial gradient culture device to obtain a to-be-tested soil sample;

[0060] S2. determining the concentration of heavy metals in the soil sample to be tested to obtain heavy metal concentration data;

[0061] S3. determining the spatial micro-domain variation of CO2 emission of the soil sample to be tested to obtain CO2 emission data;

[0062] S4. quantitatively analyzing the carbon emission determination of the soil sample to be tested according to the heavy metal concentration data and the CO2 emission data; in these embodiments, the quantitative analysis of carbon emission determination can include soil heavy metal sampling, determination of soil heavy metal concentration, and determination of spatial micro-domain variation of CO2 emission, and during the passivation and repair process of soil heavy metal pollution, the CO2 emission and soil heavy metal concentration of the heavy metal contaminated soil in the carbon interfacial gradient cultivation device can be accurately determined, so that the quantitative analysis of carbon emission of the heavy metal contaminated soil can be realized during the passivation process of the heavy metal pollutant.

[0063] It should be noted that the soil sample to be tested can also be measured by the cutting ring method to determine the bulk density of the soil sample to be tested before the determination of the concentration of heavy metals in the soil and the determination of the spatial micro-domain variation of CO2 emission.

[0064] Figure 3 An exemplary detailed flowchart of the quantitative analysis method of carbon emission determination provided by the embodiments of the present application is shown;

[0065] As shown in Figure 3 in some optional embodiments, the determination of the spatial micro-domain variation of CO2 emission of the soil sample to be tested to obtain CO2 emission data includes the steps of:

[0066] S301. ex situ culture of the soil sample to be tested, cleaning of the sampling container, and high-concentration sampling of the sample to obtain CO2 emission gas;

[0067] S302. determining the CO2 emission gas by gas chromatography to obtain CO2 emission data; in these embodiments, the determination of the spatial micro-domain variation of CO2 emission can include ex situ culture, cleaning of the sampling container, high-concentration sampling of the sample, and determination by gas chromatography, and the CO2 emission data in the spatial micro-domain variation of CO2 emission can be accurately determined by gas chromatography.

[0068] In some optional embodiments, the determination of the concentration of heavy metals in the soil includes determining the concentration of heavy metals in the soil by inductively coupled plasma mass spectrometry; in these embodiments, the determination of the concentration of heavy metals in the soil can be performed by inductively coupled plasma mass spectrometry, so that the concentration of heavy metals in the heavy metal contaminated soil can be accurately determined during the passivation process of the heavy metal pollutant.

[0069] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0070] Example 1

[0071] like Figure 1 As shown, a carbon gradient culture device for heavy metal contaminated soil remediation includes:

[0072] A columnar culture container 1 has an inner height of 10cm, an inner diameter of 20cm, and a thickness of 3mm. The four sides of the columnar culture container 1 are made of transparent acrylic sterile plates.

[0073] The separating material layer 2 includes a dialysis bag 4 and a multi-layer separating mesh bag 3. The dialysis bag 4 is located at the center of the columnar culture container 1, and the multi-layer separating mesh bag 3 is arranged around the dialysis bag 4. Adjacent separating mesh bags 3 form carbon-internal micro-gradient zones 5 of different sizes to accommodate heavy metal contaminated soil. According to the distance between the carbon-internal micro-gradient zone 5 and the dialysis bag 4, the columnar culture container 1 can be divided into I: φ4cm~6cm, II: φ6cm~8cm, III: φ8cm~10cm, IV: φ10cm~13cm, V: φ13cm~16cm and VI: φ16cm~19cm.

[0074] Dialysis bag 4 is used to contain liquid biochar-based material to form a remediation zone 6 for heavy metal contaminated soil.

[0075] The mesh size of the separator bag 3 is 500 mesh.

[0076] The molecular weight cutoff of dialysis bag 4 is 14 kDa.

[0077] The height of the carbon interfacial micro-gradient region 5 is 8 cm (i.e., the height ratio of the carbon interfacial micro-gradient region 5 to the height of the separating material layer 2 is 0.8).

[0078] The distance between two adjacent carbon micro-domain gradient regions 5 is 2 cm.

[0079] Example 2

[0080] Based on the carbon-interstitial gradient culture device designed in Example 1, further operations were carried out:

[0081] An application of a carbon gradient culture device in the remediation process of heavy metal contaminated soil, including the use of the carbon gradient culture device in the quantitative analysis of carbon emission determination.

[0082] As shown in Figure 2 and Figure 3 The quantitative analysis of carbon emission determination includes the following steps:

[0083] S1. Sampling the heavy metal soil in different carbon interface micro-domain gradient zones in the carbon interface gradient culture device to obtain the soil sample to be tested; the sampling process includes:

[0084] Randomly sampling at least 5 times in the same carbon interface micro-domain gradient zone of the carbon interface gradient culture device, uniformly mixing, and then placing an appropriate amount on the balance 7 to weigh, which is the soil sample to be tested in the carbon interface micro-domain gradient zone;

[0085] Before the determination of the soil heavy metal concentration and the determination of the spatial micro-domain variation of CO2 emission, the bulk density of the soil sample to be tested can also be determined by the cutting ring method, and the specific steps include:

[0086] Remove plant residues and small stones from the soil sample to be tested, and place the soil sample to be tested in a well-ventilated and cool place to dry, then grind the soil sample to be tested, and pass it through a 2mm screen to obtain the screened material; test the basic physical and chemical properties of the screened material (including pH, bulk density, heavy metal content, and water potential index).

[0087] S2. Determining the soil heavy metal concentration of the soil sample to be tested by inductively coupled plasma mass spectrometry (ICP-MS) to obtain heavy metal concentration data, including the following steps:

[0088] Weigh 0.1g-0.5g (accurate to 0.0001g) of the soil sample to be tested, then place the sample to be tested in a polytetrafluoroethylene sealed digestion tank, and add three acids to the soil sample to be tested for digestion; then place the digestion tank on the digestion tank support, and then place it in a microwave digestion instrument for digestion, then place it in an acid removal instrument and add 1mL of HClO4 for open acid removal to obtain a solution, and finally transfer the solution to a 50mL volumetric flask to take the supernatant for determination.

[0089] S301. Ex situ culture of the soil sample to be tested, cleaning of the sampling container, and high-concentration sampling of the sample to obtain CO2 emission gas;

[0090] S302. Determining the CO2 emission gas by gas chromatography to obtain CO2 emission data; in these embodiments, the determination of the spatial micro-domain variation of CO2 emission can include ex situ culture, cleaning of the sampling container, and high-concentration sampling of the sample and determination by gas chromatography, which can accurately determine the CO2 emission data in the spatial micro-domain variation of CO2 emission; wherein the ex situ culture includes the following steps:

[0091] A 5.00 g fresh soil sample to be tested is weighed into a 50 mL sealed culture bottle 8 with a rubber stopper, and after incubation in a constant temperature incubator 9 for 6 h, the gas in the bottle is then extracted by a 50 mL syringe 10 and injected into a 12 mL headspace bottle 11, and then the gas in the headspace bottle 11 is subjected to CO2 content determination by a gas chromatograph 12 (model: Agilent 7890A) in combination with the pre-treatment steps of sample container cleaning, sample high concentration collection, sample full-automatic headspace injection and optimized configuration of chromatographic gas circuit.

[0092] S4. According to the heavy metal concentration data and the CO2 emission data, quantitative analysis is performed on the carbon emission determination of the soil sample to be tested.

[0093] Example 3

[0094] As shown in Figure 1 , a carbon interfacial gradient culture device for heavy metal contaminated soil remediation process, comprising:

[0095] A cylindrical culture container 1, the inner height of which is 10 cm, the inner diameter is 20 cm and the thickness is 3 mm, and the four walls of the cylindrical culture container 1 are transparent acrylic sterile plates;

[0096] A separation material layer 2, comprising dialysis bags 4 and multi-layer separation mesh bags 3, the dialysis bags 4 are arranged at the center of the cylindrical culture container 1, and the multi-layer separation mesh bags 3 are arranged around the dialysis bags 4, and different area size carbon interfacial micro-domain gradient zones 5 are formed between adjacent two separation mesh bags 3 to accommodate heavy metal contaminated soil; according to the distance between the carbon interfacial micro-domain gradient zones 5 and the dialysis bags 4, the cylindrical culture container 1 can be divided into I: φ4cm-5cm, II: φ5cm-6cm, III: φ6cm-7cm, IV: φ7cm-8cm, V: φ8cm-9cm and VI: φ9cm-10cm.

[0097] The dialysis bags 4 are used to accommodate liquid biochar-based materials to form heavy metal contaminated soil remediation zones 6.

[0098] The pore size of the separation mesh bags 3 is 500 mesh.

[0099] The cut-off molecular weight of the dialysis bags 4 is 10 kDa.

[0100] The height of the carbon interfacial micro-domain gradient zones 5 is 8 cm (i.e. the height ratio of the carbon interfacial micro-domain gradient zones 5 and the separation material layer 2 is 0.8).

[0101] The distance between adjacent two carbon interfacial micro-domain gradient zones 5 is 1 cm.

[0102] Example 4

[0103] As shown in Figure 1As shown, a carbon interface gradient culture device for a heavy metal contaminated soil remediation process comprises:

[0104] A cylindrical culture container 1 having an inner height of 10 cm, an inner diameter of 20 cm and a thickness of 3 mm, and a transparent acrylic sterile plate as a wall surface;

[0105] A separation material layer 2 comprising a dialysis bag 4 and a multi-layer separation mesh bag 3, the dialysis bag 4 is arranged at the center of the cylindrical culture container 1, and the multi-layer separation mesh bag 3 is arranged around the dialysis bag 4, and different area size carbon interface micro-domain gradient zones 5 are formed between adjacent two separation mesh bags 3 to accommodate heavy metal contaminated soil; according to the distance between the carbon interface micro-domain gradient zone 5 and the dialysis bag 4, the cylindrical culture container 1 can be divided into I: φ4cm-7cm, II: φ7cm-10cm, III: φ10cm-13cm, IV: φ13cm-16cm, V: φ16cm-19cm and VI: φ19cm-22cm.

[0106] The dialysis bag 4 is used to accommodate liquid biochar-based materials to form a heavy metal contaminated soil remediation area 6.

[0107] The pore size of the separation mesh bag 3 is 500 mesh.

[0108] The cut-off molecular weight of the dialysis bag 4 is 15kDa.

[0109] The height of the carbon interface micro-domain gradient zone 5 is 8cm (i.e. the height ratio of the carbon interface micro-domain gradient zone 5 and the separation material layer 2 is 0.8).

[0110] The distance between adjacent two carbon interface micro-domain gradient zones 5 is 3cm.

[0111] Comparative Example 1

[0112] A carbon interface gradient culture device for a heavy metal contaminated soil remediation process comprises:

[0113] A cylindrical culture container 1 having an inner height of 10 cm, an inner diameter of 20 cm and a thickness of 3 mm, and a transparent acrylic sterile plate as a wall surface;

[0114] The separation material layer 2 comprises a plurality of separation bags 3, at least one of which is arranged at the center of the cylindrical culture container 1, and a plurality of separation bags 3 are arranged around the separation bag 3, and different sizes of carbon inter-micro-domain gradient zones 5 are formed between adjacent two separation bags 3 to accommodate heavy metal contaminated soil; according to the distance between the carbon inter-micro-domain gradient zone 5 and the dialysis bag 4, the cylindrical culture container 1 can be divided into I: φ4cm-6cm, II: φ6cm-8cm, III: φ8cm-10cm, IV: φ10cm-13cm, V: φ13cm-16cm and VI: φ16cm-19cm.

[0115] The separation bag 3 contains quartz sand as a blank control material.

[0116] The pore size of the separation bag 3 is 500 mesh.

[0117] The height of the carbon inter-micro-domain gradient zone 5 is 8cm (i.e. the height ratio of the carbon inter-micro-domain gradient zone 5 and the separation material layer 2 is 0.8).

[0118] The distance between adjacent two carbon inter-micro-domain gradient zones 5 is 2cm.

[0119] Comparative Example 2

[0120] As shown in Figure 1 , a carbon inter-gradient culture device for heavy metal contaminated soil remediation process comprises:

[0121] The cylindrical culture container 1 has an inner height of 10cm, an inner diameter of 20cm and a thickness of 3mm, and the four walls of the cylindrical culture container 1 are transparent acrylic sterile plates.

[0122] The separation material layer 2 comprises a dialysis bag 4 and a plurality of separation bags 3, the dialysis bag 4 is arranged at the center of the cylindrical culture container 1, and a plurality of separation bags 3 are arranged around the dialysis bag 4, and different sizes of carbon inter-micro-domain gradient zones 5 are formed between adjacent two separation bags 3 to accommodate heavy metal contaminated soil; according to the distance between the carbon inter-micro-domain gradient zone 5 and the dialysis bag 4, the cylindrical culture container 1 can be divided into I: φ4cm-6cm, II: φ6cm-8cm, III: φ8cm-10cm, IV: φ10cm-13cm, V: φ13cm-16cm and VI: φ16cm-19cm.

[0123] The dialysis bag 4 contains quartz sand.

[0124] The pore size of the separation bag 3 is 500 mesh.

[0125] The cut-off molecular weight of the dialysis bag 4 is 14kDa.

[0126] The height of the carbon interface micro-domain gradient zone 5 is 8 cm (i.e. the height ratio of the carbon interface micro-domain gradient zone 5 and the separation material layer 2 is 0.8).

[0127] The interval between two adjacent carbon interface micro-domain gradient zones 5 is 2 cm.

[0128] Comparative Example 3

[0129] As shown in the accompanying drawings, a carbon interface gradient culture device for heavy metal contaminated soil remediation process comprises: Figure 1 A cylindrical culture container 1, which has an inner height of 10 cm, an inner diameter of 20 cm and a thickness of 3 mm, and the four walls of the cylindrical culture container 1 are transparent acrylic sterile plates;

[0130] A separation material layer 2, which comprises a dialysis bag 4 and a plurality of separation mesh bags 3, the dialysis bag 4 is arranged at the center of the cylindrical culture container 1, and the plurality of separation mesh bags 3 are arranged around the dialysis bag 4, and different area sizes of carbon interface micro-domain gradient zones 5 are formed between two adjacent separation mesh bags 3 to accommodate heavy metal contaminated soil; according to the distance of the carbon interface micro-domain gradient zone 5 and the dialysis bag 4, the cylindrical culture container 1 can be divided into I: φ4cm-6cm, II: φ6cm-8cm, III: φ8cm-10cm, IV: φ10cm-13cm, V: φ13cm-16cm and VI: φ16cm-19cm.

[0131] The dialysis bag 4 contains solid straw biochar material to form a heavy metal contaminated soil remediation area 6.

[0132] The pore size of the separation mesh bag 3 is 500 mesh.

[0133] The molecular weight cut-off of the dialysis bag 4 is 14 kDa.

[0134] The height of the carbon interface micro-domain gradient zone 5 is 8 cm (i.e. the height ratio of the carbon interface micro-domain gradient zone 5 and the separation material layer 2 is 0.8).

[0135] The interval between two adjacent carbon interface micro-domain gradient zones 5 is 2 cm.

[0136] Related experiments and effect data:

[0137] (1) Operation steps:

[0138] A certain dry land soil was collected, deionized water was added to make the soil moisture content 70% of the normal field soil moisture content, and the culture devices of Example 1, Example 3, Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were used for culture in a constant temperature sterile environment for 7 days, respectively.

[0139]

[0140] ​The sampling stage is carried out in different carbon intermicrodomain gradient intervals of different culture devices, and the specific steps include:

[0141] The soil sample to be measured is weighed at 0.1 g to 0.5 g (accurate to 0.0001 g), and then the soil sample to be measured is placed in a closed digestion tank made of polytetrafluoroethylene, and the soil sample to be measured is digested by using a three-acid step digestion method; then the digestion tank is placed on a digestion tank support and placed in a microwave digestion instrument for digestion; then the digestion product is placed in an acid removal instrument and 1 mL of HClO4 is added to the digestion product for open acid removal to obtain a solution; finally, the solution is filtered through a 0.45 μm filter membrane, and the filtrate is transferred to a 50 mL volumetric flask, and the content of heavy metals in the soil is determined.

[0142] 5.00 g of the fresh soil sample to be measured is taken into a 50 mL sealed culture bottle 8 with a rubber plug, and after being cultured in a constant temperature incubator 9 for 6 h, the gas in the bottle is then injected into a 12 mL headspace bottle 11, and then in the pre-treatment steps of sampling container cleaning, sample high concentration collection, sample full-automatic top-space injection and chromatographic gas path optimization configuration, the gas in the headspace bottle 11 is determined for CO2 content by using a gas chromatograph 12 (model: Agilent 7890A).

[0143] The culture devices of Example 1, Example 3, Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 3 are randomly selected for sampling at regular intervals, and the sampling standard is divided into 6 carbon intermicrodomain gradient soil samples to be measured according to the distance from the center of the culture device.

[0144] The experimental results show that:

[0145] Figure 4 An exemplary comparison diagram of the adsorption amount of heavy metal components of heavy metal contaminated soil in the carbon intermicrodomain gradient II in the 7-day culture experiment provided by the embodiments and comparative examples of the present application is shown;

[0146] The results are as follows: Figure 4The adsorption amount of heavy metal Pb in the carbon inter-microdomain gradient II was taken as an example. After the 7-day culture, the adsorption amount of heavy metal Pb by the liquid biochar-based material in the culture device of Example 1 was the largest, reaching 48.51%; followed by Example 3 and Example 4, and the adsorption amount of the liquid biochar-based material in Example 3 and Example 4 was relatively small, and the adsorption amount of heavy metal Pb in both was maintained at 40.32% to 43.09%. The adsorption amount of heavy metal Pb by the adsorption material in Comparative Examples 1 to 3 was maintained at 26.49% to 39.51%, which indicated that the liquid biochar-based material and the culture device provided by the present application achieved short-term adsorption of heavy metal components in the heavy metal contaminated soil within 7 days of culture, so that the liquid biochar-based material can be used to achieve the passivation repair of the soil.

[0147] Figure 5 A comparison diagram of the CO2 emission amount of the carbon inter-microdomain gradient II in the 7-day culture experiment provided by the present application and the comparative examples is shown;

[0148] As shown in Figure 5 , the CO2 emission amount of the soil sample to be tested in the culture device of Comparative Example 1 and Comparative Example 2 was significantly greater than that in the culture device of Example 1, Example 3, Example 4 and Comparative Example 3, wherein the CO2 emission amount of the quartz sand in Comparative Example 1 was the largest, but as the carbon inter-microdomain culture time increased, the difference between the CO2 emission amounts of the soil samples to be tested gradually decreased.

[0149] In particular, in the carbon inter-microdomain gradient II, the CO2 emission amount in the culture device of Comparative Example 1 was about 25.88% to 58.31% more than that in the culture device of Example 1. By the 7th day, the CO2 emission amount of the soil sample to be tested in the culture device of Example 1, Example 3 and Example 4 and the CO2 emission amount of the culture device of Comparative Example 1, Comparative Example 2 and Comparative Example 3 had not yet reached the peak, which indicated that there was sufficient carbon source in the soil to be tested for the microorganisms to utilize, and also indirectly indicated that the headspace of the culture device of the present application was sufficient, and the CO2 emission amount of the soil to be tested in the process of passivation of the heavy metal pollutants in the soil could be accurately determined.

[0150] In summary, the carbon intergradient culture device for heavy metal contaminated soil remediation process provided by the embodiment of the application can selectively culture heavy metal contaminated soil 5 by setting a separation material layer 2 in the cylindrical culture container 1, and the separation material layer 2 can include a dialysis bag 4 and a multi-layer separation net bag 3, and different heavy metal contaminated soils 5 can be physically blocked by the separation net bag 3 to avoid mutual influence between the heavy metal contaminated soils 5, so that the heavy metal contaminated soil 5 can be selectively cultured; and the liquid biochar-based material contained in the dialysis bag 4 can promote gas exchange between the liquid biochar-based material in the dialysis bag 4 and the carbon intergradient zone formed between the separation net bag 3, and form a heavy metal contaminated soil remediation area 6 to effectively adsorb heavy metals in the carbon intergradient zone, reduce the toxic effect of heavy metal components on microorganisms in the heavy metal soil, so that the carbon sequestration capacity of the heavy metal contaminated soil can be improved in the passivation and remediation process of the heavy metal contaminated soil, and the accuracy of the determination of CO2 emission gas in the culture process of the culture device can be improved; the carbon intergradient culture device can realize the zoned culture of heavy metal contaminated soils with different carbon intergradient and the effective adsorption of heavy metal components in the passivation and remediation of soil heavy metal pollution, and the accurate determination of CO2 emission gas in the culture stage, so that the quantitative analysis of carbon emission of the carbon intergradient of the heavy metal contaminated soil in the passivation and remediation process of the soil heavy metal pollution can be realized.

[0151] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values in the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers in the described range, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) in the indicated range.

[0152] In the present application, the orientation words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the present application, the terms "comprise", "contain" and the like mean "comprise but not limited to". In the present text, the relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. In the present text, the "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: the case of A alone, the case of A and B existing at the same time, and the case of B alone. Wherein A, B can be singular or plural. In the present text, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of these items, including any combination of single item or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent: a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b, c can be single or multiple.

[0153] The above description is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A char- interface gradient cultivation device for heavy metal contaminated soil remediation process, characterized in that, The carbon interface gradient culture device comprises: a cylindrical culture container (1); a layer of separation material (2) comprising a dialysis bag (4) and a plurality of layers of separation mesh bags (3), the dialysis bag (4) being arranged at the center of the cylindrical culture container (1), the plurality of layers of separation mesh bags (3) being arranged around the dialysis bag (4), and adjacent two of the separation mesh bags (3) forming carbon interface micro-domain gradient zones (5) of different sizes to accommodate heavy metal contaminated soil; the dialysis bag (4) being used to accommodate liquid biochar-based material to form a heavy metal contaminated soil remediation area (6); the separation mesh bags (3) have a pore size of ≤500 mesh; the height ratio of the carbon interface micro-domain gradient zones (5) to the layer of separation material (2) is ≤0.8; the distance between adjacent two of the carbon interface micro-domain gradient zones (5) is 1cm-3cm.

2. The interfacial gradient culture device of claim 1, wherein, The dialysis bag (4) has a molecular weight cut-off of 10kDa-15kDa.

3. The interfacial gradient culture device of claim 1, wherein, The liquid biochar-based material comprises an aqueous solution of straw biochar material.

4. Use of a char interface gradient cultivation device for a heavy metal contaminated soil remediation process, characterized in that, The application comprises using the carbon interface gradient culture device according to any one of claims 1-3 in quantitative analysis of carbon emission determination.

5. Use according to claim 4, characterized in that, The quantitative analysis of carbon emission determination comprises the steps of: sampling heavy metal soil in different carbon interface micro-domain gradient zones in the carbon interface gradient culture device to obtain a soil sample to be tested; determining the concentration of heavy metals in the soil sample to be tested to obtain heavy metal concentration data; determining the spatial micro-domain variation of CO2 emission of the soil sample to be tested to obtain CO2 emission data; performing quantitative analysis of carbon emission determination on the soil sample to be tested according to the heavy metal concentration data and the CO2 emission data.

6. Use according to claim 5, characterized in that, The determination of the spatial micro-domain variation of CO2 emission of the soil sample to be tested to obtain CO2 emission data comprises the steps of: performing ex situ culture, sampling container cleaning and sample high-concentration collection on the soil sample to be tested to obtain CO2 emission gas; determining the CO2 emission gas by gas chromatography to obtain CO2 emission data.

7. Use according to claim 5, characterized in that, The determination of the concentration of heavy metals in the soil comprises determining the concentration of heavy metals in the soil by inductively coupled plasma mass spectrometry.

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