A soil remediation reagent, a preparation method and a remediation method thereof

Abstract

The application relates to the technical field of soil remediation, and particularly discloses a soil remediation reagent, a preparation method thereof and a remediation method. The preparation method of the soil remediation reagent comprises the following steps: inoculating bacillus subtilis into a culture medium containing ligusticum wallichii, culturing to obtain modified bacterial liquid, adding the modified bacterial liquid into a mixture of humic acid, distiller's grains and oyster shell powder, and fermenting to obtain the remediation reagent. The modified bacterial liquid containing modified bacillus subtilis is added into the mixture of humic acid, distiller's grains and oyster shell powder, and after fermentation, on one hand, the fermentation product can be used as a long-term survival carrier of the bacillus subtilis, and on the other hand, the fermentation product can provide nutrients required by plants. After the fermentation product is added into soil contaminated by carbamates, the carbamates can be degraded, the soil fertility can be improved, and the growth and development of plants can be promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation, in particular to a soil remediation reagent, a preparation method and a remediation method thereof. BACKGROUND

[0002] Carbamate pesticides are a kind of pesticide chemicals, and the main component is carbamate. Carbamate pesticides are widely used in agriculture, horticulture and forestry and other fields. In agriculture, carbamate pesticides can be used for the prevention and treatment of crops such as rice fields, orchards, vegetables, tea, fruits, etc. In forestry, it is usually used for the prevention and treatment of forest pests. Carbamate has certain toxicity to plants and human bodies, and long-term existence in the soil will affect the growth and development of vegetation, and may also pollute water sources and other hazards to human health. SUMMARY

[0003] In view of the harm of carbamate to vegetation, environment and human body, the present application proposes a scheme for degrading carbamate.

[0004] In a first aspect, the present application proposes a preparation method of a soil remediation reagent, and adopts the following technical scheme.

[0005] A preparation method of a soil remediation reagent, Bacillus subtilis is inoculated into a culture medium containing ligusticum wallichii, and a modified bacterial liquid is obtained by culture. The modified bacterial liquid is added to a mixture of humic acid, distiller's grains and oyster shell powder, and the remediation reagent is obtained by fermentation.

[0006] By adopting the above technical scheme, Bacillus subtilis can produce antibiotic substances and bacteriolysis substances that can inhibit the growth of bacteria, viruses, fungi and pathogens, and can improve the stress resistance of crops, promote plant growth and increase the yield of agricultural products, and is relatively friendly to the environment. The modified Bacillus subtilis can produce good carbamate degradation function. Humic acid is a kind of organic matter caused and accumulated by a series of processes of microbial decomposition and transformation of animal and plant remains (mainly plant remains) and geochemistry. Humic acid can not only supplement nutrients for soil, but also chelate heavy metal ions in soil, and has a certain remediation effect on soil. Distiller's grains are the residues left after rice, wheat, sorghum and other grains are brewed into wine, and are rich in nutrients. The main component of oyster shell is calcium carbonate, and it also contains magnesium, copper, iron, zinc, potassium, molybdenum, phosphorus, manganese elements, and contains a variety of amino acids. After the modified bacterial liquid containing modified Bacillus subtilis is added to the mixture of humic acid, distiller's grains and oyster shell powder, and fermentation, on the one hand, the fermentation product can be used as a long-term survival carrier for Bacillus subtilis, and on the other hand, the fermentation product can provide nutrients required by plants. After the fermentation product is added to the soil contaminated by carbamate, it can not only degrade carbamate, but also improve soil fertility and promote plant growth and development.

[0007] Preferably, the culture medium further comprises soybean meal, corn meal and wort, and the mass ratio of the soybean meal, the corn meal, the wort and the ligusticum wallichii is 100:(30-50):(60-80):(5-10).

[0008] By using the above technical solution, the soybean meal, the corn meal and the wort provide nutrients for the bacillus subtilis, and the ligusticum wallichii modifies the bacillus subtilis, so that the bacillus subtilis has good ability to degrade carbamate.

[0009] Preferably, the culture process is performed under the following conditions: the culture medium is loaded into a container, the temperature is controlled at 28-32℃, the pH is controlled at 7.0-7.5, the dissolved oxygen saturation is maintained at 10-20%, the bacillus subtilis is added, and the modified bacterial solution is obtained after 3-7 days of culture.

[0010] By using the above technical solution, under the culture conditions, the bacillus subtilis grows and develops quickly and gradually develops the ability to degrade carbamate.

[0011] Preferably, the mass ratio of the modified bacterial solution, the humic acid, the wine lees and the oyster shell powder is 1:(5-10):(80-160):(100-200).

[0012] By using the above technical solution, the bacillus subtilis can be fully reproduced, and the bacillus subtilis can fully ferment the humic acid, the wine lees and the oyster shell powder. The fermentation product provides a long-term survival environment for the bacillus subtilis, and the fermentation product also produces good fertility and can repair carbamate pollution and improve soil fertility.

[0013] Preferably, the fermentation process is performed under the following conditions: the modified bacterial solution, the humic acid, the wine lees and the oyster shell powder are placed into a fermentation container, sterile water is added and stirred uniformly, and the fermentation culture is performed at a temperature of 28-32℃ for 7-13 days to obtain the repair agent.

[0014] By using the above technical solution, the repair agent obtained by fermentation has good ability to degrade carbamate in the soil and can also improve the soil environment.

[0015] In a second aspect, the present application further provides a soil repair agent, and the following technical solution is used.

[0016] A soil repair agent is prepared according to the above preparation method.

[0017] By adopting the technical scheme, the soil remediation agent with good ability of degrading the carbamate in the soil and improving the soil environment is prepared by a relatively economical preparation method.

[0018] In a third aspect, the application further provides a soil remediation method, and adopts the following technical scheme.

[0019] A soil remediation method, wherein the soil remediation agent is mixed into the carbamate-contaminated soil to degrade the carbamate.

[0020] By adopting the technical scheme, the soil remediation method can effectively degrade the carbamate.

[0021] In a preferred scheme of the soil remediation method, the mass ratio of the soil remediation agent to the carbamate-contaminated soil is 1:(5-15).

[0022] By adopting the technical scheme, the soil remediation method can effectively degrade the carbamate.

[0023] In summary, the soil remediation agent, the preparation method and the remediation method of the application have the following beneficial effects:

[0024] The modified bacteria liquid containing the modified Bacillus subtilis is added into the mixture of humic acid, distiller's grains and oyster shell powder, and after fermentation, on one hand, the fermentation product can be used as a long-term survival carrier of Bacillus subtilis, and on the other hand, the fermentation product can provide nutrients required by plants. After the fermentation product is added into the carbamate-contaminated soil, the carbamate can be degraded, the soil fertility can be improved, and the growth and development of plants can be promoted. The soil remediation agent with good ability of degrading the carbamate in the soil and improving the soil environment is prepared by a relatively economical preparation method.

[0025] The scheme of the application provides a recycling path of humic acid, distiller's grains and oyster shell. The soil remediation agent prepared by the application can be mixed into the carbamate-contaminated soil to effectively degrade the carbamate in the soil and improve the soil fertility. DETAILED DESCRIPTION

[0026] The distiller's grains used in the following examples and comparative examples are a mixture of three solid residues obtained by solid-state fermentation and distillation of sorghum, wheat and corn as raw materials in a mass ratio of 1:1:1.

[0027] Example 1

[0028] In this example, a soil remediation agent is prepared by the following preparation method.

[0029] The soybean meal, corn flour, malt juice and ligusticum wallichii are mixed in a mass ratio of 100:40:70:8 to obtain a culture medium.

[0030] The bacillus subtilis is inoculated into sterile water in a mass ratio of 1:50, cultured in a 30°C constant temperature incubator for 5h to obtain a bacillus subtilis seed liquid.

[0031] The culture medium is loaded into a fermenter, the temperature is controlled at 30°C, the pH is regulated at 7.0-7.5, the dissolved oxygen saturation is maintained at 10-20%, the bacillus subtilis seed liquid is added, and the modified bacteria liquid is obtained after 5 days of culture. The mass ratio of the culture medium and the bacillus subtilis seed liquid is 30:1.

[0032] The modified bacteria liquid, humic acid powder, distiller's grains powder and oyster shell powder are proportioned in a mass ratio of 1:8:120:150, the proportioned modified bacteria liquid, humic acid powder, distiller's grains powder and oyster shell powder are placed into a fermentation container, sterile water is added and stirred uniformly, and the repair reagent is obtained after 10 days of fermentation culture at a temperature of 30°C.

[0033] Comparative Example 1

[0034] The repair reagent is prepared by using a scheme basically same as that of Example 1, and the only difference is that the use of ligusticum wallichii is cancelled in the present comparative example. The specific preparation method is as follows.

[0035] The soybean meal, corn flour and malt juice are mixed in a mass ratio of 100:40:70 to obtain a culture medium.

[0036] The bacillus subtilis is inoculated into sterile water in a mass ratio of 1:50, cultured in a 30°C constant temperature incubator for 5h to obtain a bacillus subtilis seed liquid.

[0037] The culture medium is loaded into a fermenter, the temperature is controlled at 30°C, the pH is regulated at 7.0-7.5, the dissolved oxygen saturation is maintained at 10-20%, the bacillus subtilis seed liquid is added, and the modified bacteria liquid is obtained after 5 days of culture. The mass ratio of the culture medium and the bacillus subtilis seed liquid is 30:1.

[0038] The modified bacteria liquid, humic acid powder, distiller's grains powder and oyster shell powder are proportioned in a mass ratio of 1:8:120:150, the proportioned modified bacteria liquid, humic acid powder, distiller's grains powder and oyster shell powder are placed into a fermentation container, sterile water is added and stirred uniformly, and the repair reagent is obtained after 10 days of fermentation culture at a temperature of 30°C.

[0039] Comparative Example 2

[0040] The comparative example uses the same scheme as example 1 to prepare the repair reagent, the only difference is that the comparative example uses kudzu instead of ligusticum, the specific preparation method is as follows.

[0041] The soybean meal, corn flour, wort and kudzu were mixed in a mass ratio of 100:40:70:8 to obtain a culture medium.

[0042] According to the mass ratio of bacillus subtilis and sterile water 1:50, bacillus subtilis was inoculated into sterile water, and cultured in a 30℃ constant temperature incubator for 5h to obtain bacillus subtilis seed liquid.

[0043] The culture medium was loaded into the fermenter, the temperature was controlled at 30℃, the pH was regulated at 7.0-7.5, the dissolved oxygen saturation was maintained at 10-20%, the bacillus subtilis seed liquid was added, and the modified bacteria liquid was obtained after 5 days of culture. The mass ratio of culture medium and bacillus subtilis seed liquid is 30:1.

[0044] According to the mass ratio of modified bacteria liquid, humic acid powder, distiller's grains powder, oyster shell powder 1:8:120:150, the modified bacteria liquid, the humic acid powder, the distiller's grains powder and the oyster shell powder were placed into the fermentation container, sterile water was added and stirred uniformly, and fermented at 30℃ for 10 days to obtain the repair reagent.

[0045] Comparative example 3

[0046] The comparative example uses the same scheme as example 1 to prepare the repair reagent, the only difference is that the comparative example uses radix polygoni multiflori instead of ligusticum, the specific preparation method is as follows.

[0047] The soybean meal, corn flour, wort and radix polygoni multiflori were mixed in a mass ratio of 100:40:70:8 to obtain a culture medium.

[0048] According to the mass ratio of bacillus subtilis and sterile water 1:50, bacillus subtilis was inoculated into sterile water, and cultured in a 30℃ constant temperature incubator for 5h to obtain bacillus subtilis seed liquid.

[0049] The culture medium was loaded into the fermenter, the temperature was controlled at 30℃, the pH was regulated at 7.0-7.5, the dissolved oxygen saturation was maintained at 10-20%, the bacillus subtilis seed liquid was added, and the modified bacteria liquid was obtained after 5 days of culture. The mass ratio of culture medium and bacillus subtilis seed liquid is 30:1.

[0050] According to the mass ratio of the modified bacteria liquid, the humic acid powder, the distiller's grains powder and the oyster shell powder is 1:8:120:150, the modified bacteria liquid, the humic acid powder, the distiller's grains powder and the oyster shell powder are put into a fermentation container, sterile water is added and stirred uniformly, and fermentation culture is carried out at 30℃ for 10 days, so that the repair reagent is obtained.

[0051] Application example

[0052] A soil repair method, the soil repair reagents prepared by example 1, comparative example 1-3 are added into the same batch of carbamate contaminated soil respectively to degrade the carbamate, the mass ratio of the soil repair reagent and the carbamate contaminated soil in the four groups of samples is 1:10, and the degradation time is 7 days.

[0053] Application result detection

[0054] The concentration of carbamate in the soil is tested by gas chromatography-mass spectrometry, the concentration of carbamate before and after adding the repair reagent in the four groups of samples is detected respectively, and a blank control group of soil standing for 7 days without adding the repair reagent is set.

[0055] Firstly, 500g of soil is collected and divided into 5 groups of soil, each group of soil is 100g, and each group of soil is dispersed and refined, 1mL of carbamate solution with a mass concentration of 0.01g / mL is sprayed on each group of soil, and each group of soil is mixed uniformly.

[0056] Then, 10g of the repair reagent prepared by example 1, 10g of the repair reagent prepared by comparative example 1, 10g of the repair reagent prepared by comparative example 2, and 10g of the repair reagent prepared by comparative example 3 are added into 4 groups of soil respectively, and the 5th group of soil is not added with the repair reagent, and all are standing for 7 days.

[0057] Each group of soil is dissolved with 100mL of dichloromethane for multiple times, and is stirred and shaken during dissolution to fully dissolve the carbamate therein; then the dissolved liquid is combined and centrifuged, the supernatant is combined, filtered, and 5 groups of test solutions are obtained. The results of detecting the concentration of carbamate in the 5 groups of test solutions by gas chromatography-mass spectrometry are shown in table 1.

[0058] Table 1: results of degrading carbamate

[0059]

[0060] The results of Table 1 show that the soil remediation agent prepared in Example 1 can effectively degrade the carbamate pollutants in the soil; the Bacillus subtilis in Comparative Example 1 is not modified with ligusticum wallichii, and thus the soil remediation agent prepared therefrom has no obvious effect on degrading carbamate; the Bacillus subtilis in Comparative Example 2 is modified with pueraria instead of ligusticum wallichii, and thus the soil remediation agent prepared therefrom has very limited effect on degrading carbamate. The Bacillus subtilis in Comparative Example 3 is modified with radix polygoni multiflori instead of ligusticum wallichii, and thus the soil remediation agent prepared therefrom has no obvious effect on degrading carbamate.

[0061] In summary, the Bacillus subtilis is first modified by culturing with ligusticum wallichii to obtain a modified bacteria solution, and then the modified bacteria solution containing the modified Bacillus subtilis is added into a mixture of humic acid, distiller's grains and oyster shell powder, and after fermentation, on the one hand, the fermentation product can be used as a long-term survival carrier of the Bacillus subtilis, and on the other hand, the fermentation product produces nutrients required by plants. After the fermentation product is added into the soil contaminated with carbamate, the carbamate can be degraded, and the soil fertility can be improved to promote the growth and development of plants. The soil remediation agent prepared by the relatively economical preparation method has good ability to degrade the carbamate in the soil and can also improve the soil environment. The soil remediation agent prepared by the present application can effectively degrade the carbamate in the soil and improve the soil fertility when mixed into the soil contaminated with carbamate, and thus has a wide application prospect.

[0062] The above are only some embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. For those skilled in the art, some improvements and refinements without departing from the creative design of the present application should also fall within the protection scope of the present application.

Claims

1. A method for preparing a soil remediation reagent, characterized in that, Bacillus subtilis was inoculated into a culture medium containing Ligusticum striatum to obtain a modified bacterial solution. The modified bacterial solution was then added to a mixture of humic acid, distiller's grains, and oyster shell powder and fermented to obtain the repair reagent. The culture medium also contains soybean meal, corn flour and malt extract; the mass ratio of the soybean meal, the corn flour, the malt extract and the ligusticum is 100:(30-50):(60-80):(5-10). The conditions for the cultivation process include: filling the container with the culture medium, controlling the temperature at 28-32℃, adjusting the pH to 7.0-7.5, maintaining the dissolved oxygen saturation at 10-20%, adding Bacillus subtilis, and culturing for 3-7 days to obtain the modified bacterial solution; The soil remediation reagent is used to mix into soil contaminated with carbamates to degrade carbamates.

2. The method for preparing the soil remediation reagent according to claim 1, characterized in that, The mass ratio of the modified bacterial solution, the humic acid, the distiller's grains, and the oyster shell powder is 1:(5-10):(80-160):(100-200).

3. The method for preparing the soil remediation reagent according to claim 2, characterized in that, The fermentation process conditions include: placing the modified bacterial solution, the humic acid, the distiller's grains and the oyster shell powder into a fermentation container, adding sterile water and stirring evenly, and fermenting and culturing at a temperature of 28-32℃ for 7-13 days to obtain the repair reagent.

4. A soil remediation reagent, characterized in that, Prepared by the preparation method according to any one of claims 1-3.

5. A soil remediation method, characterized in that, The soil remediation reagent described in claim 4 is mixed into the soil contaminated with carbamate to degrade carbamate.

6. The soil remediation method according to claim 5, characterized in that, The mass ratio of the soil remediation reagent to the carbamate-contaminated soil is 1:(5~15).

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