阅读说明：本技术 一种农业活动区土壤层有机农药的微生物修复方法 (Microbial remediation method for organic pesticide in soil layer of agricultural activity area ) 是由 王雷 席北斗 李翔 檀文炳 王金生 李彤彤 崔东宇 闫政 李一葳 郭可昕 李艳平 于 2020-09-14 设计创作，主要内容包括：本发明公开了一种农业活动区土壤层有机农药的微生物修复方法,通过选择对没有环境负荷的微生物进行修复,尤其是与体相零价铁改性生物炭材料修复有机组合起来,特别是通过精心选择的适宜微生物与具有长期稳定应用性的体相零价铁改性生物炭材料,对有机农药去除效果显著。(The invention discloses a microbial remediation method for organic pesticides in soil layers of agricultural activity areas, which is characterized in that microbes without environmental load are selected to be remediated, and particularly organically combined with bulk phase zero-valent iron modified biochar material remediation, and particularly, the organic pesticides are removed remarkably through carefully selected appropriate microbes and bulk phase zero-valent iron modified biochar materials with long-term stable applicability.)

1. A microbial remediation method for organic pesticides in soil layers of agricultural activity areas adopts a microbial agent to remediate soil polluted by organic pesticides, wherein the microbial agent comprises bacillus subtilis and bacillus licheniformis, and preferably the number ratio of the bacillus subtilis to the bacillus licheniformis is (2-4) to (2-3).

2. The method for the microbial remediation of an organic pesticide from a soil layer in an agricultural activity area of claim 1, wherein the ratio of the number of bacillus subtilis to the number of bacillus licheniformis is 3: 2.

3. The method for microbial remediation of an organic pesticide from a soil layer in an agricultural activity area of claim 1, wherein the microbial inoculum further comprises lactic acid bacteria, and the ratio of the number of bacillus subtilis, bacillus licheniformis and lactic acid bacteria is (2-4) to the number of lactic acid bacteria (2-3): (1-2).

4. The method for microbial remediation of an organic pesticide of a soil layer of an agricultural activity area of claim 3, wherein the ratio of the number of Bacillus subtilis, Bacillus licheniformis and lactic acid bacteria is 3:2: 1.

5. The microbial remediation method of organic pesticides in soil layers of an agricultural activity area of claim 1, wherein a bulk zero-valent iron-loaded biochar material obtained by pyrolytically carbonizing an iron-rich biomass, which is ramie planted in acid red soil, in an oxygen-free atmosphere is further added to the organic pesticide-contaminated soil before the microbial inoculum is inoculated.

6. The microbial remediation method of claim 5 wherein said bulk zero-valent iron-loaded biochar material has zero-valent iron nanoparticles dispersively embedded in the biochar bulk phase.

7. The microbial remediation method of an organic pesticide in a soil layer of an agricultural activity area of claim 6, wherein the bulk zero-valent iron-loaded biochar material is obtained by subjecting iron-rich vegetative biomass to pyrolytic carbonization at a temperature of 500-900 ℃.

8. The microbial remediation method of an organic pesticide in a soil layer of an agricultural activity area of claim 7, wherein the bulk zero-valent iron-loaded biochar material is obtained by subjecting iron-rich plant biomass to pyrolysis carbonization at the temperature of 700-900 ℃.

9. The microbial remediation method of an organic pesticide of a soil layer of an agricultural active area of claim 7, wherein the pyrolytic carbonization time is 1 to 3 hours, preferably 1.5 to 2 hours.

10. The microbial remediation method of organic pesticides of soil layers of agricultural activity areas of claim 1, wherein after remediation of organic pesticide contaminated soil with microbial agents, humic acid organic fertilizer is applied, the humic acid organic fertilizer being produced by: cutting crop straws into 2-5 cm segments, mixing 60-80 parts by weight of animal wastes, 10-20 parts by weight of straw particles and 10-20 parts by weight of vinasse, spraying an organic fertilizer starter, stacking and fermenting for 10-15 days at a fermentation temperature not higher than 70 ℃, and adding 1-4 parts of humic acid after fermentation.

Technical Field

The invention relates to the field of environmental protection, in particular to a microbial remediation method for soil polluted by organic pesticides.

Background

An agricultural activity area, which is an area where agricultural production activities are performed, generally refers to an area where food crops and cash crops are mainly planted, centered on the farming industry. The most important data in the agricultural activity area is soil.

As agricultural activities are exacerbated, the greater the frequency and amount of organic pesticides used. The organic pesticide mainly comprises organochlorine pesticide, organophosphorus pesticide, organic nitrogen pesticide and the like, and all of the organic pesticide has strong biological toxicity. After the organic pesticide is applied, the organic pesticide can be partially scattered in the soil, and even some organic pesticides are directly applied to the soil, so that the soil in an agricultural activity area is polluted.

The soil in agricultural activity areas is increasingly polluted by organic pesticides. Because the organic pesticide is difficult to degrade, even if the degradation product of the organic pesticide also has biological toxicity, the harm caused by the organic pesticide pollution is serious. Moreover, organic pesticides sometimes promote the accumulation of some heavy metals, which in turn can lead to heavy metal contamination.

The organic pesticide contaminated soil is subjected to more repairing researches, and the microorganism repairing technology is concerned more now and plays an increasingly important role in the organic pesticide contaminated soil.

In the research on the treatment of organic sewage, researchers find that the zero-valent iron modified biochar has a good removing effect on organic pesticides and hardly causes secondary pollution.

Disclosure of Invention

The inventor researches and discovers that: for the organic pesticide pollution of the soil layer of the agricultural activity area, the organic pesticide removing effect is obvious by selecting microorganisms without environmental load to repair, particularly organically combining with bulk phase zero-valent iron modified biochar material repair, and particularly by carefully selecting suitable microorganisms and bulk phase zero-valent iron modified biochar material with long-term stable applicability.

The object of the present invention is to provide the following:

the invention provides a microbial remediation method of organic pesticides in soil layers of agricultural activity areas, which is characterized in that microbial agents are adopted to remediate soil polluted by the organic pesticides, wherein the microbial agents comprise bacillus subtilis and bacillus licheniformis, and preferably, the number ratio of the bacillus subtilis to the bacillus licheniformis is (2-4) to (2-3).

The invention also provides a microbial remediation method of the organic pesticide in the soil layer of the agricultural activity area, wherein the quantity ratio of the bacillus subtilis to the bacillus licheniformis is 3: 2.

The third aspect of the invention provides the microbial remediation method of the organic pesticide in the soil layer of the agricultural activity area, wherein the microbial agent further comprises lactic acid bacteria, and the quantity ratio of the bacillus subtilis, the bacillus licheniformis and the lactic acid bacteria is (2-4) to (2-3): (1-2).

The invention also provides a microbial remediation method of the organic pesticide in the soil layer of the agricultural activity area, wherein the quantity ratio of the bacillus subtilis to the bacillus licheniformis to the lactic acid bacteria is 3:2: 1.

In a fifth aspect, the invention provides a microbial remediation method for organic pesticides in soil layers of agricultural activity areas, wherein before inoculation of the microbial inoculum, bulk zero-valent iron-loaded biochar materials are further added into the organic pesticide contaminated soil, the bulk zero-valent iron-loaded biochar materials are obtained by pyrolyzing and carbonizing iron-rich biomass in an oxygen-free atmosphere, and the iron-rich biomass is ramie planted in acid red soil.

The invention provides a microbial remediation method of the organic pesticide in the soil layer of the agricultural activity area, wherein the bulk phase zero-valent iron loads the biochar material, and the zero-valent iron nanoparticles are dispersedly embedded in the biochar bulk phase.

The seventh aspect of the invention provides the microbial remediation method for the organic pesticide in the soil layer of the agricultural activity area, wherein the bulk phase zero-valent iron-loaded biochar material is obtained by performing pyrolysis and carbonization on iron-rich plant biomass at the temperature of 500-900 ℃.

The eighth aspect of the invention provides a microbial remediation method for the organic pesticide in the soil layer of the agricultural activity area, wherein the bulk phase zero-valent iron-loaded biochar material is obtained by performing pyrolysis and carbonization on iron-rich plant biomass at the temperature of 700-900 ℃.

The ninth aspect of the present invention provides the microbial remediation method for organic pesticides in soil layers of agricultural activity areas, wherein the pyrolysis carbonization time is 1 to 3 hours, preferably 1.5 to 2 hours.

The tenth aspect of the invention provides a microbial remediation method for organic pesticides in soil layers of agricultural activity areas, wherein after organic pesticide contaminated soil is remediated by using a microbial agent, a humic acid organic fertilizer is applied, and the humic acid organic fertilizer is prepared by the following steps: cutting crop straws into 2-5 cm segments, mixing 60-80 parts by weight of animal wastes, 10-20 parts by weight of straw particles and 10-20 parts by weight of vinasse, spraying an organic fertilizer starter, stacking and fermenting for 10-15 days at a fermentation temperature not higher than 70 ℃, and adding 1-4 parts of humic acid after fermentation.

The microbial remediation method for the organic pesticide in the soil layer of the agricultural activity area, provided by the invention, has the following advantages:

(1) the invention selects the composite microbial inoculum consisting of bacillus subtilis and bacillus licheniformis, particularly the composite microbial inoculum consisting of bacillus subtilis, bacillus licheniformis and lactobacillus as the repairing microorganism, and the bulk phase zero-valent iron is matched to load the biochar material, so that the repairing effect on the organic pesticide in the soil layer of the agricultural activity area is obvious, and the organic pesticide is almost removed after the repairing.

(2) The microbial remediation microbial inoculum selected by the invention can not cause exogenous secondary pollution to the soil of the agricultural activity area, thereby ensuring the remediation effect.

(3) The zero-valent iron phase load biochar material prepared from the iron-rich biomass can obviously remove organic pesticides in soil, and can further promote the removal of the organic pesticides under the coordination with microorganisms.

(4) The zero-valent iron phase prepared from the iron-rich biomass is loaded with the biochar material, zero-valent iron is loaded in the biochar phase in situ, and the nano zero-valent iron is high in load amount and has a stable and long-term lasting repairing effect.

(5) According to the invention, after the zero-valent iron phase loaded biochar material and the microorganisms are respectively utilized to repair the soil polluted by the organic pesticide, the humic acid organic fertilizer is supplemented, so that the soil environment is improved, and the removal rate of the organic pesticide is further improved.

Detailed Description

The present invention will be described in further detail below with reference to preferred embodiments and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

In the invention, the composite microbial agent consisting of bacillus subtilis and bacillus licheniformis is used as a microbial repairing agent, so that organic pesticide pollution of farmlands can be remarkably repaired, and the soil environment is hardly influenced or damaged.

In a preferred embodiment, the ratio of the number of Bacillus subtilis to Bacillus licheniformis is (2-4): (2-3), preferably 3: 2. in this case, the effect of removing the organic pesticide in the soil is desirable.

In a preferred embodiment, the microbial remediation agent used in the present invention further comprises lactic acid bacteria, which facilitate the removal of the organic pesticide. Preferably, the quantity ratio of the bacillus subtilis, the bacillus licheniformis and the lactic acid bacteria is (2-4) to (2-3): (1-2) more preferably, the ratio of the number of Bacillus subtilis, Bacillus licheniformis and lactic acid bacteria is 3:2:1, in which case the overall remediation effect on organic pesticides in soil is excellent.

In the present invention, Bacillus subtilis, Bacillus licheniformis and lactic acid bacteria are not particularly limited, and commercially available bacteria can be used or self-cultured.

The Bacillus subtilis is enlarged and cultured to 1 x 10⁸CFU/ml, bacillus licheniformis expansion culture to 1X 10⁸CFU/ml, and then mixing according to the volume ratio of (2-4) to (2-3), preferably 3:2 to obtain the microbial agent for repairing.

In a preferred embodiment, Bacillus subtilis is grown to 1X 10⁸CFU/ml, bacillus licheniformis expansion culture to 1X 10⁸CFU/ml, lactic acid bacteria expansion culture to 1 × 10⁸CFU/ml, and then according to the volume ratio of (2-4) to (2-3): (1-2), preferably 3:2:1, to obtain a microbial agent for repairing.

In the case of remediating soil contaminated with an organic pesticide in an agricultural active area, the amount of the microorganism to be inoculated as a microorganism bacterium agent for remediation is 20 to 60ml/kg of soil, preferably 40 to 60ml/kg of soil, more preferably 50ml/kg of soil.

As an alternative embodiment, bacillus subtilis, bacillus licheniformis and lactic acid bacteria can be respectively and independently inoculated into the organic pesticide contaminated soil.

When the soil polluted by organic pesticide in an agricultural activity area is repaired, the inventor finds that the repairing effect of the bulk phase zero-valent iron loaded biochar material is very good, and particularly, the effect is more excellent when the microbial repairing is carried out after the bulk phase zero-valent iron loaded biochar material is adopted.

In the invention, the bulk phase zero-valent iron modified biochar material is obtained by pyrolyzing and carbonizing iron-rich plant biomass under an anaerobic condition, and the iron-rich plant is preferably ramie.

As an iron-rich plant ramie, the ramie is planted in the acid red soil for more than 3 months. Because the iron content in the acid red soil is high, the method is favorable for absorbing and enriching iron in ramie. Furthermore, in order to promote the enrichment of iron in the ramie, dilute citric acid solution and the like can be applied in the ramie planting period if necessary.

The ramie has high fiber content, and the bulk phase zero-valent iron-loaded biochar material obtained from the ramie has better performance, such as large specific surface area and the like, and is favorable for the bulk phase zero-valent iron-loaded biochar material to have higher and more stable repair capability.

When the homogeneous zero-valent iron modified biochar material is obtained, the pyrolysis carbonization temperature is preferably within the temperature range of 500-900 ℃, more preferably within the temperature range of 700-900 ℃, and in this case, the bulk phase loaded zero-valent iron biochar material with stable and durable modification capability can be obtained.

The pyrolysis carbonization time of the iron-rich plant biomass is preferably 1 to 3 hours, more preferably 1.5 to 2 hours. Under the pyrolysis carbonization time, the zero-valent iron load in the obtained bulk phase zero-valent iron-loaded charcoal material is relatively high, and the reaction repair capability of the bulk phase zero-valent iron-loaded charcoal material is stable and durable.

In a preferred embodiment of the method for remediating organic pesticide in the soil layer of the agricultural activity area, persulfate is used in combination when the bulk phase loaded zero-valent iron biochar material is used for remediating organic pesticide contaminated soil.

The inventor finds that when the bulk phase load zero-valent iron biochar material and persulfate are jointly used, the removal speed of the organic pesticide is obviously improved, and the removal efficiency is further improved.

However, when a persulfate such as potassium persulfate is used, it is not preferable to add it too much in view of the high reactivity of the persulfate, and the amount to be added may be controlled to be not more than half, preferably not more than 35 wt%, more preferably about 10 wt% of the weight of the zero-valent iron-bearing biochar material in the bulk phase.

In the invention, after the organic pesticide contaminated soil is repaired by adopting the bulk phase loaded zero-valent iron biochar material and the microorganisms, the humic acid organic fertilizer can be applied to the repaired soil, so that the consolidation repairing effect is promoted, and the comprehensive performance of the soil is improved.

In a preferred embodiment, the humic acid organic fertilizer is prepared by: cutting crop straws into 2-5 cm segments, mixing 60-80 parts by weight of animal wastes, 10-20 parts by weight of straw particles and 10-20 parts by weight of vinasse, spraying an organic fertilizer starter, stacking and fermenting for 10-15 days at a fermentation temperature not higher than 70 ℃, and adding 1-4 parts of humic acid after fermentation.

When the humic acid organic fertilizer is prepared, the organic fertilizer leavening agent is not particularly limited, and common organic fertilizer leavening agents can be used.

In the composting fermentation process, if the fermentation temperature exceeds 70 ℃, the temperature can be reduced by turning the pile.

The obtained humic acid organic fertilizer can be directly used. In consideration of convenience in use, it may be applied after being granulated and dried.

Examples

The present invention is further described below by way of specific examples, which are merely exemplary and do not limit the scope of the present invention in any way.

Example 1

Example 1

Drying the pollution-free black soil taken from the test field, rolling, naturally drying, sterilizing and sieving by a 100-mesh sieve. Spraying the solution with 200mg/kg of soil. Aging and standing for one week, naturally air drying, pulverizing, sieving with 100 mesh sieve, and simulating contaminated soil sample.

The ramie is planted in the red soil for 130 days, and 200mg/L of citric acid aqueous solution is sprayed every week. After 130 days, the hemp stalks were cut. Washing with deionized water, soaking in 0.01M dilute hydrochloric acid for 1 hr, oven drying at 70.0 deg.C, and pulverizing into 2mm granules. And pyrolyzing the crushed particles in a tubular muffle furnace at 700 ℃ for 100 minutes to prepare the bulk phase zero-valent iron-loaded biochar material.

In XRD of the bulk phase loaded zero-valent iron biochar material, diffraction peaks of 44.8 degrees, 65.1 degrees, 82.2 degrees (zero-valent iron) and diffraction peaks of 43.1 degrees, 50.4 degrees, 73.9 degrees (iron-carbon compound CFe15.1) are found. TEM of bulk phase loaded zero-valent iron modified biochar materials revealed that nano zero-valent iron particles were dispersedly embedded in the biochar bulk phase. XPS of bulk zero-valent iron-loaded biochar material revealed that the zero-valent iron content at the surface, at the depth of 40nm and at the depth of 80nm was 1.41%, 9.02% and 18.35, respectively.

Example 2

The bulk phase zero-valent iron-loaded biochar material obtained in example 1 was uniformly applied in an amount of 60mg/kg to a simulated contaminated soil sample, and left to age naturally.

After 3 days, 1X 10⁸CFU/ml Bacillus subtilis and 1X 10⁸Mixing CFU/ml bacillus licheniformis at a volume ratio of 3:2 to obtain a microorganism for remediation, inoculating the microorganism into a simulated polluted soil sample at an amount of 50mg/kg, placing the sample in a phytotron, and supplementing water with deionized water every other day to maintain soil humidity.

After 3 weeks, the concentration of the dichloro-diphenyl-trichloroethane was 1.09mg/kg, and after 50 days, the concentration of the dichloro-diphenyl-trichloroethane was 0.03 mg/kg.

Example 3

The bulk phase zero-valent iron-loaded biochar material obtained in example 1 was uniformly applied in an amount of 60mg/kg to a simulated contaminated soil sample, and left to age naturally.

After 3 days, 1X 10⁸CFU/ml Bacillus subtilis, 1X 10⁸CFU/ml Bacillus licheniformis and 1X 10⁸The CFU/ml lactobacillus is mixed according to the volume ratio of 3:2:1 to obtain the microorganism for repairing. The microorganisms are inoculated into a simulated polluted soil sample in an amount of 50mg/kg, the sample is placed in an artificial climate incubator, and deionized water is used for supplementing water every other day to maintain the soil humidity.

After 3 weeks, the concentration of the dichloro-diphenyl-trichloroethane was 0.94mg/kg, and after 50 days, the concentration of the dichloro-diphenyl-trichloroethane was 0.02 mg/kg.

Example 4

The bulk phase zero-valent iron-loaded biochar material obtained in example 1 was uniformly applied to a simulated contaminated soil sample in an amount of 45mg/kg soil, and simultaneously 0.001mg/ml potassium persulfate solution was sprayed in an amount of 20mg/kg soil, and was naturally left to age.

After 10 days, 1X 10⁸CFU/ml Bacillus subtilis, 1X 10⁸CFU/ml Bacillus licheniformis and 1X 10⁸The CFU/ml lactobacillus is mixed according to the volume ratio of 3:2:1 to obtain the microorganism for repairing. The microorganisms are inoculated into a simulated polluted soil sample in an amount of 50mg/kg, the sample is placed in an artificial climate incubator, and deionized water is used for supplementing water every other day to maintain the soil humidity.

After 1 week, the concentration of the dichloro-diphenyl-trichloroethane was 0.64mg/kg, and after 20 days, the concentration of the dichloro-diphenyl-trichloroethane was 0.02 mg/kg.

Example 5

Cutting crop straws into 2 cm fragments, uniformly mixing 60kg of animal wastes, 15kg of straw particles and 10kg of vinasse, spraying 100ml of Rw organic fertilizer fermentation microbial inoculum (Nippon Biotechnology development Co., Ltd., Heling wall), stacking and fermenting for 10 days at the fermentation temperature of not more than 70 ℃, and adding 1kg of humic acid (Jinan Aoka chemical Co., Ltd.) after fermentation to obtain the humic acid organic fertilizer.

The bulk phase zero-valent iron-loaded biochar material obtained in example 1 was uniformly applied to a simulated contaminated soil sample in an amount of 50mg/kg, and left to age naturally.

After 3 days, 1X 10⁸CFU/ml Bacillus subtilis, 1X 10⁸CFU/ml Bacillus licheniformis and 1X 10⁸The CFU/ml lactobacillus is mixed according to the volume ratio of 3:2:1 to obtain the microorganism for repairing. The microorganisms are inoculated into a simulated polluted soil sample in an amount of 50mg/kg, the sample is placed in an artificial climate incubator, and deionized water is used for supplementing water every other day to maintain the soil humidity.

After 3 weeks, the concentration of the dichloro-diphenyl-trichloroethane was 0.96mg/kg, and after 50 days, the concentration of the dichloro-diphenyl-trichloroethane was 0.02 mg/kg. Applying humic acid organic fertilizer in the amount of 20mg/kg soil, the concentration of the dichlorodiphenyl trichloroethane is 0.016mg/kg after 20 days, and the volume weight of the soil is 0.6052g/cm³The organic content is 24.213 g/kg.

The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention.