Repairing agent prepared by taking biomass as raw material, preparation method of repairing agent and application of repairing agent in farmland repairing

Abstract

The invention relates to the technical field of farmland remediation, and discloses a remediation agent prepared from biomass as a raw material, a preparation method of the remediation agent and application of the remediation agent in farmland remediation. Comprising biomass charcoal, and TiO2, LDH and MOF loaded in the biomass charcoal. According to the carbon material repairing agent provided by the invention, TiO2, LDH and MOF are loaded by utilizing porous channels of the carbon material, the adsorbability to heavy metal ions is enhanced by utilizing loading of LDH, a complex can be formed by utilizing loading of TiO2, and the utilization rate of biomass charcoal to light is improved, so that the adsorption capacity to heavy metal elements is improved, and the effect of removing heavy metal is further achieved. By loading the substances in the porous carbon in situ, the agglomeration phenomenon can be effectively avoided. The MOF is loaded in the biochar material, so that a larger contact area and adsorption sites are provided.

Description

Technical Field

[0001] The present invention relates to the technical field of farmland restoration, and in particular to a restoration agent prepared using biomass as a raw material, a preparation method thereof, and an application of the restoration agent in restoring farmland. Background Art

[0002] At present, the situation of agricultural soil pollution is severe and has become an important bottleneck restricting the sustainable development of agriculture. The main sources of agricultural soil pollution include industrial emissions, agricultural production activities, urban life pollution, etc. These sources will seriously affect the growth and development of crops and yields, and will also reduce the quality of agricultural products and cause potential food safety. More seriously, soil pollutants will also enrich and threaten human health through the food chain and multiple pathways. At the same time, there are also problems of destroying the structure of microbial communities, changing the diversity of microbial communities, and destroying the structure of the food web. Based on this, the remediation of soil pollution is imminent. Summary of the invention

[0003] Technical problems solved by the present invention:

[0004] The invention is used to provide a farmland soil repair agent.

[0005] The technical solution adopted by the present invention is:

[0006] In view of the above-mentioned technical problems, the object of the present invention is to provide a repair agent prepared using biomass as raw material, a preparation method thereof, and an application thereof in repairing farmland.

[0007] Based on this, the specific implementation plan is:

[0008] First, the present invention provides a repair agent prepared using biomass as raw material, including biochar and TiO2, LDH and MOF loaded inside the biochar.

[0009] According to some preferred embodiments, the biomass raw material includes at least one of bamboo chopsticks, rice husks, straw, rice straw, bagasse, wood blocks, and grass leaves.

[0010] According to some preferred embodiments, the LDH is nickel-iron double hydroxide.

[0011] Second, the present invention provides a method for preparing the aforementioned repair agent prepared using biomass as raw material, comprising the following steps:

[0012] S1 biomass is heat treated to obtain biochar; heat treatment: 350-550°C, 1-3h. More preferably, 550°C, 2h. After heat treatment, the product is naturally cooled to room temperature, and then washed alternately with deionized water and ethanol to obtain biochar.

[0013] S2 modifies the biochar by cyanide to obtain modified cyanide biochar; specifically: the cleaned biochar is placed in the treatment liquid for oscillation and blending for 10 to 30 minutes, then acrylonitrile is added, and the oscillation reaction is continued for 3 to 6 hours, and then filtered, deionized, washed, and dried to obtain the treated product. The treatment liquid includes alkali, urea, and water, and the mass ratio of the three is 2 to 5:12 to 20:100, and the alkali is sodium hydroxide. The biochar accounts for 1 to 3% of the mass of the treatment liquid, and the ratio of acrylonitrile to biochar is 0.8 to 1.6 mL / g.

[0014] S3 modified cyano biomass carbon loaded MOF to obtain a first carrier; the MOF material precursor liquid includes terephthalic acid, FeCl3·6H2O and DMF.

[0015] S4 The first support body is loaded with TiO2 to obtain a second support body; the first support body is immersed in deionized water, dehydrated, and then dispersed in a tetrabutyl titanate ethanol solution, stirred and blended at 200r / min for 3h, filtered, and then washed alternately with water and ethanol, and dried to obtain a support body loaded with TiO2. The concentration of tetrabutyl titanate is 25% (V / V).

[0016] S5 The second carrier is loaded with LDH to obtain a repair agent. The second carrier is dispersed in the second precursor liquid, and after being evenly dispersed, it is placed in a hydrothermal reactor and reacted at 100-130°C for 6-12 hours. After the reaction is completed, it is naturally cooled to room temperature, and then filtered, washed with deionized water, and dried to obtain a repair agent. The mass ratio of Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea, deionized water, and the second carrier in the second precursor liquid is 0.98:0.44:12:30:0.3-0.5.

[0017] Third, the present invention provides an application of the above-mentioned repair agent in repairing farmland.

[0018] The technical mechanism and beneficial effects adopted by the present invention are as follows:

[0019] (1) The carbon material repair agent provided by the present invention utilizes the fact that biomass is widely available, cheap and easy to obtain, and contains rich active groups. It utilizes the porous structure and excellent adsorption capacity formed by it, so that it has a strong complexing ability with heavy metal ions, thereby reducing the mobility and bioavailability of heavy metal ions in the soil through fixation, thereby reducing the harm of heavy metals to crops.

[0020] (2) The carbon material repair agent provided by the present invention utilizes the porous channels of the carbon material to load TiO2, LDH and MOF. The LDH loading enhances the adsorption of heavy metal ions. The TiO2 loading can form a complex, thereby improving the utilization rate of light by the biochar, thereby improving the adsorption capacity of heavy metal elements, and achieving the effect of removing heavy metals. By in-situ loading of the aforementioned substances in the porous carbon, the phenomenon of agglomeration can be effectively avoided. By loading MOF in the biochar material, a larger contact area and adsorption sites are provided.

[0021] (3) Improving biochar with cyanide can not only improve the physical adsorption capacity, but also the presence of cyanide can form stable coordination bonds with metal ions in MOF materials, thereby improving the dispersibility of MOF materials in biochar and the overall structural stability. The strong interaction between cyanide and MOFs and the strong skeleton of porous carbon itself together give the composite material higher mechanical strength. The presence of MOFs can also serve as a "support point", making the carbon material less likely to deform or break when subjected to force. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0023] Example 1

[0024] This embodiment provides a method for preparing a repair agent:

[0025] (1) Sugarcane bagasse was used as the biomass raw material. After crushing, it was placed in a polytetrafluoroethylene-lined reactor and heat treated at 550°C for 2 h. After naturally cooling to room temperature, the heat-treated product was collected and then washed alternately with deionized water and ethanol.

[0026] (2) The cleaned heat-treated product is placed in a treatment solution and oscillated for 20 minutes, then acrylonitrile is added, and the oscillation reaction is continued for 5 hours, and then filtered, deionized, washed, and dried to obtain a treated product. The treatment solution includes alkali, urea, and water, and the mass ratio of the three is 3:115:100, and the alkali is sodium hydroxide. The heat-treated product accounts for 2% of the mass of the treatment solution, and the ratio of acrylonitrile to the heat-treated product is 1.0 mL / g.

[0027] (3) The treated product is blended with the first precursor liquid, and subjected to ultrasonic treatment, and then transferred to a high-pressure reactor, reacted at 100°C for 15 hours, cooled to room temperature after the reaction, and washed alternately with ethanol and water to obtain the first carrier. The first precursor liquid includes terephthalic acid and FeCl3·6H2O. Specifically, 6mmol of terephthalic acid and 8.6mmol of FeCl3·6H2O are dissolved in 150mL of DMF, and after uniform stirring and mixing, 15mL of 1mol / LNaOH solution is added dropwise, and the MOF precursor liquid is obtained after stirring.

[0028] (4) After the first support is immersed in deionized water, it is dehydrated and then dispersed in a tetrabutyl titanate solution (the solvent is ethanol), stirred and blended at 200 r / min for 2 to 5 hours, filtered, and then washed alternately with water and ethanol, and dried to obtain a support loaded with TiO2. The concentration of tetrabutyl titanate is 25% (V / V).

[0029] (4) The support body loaded with TiO2 is dispersed in the second precursor liquid, and after being evenly dispersed, it is placed in a hydrothermal reactor and reacted at 120°C for 10 hours. After the reaction is completed, it is naturally cooled to room temperature, and then filtered, washed with deionized water, and dried to obtain a repair agent. The second precursor liquid contains a mixture of Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea, and deionized water. The mass ratio of Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea, deionized water, and the support body loaded with TiO2 is 0.98:0.44:12:30:0.5.

[0030] Comparative Example 1

[0031] The difference between this comparative example and Example 1 is that the heat-treated product is loaded with TiO2.

[0032] Comparative Example 2

[0033] The difference between this comparative example and Example 1 is that the support body loaded with TiO2 is directly used as the repairing agent.

[0034] Comparative Example 3

[0035] The difference between this comparative example and Example 1 is that the treated material is loaded with TiO2.

[0036] Test example

[0037] The repair agents of Example 1 and Comparative Examples 1-3 were used as samples for testing and BET testing. The results are shown in Table 1.

[0038] Table 1

[0039] sample <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Total pore volume (cm 3 / g)]]> Average pore size (nm) Example 1 6.17 0.020 11.43 Comparative Example 1 4.73 0.012 10.34 Comparative Example 2 3.87 0.010 10.01 Comparative Example 3 5.74 0.015 10.68

[0040] The repair agent prepared in Example 1 and Comparative Examples 1-3 was used as a sample for testing. The repair agent (3wt%) was added to the arsenic-contaminated farmland soil and cultured for 60 days at 25°C and a water content of 70-80%. The arsenic content was collected separately (various forms of arsenic in the soil were extracted according to the continuous extraction method, including non-specific adsorption arsenic EXE, specific adsorption arsenic CA, bound arsenic Fe-Mn+OM, and residual arsenic RES), and the results are shown in Table 2.

[0041] Table 2

[0042]

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A repair agent prepared from biomass as raw material, characterized in that: It includes biochar and TiO2, LDH and MOF loaded inside the biochar.

2. The repairing agent prepared from biomass as raw material according to claim 1, characterized in that: The biomass raw material includes at least one of bamboo chopsticks, rice husks, straw, rice straw, bagasse, wood blocks, and grass leaves.

3. The repairing agent prepared from biomass as raw material according to claim 1, characterized in that: LDH is nickel-iron double hydroxide.

4. A method for preparing a repairing agent using biomass as raw material as claimed in any one of claims 1 to 3, characterized in that: The steps include: S1 biomass is thermally treated to obtain biochar; S2 modifies the biochar by cyano to obtain modified cyano biochar; S3 modified cyano biomass carbon loaded with MOF to obtain a first support; S4 The first support body loads TiO2 to obtain a second support body; S5 The second carrier loads LDH to obtain a repair agent.

5. The method for preparing a repairing agent using biomass as raw material according to claim 4, characterized in that: Heat treatment: 350-550°C, 1-3h.

6. The method for preparing a repairing agent using biomass as raw material according to claim 4, characterized in that: The MOF material precursor liquid includes terephthalic acid, FeCl3·6H2O and DMF.

7. The method for preparing a repairing agent using biomass as raw material according to claim 4, characterized in that: The LDH material precursor liquid includes Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea and deionized water.

8. Use of the repair agent as claimed in any one of claims 1 to 3, or the repair agent obtained by the preparation method as claimed in any one of claims 4 to 7 in repairing farmland.

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