CN107512977B - A kind of preparation method and application of EM nano-biochar-based soil conditioner - Google Patents

Abstract

The invention discloses a preparation method and application of an EM nano-biochar-based soil conditioner. First, straw powder, nano-manganese oxide and kaolin are mixed to prepare a modified nano-straw biochar carrier under high temperature conditions. Then, the activated EM calcium solution was immobilized on the modified nano-straw biochar carrier to make EM nano-biochar balls for soil conditioning. The EM nano-biochar-based soil conditioner has a simple preparation process, has the functions of nitrogen fixation, phosphorus solution, potassium solution, water retention, secretion of antibacterial substances, etc., and significantly improves soil moisture and N, P, K, Ca, Fe in the soil. The effectiveness of other elements can reduce the occurrence of crop diseases, and has a strong adsorption capacity for heavy metals, pesticide residues, etc., and can significantly improve the soil structure.

Description

A kind of preparation method and application of EM nano-biochar-based soil conditioner

technical field

The invention relates to the technical field of soil improvement and soil environment repair, in particular to a preparation method and application of an EM nano-biochar-based soil conditioner.

Background technique

Biochar is a class of highly aromatic solids produced by pyrolytic carbonization of plant biomass in the presence of complete or partial oxygen deficiency. Biochar is highly stable, has strong adsorption capacity, can maintain soil moisture and nutrients, and is a good soil conditioner. Common biochars include straw charcoal, bamboo charcoal, rice husk charcoal, etc. The straw carbon in biochar is rich in raw materials, low in price, relatively simple in production process, and has broad prospects for development and utilization. According to statistics, the annual output of straw in the world is about 2.9 billion tons. Straw biochar replaces wood-fired charcoal, which is conducive to protecting forest resources, maintaining ecological balance, and playing an important role in global climate change, carbon cycle and environmental issues. In recent years, the non-point source pollution caused by the extensive use of chemical fertilizers is forming a three-dimensional pollution pattern from soil, water, organisms to the atmosphere (soil acidification, heavy metal pollution, eutrophication of water, intensified greenhouse effect, etc.), which seriously affects agricultural development and ecological environment. balance. How to improve the utilization efficiency of chemical fertilizers and reduce the environmental pollution caused by the large-scale use of chemical fertilizers has become an urgent problem to be solved in the sustainable and coordinated development of China's economy, ecology and environment.

At present, charcoal-based fertilizers such as bamboo charcoal bio-organic fertilizer, bamboo charcoal soil conditioner, bamboo charcoal compound microbial fertilizer, carbon energy bio-bacterial fertilizer, liquid carbon fertilizer and other products are slowly circulating in the market, and many farmers have also begun to pay attention to supplementing the soil with charcoal (carbon). The types of products are also gradually diversifying, but the ultimate goal is to supplement the carbon elements needed by plants, improve the aggregate structure of the soil, and improve the soil water and fertilizer retention capacity and fertilizer utilization rate. Therefore, it is particularly important and urgent to seek environmentally friendly and low-cost materials and prepare conditioners for soil improvement, which is of great significance for preventing and controlling agricultural non-point source pollution and protecting soil ecological environment and food safety.

At present, the most widely used soil conditioners are activated carbon, bamboo charcoal, grass (peat) charcoal, slag, powder ash, etc. Although these materials have their own characteristics, there are some problems such as difficulty in microbial film forming, low porosity, high use cost, and the existence of Disadvantages such as secondary pollution. Some studies have shown that the effect of conditioners on immobilizing microorganisms and adsorbing pollutants in the process of soil conditioning is closely related to the performance of the conditioners used. And the microbial activity is stronger. The adsorption capacity of the conditioner to microorganisms and pollutants depends on its specific surface area, void structure and surface characteristics. To sum up, it is very important to choose suitable materials and methods in the preparation of soil conditioners. The present invention uses biochar made from waste straws as the main raw material, prepares conditioners by modifying and immobilizing composite microorganisms and applies them to soil, so as to improve soil and absorb pollutants such as heavy metals and pesticides in soil, and reduce damage to benefit, comprehensive utilization, and the purpose of reducing environmental pollution.

SUMMARY OF THE INVENTION

Purpose of the invention: Aiming at the problems of soil obstacles and environmental pollution caused by the extensive use of chemical fertilizers and pesticides, using straw biochar as the main raw material, by modifying and immobilizing compound microorganisms to prepare conditioners and applying them in soil repair, the improvement is achieved. The purpose of soil and passivation of heavy metals, pesticides and other pollutants in soil. The product obtained by the invention has the functions of nitrogen fixation, phosphorus solution, potassium solution, water retention, secretion of antibacterial substances, etc., which can significantly improve soil moisture and the effectiveness of N, P, K, Ca, Fe and other elements in the soil, and can reduce the physiological effects of crops. sexually transmitted diseases.

Technical scheme: in order to achieve the above technical purpose, the present invention provides a preparation method and application of a (0) nanometer biochar-based soil conditioner, comprising the following steps:

(1) Mix the EM stock solution, honey, solid calcium sulfate and water (preferably distilled water) in a mass percentage of 5-8%: 6-10%: 4-8%: 74-85%, and transfer it into a reaction flask , under airtight conditions, put it into a constant temperature incubator to ferment for 5 to 7 days, set the fermentation temperature to 30 to 35 °C, and the shaker rotation speed to 120 to 150 r/min, and filter to obtain EM active calcium solution; EM stock solution contains photosynthetic Compound microorganisms such as bacteria, bifidobacteria, lactic acid bacteria, yeast, actinomycetes, etc., have good soil improvement effect, and their rejuvenation liquid contains growth promoting factors, which has a stimulating effect on crop growth; the role of honey is as an energy source in the process of microbial rejuvenation Substances can quickly rejuvenate EM; solid calcium sulfate is partially converted into soluble chelated calcium during the fermentation process, which can provide essential calcium and sulfur nutrients for crops;

(2) Pulverize the dry straw, pass it through a 2mm sieve, and then prepare it in a stainless steel tank according to the mass percentage of corn straw powder: kaolin binder: nano-iron trioxide = 80-88: 10-6: 10-6 The mixture is compacted, covered and sealed, then placed in a muffle furnace, and cracked at 450 to 550 ° C for 50 to 60 minutes; kaolin is resistant to high temperature, which can provide good cohesion during the material forming process, making it difficult to break;

(3) the mixture obtained in step (2) is taken out and put into a vacuum dryer, cooled to room temperature, to obtain nano biomass carbon, which is ground finely through a 100-mesh sieve, and then the nano biomass carbon and the EM active calcium solution are subjected to mass The percentage of 90-95%: 5-10% is mixed to obtain EM nano-biochar-based soil conditioner material. EM active calcium solution can extract a large number of beneficial bacteria and active substances, inhibit the growth of harmful microorganisms in the soil, and through microbial transformation in the soil, nitrogen fixation, phosphorus solution, potassium solution, and soil nutrients are released.

Preferably, in step (1), the EM stock solution contains composite microorganisms such as lactic acid bacteria, yeast, photosynthetic bacteria, bifidobacteria, the number of viable bacteria is not less than 100 million/ml, the pH is not less than 3.8, and the color is yellow Brown, translucent liquid, with a strong sour or sour smell.

In step (1), the described solid calcium sulfate is analytically pure and passes through a 100-mesh sieve.

Preferably, the honey is a honey product purchased in a supermarket.

In step (2), the binder kaolin is preferably a chemical product of over 100 meshes, and the particle size of the nanometer ferric oxide is 20-40 nm. Nano-Fe2O3 has the characteristics of huge specific surface area and porosity, good biocompatibility, and large adsorption capacity, which can effectively improve the adsorption, fixation and immobilization of biochar. The porosity and specific surface area of the biochar modified with EM active calcium and nano-Fe2O3 increased, the porosity was good, and the adsorption capacity for water, nutrients and heavy metals was stronger, and the microorganisms were more likely to form films.

Specifically, in step (2), the straw is any one of corn straw, rice straw and tobacco straw.

The (0) nanometer biochar-based soil conditioner obtained by the above-mentioned preparation method is also within the protection scope of the present invention.

The present invention further proposes the use of the above-mentioned EM nano-biochar-based soil conditioner in the preparation of soil water-saving, weight-loss and synergy or facility obstacle soil to absorb heavy metals, pesticide residues and the like.

When used as a soil conditioner, the (0) nanometer biochar-based material is prepared into granules by a molding machine, and then placed in the obstacle soil to be acted upon.

Preferably, the (0) nanometer biochar-based material is prepared into granules by using an intelligent mode pelletizer, and the diameter of the particles is controlled at 5-6 mm. However, the preparation of biomass materials into other shapes is also within the protection scope of the present invention .

In application, the dosage of the (0) nano-biochar-based soil conditioner is 10-15 g/m ² .

Beneficial effect: Compared with the prior art, the present invention has the following advantages:

(1) The present invention selects crop straw and kaolin to be mixed under high temperature and airtight conditions to prepare straw biomass charcoal as a microbial carrier, and uses nano-iron trioxide (specific surface area 1000-1500 m ² /g) to chemically conduct chemical treatment on straw biomass charcoal. Modification, the specific surface area of straw biochar is significantly increased, and the EM active calcium solution is fixed on the modified nano-biochar base, which can increase the number of attached microorganisms and their activity, and improve their adaptability to the environment;

(2) The preparation method of the present invention is simple in process, utilizes resource-rich plant straws and has low production cost, has the ability to rapidly absorb and passivate soil heavy metals and pesticide residues, and release nutrients such as slow-acting nitrogen, phosphorus, and potassium in the soil. It has the advantages of improving soil enzyme activity and soil water availability;

(3) In the production process of biomass charcoal, adding nano ferric oxide to chemically modify the biomass charcoal, so that it has better biocompatibility, and the cell adsorption capacity can reach 500-700mg/g;

(4) Increase soil carbon sinks, rapidly transform soil structure, enhance soil permeability, improve crop root activity, promote photosynthesis, enhance crop stress resistance, reduce crop pests and diseases, and effectively eliminate the long-term application of chemical fertilizers to agricultural products. Therefore, the pollution-free agricultural products can be realized by eliminating the essential problems such as unscented melons, unsweetened fruits, tasteless vegetables and residual nitrate pollution.

Detailed ways

Reagent source:

The nano-iron trioxide used in the present invention is purchased from Beijing Deke Island Gold Technology Co., Ltd., and the particle size is between 20 and 40 nm. The solid calcium sulfate was purchased from Zhengzhou Xideli Chemical New Material Co., Ltd., the EM stock solution was produced by Amule Environmental Biotechnology (Nanjing) Co., Ltd., the kaolin binder was produced by Zhengzhou Runquan Chemical Products Co., Ltd., and the honey was produced in supermarkets. Purchased honey products. The present invention will be described in detail below through specific examples.

Example 1

Mix the EM stock solution, honey, solid calcium sulfate and distilled water according to the mass percentage of 6%: 6%: 6%: 82%, transfer it into a reaction bottle, and put it into a constant temperature incubator for fermentation for 6 days under airtight conditions , set the fermentation temperature to 37°C, the shaker rotation speed to 150r/min, and filter to obtain the EM active calcium solution; then pulverize the dried corn stalks, pass through a 2mm sieve, and press the corn stalk powder in a stainless steel tank: Kaolin binder: The mass percentage of nano-iron trioxide = 85:7:8 is uniformly mixed, compacted, covered and sealed, placed in a muffle furnace, and cracked at 550 ° C for 55 min; then the above mixture is taken out and placed in a vacuum desiccator, cooled At room temperature, the obtained nano-biochar was ground and passed through a 100-mesh sieve, and then in the intelligent mode pelletizing machine, the nano-biochar: EM activated calcium solution = 93%: 7% was formed, and the diameter of the particles was controlled at 5mm. In between, the EM nanobiochar soil conditioner was obtained. The soil conditioning experiment for potted plants was carried out in a plastic greenhouse. The pots used were 28 cm in height, 28 cm in diameter and 0.01 m ³ in volume. The test soils were secondary saline soil (NS, taken from the facility greenhouse of Nanjing Institute of Vegetable Science for 5 years) and coastal saline soil (S, taken from Tiaozi mud reclamation area in Dongtai, Jiangsu). See Table 1 for properties. The above soil was naturally air-dried and ground through a 5mm sieve, and then placed in pots, each pot containing 7.0 kg of soil. Three treatments were set: (1) control; (2) bio-organic fertilizer (30% organic matter, 5% total nitrogen, 1% total P+total K), which was produced by Amule Environmental Biotechnology (Nanjing) Co., Ltd. EM Bokaxi and the organic fertilizer produced by Nanjing Ningliang Biological Engineering Co., Ltd. are obtained after secondary fermentation; (3) the soil conditioner of the present invention; the application amount of treatment (2) and treatment (3) is evenly 5g/pot. Each treatment was repeated 3 times, randomly arranged. Bio-organic fertilizers and soil conditioners were thoroughly mixed with the soil before potting. The soil water content in the pots was maintained for 30 days, and the relevant indicators were monitored after 5 days.

As shown in table 2.

Table 1 Physical and chemical properties of the tested soils

Table 2 Water and fertilizer retention effects and buffering properties of acids and salts for each treatment

As can be seen from Table 2, the EM nano-biochar-based soil conditioner of the present invention fixes nitrogen, dissolves phosphorus, and dissolves potassium, and the effect of releasing soil nutrients and retaining water is significantly better than that of EM bio-organic fertilizer, and has better pH and salinity. The buffering effect indicates that the EM nanobiochar-based soil conditioner has a good conditioning effect on the barrier soil and saline-alkali soil.

Example 2

Mix the EM stock solution, honey, solid fluid calcium and distilled water according to the mass percentage of 5%: 7%: 8%: 80%, transfer it into a reaction bottle, and put it into a constant temperature incubator to ferment 7 day, set the fermentation temperature to 35°C and the shaker rotation speed to 150r/min, and filter to obtain the EM active liquid; then pulverize the dried corn stalks, pass through a 2mm sieve, and press the corn stalk powder: kaolin binder in a stainless steel tank: Nano-iron trioxide = 82:8:10 mass percentage is uniformly mixed, compacted, covered and sealed, placed in a muffle furnace, and cracked at 520 ° C for 60 min; then the above mixture is taken out and placed in a vacuum desiccator, cooled At room temperature, the obtained nano-biochar was ground and passed through a 100-mesh sieve, and then in the intelligent mode pelletizing machine, the nano-biochar: EM activated calcium solution = 92%: 8% was formed, and the diameter of the particles was controlled at 5mm. In between, the EM nanobiochar soil conditioner was obtained. The soil contaminated with heavy metals for testing was collected from Xuzhou and Yixing mining areas in Jiangsu, respectively. The soil was naturally air-dried and ground through a 5mm sieve, and then filled into pots with 5.0 kg of soil per pot. Set (1) control; (2) bio-organic fertilizer (30% of organic matter, 5% of total nitrogen, 1% of total P+total K), which is EM bokase produced by Amule Environmental Biotechnology (Nanjing) Co., Ltd. After secondary fermentation with the organic fertilizer produced by Nanjing Ningliang Bioengineering Co., Ltd., three treatments of (3) the soil conditioner of the present invention are obtained, and the application amount of the treatments (2) and (3) is uniformly 5g/pot. Bio-organic fertilizers and soil conditioners were thoroughly mixed with the soil before potting. The soil moisture content in the pots was maintained for 30 days. After 5 days, the soil was borrowed with EDTA to monitor the available heavy metal indicators. The results are shown in Table 3.

The amount of heavy metals (mg/kg) extracted by the EDTA of each treatment in Table 3

As can be seen from Table 3, the EM nano-biochar-based soil conditioner of the present invention has a significantly better passivation effect on heavy metals in soil than bio-organic fertilizers.

The above monitoring data show that the EM nano-biochar-based soil conditioner of the present invention has good effects in activating nutrient elements in soil, retaining water, buffering soil pH and passivating soil heavy metals.

The above are only typical embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. within.

Claims (9)

1. A preparation method of an EM nano biochar-based soil conditioner is characterized by comprising the following steps:

(1) mixing 5-8% of EM stock solution, honey, solid calcium sulfate and water: 6-10%: 4-8%: mixing 74-85% by mass, transferring into a reaction bottle, fermenting in a constant-temperature incubator for 5-7 days under a closed condition, setting the fermentation temperature at 30-35 ℃ and the rotating speed of a shaking table at 120-150 r/min, and filtering to obtain EM active calcium liquid;

(2) crushing the dried straws, sieving the crushed straws by a 2mm sieve, and then putting the crushed straws in a stainless steel tank according to the weight ratio of the biological straw powder: adhesive: 80-88% of nano ferric oxide: 10-6: 10-6 percent of the mixture by mass is compacted, sealed by a cover, and then put into a muffle furnace to be cracked for 50-60 min at 450-550 ℃; the adhesive is kaolin which is sieved by a 100-mesh sieve before use, and the particle size of the nano ferric oxide is 20-40 nm;

(3) taking out the mixture obtained in the step (2), putting the mixture into a vacuum drier, cooling to room temperature to obtain nano biomass charcoal, grinding the nano biomass charcoal and passing through a 100-mesh sieve, and then mixing the nano biomass charcoal and EM activated calcium liquid according to the mass percentage of 90-95%: 5-10% of the EM nano biochar-based soil conditioner material is obtained by mixing.

2. The method for preparing the EM nano biochar-based soil conditioner according to claim 1, wherein in the step (1), the EM stock solution is EM stock solution produced by environment-friendly harmonious biotechnology (Nanjing) Limited, contains composite microorganisms of lactic acid bacteria, saccharomycetes, photosynthetic bacteria, bifidobacteria and actinomycetes, has the viable count of not less than 1 hundred million/ml, has the pH of not less than 3.8, and is yellow brown and semitransparent liquid.

3. The preparation method of the EM nano biochar-based soil conditioner as claimed in claim 1, wherein in the step (1), the solid calcium sulfate is analytically pure and is sieved by a 100-mesh sieve before use.

4. The preparation method of the EM nano biochar-based soil conditioner as claimed in claim 1, wherein in the step (2), the straw is any one of rice straw, corn straw and tobacco straw.

5. The EM nano biochar-based soil conditioner obtained by the preparation method of any one of claims 1 to 4.

6. Use of the EM nanocarbon based soil conditioner of claim 5 for soil water saving weight loss enhancement or facility obstacle soil heavy metal uptake, buffering soil pH and pesticide residue.

7. The use of claim 6, wherein when the EM nano biochar-based soil conditioner is used for water saving, weight losing and synergism of soil or heavy metal and pesticide residue absorption of facility obstacle soil, the EM nano biochar-based soil conditioner is prepared into granules by a forming machine and then is put into the soil to be acted.

8. The use of claim 7, wherein the EM nano biochar-based soil conditioner is prepared into granules by using an intelligent mode pelletizer, and the diameter of the granules is controlled to be 5-6 mm.

9. The use according to claim 7, wherein the EM nano biochar-based soil conditioner is used in an amount of 10-15 g/m²。