阅读说明：本技术 市政污泥基生物炭改良营养土及其生产方法 (Municipal sludge-based biochar improved nutrient soil and production method thereof ) 是由 孙东晓 宋芊 董志强 刘学明 王轶喆 张吉琛 杨蒙岭 谭咏 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种市政污泥基生物炭改良营养土及其生产方法,该方法依次包含如下步骤：将市政污泥风干后粉碎；将粉碎后的市政污泥进行辊压,形成片状颗粒,以便于后续的炭化；将制备的片状颗粒进行炭化,制备得到市政污泥基生物炭；将制备的市政污泥基生物炭与其他原料进行搅拌混合,得到营养土半成品；其中,其他原料包含膨润土、蛭石、凹凸棒、高岭石和水,质量配比为,市政污泥基生物炭∶膨润土∶蛭石∶凹凸棒∶高岭石∶水＝(5-25)∶(5-20)∶(5-20)∶(5-20)∶(5-20)∶(10-20)；灭菌并干燥。本发明制备的营养土富含植物所需的多种营养元素,为植物生长提供基本的肥力；该营养土质地疏松,具有更大的比表面积,保肥保墒能力大。(The invention discloses municipal sludge-based biochar improved nutrient soil and a production method thereof, and the method sequentially comprises the following steps: drying and crushing municipal sludge; rolling the crushed municipal sludge to form flaky particles so as to facilitate subsequent carbonization; carbonizing the prepared flaky particles to prepare municipal sludge-based biochar; stirring and mixing the prepared municipal sludge-based biochar with other raw materials to obtain a semi-finished product of the nutrient soil; wherein the other raw materials comprise bentonite, vermiculite, attapulgite, kaolinite and water in a mass ratio of (5-25) municipal sludge-based biochar to bentonite to vermiculite to attapulgite to kaolinite to water to (5-20) to (10-20); sterilizing and drying. The nutrient soil prepared by the invention is rich in various nutrient elements required by plants, and provides basic fertility for plant growth; the nutrient soil has loose texture, larger specific surface area and large capacity of preserving fertilizer and moisture.)

1. The production method of the municipal sludge-based biochar modified nutrient soil is characterized by sequentially comprising the following steps:

s1, drying the municipal sludge in the air and then crushing the sludge;

s2, rolling the crushed municipal sludge to form flaky particles so as to facilitate subsequent carbonization;

s3, carbonizing the flaky particles prepared in the step S2 to prepare municipal sludge-based biochar;

s4, stirring and mixing the municipal sludge-based biochar prepared in the step S3 and other raw materials to obtain a semi-finished product of the nutrient soil; wherein the other raw materials comprise bentonite, vermiculite, attapulgite, kaolinite and water in a mass ratio of (5-25) municipal sludge-based biochar to bentonite to vermiculite to attapulgite to kaolinite to water to (5-20) to (10-20);

s5, sterilizing and drying.

2. The method for producing the municipal sludge-based biochar modified nutrient soil as claimed in claim 1, wherein the method comprises the following steps: the carbonization in the step S3 is carried out at the temperature of 300 ℃ and 500 ℃ for 1-2 h.

3. The method for producing the municipal sludge-based biochar modified nutrient soil as claimed in claim 1, wherein the method comprises the following steps: the granularity of the municipal sludge-based biochar, bentonite, vermiculite, attapulgite and kaolinite in the step S4 is less than 2 mm.

4. The method for producing the municipal sludge-based biochar modified nutrient soil as claimed in claim 1, wherein the method comprises the following steps: the other raw materials in the step S4 further include at least one of a nitrogen fertilizer, a phosphate fertilizer, and a potassium fertilizer.

5. The method for producing the municipal sludge-based biochar modified nutrient soil as claimed in claim 1, wherein the method comprises the following steps: and the sterilization and drying method in the step S5 is that the semi-finished product of the nutrient soil is placed in a sterilizing furnace for sterilization and drying, the temperature is controlled to be 40-60 ℃, the time is 0.5-2h, and the water content is reduced to be within 10 percent.

6. The method for producing the municipal sludge-based biochar-modified nutrient soil as claimed in claim 1, wherein when the yield of the municipal sludge-based biochar-modified nutrient soil is less than 20kg, the sterilizing and drying method in step S5 comprises:

s5.1, controlling the temperature of the semi-finished product of the nutrient soil uniformly mixed in the step S4 to be 100-;

and S5.2, adding a certain amount of water into the product sterilized in the step S5.1, uniformly mixing the product and the water again, and then drying the product at a low temperature.

7. A municipal sludge-based biochar-modified nutrient soil produced by the production method according to any one of claims 1 to 6, wherein: the municipal sludge-based biochar modified nutrient soil is loose in structure, irregular in shape and rough in surface.

Technical Field

The invention relates to the field of nutrient soil, in particular to municipal sludge-based biochar modified nutrient soil and a production method thereof.

Background

Most of nutrient soil in the market is simple mixture of kaolinite, attapulgite and various compound fertilizers, and the problems of hardening, fertility reduction and the like can be caused after long-time use, so that the nutrient in the nutrient soil can not be fully utilized by plants, the resource waste is caused, and even further pollution can be caused. Therefore, the advantages of the nutrient soil can not be fully exerted in the cultivation process of bonsais and seedlings, and even the plants are caused physiological pathological changes due to nutrient deficiency.

The biochar is a high-carbon product obtained by pyrolyzing animal and plant remains, animal wastes, sludge and the like at high temperature under the anoxic condition. The biochar has the advantages of looseness, porosity, large specific surface area, more oxygen-containing groups, large cation exchange capacity and the like. The raw materials of the municipal sludge-based biochar are low in price and easy to collect, the problems of sludge pollution and the like can be reduced, the effect of treating wastes with processes of wastes against one another by utilizing sludge resource utilization is achieved, and the municipal sludge-based biochar has a wider application prospect. Municipal sludge of urban sewage plants is a precipitate generated in the sewage treatment process, contains a large amount of microorganisms, organic matters and rich nutrients, does not contain heavy metals relative to industrial sludge, and is more suitable for preparing biochar. At present, raw materials for realizing the resource utilization of solid wastes, particularly nutrient soil formulas using municipal sludge biochar as raw materials, are rarely reported, and the problems in the aspects of preparation of the sludge biochar, preparation of the nutrient soil of the type and the like need to be explored and verified.

Disclosure of Invention

The invention aims to solve the problems of hardening and fertility reduction of the traditional nutrient soil after long-term use, increase the porosity of the nutrient soil and prolong the service life of the nutrient soil.

In order to achieve the aim, the invention provides a production method of municipal sludge-based biochar modified nutrient soil, which sequentially comprises the following steps:

s1, drying the municipal sludge in the air and then crushing the sludge;

s2, rolling the crushed municipal sludge to form flaky particles so as to facilitate subsequent carbonization;

s3, carbonizing the flaky particles prepared in the step S2 to prepare municipal sludge-based biochar;

s4, stirring and mixing the municipal sludge-based biochar prepared in the step S3 and other raw materials to obtain a semi-finished product of the nutrient soil; wherein the other raw materials comprise bentonite, vermiculite, attapulgite, kaolinite and water in a mass ratio of (5-25) municipal sludge-based biochar to bentonite to vermiculite to attapulgite to kaolinite to water to (5-20) to (10-20);

s5, sterilizing and drying.

Preferably, the carbonization step in step S3 is performed at 500 ℃ at 300 ℃ for 1-2 h.

Preferably, the municipal sludge-based biochar, the bentonite, the vermiculite, the attapulgite and the kaolinite described in the step S4 have a particle size of less than 2 mm.

Preferably, the other raw materials in step S4 further include at least one of nitrogen fertilizer, phosphate fertilizer and potassium fertilizer.

Preferably, the sterilization and drying method in step S5 is to place the semi-finished product of nutrient soil in a sterilizing oven for sterilization and drying, the temperature is controlled at 40-60 ℃ for 0.5-2h, and the water content is reduced to less than 10%.

Preferably, when the yield of the municipal sludge-based biochar-modified nutrient soil is less than 20kg, the method for sterilizing and drying in step S5 comprises the following steps:

s5.1, controlling the temperature of the semi-finished product of the nutrient soil uniformly mixed in the step S4 to be 100-;

and S5.2, adding a certain amount of water into the product sterilized in the step S5.1, uniformly mixing the product and the water again, and then drying the product at a low temperature.

The invention also discloses the municipal sludge-based biochar improved nutrient soil prepared by the method, and the municipal sludge-based biochar improved nutrient soil is loose in structure, irregular in shape and rough in surface.

The technical effects of the invention comprise: the prepared nutrient soil is rich in various nutrient elements required by plants by various raw materials, and provides basic fertility for plant growth; the nutrient soil is loose in texture, has a larger specific surface area and has large capacity of preserving fertilizer and moisture; the viability and the metabolic capacity of microorganisms in the nutrient soil are improved; can be used for fixing pollutants such as greenhouse gases, heavy metals and the like, and realizes the treatment of wastes with processes of wastes against one another.

Drawings

FIG. 1 is a flow chart of a production method of the municipal sludge-based biochar-modified nutrient soil of the invention;

FIG. 2 is a scanning electron microscope image of municipal sludge-based biochar;

FIG. 3 is an X-ray energy spectrum analysis diagram of municipal sludge-based biochar.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention discloses a production method of municipal sludge-based biochar modified nutrient soil, which comprises the following steps of:

s1, drying the municipal sludge in the air and then crushing the sludge; after air drying, the content of nitrogen in the municipal sludge is 2-5%, and the content of phosphorus in the municipal sludge is 1-3%;

s2, putting the crushed sludge into a roller machine for rolling to form flaky particles so as to facilitate subsequent carbonization;

s3, putting the flaky particles prepared in the S2 into a carbonization furnace for carbonization; preferably, the carbonization temperature is set to be 300-500 ℃, and the carbonization time is 1-2 hours, so as to prepare the municipal sludge-based biochar; the prepared municipal sludge-based biochar is shown in figure 2, and has a loose structure, an irregular shape and a rough surface; the municipal sludge-based biochar is subjected to X-ray energy spectrum analysis, and the result is shown in figure 3, wherein the municipal sludge-based biochar is rich in elements such as carbon, oxygen and the like, so that the municipal sludge-based biochar has rich surface oxygen-containing functional groups and is rich in elements such as iron, silicon, magnesium and the like required by plants;

s4, stirring and mixing the municipal sludge-based biochar prepared in the S3 and other raw materials to form nutrient soil; the municipal sludge-based biochar comprises, by mass, municipal sludge-based biochar, bentonite, vermiculite, attapulgite, kaolinite, diammonium phosphate, potassium sulfate and water, wherein the municipal sludge-based biochar comprises (5-25), (5-20), (1-5), (1-2) and (10-20); wherein, the bentonite, the vermiculite, the attapulgite and the kaolinite are all main components of the nutrient soil and also serve as main supports for the growth of crops; diammonium phosphate and potassium sulfate are used as supplementary materials to make up the fertility of the nutrient soil; the water is used for maintaining humidity, so that wet granulation is facilitated; the granularity of the municipal sludge-based biochar, bentonite, vermiculite, attapulgite and kaolinite is less than 2mm, so that the ventilation and water retention of the nutrient soil can be improved;

s5, sterilizing and drying to reduce the water content to below 10%, cooling and packaging.

The following description is given with reference to specific examples.

Example 1

This example was used to produce 1 ton of nutrient soil.

S1, taking 10 tons of sludge with the water content of about 50-60% from a municipal sewage treatment plant, air-drying for 20 days, and then crushing;

s2, putting the crushed sludge into a roller machine for rolling to form flaky particles with the thickness less than 1 cm;

s3, conveying the rolled flaky particles into a rotary carbonization furnace for carbonization, wherein the temperature is controlled to be about 400 ℃, and the carbonization time is set to be 1 hour;

s4, purchasing other ingredients from the market, weighing 0.2 ton of bentonite, 0.2 ton of vermiculite, 0.2 ton of kaolinite, 0.1 ton of attapulgite, 0.02 ton of diammonium phosphate and 0.01 ton of potassium sulfate, and transporting the weighed ingredients, 0.25 ton of municipal sludge-based biochar (taken) prepared in the step S3 and 0.1 ton of water to a stirrer to stir and mix the ingredients, so as to obtain a uniformly mixed semi-finished product of the nutrient soil;

and S5, conveying the semi-finished product of the nutrient soil uniformly mixed in the S4 to a sterilizing furnace, sterilizing and drying at low temperature, controlling the temperature at 50 ℃ and the running time at 1 hour to reduce the water content to below 10%, cooling and packaging.

The physical and chemical properties of the sludge-based biochar modified nutrient soil are determined, so that the soil structure is effectively improved, and the soil stability is obviously improved. The main reason is that the sludge-based biochar has a loose and porous structure, so that the nutrient soil has better water retention, moisture retention and fertilizer retention characteristics, the soil structure can be improved to be looser and not easy to harden, the effect of enhancing the microbial activity is obvious, and meanwhile, the higher specific surface area of the biochar also enables the biochar to have a better slow release effect on elements such as nitrogen, phosphorus and potassium.

Example 2

The embodiment is used for producing the municipal sludge-based biochar modified nutrient soil for rice seedling culture.

S1 and S2 are the same as S1 and S2 in example 1;

s3, conveying the rolled flaky particles into a rotary carbonization furnace for carbonization, wherein the temperature is controlled to be about 500 ℃, and the carbonization time is set to be 1 hour;

s4, purchasing other ingredients from the market, weighing 0.15 ton of bentonite, 0.15 ton of vermiculite, 0.15 ton of kaolinite, 0.20 ton of attapulgite, 0.03 ton of diammonium phosphate, 0.02 ton of potassium sulfate, 0.10 ton of municipal sludge-based biochar prepared in the example S3, 0.2 ton of water, a small amount of boric acid and manganese sulfate, and conveying the materials into a stirrer to stir and mix the materials to obtain a uniformly mixed semi-finished product of the nutrient soil;

s5 is the same as S5 in example 1.

The cultivation of young rice seedlings should be done by paying attention to the content of various nutrient elements, especially trace elements. Therefore, a small amount of boric acid and manganese sulfate are added in the process of producing the nutrient soil for the rice seedlings, thereby effectively preventing the common nutrient deficiency symptoms of the rice and ensuring the normal growth and development of the rice seedlings.

Example 3

The embodiment is used for producing the municipal sludge-based biochar modified nutrient soil for flower culture. In this example, approximately 10 kg of nutrient soil is produced.

S1, taking 100 kg of sludge with the water content of about 50-60% from a municipal sewage treatment plant, air-drying for about 10 days, crushing, removing impurities, and putting the air-dried sludge into a stirrer for crushing and mixing;

s2 and S3 are the same as S2 and S3 in example 2;

s4, purchasing other ingredients from the market, weighing 1 kg of bentonite, 1 kg of vermiculite, 1.5 kg of kaolinite and 2 kg of attapulgite, conveying the weighed ingredients and the municipal sludge-based biochar (2 kg) prepared in the S3 of the embodiment into a stirrer for stirring and mixing to obtain a uniformly mixed semi-finished product of the nutrient soil;

s5.1, putting the semi-finished product of the nutrient soil uniformly mixed in the step S4 into a large pot, stir-frying at the temperature of 150 ℃ for half an hour for disinfection and sterilization;

and S5.2, after disinfection and sterilization, adding 0.3 kg of diammonium phosphate, 0.2 kg of potassium sulfate and 2 kg of water, putting the mixture into a stirrer again, uniformly mixing, finally drying at low temperature, and packaging to obtain a nutrient soil finished product.

The preparation of the flower nutrient soil is carried out, and the disinfection and sterilization of the nutrient soil are fully considered, so that the semi-finished product is stir-fried and sterilized in a big pot in the production process; secondly, the pH value of the flower nutrient soil has obvious influence on the growth of flowers, and the existence of diammonium phosphate enables the nutrient soil to be weakly acidic, so that the method is suitable for cultivating neutral and acidic flowers, such as rhododendron, begonia, hydrangea, and the like; in addition, in the indoor flower cultivation, the watering frequency is obviously increased, but the fertilizing frequency is insufficient, so that the proportion of the biochar is improved, the fertilizer-keeping slow-release capacity is enhanced, and the contents of bentonite and vermiculite are reduced.

In conclusion, the municipal sludge-based biochar improves various raw materials of the nutrient soil, so that the nutrient soil is rich in various nutrient elements required by plants and provides basic fertility for plant growth; the biochar, the diammonium phosphate and the potassium sulfate provide necessary nitrogen and phosphorus elements for plants; the nutrient soil is loose in texture, has a larger specific surface area and has large capacity of preserving fertilizer and moisture; the survival rate of the microorganism is high, and the metabolic capability is improved; can fix pollutants such as greenhouse gases, heavy metals and the like, and realizes the treatment of wastes with processes of wastes against one another.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.