CN112047778A - Water-retaining slow-release organic fertilizer prepared by taking active silicon material as additive and preparation method thereof - Google Patents

Abstract

The invention discloses a water-retention slow-release organic fertilizer prepared by taking an active silicon material as an additive and a preparation method thereof. The invention provides a method for preparing an organic fertilizer, which comprises the following steps: 1) performing innocent treatment on the used active silicon adsorption material to degrade fluoranthene, pyrene,

Description

Water-retaining slow-release organic fertilizer prepared by taking active silicon material as additive and preparation method thereof

Technical Field

The invention belongs to the technical field of biology, and relates to a water-retention slow-release organic fertilizer prepared by taking an active silicon material as an additive and a preparation method thereof.

Background

China is a large coal using country, the discharge amount of coal-based solid waste is increasing day by day, the discharge amount is estimated to reach 30 hundred million t in 2020, and the discharge amount of fly ash reaches 9 hundred million t in 2020. In recent years, in the engineering laboratory for high-value utilization of coal-based solid waste in inner Mongolia autonomous region, the active silicon adsorbing material prepared from the coal-based solid waste and having developed pores and good adsorption performance has been developed, and can be used for synergistically removing SO in flue gas₂、NO_xAnd PM2.5 and a precursor thereof, but the active silicon adsorption material contains various pollutants in the flue gas after reaching saturation, and the problem of treatment and disposal of the used active silicon material becomes a bottleneck restricting the industrial application of the active silicon material.

The excess sludge in the municipal sewage treatment plant contains about 5 percent of monosaccharide, 2 to 8 percent of starch and more than 50 percent of rich organic matters in dry weight, and can effectively provide nutrient components for microorganisms.

Disclosure of Invention

An object of the present invention is to provide a method for preparing an organic fertilizer.

The method provided by the invention comprises the following steps: cow dung is used as a raw material, and an active silicon adsorption material is used as an additive to perform fermentation composting to obtain the organic fertilizer.

In the method, the aperture of the active silicon adsorption material is between 10 and 20nm, and the specific surface area is 200-300m²/g；

Or the active silicon adsorption material is an active silicon adsorption material containing organic pollutants after use (the preparation method of the active silicon adsorption material is described in the granted patent ZL2013106375529, and the publication number is CN 103736440A);

the content of the organic pollutants is lower than 5mg/kg (0-5mg/kg and is not equal to 5 mg/kg);

or, the organic contaminants include fluoranthene, pyrene, and/or perylene,

Benzo (b) fluoranthene and benzo (a) pyrene are 5 polycyclic aromatic hydrocarbons, and in the examples of the present invention, the organic contaminant content is considered to be the contaminant content of the 5 polycyclic aromatic hydrocarbons.

In the above method, the fermented compost comprises the following steps: uniformly mixing the active silicon adsorption material and the cow dung (in the embodiment, mixing according to the mass ratio of 1: 6) to obtain a composting raw material; adjusting the pH value of the composting raw material to 7 and the water content of the composting raw material to 60 percent, and adding straws to adjust the C/N ratio of the composting raw material to 20; then naturally fermenting and composting the regulated compost raw materials;

the reagent for adjusting the pH value of the compost raw material to 7 is acetic acid;

the reagent for adjusting the water content of the compost raw materials to 60 percent is water;

adjusting the C/N of the compost raw materials to be 20 as adding straws; the straw is corn straw.

The cow dung meets the following conditions: 37.45 percent of organic carbon, 1.65 percent of total nitrogen, 22.70 percent of C/N ratio, 8.4 of pH value and 73.3 percent of water content.

Or, the corn stalks satisfy the following conditions: 48.62% of organic carbon, 0.81% of total nitrogen, 60.02 of C/N ratio, 6.7 of pH value and 8.2% of water content.

The natural fermented compost is naturally fermented compost under the external environment (above 25 ℃), and the compost is turned over once every other week for about 2 months to obtain a thoroughly decomposed compost.

Or, the active silicon adsorption material which is used and contains organic pollutants with the content of less than 5mg/kg is prepared according to the following method: degrading the used active silicon adsorption material containing organic pollutants by using microorganisms in the activated sludge to realize the degradation of the organic pollutants.

The organic fertilizer prepared by the method is also within the protection scope of the invention.

It is another object of the present invention to provide the use of an active silica adsorbent material.

The invention provides application of an active silicon adsorption material in preparation of an organic fertilizer.

The invention also provides application of the active silicon adsorption material in promoting water retention of the organic fertilizer.

In the application, the aperture of the active silicon adsorption material is between 10 and 20nm, and the specific surface area is 200-300m²/g。

In the application, the active silicon adsorption material is used and contains organic pollutants; the organic pollutant content is less than 5 mg/kg.

In the above application, the organic contaminants include fluoranthene, pyrene,

Benzo (b) fluoranthene and benzo (a) pyrene, 5 polycyclic aromatic hydrocarbons.

In the application, the used active silicon adsorption material containing organic pollutants with the content of less than 5mg/kg is prepared according to the following method: degrading the used active silicon adsorption material containing organic pollutants with the content lower than 5mg/kg by using microorganisms in the activated sludge to realize the degradation of the organic pollutants.

The used active silicon adsorption material containing organic pollutants comprises fluoranthene, pyrene, fluorine,

The total content of 5 polycyclic aromatic hydrocarbons, namely benzo (b) fluoranthene and benzo (a) pyrene, is lower than 5mg/kg, so that the used active silicon adsorption material does not need to be treated by degrading organic pollutants; if the organic pollutants contain fluoranthene, pyrene,

Benzo (a)b) The total content of 5 polycyclic aromatic hydrocarbons, namely fluoranthene and benzo (a) pyrene, is higher than 5mg/kg, and the used active silicon adsorption material needs to be subjected to organic pollutant degradation treatment (harmless treatment);

in the method, the harmless treatment is to degrade the used active silicon adsorbent by using activated sludge so that the fluoranthene content in the used active silicon adsorbent is less than or equal to 0.68mg/kg, the pyrene content is less than or equal to 0.52mg/kg,

The content is less than or equal to 0.80mg/kg, the fluoranthene content is less than or equal to 0.48mg/kg, and the benzo (a) pyrene content is less than or equal to 0.46 mg/kg;

activated sludge generally refers to activated sludge in municipal sewage treatment plants; the activated sludge in the embodiment is taken from activated sludge in an aeration tank of a sewage treatment plant in 2017 of spring water affair sewage treatment limited company called Haote; the sludge contains 75-85% of organic matters and 15-25% of inorganic matters; the microbial population in the activated sludge mainly comprises bacteria, yeast, fungi and actinomycetes.

The harmless treatment specifically comprises the following steps:

A. mixing the used active silicon adsorption material with active sludge according to the mass ratio of 1:6 to obtain a mixture;

B. and adjusting the pH value of the mixture to 7, and reacting for 5 days at 32 ℃ to obtain the harmless treated active silicon material.

The microbial fertilizer prepared by the method is also protected by the invention.

The invention provides the method for degrading organic pollutants adsorbed by the active silicon adsorption material by using microorganisms, and applying the active silicon adsorption material after the microbial treatment to the preparation of the fertilizer, so that the harmless treatment of the active silicon adsorption material can be realized, the water-retaining slow-release functional fertilizer can be prepared by using the adsorption property of the active silicon, and the method has wide application prospect.

According to the invention, the active silicon adsorption material (the active silicon material after harmless treatment) after microbial treatment is used as an additive, cow dung is used as a main raw material, corn straw is used as a regulator, and the mixture is fermented to prepare the organic fertilizer, so that the obtained organic fertilizer can effectively improve nutrient substances in soil, improve the soil structure and has a certain water retention function.

Experiments prove that the used active silicon adsorbing material is used as an additive in the cow dung composting process after being subjected to harmless treatment by using activated sludge, and the production method has the advantages of simple process and reasonable component proportion; not only can make fertilizer can adjust the soil structure, provide nutrient substance for the plant, have certain water retention function, can effectually solve the processing and the processing problem of using back active silicon material moreover, break through the bottleneck that restricts active silicon material industrialization and use, can solve the processing problem of cow dung simultaneously, can effectually realize the cyclic utilization of resource, realized waste utilization, reduce environmental pollution, kill two birds with one stone.

Drawings

FIG. 1 is the change in pH during composting.

FIG. 2 shows the change in conductivity during composting.

Fig. 3 shows the change of Total Carbon (TC) of the fertilizer during composting.

Fig. 4 shows the change in Total Nitrogen (TN) of the fertilizer during composting.

FIG. 5 is the change in Germination Index (GI) during composting.

FIG. 6 is the water absorption performance of the fertilizer.

Fig. 7 is a graph of the change in temperature of the manure during composting.

FIG. 8 is a graph of the change in moisture content of the fertilizer during composting.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The preparation method of the active silicon adsorption material in the following examples is described in the granted patent ZL2013106375529 with the publication number CN103736440A, and the obtained active silicon adsorption material has the pore diameter of 10-20nm and the specific surface area of 200-300m²/g。

Example 1 organic fertilizer prepared with post-use active silica adsorbent Material as additive

Treatment of used active silicon adsorption material as compost additive

After the active silicon adsorption material adsorbs the flue gas, detecting the used active silicon adsorption material adsorbing the flue gas, if fluoranthene, pyrene, etc. in the organic pollutants,

The total content of 5 polycyclic aromatic hydrocarbons, namely benzo (b) fluoranthene and benzo (a) pyrene, is less than 5mg/kg, so that the used active silicon adsorption material does not need to be treated by degrading organic pollutants; if the organic pollutants contain fluoranthene, pyrene,

And the total content of 5 polycyclic aromatic hydrocarbons, namely benzo (b) fluoranthene and benzo (a) pyrene, is more than or equal to 5mg/kg, so that the used active silicon adsorption material needs to be subjected to organic pollutant degradation treatment (harmless treatment).

1. Used active silicon material

The used active silicon adsorption material is obtained by adsorbing organic pollutants in smoke by using an active silicon material, and the organic pollutants in the used active silicon adsorption material contain fluoranthene, pyrene,

Benzo (b) fluoranthene and benzo (a) pyrene, 5 polycyclic aromatic hydrocarbons.

The post-use active silica sorbent materials in this example were derived from the following:

active silicon adsorption material (pore diameter between 10-20nm, specific surface area between 200-300 m)²And/g) is taken from a coal-based solid waste high-value utilization engineering laboratory in an inner Mongolia autonomous region.

The active silicon adsorption material is cooperated to remove SO in the flue gas₂NOx and PM2.5 and precursors thereof, and the active silicon adsorption material contains a plurality of organic pollutants in the smoke after reaching saturation, wherein the organic pollutants contain fluoranthene, pyrene,

5 kinds of polycyclic aromatic hydrocarbons, benzo (b) fluoranthene and benzo (a) pyrene.

After detection, the used active silicon adsorption material contains fluoranthene, pyrene,

The concentrations of the benzo (b) fluoranthene and the benzo (a) pyrene are respectively 2.36mg/kg, 1.72mg/kg, 2.75mg/kg, 1.29mg/kg and 1.26mg/kg, and the total concentration of the 5 polycyclic aromatic hydrocarbon organic pollutants is 9.38mg/kg (more than 5 mg/kg).

2. Activated sludge

Activated sludge generally refers to activated sludge in municipal sewage treatment plants; the activated sludge in the embodiment is the activated sludge taken from an aeration tank of a sewage treatment plant from 2017 of spring water affair sewage treatment limited company called Haote; the sludge contains 75-85% of organic matters and 15-25% of inorganic matters; the microbial population in the activated sludge mainly comprises bacteria, yeast, fungi and actinomycetes.

3. Treatment for degrading organic pollutants (innocent treatment)

The method for degrading the polycyclic aromatic hydrocarbon in the active silicon adsorbing material by using the microorganisms in the active sludge in the step 2 comprises the following steps:

mixing the used activated silicon adsorption material (wherein the total concentration of 5 polycyclic aromatic hydrocarbon organic pollutants is 9.38mg/kg) in the step 1 with activated sludge according to the mass ratio of 1:6 to obtain a mixture, and adjusting the pH value to 7; and then reacting for 5 days at 32 ℃ to realize degradation of the polycyclic aromatic hydrocarbon, thereby obtaining the harmless treated active silicon material.

The method for detecting the content of the polycyclic aromatic hydrocarbon in the activated silicon material subjected to harmless treatment and the used activated silicon adsorbing material of the 1 is carried out according to a method in the United states Environmental Protection Agency (EPA) in an experiment, and specifically comprises the following steps: the method comprises the following steps of eluting and extracting the polycyclic aromatic hydrocarbon in the active silicon adsorption material by using an organic solvent dichloromethane, and then qualitatively and quantitatively detecting the type and the content of the polycyclic aromatic hydrocarbon in a sample by using a gas chromatography-mass spectrometer, wherein the method comprises two steps of extraction and detection, wherein the extraction step comprises three parts: eluting and extracting, rotary evaporating, chromatographic separating, and detecting the sample after chromatographic separation by a gas chromatography-mass spectrometer. And (5) detecting the PAHs sample by using a gas chromatograph-mass spectrometer. The adjusting parameters are as follows: an FID detector is adopted, nitrogen is used as carrier gas, the flow rate is 1ml/min, the temperature of a column box is programmed at the speed of 5 ℃/min, the temperature is increased from 130 ℃ to 260 ℃, the temperature is kept for 30min, and the sample injection temperature is set to be 250 ℃.

The results show that the method has the advantages of high yield,

the used active silicon adsorption material of the 1 above mainly contains fluoranthene, pyrene,

5 kinds of polycyclic aromatic hydrocarbon of benzo (a) fluoranthene and benzo (b) pyrene, the content is respectively 2.36mg/kg, 1.72mg/kg, 2.75mg/kg, 1.26mg/kg and 1.29mg/kg, the total amount is 9.38 mg/kg;

fluoranthene, pyrene, etc. in active silicon material treated in harmless way,

The contents of 5 polycyclic aromatic hydrocarbons including benzo (a) fluoranthene and benzo (b) pyrene are respectively 0.68mg/kg, 0.52mg/kg, 0.80mg/kg, 0.48mg/kg and 0.46mg/kg, and the total amount is 2.94mg/kg (less than 5 mg/kg).

The above results indicate that the degradation rate of 5 polycyclic aromatic hydrocarbons is 69%.

Secondly, the active silicon material is used for fermenting cow dung fertilizer

The physical and chemical properties of the cow dung are that the organic carbon content is 37.45 percent, the total nitrogen is 1.65 percent, the C/N (total carbon/total nitrogen ratio) is 22.70, the pH value is 8.4, and the water content is 73.3 percent.

The physicochemical properties of the corn straw are that the organic carbon content is 48.62%, the total nitrogen content is 0.81%, the C/N ratio is 60.02, the pH value is 6.7, and the water content is 8.2%.

1. Compost

The method is characterized in that fresh cow dung is used as a raw material, corn straws are used as a regulator, an active silicon adsorption material is used as a water-retaining agent, and composting is carried out, and the method specifically comprises the following steps:

fluoranthene, pyrene and the like in the organic pollutants obtained in the previous step,

Mixing 5 used active silicon adsorbing materials (subjected to harmless treatment) of which the total content of 5 polycyclic aromatic hydrocarbons, namely benzo (b) fluoranthene and benzo (a) pyrene is less than 3mg/kg, with cow dung according to the mass ratio of 1:6 to obtain a composting material; adjusting the pH value of the compost raw material to 7 by using acetic acid, adjusting the water content to 60% by using water, and adding a corresponding amount of straws according to the ratio of the content of organic carbon and nitrogen in the straws to the content of organic carbon and nitrogen in cow dung to adjust to obtain an adjusted compost raw material, so that the C/N of the adjusted compost raw material is 20;

naturally fermenting and composting the regulated compost raw materials in an external environment (above 25 ℃), turning the compost once every other week for about 2 months to obtain a decomposed compost, namely the organic fertilizer.

In the composting process, the composting temperature reaches above 59 ℃ in 14 days, and the time of exceeding 55 ℃ is 11 days.

2. Detecting fertilizer

Sampling and measuring the temperature, the water content, the pH, the conductivity (EC), the Total Carbon (TC), the Total Nitrogen (TN), the C/N and the Germination Index (GI) in the composting process, wherein the detection method comprises the following steps:

(1) determination of temperature

Measuring the temperature once every 2 days, measuring the temperature at 3 pm every time, measuring the highest temperature of the stack body every time, measuring the average temperature twice at the front, middle and rear three parts of the stack body at a position which is 50cm away from the surface of the stack body respectively, and recording the ambient temperature. While observing and recording the characteristics and changes of the surface of the stack.

The results are shown in FIG. 7, where the temperature was gradually increased to the maximum temperature for the first 15 days, followed by a gradual decrease in temperature, indicating that the fermentation was complete.

(2) Measurement of Water content

Cleaning glass ware, putting the glass ware into a drying oven and drying the glass ware to constant weight M₁Sample M₂Putting about 10g of the mixture into a glass dish, then putting the glass dish into an oven to be dried for 12 hours at 105 ℃ until the weight is constant, taking out and weighing the glass dish, and recording the mass as M₃Two replicates were set up for each sample. The water content η of the sample is calculated as follows:

as a result, as shown in FIG. 8, the moisture content of the organic fertilizer was slowly decreased within 55 days of the test from the initial moisture content of 65% to 35%, and the organic fertilizer obtained by the method of the present invention was able to retain water for a long period of time.

(3) Determination of pH and conductivity

Mixing 10g of a fresh sample with 100mL of distilled water, placing the mixture on a shaking table, shaking for 2h, standing for 30min, and measuring the pH and the conductivity of the sample by using a pH meter and a conductivity meter respectively, wherein two times are set for each sample.

The results are shown in FIGS. 1 and 2.

(4) Determination of total nitrogen content

According to the national standard NY525-2012 of the organic fertilizer, a Kjeldahl method is adopted.

The results are shown in FIG. 3.

(3) Determination of the Total carbon content

According to the national standard NY525-2012 of the organic fertilizer, a potassium dichromate volumetric method is adopted.

The results are shown in FIG. 4.

(5) Determination of germination index

Taking 10g of a fresh sample, placing the fresh sample into 100mL of deionized water, shaking the fresh sample on a shaking table for 24 hours, filtering to obtain filtrate, placing 10mL of the filtrate into culture dishes padded with filter paper, placing 20 rich and full Chinese cabbage seeds into each culture dish, placing the culture dishes into a constant-temperature incubator at 25 ℃ for culturing for 48 hours, and setting two repetitions for each sample by taking the deionized water as a reference. The formula for calculating the germination index GI is as follows:

as shown in FIG. 5, the Germination Index (GI) of the fertilizer sample leaching solution reached 50% in less than 20 days, and the Germination Index (GI) reached 110% in about 42 days.

Judging the composting situation of the compost according to the parameter results, and considering that the compost reaches the composting state when C/N in the fertilizer is less than 20 (the ratio is less than 20 in 2 months) and the Germination Index (GI) is more than 110 percent, so as to obtain the composted compost, wherein the time is about 2 months; the conductivity (EC) of the reactor body after the decomposition is less than 8mS/cm (parameter for judging the decomposition state).

(6) Water absorption performance

The water absorption capacity is measured by the method in GB/T8770-2014, and the test result is shown in figure 6, and the test result shows that the saturated water absorption capacity per gram can reach 11 g.

3. Heavy metal content detection

Detecting the content of heavy metals in the composted compost, wherein the method for determining the content of the heavy metals is determined according to the national standard NY525-2012 of the organic fertilizer, and comprises the following steps: the arsenic content determination method comprises the following steps: atomic fluorescence photometry; the mercury content determination method comprises the following steps: atomic fluorescence photometry; the lead content determination method comprises the following steps: atomic absorption photometry; the method for measuring the cadmium content comprises the following steps: atomic absorption photometry; the method for measuring the chromium content comprises the following steps: atomic absorption photometry.

The heavy metal content is required to meet the national standards of less than or equal to 15 As, less than or equal to 2 Hg, less than or equal to 50 Pb, less than or equal to 3 Cd and less than or equal to 150 Cr.

As a result, the As content in the decomposed pile was 2.88mg/kg, the Pb content was 14.27mg/kg, and the Cr content was 7.98mg/kg, and Hg and Cd were not contained.

Therefore, the obtained decomposed compost is the organic fertilizer.

Claims (10)

1. A method for preparing an organic fertilizer, comprising the steps of: cow dung is used as a raw material, and an active silicon adsorption material is used as an additive to perform fermentation composting to obtain the organic fertilizer.

2. The method of claim 1, wherein:

the specific surface area of the active silicon adsorption material is 200-300m²/g；

Or the active silicon adsorption material is used and contains organic pollutants;

the content of the organic pollutants is less than 5 mg/kg.

3. The method of claim 2, wherein: the organic pollutants are fluoranthene, pyrene,

Benzo (b) fluoranthene and benzo (a) pyrene, 5 polycyclic aromatic hydrocarbons.

4. A method according to any one of claims 1-3, characterized in that:

the fermented compost comprises the following steps: uniformly mixing the active silicon adsorption material and the cow dung to obtain a composting raw material; adjusting the pH value of the composting raw material to 7 and the water content of the composting raw material to 60 percent, and adding straws to adjust the C/N ratio of the composting raw material to 20; and then naturally fermenting and composting the regulated compost raw materials.

5. An organic fertilizer produced by the process of any one of claims 1 to 4.

6. Use of an activated silicon sorbent material according to any one of claims 1 to 4 in the preparation of an organic fertilizer.

7. Use of an activated silicon sorbent material according to any one of claims 1 to 4 for promoting retention of water in an organic fertilizer.

8. Use according to claim 6 or 7, characterized in that: the specific surface area of the active silicon adsorption material is 200-300m²/g。

9. Use according to any one of claims 6 to 8, characterized in that: the active silicon adsorption material is used and contains organic pollutants;

the content of the organic pollutants is less than 5 mg/kg.

10. Use according to claim 9, characterized in that: the organic dirtThe dye is fluoranthene, pyrene,

Benzo (b) fluoranthene and benzo (a) pyrene, 5 polycyclic aromatic hydrocarbons.

Images