Dehydrating agent for fermentation of livestock manure with high water content and application of dehydrating agent

Abstract

The invention discloses a dehydrating agent for fermentation of livestock manure with high water content and application of the dehydrating agent. The dehydrating agent is prepared from calcium oxide, kieselguhr and vinegar residues or mushroom dregs with the pH value of 5.5-6.5 or kitchen garbage with oil and salt removed according to the mass ratio of 2: (3-5): (3-5). The dehydrating agent disclosed by the invention not only can quickly change the distribution characteristics of moisture in the livestock and poultry manure to quickly release bound water in the material, but also has the effects of adsorbing moisture and reducing the content of free water in the material, and can quickly reduce the moisture content of the compost material through quick heating, improve the compost environment and accelerate the start of compost fermentation. By adopting the fermentation method disclosed by the invention, the composting utilization efficiency of materials with high bound water content, such as livestock manure, can be improved, and the organic fertilizer prepared by the method is high in calcium content; in addition, the vinegar residues, the mushroom dregs and the kitchen garbage can serve as fermentation raw materials to enrich nutrients of the prepared organic fertilizer, and meanwhile resource utilization of the wastes is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of organic fertilizers, and in particular to a dehydrating agent for fermenting high-water-content poultry and livestock manure and its application. Background Art

[0002] Aerobic composting is one of the effective measures to achieve the reduction, harmlessness and resource utilization of livestock and poultry manure. The moisture content of composting materials is an important indicator that affects the degree of microbial reproduction during the composting process, which in turn affects the composting cycle and product quality: if the moisture content of livestock and poultry manure is too low, the microorganisms will reproduce slowly; if the moisture content is high, it is easy to block the pores in the pile, affecting ventilation and leading to anaerobic fermentation. Practical experience shows that the optimal moisture content of composting materials is 50%-65%, while the moisture content of fresh livestock and poultry manure is usually ≥80%. According to the difficulty of removing water from livestock and poultry manure, it is divided into two forms: free water and bound water. Free water is distributed around the solid particles of manure, is not bound by solid particles, has almost no binding force with solid particles, and is not affected by the capillary action of sludge. Its properties are similar to those of pure water and are relatively easy to remove. This part of water can generally be separated from manure by concentration or mechanical dehydration. Bound water forms a certain binding force with solid particles, and its mobility is restricted. Even high-intensity mechanical force cannot completely remove it, and it can only be removed by heating, etc. Most of the water in high-water-content livestock and poultry manure exists in a bound state and cannot be directly used by microorganisms, which seriously affects the mixing of materials and the utilization of microorganisms. Therefore, the distribution of water form in livestock and poultry manure has a great impact on the composting efficiency, composting time, manpower and cost of livestock and poultry manure.

[0003] In order to improve the composting efficiency of high-water-content livestock manure, it is necessary to change the water holding form in livestock manure. Converting the high-binding energy form of water that is difficult to remove in livestock manure into the low-binding energy form of water that is easy to remove is the main direction of research on livestock manure dehydration technology. At present, the technologies and methods for reducing the moisture content of livestock manure mainly include natural sunlight drying, biological drying, high-temperature rapid drying, drying and puffing drying, and mechanical dehydration drying, but these methods have the defects of polluting the atmospheric environment, occupying a large area, and high energy consumption. Therefore, a product and method that can be combined with the composting process to quickly change the moisture form in livestock manure in situ is developed. Summary of the invention

[0004] The invention provides a dehydrating agent for fermenting poultry and livestock manure with high water content. The dehydrating agent is composed of calcium oxide, diatomaceous earth and vinegar grains in a mass ratio of 2:3-5:3-5.

[0005] Preferably, the dehydrating agent is composed of calcium oxide, diatomaceous earth and vinegar grains in a mass ratio of 2:4:4.

[0006] The water content of the high-water-content livestock manure is 70-90%.

[0007] Furthermore, the vinegar residue can also be replaced by fungus residue with a pH of 5.5-6.5 or kitchen waste from which oil and salt have been removed.

[0008] The present invention also provides a method for fermenting livestock manure with high water content. Before fermentation, the above-mentioned dehydrating agent is added to the livestock manure with high water content. The amount of the dehydrating agent added is 15%-30% of the weight of the livestock manure to be processed.

[0009] Preferably, the amount of the dehydrating agent added is 20% of the weight of the livestock manure to be processed.

[0010] Specifically, the fermentation method is to first add the mixed calcium oxide and diatomaceous earth to the poultry and livestock manure, then add the vinegar dregs and mix again, and then ferment according to the conventional fermentation method.

[0011] Preferably, the dehydrating agent can be used for fermentation of livestock manure with high water content under low temperature conditions in winter.

[0012] The winter low temperature condition refers to an average temperature ≤ 15°C.

[0013] The beneficial effects of the present invention include:

[0014] The dehydrating agent material composition and use method provided by the present invention are simple. First, calcium oxide and diatomaceous earth are mixed and then mixed with high-water-content poultry and livestock manure, and then vinegar dregs, fungus residues or deoiled and desalted kitchen waste are added and mixed. Calcium oxide is used to react with free water in poultry and livestock manure to release heat, and while promoting the conversion of bound water in poultry and livestock manure into free water, a certain amount of weakly alkaline substances such as calcium hydroxide are produced, and acid-base neutralization occurs with weakly acidic substances such as added vinegar dregs, ensuring that the pH of the material tends to be neutral, and while increasing the material temperature, the rapid release of bound water in the material is promoted, thereby effectively accelerating the composting fermentation speed. The high porosity and adsorption of diatomaceous earth can quickly adsorb water in chicken manure that is converted from a bound state to a free state after the temperature rises, quickly reduce the water content of the compost material, improve the composting environment, and increase the heating rate. In addition, diatomaceous earth also provides a growth environment for microorganisms in the compost, promotes microbial growth and metabolism, and then increases the composting rate. Adding weakly acidic substances such as vinegar dregs can extend the temperature holding time, and has a certain pH buffering effect. The fermentation method of the present invention can not only improve the composting efficiency of materials with high bound water content such as livestock manure, but also the organic fertilizer prepared by the method has a high calcium content and has a certain function of supplementing calcium elements; the addition of vinegar dregs, fungus residues, and kitchen waste in the present invention can also be used as fermentation raw materials to enrich the nutrients of the prepared organic fertilizer, and also realize the resource utilization of these wastes. In addition, the fermentation method of the present invention can be used for the fermentation of livestock manure with high water content under low temperature conditions in winter (average temperature ≤ 15°C), and the dehydrating agent of the present invention can accelerate the fermentation start under low temperature conditions in winter, solving the technical problem of slow fermentation speed in winter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The free water content results of different treatments in Example 1;

[0016] Figure 2 is the pH value of different treatments in Example 1;

[0017] Figure 3 The free water content results of different treatments in Example 2;

[0018] Figure 4 The free water content results of different treatments in Example 3;

[0019] Figure 5 These are the temperature results for different treatments in Example 4. DETAILED DESCRIPTION

[0020] The present invention is further illustrated and described below in conjunction with embodiments, but the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the present invention and embodiments, all other inventions and embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0022] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0023] Example 1, dehydrating agent formulation composition experiment

[0024] (1) Experimental setup: The experiment was set up according to the following experimental treatments ①-④. The components in each treatment were added in order according to the mass ratio. Calcium oxide and diatomaceous earth could be mixed and added together. The vinegar residue needed to be added and mixed after calcium oxide, diatomaceous earth and chicken manure were evenly mixed. Fresh chicken manure alone was used as a control treatment (CK). Three replicates were set for each treatment. The experiment was conducted at an indoor temperature of 26° C. The moisture content of the fresh chicken manure used in this embodiment was 81% (mass percentage).

[0025] ①20g CaO+300g fresh chicken manure;

[0026] ②20g CaO+50g diatomaceous earth+300g fresh chicken manure;

[0027] ③20g CaO+50g vinegar residue+300g fresh chicken manure;

[0028] ④20g CaO + 50g diatomaceous earth + 300g fresh chicken manure + 50g vinegar residue;

[0029] (2) Test method

[0030] Temperature: Use a thermometer to test directly. After each treated material is completely mixed, measure and record the temperature of the mixed material every 2 minutes;

[0031] Free water content: After 30 minutes of reaction, take 50g of sample and put it into a 100mL centrifuge tube. Each centrifuge tube needs to be weighed. Stir manually and centrifuge at 5000rpm for 10min. Pour out the supernatant, weigh and record.

[0032] pH value: After reacting for 30 minutes, weigh 10.0g±0.1g of the sample, place it in a 100mL beaker, add 50mL of water without carbon dioxide, stir for 1min, let it stand for 30min, and take the supernatant to measure with a pH meter.

[0033] (3) Test results of each treatment temperature

[0034] The temperatures measured within 11 minutes for each treatment are shown in Table 1. The experimental results show that the temperature changes of each treatment with the addition of dehydrating agent components are significantly different from those of CK. There was no difference in temperature between the treatments with the addition of dehydrating agent components in the first 3 minutes, but there were significant differences compared with CK. Starting from 5 minutes, the temperatures of treatments ①② gradually differed from those of treatments ③④, indicating that the addition of vinegar lees is beneficial to prolonging the temperature holding time. Therefore, as shown in the results of treatment ④ in Table 1, the dehydrating agent, compounded with diatomaceous earth and vinegar lees, is more conducive to heat release and maintenance of the heat release effect on the basis of calcium oxide.

[0035] Table 1 Evaluation of heat release effect of dehydrating agent

[0036]

[0037] Note: The significant difference levels in Table 1 are the differences between different treatments in the same time period.

[0038] (4) Determination of free water content in each treatment

[0039] The free water content of the material was measured after 30 minutes of reaction. Figure 1 The experimental results showed significant differences among different treatments. The heat generated by the reaction between chicken manure and calcium oxide in treatment ① significantly converted the bound water in chicken manure into free water, which significantly increased the free water content of treatment 1 compared with CK. The free water content of treatment ③ (calcium oxide + vinegar lees) was the highest, indicating that the heat released by the reaction of calcium oxide, vinegar lees and fresh chicken manure can significantly convert the bound water in chicken manure into free water, increasing the free water content. The free water content of treatment ② (calcium oxide + diatomaceous earth) was lower than that of treatment ① because the added diatomaceous earth had excellent water absorption and adsorbed the converted free water. The free water content of treatment ④ was lower than that of treatment ③, but higher than that of treatment ②, which also indicated that calcium oxide and vinegar lees reacted with water in chicken manure, and part of the bound water was converted into free water and adsorbed by diatomaceous earth.

[0040] (5) pH value of each treatment

[0041] The pH of the material was measured after 30 minutes of reaction. Figure 2 The experimental results show that there are differences between different treatments. Adding calcium oxide and diatomaceous earth will increase the pH value of the material. Adding vinegar dregs can effectively adjust the pH value of the material to neutral, which is conducive to the start of composting in the later stage.

[0042] In summary, calcium oxide mixed with fresh chicken manure can effectively release bound water in chicken manure, and adding diatomaceous earth can help to enhance the heat release effect to a certain extent, and has a certain free water adsorption effect. Adding vinegar dregs can help to extend the heat release time and have a certain pH buffering effect. Therefore, the dehydrating agent formula selects calcium oxide, diatomaceous earth and vinegar dregs.

[0043] Example 2, Dehydrating agent component ratio experiment

[0044] This example further studies the reasonable and economical combination ratio of calcium oxide, diatomaceous earth and vinegar grains on the basis of Example 1, and reduces the amount of auxiliary materials diatomaceous earth and vinegar grains as much as possible while ensuring the use effect.

[0045] (1) Experimental setup: The experiment was set up according to the following experimental treatments ①-⑥ (wherein the ratio of calcium oxide, diatomaceous earth and vinegar residue is the mass ratio). Calcium oxide and diatomaceous earth were mixed and then fully mixed with fresh chicken manure, and then mixed with vinegar residue and stirred evenly. Each treatment was repeated 3 times, and the indoor temperature was 22°C.

[0046] ①60g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:2:2) + 200g fresh chicken manure;

[0047] ②60g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:3:3) + 200g fresh chicken manure;

[0048] ③60g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:4:4) + 200g fresh chicken manure;

[0049] ④60g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:5:5) + 200g fresh chicken manure;

[0050] ⑤60g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:6:6) + 200g fresh chicken manure;

[0051] ⑥CK 200g fresh chicken manure

[0052] (2) Test method:

[0053] Free water content: 10 minutes after complete mixing, take 50g of sample and put it into a 100mL centrifuge tube. Each centrifuge tube needs to be weighed. Stir manually and centrifuge at 5000rpm for 10min. Pour out the supernatant, weigh and record.

[0054] (3) Experimental results:

[0055] The free water content results of the dehydrating agent formula ratio experiment ( Figure 3) It can be seen that as the ratio of diatomite and vinegar dregs increases, the free water content in chicken manure increases first and then decreases. Among them, the treatment of calcium oxide, diatomite and vinegar dregs = 2:6:6 is not significantly different from CK. This is because the released free water is reabsorbed by a large amount of diatomite. Low free water content is not conducive to the start of composting fermentation. Therefore, the ratio of diatomite and vinegar dregs in the dehydrating agent formula should not exceed 2:5:5. The treatment of calcium oxide, diatomite and vinegar dregs = 2:2:2 is significantly different from the other dehydrating agent treatments. Therefore, the optimal ratio of calcium oxide, diatomite and vinegar dregs should be in the range of 2:3-5:3-5.

[0056] Example 3: Dehydrating agent usage experiment

[0057] On the basis of the above experiments, the reasonable amount of dehydrating agent is further studied. It can be seen from Example 2 that when the amount of dehydrating agent added is 30% of the weight of fresh chicken manure, the use effect is good. In order to minimize the use cost, this experiment further studies the use effect of two formulas of dehydrating agent with calcium oxide, diatomaceous earth and vinegar dregs = 2:5:5 and calcium oxide, diatomaceous earth and vinegar dregs = 2:3:3 when the addition amount is 10% and 15%.

[0058] (1) Experimental setup: The experiment was set up as follows: calcium oxide and diatomaceous earth were mixed evenly with fresh chicken manure, and then mixed with vinegar residue. Each treatment was repeated 3 times, and the indoor temperature was 22°C.

[0059] ①20g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:5:5) + 200g fresh chicken manure

[0060] ②30g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:5:5) + 200g fresh chicken manure

[0061] ③20g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:3:3) + 200g fresh chicken manure

[0062] ④30g dehydrating agent (calcium oxide, diatomaceous earth and vinegar residue = 2:3:3) + 200g fresh chicken manure

[0063] ⑤CK 200g fresh chicken manure

[0064] (2) Test method:

[0065] Free water content: Take 50g of sample 10 minutes after complete mixing and put it into a 100mL centrifuge tube. Each centrifuge tube needs to be weighed. Stir manually and centrifuge at 5000rpm for 10min. Pour out the supernatant, weigh and record.

[0066] (3) Experimental results

[0067] The free water content results of the dehydrating agent dosage experiment ( Figure 4) It can be seen that the free water content of the dehydrating agent with a formula of calcium oxide, diatomaceous earth and vinegar lees = 2:3:3 is significantly different between 10% and 15%; similarly, the free water content of the dehydrating agent with a formula of calcium oxide, diatomaceous earth and vinegar lees = 2:5:5 is also significantly different between 10% and 15%, so the minimum dosage of the dehydrating agent is set to 15%, and the addition amount of the dehydrating agent is preferably controlled at 15%-30%.

[0068] Example 4: Specific application effect of dehydrating agent

[0069] (1) Material to be processed: fresh chicken manure (water content 88%, pH = 7.8)

[0070] (2) Dehydrating agent (mass ratio): calcium oxide: diatomaceous earth: vinegar residue = 2:5:5

[0071] (3) Treatment settings: When the average outside temperature is ≤15°C, fresh chicken manure and straw powder are mixed, and then calcium oxide and diatomaceous earth mixture is added according to the following treatment ratio. After mixing, vinegar residue is added according to the ratio and mixed again. After reacting for 10 minutes, the pile temperature is measured. After reacting for 10 hours, the pile temperature is measured again.

[0072] CK: 1 ton of chicken manure + 0.5 ton of straw powder

[0073] 30% addition amount: CK + 0.45 tons of dehydrating agent

[0074] 20% addition amount: CK + 0.3 tons of dehydrating agent

[0075] 15% addition amount: CK + 0.225 tons of dehydrating agent

[0076] 10% addition amount: CK + 0.15 tons of dehydrating agent

[0077] (4) Application effect

[0078] a. The temperature of the pile after adding dehydrating agent to fresh chicken manure for 10 minutes

[0079] like Figure 5 As shown, adding different amounts of dehydrating agent can significantly increase the temperature of the material pile, and there are significant differences due to the different amounts of dehydrating agent added. The difference in temperature rise between 20% and 30% is not significant. Therefore, the economical addition amount of dehydrating agent can achieve the best effect by controlling the mass ratio of 15-20% of the pile material. The material temperature is higher when the addition amount is 30% than that of 20%, but the difference is not significant.

[0080] b. The temperature of the pile 10 hours after adding dehydrating agent to fresh chicken manure

[0081] Since the addition of dehydrating agent increases the composting temperature of materials through chemical reaction, releases the bound water in materials and helps to start aerobic fermentation under low temperature conditions, it is suitable for dehydrating chicken manure and low-temperature composting under low temperature conditions in winter (average temperature ≤ 15°C). The temperature of the pile body was measured after 10 hours of dehydration reaction and it was found that all pile bodies treated with dehydrating agent entered the normal fermentation process, but the CK treatment was still in the state of surrogate startup. Therefore, while the dehydrating agent effectively releases the bound water in the material and promotes the fermentation speed, it also helps to speed up the start of composting under low temperature conditions.

[0082] Summarizing the above experiments, it is concluded that the components of the dehydrating agent are calcium oxide, diatomaceous earth, and vinegar lees, and the mass ratio of the components is calcium oxide, diatomaceous earth and vinegar lees = 2:3-5:3-5, preferably, calcium oxide, diatomaceous earth and vinegar lees = 2:4:4; the most economical and optimal usage of the dehydrating agent is 15%-30% of the weight of the treated material, and preferably, the usage of the dehydrating agent is 20% of the weight of the treated material.

Claims

1. A dehydrating agent for fermentation of high-water-content livestock manure, characterized in that: The dehydrating agent is composed of calcium oxide, diatomaceous earth and vinegar grains in a mass ratio of 2:3-5:3-5.

2. The dehydrating agent according to claim 1, characterized in that The dehydrating agent is composed of calcium oxide, diatomaceous earth and vinegar grains in a mass ratio of 2:4:

4.

3. The dehydrating agent according to claim 1, characterized in that The water content of the high-water-content livestock manure is 70-90%.

4. The dehydrating agent according to claim 1, characterized in that The vinegar residue is replaced by fungus residue with a pH value of 5.5-6.5 or kitchen waste from which oil and salt are removed.

5. A method for fermenting high-water content livestock manure, characterized in that: Before fermentation, the dehydrating agent according to any one of claims 1 to 4 is added to the livestock manure with high water content, and the added amount of the dehydrating agent is 15% to 30% of the weight of the livestock manure to be processed.

6. The fermentation method according to claim 5, characterized in that The economic addition amount of the dehydrating agent is 20% of the weight of the livestock excrement to be processed.

7. The fermentation method according to claim 5, characterized in that Firstly, the mixed calcium oxide and diatomaceous earth are added to the livestock manure, and then the vinegar residue is added and mixed again, and then fermentation is carried out according to a conventional fermentation method.

8. The fermentation method according to any one of claims 5 to 7, characterized in that: The dehydrating agent is used for fermenting livestock manure with high water content under low temperature conditions in winter.

9. The fermentation method according to claim 8, characterized in that The winter low temperature condition refers to an average temperature ≤ 15°C.

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