An ammonia inhibitor for a livestock manure conversion process and a method for manure conversion

Abstract

The present disclosure provides an ammonia inhibitor for livestock and poultry manure conversion process and a method for manure conversion, relating to the technical field of livestock and poultry manure treatment. The ammonia inhibitor for livestock and poultry manure conversion process comprises a metabolic inhibitor and a pH regulator, the metabolic inhibitor is copper sulfate or sodium thiosulfate, and the pH regulator is an acid solution. The ammonia inhibitor for livestock and poultry manure conversion process can significantly reduce the amount of ammonia generated, while promoting the growth of black soldier fly and improving the conversion efficiency. The present disclosure is suitable for the conversion treatment of livestock and poultry manure.

Description

Technical Field

[0001] This invention relates to the field of livestock and poultry manure treatment technology, and in particular to an ammonia inhibitor for the livestock and poultry manure conversion process and a method for manure conversion. Background Technology

[0002] With the rapid development of intensive livestock and poultry farming in my country, a large amount of livestock waste has been generated. The black soldier fly (S. spp.) is a saprophagous insect whose larvae are characterized by a wide range of diets, large appetites, and strong resilience. These larvae can feed on various organic wastes such as livestock and poultry manure and kitchen waste, transforming these wastes into their own bodies and excrement. Therefore, utilizing the black soldier fly to convert livestock and poultry manure has high economic and environmental value and has attracted widespread attention both domestically and internationally.

[0003] Currently, there are numerous domestic and international technological cases utilizing black soldier flies to convert and treat kitchen waste and livestock manure, and related technical equipment has been developed. However, during operation, it has been found that the large amount of ammonia generated during the black soldier fly treatment of waste, especially livestock manure, seriously affects the breeding environment and reduces the efficiency of black soldier fly treatment of livestock manure. Furthermore, the presence of large amounts of ammonia corrodes intelligent equipment systems, reducing their service life. Therefore, researching the ammonia generation mechanism during the black soldier fly conversion of livestock manure and reducing ammonia production through regulation is of great significance for the development of the intelligent black soldier fly treatment industry for livestock manure. Summary of the Invention

[0004] This invention provides an ammonia inhibitor for the conversion process of livestock and poultry manure. By adding the ammonia inhibitor of this invention to livestock and poultry manure, the ammonia emissions of black soldier flies during the manure conversion process can be reduced, while promoting the growth of black soldier flies and improving the conversion efficiency of livestock and poultry manure by black soldier flies.

[0005] This invention provides an ammonia inhibitor for the black soldier fly larvae's process of converting manure, comprising a metabolic inhibitor and a pH adjuster. The amount of the pH adjuster is such that the metabolic inhibitor inhibits ammonia production during the black soldier fly larvae's manure conversion process at a pH of 4-5.

[0006] In this invention, the metabolic inhibitor is copper sulfate or sodium thiosulfate.

[0007] The pH adjuster is any one of hydrochloric acid solution, sulfuric acid solution, and acetic acid solution.

[0008] Furthermore, based on the dry basis of livestock and poultry manure, the dosage of copper sulfate is 400-600 mg / kg; the dosage of sodium thiosulfate is 500-1000 mg / kg; and the dosage of pH adjuster is to adjust the pH value of livestock and poultry manure to 4-5.

[0009] On the other hand, the present invention provides the application of an ammonia inhibitor in the conversion process of livestock and poultry manure.

[0010] On the other hand, the present invention provides a method for converting livestock and poultry manure, comprising the following steps:

[0011] (1) Add metabolic inhibitors to fresh livestock and poultry manure.

[0012] (2) Add a pH adjuster to fresh livestock and poultry manure to adjust the pH value of the manure to 4-5;

[0013] (3) Black soldier fly larvae are introduced into fresh livestock and poultry manure for feeding.

[0014] The metabolic inhibitor mentioned in step (1) above can be either copper sulfate or sodium thiosulfate.

[0015] Furthermore, the amount of copper sulfate added relative to the dry basis of feces is 400-600 mg / kg; the amount of sodium thiosulfate added relative to the dry basis of feces is 500-1000 mg / kg.

[0016] Furthermore, the pH adjuster mentioned in step (2) above is any one of sulfuric acid solution, hydrochloric acid solution, and acetic acid solution.

[0017] The moisture content of the fresh livestock and poultry manure described in steps (1)-(3) above is 65%-75%.

[0018] The technical solution of this invention has the following advantages:

[0019] (1) Current technologies primarily reduce ammonia emissions during the bioconversion process of black soldier fly larvae by adjusting the protein-to-energy ratio of organic waste, increasing the moisture content and carbon-to-nitrogen ratio of the waste, and adding lactic acid. This invention provides an ammonia inhibitor that can suppress ammonia production during protein metabolism in the intestines of black soldier flies. This invention is the first to discover that copper sulfate and sodium thiosulfate can effectively inhibit ammonia production during protein metabolism in the intestines of black soldier flies under acidic conditions, thereby reducing ammonia production during the conversion of livestock and poultry manure by black soldier flies. Under suitable pH conditions, copper sulfate and sodium thiosulfate can reduce ammonia production during the bioconversion process by black soldier flies by up to 70.3% and 45.4%, respectively. The reduction in ammonia emissions can improve the breeding environment, reduce environmental pollution, reduce corrosion of intelligent equipment systems, and promote the industrialization of black soldier fly larvae for the conversion and treatment of livestock and poultry manure.

[0020] (2) In an acidic environment, copper sulfate and sodium thiosulfate not only inhibit the production of ammonia by black soldier flies in the bioconversion of livestock and poultry manure, but also promote the growth of black soldier flies, thereby further improving the conversion efficiency of black soldier flies in livestock and poultry manure. Under suitable copper sulfate content and pH conditions, the weight of black soldier flies can increase by more than 5.6%, and the manure conversion rate can reach more than 14%. Under suitable sodium thiosulfate content and pH conditions, the weight of black soldier flies can increase by more than 2.8%, and the manure conversion rate can reach more than 13%. Attached Figure Description

[0021] Figure 1 The graph shows the ammonia production of fresh chicken manure by black soldier fly biotransformation under different copper sulfate concentrations at pH 4.2. In the graph, CKO represents the ammonia production of fresh chicken manure without black soldier fly and ammonia inhibitor in 10 days; CK represents the ammonia production of fresh chicken manure with only black soldier fly added and no ammonia inhibitor added in 10 days; copper sulfate 300, 400, 500, 600, and 700 represent the ammonia production of fresh chicken manure with 300, 400, 500, 600, and 700 mg / kg of copper sulfate (based on dry manure) added respectively, then adjusted to pH 4.2, and black soldier fly added for biotransformation in 10 days.

[0022] Figure 2 The graph shows the ammonia production at different pH values ​​under a copper sulfate concentration of 500 mg / kg (based on dry manure). CK represents the ammonia production in fresh chicken manure within 10 days when only black soldier flies are added without ammonia inhibitors. pH3, pH4, pH5, and pH6 represent the ammonia production within 10 days when 500 mg / kg copper sulfate (based on dry manure) is added to fresh chicken manure, the pH is adjusted to 3, 4, 5, and 6 respectively with acid solution, and then black soldier flies are added for bioconversion.

[0023] Figure 3 The graph shows the ammonia production of fresh chicken manure by black soldier fly biotransformation under different sodium thiosulfate concentrations at pH 4.4. In the graph, CKO represents the ammonia production of fresh chicken manure without black soldier fly and ammonia inhibitor in 10 days; CK represents the ammonia production of fresh chicken manure with only black soldier fly added and no ammonia inhibitor added in 10 days; sodium thiosulfate 300, 500, 700, 1000, and 1200 represent the ammonia production of fresh chicken manure after adding 300, 500, 700, 1000, and 1200 mg / kg of sodium thiosulfate (based on dry manure basis) to fresh chicken manure, adjusting the pH to 4.4, and then adding black soldier fly for biotransformation in 10 days.

[0024] Figure 4The graph shows the ammonia production at different pH values ​​under a sodium thiosulfate concentration of 500 mg / kg (based on dry manure). CK represents the ammonia production in fresh chicken manure within 10 days when only black soldier flies are added without ammonia inhibitors. pH3, pH4, pH5, and pH6 represent the ammonia production within 10 days when 500 mg / kg sodium thiosulfate (based on dry manure) is added to fresh chicken manure, the pH is adjusted to 3, 4, 5, and 6 respectively with acid solution, and then black soldier flies are added for bioconversion. Detailed Implementation

[0025] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0026] Example 1

[0027] Five 5kg portions of fresh chicken manure with a moisture content of 68% were weighed out. 480, 640, 800, 960, and 1120 mg of analytical grade copper sulfate were added to each portion of fresh chicken manure (the amount of copper sulfate added relative to the dry basis of the manure was 300, 400, 500, 600, and 700 mg / kg, respectively), and the mixture was stirred thoroughly. A 10% sulfuric acid solution was then added to each portion of fresh chicken manure to adjust the pH to 4.2. An equal amount of chicken manure was used as a control (CK), with a sample containing only sulfuric acid and the same amount of water. The prepared samples were stored at low temperature and thawed before feeding.

[0028] Example 2

[0029] Take four portions of fresh chicken manure with a moisture content of 68%, each weighing 5 kg. Add 800 mg of copper sulfate to each portion of fresh chicken manure (at this point, the amount of copper sulfate added is 500 mg / kg relative to the dry basis of the manure). Continue to add acetic acid solution to the four portions of fresh chicken manure to adjust the pH value to 3, 4, 5, and 6 respectively.

[0030] Example 3

[0031] Five 5kg portions of fresh chicken manure with a moisture content of 68% were taken. 480, 800, 1120, 1600, and 1920 mg of analytical grade sodium thiosulfate were added to each portion of fresh chicken manure (the amounts of sodium thiosulfate added relative to the dry basis of the manure were 300, 500, 700, 1000, and 1200 mg / kg, respectively). A 10% sulfuric acid solution was then added to each portion of fresh manure to adjust the pH to 4.4. An equal amount of chicken manure was taken as a control (CK), with the same amount of water and sulfuric acid added as the control. The prepared samples were then stored at low temperature.

[0032] Example 4

[0033] Weigh out 5 kg of fresh chicken manure with a moisture content of 68% and add 800 mg of sodium thiosulfate to each of the four portions (at this point, the amount of sodium thiosulfate added is 500 mg / kg relative to the dry basis of the manure). Continue to add hydrochloric acid to the four portions of fresh chicken manure to adjust the pH value to 3, 4, 5, and 6 respectively.

[0034] Example 5: Determination of ammonia production during the black soldier fly biotransformation process

[0035] Take 20g of each of the chicken manure substrates from Examples 1-4 and spread them evenly in a plastic box (L×W×H: 26cm×15cm×13cm). Then, inoculate each box with 2g (about 800) of 7-day-old black soldier fly larvae (the larvae are about 0.8cm long). At the same time, place the same amount of chicken manure in the plastic box without black soldier flies as a control (CK0). Each group has three replicates. Feed the same amount of chicken manure once a day for 10 days. After feeding, stop feeding and let it sit for 24 hours to allow the feces in the larvae's intestines to be completely expelled. Then, separate the larvae and feces and weigh them. Place the feeding device in a large-capacity plastic box (L×W×H: 67cm×41.5cm×16.5cm). Seal the large plastic box with plastic wrap. During the breeding period, use a multi-functional portable gas detector to measure the ammonia concentration at regular intervals every day. After the measurement, open the sealing film, ventilate for half an hour, and then reseal it.

[0036] Results statistics:

[0037] Depend on Figure 1 It is evident that a large amount of ammonia was generated during the conversion of chicken manure by black soldier flies. Compared to treatment without black soldier flies, the cumulative ammonia production over 10 days increased by 4.8 times. The addition of sulfuric acid and copper sulfate of different concentrations reduced ammonia production by 25.3-70.3%, and ammonia production decreased with increasing copper sulfate concentration. The addition of copper sulfate at a concentration of 300-600 mg / kg increased the biomass of fresh black soldier flies and improved the conversion rate of chicken manure (see Table 1), while the addition of copper sulfate at a concentration of 800 mg / kg reduced the weight of fresh black soldier flies and decreased the conversion rate of chicken manure. Considering ammonia, black soldier fly biomass, and conversion rate, a copper sulfate concentration of 400-600 mg / kg is recommended as the optimal dosage for suppressing ammonia during the conversion of chicken manure by black soldier flies.

[0038] Depend on Figure 2It is evident that at a copper sulfate concentration of 500 mg / kg, the cumulative ammonia production over 10 days decreased by 36.9-67.5% as the pH of the material decreased. Specifically, ammonia production decreased by 36.9% at pH 6, and by 60.7-67.5% at pH 3-5. However, at pH 3, the excessive acidity may have inhibited the growth of black soldier flies, significantly reducing their biomass and chicken manure conversion rate (see Table 1). At pH 4-6, both the biomass and conversion rate of black soldier flies were higher than the control (CK). Considering ammonia production, black soldier fly biomass, and conversion rate, a pH of 4-5 is recommended as the optimal acidity adjustment range for black soldier fly conversion of chicken manure.

[0039] Depend on Figure 3 It is evident that the addition of sulfuric acid and sodium thiosulfate at different concentrations reduced the cumulative ammonia production over 10 days by 21.7-43.2%, with the ammonia production decreasing as the concentration of sodium thiosulfate increased. At a sodium thiosulfate concentration of 300 mg / kg, ammonia production decreased by 21.7%, while at 500 mg / kg, the decrease was 33.6%. Sodium thiosulfate concentrations of 300-1000 mg / kg had no significant effect on black soldier fly growth or chicken manure conversion rate. However, at a concentration of 1200 mg / kg, it significantly reduced black soldier fly biomass and chicken manure conversion rate (see Table 2). Considering ammonia levels, black soldier fly biomass, and conversion rate, a sodium thiosulfate concentration of 500-1000 mg / kg is recommended as the optimal dosage for suppressing ammonia production during black soldier fly conversion of chicken manure.

[0040] Depend on Figure 4 It is evident that with a sodium thiosulfate concentration of 500 mg / kg, the cumulative ammonia production over 10 days decreased by 24.9-45.4% as the pH of the material decreased. Specifically, ammonia production decreased by 24.9% at pH 6, and by 34.2-45.4% at pH 3-5. However, at pH 3, the excessive acidity may have inhibited the growth of black soldier flies, significantly reducing their biomass and chicken manure conversion rate (see Table 2). At pH 4-6, there were no significant differences in black soldier fly biomass and conversion rate compared to the control (CK). Considering ammonia levels, black soldier fly biomass, and conversion rate, a pH range of 4-5 is recommended as the optimal acidity adjustment range for black soldier fly conversion of chicken manure.

[0041] Table 1. Effects of different copper sulfate concentrations and pH on the neutralization and conversion rate of fresh black soldier fly larvae.

[0042]

[0043] Note: Different letters in the same column of the table indicate significant differences at the 0.05 level.

[0044] Table 2. Effects of different sodium thiosulfate concentrations and pH on the neutralization and conversion rate of fresh black soldier fly larvae.

[0045]

[0046] Note: Different letters in the same column of the table indicate significant differences at the 0.05 level.

[0047] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An ammonia inhibitor for the conversion process of livestock and poultry manure, characterized in that, It consists of a metabolic inhibitor and a pH adjuster. The metabolic inhibitor inhibits ammonia production during the conversion of livestock and poultry manure by black soldier flies under pH 4-5 conditions. The metabolic inhibitor is copper sulfate or sodium thiosulfate.

2. The ammonia inhibitor according to claim 1, characterized in that, The pH adjuster is any one of hydrochloric acid solution, sulfuric acid solution, and acetic acid solution.

3. The application of the ammonia inhibitor as described in any one of claims 1-2 in the conversion of livestock and poultry manure.

4. A method for converting livestock and poultry manure based on the ammonia inhibitor according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Add metabolic inhibitors to fresh livestock and poultry manure; (2) Then add a pH adjuster to adjust the pH of the system to 4-5; (3) Then, black soldier fly larvae are introduced for rearing.

5. A method for converting livestock and poultry manure according to claim 4, characterized in that, The metabolic inhibitor mentioned in step (1) is copper sulfate or sodium thiosulfate.

6. The method for converting livestock and poultry manure according to claim 5, characterized in that, The amount of copper sulfate added is 400-600 mg / kg relative to the dry basis of feces.

7. A method for converting livestock and poultry manure according to claim 5, characterized in that, The amount of sodium thiosulfate added is 500-1000 mg / kg relative to the dry basis of feces.

8. A method for converting livestock and poultry manure according to claim 4, characterized in that, The pH adjuster mentioned in step (2) is any one of hydrochloric acid solution, sulfuric acid solution, or acetic acid solution.

9. A method for converting livestock and poultry manure according to claim 4, characterized in that, The moisture content of the fresh livestock and poultry manure is 65%-75%.

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