Vegetable waste accelerator for improving removal rate of natural estrogen in anaerobic fermentation of cow dung and application thereof

Abstract

This invention relates to the field of new pollutant removal technology from livestock and poultry manure, and particularly to a vegetable waste promoter and its application for improving the removal rate of natural estrogens during anaerobic fermentation of cow manure. The vegetable waste promoter provided by this invention comprises a dry material; the dry material is obtained by drying a mixture of vegetable waste and iron salts at a temperature of 600-800℃; the mass ratio of vegetable waste to iron salts, based on dry weight, is 8-12:1. Adding this vegetable waste promoter to the anaerobic fermentation of cow manure can significantly improve the removal rate of estrogen, while simultaneously increasing the treatment efficiency of agricultural waste and achieving high-value utilization of vegetable waste.

Description

Technical Field

[0001] This invention relates to the field of new pollutant removal technology for livestock and poultry manure, and in particular to a vegetable waste promoter that improves the removal rate of natural estrogens from anaerobic fermentation of cow manure and its application. Background Technology

[0002] Endocrine-disrupting chemicals carried in livestock and poultry manure are a major environmental concern and a significant challenge for treatment. Estrogens are considered the most typical example of such chemicals. Dairy farming has been identified as a significant source of natural estrogens (such as estrone E1, estradiol E2, and estriol E3) released into the environment. These natural estrogens are secreted by cattle and excreted in their feces, with levels ranging from approximately 21.8 to 101.0 μg / kg. Even at extremely low concentrations, these estrogens can disrupt the endocrine systems of various freshwater species, negatively impacting their reproduction and development. Converting and removing these natural estrogens before they enter the environment is one effective method to reduce this pollution.

[0003] Among existing livestock and poultry manure treatment technologies, anaerobic fermentation is widely used due to its dual environmental and energy benefits. However, estrogens are generally considered persistent under anaerobic conditions. These hormones may accumulate in anaerobic or hypoxic environments, and their metabolites can be converted into parent estrogens under certain conditions, resulting in negative removal rates. Previous studies have investigated the removal efficiency of natural estrogens in cow manure during anaerobic fermentation, but they only found interconversion between estrogens; the total hormone concentration did not decrease significantly. Furthermore, in anaerobic treatment facilities in dairy farms in East China, the total estrogen removal efficiency was only 14.7%.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a vegetable waste promoter that enhances the removal rate of natural estrogens from anaerobic fermentation of cow manure and its application, which can improve the removal effect of natural estrogens in anaerobic fermented cow manure.

[0006] Specifically, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a vegetable waste promoter for improving the removal rate of natural estrogens from anaerobic fermentation of cow manure, comprising a dry material; the dry material is obtained by drying a mixture of vegetable waste and iron salt at a temperature of 600-800°C; the mass ratio of the vegetable waste to the iron salt, based on dry weight, is 8-12:1, preferably 10:1.

[0008] This invention utilizes vegetable waste to prepare an accelerator. Adding this accelerator to the anaerobic fermentation of cow manure can improve the estrogen removal rate, thereby achieving high-value utilization of vegetable waste and improving the treatment efficiency of agricultural waste such as cow manure.

[0009] Preferably, the vegetable waste is selected from the seedlings of solanaceous vegetables.

[0010] Preferably, the particle size of the vegetable waste is 1-2 cm.

[0011] Preferably, the drying process further includes a pulverizing step, wherein the pulverization is to pass through an 80±20 mesh sieve.

[0012] Preferably, the iron salt is FeCl3.

[0013] Preferably, the vegetable waste promoter further includes a wet material; the wet material is prepared by crushing vegetable waste to a particle size of 0.5±0.3cm. The wet material itself has a high content of functional genes for the biodegradation and metabolism of exogenous chemicals, and can promote the growth of estrogen-degrading bacteria, including iron-reducing bacteria; when combined with dry material, it can significantly improve the utilization rate of estrogen in cow manure by estrogen-degrading bacteria, increasing the estrogen removal rate in anaerobic fermentation of cow manure from a maximum of negative value to 68.63%.

[0014] Secondly, the present invention provides the application of the vegetable waste promoter in the anaerobic fermentation of cow manure.

[0015] Preferably, the application includes: using the vegetable waste promoter to improve the removal rate of natural estrogens from the anaerobic fermentation of cow manure.

[0016] More preferably, in the anaerobic fermentation system of cow manure, the mixing ratio of cow manure and wet material is 4:2-4 based on the volatile solids concentration, and more preferably 4:3.

[0017] More preferably, in the anaerobic fermentation system of cow manure, the amount of dry material added is 3%-8% of the total solid content of cow manure and wet material.

[0018] In a more specific embodiment of the present invention, a method for enhancing estrogen removal through anaerobic fermentation of cow manure using dry / wet vegetable waste as a promoter is provided. Fresh vegetable waste, preferably tomato vines (a type of eggplant), is selected as the dry promoter material. The waste is pulverized to a particle size of 1-2 cm and dried at 105°C for 24 hours. Iron salt, preferably FeCl3, is selected and weighed at a ratio of vegetable waste to iron salt of 10:1. The solution is dissolved in water and sprayed onto the surface of the vegetable waste, continuously stirred until the raw materials and iron salt are evenly mixed. The mixed material is placed in a muffle furnace at a temperature of 600-800°C, preferably 800°C, and the dry promoter material is ground through an 80-mesh sieve for later use. Fresh vegetable waste, preferably leafy vegetable waste, is selected as the wet promoter material, pulverized to a particle size of less than 1 cm, preferably 0.5 cm. The cow dung and wet accelerator are mixed in a volatile solids ratio of 4:2-4:4, preferably 4:3, and then added to the anaerobic digester. Simultaneously, 3%-8% (preferably 4%) of dry accelerator material is added, based on the total solids content of the cow dung and wet accelerator material. Anaerobic fermentation is carried out at 35±1℃ until gas production is completely finished.

[0019] Beneficial effects

[0020] This invention provides a vegetable waste promoter for improving the removal rate of natural estrogens during the anaerobic fermentation of cow manure and its application. By adding the vegetable waste promoter provided by this invention to the anaerobic fermentation of cow manure, the removal rate of estrogen can be significantly improved, thereby increasing the treatment efficiency of agricultural waste and achieving high-value utilization of vegetable waste. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be described below.

[0022] Figure 1 The results show the relative abundance of estrogen-degrading bacteria in the various embodiments and comparative examples of this invention. Detailed Implementation

[0023] This invention addresses the problem of poor estrogen removal during anaerobic fermentation of cow manure, providing a vegetable waste promoter and fermentation process to enhance the removal of natural estrogen from cow manure during anaerobic fermentation. Using the vegetable waste provided by this invention as a promoter significantly improves the removal of natural estrogen from anaerobic fermented cow manure.

[0024] In a more specific embodiment provided by the present invention, the preparation method of the vegetable waste accelerator is as follows:

[0025] (1) Select fresh vegetable waste and crush it.

[0026] (2) Dry material preparation: Dry the crushed vegetable waste, and then mix it with iron salt in a certain proportion. Dissolve the iron salt in water and spray it onto the vegetable raw material. Stir continuously until the mixture is uniform. Put the mixed material into a muffle furnace to prepare dry material. Grind the prepared dry material through an 80-mesh sieve for later use.

[0027] (3) Preparation of wet materials: Crush fresh vegetable waste, test the dry matter concentration and volatile solids concentration, and set aside for later use.

[0028] More preferably, the particle size range of the pulverized material in process (1) is 1cm-2cm.

[0029] More preferably, the drying temperature in process (2) is 105°C and the drying time is 24 hours.

[0030] More preferably, the dry material in process (2) can be various vegetable wastes, preferably tomato seedlings of the eggplant and solanaceous variety.

[0031] More preferably, the iron salt in process (2) can be Fe2(SO4)3, FeCl3, etc., and FeCl3 is preferred.

[0032] More preferably, the ratio in process (2) is vegetable waste: iron salt = 10:1.

[0033] More preferably, the preparation temperature in process (2) is 600-800℃, preferably 800℃.

[0034] More preferably, the wet material in process (3) can be various kinds of vegetable waste, preferably leafy vegetable waste.

[0035] More preferably, the particle size of the pulverized material in process (3) is less than 1 cm, preferably 0.5 ± 0.3 cm, and more preferably 0.5 cm.

[0036] In a more specific embodiment provided by the present invention, the method for anaerobic fermentation of cow manure by adding an exogenous vegetable waste promoter is as follows:

[0037] (4) Anaerobic fermentation: Cow manure, wet material and dry material are mixed in a certain proportion, added to the anaerobic fermentation device, mixed evenly and placed at a certain temperature for anaerobic fermentation.

[0038] More preferably, the ratio of cow dung to wet accelerator in process (4) is 4:2-4:4 (based on volatile solids concentration), preferably 4:3.

[0039] Furthermore, in process (4), the amount of dry accelerator added is 3%-8% of the total solid content of cow dung and wet accelerator in the reactor, preferably 4%.

[0040] Furthermore, the fermentation temperature in process (4) is 35±1℃.

[0041] Furthermore, in process (4), fermentation continues until the reactor produces gas completely.

[0042] Furthermore, the natural estrogen is the sum of estrone E1, estradiol E2, and estriol E3.

[0043] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the embodiments are all conventional methods; the materials and reagents used are all commercially available.

[0044] Example 1

[0045] This embodiment provides a method for enhancing estrogen removal through anaerobic fermentation of cow manure using dry / wet vegetable waste as a promoter, including the following steps:

[0046] (1) Processing of raw materials for accelerator: The accelerator consists of two parts, dry material and wet material. Tomato seedlings of solanaceous type are selected, crushed to 1cm-2cm and dried at 105℃ for 24 hours to prepare dry material. Waste of leafy vegetable type is selected, crushed to a particle size of 0.5cm and used as wet material.

[0047] (2) Preparation of dry material: Mix the crushed and dried tomato seedlings with FeCl3 at a ratio of 10:1. Dissolve FeCl3 in water and spray it onto the raw material. Stir continuously until the mixture is uniform. Put the mixed material into an 800℃ muffle furnace to prepare dry material. Grind the prepared dry material through an 80-mesh sieve for later use.

[0048] (3) Preparation of wet materials: Fresh leafy vegetable waste is crushed to a particle size of 0.5 cm, and the dry matter concentration and volatile solids concentration are tested for later use.

[0049] (4) Anaerobic fermentation: Mix cow manure and wet accelerator in a ratio of 4:3 (based on volatile solids concentration); mix dry accelerator in a ratio of 4% of the total solids content of cow manure and wet accelerator, add to the anaerobic fermentation device, mix well and place at 35±1℃ for anaerobic fermentation until gas production ends.

[0050] Example 2

[0051] This embodiment provides a method for enhancing estrogen removal through anaerobic fermentation of cow manure using dry / wet vegetable waste as a promoter, including the following steps:

[0052] (1) Processing of raw materials for accelerator: The accelerator consists of two parts, dry material and wet material. Tomato seedlings of solanaceous type are selected, crushed to 1cm-2cm and dried at 105℃ for 24 hours to prepare dry material. Waste of leafy vegetable type is selected, crushed to a particle size of 0.5cm and used as wet material.

[0053] (2) Preparation of dry material: Mix the crushed and dried tomato seedlings with FeCl3 at a ratio of 10:1. Dissolve FeCl3 in water and spray it onto the raw material. Stir continuously until the mixture is uniform. Put the mixed material into an 800℃ muffle furnace to prepare dry material. Grind the prepared dry material through an 80-mesh sieve for later use.

[0054] (3) Preparation of wet materials: Fresh leafy vegetable waste is crushed to a particle size of 0.5 cm, and the dry matter concentration and volatile solids concentration are tested for later use.

[0055] (4) Anaerobic fermentation: Mix cow manure and wet accelerator in a ratio of 4:3 (based on volatile solids concentration); mix dry accelerator in a ratio of 8% of the total solids content of cow manure and wet accelerator, add to the anaerobic fermentation device, mix well and place at 35±1℃ for anaerobic fermentation until gas production ends.

[0056] Example 3

[0057] This embodiment provides a method for enhancing estrogen removal through anaerobic fermentation of cow manure using dry / wet vegetable waste as a promoter, including the following steps:

[0058] (1) Processing of raw materials for accelerator: The accelerator consists of two parts, dry material and wet material. Tomato seedlings of solanaceous type are selected, crushed to 1cm-2cm and dried at 105℃ for 24 hours to prepare dry material. Waste of leafy vegetable type is selected, crushed to a particle size of 0.5cm and used as wet material.

[0059] (2) Preparation of dry material: Mix the crushed and dried tomato seedlings with FeCl3 at a ratio of 10:1. Dissolve FeCl3 in water and spray it onto the raw material. Stir continuously until the mixture is uniform. Put the mixed material into an 800℃ muffle furnace to prepare dry material. Grind the prepared dry material through an 80-mesh sieve for later use.

[0060] (3) Preparation of wet materials: Fresh leafy vegetable waste is crushed to a particle size of 0.5 cm, and the dry matter concentration and volatile solids concentration are tested for later use.

[0061] (4) Anaerobic fermentation: Mix cow manure and wet accelerator in a ratio of 4:3 (based on volatile solids concentration); mix dry accelerator in a ratio of 6% of the total solids content of cow manure and wet accelerator, add to the anaerobic fermentation device, mix well and place at 35±1℃ for anaerobic fermentation until gas production ends.

[0062] Example 4

[0063] This embodiment provides a method for enhancing estrogen removal through anaerobic fermentation of cow manure using dry / wet vegetable waste as a promoter, including the following steps:

[0064] (1) Processing of raw materials for accelerator: The accelerator consists of two parts, dry material and wet material. Tomato seedlings of solanaceous type are selected, crushed to 1cm-2cm and dried at 105℃ for 24 hours to prepare dry material. Waste of leafy vegetable type is selected, crushed to a particle size of 0.5cm and used as wet material.

[0065] (2) Preparation of dry material: Mix the crushed and dried tomato seedlings with FeCl3 at a ratio of 10:1. Dissolve FeCl3 in water and spray it onto the raw material. Stir continuously until the mixture is uniform. Put the mixed material into a muffle furnace at 700℃ to prepare dry material. Grind the prepared dry material through an 80-mesh sieve for later use.

[0066] (3) Preparation of wet materials: Fresh leafy vegetable waste is crushed to a particle size of 0.5 cm, and the dry matter concentration and volatile solids concentration are tested for later use.

[0067] (4) Anaerobic fermentation: Mix cow manure and wet accelerator in a ratio of 4:3 (based on volatile solids concentration); mix dry accelerator in a ratio of 4% of the total solids content of cow manure and wet accelerator, add to the anaerobic fermentation device, mix well and place at 35±1℃ for anaerobic fermentation until gas production ends.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that only wet material was added during the anaerobic fermentation of cow manure, and no dry material was added. In this comparative example, cow manure and wet material were also mixed in a 4:3 ratio (based on volatile solids concentration), added to the anaerobic fermentation device, mixed well, and placed at 35±1℃ for anaerobic fermentation until gas production ended.

[0070] Comparative Example 2

[0071] Compared to Comparative Example 1, this comparative example also involved adding only wet material, without adding dry material, during the anaerobic fermentation of cow manure. The difference lies in the following: in this comparative example, cow manure and wet material were mixed in a 4:4 ratio (based on volatile solids concentration), added to the anaerobic fermentation device, mixed thoroughly, and placed at 35±1℃ for anaerobic fermentation until gas production ceased.

[0072] Comparative Example 3

[0073] Compared to Comparative Example 1, this comparative example also involved adding only wet material, without adding dry material, during the anaerobic fermentation of cow manure. The difference lies in the following: in this comparative example, cow manure and wet material were mixed at a ratio of 4:1 (based on volatile solids concentration), added to the anaerobic fermentation device, mixed thoroughly, and placed at 35±1℃ for anaerobic fermentation until gas production ceased.

[0074] Comparative Example 4

[0075] This comparative example does not add any accelerators. The cow manure is directly added to the anaerobic fermentation device and anaerobic fermented at 35±1℃ until gas production ends.

[0076] The comparison of anaerobic fermentation parameters between the various embodiments and comparative examples is shown in Table 1 below:

[0077] Table 1. Comparison of anaerobic fermentation parameters between the various examples and comparative examples.

[0078]

[0079] The data above shows that using dry / wet vegetable waste as a promoter can effectively improve the removal rate of total estrogen in the anaerobic fermentation of cow manure.

[0080] In addition, the relative abundance of estrogen degradation-related bacteria in each experimental group was determined, and the results are shown in [see figure]. Figure 1 .Depend on Figure 1 As shown in Table 1, the wet vegetable waste promoter provided by this invention can promote the removal of estrogen in the anaerobic cow manure system by promoting the growth of bacteria related to estrogen degradation. Although the addition of dry material under certain conditions reduces the relative abundance of bacteria related to estrogen degradation, the dry material can significantly promote the adsorption of estrogen onto it, thereby greatly improving the utilization rate of estrogen by bacteria related to estrogen degradation. In particular, the 4% dry material added in Example 1 has the strongest effect on improving the utilization rate of estrogen by bacteria related to estrogen degradation, and the best effect on improving the removal rate of total natural estrogen. In addition, the wet material itself has a high content of functional genes for the biodegradation and metabolism of exogenous chemicals. Adding it to the anaerobic fermentation of cow manure can increase the richness of these functional genes in the system, which is beneficial to promoting the degradation and metabolism of natural estrogen.

[0081] The embodiments described above are merely illustrative of several implementations of the present invention, designed to facilitate a detailed understanding of the technical solutions of the present invention, but should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A vegetable waste promoter that enhances the removal rate of natural estrogens during anaerobic fermentation of cow manure, characterized in that, Includes dry material; the dry material is obtained by drying a mixture of vegetable waste and iron salt at a temperature of 600-800℃; the mass ratio of vegetable waste to iron salt, based on dry weight, is 8-12:1; It also includes wet materials; the wet materials are made by crushing vegetable waste to a particle size of 0.5±0.3cm, and they have a high content of functional genes for the biodegradation and metabolism of exogenous chemicals, and can promote the growth of estrogen-degrading bacteria, including iron-reducing bacteria. In the aforementioned anaerobic fermentation system for cow manure, the mixing ratio of cow manure and wet material is 4:2-4 based on the volatile solids concentration. In the aforementioned anaerobic fermentation system for cow manure, the amount of dry material added is 3%-8% of the total solid content of cow manure and wet material.

2. The vegetable waste accelerator according to claim 1, characterized in that, The vegetable waste in the dry raw materials is selected from the seedlings of solanaceous vegetables.

3. The vegetable waste accelerator according to claim 1 or 2, characterized in that, The particle size of the vegetable waste in the dry raw materials is 1-2 cm.

4. The vegetable waste accelerator according to claim 1 or 2, characterized in that, The drying process also includes a pulverizing step, wherein the pulverization is to pass through an 80±20 mesh sieve.

5. The vegetable waste accelerator according to claim 1 or 2, characterized in that, The iron salt is FeCl3.

6. The application of the vegetable waste promoter according to any one of claims 1-5 in the anaerobic fermentation of cow manure.

7. The application according to claim 6, characterized in that, The vegetable waste promoter was used to improve the removal rate of natural estrogens during the anaerobic fermentation of cow manure.

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