Efficient compound biochemical deodorant and preparation method thereof

Abstract

The invention discloses an efficient compound biochemical deodorant and a preparation method thereof, and belongs to the technical field of deodorization of livestock and poultry farms. The deodorant comprises a surfactant, an oxidizing agent, a metal ion activating agent, a biological chelating agent and a stabilizing agent. Wherein the surface active agent is formed by compounding a biological surface active agent and a synthetic surface active agent, so that the solubility of the hydrophobic VOCs can be increased; the oxidant is used for carrying out in-situ oxygenolysis on the captured malodorous substances, so that the problem of saturation failure of the deodorant is solved; the biological chelating agent not only can keep the high activity of the metal ion activating agent, but also avoids the problem of environmental residue of the traditional chemical chelating agent. The deodorant can be used for livestock and poultry breeding deodorization, can be directly sprayed or used as an additive to be added into existing environment-friendly equipment, is high in odor absorption capacity and good in biodegradability, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of deodorization technology for livestock and poultry farms, and relates to a highly efficient compound biochemical deodorizer and its preparation method. Background Technology

[0002] In recent years, the pig farming industry has been developing rapidly towards large-scale and intensive operations. However, with the expansion of farming scale, the odor pollution from pig farms and other livestock farms has become increasingly prominent, becoming a significant environmental factor restricting the industry's green and sustainable development and attracting widespread social attention. Pig farm exhaust gases are extremely complex, consisting of ammonia (NH3), hydrogen sulfide (H2S), particulate matter (PM), and hundreds of volatile organic compounds (VOCs). Among these, volatile fatty acids (VFAs), phenols, indoles, and volatile sulfur compounds (VSCs), although typically at very low concentrations (ppb level), have extremely low odor thresholds and are major contributors to the sensory experience of foul odors. This not only harms human and animal health but also poses a serious threat to the surrounding atmospheric environment.

[0003] To address the increasingly severe problem of odor pollution, current end-of-pipe waste gas treatment technologies for livestock and poultry farms mainly include physical adsorption, biological treatment, chemical scrubbing, and advanced oxidation technologies. Various deodorizing agents based on absorption, oxidation, and biological treatment have been developed, achieving good results in odor reduction applications in livestock and poultry farms. However, traditional deodorizing agents for livestock and poultry farms have the following problems: Pig farm waste gas contains a large amount of key odor-causing substances, such as dimethyl sulfide, dimethyl disulfide, phenols, and indoles. These substances are highly hydrophobic and poorly water-soluble, making them difficult to effectively capture and remove using traditional water washing or acid-base deodorizing agents. This results in unsatisfactory overall deodorization effects, with odors still easily escaping. During the washing process, the concentration of pollutants dissolved in the deodorizing agent continuously accumulates until saturation. This not only significantly reduces gas-liquid mass transfer efficiency, causing deodorization performance to decline significantly with prolonged operation, but also, if the saturated deodorizing agent is not replaced in time, the organic matter within it will decompose under the action of microorganisms, producing new odorous substances, causing secondary pollution, and increasing the burden and cost of wastewater treatment. Meanwhile, livestock and poultry production uses a large amount of chemically synthesized deodorizers, and their residues may impose a long-term burden on soil and water bodies. In particular, in the application of scrubbers, the discharge of circulating liquid increases the difficulty and cost of subsequent wastewater treatment, which does not meet the requirements of green development in animal husbandry.

[0004] To overcome the aforementioned shortcomings, researchers have improved deodorizing performance by adding additives to deodorizing liquids. Among these, adding surfactants is an effective way to increase the solubility of hydrophobic odorous substances. Existing technology has found that scientifically combining biosurfactants (such as rhamnolipids produced by Pseudomonas aeruginosa) with specific synthetic surfactants (such as Tween-80) can produce significant synergistic effects. Surfactant molecules with different structures can work together to more effectively reduce gas-liquid interfacial tension and form micellar structures, thereby increasing the solubilizing effect on different types of hydrophobic VOCs, resulting in better treatment performance than single components. Simultaneously, biosurfactants have the outstanding advantages of low toxicity and high biodegradability, and their application significantly improves the overall environmental compatibility of deodorants, effectively avoiding the secondary ecological risks caused by the residues of traditional chemical additives.

[0005] However, simply enhancing dissolution does not achieve fundamental degradation of pollutants, and the saturation problem of deodorizers remains. To address this issue, advanced oxidation technologies (AOPs) have been introduced into deodorizers, involving the addition of oxidants (such as sodium percarbonate) and activators (typically Fe). 2+ Under the catalysis of transition metal ions, strong oxidizing species such as hydroxyl radicals (·OH) are generated, which oxidize and decompose the captured malodorous substances in situ, thus regenerating the deodorant's ability to adsorb malodors.

[0006] Traditional advanced oxidation technologies, under the complex chemical environment and varying pH conditions of deodorants, easily cause metal ion activators to precipitate and become inactive, depositing on the surfaces of livestock and poultry facilities and causing pollution. While traditional synthetic chelating agents (such as EDTA) can stabilize metal ions, they are difficult to degrade themselves, easily causing persistent environmental pollution. Therefore, this invention provides an ideal solution using biological chelating agents (such as polypeptides and polysaccharides produced by microbial metabolism, such as Bacillus subtilis). These agents not only efficiently and stably complex metal ions, ensuring high activity of the activator under a wide range of operating conditions, but their excellent biodegradability also avoids the environmental residue problems of traditional chemical chelating agents, perfectly meeting the requirements of green chemical development. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of the existing technology by providing a formulation and preparation method for a highly efficient compound biochemical deodorant.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The biochemical deodorant of this invention comprises (by weight): 10-30 parts oxidant (sodium percarbonate or hydrogen peroxide, persulfate, etc.), 0.05-0.5 parts biosurfactant active ingredient (the active ingredient is a biological metabolite with chelating / solubilizing activity, such as rhamnolipid, surfactant, saponin, etc.), 0.01-0.12 parts synthetic surfactant (Tween-80, Tween-20, sodium dodecylbenzenesulfonate, sodium dodecyl sulfonate, Triton X-100, etc., cationic surfactants are prohibited), 0.5-3.0 parts biochelating agent active ingredient (metabolites of Bacillus subtilis), 0.2-0.7 parts activator, 1-5 parts stabilizer, and 80-150 parts water.

[0009] The activator's main components are FeSO4 (or transition metal salts such as CuSO4 and MnSO4), citric acid, and sodium citrate, with a mass ratio of 1:20:50. The preparation method involves adding 1 g of FeSO4, 20 g of citric acid, and 50 g of sodium citrate to 200 mL of distilled water, dissolving them to obtain the activator. The activator's function is to catalyze the stabilization of the oxidant to generate highly oxidizing free radicals.

[0010] The main components of the stabilizer are polyols, polyethers, polysaccharides or combinations thereof, preferably a mixture of glycerol and polyethylene glycol in a mass ratio of 1:1. Its main purpose is to stabilize various bioactive substances (biosurfactants, biochelating agents, enzymes, etc.), control the rate of free radical generation, reduce the damage of oxidants to bioactive substances, and provide long-lasting deodorization.

[0011] The effective components of the biosurfactant are calculated using one of the following methods: rhamnolipids: the rhamnosine (Rha) content is determined by orcinol colorimetric method, and the total rhamnolipid content = rhamnosine content × 2.5; surfactants: quantified by HPLC (205 nm) or LC-MS; saponins: quantified by vanillin-sulfuric acid method or HPLC. Wherein, the effective concentration of the biosurfactant when the biochemical deodorant is diluted to the working solution is: rhamnolipids 50-500 mg / L, or surfactants 20-200 mg / L, or saponins 0.1-2.0 g / L.

[0012] The present invention has the following beneficial effects: (1) The deodorizer of the present invention reduces the gas-liquid partition coefficient of odor-causing VOCs by compounding surfactants, and significantly improves the absorption capacity of odor.

[0013] (2) In addition to the odor reduction pathways such as absorption and biodegradation of traditional deodorants, the deodorant of the present invention also couples an oxidant. The oxidant can work synergistically with the surfactant to deeply oxidize the malodorous substances (odor-causing VOCs, etc.) absorbed into the liquid phase while absorbing odor components, thus solving the problem of deodorant saturation failure.

[0014] (3) The deodorant of the present invention uses a biological chelating agent to maintain the high activity of the metal ion activator. The metabolites extracted from Bacillus subtilis in the present invention can effectively chelate Fe. 2+ Cu 2+ Mn 2+ It also avoids the persistent pollution problems that may occur with traditional chemical chelating agents.

[0015] (4) Compared with traditional deodorants, the deodorant of the present invention has good biodegradability of each component and does not produce harmful products during the degradation process.

[0016] (5) The deodorant of the present invention is a stable concentrated liquid that can be diluted and sprayed directly on the pig house environment, manure surface, etc. to suppress the generation of odor from the source; it can also be added as a high-efficiency additive to existing environmental protection equipment such as chemical scrubbers and spray towers to greatly improve the treatment efficiency of complex odors without modifying the hardware, and has strong engineering practicality and promotion value.

[0017] In summary, this product's formula is not simply a collection of ingredients, but rather a synergistic combination of components; the absence of any one component will lead to a significant decrease in effectiveness. This product can collaboratively solve multiple technical challenges, such as low mass transfer efficiency of hydrophobic materials, easy saturation of deodorants, unstable activation systems, and poor environmental compatibility, to achieve efficient, stable, long-lasting, and environmentally friendly removal of various complex malodorous waste gases from pig farms. Detailed Implementation

[0018] The following examples demonstrate the odor reduction effect of the deodorizing liquid of this invention on odor-causing VOCs when used in different aquaculture species and aquaculture facilities. Various VOCs were measured by tank sampling-gas chromatography-mass spectrometry, and three parallel samples were collected for each sample and the average was processed.

[0019] The compound biochemical deodorizer involved in this invention is suggested to contain 10-30 parts by weight of oxidant, 1-5 parts by weight of stabilizer, 80-150 parts by weight of distilled water, 20-80 parts by weight of biosurfactant fermentation broth (0.05-0.5% active ingredient), 10-30 parts by weight of biochelating agent fermentation broth (0.5-3.0% active ingredient), 0.2-0.7 parts by weight of activator, and 0.01-0.12 parts by weight of synthetic surfactant. The specific dosage should be determined based on the deodorization effect in production. The examples are for reference only.

[0020] The sources of the raw materials involved in this invention are as follows: sodium percarbonate is purchased from existing pure sodium percarbonate products; Tween-80 is purchased from existing pure Tween-80 products; sodium citrate is purchased from existing pure sodium citrate products; the biosurfactant is obtained through microbial culture, and the specific culture method is as follows: Pseudomonas aeruginosa, or one of the genera Bacillus subtilis, Pseudomonas, Candida, or Staphylotrichum, or a non-pathogenic alternative strain, is inoculated into the biosurfactant culture medium and cultured at 37 °C for 72 h with stirring at 200–300 rpm; aeration: 1.0 vvm, dissolved oxygen >20%. The supernatant is then centrifuged to obtain the biosurfactant product, which is quantified according to the orcinol method. Only products with an effective ingredient concentration ≥5 g / L are permitted for preparation.

[0021] The preparation method of the biosurfactant culture medium is as follows: Add 5 g of NaNO3, 1.25 g of KH2PO4, 1.5 g of K2HPO4, 0.5 g of MgSO4, 0.1 g of MnSO4, 0.05 g of FeSO4, 0.05 g of CaCl2, 60 g of soybean oil, and 1.5 g of yeast extract to every 1000 mL of distilled water. The culture medium is sterilized at 121 ℃ for 30 min.

[0022] Biological chelating agents are obtained through microbial culture, and the specific culture method is as follows: Culture method: Bacillus subtilis was inoculated into the chelating agent culture medium and cultured at 35 °C for 48 h. After centrifugation, the supernatant was collected to obtain the product of the biological chelating agent.

[0023] The chelating agent culture medium is prepared as follows: 0.1 g of FeSO4 and 0.05 g of CuSO4 are added to 1000 mL of LB culture medium, and the culture medium is sterilized at 121 °C for 30 min.

[0024] All of the above strains can be purchased from commercial channels. Among them, Pseudomonas aeruginosa was purchased from China National Research Institute of Food Fermentation Industries Co., Ltd., and its trade name is Pseudomonas aeruginosa. Bacillus subtilis was also purchased from China National Research Institute of Food Fermentation Industries Co., Ltd., and its trade name is Bacillus subtilis.

[0025] If commercially available pure products are used directly (instead of obtaining them through microbial culture), the deodorizing effect of the deodorizer of this invention may be reduced to some extent. The alternative commercially available pure product is: rhamnolipin 5 g / L, Tween-80 0.2 g / L, sodium percarbonate 20 g / L, FeSO4 / citric acid / sodium citrate activator at a ratio of 1:20:50 (total 0.5 g / L), stabilizer (glycerol / PEG 1:1) 2 g / L, with the remainder being water. Before use, dilute 10–100 times to the working solution, corresponding to 50–500 mg / L of rhamnolipin.

[0026] Example 1: For deodorizing the environment inside livestock and poultry houses, this embodiment dissolves 14.4 g of the oxidant sodium percarbonate in 100 mL of distilled water with continuous stirring at a stirring rate of <800 rpm until completely dissolved to prepare an oxidant solution. While continuously stirring, 1.5 g of stabilizer is added to the oxidant solution to ensure thorough mixing. While continuously stirring, 50 mL of the biosurfactant fermentation broth and 20 mL of the biochelating agent fermentation broth are added to the mixture and thoroughly mixed. Finally, while continuously stirring, 0.5 g of activator and 0.157 g of Tween-80 are added to the mixture, and distilled water is added to bring the volume to 1000 mL to obtain the spray-type deodorizing solution of Example 1.

[0027] Example 2: For deodorizing fecal waste, 28.8 g of the oxidant sodium percarbonate was dissolved in 100 mL of distilled water under continuous stirring at a stirring rate of <800 rpm until completely dissolved to prepare an oxidant solution. While continuously stirring, 1.5 g of stabilizer was added to the oxidant solution and mixed thoroughly. Then, while continuously stirring, 100 mL of the biosurfactant fermentation broth and 50 mL of the biochelating agent fermentation broth were added to the mixture and mixed thoroughly. Finally, while continuously stirring, 0.5 g of activator and 0.785 g of Tween-80 were added to the mixture, and distilled water was added to bring the volume to 1000 mL to obtain the deodorizing solution of Example 2.

[0028] Example 3: For end-point odor reduction in livestock and poultry deodorization areas, this embodiment dissolves 144.0 g of the oxidant sodium percarbonate in 1000 mL of distilled water under continuous stirring at a stirring rate of <800 rpm until completely dissolved to prepare an oxidant solution. While continuously stirring, 2.5 g of stabilizer is added to the oxidant solution to ensure thorough mixing. Then, while continuously stirring, 250 mL of the biosurfactant fermentation broth and 200 mL of the biochelating agent fermentation broth are added to the mixture and thoroughly mixed. Finally, while continuously stirring, 25 g of activator and 15.7 g of Tween-80 are added to the mixture, and distilled water is added to bring the volume to 1000 mL to obtain the deodorizing solution of Example 3.

[0029] Example 4: The spray deodorizing liquid described in Example 1 was sprayed in the middle of the pigsty, with a single spray volume of 200 mL. Spraying was done once every 12 hours, for a total of 5 sprays.

[0030] Example 5: The deodorizing liquid described in Example 2 was sprayed onto the surface of fresh pig manure. The amount of liquid sprayed at one time was 15% of the mass of the pig manure. The liquid was sprayed once every 24 hours, for a total of 5 sprays.

[0031] Example 6: The deodorizing liquid described in Example 3 was sprayed continuously into the deodorizing room of the pigsty at a rate of 0.02 L / min for 6 hours.

[0032] Example 7: The deodorizing liquid described in Example 3 was added to the circulating water of the chemical scrubber in the deodorizing room of the pigsty, 500 mL every 12 hours, for a total of 5 times.

[0033] Example 8: The spray deodorizing liquid described in Example 1 was sprayed in the middle of the enclosed chicken house. The amount of spraying was 100 mL per spray, and the spraying was repeated once every 6 hours for a total of 10 sprays.

[0034] Example 9: The deodorizing liquid described in Example 2 was sprayed into the anaerobic fermentation tank in the chicken farm manure treatment area. The amount of liquid sprayed at one time was 500 mL, and it was sprayed once every 12 hours for a total of 5 times.

[0035] Example 10: The spray-type deodorizing liquid described in Example 3 was sprayed continuously in the deodorizing area outside the enclosed chicken house at a spray rate of 0.025 L / min for 6 hours.

[0036] Comparative Example 1: The deodorizing liquid spray in Example 4 was replaced with a 0.1% wt sulfuric acid solution spray, with a single spray volume of 200 mL, sprayed once every 12 hours, for a total of 5 sprays.

[0037] Comparative Example 2: The deodorizing liquid in Example 5 was replaced with a 5% wt sulfuric acid solution, which was sprayed onto the surface of fresh pig manure. The amount of each spray was 15% of the mass of the pig manure, and the spraying was repeated every 24 hours for a total of 5 times.

[0038] Comparative Example 3: The deodorizing liquid in Example 6 was replaced with purified water, which was sprayed into the deodorizing room of the pigsty continuously at a rate of 0.02 L / min for 6 hours.

[0039] Comparative Example 4: The deodorizing liquid in Example 7 was replaced with sulfuric acid solution to make the overall pH of the circulating water 4, and the system was run continuously for 48 hours, with the pH adjusted to 4 every 12 hours during the period.

[0040] Comparative Example 5: Prepare the same deodorizing liquid as in Example 3, except that the oxidant sodium percarbonate in the formula is removed to obtain a deodorizing liquid without sodium percarbonate, and add it into the washing machine circulating water in the same manner as in Example 7.

[0041] Comparative Example 6: Prepare the same deodorizing liquid as in Example 3, except that the biosurfactant in the formula is removed to obtain a deodorizing liquid without biosurfactants, and add it into the washing machine circulating water in the same manner as in Example 7.

[0042] Comparative Example 7: Prepare the same deodorizing liquid as in Example 3, except that the surfactant Tween-80 in the formula is removed to obtain a deodorizing liquid without surfactant Tween-80, and add it into the washing machine circulating water in the same manner as in Example 7.

[0043] Comparative Example 8: Prepare the same deodorizing liquid as in Example 3, except that the bio-chelating agent in the formula is removed to obtain a deodorizing liquid without the bio-chelating agent, and add it into the washing machine circulating water in the same manner as in Example 7.

[0044] Comparative Example 9: Prepare the same deodorizing liquid as in Example 3, except that the activator in the formula is removed to obtain a deodorizing liquid without activator, and add it into the washing machine circulating water in the same way as in Example 7.

[0045] Comparative Example 10: Prepare the same deodorizing liquid as in Example 3, except that the volume of the formula is increased to 2000 mL, resulting in a deodorizing liquid with a concentration diluted to 1 / 2 of the original formula. Add this deodorizing liquid to the washing machine's circulating water in the same manner as in Example 7.

[0046] Comparative Example 11: Prepare the same deodorizing liquid as in Example 3, except that the volume of the formula is increased to 5000 mL, resulting in a deodorizing liquid with a concentration diluted to 1 / 5 of the original formula. Add this deodorizing liquid to the washing machine's circulating water in the same manner as in Example 7.

[0047] Comparative Example 11: The experimental environment was the same as in Example 8, except that the spray deodorizing liquid was replaced with spray distilled water.

[0048] Comparative Example 12: The experimental environment was the same as in Example 9, except that the spray deodorizing liquid was replaced with a 0.5% wt sulfuric acid solution.

[0049] Comparative Example 13: The experimental environment was the same as in Example 10, except that the spray deodorizing liquid was replaced with a commercially available biological deodorizing agent.

[0050] Table 1: Comparison of deodorization effects between Examples 4-10 and Comparative Examples 1-14

[0051] As shown in Table 1, the deodorizing effect achieved by the deodorizer prepared in the embodiments of the present invention is significantly better than that of sulfuric acid solution, purified water and a commercially available biological deodorizer. After removing the oxidant sodium percarbonate, biosurfactant, synthetic surfactant, biological chelating agent or activator in the formula, or after overall dilution and testing, the results showed that none of them could achieve the effect of the original formula, indicating that the formula of the present invention has a reasonable composition and the ratio is the optimal result.

[0052] The above embodiments are only used to illustrate the design concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A highly efficient compound biochemical deodorant, characterized in that, It comprises the following components, by weight: 0.05-0.5% active ingredient of biosurfactant, 0.01-0.12% synthetic surfactant, 10-30% oxidant, 0.2-0.7% metal ion activator, 0.5-3.0% active ingredient of biochelating agent, 1-5% stabilizer, and 80-150% water; wherein the biosurfactant is one or more of rhamnolipids, surfactants, or saponins.

2. The high-efficiency compound biochemical deodorizer according to claim 1, characterized in that, The metal ion activator is a transition metal ion activator, and the biological chelating agent is a metabolite of Bacillus subtilis.

3. The high-efficiency compound biochemical deodorizer according to claim 1, characterized in that, The oxidant is selected from sodium percarbonate, hydrogen peroxide, and persulfate.

4. The high-efficiency compound biochemical deodorizer according to claim 1, characterized in that, The effective components of the biosurfactant are calculated using one of the following methods: rhamnolipids: total rhamnolipid content = rhamnosine content determined by catechol colorimetric method × 2.5; surfactants: quantified by HPLC or LC-MS; saponins: quantified by vanillin-sulfuric acid method or HPLC.

5. The high-efficiency compound biochemical deodorizer according to claim 1, characterized in that, The synthetic surfactant is a nonionic surfactant or anionic surfactant.

6. The application of the high-efficiency compound biochemical deodorizer according to claim 1 in the treatment of odor from livestock and poultry farming, characterized in that, The odor control for livestock and poultry farming includes deodorization of the environment inside the livestock and poultry houses and / or deodorization of manure and / or end-point odor reduction in livestock and poultry deodorization rooms.

7. The application according to claim 6, characterized in that, When the highly efficient compound biochemical deodorizer is diluted to the working solution, the effective concentration of the biosurfactant is: rhamnolipin 50-500 mg / L, or surfactant 20-200 mg / L, or saponin 0.1-2.0 g / L.

8. A method for preparing the high-efficiency compound biochemical deodorant according to claim 1, characterized in that, Includes the following steps: A stabilizer, a biosurfactant, a biochelating agent, a transition metal ion activator, and a nonionic or anionic surfactant are added sequentially to an aqueous solution of the oxidant and mixed thoroughly. The biochelating agent is obtained by inoculating Bacillus subtilis into a chelating agent culture medium, culturing, separating, and taking the supernatant.

9. The preparation method according to claim 8, characterized in that, The chelating agent culture medium is one with added Fe. 2+ and Cu 2+ The LB medium; the transition metal ion activator comprises 1 part by mass of a transition metal salt, 20 parts by mass of citric acid, and 50 parts by mass of sodium citrate, wherein the transition metal salt is selected from one of FeSO4, CuSO4, and MnSO4.

10. The preparation method according to claim 8, characterized in that, The stabilizer is one or more of polyols, polyethers, and polysaccharides, or a combination thereof.

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