Biological treatment and emission reduction storage method for kitchen waste and application of biological treatment and emission reduction storage method

Abstract

The invention discloses a kitchen waste biological treatment and emission reduction storage method and application thereof. By adding a compound lactic acid bacteria preparation, odor emission caused by rapid acidification and reproduction mildewing and corruption in the material storage process is achieved. Meanwhile, before the hermetia illucens is converted into the kitchen waste, zygosaccharomyces bayer with the acidophilic characteristic is added for secondary fermentation, organic acid (VFAs) and ammonia nitrogen in the material are converted into yeast protein, the inhibition effect of free organic acid on growth and reproduction of hermetia illucens larvae is reduced, inorganic ammonia nitrogen is converted into biological organic nitrogen (amino acid and the like), and the biological organic nitrogen is converted into biological organic nitrogen (amino acid and the like); organic carbon of the material is converted into soluble nutrients (SCOD) which are more easily absorbed by the hermetia illucens, so that the larvae of the hermetia illucens are promoted to quickly and efficiently convert the kitchen waste, and the volatilization of ammonia ions in the conversion process of the hermetia illucens is reduced. The related technology provided by the invention is beneficial to ammonia emission reduction and quality and efficiency improvement in the process of industrial breeding of hermetia illucens.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to a method for biological treatment, emission reduction and storage of kitchen waste and an application thereof. Technical Background

[0002] If nutritious food waste is handled properly, it can be called a resource product. Food waste is extremely easy to rot and deteriorate. During the accumulation process, a large amount of leachate will be generated, and it will also emit a foul odor, which will have a bad impact on the surrounding atmosphere and water environment, and indirectly affect human health.

[0003] At present, the treatment technologies for food waste are divided into biological and non-biological treatment technologies, including incineration, landfill, anaerobic digestion, aerobic composting and insect transformation. The use of black soldier fly larvae to transform food waste is gradually gaining popularity, and the use of black soldier flies to treat food waste has received widespread attention at home and abroad. Black soldier fly larvae can use their powerful digestive enzymes to effectively decompose the nutrients in food waste and convert them into nutrients for the insect body. The remaining residues are often applied to the soil as organic fertilizers, which is beneficial for stimulating the activity of microorganisms in the soil, improving the internal environment of the soil, and promoting the growth of crops. The biological transformation technology based on black soldier fly larvae can effectively treat food waste to synthesize insect protein and oil for feeding, which is an important way to solve the problems of waste treatment and feed protein shortage.

[0004] However, the prior art kitchen waste will produce a large amount of odor substances during the storage process and after the black soldier fly transformation after collection and transportation, mainly ammonia. This is mainly because a large number of microorganisms breed and reproduce in the kitchen waste, decomposing the nitrogen-containing organic matter in the material and releasing odor components such as ammonia and hydrogen sulfide. At the same time, the transformation of kitchen waste by black soldier flies will cause a large amount of inorganic ammonia nitrogen in the material to volatilize. Therefore, the emission of odors such as ammonia generated during the storage of kitchen waste and the transformation of black soldier flies is a technical problem to be solved. Summary of the invention

[0005] The invention provides a method for biological pretreatment and deodorization of kitchen waste storage process and biological enhancement of black soldier fly transformation, which is composed of the following steps: first, a composite lactic acid bacteria preparation (Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc lactis, Lactobacillus paracasei, Lactobacillus rhamnosus) is evenly mixed with kitchen waste and then stored, and multiple lactic acid bacteria are used to synergistically complete the rapid decomposition and acidification of kitchen waste through multiple degradation enzymes, thereby avoiding the reproduction of miscellaneous bacteria and achieving stable storage. Secondly, before the kitchen waste is used as a raw material for the transformation of black soldier flies, a Bayer zygosaccharomyces cerevisiae with acidophilic characteristics is added to further degrade macromolecular nutrients, transform volatile ammonium ions into organic nitrogen, improve the pH of the material, enhance the adaptability and palatability of black soldier fly larvae to kitchen waste, and contribute to the reduction of ammonia emissions and quality improvement and efficiency enhancement in the process of factory breeding of black soldier flies.

[0006] Specifically, the present invention provides a method for reducing and storing kitchen waste by biological treatment, which comprises the following steps:

[0007] Step 1: adding a composite lactic acid bacteria agent to the kitchen waste and fermenting at room temperature for 5 to 7 days, wherein the composite lactic acid bacteria agent consists of Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc lactis, Lactobacillus paracasei, and Lactobacillus rhamnosus;

[0008] Step 2: adding Zygosaccharomycesbailii to the food waste obtained after the treatment in step 1 and fermenting at room temperature for 1 to 3 days;

[0009] Step 3: Add black soldier fly larvae to the food waste obtained after the treatment in step 2, and culture them at room temperature until the average weight of the insect body no longer increases.

[0010] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste of the present invention: in step 1, the concentration of the composite lactic acid bacteria agent is 1.0×10 9 CFU / mL, the amount of the composite lactic acid bacteria agent added to the kitchen waste is 1-3wt%o.

[0011] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste of the present invention: in step 1, the composite lactic acid bacteria agent is Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc lactis, Lactobacillus paracasei and Lactobacillus rhamnosus inoculated into the culture medium at a colony count ratio of 1:1:1:1:1, and cultured at 20-30°C until the total bacterial concentration reaches 1.0×10 9 CFU / mL.

[0012] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste of the present invention: in step 2, the concentration of the Zygosaccharomyces bailii inoculant is 1 to 3.0×10 8The amount of Zygosaccharomyces bailii added to the food waste is 0.5-2wt%.

[0013] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste described in the present invention: in step 2, the Bayer's yeast (Zygosaccharomyces bailii) inoculant is inoculated into the culture medium for activation culture for 48 to 96 hours, and the culture temperature is 20 to 30°C.

[0014] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste of the present invention: in step 3, the moisture content of the kitchen waste obtained after treatment in step 2 is adjusted to 75-80% and then black soldier fly larvae are added.

[0015] As a preferred embodiment of the method for biological treatment, emission reduction and storage of kitchen waste of the present invention: in step 3, the amount of black soldier fly larvae added is 1000 black soldier fly larvae per 1 kg of kitchen waste.

[0016] Beneficial effects of the present invention: The present invention provides a technology for reducing odor emissions during the storage of food waste and a technology for bio-enhancing the subsequent black soldier fly conversion process. Rapid acidification of the material during storage is achieved by adding a composite lactic acid bacteria preparation, and odor emissions caused by mildew and corruption are reduced. At the same time, before the black soldier flies convert the food waste, Bayer's yeast with acidophilic characteristics is added for secondary fermentation to convert organic acids (VFAs) and ammonia nitrogen in the material into yeast body proteins, thereby reducing the inhibitory effect of free organic acids on the growth and reproduction of black soldier fly larvae. At the same time, inorganic ammonia nitrogen is converted into biological organic nitrogen (amino acids, etc.), and the organic carbon of the material is converted into soluble nutrients (SCOD) that are easier for black soldier flies to absorb, thereby promoting the black soldier fly larvae to quickly and efficiently convert food waste and reduce the volatilization of ammonia ions during the black soldier fly conversion process. The relevant technology of the present invention is helpful for reducing ammonia emissions and improving quality and efficiency in the process of factory-farming black soldier flies. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0018] Embodiment 1:

[0019] 5kg of freshly collected kitchen waste was mixed with rice husk powder to adjust the moisture content to 75%, and placed in a blue turnover box. According to the ratio of 1.0kg of kitchen waste to 1000 black soldier fly seedlings, the insect seedlings were spread on the surface of the kitchen waste material, and the breeding box was placed in an environment at room temperature of 30℃ for black soldier fly transformation. When the average weight of the insect body no longer increases, the transformation is considered to be completed.

[0020] Without adding fast-acidifying composite lactic acid bacteria preparations, food waste can only rely on the lactic acid bacteria in its own materials to ferment and produce acid, which has a slow effect. The pH value of the material is higher than 4, and the VFAs concentration is only 3872 mg / L. After transformation by black soldier flies, the average weight of the larvae was 204 mg, the survival rate was 88%, and the total nitrogen loss rate was as high as 19.58%, indicating that a large amount of nitrogen was released into the environment in the form of ammonia.

[0021] Embodiment 2:

[0022] (1) MRS medium was used to activate Lactobacillus plantarum ACCC11095, Lactobacillus pentosus ATCC 8041, Leuconostoclactis ATCC 19256, Lactobacillus paracasei ATCC 334, and Lactobacillus rhamnosus ATCC 7469. Each strain was inoculated into the MRS medium at 1.0% (v / v) according to an equal colony ratio (colony number ratio of 1:1:1:1:1), and mixed culture was carried out at 30°C and 200 rpm. When the total bacterial concentration reached 1.0×10 9 CFU / mL was used as a microbial acidification agent. According to the addition ratio of 3.0‰ (W / W), the composite lactic acid bacteria agent was added to the food waste and fermented at room temperature for 5 days for rapid biological acidification pretreatment. After 5 days of room temperature fermentation, the material state was basically stable. The addition of microbial acidification agents can significantly reduce the pH of the food waste raw materials, produce a large amount of volatile organic acids (VFAs), and quickly achieve material acidification, which ultimately prevents the increase of material SCOD caused by microbial fermentation during the storage stage, and significantly reduces ammonium nitrogen and nitrate nitrogen.

[0023] (2) 5 kg of the acidified kitchen waste obtained in step (1) was mixed evenly with rice husk powder to adjust the moisture content to 75%, and placed in a blue turnover box breeding box. According to the ratio of 1.0 kg of kitchen waste to 1000 black soldier fly seedlings, the insect seedlings were spread on the surface of the kitchen waste material, and the breeding box was placed in an environment at room temperature of 30°C for black soldier fly transformation. When the average weight of the insect body no longer increases, the transformation is considered to be completed.

[0024] After acidifying the kitchen waste with a high ratio of 3.0‰ (W / W) compound lactic acid bacteria, the pH of the material further dropped to 3.52, and the VFAs concentration further increased, indicating that the high-concentration compound lactic acid bacteria preparation can accelerate the acidification of the material. The concentrations of SCOD, ammonium nitrogen and nitrate nitrogen continued to decrease, indicating that the reproduction of bacteria and microorganisms in the material was inhibited. After the black soldier fly transformation, the average weight of its larvae was only 178 mg, the survival rate was greatly affected, only 78%, the insect protein content was 40.39%, and the total nitrogen loss rate was 11.35%, indicating that the nitrogen released into the environment in the form of ammonia was reduced.

[0025] Embodiment 3:

[0026] (1) Lactobacillus plantarum ACCC11095, Lactobacillus pentosus ATCC 8041, Leuconostoclactis ATCC 19256, Lactobacillus paracasei ATCC 334, and Lactobacillus rhamnosus ATCC 7469 were activated using MRS medium. Each strain was inoculated into the MRS medium at 1.0% (v / v) according to the same colony ratio, and mixed culture was carried out at 30°C and 200 rpm. When the total bacterial concentration reached 1.0×10 9 CFU / mL was used as a lactic acid bacteria acidifying agent. According to the addition ratio of 3.0‰ (W / W), the mixed lactic acid bacteria acidifying agent was added to the food waste and fermented at room temperature for 5 days for rapid biological acidification pretreatment.

[0027] The state of the material is basically stable after fermentation. The addition of composite lactic acid bacteria preparations can significantly reduce the pH of the food waste raw materials, produce a large amount of volatile organic acids (VFAs), and quickly achieve material acidification, ultimately preventing the increase of material SCOD due to microbial fermentation during the storage stage, and significantly reducing both ammonium nitrogen and nitrate nitrogen.

[0028] (2) Saccharomyces cerevisiae ATCC 26603 was inoculated into YPD liquid medium for activation culture for 72 hours at a temperature of 30°C and a rotation speed of 150 rpm. When the cell concentration reached 3.0×10 8 CFU / mL is used as a bacterial agent;

[0029] 1.0‰ (W / W) of Saccharomyces cerevisiae ATCC 26603 inoculant was added to the food waste after microbial acidification obtained in step (1), and fermented at room temperature of 30°C for 48 hours. During the fermentation process, the food waste material was stirred evenly.

[0030] (3) 5 kg of the food waste obtained after the treatment in step (2) was mixed with rice husk powder to adjust the moisture content to 75%, and placed in a blue turnover box breeding box. According to the ratio of adding 1000 black soldier fly seedlings to 1.0 kg of food waste, the insect seedlings were spread on the surface of the food waste material, and the breeding box was placed in an environment at room temperature of 30°C for black soldier fly transformation. When the average weight of the insect body no longer increases, the transformation is considered to be completed.

[0031] The food waste treated by acidification pretreatment and brewer's yeast pre-fermentation was used as feed to breed black soldier fly larvae. After fermentation by brewer's yeast, the pH of the material was 3.55 and did not increase significantly. At the same time, the concentration of VFAs increased further, indicating that brewer's yeast produced organic acids under anaerobic conditions. The SCOD increased to 8914 mg / L, and the survival rate of the larvae after black soldier fly transformation was 82%. The protein content of the insect body was 41.26%, the conversion cycle was shortened to 8 days, and the total nitrogen loss rate was reduced from 19.58% to 12.98%.

[0032] Embodiment 4:

[0033] (1) MRS medium was used to activate Lactobacillus plantarum ACCC11095, Lactobacillus pentosus ATCC 8041, Leuconostoclactis ATCC 19256, Lactobacillus paracasei ATCC 334, and Lactobacillus rhamnosus ATCC 7469. Each strain was inoculated into the MRS medium at 1.0% (v / v) according to an equal colony ratio (colony number ratio of 1:1:1:1:1), and mixed culture was carried out at 30°C and 200 rpm. When the total bacterial concentration reached 1.0×109 CFU / mL was used as a microbial acidification agent. According to the addition ratio of 3.0‰ (W / W), the compound lactic acid bacteria agent was added to the food waste and fermented at room temperature for 5 days for rapid biological acidification pretreatment. After 5 days of room temperature fermentation, the material state was basically stable. The addition of the compound lactic acid bacteria preparation can significantly reduce the pH of the food waste raw materials, produce a large amount of volatile organic acids (VFAs), and quickly achieve material acidification, which ultimately prevents the increase of material SCOD due to microbial fermentation during the storage stage, and significantly reduces ammonium nitrogen and nitrate nitrogen.

[0034] (2) The acidophilic and salt-tolerant Zygosaccharomyces bailii CICC 32190 was inoculated into YPD liquid medium for activation culture for 72 hours at a temperature of 30 degrees Celsius and a rotation speed of 150 rpm. When the cell concentration reached 3.0×10 8 CFU / mL is used as a bacterial agent.

[0035] 1.0‰ (W / W) of acidophilic and salt-tolerant Zygosaccharomyces bailii CICC 32190 was added to the food waste after microbial acidification obtained in step (1), and fermented at room temperature of 30°C for 48 hours. During the fermentation process, the materials were stirred evenly.

[0036] (3) 5 kg of the food waste obtained after the treatment in step (2) was mixed with rice husk powder to adjust the moisture content to 75%, and placed in a blue turnover box breeding box. According to the ratio of adding 1000 black soldier fly seedlings to 1.0 kg of food waste, the insect seedlings were spread on the surface of the food waste material, and the breeding box was placed in an environment at room temperature of 30°C for black soldier fly transformation. When the average weight of the insect body no longer increases, the transformation is considered to be completed.

[0037] The kitchen waste treated with acidification pretreatment and Bayer yeast pre-fermentation was used as feed for breeding black soldier fly larvae. Yeast fermentation increased the pH of the material to 4.46, and the SCOD was increased to 15530 mg / L, which effectively alleviated the inhibitory effect of the acidic environment on the growth of black soldier fly larvae, and the larval survival rate was significantly increased from 80% to 96%. The protein content of the insect body increased from 39.22% to 46.27%, the conversion cycle was shortened to 5 days, and the total nitrogen loss was reduced from 19.58% to 8.78%, indicating that the inorganic ammonium nitrogen was absorbed by yeast and converted into organic nitrogen, which can effectively reduce the proportion of nitrogen released in the material as ammonia.

[0038] Table 1 Physical and chemical properties of solid residue from kitchen waste

[0039]

[0040] Table 2 Effect of biological pretreatment on the transformation of food waste solid residue by black soldier flies

[0041]

Claims

1. A method for biological treatment, emission reduction and storage of kitchen waste, characterized by: The following steps are included: Step 1: adding a composite lactic acid bacteria agent to the kitchen waste and fermenting at room temperature for 5 to 7 days, wherein the composite lactic acid bacteria agent consists of Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc lactis, Lactobacillus paracasei, and Lactobacillus rhamnosus; Step 2: adding Zygosaccharomycesbailii to the food waste obtained after the treatment in step 1 and fermenting at room temperature for 1 to 3 days; Step 3: Add black soldier fly larvae to the food waste obtained after the treatment in step 2, and culture them at room temperature until the average weight of the insect body no longer increases.

2. The method for reducing and storing kitchen waste by biological treatment according to claim 1, characterized in that: In step 1, the concentration of the compound lactic acid bacteria agent is 1.0×10 9 CFU / mL, the amount of composite lactic acid bacteria agent added to food waste is 1.0~3.0wt‰.

3. The method for reducing and storing kitchen waste by biological treatment according to claim 2, characterized in that: In step 1, the composite lactic acid bacteria agent is to inoculate Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc lactis, Lactobacillus paracasei, and Lactobacillus rhamnosus into a culture medium at a colony count ratio of 1:1:1:1:1, and culture at 20-30°C until the total bacterial concentration reaches 1.0×10 9 CFU / mL.

4. The method for reducing the discharge and storing food waste by biological treatment according to any one of claims 1 to 3, characterized in that: In step 2, the concentration of the Zygosaccharomyces bailii inoculant is 1 to 3.0×10 8 The amount of Zygosaccharomyces bailii added to the food waste is 0.5 to 2.0 wt‰.

5. The method for reducing and storing kitchen waste by biological treatment according to claim 4, characterized in that: In step 2, the Zygosaccharomyces bailii inoculum is prepared by inoculating Zygosaccharomyces bailii into a culture medium for activation culture for 48 to 96 hours at a culture temperature of 20 to 30°C.

6. The method for biological treatment, emission reduction and storage of kitchen waste according to any one of claims 1 to 3, characterized in that: In step 3, the food waste obtained after the treatment in step 2 is adjusted to have a moisture content of 65-80% and then black soldier fly larvae are added.

7. The method for reducing and storing kitchen waste by biological treatment according to claim 6, characterized in that: In step 3, the amount of black soldier fly larvae added is 1000 black soldier fly larvae per 1 kg of food waste.

8. Application of the method for biological treatment, emission reduction and storage of kitchen waste according to claim 1 in black soldier fly breeding and kitchen waste deodorization.

9. Application of the method for biological treatment, emission reduction and storage of kitchen waste according to claim 1 in reducing ammonia emissions from kitchen waste.

Images