Methods for the resource utilization of kitchen waste concentrate

Abstract

This application relates to the field of waste treatment technology, and in particular to a method for the resource utilization of concentrated kitchen waste liquid. The method includes the following steps: after three-phase separation treatment of kitchen waste, the liquid phase is collected; the liquid phase is then subjected to a first fermentation treatment and distillation treatment sequentially to obtain a concentrated liquid; the concentrated liquid is used to feed saprophytic insect larvae. This application's method for resource utilization proposes a new approach to the use of concentrated liquid, feeding saprophytic insect larvae. On the one hand, this utilization method can efficiently and harmlessly treat the concentrated liquid, eliminating the need for waste and reducing the environmental burden of kitchen waste; on the other hand, during the feeding process, the excrement of the insect larvae can serve as high-quality organic fertilizer; furthermore, the adult insects that grow from this larvae are rich in protein and fat, and can serve as high-quality animal feed or feed ingredients, possessing extremely high economic value. Therefore, the method of this application has extremely high environmental and economic value.

Description

Technical Field

[0001] This application relates to the field of waste treatment technology, and in particular to a method for the resource utilization of concentrated kitchen waste liquid. Background Technology

[0002] The most common method for centralized processing of food waste is to separate it into solid, liquid, and oil phases after sorting and crushing. The oil is then recycled for processing into biodiesel, which is one of the main sources of revenue for food waste treatment projects. The liquid and solid phases are also rich in organic matter and can be utilized as resources.

[0003] Solid residue (referred to as solid residue) contains insoluble organic matter, such as proteins and polysaccharides. It can be sent to an anaerobic digestion system to produce methane, or it can be made into protein feed as a fishmeal substitute, or it can be used to feed insects.

[0004] The liquid phase (also known as three-phase centrifuge liquid) is rich in dissolved organic matter. Directional fermentation can produce small-molecule organic compounds such as acetic acid, ethanol, propionic acid, and propanol. After fermentation, distillation evaporates these small-molecule organic compounds, which are then condensed to produce a liquid carbon source. This liquid carbon source, rich in small-molecule organic matter, can be used as an external carbon source in wastewater treatment plants or in other fields. However, the remaining liquid at the bottom of the distillation vessel (referred to as concentrate) contains a large amount of oil, suspended particulate matter, and significant amounts of organic nitrogen, nitrogenous ammonia, phosphates, sodium ions, and chloride ions. It is considered waste and easily causes secondary pollution. These complex components make treatment difficult and costly, lacking effective utilization methods. It can only be disposed of after complex and expensive harmless treatment processes, resulting in high costs and no economic value. Summary of the Invention

[0005] The purpose of this application is to provide a method for the resource utilization of concentrated liquid obtained from kitchen waste. It aims to solve the technical problem in existing technologies where the concentrated liquid remaining after fermentation and distillation of three-phase centrifuged kitchen waste cannot be effectively utilized.

[0006] To achieve the above application objectives, the technical solutions adopted in this application are as follows:

[0007] In a first aspect, this application provides a method for the resource utilization of concentrated liquid obtained from kitchen waste, comprising the following steps:

[0008] After the kitchen waste undergoes three-phase separation, the liquid phase is collected.

[0009] The liquid phase was subjected to a first fermentation treatment and a distillation treatment in sequence to obtain a concentrated liquid;

[0010] The concentrate was used to feed saprophytic insect larvae.

[0011] This application proposes a novel approach to the resource utilization of concentrated liquid. The concentrated liquid is used to feed saprophytic insect larvae. The oils, organic matter, and salts in the concentrated liquid serve as nutrients for the larvae's growth. Furthermore, these saprophytic larvae can efficiently convert the organic waste in the concentrated liquid into their own proteins, fats, and other nutrients, eventually growing into adult insects. On one hand, this utilization method efficiently and harmlessly treats the concentrated liquid, eliminating waste and reducing the environmental burden of kitchen waste. On the other hand, the larvae's excrement during the feeding process can serve as high-quality organic fertilizer. Moreover, the resulting adult insects, rich in protein and fat, can be used as high-quality animal feed or fertilizer, thus yielding high-value-added products with significant economic value. Therefore, the method described in this application possesses extremely high environmental and economic value. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a sample of the concentrated solution obtained in step S2 of Example 1 of this application;

[0014] Figure 2 This is a schematic diagram of black soldier fly larvae hatching in step S3 of Embodiment 1 of this application;

[0015] Figure 3 This is a schematic diagram of obtaining a solid phase by three-phase centrifugation in Embodiment 6 of this application;

[0016] Figure 4 This is a schematic diagram of feeding black soldier flies to obtain adult insects in Example 6 of this application. Detailed Implementation

[0017] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0019] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items.

[0020] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0021] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass in the embodiments of this application can be a well-known unit of mass in the chemical industry, such as μg, mg, g, or kg.

[0022] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0023] Definition of terms: Kitchen waste: In this application, kitchen waste refers to garbage and kitchen scraps generated in daily life and food processing, catering services, and unit catering activities, including discarded vegetable leaves, leftover food, leftover rice, fruit peels, eggshells, tea dregs, bones (chicken bones, fish bones, etc.), etc. Its main sources are family kitchens, restaurants, hotels, canteens, markets and other industries related to food processing.

[0024] Three-phase centrifugal liquid (liquid phase): After three-phase separation treatment of kitchen waste, a solid phase, an oil phase, and a liquid phase are obtained. Here, "liquid phase" is a commonly used term in the industry, and it is a parallel term with "oil phase," but does not include the oil phase. However, it is a consensus in the industry that the liquid phase after three-phase separation treatment of kitchen waste inevitably still contains organic matter, rather than being an inorganic solution mixture. Therefore, "liquid phase" and "oil phase" are industry-specific terms, not distinctions made from a chemical perspective.

[0025] The first aspect of this application provides a method for the resource utilization of concentrated kitchen waste liquid, comprising the following steps:

[0026] S10: After the kitchen waste is processed by three-phase separation, the liquid phase is collected;

[0027] S20: The liquid phase is subjected to a first fermentation treatment and a distillation treatment in sequence to obtain a concentrated liquid;

[0028] S30: Use the concentrate to feed saprophytic insect larvae.

[0029] This application proposes a novel approach to utilizing concentrated liquid by feeding saprophytic insect larvae. The concentrated liquid, rich in oils and other organic matter, as well as salts, provides essential nutrients for the larvae's growth. Furthermore, these saprophytic larvae efficiently convert the organic waste in the concentrated liquid into their own protein, fat, and other nutrients, eventually maturing into adults. On one hand, this method efficiently and harmlessly treats the concentrated liquid, eliminating waste and reducing the environmental burden of kitchen waste. On the other hand, the larvae's excrement (insect droppings / sand) during feeding serves as high-quality organic fertilizer. Moreover, the resulting adult insects, rich in protein and fat, can be used as high-quality animal feed or feed additives, resulting in high-value-added products with significant economic value. Therefore, the method described in this application possesses both high environmental and economic value.

[0030] Step S10 is the three-phase centrifugation step. In the example, kitchen waste can be sorted, crushed, heated and then transferred to a three-phase centrifuge for centrifugation to separate the oil phase, liquid phase and solid phase, and collect the liquid phase.

[0031] Step S20 is the liquid phase treatment step. The liquid phase (three-phase centrifuged liquid) is rich in dissolved organic matter. The first fermentation treatment can be anaerobic fermentation, using endogenous microorganisms from the substrate, at a mesophilic temperature of 30-40°C, for approximately 4-5 days. Alternatively, it can be ethanol-directed fermentation, etc. The first fermentation treatment produces small-molecule organic compounds such as acetic acid, ethanol, propionic acid, and propanol. After the first fermentation treatment, distillation is performed, evaporating these small-molecule organic compounds. The resulting liquid is then condensed to produce a liquid carbon source. This liquid carbon source is rich in small-molecule organic compounds and can be used as an external carbon source in wastewater treatment plants or in other applications. The remaining liquid at the bottom of the still after distillation is the concentrate.

[0032] Step S30 is the step of using the concentrate to feed insect larvae.

[0033] The concentrated solution obtained through steps S10 and S20 has a water content of 70%–80%, such as Figure 1As shown, it is generally brown or dark brown in appearance, rich in oils and other organic matter as well as salts. Its composition is complex and cannot be effectively utilized by existing technologies. Its odor is similar to butyric acid or valeric acid, and its texture is similar to vegetable oil. It is not easily perishable and should be stored in a sealed container at room temperature.

[0034] In some embodiments, the insect larvae include at least one of black soldier fly larvae, fly maggots, mealworms, and cockroaches, with black soldier fly larvae being the preferred choice. These insect larvae are all saprophytic insect larvae, which can use the concentrated liquid as feed and convert it into their own nutrients, resulting in high conversion rates and high yields.

[0035] In some embodiments, the concentrate is used for feeding in the following manner (1), including the following steps:

[0036] S31: Provides solid support material for attaching insect larvae to the support material, and adds concentrated liquid to the support material to feed the insect larvae.

[0037] Method (1) involves directly feeding the insects with a concentrated liquid, requiring the addition of solid support material for the larvae to attach. In some embodiments, the support material may include at least one of agricultural by-products, sawdust, mushroom waste, plastic granules, and rubber granules; wherein, agricultural by-products may include at least one of corn stalks, rapeseed stalks, soybean stalks, wheat stalks, peanut stalks, rice stalks, corn cobs, peanut shells, and rice husk powder. These support materials are mainly waste materials, which can be reused, and are inexpensive and readily available. The support material can be crushed first to a particle size of less than 20 mesh, which helps the larvae attach and be fed, and facilitates the subsequent separation of the insect body from the residue.

[0038] When adding the concentrated feed, it's best to add it in small, frequent amounts, adding it only when the insect larvae are almost finished with the feed, rather than adding it all at once or in two separate additions. This is because the concentrated feed is a liquid, and adding it all at once or in two small additions would make the feeding environment too watery, potentially drowning the insects and preventing their survival. Furthermore, adding too much feed in a short time would cause the larvae to overeat and decompose the concentrated feed, keeping it fresh and allowing the larvae to continuously ingest fresh feed and consume it evenly, resulting in more stable growth. A good guideline is 1 ton of concentrated feed to 1.5 kg of insect eggs, which can produce 200-300 kg of larvae per ton of concentrated feed.

[0039] In this method, agricultural by-products or sawdust are used as support material, and the feeding period is 8–15 days. After 8 days of feeding, the insect body length can reach 10–15 mm. The weight ratio of concentrated liquid to adult insects produced from larvae (feed / insect ratio) is 1:(0.10–0.18). In the example, it can be any value or a range between any two of 1:0.10, 1:0.12, 1:0.14, 1:0.16, and 1:0.18. In the example, after 8 days of feeding, the concentrated liquid is added to extend the feeding period. The larvae will continue to grow and pupate, and a small number of pupae can emerge as adults.

[0040] In the demonstration, when mushroom waste was used as the support material, the insects began to die from the third day onwards. When plastic granules were used, the insects survived but grew slowly; by the eighth day, most insects were 7mm long, with a very few reaching 12mm; by the fifteenth day, most insects were 10mm long. When rubber granules were used as the support material, the insects either escaped or died. This was mainly due to the lack of essential nutrients and the presence of toxic substances in these support materials.

[0041] Therefore, the supporting material can be the aforementioned agricultural waste or sawdust. By the 8th day of feeding, the insects and residues are easily separated due to the small particle size and relative dryness of the supporting material. If more material is added or the feeding time is extended, the insects and residues may become difficult to separate.

[0042] In some embodiments, the concentrate is used for feeding in the following manner (2), including the following steps:

[0043] S32: The concentrate is subjected to a second fermentation treatment, and the fermentation product is used to feed insect larvae;

[0044] This (2) method involves a second fermentation of the concentrate, which helps to convert the organic matter in the concentrate into a form that is more easily digested and absorbed by insect larvae, thus promoting their feeding and growth. This second fermentation can be aerobic or anaerobic, with lactic acid fermentation being a preferred option. Lactic acid fermentation has the advantage of a simple process, and more importantly, it can hydrolyze recalcitrant organic matter such as cellulose in the concentrate into smaller molecular weight components such as lactic acid, amino acids, hemicellulose, and sugars, which are beneficial for insect larvae feeding and growth. The temperature of the second fermentation can be 30–45℃, and the fermentation time can be 24–48 hours.

[0045] Furthermore, during the second fermentation process, grain by-products such as rice bran and wheat bran can be added. These by-products provide additional organic matter and nutrients, making the product of the second fermentation process more conducive to the feeding and growth of insect larvae. Therefore, the raw materials for the second fermentation process can include concentrated liquid, grain by-products, and lactic acid bacteria, with a mass ratio of (3-10):(2-10):1. In the example, the ratio may include, but is not limited to, any ratio or a range between any two of (3, 4, 5, 7, or 10):(2, 3, 5, 7, or 10):1.

[0046] In this (2) method, the feeding time for insect larvae can be 5 to 7 days; through this (2) method, the weight ratio of the fermentation product used to the adult insect produced by the insect larvae is 1:(0.2 to 0.3). In the example, it can be any ratio or any two ratios of 1:0.2, 1:0.25, 1:0.28, 1:0.3. It can be seen that this method of feeding insect larvae also has a high yield.

[0047] In some embodiments, the concentrate is used for feeding in the following manner (3), including the following steps:

[0048] S33: Collect the solid phase after the three-phase centrifugation treatment, mix the concentrate with the solid phase, and use the resulting mixture to feed insect larvae.

[0049] The conventional treatment of the solid phase obtained after three-phase centrifugation of kitchen waste is anaerobic treatment to produce methanogens or to make protein feed, which requires additional equipment and space. Some studies have also used the solid phase to feed insect larvae. According to research, this (3) method uses the solid phase after three-phase centrifugation of kitchen waste in conjunction with the above-mentioned concentrate to feed insect larvae, so that the solid phase can also be utilized without additional equipment and space, and the co-feeding is beneficial to the growth of insect larvae and increases the yield. In the example, the water content of the solid phase is about 75% to 80%, the appearance is grayish-brown, it emits the smell of rotten food, the texture is similar to minced meat, and it is extremely easy to spoil. The solid phase can be the solid phase obtained from the discharge port of the three-phase separator on the same day, or the solid phase stored in the refrigerator for no more than 1 day.

[0050] In the above method (3), the mass ratio of solid phase to concentrated liquid is (1-4):1. In the example, it can be any value or a range between any two values, including but not limited to 1:1, 2:1, 3:1, and 4:1. The solid-liquid ratio in these mixtures is reasonable and more conducive to the feeding, absorption, and growth of insect larvae. The feeding time can be 5-8 days. If the feed is added or the feeding time is extended, it may be difficult to separate the insect body from the residue. According to the above feeding method, the weight ratio of the mixture of solid phase and concentrated liquid to the adult insects produced by the insect larvae (feed / insect ratio) can reach 1:(0.24-0.32), which has a very significant output ratio.

[0051] In the demonstration example, taking the feeding of black soldier fly larvae as an example, feed can be added multiple times during the feeding process. When the solid phase to concentrated liquid mass ratio is 4:1, the final feed / larvae ratio is 1:(0.24-0.28), and the average larval length is 20 mm. When the solid phase to concentrated liquid mass ratio is 3:1, the final feed / larvae ratio is 1:(0.26-0.28), and the average larval length is 20 mm. When the solid phase to concentrated liquid mass ratio is 2:1, the final feed / larvae ratio is 1:(0.3-0.32), and the average larval length is 20 mm. When the solid phase to concentrated liquid mass ratio is 1:1, the larvae will escape from the rearing tray due to the excessively diluted feed.

[0052] In this (3) method, the solid phase and the concentrate are mixed and then fed to the insect larvae. Whether compared to feeding directly with the solid phase or feeding directly with the concentrate in (1) method, this (3) method is conducive to further reducing the feed / insect ratio, indicating that the concentrate and the solid phase can complement each other's nutrients. Furthermore, the mixing of the concentrate and the solid phase makes the solid residue softer, making it easier for the insect larvae to burrow in.

[0053] Steps S31, S32, and S33 above are parallel and can be implemented using any of the three methods. When feeding insect larvae, they can be fed in breeding trays, with feeding done in two or more additions, the amount of feed being such that the larvae consume most of it before the next addition. The breeding density is 5.5-6g larvae / square meter. After raising the larvae to adulthood, the insect residue and adult larvae are separated and harvested. Both the insect residue and adult larvae are high-value products that can be sold to generate economic value. Simultaneously, the concentrated liquid is utilized rationally, reducing environmental pressure and eliminating the need for additional investment in site and equipment for complex harmless treatment.

[0054] The following description is based on specific embodiments.

[0055] Example 1

[0056] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste, including the following steps:

[0057] S1: After the kitchen waste is processed through three-phase separation, the liquid phase is collected;

[0058] S2: After the liquid phase is subjected to fermentation and distillation treatments in sequence, the following is obtained: Figure 1 The concentrated liquid shown is an anaerobic fermentation, the microorganisms used as substrates are endogenous microorganisms, the fermentation temperature is 30℃, the fermentation residence time is about 4 days, and the fermentation mode is sequencing batch fermentation.

[0059] S3: Hatch the black soldier fly eggs under warm, well-ventilated conditions. After hatching, feed them a mixture of coarse wheat bran and chick feed as brooder food. The weight ratio of eggs, wheat bran, chick feed, and water is 1:10:10:40. After preparing the brooder food, evenly scatter the hatched black soldier fly larvae on the surface of the food and place it in a cool, well-ventilated, and dark place. After 4-5 days, the larvae will grow to 4mm, and you will obtain black soldier fly larvae. Figure 2 As shown;

[0060] S4: Using the method described in (1) above, provide solid support material, attach black soldier fly larvae to the support material, and add concentrated liquid to the support material to feed the black soldier fly larvae; the support material is a mixture of nine kinds of agricultural by-products, including corn stalks, rapeseed stalks, soybean stalks, wheat stalks, peanut stalks, rice stalks, corn cobs, peanut shells, and rice husk powder, crushed to 20 mesh, as well as sawdust. When feeding, add concentrated liquid in small amounts and multiple times, 3 to 4 times a day, with the weight increasing daily according to the growth of the insects, but not exceeding 5% of the total input material per unit breeding area. Feed for 15 days, with a breeding density of 5.5g-6g larvae / square meter.

[0061] Example 2

[0062] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 1 is that the support material in step S4 is replaced with mushroom waste, and everything else is the same.

[0063] Example 3

[0064] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 1 is that the support material in step S4 is replaced with plastic granules, and everything else is the same.

[0065] Example 4

[0066] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 1 is that the support material in step S4 is replaced with rubber particles, and everything else is the same.

[0067] Example 5

[0068] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 1 is that step S4 is changed to the method described in (2) above. The concentrated liquid, agricultural by-products such as rice bran and wheat bran, and lactic acid bacteria are fermented in a mass ratio of 5:5:1. The fermentation temperature is 35°C, the fermentation environment is anaerobic, the fermentation residence time is 3 days, and the fermentation mode is sequencing batch fermentation. The fermentation product is used to feed black soldier fly larvae. The feeding amount, feeding frequency, and other parameters are the same as in Embodiment 1.

[0069] Example 6

[0070] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 1 is that step S4 is changed to the above-mentioned (3) method, and the solid phase obtained from the three-phase centrifugation in step S1 is also collected first, such as... Figure 3 As shown. Step S4 is modified by mixing the solid phase and concentrated liquid at a mass ratio of 4:1 to obtain a mixture. This mixture is added to the breeding tray. After the first feeding, black soldier fly larvae are scattered on the surface without being stirred. The larvae are fed a second time after they have mostly consumed the feed; they will then stir and level the feed themselves. The feeding amount, feeding frequency, and other parameters are the same as in Example 1. The resulting adult larvae are as shown. Figure 4 As shown.

[0071] Example 7

[0072] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 6 is that the mass ratio of solid phase to concentrated liquid is changed from 4:1 to 3:1, and all other aspects are the same.

[0073] Example 8

[0074] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 6 is that the mass ratio of solid phase to concentrated liquid is changed from 4:1 to 2:1, and all other aspects are the same.

[0075] Example 9

[0076] This embodiment provides a method for the resource utilization of concentrated liquid obtained from kitchen waste. The only difference from Embodiment 6 is that the mass ratio of solid phase to concentrated liquid is changed from 4:1 to 1:1, and all other aspects are the same.

[0077] Comparative Example 1

[0078] In this comparative example, the solid phase after three-phase centrifugation in step S1 of Example 1 was collected and used directly to feed black soldier fly larvae, with feeding done twice, on day 1 and day 4.

[0079] Comparative Example 2

[0080] The only difference between this comparative example and Comparative Example 1 is that the addition of materials has been changed from two additions to multiple additions.

[0081] Comparative Example 3

[0082] The only difference between this comparative example and Example 1 is that the fermentation and distillation steps in step S2 are omitted, and the liquid phase from step S1 is directly used as feed to feed the black soldier fly larvae in step S4. The feeding amount, feeding frequency, and other parameters are also the same as in Example 1.

[0083] The differences between Examples 1 to 9 and Comparative Examples 1 to 3 are shown in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] Comparative Examples 1 and 2 show that, compared to the excessively long interval between feedings in Comparative Example 1, which led to solid phase decay, black soldier flies preferred the fresh food in Comparative Example 2. The multiple feedings in Comparative Example 2, compared to only two feedings in Comparative Example 1, reduced the feed / fly ratio and increased yield. This indicates that reducing the degree and proportion of solid phase decay, as well as decreasing the thickness of the feed, facilitated black soldier fly respiration, thereby increasing their feeding rate.

[0088] In Comparative Example 3, feeding directly with three-phase centrifuged liquid resulted in a large number of larvae suffocating and dying due to excessively high water content (≥95%). This required the addition of a large amount of supplementary feed, which had low nutritional value, low larval production rate, and the inability to classify and utilize the effective components in the centrifuged liquid, easily leading to resource waste.

[0089] Compared to the existing technology of using only solid phase to feed black soldier flies in Comparative Example 1, Examples 6 to 9 use the above-mentioned method (3) to mix solid phase and concentrated liquid to feed black soldier flies, which can further reduce the feed / fly ratio and increase output. Moreover, by adjusting the ratio of solid phase to concentrated liquid, the feed / fly ratio can reach up to 1:(0.3~0.32), which is the method with the highest output at present. This indicates that the nutrients in the concentrated liquid and solid phase complement each other. At the same time, the addition of concentrated liquid makes the solid phase softer and easier for black soldier flies to burrow into.

[0090] Examples 1 to 4 used the method described in (1) above, employing only the concentrated liquid as a nutrient source to feed black soldier flies. When mushroom waste, plastic granules, or rubber granules were used as support materials, the black soldier flies grew slowly or died, indicating that these support materials lacked necessary nutrients and contained toxic substances. While agricultural by-products and sawdust were used as support materials, the black soldier flies were able to grow and emerge, but the time required was much longer than when using a mixture of solid phase and concentrated liquid, indicating that these support materials provided a small amount of nutrition, but were insufficient to support the normal growth of the black soldier flies.

[0091] Example 5 uses the above (2) method to ferment the concentrate with grain by-products and lactic acid bacteria to feed black soldier flies. This achieves the synergistic and comprehensive utilization of various organic waste resources, reduces resource waste, makes the best use of resources, and the high-quality animal protein of insects can be used as a substitute product after bioconversion.

[0092] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for the resource utilization of concentrated kitchen waste liquid, characterized in that, Includes the following steps: After the kitchen waste is processed by three-phase centrifugation, the liquid phase is collected. After the liquid phase is subjected to directional fermentation and distillation to evaporate the small molecule organic matter, the remaining liquid after distillation is obtained, which is a concentrated liquid. The concentrate was used to feed saprophytic insect larvae; The concentrated solution is used for feeding in any one of the following methods (1) to (3): (1) Provide solid support material, the support material including at least one of straw and sawdust, attach the insect larvae to the support material, and add the concentrated liquid to the support material to feed the insect larvae; (2) The concentrate, grain by-products, and lactic acid bacteria are subjected to a second fermentation treatment, and the fermentation product is used to feed the insect larvae; (3) Collect the solid phase after the three-phase centrifugation treatment, mix the concentrate with the solid phase, and use the resulting mixture to feed the insect larvae.

2. The method according to claim 1, characterized in that: In the method described in (1), the particle size of the support material is 20 mesh or less.

3. The method according to claim 1 or 2, characterized in that: In the method described in (1); The feeding period is 8 to 15 days; And / or, the weight ratio of the concentrate to the adult insect produced by the insect larva is 1:0.10 to 0.

18.

4. The method according to claim 1, characterized in that: In method (2), the second fermentation treatment includes lactic acid fermentation; The temperature for the second fermentation treatment is 30–35°C; And / or, the second fermentation treatment lasts for 24 to 48 hours; And / or, the mass ratio of the concentrate, the grain by-product, and the lactic acid bacteria is 3-10:2-10:

1.

5. The method according to claim 1 or 4, characterized in that: In method (2) described above; The feeding period is 5 to 7 days; And / or, the weight ratio of the fermentation product to the adult insect produced by the insect larva is 1:0.2 to 0.

3.

6. The method according to claim 1, characterized in that: In the method described in (3), the mass ratio of the solid phase to the concentrate is 2 to 4:

1.

7. The method according to claim 1 or 6, characterized in that: In the method described in (3); Feeding time is 5 to 8 days; And / or, the weight ratio of the mixture to the adult insect produced by the insect larva is 1:0.24 to 0.

32.

8. The method according to any one of claims 1, 2, 4, and 6, characterized in that: The insect larvae include at least one of the following: black soldier fly, fly larvae, mealworm, and cockroach.

9. The method according to any one of claims 1, 2, 4, and 6, characterized in that: The concentrated solution has a water content of 70% to 80%.

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