Method for simultaneously realizing innocent treatment and resource utilization of silkworm manure and cocoon cooking wastewater

Abstract

The invention discloses a method for simultaneously realizing innocent treatment and resource utilization of silkworm excrement and cocoon cooking wastewater, which comprises the following steps: mixing silkworm excrement and cocoon cooking wastewater in proportion, carrying out heat preservation treatment, separating to obtain silkworm excrement filter residues and silkworm excrement water extract, mixing silkworm excrement with vegetable garden soil, inoculating chlorella in the water extract, culturing and separating, and then adding the chlorella into the silkworm excrement filter residues and the silkworm excrement water extract to obtain the innocent treatment and resource utilization of the silkworm excrement and cocoon cooking wastewater. The algae cells are used for preparing compound aquatic feed. The method has the advantages of effectively preventing silkworm excrement, cocoon cooking wastewater and other silkworm industry wastes from polluting the environment, converting resource advantages into economic advantages, having important significance for deeply developing a silkworm industry chain and promoting formation of a circular economy mode, and being beneficial to environmental protection. Besides, the silkworm manure fertilizer developed by the invention can obviously promote the growth of vegetables, the developed aquatic feed can obviously improve the growth rate and the survival rate of aquatic animals such as fishes, and the method established by the invention has the characteristics of high conversion efficiency, good product effect, simplicity and convenience in operation and the like, and is easy to realize industrial large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection and comprehensive resource utilization, and relates to a comprehensive utilization method of sericulture waste, specifically a method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater. Background Art

[0002] Silkworm excrement theoretically refers to the excrement of silkworms after they eat mulberry leaves, but in the actual production process, silkworm excrement is usually collected together with the remaining mulberry leaves and silkworm bedding. Silkworm excrement contains a large number of pathogens such as nuclear polyhedrosis virus, cytoplasmic polyhedrosis virus, Beauveria bassiana, microsporidia, Aspergillus spores, etc., which are highly pathogenic and contagious, and are one of the main sources of infection and epidemic of silkworm diseases in silkworm areas. With the rapid development of the sericulture industry and the increasing production volume, silkworm diseases have broken out in some silkworm areas due to the random dumping or improper handling of silkworm excrement, causing significant economic losses to silkworm farmers, thereby increasing the risk and instability of silkworm farmers in the mulberry silk industry, reducing their production enthusiasm, and being unfavorable to the sustainable development of the mulberry silk industry. Therefore, the prevention and control of silkworm excrement pollution in the mulberry silk industry has become the top priority for the sustainable, healthy and stable development of the mulberry silk industry. However, the current utilization of silkworm excrement is mostly in a shallow agricultural state, mainly as agricultural fertilizer. How to effectively control the spread of pathogens in silkworm feces and environmental pollution, and help silkworm farmers find effective, simple and easy methods to prevent and control silkworm feces pollution and utilize them as resources, is an urgent need to purify the silkworm breeding environment, reduce silkworm breeding risks, and increase silkworm farmers' income.

[0003] Silk reeling enterprises are major water users and wastewater dischargers. A large amount of medium to high concentration organic wastewater is generated in the production links such as cocoon boiling and silk reeling. The pollutants mainly include sericin protein, pupae protein, pigments and fatty acids.

[0004] Fully explore the multiple functions of silkworm manure and silk reeling wastewater, correctly grasp the development direction of diversified development and utilization of silkworm manure and silk reeling wastewater resources, understand their relationship with the traditional sericulture industry, establish a diversified development and utilization model for silkworm manure and silk reeling wastewater, and construct a technical system that adapts to the diversified development and utilization of silkworm manure and silk reeling wastewater resources. This will not only promote the further diversified development and utilization of silkworm manure and silk reeling wastewater resources, but also generate a strong driving force for the development of the sericulture industry. Summary of the invention

[0005] Technical problem to be solved: In order to overcome the deficiencies of the prior art, an effective, high value-added method for comprehensive utilization of sericulture waste is obtained; in view of this, the present invention provides a method for simultaneously achieving harmless treatment and resource utilization of silkworm feces and cocoon cooking wastewater.

[0006] Technical solution: A method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater, the method comprising the following steps:

[0007] S1, mix silkworm excrement and cocoon cooking wastewater in a mass g: volume mL ratio of 1:5-1:50, stir evenly, keep warm at 80-90°C for 1-6 hours, and then cool to room temperature;

[0008] S2, extruding the mixture obtained in S1 by a screw extruder to obtain silkworm excrement residue and silkworm excrement water extract respectively;

[0009] S3, performing pathogen detection on the silkworm feces filter residue and silkworm feces water extract obtained in S2;

[0010] S4, mixing the silkworm excrement filter residue collected in S2 with garden soil in a mass ratio of 1:1-1:2 for growing vegetables;

[0011] S5, inoculate the silkworm feces water extract collected in S2 with Chlorella vulgaris at a density of 10 4 -10 5 cells / mL, the culture temperature is 25°C, the light intensity is 3000 lux, and the Chlorella culture solution is obtained after 3-5 days of culture;

[0012] S6. Separate the Chlorella culture solution collected in S5 into algae and water. The algae are used to prepare compound aquatic feed, and the separated water is directly discharged into natural water bodies.

[0013] Preferably, the total nitrogen content of the cocoon-boiling wastewater in S1 is 203.2±4.48 mg / L, the total phosphorus content is 18.2±0.11 mg / L, the COD content is 2535.0±4.48 mg / L, and the temperature is 90-100° C. The silkworm feces are the excrement of silkworms, or the excrement, the leftover mulberry leaves and the silkworm bedding.

[0014] Preferably, the speed of the screw extruder in S2 is 50-100 r / min, and the gap between the extruder bars is 1-2 mm.

[0015] Preferably, in S3, plate colony counting method or polymerase chain reaction is used to detect pathogens.

[0016] Preferably, the Chlorella in S5 is Chlorella pyrenoidosa, Chlorella sorokinensis or Chlorella vulgaris.

[0017] Preferably, the composite aquatic feed in S6 comprises, by weight: 20-25 parts of algal cells, 20-25 parts of fish meal, 15-20 parts of soybean meal, 15-20 parts of corn flour, 10-15 parts of silkworm pupa powder, and 1-2 parts of complex vitamins.

[0018] Preferably, the vitamin complex, by weight, includes: B 12 20-25 parts of A, 50-60 parts of C, 20-30 parts of E.

[0019] Preferably, the pathogen detection rate is lower than 2.0%.

[0020] Preferably, the plant height increase rate is higher than 37%.

[0021] Preferably, the mortality rate of aquatic animals is lower than 0.5%, the average daily growth rate of aquatic animals is higher than 0.3%, and the morbidity rate of aquatic animals is lower than 1.8%.

[0022] The principle of the method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater of the present invention is as follows: (1) cocoon cooking wastewater at 90-100°C is mixed with silkworm excrement to kill pathogens in the silkworm excrement while preparing silkworm excrement water extract, thereby reducing the risk of pathogens polluting the environment during use; and this process can be completed directly by silkworm farmers, reducing the cost of intermediate processes such as silkworm excrement collection, transportation, and storage, as well as the possible leakage and spread risks. (2) The total phosphorus content in cocoon cooking wastewater is only 18.2±0.11 mg / L, which is far lower than the demand for phosphorus source for microalgae. After mixing with silkworm excrement, the phosphorus content in the silkworm excrement water extract can be significantly increased, the nitrogen-phosphorus ratio can be improved, and the obtained silkworm excrement water extract is more suitable as a culture medium for microalgae, thereby solving the technical problems such as high cost and large water consumption faced in the process of microalgae cultivation. (3) Microalgae are used to transform valuable resources such as carbon, nitrogen, and phosphorus in silkworm manure and cocoon-boiling wastewater, and the obtained microalgae biomass is developed into aquatic feed. While improving the resource utilization efficiency of silkworm manure and cocoon-boiling wastewater, their pollution to the environment is reduced, and the diversified utilization channels of sericulture industry by-products are broadened. (4) After pathogen detection, the obtained silkworm manure filter residue is developed into a compound fertilizer, which not only optimizes the fertility of silkworm manure filter residue, but also greatly reduces the risk of pathogen transmission caused by the application of silkworm manure organic fertilizer. Therefore, compared with the existing technology, the technical process provided by the present invention has obvious economic, social and environmental benefits, has a large industrial application prospect, and can be promoted and applied in many silkworm farmers.

[0023] Beneficial effects: (1) The method of the present invention can not only effectively control the spread of pathogens and environmental pollution in silkworm excrement, reduce the pollution of silkworm excrement to the environment, but also significantly reduce the content of environmental pollutants such as nitrogen and phosphorus in silkworm excrement and cocoon-making wastewater, meet the needs of diversified development and utilization of silkworm excrement and cocoon-making wastewater, and improve the comprehensive economic benefits of sericulture production. (2) The method can significantly reduce the content of total nitrogen, total phosphorus, and COD in silkworm excrement and cocoon-making wastewater, which not only helps to avoid the eutrophication of rivers, lakes and other water bodies, realize the resource utilization of sericulture industry waste, but also purify the silkworm breeding environment and increase the income of silkworm farmers. (3) The method is highly practical and easy to achieve industrial scale-up. It can not only save a lot of water resources and nutrients, but also greatly reduce the production cost of large-scale cultivation of microalgae, which is conducive to the industrialization process of microalgae cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of a method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater. DETAILED DESCRIPTION

[0025] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, modifications and substitutions made to the method, steps or conditions of the present invention all belong to the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0026] Examples 1-9

[0027] A method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater, the method comprising the following steps:

[0028] S1, silkworm excrement and cocoon cooking wastewater are mixed in a mass (g): volume (mL) ratio of 1:5-1:50, stirred evenly, kept warm at 80-90°C for 1-6 hours, and then cooled to room temperature;

[0029] S2, extruding the mixture obtained in S1 by a screw extruder to obtain silkworm excrement residue and silkworm excrement water extract respectively;

[0030] S3, performing pathogen detection on the silkworm feces filter residue and silkworm feces water extract obtained in S2;

[0031] S4, mixing the silkworm excrement filter residue collected in S2 with garden soil in a mass ratio of 1:1-1:2 for growing vegetables;

[0032] S5, inoculate the silkworm feces water extract collected in S2 with Chlorella vulgaris at a density of 10 4 -10 5 cells / mL, the culture temperature is 25°C, the light intensity is 3000 lux, and the Chlorella culture solution is obtained after 3-5 days of culture;

[0033] S6. Separate the Chlorella culture solution collected in S5 into algae-water separation. The algae are used to prepare compound aquatic feeds, and the separated water can be directly discharged into natural water bodies.

[0034] The speed of the screw extruder in S2 is 50-100r / min, and the gap between the extruder bars is 1-2mm. The chlorella in S5 is pyrenoid chlorella, sorokin chlorella or common chlorella. The composite aquatic feed in S6 includes, by weight: 20-25 parts of algal cells, 20-25 parts of fish meal, 15-20 parts of soybean meal, 15-20 parts of corn flour, 10-15 parts of silkworm pupa powder, and 1-2 parts of composite vitamins. The composite vitamins, by weight, include: B 1220-25 parts of A, 50-60 parts of C, 20-30 parts of E.

[0035] The above important parameters and corresponding test results are shown in Table 1.

[0036] Comparative Example 1

[0037] (1) Silkworm feces and tap water were mixed in a ratio of 1:15 (w / v) (g / mL) and left at room temperature for 4 hours;

[0038] (2) using a screw extruder (rotating speed of 100 r / min, and a screw bar gap of 2 mm) to extrude the mixture of silkworm feces and tap water obtained in (1) to obtain silkworm feces filtrate and silkworm feces water extract, respectively;

[0039] (3) The silkworm feces filtrate and silkworm feces water extract obtained in (2) were tested for pathogenic bacteria using plate colony counting method and polymerase chain reaction (PCR) method;

[0040] (4) mixing the silkworm feces filtrate obtained in (2) with garden soil in a ratio of 1:1.5 (w / w), and using the mixture for growing water spinach;

[0041] (5) inoculating Chlorella sorokinensis into the silkworm feces water extract obtained in step (2), analyzing the growth characteristics of the microalgae, and obtaining a Chlorella culture solution;

[0042] (6) Separating the Chlorella culture solution obtained in (5) from algae and water to prepare a composite aquatic feed, the formula of which is shown in Table 1;

[0043] (7) Using microalgae biomass as an indicator, the growth status and transformation capacity of the microalgae in this comparative example were analyzed (Table 1);

[0044] (8) The effect of mixing the silkworm feces filtrate with the garden soil in this comparative example was evaluated by taking the increase in the height of the water spinach plant compared with the control group as an indicator (Table 1);

[0045] (9) The aquatic feed prepared in this comparative example was used to feed grass carp for 60 days, and the effects of the aquatic feed were compared using mortality, average daily growth rate and morbidity as indicators (Table 1).

[0046] Comparative Example 2

[0047] (1) Cool the on-site cocoon cooking wastewater from the silk reeling factory to room temperature;

[0048] (2) The pathogenic bacteria in cocoon-boiling wastewater were detected by plate colony counting method and polymerase chain reaction (PCR) method;

[0049] (3) inoculating Chlorella sorokinensis into cocoon-boiling wastewater, analyzing the growth characteristics of the microalgae, and obtaining Chlorella culture fluid;

[0050] (4) Separating the Chlorella culture solution obtained in (3) from algae and water to prepare a composite aquatic feed, the formula of which is shown in Table 1;

[0051] (5) Using microalgae biomass as an indicator, the growth status and transformation capacity of the microalgae in this comparative scheme were analyzed (Table 1);

[0052] (6) The aquatic feed prepared in this comparative example was used to feed grass carp for 60 days, and the effects of the aquatic feed were compared using mortality, average daily growth rate and morbidity as indicators (Table 1).

[0053]

[0054]

[0055]

Claims

1. A method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater, characterized in that: The method comprises the following steps: S1, mix silkworm excrement and cocoon cooking wastewater in a mass g: volume mL ratio of 1:5-1:50, stir evenly, keep warm at 80-90°C for 1-6 hours, and then cool to room temperature; S2, extruding the mixture obtained in S1 by a screw extruder to obtain silkworm excrement residue and silkworm excrement water extract respectively; S3, performing pathogen detection on the silkworm feces filter residue and silkworm feces water extract obtained in S2; S4, mixing the silkworm excrement filter residue collected in S2 with garden soil in a mass ratio of 1:1-1:2 for growing vegetables; S5, inoculate the silkworm feces water extract collected in S2 with Chlorella vulgaris at a density of 10 4 -10 5 cells / mL, the culture temperature is 25°C, the light intensity is 3000 lux, and the Chlorella culture solution is obtained after 3-5 days of culture; S6. The Chlorella culture fluid collected in S5 is separated into algae and water. The algae are used to prepare compound aquatic feed, and the separated water is directly discharged into natural water bodies.

2. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The total nitrogen content of the cocoon-boiling wastewater in S1 is 203.2±4.48mg / L, the total phosphorus content is 18.2±0.11mg / L, the COD content is 2535.0±4.48mg / L, and the temperature is 90-100℃.

3. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The speed of the screw extruder in S2 is 50-100r / min, and the gap between the extruder bars is 1-2mm.

4. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: In S3, pathogens were detected by plate colony counting or polymerase chain reaction.

5. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The chlorella in S5 is Chlorella pyrenoidosa, Chlorella sorokinensis or Chlorella vulgaris.

6. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The composite aquatic feed described in S6 includes, by weight: 20-25 parts of algal cells, 20-25 parts of fish meal, 15-20 parts of soybean meal, 15-20 parts of corn flour, 10-15 parts of silkworm pupa powder, and 1-2 parts of complex vitamins.

7. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 6, characterized in that: The compound vitamins, by mass, include: B 12 20-25 parts of A, 50-60 parts of C, 20-30 parts of E.

8. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The detection rate of pathogens was less than 2.0%.

9. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The plant height increase rate is more than 37%.

10. The method for simultaneously achieving harmless treatment and resource utilization of silkworm excrement and cocoon cooking wastewater according to claim 1, characterized in that: The mortality rate of aquatic animals is lower than 0.5%, the average daily growth rate of aquatic animals is higher than 0.3%, and the morbidity rate of aquatic animals is lower than 1.8%.

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