Method for treating the leachate feeding solution using black soldier flies

Abstract

The present invention discloses a method for treating perishable garbage leachate by using black soldier flies, comprising the following steps: step (1), collecting perishable garbage leachate and directly using it as a leachate feeding liquid; step (2), treating the leachate feeding liquid by using black soldier flies. By directly using perishable garbage leachate as a leachate feeding liquid, and then treating the leachate feeding liquid by using black soldier flies, not only does it not need to pre-ferment the perishable garbage leachate, but it also does not need to add other solid feeding auxiliary materials, which greatly saves investment and energy consumption, and can fully reuse the treated perishable garbage leachate, thereby achieving zero discharge of perishable garbage leachate. This method is a treatment method with low investment, low operating cost, and can achieve zero discharge of leachate.

Description

Technical Field

[0001] The invention relates to the field of perishable garbage leachate treatment, and in particular to a zero-discharge treatment method for perishable garbage leachate. Background Art

[0002] In recent years, with the acceleration of my country's urbanization process and the steady improvement of people's living standards, garbage classification has also been carried out in major cities in my country. With the gradual implementation of garbage classification, the amount of perishable garbage has increased dramatically and is showing an upward trend year by year. Perishable garbage accounts for about 50% of my country's domestic garbage, and the moisture content of perishable garbage is as high as over 90%. At garbage transfer stations and perishable garbage treatment stations, the initially collected perishable garbage needs to be separated into solids and liquids in the collection and storage hopper, generating a large amount of leachate.

[0003] Perishable garbage leachate has the characteristics of high inorganic salt content, rich organic matter, high ammonia nitrogen concentration, rich trace elements, etc. If it is not treated in time, it will cause great environmental pollution, etc. It needs complex biochemical treatment before it can meet the discharge standards. The existing biochemical treatment process is complicated, the equipment cost is high, and the operating energy consumption is large. In particular, there is currently no efficient and low-cost zero-emission treatment method.

[0004] Chinese utility model CN214990825U discloses a fully quantitative treatment device for perishable garbage leachate, including a mounting frame, the bottom inner wall of the mounting frame is fixedly connected to a liquid collecting pool, the outer walls on both sides of the liquid collecting pool are fixedly connected to support plates, a connecting frame is fixedly connected between the two support plates, the upper surface of the mounting frame is fixedly connected to a cylinder, and one end of the cylinder piston rod passes through the top of the mounting frame and is fixedly connected to a connecting plate. The utility model drives the shell and the destroying needle to move downward together through the cylinder, so that the destroying needle passes through the circular hole and punctures the garbage packaging bag so that the leachate of the garbage can flow out, and at the same time, the shell squeezes the garbage so that the leachate in the garbage can be fully discharged. This scheme realizes the collection of leachate, but the collected leachate is not processed, and the reduction of leachate is not achieved.

[0005] Chinese invention CN201510246522.4 discloses a method for treating restaurant kitchen waste sewage using black soldier flies, comprising: adding powdered water-absorbing plant materials accounting for 20-30% of the weight of the sewage to the restaurant kitchen waste sewage, and preliminarily fixing the sewage in the water-absorbing material; adding the water-absorbing plant materials mixed with the sewage to a black soldier fly breeding plate made of a gauze material, so that the black soldier fly larvae feed on the nutrients therein. This invention requires a large amount of water-absorbing plant materials, and feeds the black soldier fly larvae in a solid form, which is relatively costly.

[0006] The method for treating perishable garbage leachate with black soldier flies disclosed in Chinese invention CN112243956A comprises the following steps: step 1, using perishable garbage leachate to make leachate feed; step 2, treating the leachate feed with black soldier flies. The method requires that the perishable garbage leachate is made into a fermentation liquid, and then evenly mixed with a solid premix and fermented to make a leachate feed. The method is complex and requires two fermentations, that is, the leachate is collected and fermented into a fermentation liquid, and the fermentation liquid is mixed with a solid premix and fermented into a feed, and finally the feed can be used for black soldier fly breeding. At the same time, 30% of the mass percentage of solid premix needs to be added. The solid premix is ​​prepared from the following raw materials in the following mass proportions: 50 mass parts of wheat bran, 20 mass parts of rice bran, 40 mass parts of bean dregs, 25 mass parts of distiller's grains, and 15 mass parts of sawdust. In short, the method also feeds black soldier fly larvae with a solid form of feed. Summary of the invention

[0007] Based on the problems existing in the prior art, the purpose of the present invention is to provide a method for treating the leachate feeding solution using black soldier flies, so as to solve the problem that the current black soldier fly bioconversion leachate requires a lot of pretreatment, such as fermentation, and a large amount of specific solid mixed materials need to be added, resulting in complex processes and high costs. In short, the present invention is a simple, economical and effective zero-discharge treatment method for perishable garbage leachate.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] The method for treating perishable garbage leachate using black soldier flies is characterized by comprising the following steps:

[0010] Step (i), collecting perishable garbage leachate and directly using it as leachate feeding liquid;

[0011] Step (ii), using black soldier flies to process the leachate feeding liquid, includes placing porous medium fillers in uncovered feeding boxes, quantitatively transporting the leachate feeding liquid to the uncovered feeding boxes in a processing workshop, inoculating black soldier fly larvae, and screening black soldier fly larvae.

[0012] On the basis of adopting the above technical solutions, the present invention can adopt the following further technical solutions, or use these further technical solutions in combination:

[0013] A metering pump is used to quantitatively deliver the feeding solution to the uncovered feeding box, and the single delivery volume is controlled at 1 / 4 to 1 / 3 of the box volume.

[0014] A metering container is used to manually add porous medium fillers in a quantitative manner, and the volume of the material added at a single time is controlled at 1 / 4 to 1 / 3 of the box volume.

[0015] The porous medium filler is one or more of biochar, activated carbon, ceramsite, sepiolite, zeolite, and polyester porous filler.

[0016] Use 3rd-instar black soldier fly larvae (referring to black soldier fly larvae on the 5th to 7th day after hatching, which should have strong stress resistance and vitality, and the size of the insect colony is uniform), and the inoculation density is added at a ratio of one larva feeding 0.1 to 30 ml of leachate. The feeding and development cycle of the larvae is 5 to 21 days.

[0017] At the end of each feeding and development cycle, the larvae, insect sand and porous media filler are physically separated; the insect sand is used as organic fertilizer or soil conditioner, and the porous media filler is returned to the spreading stage.

[0018] The processing workshop adopts negative pressure ventilation and is equipped with deodorization equipment, the ventilation volume is not less than 8 times per hour, and the ambient temperature is controlled at 25-30° C. The light / dark cycle of the processing workshop is controlled to be 18 / 6h.

[0019] It can be seen from the technical solution provided by the present invention that the present invention provides a zero-emission treatment method for perishable garbage leachate, which has the beneficial effects of: by directly using the perishable garbage leachate for the leachate feeding liquid, and then treating the leachate feeding liquid with black soldier flies, not only is there no need to pre-ferment the perishable garbage leachate, but there is no need to add other solid feeding auxiliary materials, which greatly saves investment and energy consumption, and can fully reuse the treated perishable garbage leachate to achieve zero emission of perishable garbage leachate. It is a treatment method with low investment, low operating costs, and the ability to achieve zero emission of leachate. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professional and technical personnel in this field.

[0021] Example 1: Feeding Example Using Biochar as Porous Medium Filler

[0022] Step (i), collecting perishable garbage leachate and directly using it as leachate feeding liquid;

[0023] Step (ii), using black soldier flies to treat the leachate feeding liquid, comprising: using black soldier flies to treat the leachate feeding liquid by: filling porous medium fillers in an uncovered feeding box, quantitatively transporting the leachate feeding liquid to the uncovered feeding box in a processing workshop, inoculating black soldier fly larvae, and screening the black soldier fly larvae.

[0024] In this embodiment, the quantitative delivery of the feeding solution is: using a metering pump to quantitatively deliver the feeding solution to a 600ml uncovered feeding box, and the volume of the feeding solution delivered at a single time is controlled to be 1 / 3 of the volume of the box, that is, 200ml.

[0025] In this embodiment, the porous medium filler material is: a metering container is used to manually add the porous medium filler in a quantitative manner, and the volume of the material added at a single time is controlled to be 1 / 3 of the volume of the box, that is, 200 ml.

[0026] In this embodiment, the porous medium filler is biochar.

[0027] In this embodiment, the black soldier fly larvae are inoculated as follows: the black soldier fly larvae are used on the 6th day after hatching. The black soldier fly larvae should have strong stress resistance and vitality, and the size of the insect colony is uniform. The inoculation density is added at a ratio of 1 larva feeding 20 ml of leachate, that is, 20 larvae are added in an uncovered breeding box, and the feeding and development cycle of the larvae is 5 days.

[0028] In this embodiment, the black soldier fly larvae are screened as follows: at the end of each feeding development cycle, the larvae, insect sand and porous medium filler are physically separated. The insect sand is used as organic fertilizer or soil conditioner, and the porous medium filler is reused in the fabric stage. On the starting day of the feeding development cycle, the wet weight of all larvae is 25 mg, and there are 20 larvae; on the end day of the feeding development cycle, the wet weight of all larvae is 117 mg, and 6 larvae have died.

[0029] In this embodiment, the leachate feeding solution is treated with black soldier flies, the treatment workshop adopts negative pressure ventilation and is equipped with deodorization equipment, the ventilation volume is not less than 8 times per hour, and the ambient temperature is controlled at 25-30° C. The light / dark cycle of the treatment workshop is controlled to be 18 / 6h.

[0030] Example 2: Feeding Example Using Ceramsite as Porous Medium Filler

[0031] Step (i), collecting perishable garbage leachate and directly using it as leachate feeding liquid;

[0032] Step (ii), using black soldier flies to treat the leachate feeding liquid, comprising: using black soldier flies to treat the leachate feeding liquid by: filling porous medium fillers in an uncovered feeding box, quantitatively transporting the leachate feeding liquid to the uncovered feeding box in a processing workshop, inoculating black soldier fly larvae, and screening the black soldier fly larvae.

[0033] In this embodiment, the quantitative delivery of the feeding solution is: using a metering pump to quantitatively deliver the feeding solution to a 600ml uncovered feeding box, and the volume of the feeding solution delivered at a single time is controlled to be 1 / 3 of the volume of the box, that is, 200ml.

[0034] In this embodiment, the porous medium filler material is: a metering container is used to manually add the porous medium filler in a quantitative manner, and the volume of the material added at a single time is controlled to be 1 / 3 of the volume of the box, that is, 200 ml.

[0035] The porous medium filler is ceramsite.

[0036] In this embodiment, the black soldier fly larvae are inoculated as follows: the black soldier fly larvae are used on the 6th day after hatching. The black soldier fly larvae should have strong stress resistance and vitality, and the size of the insect colony is uniform. The inoculation density is added at a ratio of 1 larvae feeding 20 ml of leachate, that is, 20 larvae are added in the uncovered breeding box, and the feeding and development cycle of the larvae is 21 days.

[0037] In this embodiment, the black soldier fly larvae are screened as follows: at the end of each feeding development cycle, the larvae, insect sand and porous medium filler are physically separated. The insect sand is used as organic fertilizer or soil conditioner, and the porous medium filler is reused in the fabric link. On the starting day of the feeding development cycle, the wet weight of all 7-day-old larvae is 3480 mg, and the number of larvae is 1200; on the end day of the feeding development cycle, the wet weight of all larvae is 6530 mg, and 337 larvae have died.

[0038] In the above method, the leachate feeding solution is treated by black soldier flies, the treatment workshop adopts negative pressure ventilation and is equipped with deodorization equipment, the ventilation volume is not less than 8 times per hour, and the ambient temperature is controlled at 25-30° C. The light / dark cycle of the treatment workshop is controlled to be 18 / 6h.

Claims

1. Method for treating leachate of perishable garbage by using black soldier fly, characterized in that, it includes the following steps: Step (1), collect the leachate of perishable garbage and directly use it as the leachate feeding solution; Step (2), use black soldier fly to treat the leachate feeding solution, including laying porous medium fillers in an uncovered feeding box, quantitatively conveying the leachate feeding solution to the uncovered feeding box in the treatment workshop, inoculating black soldier fly larvae, and screening black soldier fly larvae; Use a metering pump to quantitatively convey the feeding solution to the uncovered feeding box, and control the single - time conveying volume to be 1 / 4 - 1 / 3 of the box volume; Use a metering container to manually add porous medium fillers quantitatively, and control the single - time laying volume to be 1 / 4 - 1 / 3 of the box volume; Use 3 - instar black soldier fly larvae, and add the inoculation density according to the ratio of 1 larva feeding on 0.1 - 30 ml of leachate. The feeding and development cycle of the larvae is 5 - 21 days.

2. The method for treating the leachate feeding solution by using black soldier fly according to claim 1, characterized in that: The porous medium filler is one or several of biochar, activated carbon, ceramsite, sepiolite, zeolite, polyester porous filler.

3. The method for treating the leachate feeding solution by using black soldier fly according to claim 1, characterized in that: At the end of each feeding and development cycle, physically separate the larvae, worm castings and porous medium fillers; the worm castings are used for organic fertilizers or soil conditioners, and the porous medium fillers are reused in the laying link.

4. The method for treating the leachate feeding solution by using black soldier fly according to claim 1, characterized in that: The treatment workshop adopts negative pressure ventilation and is equipped with deodorization equipment, the ventilation volume is not less than 8 times per hour, control the environmental temperature at 25 - 30 °C; control the light / dark cycle of the treatment workshop to be 18 / 6 h.