Buried earthworm composting operation method based on photovoltaic heat supply

Abstract

The invention belongs to the technical field of organic waste treatment, and particularly relates to a buried earthworm composting operation method based on photovoltaic heat supply, which comprises the following steps: selecting a site; building a photovoltaic power supply and heat supply system; constructing a standardized composting ditch and a temperature increasing pipeline; mixed waste is filled, and humus is completed; putting earthworms; adding a microbial agent; and collecting earthworms and wormcast. According to the method, the photovoltaic panel and the solar water heater are laid above the composting ditch for sun shading, earthworm escape caused by exposure to the sun in the composting ditch is avoided, meanwhile, moisture volatilization is reduced, hot water generated by the solar water heater is used for heating the composting ditch, the humus speed is increased, and therefore earthworm composting treatment is efficiently carried out.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic waste treatment, and particularly relates to a buried earthworm composting method based on photovoltaic heat supply. BACKGROUND

[0002] As a large agricultural and livestock breeding province, Hebei produces a large amount of crop waste, livestock manure and the like every year, and the expansion of green belts along cities and traffic lines also causes the number of garden waste to increase rapidly, so how to realize the recycling of the organic waste becomes a problem to be solved.

[0003] Earthworms feed on organic waste such as crop waste and livestock manure, have a large digestion capacity and strong reproductive capacity, and can quickly convert organic waste into humus through mechanical grinding, digestive enzyme chemical digestion and microbial synergistic effect, thereby bringing good economic returns. The use of earthworm composting can effectively kill harmful substances such as E. coli, Staphylococcus and insect eggs in the waste, and the earthworm manure produced is rich in organic matter and beneficial microorganisms, and is a high-quality organic fertilizer for soil pollution prevention and remediation.

[0004] However, after the garden waste containing large particles such as branches and leaves and high-fiber substances is mixed, the humification time of the mixed waste is prolonged, the earthworm inoculation time is delayed, and the earthworm composting treatment cannot be efficiently performed. SUMMARY

[0005] The application provides a buried earthworm composting method based on photovoltaic heat supply, which can ferment mixed waste by a solar heat collection method, accelerate the humification speed, and improve the operation efficiency of earthworm composting.

[0006] The application adopts the following specific technical scheme:

[0007] A buried earthworm composting method based on photovoltaic heat supply comprises the following steps,

[0008] S1. Site selection;

[0009] S2. Construction of a photovoltaic power supply and heat supply system;

[0010] S3. Construction of a standardized composting ditch and a temperature increasing pipeline;

[0011] S4. Filling of mixed waste and completion of humification;

[0012] S5. Earthworm inoculation;

[0013] S6. Addition of a microbial agent;

[0014] S7. Harvesting of earthworms and earthworm manure.

[0015] The photovoltaic power supply and heating system includes photovoltaic panels and solar water heaters installed above the composting ditch. In step S3, after the composting ditch is opened, a hot water pipe is laid at the bottom of the composting ditch as a heating pipe. The hot water pipe is connected to the water inlet and outlet of the solar water heater to form a water circulation.

[0016] The ratio of the width to the depth of the compost trench in step S3 is 5:8.

[0017] In step S4, the C / N ratio of the mixed waste is 1:25-40, the mixed waste is piled 10 cm above the ground, and a micro-spraying tape is laid on the top and then covered with a film.

[0018] In step S5, earthworms are released through an earthworm seedling tower, which includes a release tube with a through hole on the side wall and a liquid collecting hopper with an inverted funnel structure. The bottom of the release tube is connected to the liquid collecting hopper through a filter screen, and a drainage tank is also provided. The drainage tank is connected to the liquid collecting hopper via a pipeline, and the drainage tank is connected to a suction pump.

[0019] In step S4, before the mixed waste is filled in, a supporting mesh is laid in the compost trench, and the supporting mesh is wrapped around the side walls and the bottom of the compost trench.

[0020] Step S7 completes the harvesting with the help of an earthworm harvester. The earthworm harvester includes a frame, a scraper conveyor belt arranged at the front end of the frame, and a drum screen arranged at the rear end of the frame. The front end of the scraper conveyor belt is tilted downward to form a material input end, and the rear end is tilted upward to form a material output end and connected with the inlet of the drum screen. The side wall of the drum screen is provided with a through hole for earthworm castings to pass through, and the remaining fresh earthworms are discharged from the tail end of the drum screen.

[0021] The belt surface of the scraper conveyor belt has the freedom to rotate from bottom to top, and a material comb with strip-shaped protrusions is provided on the belt surface. The drum screen forms a rolling fit with the frame by means of a supporting roller.

[0022] The frame is also provided with a cloth pulling device, which includes a cloth lifting roller, a first support wheel, a second support wheel and a pair of squeezing rollers arranged in sequence along the forward direction of the frame. A gathering hopper is provided below the drum screen, and the first support wheel and the second support wheel are arranged on the central axis of the gathering hopper. The supporting mesh passes through the cloth lifting roller, the first support wheel, the second support wheel and the pair of squeezing rollers in sequence.

[0023] The beneficial effects of the present invention are:

[0024] The present invention adopts the method of laying photovoltaic panels and solar water heaters above the composting ditch for sunshade, so as to prevent the composting ditch from being exposed to the sun and causing earthworms to escape, and at the same time reduce water volatilization. The hot water generated by the solar water heater is used to heat the composting ditch, accelerate the humification speed, and thus efficiently carry out earthworm composting treatment. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A flowchart of the method of the present application is shown in the figure;

[0026] Figure 2 A schematic diagram of the compost trench is shown in the figure;

[0027] Figure 3 A schematic diagram of the structure of the earthworm harvester is shown in the figure;

[0028] Figure 4 A schematic diagram of the layout of the cloth pulling device is shown in the figure;

[0029] Figure 5 A schematic diagram of the earthworm harvester in operation is shown in the figure;

[0030] In the drawings, 1 is a compost trench, 2 is a hot water pipe, 3 is a feeding pipe, 4 is a liquid collecting hopper, 5 is a drainage tank, 6 is a supporting mesh, 7 is a frame, 8 is a scraping conveyor belt, 9 is a drum screen, 10 is a material comb, 11 is a cloth lifting roller, 12 is a first supporting wheel, 13 is a second supporting wheel, and 14 is a squeezing roller pair. DETAILED DESCRIPTION

[0031] The present application will be further described below in conjunction with the drawings and specific embodiments:

[0032] Specific embodiments are shown in the drawings, and the present application discloses a buried earthworm composting method based on photovoltaic heating, comprising the following steps, Figure 1 and Figure 2 As shown in the drawings, the present application discloses a buried earthworm composting method based on photovoltaic heating, comprising the following steps,

[0033] S1. Site selection; select general farmland or forest land outside basic farmland, and the policy allows the construction of photovoltaics, and the land rent is cheap; a scale of 30 mu is more appropriate, and preferably the selected composting point has an organic waste supply source within a range of 10 kilometers, thereby reducing transportation costs.

[0034] S2. Construction of photovoltaic power supply and heating system; photovoltaic panels and solar water heaters are built on the space above the compost trench 1, which not only meets the needs of production for electricity and heat sources, but also generates good economic benefits by feeding excess electricity into the grid. The current distributed photovoltaic investment recovery period is 3-5 years.

[0035] S3. Construction of standardized compost trench 1 and temperature increasing pipeline;

[0036] S4. Fill in mixed waste and complete humification;

[0037] S5. Earthworm release; 1-3 cm long earthworm seedlings are selected for release.

[0038] S6. Add microbial inoculant;

[0039] S7. Harvesting earthworms and earthworm manure.

[0040] In the present application, the preparation method of the microbial agent is as follows: 1 liter of pure earthworm manure after screening out impurities is added with 50 times volume of pure water, then 20-30 ml of sugarcane molasses is added, the mixture is uniformly mixed, then is put into an aeration device for oxygenation for 24 hours, then is statically rested for 2 hours, and then is filtered through an 80-mesh screen to become the microbial agent, which can be directly sprayed in the earthworm composting ditch 1, significantly reducing the residual anaerobic bacteria in the waste in the anaerobic fermentation and maturation stage, making the earthworm-favored microbial population rapidly reproduce into the dominant population, and significantly accelerating the composting process.

[0041] The microbial agent can be produced on a large scale on site. The earthworm composting waste can be continuously added through a micro-spraying belt to form a high-efficiency earthworm composting system. In addition, the nitrogen, phosphorus and potassium contents in the new earthworm manure are increased after inoculation of the microbial agent, and the earthworm manure with high nutritional value is produced.

[0042] In the present application, a composting ditch 1 with a length of 200 meters, a width of 50 cm and a depth of 80 cm is constructed per mu of land, 60 tons of mixed organic waste are filled in each time, the humification time is 20 days, and the digestion cycle is 14 days after the earthworm seedlings are put in. The cycle is performed 6 times per year, 300 tons of waste can be treated per year, 150 tons of earthworm manure, 3000 kg of fresh earthworms are produced per mu of land per year, the earthworm manure is worth 150X200 yuan / ton, the earthworms are sold for 3000X10 yuan / kg, the total income is 60000 yuan, the labor cost is 15000 yuan, the water and electricity cost is 4000 yuan, and the equipment depreciation is 3000 yuan, so the income per mu of land is 38000 yuan, the net income per ton of waste is 127 yuan. A photovoltaic power of 60 kW can be constructed per mu of land, each watt needs an investment of 3.0 yuan, the total investment is 180000 yuan, 65000 degrees of electricity are generated per year, the on-grid electricity price is 0.4 yuan / degree, the income is 26000 yuan, and the net income per year is 17000 yuan during the period of power generation. The total income per mu of land per year is 55000 yuan.

[0043] At present, the straw in rural areas is basically crushed and backfilled for disposal, which avoids the pollution of burning to the environment, but has obvious disadvantages. Since the landfill depth is shallow and there is no land rotation system, it is easy to cause the lodging and yield reduction of the next season crops, and the insect eggs in the straw cannot be effectively killed, so the use of pesticides cannot be avoided, forming a vicious cycle. The straw treated by earthworm digestion can completely avoid such hazards. The rural toilet biogas residue, garden waste and branches and leaves also have a nearby collection and treatment place.

[0044] The earthworm composting method of the present application can be used to construct a farm and photovoltaic complementary earthworm biological composting plant every 20000 mu of farmland, to realize the centralized utilization of straw and organic waste within a range of 10 kilometers, and to return the earthworm manure organic fertilizer to the farmland to gradually restore the soil ecology, which is a long-term sustainable project with good economic benefits and becomes a new representative of productivity in the agricultural field.

[0045] Furthermore, the photovoltaic power supply and heating system of the present invention includes photovoltaic panels and solar water heaters installed above the compost ditch 1. In step S3, after the compost ditch 1 is opened, a hot water pipe 2 is laid at the bottom of the compost ditch 1 as a warming pipe, and the hot water pipe 2 is connected to the water inlet and outlet of the solar water heater to form a water circulation.

[0046] In step S3, the width-to-depth ratio of the compost trench 1 is 5:8. A trencher is used to create a 50-by-80-centimeter trench in the field. The trench's length is determined by the plot's shape, with a total trench length of 200 meters per mu (approximately 200 meters). Three 4-inch diameter PVR hot water pipes 2 are laid on either side of the trench. These pipes, combined with a solar water heater, rapidly heat the material within the compost trench 1 to above 50°C, thereby rapidly initiating the humification process and shortening the fermentation time. After fermentation is complete, cold water is introduced into the hot water pipes 2 to cool the temperature within the trench to 23-27°C, a temperature ideal for earthworm growth.

[0047] In step S4, the C / N ratio of the mixed waste is 1:25-40. The mixed waste is piled 10 cm above the ground, and a micro-sprinkler tape is laid on top before being covered with a film. A spreading machine mixes various wastes, such as straw, garden waste, livestock and poultry manure, biogas residue, and manure tank sludge. The mixture is then filled into the trench, topped with a micro-sprinkler tape, and finally covered with a film using a film laminating machine. This rapidly humifies the waste in the trench through increased heating and humidification.

[0048] In step S5, earthworms are released through an earthworm seedling tower. The earthworm seedling tower includes a delivery pipe 3 with a through-hole on its side wall and a liquid collecting hopper 4 in an inverted funnel structure. The bottom of the delivery pipe 3 is connected to the liquid collecting hopper 4 through a filter screen. A drainage tank 5 is also provided. The drainage tank 5 is connected to the liquid collecting hopper 4 via a pipeline. The drainage tank 5 is connected to a suction pump. The suction pump creates a negative pressure in the drainage tank 5, thereby extracting the liquid in the liquid collecting hopper 4 via the pipeline and temporarily storing it in the drainage tank 5. When the drainage pipe 5 is full, the liquid can be taken out and used as liquid fertilizer.

[0049] The delivery tubes 3 are inserted into the compost trench 1 at intervals of 1-1.5 meters. These tubes are made of PVC plastic pipes with a diameter of 10 cm and a length of 100 cm. A conical bottom hopper 4 is connected to a drainage tank 5. The delivery tubes 3 have 1-3 mm diameter holes cut into the sidewalls from the bottom to the top, forming a mesh-like structure. The tubes are filled with an 80 cm high mixture of peat, coconut coir, and paper pulp, along with 10,000 earthworms, each 1-3 cm long.

[0050] The earthworm seedling tower is pressed into the ditch for about 3-5 days. As the food in the tube is digested and the earthworms gradually adapt to the surrounding environment, the earthworms will actively spread through the through holes of the delivery tube 3 to the surrounding area and enter the waste to feed. The seedling delivery is completed. After the earthworm seedlings leave the earthworm tower, the earthworm tower inserted into the ditch still plays an important role. It can increase the permeability of the ditch and provide sufficient oxygen for microorganisms. When the leachate in the ditch is too high, the leachate at the bottom can be automatically collected and retained until the earthworms are harvested for recycling.

[0051] The porous delivery pipe 3 can simultaneously increase the air permeability in the composting trench 1 during the composting process and promptly remove the accumulated liquid at the bottom, thus completely solving the potential risks of flooding and poor air permeability.

[0052] After the earthworm seedlings are put in, microbial agents made from earthworm castings are immediately sprayed into the waste through the micro-spraying belt on the top of the composting ditch 1, so that the population of beneficial microorganisms in the ditch increases rapidly, which has the effect of adding starter bait to the earthworm seedlings.

[0053] Furthermore, in step S4, before the mixed waste is filled into the compost trench 1, a support mesh 6 is laid. The support mesh 6 is wrapped around the sidewalls and bottom of the compost trench 1. The support mesh 6 is permeable to the filtrate, thereby preventing the waste from being too high in moisture and causing the earthworms to drown, and also preventing the earthworms from escaping.

[0054] Step S7 completes the harvesting with the help of an earthworm harvester. The earthworm harvester includes a frame 7, a scraper conveyor belt 8 arranged at the front end of the frame 7, and a drum screen 9 arranged at the rear end of the frame 7. The front end of the scraper conveyor belt 8 is tilted downward to form a material input end, and the rear end is tilted upward to form a material output end and connected with the inlet of the drum screen 9. The side wall of the drum screen 9 is provided with a through hole for earthworm castings to pass through, and the remaining fresh earthworms are discharged from the tail end of the drum screen 9.

[0055] The frame 7 is provided with running wheels, which straddle both sides of the composting ditch 1 .

[0056] The scraper conveyor belt 8 has the freedom to rotate from bottom to top thanks to the drive motor. A strip-shaped protruding material comb 10 is provided on the belt surface. The drum screen 9 forms a rolling fit with the frame 7 via support rollers. At least one set of support rollers of the drum screen 9 is connected to a drive motor, and the rotation of the drive motor enables the drum screen 9 to have the freedom to rotate.

[0057] The frame 7 is also provided with a cloth pulling device, which includes a cloth lifting roller 11, a first support wheel 12, a second support wheel 13 and an extrusion roller 14 arranged in sequence along the forward direction of the frame 7. A collecting hopper is provided below the drum screen 9, and the first support wheel 12 and the second support wheel 13 are arranged on the central axis of the collecting hopper. The supporting mesh cloth 6 passes through the cloth lifting roller 11, the first support wheel 12, the second support wheel 13 and the extrusion roller 14 in sequence.

[0058] like Figure 5 As shown, when the earthworm harvester is harvesting earthworms, it first lifts the edge of the supporting mesh 6 exposed at the end of the compost ditch 1, and passes it through the cloth lifting roller 11, the first support wheel 12, the second support wheel 13 and the squeezing roller 14 in sequence, wherein the cloth lifting roller 11 is connected to a drive motor for lifting the supporting mesh 6 and approaching the input end of the scraper conveyor belt 8, and the squeezing roller 14 is also connected to a drive motor, which clamps and pulls the supporting mesh 6 through the squeezing roller 14. As the earthworm harvester moves forward, the squeezing roller 14 pulls the supporting mesh 6 to lift it, so that the material in the compost ditch 1 is pulled out of the ditch along with the supporting mesh 6 and is scraped into the drum screen 9 by the scraper conveyor belt 8, thereby ensuring that all the materials are collected. As the material is fed into the drum screen 9, the earthworm castings and material particles are thrown out from the side wall of the drum screen 9 to the funnel-shaped gathering hopper. Below the discharge port of the gathering hopper is the conveying path of the supporting mesh 6. The supporting mesh 6 at the gathering hopper position is supported by the first supporting wheel 12 and the second supporting wheel 13. The first supporting wheel 12 and the second supporting wheel 13 are located at the center line of the supporting mesh 6, so that the supporting mesh 6 is ridge-shaped. The fallen material (i.e. earthworm castings) slides to both sides of the composting ditch 1 with the help of the supporting mesh 6 to avoid falling back into the ditch for easy collection. The large particles of impurities and earthworms that cannot pass through the sieve are discharged and collected through the tail opening of the drum screen 9. The large particles of impurities can be picked out manually, and fresh earthworms are sold as commodities.

Claims

1. A method for underground earthworm composting based on photovoltaic heating, characterized by: The following steps are included: S1. Site selection; S2. Construction of photovoltaic power supply and heating system; S3. Construction of standardized composting trench (1) and heating pipeline; S4. Fill in mixed waste and complete humification; S5. Release earthworms; S6. Adding microbial agents; S7. Harvesting earthworms and vermicompost.

2. The underground earthworm composting method based on photovoltaic heating according to claim 1, characterized in that: The photovoltaic power supply and heating system comprises a photovoltaic panel and a solar water heater installed above the compost ditch (1). In step S3, after the compost ditch (1) is opened, a hot water pipe (2) is laid at the bottom of the compost ditch (1) as a heating pipe. The hot water pipe (2) is connected to the water inlet and outlet of the solar water heater to form a water circulation.

3. The underground earthworm composting method based on photovoltaic heating according to claim 1, characterized in that: The ratio of the width to the depth of the compost trench (1) in step S3 is 5:

8.

4. The underground earthworm composting method based on photovoltaic heating according to claim 1, characterized in that: In step S4, the C / N ratio of the mixed waste is 1:25-40, the mixed waste is piled 10 cm above the ground, and a micro-spraying tape is laid on the top and then covered with a film.

5. The underground earthworm composting method based on photovoltaic heating according to claim 1, characterized in that: In step S5, earthworms are released through an earthworm seedling tower, which includes a release pipe (3) with a through hole set on the side wall and a liquid collecting hopper (4) with an inverted funnel structure. The bottom of the release pipe (3) is connected to the liquid collecting hopper (4) through a filter screen, and a drainage tank (5) is also provided. The drainage tank (5) is connected to the liquid collecting hopper (4) via a pipeline, and the drainage tank (5) is connected to a suction pump.

6. The underground earthworm composting method based on photovoltaic heating according to claim 1, characterized in that: In step S4, before the mixed waste is filled in, a supporting mesh cloth (6) is laid in the compost trench (1), and the supporting mesh cloth (6) is wrapped around the side wall and the bottom of the compost trench (1).

7. The underground earthworm composting method based on photovoltaic heating according to claim 6, characterized in that: Step S7 completes harvesting with the aid of an earthworm harvester, the earthworm harvester comprising a vehicle frame (7), a scraper conveyor belt (8) arranged at the front end of the vehicle frame (7), and a drum screen (9) arranged at the rear end of the vehicle frame (7), wherein the front end of the scraper conveyor belt (8) is tilted downward to form a material input end, and the rear end is tilted upward to form a material output end and connected to the inlet of the drum screen (9), and the side wall of the drum screen (9) is provided with a through hole for earthworm castings to pass through, and the fresh earthworms remaining after screening are discharged from the rear end of the drum screen (9).

8. The underground earthworm composting method based on photovoltaic heating according to claim 7, characterized in that: The belt surface of the scraper conveyor belt (8) has the freedom to rotate from bottom to top, and a strip-shaped protruding material comb (10) is provided on the belt surface. The drum screen (9) forms a rolling fit with the frame (7) by means of a supporting roller.

9. The underground earthworm composting method based on photovoltaic heating according to claim 7, characterized in that: The frame (7) is also provided with a cloth pulling device, which includes a cloth lifting roller (11), a first support wheel (12), a second support wheel (13) and an extrusion roller (14) arranged in sequence along the forward direction of the frame (7); a collecting hopper is provided below the drum screen (9); the first support wheel (12) and the second support wheel (13) are arranged on the central axis of the collecting hopper; the supporting mesh cloth (6) passes through the cloth lifting roller (11), the first support wheel (12), the second support wheel (13) and the extrusion roller (14) in sequence.

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