CN104430187A - Method for treating sludge in vermiculture - Google Patents

Abstract

The invention belongs to the field of sludge treatment, and relates to a method for treating sludge by earthworm breeding. After mixing the sludge with agricultural waste, it performs fermentation pretreatment, cools down, adds it to an earthworm breeding bed, and feeds and digests it through earthworms. Transform the sludge into vermicompost to obtain two products: earthworm and vermicompost. The vermiculture bed is surrounded by impermeable walls. layer and cultivation layer; perforated drainage pipes and perforated cloth air pipes are arranged at the bottom of the adjustment layer; the surface layer of the cultivation layer is a composite layer of straw curtains, ginkgo leaves and medicinal residues. The invention overcomes the defect that the existing earthworm sludge treatment technology has not yet formed a complete disposal system, and the provided method for earthworm breeding sludge treatment controls the pollution source in the sludge treatment process, improves the vitality of earthworms, and reduces the sludge treatment capacity. The increase has enabled the scale and standardization of field earthworm culture technology.

Description

Method for treating sludge by earthworm breeding

technical field

The invention belongs to the field of sludge treatment, and in particular relates to a method for treating sludge by earthworm breeding.

Background technique

my country's sludge treatment business started late, and the phenomenon of focusing on "water" and neglecting "mud" has existed for a long time. At present, less than a quarter of the existing sewage treatment industry has stable treatment facilities such as incineration, comprehensive utilization, and deep dehydration landfill. Less than 1/10 of the technology and supporting equipment are relatively complete, and few of them can operate normally; my country's traditional sludge independent landfill disposal technology has problems such as large infrastructure investment, low load, difficult operation and management, and lack of operating experience. . Mixed landfill with garbage has a great impact on the properties of the garbage dump, brings safety hazards to the garbage dump, and blocks the leachate collection system of the garbage dump. In my country's existing sewage treatment plants, according to the existing national standards, most of the sludge has not been properly disposed of; sludge disposal has become an important link that must be given priority in the design and operation of sewage treatment plants.

Earthworm sludge treatment technology is a method of sludge treatment using earthworms-microbial artificial ecosystems. It utilizes the ecological functions of earthworms to finally achieve sludge reduction and stabilization. Among them, the field earthworm breeding technology, because of its investment cost Low cost, easy management and other advantages have received more and more attention and application.

However, earthworm sludge treatment technology has not yet been applied on a large scale, and some key issues have not been resolved, such as sludge acceptance requirements, sludge pretreatment, parameter control during sludge disposal, product utilization, and establishment of pollution prevention and control systems etc. A complete set of disposal system has not yet been formed; at the same time, there is a lack of engineering examples of using earthworms to treat sludge, so more in-depth research is needed.

Contents of the invention

The purpose of the present invention is to overcome the defect that the existing earthworm sludge treatment technology has not yet formed a complete disposal system, to provide a sludge treatment process in which the pollution source is controlled, the vitality of the earthworms is improved, and the amount of sludge treatment is increased, which can realize large-scale And standardized methods of earthworm breeding sludge treatment.

The purpose of the present invention is achieved through the following technical solutions:

The method for treating sludge in earthworm breeding of the present invention is to mix the sludge with agricultural waste, carry out fermentation pretreatment, lower the temperature, add it to the earthworm breeding bed, and use it as the breeding food for earthworms to control the pH value of the earthworm breeding bed, temperature and humidity, through feeding and digestion by earthworms, the sludge is converted into vermicompost, and two products of earthworms and vermicompost are obtained. There is a top cover, and the vertical structure of the bed body in the wall (1) from the bottom to the upper part is an anti-seepage layer, an adjustment layer (2) and a culture layer (3); the adjustment layer (2) is a pebble layer, and the pebble layer Perforated drainage pipe (6) and perforated air distribution pipe (7) are arranged at the bottom of the layer, the perforated drainage pipe (6) is connected with the collection pool (8) outside the wall (1), and the perforated air distribution pipe (7) is connected with the perforated drainage pipe ( 6) are connected; there is a geotextile (9) between the adjustment layer (2) and the cultivation layer (3); the surface layer of the cultivation layer (3) is a composite layer of straw curtains, ginkgo leaves and medicinal residues; A wall-penetrating pipe head (10) is provided.

In the above solution, the agricultural waste is a mixture of one or more of farmland residues, orchard residues, residues from agricultural and by-product processing industries, and residues from food manufacturing.

In the above scheme, the farmland residues are residues of straw and vegetables; orchard residues are rotten fruits, fruit shells, branches and fallen leaves of fruit trees; residues in the agricultural and sideline product processing industry and residues in the food manufacturing industry For vegetable residues, fruit residues, mushroom residue and sawdust.

In the above scheme, the sludge is mixed with agricultural waste, the carbon-to-nitrogen ratio (C/N) is controlled at 20:1-30:1, and the moisture content is controlled at 40%-60%.

In the above solution, the lowermost layer of the anti-seepage layer is a compacted soil layer (4), and above the compacted soil layer is a modified bentonite layer or an anti-seepage membrane (5).

In the above scheme, the medicinal dregs are composed of hawthorn, scutellaria baicalensis, broccoli, malt and pulsatilla, with a weight ratio of 1:0.3~0.5:0.2~0.35:0.3~0.4:0.1~0.15.

In the above solution, the wall-piercing pipe head (10) is equipped with a plug (11).

In the above solution, the collection pool (8) is connected to the sewage treatment facility.

According to the method for treating earthworm breeding sludge of the present invention, the sludge to be treated is the sludge produced by urban domestic sewage treatment plants, in the production activities of animal husbandry, agricultural and sideline food processing industry, food manufacturing industry, wine, beverage and refined tea manufacturing industry The sludge generated from wastewater treatment can also be used to dispose of some agricultural waste. In the process of earthworm breeding, in order to ensure the best living environment for earthworms, temperature and humidity adjustment measures such as artificial water spraying are required. Therefore, part of the leachate will be generated at the bottom of the culture bed, and this part of leachate will be collected to the collection pool through pipelines. Because the lower part of the culture bed An anti-seepage system is installed, so it will not pollute the lower soil and groundwater; at the same time, some domestic sewage will be generated in the factory area. The wastewater is collected and sent to sewage treatment facilities for treatment. The treated wastewater meets the requirements of "Urban Sewage Recycling, Urban Miscellaneous Water Quality" (GB/T 18921) and is discharged to the clear water pool. After removing residual chlorine, it is used as water for humidity control and cooling of the breeding bed. Sewage treatment facilities should adopt secondary biological treatment process + advanced treatment process, and natural purification processes such as artificial wetlands and quick seepage pools can be used. During the sludge storage period and the fermentation pretreatment period, a large amount of odor will be produced, and its main components are sulfur-containing compounds and chlorine-containing compounds. The gas system enters the conditioning layer evenly, and the harmful components in the conditioning layer are absorbed and transformed by the biological communities attached to the pebbles to complete deodorization; due to the low gas flow rate in the bed, the harmful substances in the gas can be fully absorbed by the microorganisms in the conditioning layer , when it reaches the culture layer, the concentration is small and will not cause harm to earthworms. Before entering the adjustment layer, the gas can be humidified to increase the subsequent gas adsorption effect.

The beneficial effects of the present invention are:

1. Solved the problem of urban domestic sludge disposal, and can comprehensively utilize domestic sludge as a resource, reduce the damage and harm caused by sludge to the environment, and reduce the risk of high energy consumption, high pollution and high cost in the process of sludge treatment and disposal .

2. Reduce the pollution of agricultural waste. Straw and mushroom residues have become wastes that are difficult to dispose of in production areas, and their pollution is increasing day by day. However, the sludge produced by urban sewage treatment plants generally has a water content of about 80% and a low carbon-to-nitrogen ratio (C/N), which cannot meet the needs of initial composting and subsequent earthworm breeding. The invention adopts agricultural wastes such as straws and mushroom slags as the ingredients of the sludge, and the optimal proportion is determined through research, so that it is suitable for the needs of earthworm breeding, and both the sludge and the agricultural wastes are processed.

3. The disposal system of the present invention is completely matched, waste water and odor are treated, and secondary pollution is prevented.

4. The earthworm breeding bed of the present invention has good air permeability, is easy to control pH value, temperature and humidity, and the disease rate of earthworms is significantly reduced. Not only is the sludge treatment amount per unit area large, but also the earthworm proliferation rate is high, which is higher than that of traditional earthworm cultivation. Sludge treatment systems have clear advantages.

Therefore, the present invention overcomes the defect that the existing earthworm treatment sludge technology has not yet formed a complete disposal system, and the provided method for earthworm breeding and treatment sludge can control the pollution source in the sludge treatment process, the vitality of earthworms is improved, and the sludge The increase in processing capacity has enabled large-scale and standardized field earthworm culture technology.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Fig. 2 is a schematic diagram of the structure (section) of the earthworm breeding bed of the present invention.

Fig. 3 is a schematic diagram of the planar structure of the earthworm breeding bed of the present invention.

Fig. 4 is a flowchart of wastewater treatment and reuse in the present invention.

In the drawings, 1: wall; 2: regulation layer; 3: culture layer; 4: compacted soil layer; 5: modified bentonite layer or anti-seepage membrane; 6: perforated drainage pipe; 7: perforated air pipe; 8 : collection pool; 9: geotextile; 10: pipe head through the wall; 11: plug; 12: ground outside the wall; 13: fan.

specific embodiment

The present invention will be described in further detail below in conjunction with the drawings and embodiments, but the present invention is not limited to the embodiments.

Embodiment one

The method of treating sludge in the field cultured earthworms of this example is to mix the sludge with agricultural waste, carry out fermentation pretreatment, cool down, add it to the earthworm breeding bed, and use it as the breeding food for earthworms to control the pH value, temperature and humidity, through feeding and digestion by earthworms, the sludge is converted into vermicompost, and two products of earthworms and vermicompost are obtained. , the vertical structure of the bed in the wall 1 from the bottom to the upper part is an anti-seepage layer, an adjustment layer 2 and a culture layer 3; the adjustment layer 2 is a pebble layer, and the bottom of the pebble layer is provided with a perforated drainage pipe 6 and a perforated air distribution pipe 7 , the perforated drainage pipe 6 is connected with the collection pool 8 outside the body of wall 1, and the perforated air pipe 7 is connected with the perforated drainage pipe 6; there is a geotextile 9 between the regulating layer 2 and the culture layer 3; the surface layer of the culture layer 3 is a straw curtain , a composite layer of ginkgo leaves and medicinal residues; the wall 1 is provided with a wall-piercing pipe head 10 .

Agricultural waste is a mixture of one or more of farmland residues, orchard residues, agricultural by-product processing residues, and food manufacturing residues.

Farmland residues are straw and vegetable residues; orchard residues are rotten fruits, fruit shells, branches and fallen leaves of fruit trees; residues in agricultural and by-product processing industries and food manufacturing Debris, mushroom residue and sawdust.

When mixing sludge with agricultural waste, the carbon-to-nitrogen ratio (C/N) is controlled at 20:1~30:1, and the moisture content is controlled at 40%~60%.

The lowest layer of the anti-seepage layer is a compacted soil layer 4, and above the compacted soil layer is a modified bentonite layer 5.

The medicinal dregs are composed of hawthorn, scutellaria, brocade, malt and pulsatilla, with a weight ratio of 1:0.3~0.5:0.2~0.35:0.3~0.4:0.1~0.15.

The wall-piercing pipe head 10 is equipped with a plug 11 .

The collecting pool 8 is connected with the sewage treatment facilities.

After the sludge is transported to the factory area, it should be sent to the sludge storage area for storage. The storage area is built into a closed facility, and the ground is hardened and anti-seepage treatment. Sludge leachate drainage channels or devices are set up in the storage area to introduce the leachate into the sump, and no random discharge is allowed; an induced draft fan is installed in the storage area to send the gas in the storage area to the deodorization facility for treatment, and the deodorization facility adopts biological treatment and other low energy consumption processes. Storage facilities should be able to hold at least 7 days' worth of sludge. Earthworms are scavenging animals. At the same time, the sludge contains many toxic and harmful substances such as pathogenic microorganisms. In order to reduce the impact of sludge and other raw materials on earthworms, the raw materials must be pretreated. Pretreatment can be time-consuming such as aerobic static composting. Short, low-investment composting process. After aerobic composting of raw materials, when the temperature of the compost body reaches 55°C and lasts for 5 days, the requirements of raw material decomposing and harmlessness can be met. At this time, the composting process should be terminated to avoid loss of nutrients. After the preliminary decomposed raw materials are cooled, they can be used as earthworm food. Before the sludge is composted, straw and mushroom slag should be added to adjust the carbon-nitrogen ratio (C/N) and moisture content.

Earthworms feed on the food added to the breeding bed, and transform the sludge into vermicompost while multiplying themselves. Through proper harvesting of earthworms and vermicompost, two products of earthworms and vermicompost are obtained, which are processed. After that, takeaway sales. During the breeding process, the method of feeding from the upper part is adopted. After the added food is converted into vermicompost, it will not be harvested, and the food will continue to be added to the upper part until the bed height is about 1.0~1.5m. receive.

The terrain of the farm (factory) is often irregular. In order to facilitate the layout and management of the breeding bed area, it is advisable to divide the breeding area into several farming unit modules, and then arrange the breeding beds in the breeding area in a modular manner.

In the earthworm breeding area, the breeding modules should be arranged in a matrix. An artificial channel with a width of not less than 1m should be set between each row of breeding modules, and a walkway with a width of not less than 3m should be set between each row of breeding modules. ditch, and an earthworm breeding bed is arranged in the breeding module. A shelter is built around each culture unit module to keep out the rain and shade, and the gas circulation should be maintained.

After the construction of the breeding bed is completed, a layer of straw (corn, wheat, rapeseed, etc.) is laid on the bottom with a thickness of about 10cm, which acts as a gas guide, and 30cm of vermicompost is added on the upper part as a buffer layer for earthworms under unfavorable conditions. food layer; at the same time, when the height of the bed body reaches 80cm, when adding food materials, porous straw and other food materials should be added around the bed body. After the added food is converted into vermicompost, do not harvest it, and continue to add food to the upper part until the bed height is about 1.0~1.5m, then harvest the vermicompost, and keep the bottom 30cm after harvesting. layer of vermicompost.

The flavonoids in Ginkgo biloba have a good effect on improving the circulatory system and brain function of animals. As the covering component of the layer, in addition to helping to adjust the air and improve the soil, it can mainly improve the immunity of earthworms and increase its disease resistance. After comparison, it was found that the prevalence rate of earthworms was more than 5% higher in the planting beds without ginkgo leaves.

The dregs laid on the surface of the planting bed are composed of hawthorn, scutellaria, brocade, malt and pulsatilla. In addition to helping to adjust the air and improve the soil, all kinds of dregs can exert a certain medicinal effect, which is beneficial to the prevention of earthworms. Bacterial septicemia, bacterial gastrointestinal disease and other intestinal diseases have a synergistic effect, and the above-mentioned medicinal residues are easy to get, which also solves the waste pollution problem of pharmaceutical factories. After comparison, it was found that the disease rate of earthworms was 10% higher in the breeding beds without the above-mentioned medicinal residues.

Horizontal and/or vertical ventilation pipes are laid on the breeding bed, and a temperature regulating device is arranged in the ventilation pipes to increase the air permeability of the bed and adjust the moisture of the bed, which is beneficial to the growth and reproduction of earthworms.

With this kind of earthworm culture method, the higher bed body can increase the density of earthworms per unit area, increase the amount of sludge disposal, and save land resources; a certain thickness of earthworm manure layer can be used as a buffer zone for earthworms. , earthworms can escape to the layer, and there will be no phenomenon of earthworm escape; the upper part of the higher bed body will generally not be submerged by heavy rain, and at the same time, the ventilation layer set around the bed body, earthworms can use this area as a refuge buffer zone, so there will be no Due to poor ventilation, earthworms escape and die.

With this earthworm breeding method, the stocking density of earthworms is 0.5-1kg/m ² ; the food is added once every 15-20 days in winter and every 7-10 days in summer, and the thickness of the food added at one time is about 4-5cm. Earthworms can be harvested once every 60 days, and the harvesting density of earthworms is 2.5~3.5kg/m ² , and 1.0~1.5 tons of earthworms can be harvested per mu of land every year; months), 80-140 tons of vermicompost can be harvested per mu of land per year, and the vermicompost layer at the bottom 30 cm should be retained after harvesting. With this breeding method, 200-400 tons of sludge can be treated per mu of land per year.

Embodiment two

The method for the field breeding earthworm of this example to process sludge is except that the bottom layer of the anti-seepage layer is a compacted soil layer 4, and above the compacted soil layer is an anti-seepage film 5, and the anti-seepage film 5 is a geomembrane plus a geotextile, and all the others are the same Embodiment one.

Claims (8)

1. A method for earthworm breeding to treat sludge, which is to mix the sludge with agricultural waste, carry out fermentation pretreatment, lower the temperature, add it to the earthworm breeding bed, and control the pH value of the earthworm breeding bed as the breeding food for earthworms , temperature and humidity, the sludge is converted into vermicompost through feeding and digestion by earthworms, and two products of earthworms and vermicompost are obtained. ) has a top cover, and the vertical structure of the bed body in the wall (1) from the bottom to the upper part is an anti-seepage layer, an adjustment layer (2) and a breeding layer (3); the adjustment layer (2) is a pebble layer, The bottom of the pebble layer is provided with a perforated drainage pipe (6) and a perforated air distribution pipe (7). The perforated drainage pipe (6) is connected to the collection pool (8) outside the wall (1). (6) are connected; there is a geotextile (9) between the adjustment layer (2) and the culture layer (3); the surface layer of the culture layer (3) is a composite layer of straw curtains, ginkgo leaves and medicinal residues; the wall (1) A wall-piercing pipe head (10) is arranged on it. 2. The method for earthworm culture treatment sludge according to claim 1, characterized in that the agricultural waste is farmland residues, orchard residues, residues in the agricultural and sideline product processing industry and residues in the food manufacturing industry One or more of the mixture. 3. the method for earthworm culture treatment sludge according to claim 2, is characterized in that said farmland residue is the residue of stalks and vegetables; orchard residue is rotten fruit, fruit shell, branches and fallen leaves of fruit trees; Residues in the agricultural and sideline product processing industry and food manufacturing industry are vegetable residues, fruit residues, mushroom residues and sawdust. 4. The method for treating sludge by earthworm breeding according to claim 1, characterized in that the sludge is mixed with agricultural waste, the carbon-nitrogen ratio is controlled at 20:1~30:1, and the moisture content is controlled at 40 %~60%. 5. The method for treating sludge in earthworm breeding according to claim 1, characterized in that the lowest layer of the anti-seepage layer is a compacted soil layer (4), and above the compacted soil layer is a bentonite modified layer or anti-seepage Membrane (5). 6. The method for treating sludge by earthworm breeding according to claim 1, characterized in that the dregs are composed of hawthorn, scutellaria baicalensis, brocade, malt and Pulsatilla pulsatilla, and the weight ratio is 1:0.3~0.5:0.2~ 0.35: 0.3~0.4: 0.1~0.15. 7. The method for treating sludge in earthworm breeding according to claim 1, characterized in that the wall-piercing pipe head (10) is equipped with a plug (11). 8. The method for treating sludge in earthworm breeding according to claim 1, characterized in that the collection pool (8) is connected to a sewage treatment facility.