Earthworms, commonly known as earthworms, also known as Eel, are the representative animals of Oligochaeta in annelida. Earthworms are saprophytic living animals. They live in humid environment and feed on corrupt organic matter. They are full of a large number of microorganisms but seldom get sick. This is related to the unique number of antimicrobial immune systems in these earthworms.
In scientific classification, they belong to unidirectional earthworms. The body is cylindrical (distinct from the cylindrical shape of linear animals), symmetrical on both sides and segmented: it consists of more than 100 segments. After the Eleventh segment, there is a dorsal foramen in the middle of the back of each segment; there is no skeleton, it belongs to invertebrates, with bare body surface and no cuticle. Except for the first two segments of the body, all the other segments have bristles. Hermaphroditism, allogeneic fertilization, reproduction by the ring to produce cocoons, reproduction of the next generation. There are more than 2500 known earthworms. Darwin pointed out in 1881 that earthworms are the most important animal group in the world’s evolutionary history.
Body wall and secondary body cavity
The body wall of earthworms consists of cuticle, epithelium, circular muscular layer, longitudinal muscular layer and coelomic epithelium. The outermost layer is a single layer of columnar epithelial cells whose secretions form cuticle. The membrane is very thin, consisting of collagen fibers and non-fibrous layers with small holes. Cylindrical epithelial cells were mixed with fine glands cells, divided into mucous cells and protein cells, can secrete mucus and make the body surface moist. Earthworms encounter intense stimulation. Mucous cells secrete a large amount of mucus to wrap the body into a mucous membrane, which has a protective effect. Epithelial cells have short basal cells at the base, and some people think that they can develop into columnar epithelial cells. Sensory cells aggregate to form sensory organs and disperse between epithelial cells. The nerve fibers of a thin layer of nerve tissue under the epithelium are connected at the base. In addition, there are photoreceptor cells, the base of epithelium, also connected with the nerve fibers below it.
The muscles of earthworms belong to the twill muscles, which generally account for about 40% of the body volume. They are well-developed and flexible. When the longitudinal muscular layer of some segments of the earthworm contracts and the circular muscular layer relaxes, the segment becomes thicker and shorter, and the retracted bristles born on the body wall obliquely extend into the surrounding soil; at this time, the circular muscular layer of the former segment contracts, the longitudinal muscular layer relaxes, the segment becomes thinner and longer, and the bristles retract, thus breaking away from the surrounding soil. The bristle support of the latter segment pushes the body forward. In this way, the contraction wave of muscles gradually passes forward and backward along the longitudinal axis of the body.
The coelomic compartment is separated by the septum according to the body segment, and each compartment is connected with a small hole. Each body chamber is formed by the development of left and right two body sacs. The medial part of the sac formed visceral membranes, while the dorsal and ventral parts formed dorsal and peritoneal mesenteries. In earthworms, the mesentery of the abdomen degenerates, only part between the intestine and the abdominal vessels exists, while the mesentery of the back disappears. The part between the anterior and posterior coelomic sacs is closely together, forming a septum. Some species have no septum in the esophagus.
The digestive tract runs longitudinally in the central part of the body cavity and passes through the septum. The muscular layer of the wall of the digestive tract is well developed, which can improve peristalsis and digestive function. The digestive tract is differentiated into mouth, mouth, throat, esophagus, sand sac, stomach, intestine and anus. The mouth can be turned out from the mouth to ingest food. The pharyngeal muscles are well developed, the muscles contract, and the pharyngeal cavity enlarges to support feeding. There is a single-cell pharyngeal gland outside the pharynx, which secretes mucus and proteinase, moisturizes food and has a preliminary digestive effect. After pharynx, there is a short and thin esophagus with esophageal glands on its wall. It can secrete calcium and neutralize acidic substances. The back of the esophagus is a muscular sand sac (gizzard), lined with a thick cutin membrane, which can grind food. From mouth to sand sac, the ectoderm is formed and belongs to foregut. The digestive tract behind the sand sac is rich in microvessels and glands, which is called stomach. There is a circle of gastric glands in front of the stomach, which functions like pharyngeal glands. The digestive tract enlarges to form the intestine, and its dorsal central fovea enters into a blind canal (typhlosole), which enlarges the area of digestion and absorption. Digestion and absorption are mainly performed in the intestine. The outermost visceral membranes of the intestinal wall specialize into yellow cells. Since the 26th body segment, a pair of conical cecum (caeca) extending forward from both sides of the intestine can secrete a variety of enzymes, which are important digestive glands. The stomach and intestine originate from the endoderm and belong to the midgut. The posterior intestine is relatively short, accounting for about 20 body segments in the posterior end of the digestive tract. It has no blind passage and no digestive function. Open to the body through the anus. The digestive system of earthworms consists of more developed digestive ducts and glands. The digestive ducts are composed of oral cavity, pharynx, esophagus, crop sac, sand sac, stomach, small intestine, cecum, rectum and anus.
Earthworms are very special. Like their body segments without obvious merger, their hearts are also divided into several segments in the front of the body, generally 4-5, which are circular, like enlarged blood vessels, so they are also called circular blood vessels. The dorsal side of the annular heart is connected with the dorsal blood vessel from the back to the front, and the ventral side is connected with the abdominal blood vessel from the front to the back. The abdominal blood vessel and its branches are connected with the inferior nerve blood vessel from the front to the back. The annular heart has thicker muscular walls than blood vessels and pulsates. There are also valves that open unilaterally to ensure blood flow from the dorsal to the abdominal vessels. Generally speaking, the blood flow is powered by the pulsation of these independent annular hearts. The direction of blood flow is from back to front (in the dorsal vessels), from back to abdomen (in the annular heart), and from front to back (abdominal vessels and subnervous vessels).
Respiration and Excretion
The excretory organs of earthworms are posterior renal tubules. In general, each segment has a pair of typical posterior renal tubules.
Bio Engine Composting Part 2
Classification by type of fermentation plant
According to the type of fermentation device, there are vertical composting fermentation tower, horizontal composting fermentation drum, silo composting fermentation tank and box composting fermentation tank.
1 vertical compost fermentation tower
Vertical composting fermentation tower usually consists of 5-8 layers. The composting material enters the tower from the top of the tower. In the tower, composting moves from the top of the tower to the bottom of the tower through different forms of mechanical movement. Generally, after 5 to 8 days of aerobic fermentation, the compost is moved from the top of the tower to the bottom of the tower to complete a fermentation. Vertical composting fermentation tower usually has a closed structure. The temperature distribution in the tower gradually increases from the upper layer to the lower layer, that is, the lowest layer has the highest temperature. In order to ensure the activity of microorganisms in each layer for high-speed composting and maintain the optimum temperature and ventilation volume of microorganisms in each layer of the tower respectively, the oxygen supply of the tower device is usually forced ventilated by a fan, and the air is quantitatively ventilated into the tower through the vents of different heights installed on the side of the tower body to meet the micro-generation. The demand for oxygen.
Vertical composting fermentation tower usually includes vertical multi-stage cylinder type, vertical multi-stage landing gate type, vertical multi-stage blade scraper type, vertical multi-stage movable bed type, etc.
2 horizontal composting fermentation drums
Horizontal composting fermentation drum is also called Danot type. The main equipment is a horizontal drum with a length of 20-35 m and a diameter of 2-3.5 M. In the fermentation device, waste is raised along the rotating direction by friction with the inner surface of the cylinder, and falls down by means of self-weight. By rising and falling repeatedly, the waste is evenly turned over and contacted with the air supplied, and fermented by microorganisms. In addition, because the cylinder is oblique, when the waste lifted along the rotating direction falls by its own weight, it gradually moves to one end of the outlet of the cylinder, so that the rotary kiln can automatically and steadily supply, transport and discharge compost. The processing conditions of the device are summarized as follows:
The ventilated air temperature is normal in principle. For a 24-hour continuous operation device, the ventilation rate is 0.1 m3/(m3.mm), and the rotating speed of stirring in the cylinder should be 0.2-3.0 r/min. If the whole fermentation process is completed in this device, the residence time should be 2-5 days. The filling rate of cylinder is generally as follows: waste volume in cylinder/cylinder capacity is less than capacity. The average temperature of compost in the whole fermentation process is 50-60 when the device is used, and the maximum temperature can reach 70-80 high. When the device is used for one fermentation, the average temperature is 35-45, and the maximum temperature can be about 60 high.
3 silo type compost fermentation silo
Silo-type compost fermentation silo is a single-layer cylindrical (or rectangular) fermentation silo, the depth of fermentation silo is generally 4-5 M. The upper part is provided with a feed inlet and a scraper diversion device, and the lower part is provided with a screw discharger. Most of them are made of reinforced concrete. High-pressure centrifugal fan was used to supply oxygen in fermentation chamber to maintain aerobic fermentation of compost in fermentation chamber. Air generally enters the fermentation bin from the bottom of the silo, and composting material enters from the top of the silo. After 6-12 days of aerobic fermentation, the compost with initial maturity was discharged from the bottom of the silo through the discharger. According to the movement form of compost in fermentation bin, silo fermentation bin can be divided into static and dynamic.
(1) Silo-type static fermentation bin.
The device is a single-layer cylinder with stacking height of 4-5 M. The compost enters the silo through the distributor from the top of the silo. After 10-12 days of aerobic fermentation, the compost is discharged by the screw discharger at the bottom of the silo. Because there is no repetitive cutting device in the warehouse, the raw materials are compacted and lumpy, the ventilation performance is poor, the ventilation resistance is large, the power consumption is large, and the product is difficult to homogenize. However, the device occupies a small area and has a high utilization rate of fermentation bin, which is its advantage. The structure of this device is simple, so it is widely used.
(2) Silo-type dynamic fermentation silo.
The silo-type dynamic fermentation silo is a single-layer cylindrical silo with a stacking height of 1.5-2 M. During the operation of the dynamic fermentation bin, the crushed wastes sorted by the pretreatment process are transferred to the middle of the top of the tank by the feeder, and then uniformly distributed by the feeder to the tank. The screw drill located in the rotating layer stirs the wastes in the tank by revolution and rotation, so as to prevent the formation of grooves, and the shape and arrangement of the screw drills can pass through. Maintain a uniform distribution of air. Waste falls from the top down in the pond by gravity. Rotary cutting screw device with revolution and rotation is installed at the bottom of the pool. Whether the upper rotating layer rotates or not, the product can be discharged from the bottom of the pool. The air required for aerobic fermentation is forced into the bottom of the pond through the air distribution board. In order to maintain the aerobic environment in the pond and promote fermentation, forced ventilation from the bottom of the pond was adopted by blower. By measuring the temperature and gas concentration in each section of the pool, the air quantity supplied to each section can be adjusted and the rotation period of the bridge tower can be controlled to change the overturning frequency. The period of one fermentation is 5-7 days. In the composting process, the helical blades cut off the raw materials repeatedly, and the raw materials are pressed on the helical surface, which is easy to produce compacted lumps, so the ventilation performance is not very good. In addition, it also has some shortcomings, such as uneven residence time of raw materials, uneven product shape and not easy to seal. Its advantage is that the height of the outlet and the residence time of the raw material can be adjusted.
4 Box composting fermentation tank
There are many kinds of box-type composting fermentation ponds and their applications are very common. The main classifications of box-type composting fermentation ponds are as follows:
(1) Rectangular fixed plough-shaped overturned fermentation tank.
The box-type composting fermentation pool is equipped with plough-type upside-down mixing device. The device acts as a mechanical plough to dig waste. It can regularly agitate and move materials several times. It can keep the ventilation in the pool, make the materials evenly disperse, and also has transportation function. It can move materials from the feed end to the discharge end, and the materials stay in the pool for 5-10 days. The air is forced to ventilate through the air distributor at the bottom of the pool. Fermentation tank adopts conveying mixing device, which can increase the height of material accumulation.
(2) Fan bucket overturned fermentation tank.
This kind of fermentation tank is horizontally fixed. It is equipped with a dumper to mix the waste so that the humidity of the waste is uniform and in contact with the air, which promotes the rapid decomposition of compost and prevents the generation of odor. The residence time is 7 to 10 days. The frequency of dumping waste is once a day as the standard. The number of dumping can also be changed depending on the material properties. The fermentation plant has several characteristics in operation: the fermentation tank is equipped with a mixer and an overturning car mounted on the truck conveyor. When the waste is overturned, the overturning car runs on the fermentation tank. When the overturning operation is completed, the overturning car returns to the movable car. According to the handling capacity, sometimes the traveling crane structure can not be installed. Vehicle conveyor; When the material in the pond is overturned, the mixer is lifted by rope traction or mechanical piston tilting device, and when it is overturned again, the mixer can be put down to start mixing; In order to transfer the overturning vehicle from one fermentation pond to another fermentation pond, the track conveyor and crane can be used to scrape out the conveyor and belt conveyor. Feeder or swing conveyor, compost is agitated by mixer, conveyed by vehicle conveyor at the end of fermentation pool, and finally scraped out of the pool by scraper conveyor placed on movable car. Several specific stages of fermentation process are controlled by a compressor, and the required air is blown in from the bottom of fermentation pool.
(3) Crane overturned fermentation tank.
This kind of fermentation tank is usually used for secondary fermentation. The compostable materials which have been crushed and sorted by the pretreatment equipment or which have been fermented once are sent to the fermentation tank by the conveying equipment, and the compostable materials which are fed into the fermentation tank are piled up in the designated box fermentation tank by the shuttle conveying equipment. During accumulation, air is supplied from suction trough, and hopper crane is used to overturn material and perform vaccination operation at the same time.
(4) Horizontal blade fermentation tank
The agitator blade is attached to the mobile device and then moves. Because the mixing device can move horizontally and vertically, the mixing device moves the mixing material repeatedly vertically and transversely at the same time. Because stirring can be used throughout the fermentation tank, the fermentation tank can be designed very wide, so that the fermentation tank has greater processing capacity.
(5) Horizontal scraper fermentation tank.
The main component of the fermentation tank is a flaky scraper driven by gear and rack. The scraper swings from left to right to stir waste, returns from right to left without load, and then swings from left to right to push a certain amount of material. The amount of material pushed by the scraper can be adjusted. For example, when stirring once a day, adjustable push volume is required for a day. If the treatment capacity is large, the fermentation tank can be designed into a multi-stage structure. The pool body is a sealed negative pressure structure, so the odor does not escape. The fermentation tank has many ventilation holes to maintain aerobic condition. In addition, sprinkler and drainage facilities are installed to regulate humidity.
The type of composting equipment used and the corresponding composting process usually depend on the following factors:
- Types of solid waste;
- Establishing natural conditions of composting plant site (distance from residential area, topography, wind direction, etc.);
- Control level of secondary pollutants (leachate, odor gas) in composting process;
Investment and operation cost of plant construction.
Because of the superiority of geographical location, stacking composting can be widely used in rural areas and small towns. However, in some densely populated rural areas, farms, aquaculture farms, urban suburbs and other areas, the composting process with high efficiency for odor gas and leachate treatment should be chosen first.
Trend of development
The Seattle Solid Waste Utilities Bureau first implemented the Masterminer Program in the United States in 1986, marking the beginning of household composting, which mainly uses composting technology to treat yard waste and food waste. In 1995, 41% of Seattle households implemented household composting, diverting about 8 300 tons of yard waste, 82% of which was used for yard greening. There are studies. In the Mississauga area of Ontario, roadside collection, centralized composting and household composting cost $140 t-1, $190 T-1 and $50 t-1, respectively. Moreover, household composting can reduce the amount of household garbage by 3%-5%. Compared with centralized and large-scale composting systems, household composting has significant advantages: low cost and reduction of solid waste sources. In Seattle, there are two types of household composters for food waste: earthworm boxes and conical buckets. In the past, earthworm boxes were commonly used. Now, conical barrels are popular. The height of conical barrels is about 0.9 M. There is a basket with a height of 0.46 M. It can accommodate food waste produced by a family of three within 6 to 9 months. There are two kinds of household composters for yard waste: 0.34 m3 and 0.59 m3. Wood, recycled polyethylene and stainless steel are used to make household composters.
Composting toilets are suitable for places without or without water, such as large-scale composting toilets for parks, highways, stations, etc., and small-scale composting toilets for ships, etc. The commercial composting toilets are divided into self-contained and centralized ones, which can be operated intermittently or continuously, and are made of glass fibre and polyethylene. The self-contained composter is located next to the toilet, while the centralized composter is located next to the basement or building. Intermittent composting toilets contain more than one compartment. When one compartment is full, they are transferred to another compartment. Its advantage is that there is only one compartment in the composting toilet which can run continuously without contamination by fresh manure. Fresh manure and decomposed quasi-manure are mixed together.
Small Capacity Reactor Suitable for Field Operation
Because of the economic, odor control and site reasons, composting systems with large reactors, forced ventilation static stacking and strip stacking are greatly limited. Therefore, a portable, small-capacity reactor composting system suitable for field operation emerges as the times require. For example, Mulch Co. of County, UK, has built two mobile composting systems (30.584-38.23 m3 in volume) similar to rolling containers, with bucket loaders for feeding and cranes for lifting containers when discharging, and materials poured out from the back door of containers. Temperature and oxygen content are controlled by computer. Although this kind of system has only appeared for a few years, it is receiving more and more attention and application from small sewage treatment plants, food industry, catering industry, communities, schools, hospitals, research institutes and business groups. At present, it is mainly used for food waste treatment. The small capacity reactor composting system on the market includes box system, mixing bin and rotary digester, etc. But at present, the most commonly used one is box composting system. The system can be operated intermittently or continuously. It has the advantages of good process control, low investment and operation cost, simple equipment, easy operation and assembly, etc. But its greatest advantage is that it is easy to operate and assemble. Organic waste treatment technology is provided for groups or units that do not have enough space. Currently, 50 and 25 box composting systems are operating in the United States and Canada, respectively. A typical box-type composting system has a treatment scale of 1-40 t/d-1. It consists of several boxes, two of which are used as biofilters. In order to facilitate field operation, the mixing equipment and reactor are connected with the trailer.
In a word, the source of solid waste is more and more dispersed, and the amount of solid waste is also more and more, so the application scope of composting equipment will gradually expand. For different solid wastes, different composting equipments need to be adopted and developed. With the development of solid waste composting, household composters and small-capacity reactor composting systems emerge as the times require. On the one hand, home composters have been reduced from the source.
Ways to Make Composts
How to Compost
The Method of Making Compost Fertilizer from Straw
- Method of composting:
- Site selection Fertilizer-making site should be located in the leeward sunward area with flat terrain and close to the water source, which can be made in the open air all the year round. A kind of
- Material preparation (Take 1 ton of dry straw as an example)
(1) 1000 kg of crop straw.
(2) 20 kg corn flour or wheat bran or rice bran, and 5-10 kg urea can be added if conditions permit.
(3) Bacillus Yikang compost fermentation strain 400g (two bags of this product).
(1) The length of straw (e.g. corn straw) should be 1-3 centimeters when it is crushed or cut by a hay cutter (wheat straw, rice straw, leaves, weeds, peanut seedlings, bean straw, etc.) can be fermented directly, but the fermentation effect is better after crushing.
(2) Water the crushed or cut straw with water to wet and permeate, and the moisture content of straw is generally controlled at about 60%.
(3) Mix 20 kilograms of corn flour (or wheat bran or rice bran) with 400 grams of bacteria. Sprinkle corn flour (or wheat bran or rice bran) mixed with bacteria evenly on the surface of straw irrigated with water by hand. Use spade and other tools to turn over and mix, stack into long strips of 2 meters wide, 1.5 meters high and unlimited length, and cover them tightly with plastic cloth.
(1) Warming up stage: from room temperature to 45 C, generally only one day, at this time can turn over the stack.
(2) In the future, when the heap temperature reaches above 60 C, it needs to be turned over, and the basic state of decomposition can be reached in 15-20 days, and the fertilizer can be applied directly. Maturity mark straw turns brown or black-brown, soft and elastic when wet, brittle and fragile when dry.
(1) Straw fertilizer is generally used as base fertilizer and can be applied wetly. Soil should be covered for topdressing. Semi-decomposed fertilizer is applied to crops with longer growth period, straw fertilizer with higher maturity is applied to crops such as melons, fruits and vegetables with shorter growth period, semi-decomposed fertilizer is used in sandy soil, and fertilizer with higher maturity is best applied to clay soil.
(2) Straw fertilizer is rich in organic matter, balanced nutrients of nitrogen, phosphorus and potassium, and contains various trace elements. It is a suitable fertilizer for all kinds of crops and soils. It has remarkable effects on improving crop quality and increasing yield. A kind of
Note: It is suggested that 20-30% livestock and poultry manure or other organic substances should be properly added in composting, so that the fertilizer efficiency is better and more comprehensive.
（3）Rapid Fermentation of Straw Returning to Field:
Quick Returning Technology: Digging Trough – Stacking Straw – Adding Bacteria and Yikang – Sealing
1) Digging trough: Digging a low trough 1.5-2 m wide and 0.3 m deep in idle fields such as fields and courtyards, the length of which can be determined according to the amount of straw. _
2) Stacking straw: According to the standard of 60% moisture content of straw (i.e. holding the water in groups and keeping the watermarking by hand without dripping, it is appropriate to lay down and disperse), so that the straw can absorb enough moisture and accumulate straw in the tank.
3) Adding organic fertilizer starter: first, add 1 bag (200g) of Bacteria Yikang to dilute 20 kg corn flour or rice bran or wheat bran (1000 kg straw material), then stack straw while adding animal manure or urea to adjust C/N ratio and evenly sprinkle corn flour with Bacteria Yikang. Or rice bran or wheat bran.
4) Sealing: When the pile is about 1:5 meters high, photograph it and seal it with clay or plastic film. About 15 days in summer and 40 days in winter can be fertilized and returned to the field.
Quick in-situ Returning Technology of Straw Returning to the Field: Straw Crushing-Adding Bacteria Yikang and Feces-Sealing-Tillage-Tillage
1) Straw crushing: The straw is crushed into small segments of about 3-4 cm with a crusher.
2) Add Bacteria Yikang: first, add 2 bags of Bacteria Yikang (400 grams) into 40 kg corn flour or rice bran, wheat bran dilution; decomposed feces and urine 300 kg; all kinds of straw 700 kg. Mix the above materials well, then add water, adjust the moisture content of straw to about 60%, accumulate in the earth and compact slightly. A kind of
3) Sealing: After accumulating the material, the material is sealed with mud. A kind of
4) Tillage: Sprinkle the rotten straw evenly on the ground, and immediately carry out deep tillage, raking and further maturation of the straw.
Rapid Decomposition and Return of Rice Straw to Field Technology Harvesting Fertilizing Adding Green Seedlings to Strengthen Throwing Seedlings
1) Harvesting: one is to keep high stubble harvested, tail grass left in the field, 100% straw returned to the field; the other is low stubble harvested, after threshing also returned to the field in full.
2) Fertilization: Planned application of organic and inorganic fertilizers in the field.
3) Bacterial Yikang: According to 1000 kg of straw, add 500 grams of Bacterial Yikang, evenly sprinkle in the field. When applied, the water layer in the field was 2-3 cm.
4) Seedling throwing: After applying Bacillus Yikang, the farmland can be thrown for one day. When throwing rice seedlings, the surface of the field should maintain a certain water layer. The water layer of the high stubble paddy field and straw strip mulch is shallow, 2-3 cm. The paddy field covered with straw is deep, about 5 cm. Submerged straw is the standard to ensure the contact between seedling roots and water.
Technical Operating Points
1) Adequate moisture: straw must absorb enough water, the moisture content is generally controlled at about 60%. A kind of
2) Adjust the appropriate C/N: Add appropriate amount of animal manure or nitrogen fertilizer to regulate the C/N of the compost.
3) Blend material: Bacteria Yikang added should be evenly sprinkled in straw, or stirred evenly with utensils.
4) Ventilation: Microorganisms ferment faster under aerobic conditions, and the condition of ventilation will directly affect the stalk maturation rate. So don’t step on it when stacking, in order to facilitate ventilation. After stacking, it is sealed with mud mixed with straw. When the temperature in the stack exceeds 65 degrees, ventilation or dump should be adopted.
5) Sealing: When stacking, the surrounding and top of the reactor should be sealed to prevent water evaporation and nutrient loss.
6) Warming up: When composting straw in winter or cold area, plastic film is added to the compost to increase the temperature. Fourth, attention should be paid to the sufficient moisture content of materials for stacking and composting, the uniform mixing, sealing, heat preservation and water retention, so as to ensure that straw is quickly matured and accumulated without stepping on it, and take a slight photo.
Last, the suitable area, all kinds of straw crops can be treated by straw composting and returning technology after harvesting.