Taking the water system as a whole, according to the geographical distribution of towns and industrial and mining enterprises along the coast of the water system, as well as the self-purification capacity, pollution capacity and pollution status of the water system, comprehensive prevention and control measures are taken to prevent and control water pollution. It includes various engineering technology means and management measures, which have the characteristics of integrity, comprehensiveness and regionality.
Comprehensive prevention and control of water pollution is a comprehensive application of various measures to prevent and control water pollution. Prevention and control measures involve two types of engineering and non-engineering, mainly:
(1) Reducing the discharge of wastewater and pollutants, including saving production wastewater, stipulating water quota, improving production technology and management system, increasing the reuse rate of wastewater, adopting new technology without pollution or less pollution, and formulating material quota, etc. For water-deficient cities and industrial and mining areas, regional recycling water and wastewater reuse systems should be developed.
(2) Developing regional water pollution prevention and control systems, including formulating urban water pollution prevention and control plans, river basin water pollution prevention and control management plans, implementing the total amount control system of water pollutant discharge, developing sewage after proper manual treatment for irrigation farmland and reuse for industry, establishing sewage reservoirs without polluting groundwater, and low water. Periodic storage of sewage reduces sewage discharge load and conducts controlled dilution during flood period.
(3) Develop wastewater treatment technologies with high efficiency and low energy consumption to treat wastewater.
Comprehensive prevention and control of pollution refers to the comprehensive use of various measures to prevent and control water environmental pollution from the whole point of view. It is very necessary to implement comprehensive prevention and control of water pollution, because China is a country with relatively scarce water resources, and there are two manifestations: one is resource-based water shortage, the other is water-quality-based water shortage. For a long time, the purification treatment of sewage outlet based on point source control can not effectively solve the problem of water pollution. Comprehensive prevention and control of water pollution must be carried out from the overall point of view of the region and water system in order to fundamentally control water pollution and solve the problem of water shortage caused by water quality.
Why do this
The necessity and urgency of comprehensive prevention and control of water pollution are embodied in two aspects: first, the contradiction between water resources shortage and unbalanced supply and demand is prominent, and the serious pollution of water environment makes this contradiction more prominent and urgently needs to be solved;
Why is it so urgent?
Secondly, the purification treatment of sewage outlets based on point source control can not effectively solve the problem of water pollution. Comprehensive prevention and control of water pollution must be carried out from the whole region or water system, and the tail control of point source control should be transferred to the source control in order to control water pollution fundamentally.
The basic principle of sewage prevention and control is the combination of prevention, treatment and management.
Through effective control and preventive measures, the amount of pollutants discharged by pollution sources can be reduced to the minimum.
(1) For industrial pollution sources, the most effective control method is to promote cleaner production. Cleaner production refers to the advanced production technology with the smallest utilization of resources and energy and the least pollution emission. The main technical routes adopted in cleaner production include: reforming raw material selection and product design, replacing toxic and harmful raw materials and products with non-toxic and harmless raw materials and products; reforming production process to reduce consumption of raw materials, water and energy; adopting recycling water system to reduce wastewater discharge; and recycling the usefulness of wastewater. Composition, reduce the concentration of wastewater, etc. Cleaner production advocates life cycle analysis and management of products rather than end-treatment.
(2) For domestic pollution sources, effective measures can be taken to reduce their emissions. Such as promoting the use of water-saving appliances, improving people’s awareness of water-saving, reducing water consumption, thereby reducing domestic sewage discharge.
(3) For agricultural pollution sources, in order to effectively control non-point pollution sources, we must start from “prevention”. Promoting scientific fertilization and rational use of pesticides in farmland can greatly reduce the residual fertilizers and pesticides in farmland, thereby reducing the amount of nitrogen, phosphorus and pesticides contained in farmland runoff.
Through various measures to control pollution sources and polluted water bodies, the pollution sources can achieve “standard discharge” and the water environment can achieve the corresponding water quality function.
It is very difficult or almost impossible for pollution sources to achieve zero discharge. Therefore, it is necessary to properly treat polluted (waste) water to ensure that the discharge standards set by the state or local authorities are met before it is discharged into the water body. Great attention should be paid to the relationship between industrial wastewater treatment and municipal wastewater treatment. For industrial wastewater containing acid, alkali, toxic and harmful substances, heavy metals or other special pollutants, local treatment should be carried out in the plant to meet the discharge standards to the water body or the water quality standards to the urban sewer. Those industrial wastewater similar in nature to municipal domestic sewage can be treated together with municipal sewage as a priority. It is not only unnecessary but also uneconomical to set up sewage treatment facilities separately. The design of urban sewage collection system and treatment plant should not only consider the need of water pollution prevention, but also the need to alleviate the contradiction of water resources. In areas where water resources are scarce, the treated municipal wastewater can be reused for agriculture, industry or municipal administration and become stable water resources. In order to meet the needs of wastewater reuse, its collection system and treatment plant should not be too centralized, but should be close to the reuse target.
In addition, according to the characteristics of water pollution, we should actively take physical, chemical, biological engineering and other means to control pollution, so that the deteriorated aquatic ecosystem can be gradually restored.
Strengthen the supervision and management of pollution sources, water bodies and water treatment facilities in order to promote treatment. Pipe also plays an important role in water pollution control. Scientific management includes regular monitoring and inspection of pollution sources, water treatment facilities and sewage treatment plants, and regular monitoring of water environmental quality to provide basis and information for environmental management.
Functional zoning of water environment is the basis for comprehensive prevention and control of water pollution
According to the current functions of water environment and the needs of economic and social development, the functional zoning of water environment is based on surface water environmental quality standards, which is the basis of water source protection and water pollution control. For example, the surface water environmental quality standard divides the water area control functions into five categories: Class I is mainly applicable to source water and national nature reserves; Class II is mainly applicable to primary protection areas of centralized drinking water sources, precious fish protection areas, fish and shrimp spawning grounds; Class III is mainly applicable to centralized drinking water sources II. Class IV is mainly suitable for general industrial water use and recreational water areas where human body does not contact directly; Class V is mainly suitable for agricultural water use areas and waters where general landscape requires.
Principles and methods
The principles of division are as follows: priority protection of centralized drinking water source areas; water body should not reduce its current use function, taking into account planning function; water areas with multiple functions should be classified according to the highest function; professional water standard requirements should be considered as a whole; consideration should be given to each other between upstream and downstream areas, with due consideration to potential functional requirements; and rational use of water body itself. Net capacity and environmental capacity; Consider the combination of land industrial rational layout; Consider the impact on underground drinking water sources; Practical and feasible, easy to manage.
Functional zoning method: according to the principle of adapting measures to local conditions and seeking truth from facts, according to actual measurement, empirical analysis and administrative decision-making.
Controlling pollution and protecting water sources according to functional areas.
(i) The level of protection shall be defined according to the functions of the waters and the requirements for water pollution control shall be put forward. For example, special protected waters refer to the first and second categories of national Surface Water Environmental Quality Standards (GB3838-2002). No new sewage outlets shall be built for such waters. Existing sewage discharge units shall be strictly controlled by local environmental departments in order to ensure that the water quality of accepted waters meets the water quality standards for specified purposes; and key protected waters shall be protected. It refers to the third class waters stipulated by GB3838-2002, and the first class discharge standards stipulated in the Comprehensive Sewage Discharge Standard (GB8978-1996) are applied to the sewage discharged into the waters.
(ii) The total amount control shall be implemented according to the functional areas. The so-called total amount control refers to the maximum allowable emission of some kind of pollution in order to maintain the environmental target value of an environmental functional area. Therefore, water environmental functional zoning is the basis for implementing total water pollution control.
Formulating comprehensive prevention and control plan of water pollution
Main contents and working steps
(i) Based on the investigation and evaluation of water environment, the main problems of water environment are analyzed and determined.
(ii) Division of water pollution control units. According to the analysis conclusion of water environment problems, considering the administrative division, water area characteristics and pollution source distribution characteristics, the source area and receiving water area are divided into water pollution control units.
(iii) Put forward environmental objectives and demonstrate accessibility. At the Fourth Session of the National People’s Congress, the strategic goal of environmental protection across the century was clearly put forward, which is the basis for the goal of comprehensive prevention and control of water pollution. Environmental objectives should include the total amount control objectives of major pollutants and the specific objectives of various sub-items of comprehensive water environment improvement. It is necessary to demonstrate the accessibility of environmental objectives.
(iv) Determine the amount of major pollutant reduction and the proportion of reduction allocation.
(v) To formulate a comprehensive water pollution prevention and control plan and implementation plan.
(vi) Support and guarantee for the implementation of the plan. Including: analysis of sources of funds, formulation of annual plans, implementation of pollutant discharge declaration and registration and pollutant discharge permit system proposals, as well as the necessary technical support.
Several principles that must be adhered to in formulating comprehensive water pollution prevention and control plan
(i) Focusing on economic construction is conducive to the coordinated development of economy and environment.
(ii) Take rational development and utilization of water resources as the core, focusing on the whole process control. By changing the mode of economic growth and promoting cleaner production, pollution can be eliminated in the process of economic reproduction.
(iii) Overall planning, highlighting key points, adapting measures to local conditions and stressing practical results.
(iv) adhering to the principle of comprehensive improvement. Systematic analysis of the planning scheme is needed to achieve overall optimization.
Emission permit system, transition from concentration control to total quantity control
Practice has proved that in carrying out this system, we must follow the following five requirements in the light of China’s current technological level and management system.
(1) Determine the total amount control target from the actual point of view. When it is difficult to determine the environmental capacity of the receiving water body for discharging pollutants, according to the principle of the total amount control plan put forward by the State Environmental Protection Administration in December 1995, the total amount of discharged major water pollutants in 1995 can be regarded as the target total amount, and the proportion of reduction can be determined according to the actual technical and economic level of the region, and allocated to the main body. Pollution sources.
(2) Choose the target of issuing certificates. The main target of issuing permits is the large polluters in the region. A city can catch more than a dozen or dozens of households. It is necessary to select the key control points through investigation and evaluation of pollution sources. For example, Anyang City put forward that we should do a good job of 2, 5 and 8, and control 8 and 9, that is, we should catch 20, 50 and 80 large polluters in batches, and control 70%, 80% and 90% of the city’s water pollution load.
- Control the total amount of sewage. Measure according to local conditions and control the total amount of sewage.
- Strengthen environmental supervision and management after issuance of certificates.
- Pay attention to practical experience and constantly improve the level. In order to implement the sewage discharge permit system, we should first carry out pilot projects, sum up experience and gradually popularize it.
- But we should also pay attention to the new problems in the process of implementation, such as the paid transfer of pollutant discharge indicators and the trading of pollutant discharge rights.
- Comprehensive Prevention and Control of Water Pollution in Township Enterprises
- The discharge of industrial wastewater from township enterprises was only 3.9 billion tons in 1997.
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.
Biotechnology is a well-known term. The National Science and Technology Commission defines biotechnology as “biotechnology contains a series of technologies that can produce the products we need from organisms or cells, including gene recombination, cell fusion and some biological manufacturing processes.”
In fact, human beings have a long history of using organisms or cells to produce the products we need, such as tillage 10,000 years ago, animal husbandry to provide a stable source of food, fermentation technology to brew wine and make bread 6,000 years ago, fungus to treat wounds 2,000 years ago, and use in 1797. Smallpox vaccine, the discovery of antibiotic penicillin in 1928, etc.
Since human beings have been using biotechnology for so long, why has biotechnology suddenly attracted widespread attention since 1990? This is because since the 1950s, the scientific community has had a better understanding of the cells that constitute the smallest unit of organisms and the genes that control the genetic characteristics of cells, as well as the development of gene recombination and cell fusion techniques in the 1970s. Since these two technologies can enable cells or organisms to produce the substances we need more effectively, and contribute to industrial or agricultural production, a new biotechnology industry has been created since the 1980s.
Bill Gates said in 1996 that “biotechnology will change the world like computer software”. Modern biotechnology industry has been developing since 1980, and its applications include pharmaceuticals, agriculture, environmental protection, food processing, special chemicals and other industries. In the field of biomedical pharmaceuticals, 155 biotechnology drugs or vaccines have been approved by the Food and Drug Administration of the United States and used to treat diabetes, heart disease, cancer, AIDS and other diseases. In agriculture, genetic recombinant plants such as papaya, tomato, maize and soybean have been listed. These plants are characterized by strong resistance to pests and diseases, and can reduce the use of chemical pesticides.
The progress of human civilization is from the collecting society of early fishery hunting life to the agricultural society dominated by farming and animal husbandry, and then to the modern industrial society. Because of the increasing population and the over-exploitation of industrial land, the area of agricultural cultivated land has been reduced. In addition, the generation of greenhouse effect has also accelerated the extinction of species other than human beings, making the food problem become a very important core issue in the 21st century. With limited resources and unlimited human growth, some people have come up with the idea that if food could be increased by high technology, there would not be a day when food would be eaten up. Therefore, with the vigorous development of biotechnology, many things that could not be done before can be done today in the 21st century. Many impossible tasks can be accomplished through biotechnology, such as the use of smears or patches to influence body fat to achieve beauty and weight loss, or the use of Botox is an example of biotechnology.
Since human beings, people have tried to transform organisms. Traditionally, breeding and mating were used to acquire desired biological traits (such as sweet and tasty corn) and to reduce or eliminate undesirable traits (such as natural toxicity). On the other hand, food is a necessity for human growth, and the population has increased rapidly recently. In view of the shortage of food, so-called “artificial food” has begun to emerge. However, the biggest limitation of traditional breeding is that the mating varieties must be the same or similar. In order to break through this limitation, modern genetic engineering technology should be used scientifically to select the genes with some excellent characteristics of organisms accurately and transfer them to another species so that the new genetically modified organisms have the expected specific characteristics.
Data from the Food and Drug Administration (FDA) show that in 1991, Calgene applied for genetically modified tomatoes to transfer antisense polygalacturonase (PG) gene into tomatoes, delaying the maturation and softening of tomatoes. In 1994, the company’s “Flavor” (FLAVR SAVR) tomato was the world’s first approved genetically modified food. The PG gene that promotes the ripening of soft enzymes in delicious tomatoes is inhibited, so its texture is more solid, and it can reduce the damage and deterioration during harvesting, transportation and processing, thus preserving the flavor. At present, however, commercial production of tomatoes has ceased. In 1994, there were 29 applications, including soybeans, tomatoes, corn, potatoes, cotton and melons. Monsanto is one of the big companies.
In addition, in environmental protection, some toxic industrial wastes and contaminated crude oil have been decomposed by recombinant microorganisms. In food, fermentation engineering technology has been used to produce healthy foods such as lactic acid bacteria, Ganoderma lucidum and Cordyceps sinensis. In special chemicals, recombinant enzymes have been used to produce drugs or fibers. Or use it in detergents to decompose dirt. By 2001, there were about 1500 biotechnology companies worldwide, with an annual output value of $30 billion.
The technology of gene recombination and cell fusion is the cornerstone of modern biotechnology. In recent years, many new technologies and new applications have been developed on this basis. For example, protein engineering technology can be used to improve the structure and activity of proteins, and Bionanotechnology can be used to manufacture biosensors, biochips and drugs. Transport systems, tissue engineering technology can use stem cells to repair damaged organs, and animal replication technology can use nuclear transfer to replicate animals, etc.
The development of biotechnology aims at curing diseases, improving the quality of life, providing food that is not scarce and protecting our living environment. However, if not strictly monitored during the development of biotechnology, it may cause harm to human beings or the ecosystem of the earth. Attention should also be paid to its impact on humanity, morality or ecology.
As the application of biotechnology is very extensive and closely related to our daily life, there are often related reports in general newspapers and magazines or news media, so understanding new knowledge of biotechnology should be included in our regular study.
The task of biotechnology is to explore the mystery of life and master the law of life movement.
- Genetically modified products
- Genetically modified food
- brief introduction
The application of science and technology brings convenience, but also brings unknown fears. When the technology of gene recombination is widely used in the development of biology, medicine, agriculture and industry, and may even enter more fields in the future, which deeply affects our lives, we seem to realize that this is an irresistible trend. Therefore, it is more correct to have a positive understanding of genetically modified foods, to think rationally about acceptability, and to leave the right of choice to everyone.
The so-called “genetic modification” refers to the selection of specific genes for individual traits of organisms and the alteration of their genome composition and expression. Scientists use different biotechnologies, such as restriction enzymes, to make target gene fragments, then connect DNA fragments to “vector” DNA molecules, and then transfer vectors to target chromosomes. This process is a kind of genetic engineering.
Different from the traditional breeding method, the transfer of traits is limited to individuals of the same species or similar provenances. Modern genetic engineering technology has broken through the traditional pattern of breeding. It can insert foreign genes from different provenances into plants in a “man-made” way. In addition, genes can even be derived from microorganisms or animals. Body. For example, insecticidal crystalline toxin gene (cry-gene) from Bacillus thuringiensis was implanted into maize, which can also synthesize insecticidal toxin protein produced by cry gene. Therefore, it has insect-resistant characteristics. This maize with cry gene implanted artificially can be called a GMO.
GMO (genetically modified organism) can generally be divided into three categories, namely:
Genetically modified microorganisms (and their products): including microorganisms that can be used as fermented food or as food additives such as enzymes, aminoacids, organic acids, vitamins, pigments and spices.
Genetically modified crops (and their processed products): This is the fastest growing area in GMOs. Transgenic crops such as soybeans, maize, tomatoes and potatoes have been introduced.
Transgenic animals (and their processed products): Salmon transfected with growth hormone gene, but most of them are at the research stage.
Genetically modified foods (GMF = GM foods), also known as genetically modified foods, are processed by GMO. Therefore, all foods derived from genetic recombination technology are called genetically modified foods. How does genetically modified food come into being?
Generally speaking, there are two main ways to implant functional foreign genes into plants. For dicotyledons such as soybeans, tomatoes and cotton, gene transfer is usually achieved by Agrobacterium tumefaciens. Agrobacterium crown can naturally (i.e. without any artificial treatment) infect a wide variety of plants by inserting a segment of its own DNA directly into the DNA of infected plants, so long as the oncogene in Agrobacterium crown DNA is removed, and the foreign gene to be inserted into the stem of Agrobacterium crown. Bacteria infect plants so that additional genes can be transferred to the DNA of infected dicotyledons. Cells containing additional genes in infected plants can be further screened out, and cell culture techniques can be used to produce complete plants containing additional genes. As far as monocotyledons (e.g. maize, wheat and rice) are concerned, Agrobacterium crown is not very effective in infecting them. Generally, the foreign genes to be implanted are coated on tungsten balls, and then the tungsten balls coated with foreign genes are physically introduced into plant cells, some of which have foreign bases. As part of plant DNA, these plant cells containing foreign genes can be screened out and cultured into complete beads because they fall off from the surface of tungsten particles. In addition to Agrobacterium coronatum, plant viruses are often used as vectors, but not all plant viruses have the function of vectors unless the virus can be dispersed between cells via plasmodesmata, and foreign genes must be replicated and the modified viral nucleic acid can infect plant cells. It does not cause symptoms, and the virus must be widely parasitic. Generally speaking, DNA is the main target of gene transfer. RNA-containing viruses are considered only when viruses using DNA are not effective. It is preferable for plant viruses to contain DNA rather than RNA as vectors. However, only caulimo virus and Gemini virus are known to contain DNA, among which caulimo virus and Gemini virus are used. The latter is widely favored by researchers because it can infect dicotyledons and monocotyledons and has a wide range of hosts.
Controversy over genetically modified foods
In recent years, biotechnology has been gradually applied to food production, so the derivatives of genetically modified foods have also been listed on the market. There are still many controversies about the impact of genetically modified food on human body, which requires long-term and extensive research. In order to understand the public’s knowledge and attitude towards genetically modified foods, the Department commissioned a survey on “the public’s knowledge and attitude towards biotechnology and genetically modified foods” by private companies. It is hoped to understand the public’s attitude towards genetically modified foods and their views on labeling policies, which will serve as a reference for future government to formulate relevant laws and regulations. According to.
Threats to the environment include:
(1) threats to non-target organisms and beneficial insects;
(2) reduction of biodiversity;
(3) gene drift and genetic pollution.
The main economic impacts are as follows:
Loss in the market
Although the crop itself will not move, food made from it can be sold everywhere, which also arouses many people’s concerns about genetically modified crops. In 2000, Nature magazine reported that Star Link Corn, an unauthorized genetically modified maize for human consumption, had flowed into Japan’s food distribution network. Star corn is not allowed to be eaten by humans in Japan, although it can be used as feed in the United States, mainly because it contains an insecticidal toxin called Cry9C, which is thought by scientists to cause allergic reactions after being eaten. In the past, about one third of the maize exported by the United States was exported to Japan, while the European Union purchased about 40% of the soybean exported by the United States. Consumers in these areas have doubts about the food safety of genetically modified maize or soybean, which will pose a great threat to future exports of the United States.
For farmers growing organic crops, if they are cross-pollinated or mixed with genetically modified crops, they will suffer serious marketing problems due to poor quality, especially maize and sugar beet, which are cross-pollination plants. In this way, farmers who produce organic agricultural products will have to temporarily withdraw from the organic product market, and their income will drop sharply before they get organic certification again.
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.
Bio Engine Composting
Decomposition Technology of Raw Chicken Manure Composting
Can chicken manure be used as organic fertilizer if it is not ripe? Chinese style
1. Not only chicken manure, but also human manure contains a lot of pathogens, eggs and parasites. Unripe manure can not be directly applied to crops.
2. Chicken manure will dissipate most of the heat in the process of ripening. If it is not fertilized directly, it will cause burning roots and seedlings of plants.
3. Nitrogen fertilizer in chicken manure originally existed in the form of protein. Plants could not use protein directly. Only when protein was decomposed into ammonia after fermentation, can they be used by plants.
How to decompose chicken manure?
Chicken manure must be fully decomposed before it is applied. The parasites and eggs in chicken manure, as well as some infectious pathogens, are inactivated through the decomposition process. Because chicken manure produces high temperature in the process of decomposition, it is easy to cause nitrogen loss. Therefore, it is better to add water and 5% calcium superphosphate before chicken manure is decomposed. Chicken manure has become a good base fertilizer for crop cultivation after full maturation. It can be used for all kinds of flowers, seedlings, crops and fruit trees.
The traditional method is to compost chicken manure for fermentation and maturation, which usually takes 3-4 months to mature. Nowadays, through the rapid biological decomposition technology of Nongshengle chicken manure, the decomposition rate can be 10-20 times faster than the traditional method by aerobic fermentation, and the protein and other substances of chicken manure can be converted into more easily absorbed elements such as nitrogen, phosphorus and potassium. After complete decomposition, chicken manure can hardly smell odor. Fermentation of chicken manure with Nongshengle Fecal Fermentation Fermentation Fermentation Fermentation Fermentation Fermentation has the advantages of low dosage, good effect and fast speed. Generally, chicken manure can be completely decomposed in 7-15 days. If the fermentation material is pure chicken manure, under normal conditions, the C/N ratio is generally less than 20, it should be added with appropriate amount of straw, sawdust and other materials with high C/N ratio. Straw can be added as much as chicken manure to mediate the C/N ratio, and because compost fermentation is aerobic fermentation, straw can enhance the looseness and permeability of chicken manure, which is more conducive to fermentation.
Note: It is recommended to use rice, corn, wheat, sawdust and other plant straw with larger carbon and nitrogen content, and to avoid using straw with smaller carbon and nitrogen content, such as beans. Chinese style
Method of decomposition of chicken manure: Before fermentation, mix all kinds of materials evenly and reserve them. During fermentation, the manure starter of Nongshengle was diluted and mixed with chicken manure mixture at the ratio of 1:200. Then it could be accumulated and fermented. The fermentation process is dumped 1-2 times, and the decomposition can be completed in 7-15 days according to the season.
Knowledge of organic fertilizer clinker: The ratio of total carbon content to total nitrogen content in organic matter is called carbon-nitrogen ratio, and their ratio is called carbon-nitrogen ratio.
C/N ratio of common plants:
- In general, the C/N ratios of gramineous crop stalks such as rice stalks, corn stalks and weeds are very high, reaching 60-100:1.
- The C/N ratio of leguminous crop stalks is relatively small, such as the C/N ratio of general leguminous green manure is 15-20:1.
Effects of different C/N ratios on Composting
The decomposition and mineralization of organic matter with high C/N ratio is difficult or slow. The reason is that when microorganisms decompose organic matter, they need to assimilate about one part of nitrogen to form their own cell body when they assimilate five parts of carbon, because the carbon-nitrogen ratio of microorganisms is about 5:1. In order to assimilate (absorb and utilize) one portion of carbon, four portions of organic carbon are needed to obtain energy, so 25 portions of organic carbon are needed for microorganisms to absorb and utilize one portion of nitrogen. That is to say, the ratio of carbon to nitrogen of microorganism decomposition of organic matter is 25:1. If the ratio of carbon to nitrogen is too large, the decomposition of microorganisms will be slow and the available nitrogen in soil will be consumed. Therefore, when applying organic fertilizers (such as rice straw) with high C/N ratio or composting materials with high C/N ratio, more N-containing fertilizers should be added to regulate C/N ratio. On the contrary, there are too many nitrogen elements in chicken manure, so more carbon elements such as straw should be added. Chinese style
How to reduce the use cost of chicken manure ripening agent:
In order to reduce the use cost of chicken manure ripening agent, the manure fermentation strain (original strain) was developed and manufactured. Users could use the manure fermentation strain to cultivate the fermentation agent by themselves, which could reduce the cost by 10 times. Chinese style
Benefits of Feed Fermentation
- Increase feed utilization rate and reduce feeding cost;
- Detoxification and detoxification, improve palatability and intake;
- Improving animal immunity and reducing fecal discharge;
- Enhance meat quality and flavor to make meat delicious.
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.