Polyethylene:
Polyethylene is a thermoplastic resin produced by the addition polymerization of ethylene. Depending on the polymerization conditions, the relative molecular weight of polyethylene can be obtained from ten thousand to several million. Polyethylene is a slightly white granule or powder, translucent, non-toxic, odorless, chemically stable, resistant to acid and alkali corrosion. Commercially, polyethylene is categorized into low, medium and high density. Generally used for packaging is mainly low density without plasticizers (0.92g/cm3-0.93 g/cm3)
Polypropylene:
Relative molecular weight of 80,000 - 200,000 between. Polypropylene main chain has a methyl side chain. If the methyl group is fully distributed on one side, it is called isotropic polypropylene; if the methyl group is regularly distributed on both sides of the main chain, it is called intermediate polypropylene; if the methyl group is irregularly distributed on the main chain, it is called atactic polypropylene. Polypropylene is usually a semi-transparent solid, odorless and non-toxic, density (0.90g/cm3-0.91g/cm3), mechanical strength is higher than that of polyethylene, good heat resistance. Three kinds of polypropylene, isometric polypropylene production is the largest. The use of titanium trichloride - chlorodiethylaluminum as a catalyst, in the hydrogenation of saturated gasoline so that the polymerization of propylene, isometric polypropylene.
Polyvinyl Chloride:
Relative molecular mass of 50,000-12,000, polyvinyl chloride through the free radical addition polymerization reaction to generate polymer, is a thermoplastic resin. Amorphous white powder, no fixed melting point, density (1.35g/cm3-1.45g/cm3), with good chemical stability. Fused to acetophenone, chlorobenzene, dimethylformamide, toluene-acetone mixed solvents.
Polystyrene:
Average relative molecular mass of about 200,000. Colorless and odorless transparent resin, good light transmission. Glossy surface, flammable, density (1.05g/cm3-1.07g/cm3) with excellent water resistance, corrosion resistance, electrical insulation.
Production methods: body polymerization method, suspension polymerization method, emulsion polymerization method. Here we introduce the body polymerization method. Styrene monomer in the addition of initiators and a small number of additives, now the pre-polymerization kettle for low-temperature polymerization, the preparation of pre-polymer, and then transferred to the polymerization tower of high-temperature heating, segmented to maintain a certain temperature, the end of the reaction is the molten polystyrene extruded into strips, hardened in the water cooled, granular cutting and packaging.
These are the main components of "white pollution", in addition, in these pollutants, but also added plasticizers
agents, foaming agents, heat stabilizers, antioxidants and so on.
[Edit]The current situation of white pollution
First, too much aggression on the land. Plastic garbage also stays in nature for a long time, generally up to 100-200 years.
Second, pollute the air. Plastic, paper and dust fly with the wind.
Third, pollution of water bodies. River, sea water floating on the surface of the plastic bottles and lunch boxes, water above the branches of the tree hanging on the plastic bags, bread paper, etc., not only cause environmental pollution; and if the animals accidentally eat the white trash will hurt the health, and even because of its stranded in the digestive tract can not be digested and starve to death.
Fourth, fire hazard. Almost all white trash is combustible and produces methane and other gases in the natural stacking process, which can easily cause fire accidents in case of open flame or spontaneous combustion, often resulting in significant losses.
Fifth, white trash can be a nesting place for pests, providing food, shelter, and breeding grounds for rats, birds, and mosquitoes, and the residue is often the source of infectious diseases.
Sixth, waste plastic packaging into the environment, because of its difficult to degrade, resulting in long-term, deep ecological problems. First of all, waste plastic packaging materials mixed in the soil, affecting crop absorption of nutrients and water, will lead to crop yield reduction;
Plastic products as a new type of material, lightweight, waterproof, durable, mature production technology, low-cost advantages, in the world has been widely used and is a year-on-year growth trend. Plastic packaging materials in the world market growth rate is higher than other packaging materials, 1990-1995 plastic packaging materials, the average annual growth rate of 8.9%.
China is one of the world's top ten producers and consumers of plastic products. 1995, China's plastic production of 5.19 million tons, nearly 6 million tons of imported plastics, the country's total consumption of about 11 million tons of plastics, of which 2.11 million tons of plastic packaging. Most of the plastic for packaging in the form of waste film, plastic bags and Styrofoam tableware, was discarded in the environment. These waste plastic packaging scattered in urban areas, scenic tourist areas, water bodies, both sides of the road, not only affecting the landscape, resulting in "visual pollution", but also because of its difficulty in degradation of the ecological environment and potential hazards.
According to the survey, 3% of Beijing's domestic waste is waste plastic packaging, totaling about 140,000 tons per year; 7% of Shanghai's domestic waste is waste plastic packaging, totaling about 190,000 tons per year. Tianjin City, the annual waste plastic packaging also more than 100,000 tons. Beijing annually discarded in the environment of plastic bags about 2.3 billion, disposable plastic tableware about 220 million, waste agricultural film about 6.75 million square meters. People jokingly referred to this as "a white blanket on the outskirts of the city".
[Edit paragraph] The harm of white pollution
With the accelerated pace of life, social life is to facilitate the development of hygiene. In response to this demand, disposable Styrofoam lunch boxes, plastic bags, etc. began to frequent people's daily lives. The appearance of these easy-to-use, inexpensive packaging materials has brought a lot of convenience to people's lives. But on the other hand, these packaging materials are often discarded after use, resulting in "white pollution" and becoming a great environmental problem.
The so-called "white pollution" refers to the environmental pollution caused by the discarding of agricultural film, plastic film for packaging, plastic bags and disposable plastic tableware (hereinafter collectively referred to as plastic packaging). Because most of the waste plastic packaging is white, so it is called "white pollution". China is one of the world's top ten producers and consumers of plastic products. In 1995, the total national plastic consumption of about 11 million tons, of which 2.11 million tons of plastic packaging. Most of the plastic packaging in the form of waste film, plastic bags and Styrofoam tableware are discarded arbitrarily. According to the survey, 3% of Beijing's domestic garbage for the waste plastic packaging, annual production of about 140,000 tons; Shanghai 7% of domestic garbage for the waste plastic packaging, annual production of about 190,000 tons. Discarded in the environment of waste packaging plastics, not only affect the cityscape and natural landscape, resulting in "visual pollution", and because of the difficulty of degradation, the ecological environment will also cause potential harm, such as: mixed in the soil, affecting the absorption of nutrients and water crops, resulting in crop yield loss; plasticizers and additives will lead to the exudation of groundwater contamination; mixed with municipal garbage together with the incineration of hazardous gases, polluting the air, damage to human health; landfill disposal will be a long period of time, and will be the most important thing to do. Human health; landfill disposal will occupy land for a long time, and so on. China's annual funding for the treatment of white pollution is about 18.5 million.
[Edit Paragraph]Sources of white pollution
"White pollution", the main harm lies in the "visual pollution", and "potential harm"
2, "potential harm". Waste plastic packaging into the environment, because it is difficult to degrade, resulting in long-term, deep ecological problems. First of all, waste plastic packaging materials mixed in the soil, affecting crop absorption of nutrients and water, will lead to crop yield reduction; Second, discarded on land or in the water body of waste plastic packaging materials, swallowed by animals as food, resulting in the death of animals (in the zoo, pastoral areas and the sea, such cases have been commonplace); Third, mixed into the life of waste waste waste waste waste is difficult to deal with: landfill disposal will be a long-term Third, it is difficult to dispose of waste plastic packaging in domestic waste: landfill disposal will occupy land for a long time, domestic waste mixed with plastics is not suitable for composting, and it is difficult to recycle the waste plastics sorted out because the quality of the waste plastics cannot be guaranteed.
At present, people reflect the strong is mainly "visual pollution" problem, but for the waste plastic packaging long-term, deep "potential harm", most people still lack of understanding.
[Edit paragraph] White pollution prevention and control
Foreign prevention and control of "white pollution" of the relevant situation
As early as 1985, the United States into the average consumption of plastic packaging has amounted to 23.4 kilograms, 20.1 kilograms of Japan, Europe for 15 kilograms. Into the nineties, the number of developed countries per capita consumption of plastic packaging is more (China's 1995 per capita consumption of plastic packaging and other plastic products for 13.12 kilograms). From the consumption point of view, it seems that the developed countries, "white pollution" should be very serious, in fact, it is not. The reason for this is that the developed countries have long been strict attention to the management of the city, few people throw waste plastic packaging, the basic elimination of "visual pollution". Secondly, the harmless disposal rate of domestic waste in developed countries is higher. In the United States, for example, before the 80s, the main way to dispose of waste plastics is landfill, and later found that the plastic long-term non-degradation, after the nineties, they turned to the road of recycling.
Now has established a set of strict classification and recycling system, most of the waste plastic packaging is recycled, a small portion of the conversion into energy or other ways of harmless disposal, but also basically eliminated the potential hazards of waste plastic packaging.
The United States has developed the Resource Conservation and Recovery Act, which makes clear provisions for solid waste management, resource recovery, resource conservation and other aspects of technical research, system construction and operation, and development planning. Ten states, including California, Maine and New York, have introduced a deposit system for the recycling of packaging supplies. Japan in the "Renewable Energy Law", "Energy Conservation and Renewable Energy Support Law", "Packaging Container Recycling Law" and other laws listed special provisions to promote manufacturers to simplify the packaging, and to clarify the manufacturers, sellers and consumers of their respective recycling obligations. Germany in the Circular Economy Act clearly stipulates that whoever manufactures, sells and consumes packaging items has the obligation to avoid generating, recycling and disposing of waste. Germany's Packaging Ordinance will be recycling, utilization, disposal of waste packaging materials and the obligation to produce, sell, consume the right of the goods linked to the recycling, utilization, disposal of the obligation to decomposition and implementation of the goods and their packaging materials throughout the life cycle of the various aspects of the subtle, and therefore has a strong operational and effective.
China's prevention and control of "white pollution" methods and their pros and cons analysis
At present, China began to take measures from the administrative and technical aspects of the prevention and control of "white pollution".
On the administrative side, one is to strengthen management. For example, society is more concerned about the railroad on both sides of the "white pollution" problem, through the strengthening of the management has made significant improvements. Railroad departments from the second half of 1994, in the line along the zoning section dry. Part of the passenger train using bagged garbage, prohibit passengers to the window to discard waste. Cabin crews are not as before, the carriage of garbage directly swept out of the window, but will be unloaded at the station, the station centralized treatment of garbage bags. At present, more and more trains are adopting bagged garbage, and the phenomenon of randomly throwing garbage out of the car is becoming less and less. There have been 29,000 kilometers of lines on both sides of the basic elimination of "white pollution". Practice has proved that strengthening management is an effective means of preventing and controlling "white pollution".
Prohibit the use of disposable plastic packaging that is difficult to degrade. Hangzhou is the first city in China to ban the use of disposable foam fast tableware. Hangzhou in September 15, 1995 by the Bureau of Sanitation, Bureau of Industry and Commerce, Bureau of Health jointly issued a "ban on the use of foam plastic fast food box notice", the notice will be published in the "Hangzhou Daily" for three consecutive days. In the course of implementation, the management found that some individual itinerant vendors are still selling Styrofoam tableware. Recently, the Standing Committee of the Hangzhou People's Congress passed the Regulations on the Management of Cityscape and Environmental Hygiene of Hangzhou, and Article 35 of the Regulations stipulates that it is prohibited to sell or use non-degradable disposable tableware made of Styrofoam. Violators are liable to a fine of 500 to 5,000 yuan. The Regulations will be implemented from September 15, 1997 onwards. Wuhan, Harbin, Fuzhou, Guangzhou, Xiamen, Ningbo, Shantou and other cities have also promulgated relevant policies and regulations to prohibit the local use of disposable Styrofoam tableware, through the adoption of the above measures, to a certain extent, to a certain extent, to reduce the harm of "white pollution". However, from the results of practice, it is difficult to completely solve the problem of "white pollution" by prohibiting it alone, and the cities that have enacted the ban are required to replace the original difficult-to-biodegrade Styrofoam products with paper products or biodegradable plastic products. However, the substitutes cannot compete with ordinary plastic products in terms of price and quality. Therefore, under the conditions of a market economy, it is very difficult to operate solely on administrative orders without considering the regulating effect of economic levers.
Mandatory recycling. Clean waste plastic packaging can be reused, or reused for granulation, oil refining, paint making, for construction materials, etc.. Recycling is in line with the general principle of "minimization, resource utilization, harmlessness" of solid waste disposal. Recycling not only avoids "visual pollution", but also solves "potential hazards", eases the pressure on resources, reduces the load of municipal garbage disposal, saves land and achieves certain economic benefits. This is a good way to treat both symptoms and root causes. But recycling should be in the waste plastic packaging into the garbage before. Re-sorting waste plastic packaging from the landfill is not only time-consuming and laborious, but the utilization value of waste plastic is also very low. Because the sorted waste plastic products are too dirty, it is also difficult to classify them according to the material, and the quality cannot be guaranteed. On the basis of investigation and research, Beijing Municipal Bureau of Environmental Protection (BPEP) determined the technical route of "recycling as the mainstay, substitution as a supplement, differentiation and comprehensive prevention and control" On June 1, 1997, Beijing Municipal Bureau of Environmental Protection (BPEP) and Municipal Bureau of Industry and Commerce (BIAC) jointly issued the "Circular on the Recycling of Discarded Disposable Plastic Meal Containers," which required that the production and distribution of disposable plastic meal containers in Beijing be carried out in the following ways. Beijing, units or individuals producing and distributing disposable plastic tableware (including trays, bowls, cups, etc.) must be responsible for the recycling of discarded tableware, or they can entrust other units to do so. The Circular also stipulates that the recycling rate must reach 30% in 1998, 50% in 1999 and 60% in 2000. Immediately after the release of the Circular, production and distribution units and individuals went to the local environmental protection department to declare their registration and put forward their recycling plans and specific guarantee measures. This is a breakthrough for Beijing to solve the problem of "white pollution". After achieving effective results, it will gradually increase the types and proportion of mandatory recycling of waste plastic products, and ultimately eliminate "white pollution". Tianjin Municipal Environmental Protection Bureau has completed the "Tianjin Prevention and Control of "White Pollution" Project Feasibility Study Report", which puts forward a set of prevention and control programs, and determines that through recycling and reuse to achieve the purpose of saving resources and eliminating pollution. At present, it is formulating the "Recycling Plan", "Pilot Work Operation Chart" and "Pilot Work Progress Outline", and preparing for the establishment of the "Tianjin White Pollution Prevention and Control Project". The company is also preparing for the establishment of the Tianjin 'White Pollution' Prevention and Control Industry Association.
In terms of technology, one is to take paper instead of plastic. The main component of the paper is natural plant cellulose, after the waste is easy to be decomposed by microorganisms in the soil, so you can solve the "potential hazards", but will also bring new environmental problems: first of all, papermaking requires a lot of wood, and China's forest resources are not rich; secondly, the process of papermaking will bring water pollution. In addition, in terms of performance, cost, paper products can not yet compete with plastic products. At present, China also has sugar cane stalks, straw as raw materials for the production of disposable tableware practice, but still in the experimental stage.
Second, the use of degradable plastics. In the production process of plastic packaging products to add a certain amount of additives (such as starch, modified starch or other cellulose, photosensitizers, biodegradable agents, etc.), so that the stability of the plastic packaging material is reduced, easier to degrade in the natural environment. At present, there are 19 units developing or producing degradable plastics in Beijing. Tests have shown that most degradable plastics begin to thin, lose weight, lose strength, and gradually crack into fragments after 3 months of exposure to the general environment. If these fragments are buried in garbage or soil, the degradation effect is not obvious. There are four shortcomings in the use of biodegradable plastics: first, more food consumption; second, the use of biodegradable plastic products can still not completely eliminate the "visual pollution"; third, due to technical reasons, the use of biodegradable plastic products can not completely solve the "potential harm" to the environment; fourth, the use of biodegradable plastic products can not completely solve the "potential harm" to the environment; fourth, the use of biodegradable plastic products can not be completely eliminated. Third, due to technical reasons, the use of degradable plastic products can not completely solve the "potential harm" to the environment; Fourth, degradable plastics contain special additives and difficult to recycle.
Thirdly, it is regulated by law. Through the relevant laws, from June 1, 2008 onwards, to the supermarket shopping will no longer be free to provide plastic bags, to pay for their own separate, which is considered to hope that people reduce the use of plastic bags it.
China's "white pollution" in the treatment of problems
China's "white pollution" in the prevention and control of the main problems are:
1, there is no national specialized regulations
Prevention and treatment of "White pollution" can not rely solely on business or personal self-consciousness, there should be mandatory measures to constrain the behavior of citizens and catering, transportation and other industry staff. For example, enterprises or individuals are required to produce, operate and consume activities of their own waste plastic packaging materials for recycling; the arbitrary abandonment of waste plastic packaging materials, piling up the behavior of penalties and so on. However, so far, China has not formulated national regulations in this regard.
2, the lack of relevant economic policies
To mobilize the recycling of waste plastic packaging, processing, use of enterprise enthusiasm, the need to give these enterprises to preferential policies. Existing comprehensive utilization of preferential policies are not yet sufficient to make waste plastic packaging recycling industry to form a benign market mechanism. In order not to increase the burden on the government, while reflecting the "polluter pays" principle, should be required to generate waste recycling, can not be recycled by enterprises or individuals to pay recycling fees for the recycling of compensation. This practice has been more common in foreign countries, China, there is no such economic policy.
3, the management of the work can not keep up
Cities, scenic tourist areas, traffic arteries, waters of the "white pollution" is mainly caused by poor management. Catering, commercial, railroad, water transport sector of the business activities generated by the waste plastic packaging did not take strict management measures, allowing customers to throw directly on the ground or in the water, and even some of the staff have been collected and discarded to the waste outside the car window or water. City streets and tourist areas of supporting facilities are not sound, shopping malls, restaurants, parks and other busy areas of the density of garbage bins is too low, not yet set up a classification of waste garbage cans. Although the city sanitation department has regulations to prohibit littering waste, but law enforcement, inspection of fewer people, there is no law, there is a ban on the phenomenon is more common.
4, the management of the idea of inconsistency
China's considerable areas of "white pollution" is not enough to recognize the dangers of "white pollution", the prevention and control of "white pollution" has not been put on the agenda. Some places advocate the use of paper instead of plastic or the use of biodegradable plastics to solve the "white pollution", some areas advocate recycling to solve the problem, the management of the idea is not unified.
5, people's environmental awareness also rely on further enhancement
Although the concept of environmental protection of urban residents than in previous years has improved, began to pay attention to environmental issues, but has not yet been implemented into their own actions, discarded the waste, indiscriminate dumping, indiscriminate piling of waste plastic packaging behavior can be seen everywhere. News media reports on "white pollution" are mostly focused on paper instead of plastic and the use of biodegradable plastics and other technologies, the lack of daily behavior of residents to guide the education. Plastic packaging production, business units and consumers have no sense of responsibility, neither the internal motivation to fulfill their obligations, nor the external pressure to recycle, utilize and dispose of waste plastic packaging.
[Edit paragraph] White pollution countermeasures
Summarize the domestic and foreign practical experience in the prevention and control of "white pollution", combined with the current "white pollution" status and its management of the problems that exist in the work of our country to prevent and control the "white pollution". "White pollution" should follow the "publicity and education as the guide, to strengthen management as the core, recycling as the main means to alternative products as a complementary measure" principle.
Prevention and control of "white pollution", first of all, to solve the "visual pollution" problem, so that the city, the landscape has improved significantly. This is mainly rely on publicity and education, guide the public to form good habits; at the same time to strengthen the management of the law, to promote enterprises and individuals into their own waste plastic packaging materials properly collected and disposed of. Prevention and control of "white pollution", it is more important to solve the waste plastic packaging on the ecological environment of long-term, deep-rooted harm. This is mainly through the development and implementation of recycling-friendly regulations and economic policies, the implementation of comprehensive recycling of waste plastic packaging; prevention and treatment of "white pollution", should also strengthen the research and development of alternative (green) packaging supplies in line with the actual. Now on the acceleration of China's prevention and control of "white pollution" process to put forward the following countermeasures:
1, strengthen publicity and education. Prevention and control of "white pollution" is a systematic project that requires various departments and industries **** with the efforts of society as a whole and the active participation of all citizens. To vigorously carry out publicity and education to enhance people's awareness of the harm of "white pollution", to enhance the environmental awareness of society as a whole, and to educate people to develop good hygiene habits. In their own strict compliance with environmental regulations at the same time, actively stop the bad behavior around.
2, unified ideological understanding, strengthen management. In accordance with the "publicity and education as the guide, to strengthen management as the core, recycling as the main means to alternative products as a complementary measure" principle of prevention and control, one is to strengthen the "white pollution" harmful publicity, guide and educate the public to consciously prevent and control the "white pollution", "white pollution", "white pollution", "white pollution", "white pollution", "white pollution", "white pollution" and "white pollution". "White pollution"; second, a large number of waste plastic packaging industries (such as railroads, water transport, civil aviation, tourism, hotels, restaurants, catering, retail, etc.), to strengthen the management, to change the phenomenon of no one is responsible for the disordered piling, randomly discarded; third, to take mandatory measures from the recovery of centralized generation of waste plastic packaging (such as disposable foam lunch boxes), progressive recycling, and the use of alternative products. Foam lunch box) to start, and gradually improve the recycling rate of waste plastic packaging; four is to strengthen the development of alternative packaging products, research, and efforts to reduce the amount of waste plastic packaging, etc..
3, as soon as possible to develop and promulgate national prevention and control of "white pollution" of the relevant laws and regulations, clear producers, sellers and consumers recycling of waste plastic packaging obligations and legal responsibilities. Should be the production of plastic packaging, business, consumption and other links, respectively, to develop specific control measures and guidance policies to control the amount of waste plastic packaging is not easy to recycle, encourage to improve the recycling rate of waste plastic packaging.
4, the development of appropriate economic policies, the establishment of market economic conditions to eliminate "white pollution" benign operation mechanism. The use of economic means to encourage and promote the waste plastic packaging "reduction, resource utilization, harmless", saving and comprehensive utilization of resources, prevention and treatment of "white pollution", to protect the ecological environment.
The Earth is our home for survival, and provides us with such a beautiful environment. However, with the rapid development of social economy and the high concentration of urban population, the production of domestic waste is gradually increasing, and our home is surrounded by garbage.
In recent years, due to a large number of waste packaging plastic film, plastic bags and disposable non-biodegradable plastic tableware use of the surge, and arbitrary abandonment, the large and medium-sized cities are generally formed a serious white pollution. It has been listed with the car exhaust, phosphorus detergents together as this year's three major focuses of China's environmental protection governance.
Plastic is a kind of difficult to deal with the life of the garbage, it is mixed into the soil can affect the crop absorption of water and nutrients, resulting in crop yield reduction; landfill, occupy the land and hundreds of years can be degraded. Large quantities of plastic can also be accidentally ingested by animals, as in the case of the elk in Beijing's Nanyuan Park, who died after eating a plastic bag that flew in from a nearby garbage dump. Plastic is easy to form bundles, it can even block the water flow, resulting in water conservancy facilities, urban facilities failures, resulting in disasters.
China's production and use of foam tableware is very large, food packaging, shopping and food shopping plastic bags used in the number is also alarming. According to a rough estimate, this century, China's white trash about more than 8 million tons. Plastic products are one of the most difficult to deal with all the domestic waste, has been a worldwide problem, generally speaking, the use of sanitary landfills, high-temperature composting and incineration of these three methods, basically can make the waste treatment to achieve the reduction of quantitative, resource and harmless. However, the situation in China is not optimistic, since the former garbage collection and treatment is far from forming an orderly system. Take Beijing for example, the garbage collection has not completed the bagging of garbage, not to mention the classification of collection.
Although incineration can destroy plastic bags, but the construction of a waste incineration plant is the same size landfill 20 times the investment. As for the practice of artificial degradation to produce organic oil, the need for higher purity of plastic products, large-scale processing is not realistic. Therefore, sanitary landfills have become the main way to be able to collect plastics at present. Beijing has built three sanitary landfills, Asuwei, Beijingshu and Anding, with a thick impermeable layer at the bottom of the landfill, and as the garbage piles up, the top is constantly covered with soil, and then the vegetation is recreated, in order to ensure that the garbage is in a confined space around the scope of the space, and will not pollute the groundwater, soil and the surrounding air. However, in order to stabilize the landfill, for example, an area of 300 acres of a piece of land is only enough for a Xuanwu District of Beijing to use for 14 years.
The boycott of non-biodegradable plastics was echoed by some shopping malls not long ago, which tried to sell biodegradable garbage bags, but there were few takers because they cost more than 1 yuan and couldn't bear much weight. Wankelong advocate the use of cloth bags, the effect is also not ideal.
The best way to solve the problem is to tackle both the symptoms and the root causes, experts believe that, on the one hand, should be timely and effective treatment of living garbage, on the one hand, with the ability to degrade, easy to degrade the products instead of plastics.
In November 1998, a kind of straw made of disposable tableware for the first time on the fast food table of the Beijing Parkson Shopping Center. This kind of tableware is not only safe and hygienic, but also a one-time use into the soil that is fertilizer, into the water can become fish feed, discarded by the side of the road, a few days after the wind went away. In December 13, 1998 "green disposable tableware exchanges", more than 100 companies showed their rice husk, pulp, starch and other raw materials for the production of tableware. A biodegradable disposable fast-food box has passed the test after nearly three years of research by more than 30 researchers from the Beijing Light Research Institute. The test confirms that the lunch box is exposed to nature after use, and all of it will be changed into water and carbon dioxide within 40 days. This lunch box to starch (corn, tapioca starch) as raw materials, adding annual plant fiber powder and biological waterproof glue sprayed into the mold heated foam molding. A variety of newborn alternative products are in their infancy, but have not yet reached the level of mass production and promotion.
In addition; the public's awareness of environmental protection is still relatively backward, which is actually an important factor hindering the management of white pollution. The first step in the treatment of white trash is the separation of garbage, which is only expected to be carried out after the majority of people's conscious environmental protection awareness is established. Therefore, the most important point to combat white pollution is to raise the environmental awareness of everyone. Because white trash takes more than a hundred years to degrade naturally in nature, solving its pollution problem can really be called a hundred-year problem.
Prevention and control of white pollution
1, stop using disposable tableware and ultra-thin plastic bags. As disposable plastic tableware is difficult to degrade, many cities are now promoting the use of green tableware - paper tableware, because cellulose can be degraded by microorganisms. But many environmental experts believe that it is not wise to use paper tableware instead of foam plastic tableware. First of all, paper tableware will also bring visual pollution, because their degradation speed is not fast, often in dozens of days or even months will not be completely degraded. Secondly, the production of paper tableware, in addition to grass pulp, rice pulp, but also to add about 1 / 3 of the wood pulp, if the full promotion, is bound to cause a large number of wood consumption, leading to increased deforestation. It is worth noting that China's forest coverage is only 13.92%, per capita forest area is equivalent to only 17.2% of the world's per capita level, ranking 112th in the world. Thirdly, pulp has always been a major consumer of water, energy and sewage. Pulping process requires a large amount of water, and China's per capita water consumption in the world ranked 88, has been listed as the world's 12 water-poor countries on the list; if the sewage is untreated, discharged directly into the river, will cause water pollution; paper tableware molding needs to be dried immediately after the molding, which requires the consumption of large amounts of energy. And China's energy structure is mainly coal-fired, which will increase the content of SO2 in the air, causing acid rain. Therefore, whether from the perspective of environmental protection, or from the perspective of saving resources, do not use disposable plastic tableware and paper tableware is a good thing. Any disposable tableware is not only detrimental to the environment, but also the biggest waste of resources. In our daily life, we should refuse to use ultra-thin plastic bags to buy food or to hold food, buy food available vegetable baskets or thicker plastic bags, to avoid the use of disposable, so as to reduce the environmental pollution of plastic bags.
2, recycling waste plastic and make it resourceful is the fundamental way to solve white pollution. In fact, plastic and other materials than, there is a significant advantage: plastic can be easily recycled over and over again. After recycling, waste plastics can be classified, cleaned and then heated and melted to become products again. In terms of composition, polyethylene, polypropylene and polystyrene are all composed of hydrocarbon elements, while fuels such as gasoline and diesel are also composed of hydrocarbon elements, only with smaller molecular weights. Therefore, these types of plastic insulation air heated to high temperatures, so that the cracking, the cracking product for fractionation, can be produced gasoline and diesel fuel.
In recent years, some countries vigorously carry out the 3R movement: that is, the requirements of waste plastics to achieve the reduction (Reduce), reuse (Reuse), recycling (Recycle). At present, in Germany, Japan, the United States and other countries, due to the importance of recycling packaging materials, has realized the production, use, recycling, reuse of plastic virtuous cycle, from the root to eliminate white pollution.
3, research and development of degradable plastics. Degradation of plastics with the same use of ordinary plastics, but in the completion of its use of function and abandoned, its chemical structure can be changed under certain conditions, so that the polymer decomposition of molecules into molecules of smaller molecular weight, and finally, assimilated by the natural environment. There are three types of degradable plastics: photo-degradable plastics, biodegradable plastics and biodegradable plastics. But now many degradable plastics are not 100% degradable, but just change the plastic into plastic fragments. It is reported that China's Shaanxi Yangling Agricultural High-Tech Industrial Demonstration Zone has successfully developed 100% degradable plastic. It is a physical combination of starch and non-degradable plastics crushed into nanoscale by special equipment, and then the ratio of the two is controlled within a certain range. Agricultural film produced by this new technology, after four to five years of field tests, the results show that in 70 days to 90 days, starch completely degraded to H2O, CO2, plastic into the soil and air harmless fine particles, and in 17 months the same completely degraded to H2O, CO2. now this plastic has been put into mass production. At present, degradable plastics are still far from being used on a large scale in the world. The development and use of degradable plastics can only be used as an auxiliary measure to solve white pollution.