The white pollution in Shanghai and Its Countermea

Shanghai's "white pollution" and its remediation countermeasures

1. Preface

plastic products have penetrated into all fields of people's production and life because of their low price and good quality. The annual output of plastic products in China has been nearly 15.34 million tons. Plastics are high molecular materials with many categories. Plastic products with olefins as raw materials include polystyrene, polyethylene, polyvinyl chloride, polypropylene, etc. They are not easy to decompose in the natural environment. Foamed polystyrene disposable lunch boxes and polyethylene plastic bags, which people are most exposed to, have small density, large volume and do not decay. If they are discarded at will, they will damage the city appearance and cause visual pollution. In the Three Gorges tourist area and the river, plastic waste floats and blocks the water flow, affecting the normal operation of Gezhouba hydropower station. The nose team is mainly responsible for evaluating the odor grade of plastic produced by Jinhu Rili and participating in the evaluation of the odor grade of car factories. In Shanghai, plastic waste also enters small and medium-sized rivers and eventually pollutes Suzhou River and Huangpu River. Plastic waste entering the garbage is also difficult to deal with. The disposable agricultural film mixed into the soil after use, cutting the capillary, affecting crop growth, leading to agricultural production reduction, is a potential pollution. The content of plastic waste in Shanghai's domestic waste is about 7%, with an annual total of 290000 tons. Only one-time plastic lunch boxes are 3363 tons a year, about 673million, with an average of 9.2 tons per day, about 1.84 million

second, the treatment method of "white pollution"

Plastic waste is vividly compared to "white pollution". The national annual fund for the treatment of "white pollution" is as high as 3billion yuan, but it has little effect. Therefore, there are various topics on how to rectify "white pollution". Landfilling and incineration is a helpless strategy. In Shanghai, plastic waste is collected together with land garbage and transported to the landfill. It is reported that plastic waste will not degrade for 200 years under dark conditions. In the long run, Shanghai's limited area will eventually have no land to bury. Agricultural film pollution is also spreading in the densely populated rural areas of Shanghai. In addition, the incineration method, although it can recover part of the heat energy of plastic waste, occupies less land, but the investment is large, and what is burned is resources. More importantly, it will produce harmful smoke and pollute the atmosphere. Therefore, the above two methods are not good strategies. It is difficult to replace plastic with paper. Although replacing plastic with paper can degrade in the natural state and make up for the fatal injury of non degradable plastic products, it also exposes many weaknesses that are difficult to compete with plastic products: the price is several times higher (a plastic fast food box costs 8 points, while paper ones cost 34 cents); Papermaking produces waste water and pollutes the environment; Wood consumption; In addition to reeds and other wild plants, using straw, chaff and straw that have been applied with chemical fertilizers and pesticides as raw materials will cause paper products to be polluted and attacked by bacteria, which cannot ensure hygiene; The waterproof performance of paper is poor, and the appearance needs coating or additives, which is bound to increase the cost and affect recycling. In addition, paper products cannot be compared with plastic products in terms of earthquake resistance, heat insulation, light weight and other properties

in September 1998, five ministries and bureaus of the state jointly issued a notice prohibiting the use of disposable foamed plastic tableware on ships (i.e. two lines and one lake) in inland waters such as railway stations, cars, the Yangtze River and Taihu Lake, and using cartons and Degradable Polypropylene lunch boxes instead, which achieved preliminary results. Trains and ships operate in a closed way, and paper lunch boxes can be used forcibly. Moreover, the price of lunch boxes on board is high. Calculated at 10 yuan per passenger, a few cents per paper lunch box accounts for a small proportion, which is acceptable to passengers, but it is difficult to have market competitiveness on urban land. Foaming is banned in some cities. 2. The indication deviation of plastic lunch boxes caused by incorrect dynamometer devices finally ends up in nothing. The main reason is the high price of substitutes. Degradable plastics need to be explored. At present, degradable plastics can be divided into three types: biodegradable, photodegradable and chemical degradable. In essence, it is the addition of starch, cellulose, photosensitizers, additives, etc. into the plastic, which begins to disintegrate and degrade after about 3 months. Remember to turn off the controller and computer. The fruit is not ideal. It can only degrade starch and cellulose, while the plastic turns into fragments and remains in the soil. Strictly speaking, degradable plastics added with starch do not have degradation mechanism and function, because the main chain of polymer compounds such as polyethylene will not be broken and degraded due to starch degradation. Many kinds of photodegradable plastics must be exposed to sunlight to cause macromolecular degradation. When they are buried underground without sunlight, they lose their degradability. Degradable plastics are still in the experimental stage at present, and the price is also high. Before they are degraded, there is also the problem of "white pollution". Their degradation speed is also restricted by the environment and season. The South and summer are warm and easy to degrade; It is dry and cold in the north and winter, and it is difficult to degrade. At present, there is no final conclusion whether some additives have hidden dangers to human health

recycling, turning waste into treasure. After taking the road of landfilling, incineration, paper generation, degradation and so on, foreign countries feel that it is not a good plan, and return to the road of recycling, so as to make the best use of cheap and good plastics, form a virtuous circle, and is conducive to sustainable economic development. Some countries also have regulations for this purpose, such as the United States has the resource protection and recycling law, Japan has the renewable resources law and the packaging container recycling law, Germany and South Korea have the packaging regulations, and Germany has the circular economy law, etc. The recycling methods of plastic waste generally include: physical recycling - hot melting and granulation, making recycled products, such as buttons, zippers, waterproof materials, building materials, thermal insulation materials, etc; Chemical recovery - high temperature cracking into monomers, making chemical raw materials, making coatings, adhesives, gasoline, modified asphalt, etc. Formulate policies and skillfully use the large and clean packaging materials of the lever body, which is correspondingly convenient for centralized recycling. Some large enterprises directly set up workshops to recycle plastic waste granulation, which is profitable. There are also a few private waste recycling stations that recycle clean packaging materials, but the price is low, less than 1 yuan per kg, and few shippers. The foaming fast-food boxes full of people's attention, each of which is about 5g, have a wide range and are dirty, making it difficult to recycle. Beijing and Tianjin set the recycling price of foam lunch boxes at more than 2 yuan per kg, and the market recovery rate increased, reaching 70% in Beijing and 30% in Tianjin

the author once asked several scavengers in Shanghai, who said that if the purchase price of plastic waste increased, they would actively pick up and sell it. In fact, the source of these recycling and disposal fees, According to the environmental protection law, "Whoever pollutes, who governs" "In principle, it will be levied on the manufacturers of plastic products. The seven major plastic lunch box manufacturers in Shanghai have expressed their intention to accept the regulations. Of course, these costs will eventually be included in the costs and shared with consumers, which is in line with the principle of consumers' burden and environmental governance. In addition, the increase in the price of low-cost plastic lunch boxes will help narrow the price gap between paper and plastic lunch boxes. In the future, paper and plastic products will exist at the same time for a long time. Who wins Who bears the burden depends on the market price and environmental benefits. Manufacturers committed to recycling should be given preferential economic policies, tax reduction and exemption, and the sales channels of recycled products should be unblocked. Establishing institutions and strengthening management are important means to control "white pollution" at present. To strengthen management, we must establish an authoritative management organization. The management organization should establish a strict classification and recycling system. All walks of life, all lines and points, catering, tourism, stations, stores, transportation departments, streets, alleys, schools, and vegetable farms should have their recycling networks. Within a certain range, they should be equipped with hot-melt pre plasticizing devices to reduce the volume of plastic waste and facilitate transportation

recycling work should be planned, organized and followed up, and a long-term management mechanism should be established. The funds of the management organization can be disbursed from the recycling and disposal fees without increasing the burden on the government. The establishment of this recycling and disposal system will contribute to the employment problem of society. Publicity and education, the participation of the whole people, vigorously publicize relevant laws and regulations and scientific knowledge to the society, and make the public realize that "white pollution" is a public hazard, but it can also be transformed into wealth. To make the public understand that turning harm into benefit is beyond the ability of some departments and individuals. It can only work by relying on all walks of life, everyone's participation, strengthening environmental awareness, establishing social morality, and groups and individuals abiding by laws and regulations. Laws and regulations and early exit legislation are fundamental. The State Environmental Protection Administration is drafting the regulations for the implementation of the law on the prevention and control of environmental pollution by solid waste, and Shanghai is also drafting the measures for the prevention and control of "white pollution". The regulations have more specific provisions on the control of "white pollution", including prevention and control principles, competent authorities, production and sales, use management, recycling and disposal, alternative products, publicity, taxation, legal inspection of whether the ball sockets and ball joints of suspenders and large lever connectors have oil stains, etc. It is suggested that the laws and regulations embody the principle of prevention and treatment, especially in the main links of production and manufacturing, sales and circulation, consumption and use. For example, there should be regulations on the simplicity and complexity of packaging, and phenomena such as four-layer packaging of several biscuits can no longer be allowed to spread

III. conclusion

the plastic industry is the product of scientific and Technological Development and the symbol of human civilization and progress. Plastic itself is not the culprit of environmental pollution, but people's lax management. The remediation of "white pollution" should be active and comprehensive, which requires both a social management mechanism and a sense of advance on the production line. When designing and producing packaging materials, we must consider the recycling, regeneration and utilization of waste. At present, Shanghai should first do some research work to prepare for the comprehensive rectification. Remediation of "white pollution" is also a hard work and a huge and complex social system project. The prevention and control principle of "taking publicity and education as the guide, strengthening management as the core, recycling as the means, and product substitution as supplementary measures" should be implemented. We will ensure implementation by means of administration, economy and science and technology. As long as the government pays attention and the measures are implemented, there will be results, so as to further promote the economic construction and spiritual civilization construction of Shanghai. (excerpted from Shanghai "city Herald" 99.4.22)

editor's note: the argument in the article that... Degradable plastics with starch addition do not have degradation mechanism and function, because the main chain of polymer compounds such as polyethylene will not be degraded by chain breaking due to starch degradation... There is a market in China, Here is the degradation mechanism of starch filled polyethylene proposed by many experts at home and abroad after long-term test for reference: polyethylene plastics have been considered not to be biodegradable in the past. According to the research of Japanese chemical inspection association researcher Takemitsu and others for more than ten years, they have a relatively clear basic understanding of the biodegradability of polyethylene:

1 Polyethylene is biodegradable, and its biodegradation factors are preliminarily mastered. By adding these factors, the biodegradability of polyethylene can be improved

2. Adding modified starch to polyethylene can improve its biodegradability. Its basic degradation mechanism is to degrade the starch contained in plastic products, which will be rapidly degraded by enzymes secreted by microorganisms in soil (or garbage) in a short time to form cavities, resulting in the decline of mechanical properties of products, and with the formation of cavities, the surface area will expand, thereby increasing the contact surface with soil; At the same time, the self oxidant added in the formula reacts with the metal salt of the soil to produce peroxides, which cause the chain of polyethylene to break and degrade into low-molecular compounds that are easy to be swallowed by microorganisms, and with the passage of time