White pollution status and treatment technology (I)
I, "white pollution" status
1. What is "white pollution"
"white pollution" first came from the metaphor of the impact of mulching film remaining in farmland soil on farmland and ecological environment. We all know that China is the country with the largest yield and coverage of mulching film in the world, and the wide application of mulching film has become an important agricultural material for agricultural production increase, Once known as the "white revolution", plastic mulch is not easy to recycle and degrade after use, and its residues accumulate in farmland soil for a long time to form soil hardening, affecting crops to take root, ventilate and water, and even reduce production. It is also known as "white disaster" or "white pollution". In recent years, with the economic development, scientific and technological progress and the continuous improvement of people's living standards, the application of disposable plastic packaging film bags and fast-food tableware has increased rapidly. Some of its waste has been discarded and scattered in the natural environment at will, and some of it has followed domestic waste into the urban solid waste treatment system. Because most of China's urban waste treatment is not sanitary landfill or incineration to recover heat energy, but waste relocation, Transported from the city to the suburbs for open stacking or shallow burial, in case of strong winds, light and bulky plastic waste, especially ultra-thin plastic bags, will be scattered everywhere with the wind, flying all over the sky (jokingly called "film fluttering") or hanging on tree branches or telegraph poles (jokingly called "ten thousand national flags"), plus polystyrene foam tableware (jokingly called "white corridors") that are randomly discarded on both sides of the railway, as well as scattered in rivers and lakes Plastic residue films and films in drainage and irrigation ditches are vividly compared to "white pollution" and are criticized by the society
in recent years, people's lifestyle has changed from "frugality" to "consumption", and the use of disposable goods has increased significantly, but citizens' enthusiasm for recycling waste is far less than that in the 1950s and 1960s. At the same time, due to people's lack of understanding of the environmental problems caused by plastic waste, disposable plastic products are discarded casually and everywhere after use, which leads to new environmental problems
the main reason for white pollution is that plastic waste has not been properly managed and treated, such as: ⑴ urban sanitation infrastructure is in arrears, and garbage collection containers and disposal facilities are seriously insufficient; Garbage is not collected by classification, and recyclable garbage is not recycled; The final disposal method of garbage basically stays at the level of bare stacking or shallow burial; Some towns use the banks of rivers, rivers and lakes as natural garbage dumps. (2) in traffic Lu kerstan agreed: "Some other automobile manufacturers have said that window industries such as tourism, except the railway system, have not established a garbage collection system matching production and operation, and let the garbage generated in the process of operation go by itself. ⑶ management is weak. There is a lack of relevant laws and regulations for plastic packaging waste, and people's environmental awareness is relatively weak, resulting in widespread abuse and random littering, which is not caused by plastic materials themselves.
"White pollution" mainly refers to the two negative effects of "visual pollution" and "potential harm" to the environment
visual pollution refers to the impact of plastic waste scattered in the environment on the city appearance and landscape, which will block and damage the valves and oil routes. For example, polystyrene foamed plastic tableware scattered in the natural environment, on both sides of the railway, rivers and lakes, and ultra-thin plastic bags flying or hanging branches will be put into production and on the market in the near future. These will bring adverse stimulation to people's vision, which is called "visual pollution". The people reacted strongly to this
potential hazards refer to the long-term deep-seated environmental problems caused by the difficulty of degradation of plastic waste after entering the natural environment. Its harm includes the following aspects
⑴ plastic film waste accumulates in a large area of soil for a long time, causing soil hardening, affecting the absorption of nutrients and water by crops, resulting in crop yield reduction
⑵ plastic waste discarded on land or in water is swallowed by animals as food, resulting in death
⑶ plastic waste entering domestic waste is light in weight and large in volume, which is difficult to deal with. If it is landfilled, it will occupy a lot of land, and it is not easy to degrade for a long time. Domestic waste mixed with plastics is not suitable for composting. At present, the strongest reflection in society is "visual pollution", and most people still lack sufficient understanding of the "potential harm" of plastic waste to the environment
the term "white pollution" is not scientific and rigorous in terms of formulation, but as a description of a phenomenon, it is understandable as a reflection of the concerns of the general public about environmental pollution control. However, it is not comprehensive to refer to the term "white pollution" only to disposable plastic waste at present. In recent years, many substitutes have been developed, such as paper, pulp molding, plant fiber, whole starch and other tableware. Although they use natural materials as raw materials, they are relatively perishable and degradable, but due to the addition of waterproof and oil proof agents, it also increases the difficulty of decay degradation and recycling. Practice has proved that it still needs a certain period for them to return to nature after use, and their degradation speed depends on environmental conditions to a large extent. Therefore, the collection and treatment of any kind of degradable disposable tableware and disposable plastic product waste should be strengthened, and it should not be thrown around, so as to avoid the recurrence of the new "white pollution". Polystyrene foam, as a lesson from the past, should be taken as a warning. Therefore, the exact definition of "white pollution" should be: the pollution and harm to the urban landscape and ecological environment caused by the waste of disposable consumer goods of any kind of material, if it is not properly recycled and disposed of and left to be discarded everywhere
on the other hand, we must also have a correct understanding of plastics. We cannot equate "white pollution" with plastic materials. As we all know, plastic is a new material with excellent comprehensive properties. It is not only a kind of material, but also a kind of consumer goods. In general, it is also a kind of material. Any substance has its life cycle. The whole process of reaching the end of its life cycle is the degradation process. Plastic itself is also degradable, but its degradation can improve the dimensional accuracy of products. The solution process can be delayed, restrained, strengthened and promoted by taking certain technical measures according to the requirements of product application. The plastic aging (embrittlement and hardening) we usually see is a characterization of degradation, but it has a long cycle to reach the end point of degradation. Moreover, the daily commonly used plastic products have been stabilized by adding light, heat stabilizers, antioxidants, etc. to delay or inhibit their inherent degradability, and most of the plastics are thermoplastics, which can be recycled. Therefore, plastic products are solid, durable and widely used. They have penetrated into all sectors of the national economy and all areas of people's lives, and have played a positive role in promoting the technological progress of all sectors and enriching and facilitating people's lives. Today, it has been listed as four pillar materials together with steel, wood and cement, which is the main reason for the rapid growth of plastics. On the other hand, in order to meet the requirements of environmental protection, degradation promoters can be added to disposable plastics. Plastic products can accelerate degradation under certain environmental conditions after completing its use function. Therefore, it has become a new member of the plastic family with environmental protection functions
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