According to the voice of the economy, "the world company" reported that the University of California Industrial Ecology team estimated the total amount of plastic on Earth, 65 years ago was invented so far, the human production of about 8.3 billion tons of plastic. It is equivalent to 25,000 New York Empire buildings, equivalent to the sum of 1 billion elephants, including plastic bottles, plastic bags and other plastic products.
Plastic is the United States of America Beckland in 1909 synthetic invention, he used phenol and formaldehyde synthesis of phenolic resin. Plastic is a polymer compound, can be free to change the composition and shape of the body, impact resistance wear, good insulation, low cost But the shortcomings are also obvious, classification and recovery is difficult.As the US California scientists team estimates that only 30% of the plastic is recycled, and 70% of the plastic has become garbage, most buried under the land, there are a lot of garbage floating In the ocean.
Which plastic can be recycled? Wuhan University of Technology School of Materials Professor Dong Lijie explained this.
Dong Lijie: 'After the melting of thermoplastic plastic can be formed, recycling is easy. Because it is only after the early purification, sorting classification, and then put the same conditions, or can make new products. Such as plastic bottles, There is also a thin film, there is a big class.
Technically difficult to achieve, why the recycling rate of only 30% recycling rate?
Professor Dong Lijie said: 'On the recovery of plastic, plastic bottle recycling system is relatively perfect. There are also some enterprises in the use of waste plastics. There are some products will be used when the scrap used to apply. If you can in large quantities, the same But the different materials of the forming conditions are different, if not a class, it is difficult to common use in the plastics industry, we are still very concerned about the recycling, after all, the plastic The source is oil, hoping to re-use it as much as possible.If you want to expand the coverage of plastic recycling, but also need to establish some of the corresponding mechanism.Many countries, for packaging materials will have a strict classification, according to different types Each household first good, this will increase its recycling rate.
China's current garbage collection classification rely on most of the roadside waste recycling, garbage disposal of individuals, such a low efficiency of the problem?
Professor Dong Lijie: 'It is neither high enough nor low enough, there are a lot of plastic looks the same, but in fact different types. If you are mixed together, some of the production of a product may not be very suitable.
70% of the plastic into garbage, in the land and sea water, plastic degradation of how? How long will it take?
Professor Dong Lijie: 'There is no complete separation of plastic products, may be burning and landfill. If it is burning, there will certainly be gas, heat and other issues; landfill is not a very good way, because the long-term landfill to the land It is also a problem. Most of the non-degradable plastic's existence is very long, it may be 50 years in the soil, 100 years will not be bad. Into the ocean of plastic there is no way to break down. Seawater environment for such a generic plastic, Some academic articles will be mentioned, for some plastic it may be long into small particles, etc., but for many plastics, its existence is still very long. Seawater environment than our current There are some changes in the water quality, but not the limit, such as strong acidity or strong alkaline, will contribute to the degradation of the material.There are some of the membrane material degradation requires a high energy, so it is more difficult.
Someone once made plastics the greatest material discovery of the twentieth century, but now the team of scientists believes that plastics will be the burden of the earth, and that the total weight of plastic on earth will exceed 12 billion tons by 2050.
Professor Dong Lijie said: 'We never think that it will be how the earth, in fact, our use of plastic, such as: how can we recycle it, as much as possible to maximize the use of the world there are many Country, the most typical of Japan, it will be the establishment of the recycling system is perfect.For every person who makes the material, any material is a very valuable resource, the problem is just how to use it.