Recycling status of pet waste bottles in Shanghai

2022-07-25
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Recycling of pet waste bottles in Shanghai with the rapid development of the beverage industry, PET bottles have become one of the fastest growing and most widely used packaging containers in the world. Promoting the recycling of PET bottles has become the focus of attention all over the world. Shanghai has achieved good results in promoting the recycling of PET bottles through various channels. But the problem of water pollution caused by this also needs attention

pet bottles not only have excellent performance, but also have high recycling value and are easy to recycle. PET bottle is recognized as one of the most excellent plastic packaging materials for environmental protection at home and abroad (some people even call it green packaging materials). Therefore, after the advent of PET bottles, especially after people put forward the concept of sustainable development strategy, it has been highly valued by the industry and has become one of the fastest growing and most widely used plastic packaging containers in the world

in recent years, Shanghai has actively carried out the reduction, recycling and harmlessness of packaging waste, especially in the recycling of pet waste bottles. The recycling of pet waste bottles in Shanghai is very representative nationwide

recycling rate of pet waste bottles

among all kinds of plastic packaging wastes in Shanghai, pet waste bottles have the highest recycling rate, and their recycling rate is close to 100% (at least more than 95%). According to the Shanghai municipal waste management office, at present, there is no trace of PET bottles in Shanghai municipal waste. However, other recyclable plastic packaging wastes, such as EPS tableware, which is listed as a key product of Shanghai environmental governance, are still common in Shanghai's urban garbage, although the recycling rate has been close to 70% through various efforts

pet waste bottle recycling rate is high, mainly due to the high utilization value of pet waste bottle recycling material. The recycled PET pellets from waste PET bottles have been successfully reused in spinning and blow molding; Its deep-processing products (such as carpets and other fabrics or pesticide bottles) have been fully affirmed in terms of performance or economy in practical applications. Therefore, the price of recycled PET pellets is quite high, which can reach about 70% of that of new pet. Due to the large profit margin, pet waste can eventually have a high purchase price (at present, the purchase price of general plastics in Shanghai is only about 0.8 yuan/kg, while the purchase price of pet waste bottles is more than 1.5 yuan/kg)

secondly, the mass (weight) of pet waste bottles is large. For example, the mass of a coke bottle with a capacity of 1.2 liters is more than 40 grams, and the mass of a mineral water bottle with a capacity of 500 ml is more than 20 grams. The product quality is high, and the price of a single product is high during recycling, which makes the recycling easier. The significant economic benefits have strongly promoted the smooth progress of all aspects of PET recycling, effectively preventing the flow of pet waste bottles into the garbage dump, so that the pet waste bottles in Shanghai can be fully recycled

recycling network of pet waste bottles

at present, there are mainly two recycling networks of pet waste bottles in Shanghai. The first is the waste material recycling system led by the former Shanghai Municipal Commission of Commerce. The grass-roots recycling personnel of the network are mainly composed of "40" and "50" personnel. The system has transfer stations in all districts and counties, and waste recycling and delivery points are set up in communities where residents are concentrated. Each waste recycling and delivery point is listed for operation in the community. The recycled PET waste bottles are concentrated in the transfer station and sold to regeneration and treatment units. In addition, the scope of utilization continues to expand. A recycling network of waste PET bottles outside the city is recycled by foreign unlicensed street vendors or fixed recycling points. The collected waste PET bottles are purchased and concentrated by middlemen and sold to pet waste bottle recycling and processing units. A large part of them are transported to Jiangsu, Zhejiang and other surrounding areas for recycling treatment

pet waste bottle regeneration granulation production capacity

pet waste bottle regeneration treatment, currently there are two main methods that have been industrialized. One is the "physical regeneration method", that is, the melting granulation method is used to recover pet pellets, said Aizi Harding; One is the "chemical regeneration method", which recovers monomers through the cracking of pet. At present, the recycling of pet waste bottles in Shanghai and all over the country basically adopts the melting granulation method. For example, the solution of pet waste bottle is used for modification to produce varnish for enameled wire

pet waste bottle regeneration granulation basic process: pet waste bottle sorting and removing labels → crushing → alkali washing → rinsing → centrifugal dehydration → pre drying → extrusion granulation. The core equipment of extrusion granulation can be series exhaust extruder, single screw extruder or twin screw extruder. Pet waste bottle recycling enterprises can purchase pet waste bottle recycling granulation equipment from relevant domestic plastic machinery manufacturers; It can also be produced on the basis of general equipment such as crushers, centrifuges, extruders, etc., by the pet waste bottle recycling granulation enterprises themselves to design and build cleaning systems. The latter is easier to mount. At present, the production capacity of regeneration and granulation of pet waste bottles in Shanghai is estimated to be more than 100000 tons/year, which is far greater than the actual needs of processing the current pet waste bottles. Even if the production and application of PET bottles have further development, there is no problem in the production capacity of regeneration and granulation of pet waste bottles

the problem of waste water treatment needs to be solved.

the waste water produced in the regeneration and granulation process of pet waste bottles is basically not subject to standard purification treatment at present. Pet waste bottle recycling and granulation enterprises in Shanghai are basically small-scale enterprises, adopting physical regeneration methods. In the regeneration process, wastewater is generally discharged directly into the river. Although the environmental protection in Shanghai has been strengthened continuously, the treatment of waste water in the regeneration process of pet waste bottles has not seen a fundamental change. The change only lies in the transfer of the regeneration site of pet waste bottles from the suburbs to the outer suburbs and from the suburbs of Shanghai to the surrounding areas such as Jiangsu and Zhejiang

at least 3~5 tons of waste water will be generated for each ton of recycled PET pellets, and 300000~500000 tons of waste water will be generated for 100000 tons of recycled PET pellets every year. While recycling wastes and improving the environmental pollution caused by solid wastes, it also produces pollution to the water environment, which is a problem that needs to be paid close attention to. Therefore, it is a very urgent task for Shanghai and even the whole country to do a good job in the waste water treatment of pet waste bottle recycling granulation enterprises

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