How low-value recyclables can be turned into waste
"You see, this is the third time I've made an appointment for door-to-door recycling, and I've got almost 40 yuan in environmental protection rewards. Recently, Aunt Zhang, who lives in Xinhualian Home Community, Yangzhuang Street, Shijingshan District, Beijing, made an appointment for the street "one-bag" door-to-door recycling service through the WeChat applet, which not only solved the problem of "waste items occupy too much space" without leaving home, but also received environmental protection incentives, which is really a lot of money.
"Used clothes, cardboard, glass bottles...... These ubiquitous wastes are low-value recyclables, and if they can be recycled, they can be turned into treasures, which will help to promote waste classification and reduction, resource recycling, and increase recycling rates. The staff who came to the door to collect were busy cleaning up and explaining at the same time.
According to professional explanations, low-value recyclables are the opposite of high-value wastes such as scrapped cars and waste household appliances, and their recycling is an important part of promoting the conservation and intensive utilization of various resources. So why recycle when it's low-value?
The recovery rate of low-value recyclables needs to be improved
Low-value recyclables are all kinds of waste that are recyclable, but their recycling requires high costs, and it is difficult to effectively recycle by relying solely on market forces. Such as common disposable lunch boxes, disposable plastic cups, styrofoam, waste plastic packaging bags, waste beverage paper-based composite packaging, waste paper cups and bowls, waste textiles, waste glass, etc.
At present, most of the low-value recyclables in China are mixed with domestic waste for collection, transportation, incineration or landfill. Among them, the average operating cost of incineration power generation construction is about 350 yuan/ton, which not only brings environmental pollution and increases carbon dioxide emissions, but also brings a continuous burden to local finances. A small part of low-value recyclables can enter the recycling system of renewable resources through the recycling behavior of enterprises or individuals. However, due to the poor recycling efficiency of low-value recyclables and the generally low level of technical equipment of enterprises, it has become a concentrated flashpoint of "small scattered pollution" and a shortcoming of the waste recycling system.
"Local governments do not pay attention to it, the enthusiasm of enterprises to recycle is not high, and the people's awareness of classification is indifferent, which is also the reason for the generally low recycling rate of low-value recyclables. Zhang Deyuan, director of the Circular Economy Research Office of the Institute of Economic System and Management of the Macroeconomic Research Institute of the National Development and Reform Commission, said that the "Research Report on the Recycling of Low-value Recyclables in China" released by the Institute in 2023 shows that in 2021, the production of various low-value recyclables in China will be about 95.77 million tons, and the recycling volume will be about 25.47 million tons, with a total recovery rate of only about 26.6%, which is far lower than the average recycling rate of more than 75% of major renewable resources.
In 2022, China's main renewable resources will be recycled and recycled more than 371 million tons, of which scrap steel, waste paper, scrap copper, and scrap lead account for 22%, 54%, 35%, and 47% of the output of steel, paper, copper, and lead, respectively, and renewable resources have become an important source of resources. "If the recovery rate of low-value recyclables is increased to 50%, 47.9 million tons of low-value recyclables can be recycled every year, and more than 45 million tons of renewable resources such as recycled plastics and recycled paper will be added to the society, of which about 60 million tons of crude oil will be saved by recycled plastics, which is equivalent to rebuilding a 'Daqing Oilfield'. Zhang Deyuan said that this is of great significance to ensure the security of China's industrial chain and supply chain.
It is worth noting that compared with the disposal of landfill or incineration of domestic waste, the carbon emission reduction effect of low-value recyclables is very obvious. For example, recycling 1 ton of waste plastic can reduce carbon emissions by 1.5~2.2 tons, which is equivalent to the carbon emissions of 700~750 liters of unleaded gasoline or diesel combustion.
With the improvement of mass consumption level and the high development of emerging industries such as e-commerce and takeaway, the total amount of municipal solid waste in China has been increasing. Relevant studies show that it is estimated that by 2030, China's urban garbage removal and transportation volume will reach 421~491 million tons/year. If 40% of domestic waste is recycled, it can reduce the comprehensive social cost of cleaning and transportation by 1184.84 yuan/ton, and at the same time, it can also reduce a large number of [~symbol~] British and carbon dioxide, and effectively improve the comprehensive economic, social and environmental benefits.
The establishment of a recycling system for waste materials is the key
Low-value recyclables come from all aspects of daily production and life, covering a wide range of varieties, diverse physical forms and different chemical properties. How to build a recycling operation system with effective upstream and downstream linkage, garbage classification, transportation and resource utilization has become the key to the recycling of low-value recyclables.
At the low-value recyclables sorting center in Haicang District, Xiamen City, Fujian Province, domestic waste mixed with low-value recyclables enters the intelligent sorting platform after breaking bags, sanitizing, screening and other processes, waiting for "identification".
"Intelligent sorting mainly uses spectral recognition, AI and other technologies for accurate classification, and the classification and recognition rate exceeds 95%. Cai Liangzhi, general manager of the sorting center, introduced that different materials present different spectrums, and through near-infrared irradiation, preliminary material sorting can be achieved for low-value recyclables, and combined with AI technology, the category of materials can be accurately identified.
"After cleaning and sorting, this waste will become raw materials for production, which is a sweet spot in the eyes of many companies. Cai Liangzhi said that the sorted materials are refined into 15 categories such as ordinary paper and paper-plastic composite through robots for quality control and purity, and then sent to downstream recycling enterprises, and then "incarnated" into fabrics, shopping bags, plastic desks and chairs and other products.
When the mid-end intelligent sorting and end-end resource utilization are fully prepared, how to solve the front-end low-value recyclables sorting and recycling work?
In January 2022, the National Development and Reform Commission, the Ministry of Housing and Urban-Rural Development and other 7 departments jointly issued the "Guiding Opinions on Accelerating the Construction of a Waste Materials Recycling System", sounding the clarion call for the establishment of a waste materials recycling network system.
As one of the earliest cities in China to start implementing garbage classification, Hangzhou, Zhejiang Province, relying on the advantages of the digital economy, promotes the application of digital intelligence models such as "Internet +" in the construction of the waste materials recycling system, innovates the supervision mode of waste materials recycling, and promotes the reengineering of the recycling process and the reshaping of the system.
After years of efforts, Xiamen has initially explored a low-value recyclables recycling model covering the front, middle and back ends, which is "government overall deployment support, professional operation of enterprises, and active participation of residents". According to the operation data, the comprehensive separation rate of low-value recyclables in Xiamen has increased from 72.72% in 2020 to 74.31% in 2022, which can turn 150,000 tons of garbage into resources every year, with an economic value of more than 135 million yuan and reduce about 435,000 tons of carbon dioxide emissions.
Chongqing has made it clear that by 2025, the city will basically establish a complete recycling system for waste materials, and the processing and utilization of renewable resources will reach 16 million tons.
Shanghai proposes that by 2025, the city's domestic waste incineration capacity will be stabilized at 28,000 tons/day, and the wet waste treatment capacity will reach 11,000 tons/day, so as to fully guarantee the needs of domestic waste classification and resource utilization.
Retrofitting a technology engine for high-value utilization
At present, takeaway has penetrated into all aspects of contemporary life. According to industry statistics, more than 1 million tons of takeaway lunch boxes are used in China every year. When you are feasting, have you ever cared about the ultimate fate of these waste lunch boxes?
"We have solved the technical problems in the removal of impurities, deodorization, spinning and fabric production of recycled lunch box materials, and successfully opened up the technical route of 'recycled lunch box - slicing - granulation - drawing - weaving - clothes'. Li Bin, a researcher at the polymer carbon neutrality platform of the Advanced Low-dimensional Materials Center of Southeast University, introduced that they have joined forces with many upstream and downstream enterprises and research institutions to creatively process and modify waste lunch boxes into ultra-fine denier polypropylene fibers, and made fabrics and T-shirts with quick-drying functions.
Scientific and technological progress is the key to solving environmental problems. At present, some textile enterprises use the leftovers and printing and dyeing defective fabrics produced in the production process to recycle, and develop home textile household products such as carpets, bedding, storage boxes, etc., and some enterprises use pesticide packaging waste to develop products such as seedling throwing trays, packing belts, and engineering plastic barrels.
In Licang District, Qingdao City, Shandong Province, smart recycling equipment is changing residents' recyclable habits and shaping a new fashion of green and healthy life.
"There is no need for sorting, the machine will automatically identify whether it is recyclable, and after a one-time delivery, it can be automatically weighed and a cash reward can be obtained. Zhu Haiyan, a resident of Jinqiu Community, Hushan Street, Licang District, said that smart recycling is good for residents' families and promoting garbage sorting, and everyone is highly motivated to participate.
Not only that, the intelligent recycling equipment can also connect the transportation platform through the Internet of Things, and through the big data operation platform, intelligently plan the cleaning route, greatly shorten the waiting time for full warehouse, and residents can inquire about the service status of each equipment at any time and reasonably arrange the delivery time.
Nowadays, the "high-value" application of many low-value recyclables has formed a "negative pressure" in the industrial chain, which is attracting more scientific and technological forces to help low-value recyclables turn waste into treasure.
