Reference News, July 31 report: According to the website of Popular Science magazine in the United States on July 23, engineers have recently developed a method to extract beneficial substances from cigarette butts. Their research results were published in the journal "Construction and Building Materials." The study shows that cigarette filters can significantly enhance the strength of recycled asphalt.
Although cigarette butts are small, their cumulative quantity is astonishing. The World Health Organization estimates that smokers discard approximately 450 billion filters annually. Recent forecasts suggest that by the end of 2025, this number may rise to 900 billion. This type of waste degrades very slowly, causing serious environmental problems in densely populated areas of the world, as well as causing significant damage to forests, waterways, and oceans.
In recent years, engineers have begun adding cellulose fibers (similar to materials in cigarette butts) and other additives to recycled asphalt mixtures (RAP). This process helps improve the strength and adhesion of recycled asphalt, allowing it to be reused for road paving. Given the huge potential of cigarette butts, researchers from the University of Granada in Spain and the University of Bologna in Italy decided to collaborate to find new methods to extract more practical applications from discarded cigarette butts.
The researchers first removed the residual organic matter from the cigarette butts, then crushed the remaining filters (which usually contain polylactic acid plastic and cellulose fibers), mixed them with a binding wax, and then processed them through pressing, heating, and cold cutting to produce two types of granules. Type 1 granules consist solely of cigarette butts, while Type 2 granules contain cigarette butt material and an additional recycled agent.
During the manufacturing process, when the granules come into contact with asphalt, a hot and viscous petroleum substance, the wax in the granules begins to melt. After melting, the plastic and cellulose fibers from the recycled cigarette butts integrate into the asphalt material, increasing its strength by improving flexibility and crack resistance.
Subsequently, researchers at the Department of Civil Engineering Laboratory at the University of Granada evaluated three types of asphalt mixtures. These mixtures contained 40% RAP and different proportions of granules. They used an asphalt without RAP as a control.
The research team found that each asphalt containing cigarette filters was more resilient than traditional asphalt. In addition, the addition of wax made it easier to adjust the viscosity of the asphalt. This can reduce the required manufacturing temperature, thereby reducing energy consumption and pollutant emissions.
The team also said that future research could focus on further optimizing the manufacturing process of fiber granules or increasing the amount of recycled agents to enhance the resilience of the asphalt. They also believe that combining other recycled materials with cigarette filters may further optimize the performance of asphalt materials, making the development of related industries more sustainable. (Translated by Zhu Jie)
Original article: https://www.toutiao.com/article/7533155461907710505/
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