Moreira Letícia Parada, Selinger Amanda, Sadauskas-Henrique Helen, Choueri Rodrigo Brasil, Gusso-Choueri Paloma Kachel, Pacheco Marcos Tadeu Tavares, Silveira Landulfo
Department of Ecotoxicology, Universidade Santa Cecília - UNISANTA, Santos, Brazil.
Laboratory of Marine and Coastal Organism Biology, Universidade Santa Cecília - UNISANTA, Santos, Brazil.
J Air Waste Manag Assoc. 2025 Sep;75(9):719-734. doi: 10.1080/10962247.2025.2513935. Epub 2025 Aug 8.
The identification of postconsumer plastic types is important for proper separation for recycling purposes. In this work, Raman spectroscopy was used as a tool to identify the type of postconsumer plastic and subsequent separation for applications in recycling stations and plants. The different postconsumer plastic samples were separated, and Raman spectra were obtained using a dispersive spectrometer (with an excitation wavelength of 830 nm, a laser power of up to 400 mW, an integration time of 3 s, and a spectral range between 400 and 1800 cm). The peaks in the spectra of each type of plastic were correlated with the literature, and the spectra were separated into groups according to their symbology. The spectra were subjected to group classification using partial least squares regression. The types of plastics were identified, and the spectra of the PE-HD and PE-LD plastics were similar because they had the same chemical structure. Peaks of the dyes commonly used in packaging and labels were also observed. The classification model achieved 100% accuracy in separating plastics from 1 to 6. Plastics of type 7 were not modeled due to their mixed composition. Raman spectroscopy can be a useful tool in the identification and separation of postconsumer plastics for proper recycling. This study demonstrates the potential of Raman spectroscopy as an effective and accurate tool for identifying and classifying postconsumer plastics, achieving 100% accuracy for plastics classified from types 1 to 6 according to the recycling triangles. The ability to differentiate plastic types, including the detection of dyes commonly used in packaging and labels, can significantly enhance sorting efficiency in recycling facilities. By improving plastic separation, this method can contribute to more sustainable recycling practices, reducing contamination in recycled materials and supporting the development of a circular economy.
识别消费后塑料的类型对于为回收目的进行正确分类至关重要。在这项工作中，拉曼光谱被用作一种工具，用于识别消费后塑料的类型，并随后在回收站和工厂进行分类以便应用。将不同的消费后塑料样品进行分离，并使用色散光谱仪获得拉曼光谱（激发波长为830nm，激光功率高达400mW，积分时间为3s，光谱范围在400至1800cm之间）。每种塑料类型光谱中的峰与文献进行关联，并根据其符号学将光谱分为不同组。使用偏最小二乘回归对光谱进行组分类。确定了塑料的类型，高密度聚乙烯（PE - HD）和低密度聚乙烯（PE - LD）塑料的光谱相似，因为它们具有相同的化学结构。还观察到了包装和标签中常用染料的峰。该分类模型在将塑料从1类分离到6类时准确率达到100%。7类塑料由于其混合成分未进行建模。拉曼光谱可成为识别和分离消费后塑料以进行适当回收的有用工具。本研究证明了拉曼光谱作为一种有效且准确的工具用于识别和分类消费后塑料的潜力，根据回收三角对1至6类塑料的分类准确率达到100%。区分塑料类型的能力，包括检测包装和标签中常用的染料，可显著提高回收设施中的分拣效率。通过改进塑料分离，这种方法有助于实现更可持续的回收实践，减少回收材料中的污染，并支持循环经济的发展。
