Wang Xinglei, Tang Simeng, Ding Ling, Qiu Xinran, Zhang Zhenming, Xu Li, Liang Xujun, Huang Xianfei, Guo Xuetao
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling 712100, China.
J Hazard Mater. 2024 Dec 5;480:135977. doi: 10.1016/j.jhazmat.2024.135977. Epub 2024 Sep 26.
The combustion of plastic waste releases volatile organic compounds (VOCs) that are harmful to human health. However, information on the micro-mechanisms of VOC formation remains lacking. Here, the study hypothesized and verified the relationship between VOC formation and solid component degradation during plastics combustion. The VOCs released during plastics combustion exhibit characteristics such as low carbon content (n< 10), volatility (9 μg m < logC < 11 μg m), and medium oxidation degree (-1.5 < OS¯ < -0.5). The dominant VOCs ketones/aldehydes/acids (33-43 %) may be attributed to the depolymerization of the polymer structure of plastics, the oxidation of C-O/CO groups, and the secondary cleavage of gaseous oxygen-containing macromolecules. The VOCs released from the combustion of polyethylene terephthalate (PET) and poly(butyleneadipate-co-terephthalate) (PBAT) contained more aromatics than polyethylene (PE) and polypropylene (PP). And the temperature response of aromatics released from PET and PBAT lagged other VOCs compared that of PP and PE. However, compared to biomass thermal conversion, combustion of plastics releases fewer aromatics and nitrogenous compounds. Collectively, this work shows that the formation mechanisms of VOCs contributed by the solid components during plastic combustion are similar for PET and PBAT due to their similar chemical structures. The proposed mechanism in this paper will provide insight into the control of contaminants during plastic combustion.
塑料废物的燃烧会释放对人体健康有害的挥发性有机化合物（VOCs）。然而，关于VOC形成的微观机制的信息仍然缺乏。在此，该研究假设并验证了塑料燃烧过程中VOC形成与固体成分降解之间的关系。塑料燃烧过程中释放的VOCs具有低碳含量（n<10）、挥发性（9μg m<logC<11μg m）和中等氧化程度（-1.5<OS¯<-0.5）等特征。占主导地位的VOCs酮/醛/酸（33-43%）可能归因于塑料聚合物结构的解聚、C-O/CO基团的氧化以及气态含氧大分子的二次裂解。聚对苯二甲酸乙二酯（PET）和聚（己二酸丁二醇酯-co-对苯二甲酸酯）（PBAT）燃烧释放的VOCs比聚乙烯（PE）和聚丙烯（PP）含有更多的芳烃。并且与PP和PE相比，PET和PBAT释放的芳烃的温度响应滞后于其他VOCs。然而，与生物质热转化相比，塑料燃烧释放的芳烃和含氮化合物较少。总的来说，这项工作表明，由于PET和PBAT的化学结构相似，它们在塑料燃烧过程中由固体成分贡献的VOCs形成机制相似。本文提出的机制将为塑料燃烧过程中的污染物控制提供见解。
