Chemical Engineering Department, University of Alicante, P.O. Box 99, 03080 Alicante, Spain.
Chemosphere. 2011 Oct;85(3):516-24. doi: 10.1016/j.chemosphere.2011.08.013. Epub 2011 Sep 8.
The increase in electronic waste, including cellular telephones, worldwide is a worrying reality. For this reason, urgent action on the management of these wastes is necessary within a framework that respects the environment and human health. Mobile phone components can be physically segregated through grinding at the dismantling sites, in order to reuse or reprocess (via chemical or physical recycling) the recovered plastics and valuable metals. A kinetic study of the thermal decomposition of a mobile phone case has been carried out under different conditions by thermogravimetry. Several experiments were performed in a nitrogen atmosphere (pyrolysis runs) and also in an oxidative atmosphere with two different oxygen concentrations (10% and 20% oxygen in nitrogen). Dynamic runs and dynamic+isothermal runs have been carried out to obtain much decomposition data under different operating conditions. Moreover some TG-MS runs were performed in order to better understand the thermal decomposition of a mobile phone case and identify some compounds emitted during the controlled heating of this material. A scheme of two independent reactions for pseudocomponents has been proposed for the pyrolysis process. For the combustion runs, the scheme proposed includes two pyrolytic reactions competing with other two reactions with formation of an intermediate residue, and finally the reaction of oxidation/burning of the intermediate residue. Furthermore, pyrolysis and combustion runs at 500 °C in a horizontal laboratory furnace were carried out. More than 50 compounds, including carbon oxides, light hydrocarbons, and polycyclic aromatic hydrocarbons (PAHs) have been identified and quantified. The main semivolatile compounds detected were phenol and styrene. Furthermore, polychlorodibenzo-p-dioxin and polychlorodibenzofurans (PCDD/Fs) and dioxin-like PCBs produced were analyzed. In the combustion run, PCDDs were obtained in higher amounts than PCDFs and HxCDD was the most emitted homologue.
全球电子垃圾（包括手机）的增加是一个令人担忧的现实。出于这个原因，有必要在尊重环境和人类健康的框架内，对这些废物进行紧急管理。在拆解现场，通过粉碎可以将手机组件进行物理分离，以便对回收的塑料和有价值的金属进行再利用或再加工（通过化学或物理回收）。通过热重分析在不同条件下对手机外壳的热分解进行了动力学研究。在氮气气氛下（热解运行）进行了几项实验，并且在两种不同氧气浓度（氮气中的 10%和 20%氧气）的氧化气氛下进行了实验。进行了动态运行和动态+等温运行，以便在不同的操作条件下获得更多的分解数据。此外，还进行了一些 TG-MS 运行，以便更好地了解手机外壳的热分解情况，并识别在对这种材料进行受控加热过程中排放的一些化合物。为热解过程提出了两个独立的拟组分反应的方案。对于燃烧运行，所提出的方案包括两个热解反应，它们与形成中间残留物的其他两个反应竞争，最后是中间残留物的氧化/燃烧反应。此外，在水平实验室炉中在 500°C 下进行了热解和燃烧运行。鉴定和定量了 50 多种化合物，包括碳氧化物、轻烃和多环芳烃（PAHs）。检测到的主要半挥发性化合物是苯酚和苯乙烯。此外，还分析了多氯二苯并对二恶英和多氯二苯并呋喃（PCDD/Fs）以及产生的类似二恶英的 PCB。在燃烧运行中，PCDD 的产量高于 PCDF，并且 HxCDD 是排放量最大的同源物。
