Pinaya Jhonny, Boiko Yuliia, Ismail Mohamed, Wahlberg Jan, Pyo Sang-Hyun, Vargas Virginia A, Hatti-Kaul Rajni
Centro de Biotecnología, Facultad de Ciencias y Tecnología, Universidad Mayor de San Simón, Cochabamba, Bolivia.
Division of Biotechnology and Applied Microbiology, Department of Process and Life Science Engineering, Kemicentrum, Lund University, Box 124, SE-221 00 Lund, Sweden.
Waste Manag. 2025 Aug 1;204:114913. doi: 10.1016/j.wasman.2025.114913. Epub 2025 Jun 4.
Plastic packaging provides enormous benefits for preservation and transportation of food and beverage products. However, recycling the multilayered packaging materials represents a challenge due to the complexity of separating the components making up the different layers. The drinks packaging, having aluminium (Al) as a light barrier placed between polyethylene layers inside the paperboard carton, comprises a significant category of post-consumer waste in need of complete recycling. Microbially produced organic acids are gaining attention for recovery of metals from industrial residues. This report presents a study on evaluation of acetic- and gluconic acid, which are known to be produced by acetic acid bacteria, for leaching out the Al from Tetra Pak PolyAl material remaining after removal of the paperboard. By using Taguchi design technique L (3), optimal conditions for 100 % Al leaching from 1 % (w/v) PolyAl (0.4 cm) were determined to be treatment at pH 1 and 50 °C with 0.25 M acetic acid for 6 days or 1 M gluconic acid for 15 days. Increasing the PolyAl concentration to 2 % w/v and particle size to 4 cm resulted in increase in the time for maximal Al leaching. Various microscopic, spectroscopic and thermal analyses techniques confirmed the removal of Al and revealed no notable change in the properties of the residual PE. The metal released was recovered nearly quantitatively (99.5 %) by precipitation as Al(OH) only from the acetic acid leachate. The results indicate the potential of the leaching method in providing a greener route for recycling the Al containing packaging material using biogenic organic acids.
塑料包装为食品和饮料产品的保存和运输带来了巨大益处。然而，由于构成不同层的成分分离复杂，回收多层包装材料面临挑战。饮料包装中，铝（Al）作为阻光层置于纸板箱内的聚乙烯层之间，是需要完全回收的一大类消费后废弃物。微生物产生的有机酸在从工业残渣中回收金属方面正受到关注。本报告介绍了一项关于评估乙酸和葡萄糖酸的研究，已知这两种酸由醋酸菌产生，用于从去除纸板后剩余的利乐宝PolyAl材料中浸出铝。通过使用田口设计技术L(3)，确定从1%（w/v）的PolyAl（0.4厘米）中100%浸出铝的最佳条件为：在pH 1和50°C下，用0.25 M乙酸处理6天或用1 M葡萄糖酸处理15天。将PolyAl浓度提高到2% w/v并将粒径增加到4厘米，导致最大铝浸出时间增加。各种微观、光谱和热分析技术证实了铝的去除，并表明残余聚乙烯的性能没有明显变化。仅从乙酸浸出液中通过沉淀为Al(OH)几乎定量地回收了释放的金属（99.5%）。结果表明，浸出法有可能为使用生物源有机酸回收含铝包装材料提供一条更环保的途径。
