Odor characterization along the recycling process of post-consumer plastic film fractions. (1st July 2020)

• Record Type: Journal Article
• Authors: Strangl, Miriam; Ortner, Eva; Fell, Tanja; Ginzinger, Tanja; Buettner, Andrea
• Is Part Of: Journal of cleaner production. Volume 260(2020)
• Publication Date: 2020-07-01
• Subjects: Gas chromatography -- LDPE -- Olfactometry -- Mass spectrometry -- Plastic -- Washing water; 2D-GC–MS/O two-dimensional gas chromatography–mass spectrometry/olfactometry -- cOEDA comparative odor extract dilution analysis -- FID flame ionization detector -- GC–O gas chromatography-olfactometry -- HDPE high-density polyethylene -- LDPE low-density polyethylene -- OD odor dilution -- ODP odor detection port -- PET polyethylene terephthalate -- PO polyolefin -- PP polypropylene -- PS polystyrene -- PVC polyvinylchloride; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2020.121104
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: For complying with the recently set higher EU recycling targets, the quality parameters of polyolefin recyclates need improvements to enter new sales markets. Consequently, the plastics recycling sector is increasingly confronted with higher demands on the sensory properties of recycled plastics from post-consumer packaging material. The objective of this study was to examine the sensory properties of two different post-consumer film fractions along a conventional recycling process by a combined sensory-analytical approach. Accordingly, sensory evaluations of two post-consumer film fractions, the associated washing water, a washed waste fraction and conventional recycled pellets thereof were performed by an expert panel, followed by the characterization of the underlying odorants by means of gas chromatography-olfactometry and (two-dimensional) gas chromatography-mass spectrometry/olfactometry. Using this targeted approach, in sum, more than 50 odorants were successfully identified along the processing chain. Most dominant was an array of typical metabolites formed by microorganisms such as cheesy smelling short chain carboxylic acids as well as sulphur or nitrogen containing odorants exhibiting, amongst others, garlic-like or fecal smells. Furthermore, two post-consumer film fractions sorted according to a defined geometry showed great similarities in the odor profiles as well as in the odorant composition. The negligible effect of the applied washing and the still high odor pollution of the recycled pellets demonstrate the urgent need for odor removal strategies in this field. Thereby, the chemical structures of the odorants obtained within this study provide key information on potential sources and formation pathways of odorants supporting the development of targeted deodorization methods. Highlights: No significant effect of the applied industrial washing process on the odor profile. Close odor similarity between the post-consumer film fractions no. 310 and 323. Carboxylic acids, sulphur and nitrogen containing odorants predominant in all samples. Several odorants are typical metabolic products of microorganism. Detection of an additional roasted coffee bean-like odor in the extruded pellets.