TY - JOUR

T1 - Effect of Surface Contamination on Near-Infrared Spectra of Biodegradable Plastics

AU - Mhaddolkar, Namrata

AU - Koinig, Gerald

AU - Vollprecht, Daniel

AU - Astrup, Thomas Fruergaard

AU - Tischberger-Aldrian, Alexia

N1 - Publisher Copyright: © 2024 by the authors.

PY - 2024/8/6

Y1 - 2024/8/6

N2 - Proper waste sorting is crucial for biodegradable plastics (BDPs) recycling, whose global production is increasing dynamically. BDPs can be sorted using near-infrared (NIR) sorting, but little research is available about the effect of surface contamination on their NIR spectrum, which affects their sortability. As BDPs are often heavily contaminated with food waste, understanding the effect of surface contamination is necessary. This paper reports on a study on the influence of artificially induced surface contamination using food waste and contamination from packaging waste, biowaste, and residual waste on the BDP spectra. In artificially contaminated samples, the absorption bands (ADs) changed due to the presence of moisture (1352–1424 nm) and fatty acids (1223 nm). In real-world contaminated samples, biowaste samples were most affected by contamination followed by residual waste, both having altered ADs at 1352–1424 nm (moisture). The packaging waste-contaminated sample spectra closely followed those of clean and washed samples, with a change in the intensity of ADs. Accordingly, two approaches could be followed in sorting: (i) affected wavelength ranges could be omitted, or (ii) contaminated samples could be used for optimizing the NIR database. Thus, surface contamination affected the spectra, and knowing the wavelength ranges containing this effect could be used to optimize the NIR database and improve BDP sorting.

AB - Proper waste sorting is crucial for biodegradable plastics (BDPs) recycling, whose global production is increasing dynamically. BDPs can be sorted using near-infrared (NIR) sorting, but little research is available about the effect of surface contamination on their NIR spectrum, which affects their sortability. As BDPs are often heavily contaminated with food waste, understanding the effect of surface contamination is necessary. This paper reports on a study on the influence of artificially induced surface contamination using food waste and contamination from packaging waste, biowaste, and residual waste on the BDP spectra. In artificially contaminated samples, the absorption bands (ADs) changed due to the presence of moisture (1352–1424 nm) and fatty acids (1223 nm). In real-world contaminated samples, biowaste samples were most affected by contamination followed by residual waste, both having altered ADs at 1352–1424 nm (moisture). The packaging waste-contaminated sample spectra closely followed those of clean and washed samples, with a change in the intensity of ADs. Accordingly, two approaches could be followed in sorting: (i) affected wavelength ranges could be omitted, or (ii) contaminated samples could be used for optimizing the NIR database. Thus, surface contamination affected the spectra, and knowing the wavelength ranges containing this effect could be used to optimize the NIR database and improve BDP sorting.

KW - Biologisch abbaubare Kunststoffe,

KW - PLA

KW - Oberflächenkontamination

KW - NIR-Sortierung

KW - biodegradable plastics waste management

KW - effect on NIR spectrum

KW - near-infrared sorting

KW - polylactic acid

KW - surface contamination

KW - thermoplastic starch

UR - http://www.scopus.com/inward/record.url?scp=85202437591&partnerID=8YFLogxK

U2 - 10.3390/polym16162343

DO - 10.3390/polym16162343

M3 - Article

VL - 16.2024

JO - Polymers

JF - Polymers

SN - 2073-4360

IS - 16

M1 - 2343

ER -