Unlocking Value: Compositional Analysis of Post-Consumer Textile Waste in the Residual Fraction in Catalonia and Its Recycling Potential

The growing volume of textile waste discarded in the general rest fraction presents a critical challenge to achieving a circular economy. This study provides a comprehensive material characterization of 382.7 kg of textile waste, comprising 1682 individual pieces collected from general waste containers in Catalonia, Spain, with the aim of assessing their potential for high-value recycling. The analysis confirmed this stream consists predominantly of post-consumer textiles (97.3%). Its relevance lies in its composition: mono-component items dominate (54.0% by weight), mainly composed of cotton (51.6%) and polyester (28.4%). This prevalence of mono-material items suggests a substantial, and currently underestimated, volume of recoverable resources and confirms a high recycling potential. However, the study also identifies major challenges for the recovery of this waste stream. On the one hand, it exhibits a high degree of contamination, both in terms of moisture, dirtiness and non-textile disruptors (48.0% by weight), which increases the cost and complexity to the recycling workflow and directly impacts its current viability. On the other hand, the quantitative composition determined by Near-Infrared (NIR) spectroscopy agreed with the ISO 1833 standard in only 37.9% of cases, critically exposing the technological limitations of current automated techniques for quantitative analysis in textiles made of fiber blends. Despite these limitations, the findings are highly relevant for guiding strategic investments in infrastructure, technology, and policy to unlock the full potential of this high-volume waste as a resource.