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Recycled polyester textile fibers stemming from waste polyester material have been applied in the textile industry in recent years. However, there are few studies focusing on the evaluation and comparison of the environmental impacts caused by the production of virgin polyester textiles and recycled polyester textiles. In this study, the carbon footprint and water footprint of virgin polyester textiles and recycled polyester textiles were calculated and compared. The results showed that the carbon footprint of the virgin polyester textiles production was 119.59 kgCO2/100 kg. Terephthalic acid production process occupied the largest proportion, accounting for 45.83%, followed by polyester fabric production process, ethylene production process, paraxylene production process, ethylene glycol production process and polyester fiber production process. The total carbon footprint of waste polyester recycling was 1154.15 kgCO2/100 kg, approximately ten times that of virgin polyester textiles production. As for the water footprint, it showed that virgin polyester fabric production and recycled polyester fabric production both had great impact on water eutrophication and water scarcity. Chemical oxygen demand caused the largest water eutrophication footprint, followed by ammonia-nitrogen and five-day biochemical oxygen demand. The water scarcity footprint of virgin polyester fabric production and recycled polyester fabric production was 5.98 m3 H2Oeq/100 kg and 1.90 m3 H2Oeq/100 kg, respectively. The comprehensive evaluation of carbon footprint and water footprint with the life cycle assessment polygon method indicated that the polyester fabric production process exhibited greater environmental impacts both for virgin polyester and recycled polyester.

Given the serious problems of climate change, water shortage and water pollution, researchers have paid increasing attention to the concepts of the carbon footprint and water footprint as useful indices to quantify and evaluate the environmental impacts of the textile industry. In this study, assessment of the carbon footprints and water footprints of ten kinds of cashmere fabrics was conducted based on the PAS 2050 specification, the Water Footprint Network approach and the ISO 14046 standard. The results showed that knitted cashmere fabrics had a greater carbon footprint than woven cashmere fabrics. Contrarily, woven cashmere fabrics had a greater water footprint than knitted cashmere fabrics. The blue water footprint, grey water footprint and water scarcity footprint of combed sliver dyed woven cashmere fabric were the largest among the ten kinds of cashmere fabrics. The main pollutants that caused the grey water footprints of cashmere fabrics were total phosphorus (TP), chlorine dioxide, hexavalent chromium (Cr (VI)) and sulfide. The leading contributors to the water eutrophication footprint were total nitrogen, ammonia nitrogen, chemical oxygen demand and TP. These typical pollutants contributed 39% ~ 48%, 23% ~ 28%, 12% ~ 24% and 12% ~ 14% to each cashmere product’s water eutrophication footprint, respectively. The leading contributors to the water ecotoxicity footprint were aniline, Cr (VI) and absorbable organic halogens discharged in the dyeing and finishing process.

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The chemical pollutants discharged in the production processes of textile products cause severe impact on the environment. The chemical footprint (ChF) methodology provides a new way to quantify the toxicity impacts caused by chemical pollutants. ChF does well in identifying priority chemical pollutants and helping enterprises to select greener chemicals to reduce the environment impacts. In this study, the ChF of woollen yarn were assessed with the data that collected from the production processes. The results showed that the ChF of dyeing process (4.10E+06 l) accounted for the largest proportion, because a large number of auxiliaries were used in the dyeing process to prevent uneven dyeing and colour difference, followed by scouring (7.79E+05 l) and finishing (8.11E+03 l). Among all the discharged chemical pollutants, polyoxyethylene nonyl phenyl ether (1.37E+06 l) caused the most ecotoxicity severe impact on the environment due to its high bioaccumulation and high toxicity to ecosystem, followed by sulfuric acid (1.03E+06 l). Sodium chloride and hydrogen peroxide were the two substances that caused the least environmental load. The overall uncertainty caused by toxicity prediction data accounting for 20.2% of the total ChF, and the uncertainty of the scouring process was the most. The results are referable for wool textiles producers to enhance the textile chemicals management.