Removal efficiency and emission flux of emerging contaminants from dyeing production activities

Dyeing wastewater is a significant source of industrial pollution, with emerging contaminants posing risks to aquatic ecosystems and human health, yet integrated assessments of multiple contaminant classes in dyeing wastewater at the enterprise scale remain scarce. This study investigated the occurrence, removal efficiency, and ecological risk of polyfluoroalkyl substances (PFAS), bisphenols (BPs), and phthalates (PAEs) in wastewater samplesfrom 18 dyeing enterprises in Guangdong Province, China. Detected concentrations ranged from 1.20 to 111 ng/L for PFAS, 10.5-1.98 × 10³ ng/L for BPs, and 15-3.27 × 10⁴ ng/L for PAEs, revealing significant inter-enterprise variability. Removal efficiencies varied substantially across enterprises, with some compounds exhibiting negative removal rates, indicating possible transformation, desorption, or process-induced release during treatment. Ecological risk assessment identified bisphenol A (BPA) and diethylhexyl phthalate (DEHP) as priority contaminants. Given the persistence and bioaccumulation potential of PFAS, additional risk assessment focused on fish collected near discharge points. While PFAS concentrations in some samples exceeded European Union regulatory thresholds, overall levels suggest limited short-term health risk, although potential long-term exposure remains a concern. Given its high concentration of dyeing enterprises and substantial wastewater discharge intensity, Guangdong represents a critical case for understanding dyeing wastewater impacts in China. The findings and solutions derived from this region are therefore not only locally relevant but also provide a valuable reference for dyeing industries across China.