摘要
Apparent aqueous removal overestimates net 4-NPs attenuation in textile dyeing wastewater treatment. • Stage-dependent NP rebound occurs via precursor transformation and interphase redistribution. • 4-NPs exhibit stage-dependent rebound due to precursor transformation and sludge-water redistribution. • Low-branched 4-NP isomers attenuate more readily than highly branched, persistent isomers. • Highly branched isomers enrich in final effluents and sludge, raising environmental concern. Nonylphenols (NPs) are ubiquitous endocrine disruptors in textile wastewater, yet their removal is typically evaluated using bulk concentrations, ignoring isomer-specific behaviors. To address this, we investigated eight textile dyeing treatment plants (TDPs) in the Pearl River Delta, using SPE–GC–MS to track the occurrence, attenuation, and sludge–water partitioning of ten major 4-NP isomers. Although apparent aqueous removal was high (61.1%–99.5%), NP concentrations did not decrease monotonically, instead showing a pattern of initial reduction, intermediate rebound, and final decline. Mass-balance analysis revealed wide variations in apparent net attenuation (−30.5% to 63.8%), indicating that simple aqueous removal does not guarantee actual biological degradation. Crucially, attenuation was highly isomer dependent. Low-branched 4-NP isomers showed stronger apparent attenuation during biological treatment, while highly branched isomers often became enriched in the final effluent. Additionally, sludge–water distribution coefficients (logKd) consistently decreased as side-chain complexity increased. Overall, these results suggest that the fate of 4-NPs in TDPs is strongly isomer-dependent and that reliance on bulk aqueous concentrations alone may not adequately represent the isomer-resolved fate and residual environmental implications of NPs in textile dyeing wastewater treatment systems. Download: Download high-res image (191KB) Download: Download full-size image
危险品化学品经营许可证（带存储）