In this work, the impact of organic matter on the degradation of polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge by ultrasound-Fenton process has been studied. Sludge organic matter (SOM) was characterized and the degradation efficiencies of PAHs at various oxidation intensities (Fenton’s reagent of 20, 70, and 140 mmol/L, ultrasonic densities of 0.36, 0.90, and 1.80 W/cm³, and reaction time of 15, 25, and 40 min) were determined. The results showed that 75.52-84.40% of PAHs and 16.32-31.13% of SOM had degraded after ultrasound-Fenton treatment, confirming the competitive relation between both of them for degradation. The aliphatic SOM fractions were preferentially oxidized owing to their easily degradable properties, while equimolar amounts of the aromatic moieties would require more oxidant compared to the aliphatic fractions. Correlation analysis demonstrated that SOM with its lower content, stronger polarity, and a higher proportion of labile organic fraction was more favourable for PAHs degradation. In addition, the SOM fractions were decomposed to biodegradable matter after treatment, which further enhance the biodegradability of sludge. This study provides insights into the role of SOM in PAHs removal by AOPs, and confirms that the ultrasound-Fenton treatment could not only effectively degrade PAHs, but also modify SOM.

中文翻译：

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超声波-Fenton工艺处理污泥：污泥有机物的表征及其对去除PAHs的影响

在这项工作中，研究了有机物对超声波-芬顿法降解纺织品染色污泥中多环芳烃（PAHs）的影响。对污泥有机物（SOM）进行了表征，并表征了PAHs在各种氧化强度下的降解效率（Fenton试剂为20、70和140 mmol / L，超声密度为0.36、0.90和1.80 W / cm ³，确定反应时间为15、25和40分钟。结果表明，超声-芬顿处理后，PAHs降解了75.52-84.40％，SOM降解了16.32-31.13％，证实了两者之间的竞争关系。脂族SOM馏分由于其易于降解的性质而被优先氧化，而等摩尔量的芳族部分与脂族馏分相比将需要更多的氧化剂。相关分析表明，SOM含量低，极性强，不稳定有机物比例较高，更有利于PAHs的降解。另外，处理后SOM馏分被分解为可生物降解的物质，这进一步提高了污泥的生物降解性。