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Perfluorinated compounds (PFCs) are considered as the most recalcitrant organic contaminants. Our previous research has shown that PFCs can be completely defluorinated in the UV/organoclay/3-indole acetic acid system, however, the factors that could affect the degradation of PFCs, are still not clear. In this study, we further investigated the effect of different indole derivatives and organo-modified montmorillonite on the degradation of perfluooctanoic acid (PFOA). Based on multiple linear regression analysis, our results clearly indicate that hydrated electron yields of indole derivatives, adsorption of PFOA and indole derivatives on organo-montmorillonite contributed independently to the degradation of PFOA. In addition, the results also show that the presence of humic substance (even at 10 mg C L −1 ) would not significantly suppress the degradation process due to the strong adsorption of humic substance on the organo-montmorillonite surface. This study would provide more information to design an efficient and environment-friendly system for degradation of PFCs, and this technique will have great potential for treatment of persistent contaminants under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Over the recent past, fluoroquinolone antibiotics (FQs) have raised extensive attention due to their potential to induce the formation of resistance genes and "superbugs", thus various advanced oxidation techniques have been developed to eliminate their release into the environment. In the present study, the prototype tetraamido macrocyclic ligand (Fe III -TAML)/hydrogen peroxide (H 2 O 2 ) system is employed to degrade FQs (i.e., norfloxacin and ciprofloxacin) over a wide pH range (i.e., pH 6-10), and the reaction rate increases with the increase in pH level. The effect of dosage of Fe III -TAML and H 2 O 2 on the degradation of FQs is evaluated, and the reaction rate is linearly correlated with the added amount of chemicals. Moreover, the impact of natural organic matters (NOM) on the removal of FQs is investigated, and the degradation kinetics show that both NOM type and experimental concentration exhibit negligible influence on the oxidative degradation of selected antibiotics. Based on the results of liquid chromatography-high resolution mass spectrometry and theoretical calculations, the reaction sites and pathways of FQs by Fe III -TAML/H 2 O 2 system are further predicted and elucidated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)