Degradation of 4-chlorophenol by BM Fe/Cu-O₂ system: The symbiosis of ⋅ O 2 − and ·OH radicals

• Published in: Water environment research 2019-08, Vol.91 (8), p.770-779
• Main Authors: Fan, Jinhong, Qin, Hehe, Zhang, Yunfei, Jiang, Simin
• Format: Article
• Language: English
• Subjects: RESEARCH ARTICLE
• ISSN: 1061-4303; 1554-7531
• DOI: 10.1002/wer.1107

In this study, Fe/Cu bimetal composite was prepared by high-energy ball milling (BM) method for the removal of refractory organics. The BM Fe/Cu bimetal was characterized by SEM-EDS, XRD, and XPS. Evenly distributed Fe and Cu was observed in the EDS mapping. In contrasting experiments, the removal rate of 4-chlorophenol (4-CP) by BM Fe/Cu materials was about 10-fold faster than that by chemical substitution deposition (CSD) of Fe/Cu material. Complete 4-CP removal and 66.7% of total organic carbon (TOC) mineralization in the BM Fe/Cu–O₂ system were achieved. Dissolved oxygen plays a crucial role for 4-CP degradation through the in situ generation of reactive oxygen species (ROS) such as H₂O₂, ·OH, and ⋅ O 2 − via oxygen activation reactions. The predominant reactive radicals were identified to be ⋅ O 2 − and ·OH through ESR technique and inhibition experiments. The coexistence of oxidation and reduction of 4-CP in the BM Fe/Cu-O₂ system was proposed.