Dyeing sludge carbons activated by alkali-etching for outperformed 4-chlorophenol degradation in electro-Fenton process. (October 2022)

• Record Type: Journal Article
• Authors: Shen, Jian; Wu, Yahui; Yang, Yaohua; Zhou, Qiongzhi; Liu, Xiang; Wei, Tianxiang; Yu, Xinyi; Yu, Yifei; Li, Haitao; Fang, Tian
• Is Part Of: Journal of water process engineering. Volume 49(2022)
• Publication Date: 2022-10
• Subjects: Dyeing based sludge carbon -- Alkali activation -- Oxygen reduction reaction -- Electro-Fenton -- 4-Chlorophenol degradation; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2022.103103
• Languages: English
• ISSNs: 2214-7144

Abstract

Abstract: Developing outperformed and cost-effective heterogenous electro-Fenton catalysts will be necessary for halogen-containing compounds removal. In this contribution, dyeing based sludge carbons are activated via alkali etching to achieve extremely high removal of 4-Chlorophenols (4-CPs) in electro-Fenton process, fabricating robust and inexpensive catalysts via solid waste resources. The sludge carbons are initially activated by KOH etching and the corresponding structural and morphological features are characterized by p XRD, Raman, FT-IR, BET, and SEM. Further mechanism investigation is conducted via Rotating Ring-disc Electrode (RRDE) and EPR by confirming in-situ oxygen reduction pathway and the type of free radicals. The outcomes of this contribution suggest that the increment of alkali activation level facilitates oxygen reduction towards two-electrons transfer pathway with extremely high H2 O2 yield (81.32 %). Meanwhile, the removal rate and mineralization efficiency of 4-CP achieves 100 % and 62.14 %, respectively after reaction time with 150 min. Additionally, the high activated sludge carbons showcase extraordinary stability: H2 O2 yield and 4-chlorophenol removal present no obvious decay even enduring five cycles. Thus, alkali-etched dyeing sludge carbons not only provide outperformed, economic, and robust heterogenous electro-Fenton catalysts to remove halogen-containing compounds, but also benefit for solid waste reutilization. Highlights: Alkali-etching methodology benefits for activation and reuse of carbons from dye sludge. Alkali-etched‑carbons from dye sludge serve as outperformed electrocatalysts for 4-CPs removal. H2 O2 yield of alkali-etched‑carbons achieves 81.32 % in E-Fenton process. 4-CPs removal of alkali-etching‑carbons achieves almost 100 % with ultrahigh stability in E-Fenton process.