Details

Autor(en) / Beteiligte

• Yang, Chao
• Fan, Yiang
• Shang, Shanshan
• Li, Pu
• Li, Xiao-yan

Titel

Fabrication of a permeable SnO2-Sb reactive anodic filter for high-efficiency electrochemical oxidation of antibiotics in wastewater

Ist Teil von

• Environment international, 2021-12, Vol.157, p.106827-106827, Article 106827

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2021

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• [Display omitted] •A novel freestanding and permeable SnO2-Sb anode was fabricated without Ti support.•The anode was operated as a reactive anodic filter (RAF) for ECO process.•The flow-through RAF exhibited a 12-fold increase in mass transfer rate constant.•The RAF achieved CIP degradation efficacy of 99% during 200 h of operation.•The RAF-based ECO process performed efficiently in actual wastewater treatment. Electrochemical oxidation (ECO) is an appealing technology for treating emerging organic pollutants in wastewater. However, the conventional flow-by ECO process is expensive with a low energy efficiency owing to the limitations of mass transport of contaminants to the limited surface area of the anode. In this study, a novel freestanding porous and permeable SnO2-Sb anode was fabricated by one-step sintering using micrometer-sized (NH4)2CO3 grains as the pore-forming agents. This permeable SnO2-Sb anode without Ti substrate functioned as a reactive anodic filter (RAF) in an ECO cell to treat wastewater containing ciprofloxacin (CIP). Forcing the wastewater through the porous RAF depth-wise improved the mass transport and vastly enlarged the electroactive surface area. Compared with the conventional flow-by configuration, the flow-through RAF exhibited a 12-fold increase in the mass transfer rate constant (60.7 × 10−6 m s−1) and a 5-fold increase in the CIP degradation rate constant (0.077 min−1). At a cell potential of 4.0 V, more than 92% of the CIP was degraded in a single-pass operation at a filtration flux of 54 L m−2 h−1 and a short retention time of 1.7 min through the RAF. The robustness and stability of the RAF were demonstrated by its remarkable CIP degradation efficacy of 99% during 200 h of operation. The mechanism of CIP degradation was examined using probe molecules and density functional theory calculations and found to be a combined effect of direct electron transfer and oxidation by generated radicals (OH and SO4−). The great potential of RAF in flow-through ECO was further validated by its effective removal (>92%) of various organic pollutants in actual municipal wastewater at a low energy consumption of 0.33 kWh m−3. The RAF-based ECO process thus provides an advanced environmental technology for the oxidation of toxic and recalcitrant organic pollutants in wastewater treatment.