Insights of ibuprofen electro-oxidation on metal-oxide-coated Ti anodes: Kinetics, energy consumption and reaction mechanisms. (November 2016)

• Record Type: Journal Article
• Authors: Wang, Chong; Yu, Yanxin; Yin, Lifeng; Niu, Junfeng; Hou, Li-An
• Is Part Of: Chemosphere. Volume 163(2016)
• Page Start: 584
• Page End: 591
• Publication Date: 2016-11
• Subjects: Ibuprofen -- Electrochemical oxidation -- Electrodes -- Energy cost -- Mineralization -- Mechanisms; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.08.057
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Electrochemical degradation of ibuprofen (IBP) was performed on three types of Ti-based metal oxide electrodes. The degradation of IBP followed pseudo-first-order kinetics and the electrochemical degradation rate constant ( k ) over Ti/SnO2 -Sb/Ce-PbO2 (9.4 × 10 −2 min −1 ) was 2.0 and 1.7 times of the values over Ti/Ce-PbO2 (4.7 × 10 −2 min −1 ) and Ti/SnO2 -Sb (5.6 × 10 −2 min −1 ), respectively. The removal of total organic carbon and the energy consumption per order for IBP degradation were 93.2% and 13.1 Wh L −1, respectively, under the optimal conditions using Ti/SnO2 -Sb/Ce-PbO2 anode. Six aromatic intermediate products of IBP were identified by ultra-high-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer. The electrochemical mineralization mechanism of IBP was proposed. It was supposed that OH radicals produced on the surface of anode attacked IBP to form hydroxylated IBP derivatives that were then followed by a series of hydroxylation, loss of isopropanol and isopropyl, decarboxylation and benzene ring cleavage processes to form simple linear carboxylic acids. By successive hydroxylation, these carboxylic acids were then oxidized to CO2 and H2 O, achieving the complete mineralization of IBP. Graphical abstract: Highlights: Electrochemical degradation of ibuprofen (IBP) was investigated. The degradation efficiency was governed by applied current and plate distance. The economic feasibility was evaluated by energy consumption per order ( E EO ). The electrochemical mineralization mechanism of IBP was proposed.