| Abstrakt: |
Electrochemical oxidation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) over metal-oxide-coated Ti anodes, i.e., Ti/SnO 2 –Sb/Ce–PbO 2 , Ti/SnO 2 –Sb and Ti/RuO 2 , was examined. The degradation efficiency of over 90% was attained at 20 min at different initial concentrations (0.5–20 mg L −1 ) and initial pH values (3.1–11.2). The degradation efficiencies of 2,4,5-T on Ti/SnO 2 –Sb/Ce–PbO 2 , Ti/SnO 2 –Sb and Ti/RuO 2 anodes were higher than 99.9%, 97.2% and 91.5% at 30 min, respectively, and the respective total organic carbon removal ratios were 65.7%, 54.6% and 37.2%. The electrochemical degradation of 2,4,5-T in aqueous solution followed pseudo-first-order kinetics. The compounds, i.e., 2,5-dichlorohydroquinone and 2,5-dihydroxy- p -benzoquinone, have been identified as the main aromatic intermediates by liquid chromatography-mass spectrometry. The results showed that the energy efficiencies of 2,4,5-T (20 mg L −1 ) degradation with Ti/SnO 2 –Sb/Ce–PbO 2 anode at the optimal current densities from 2 to 16 mA cm −2 ranged from 8.21 to 18.73 kW h m −3 . [ABSTRACT FROM AUTHOR] |
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