Electrochemical decontamination of waters by advanced oxidation processes (AOPS): Case of the mineralization of 2,4,5-T on BDD electrode

In the present work, herbicide 2,4,5-trichlorophenoxyacetic acid, more commonly known as 2,4,5-T herbicide, has been completely mineralized (i.e. transformed into CO2 and H2O) in satd. aq. solns. using a semi-industrial electrochem. cell that contains a boron doped diamond anode and a zirconium cathode. We have performed cyclic voltammetry, chronoamperometry and bulk electrolysis to give the optimization characteristics of the degrdn. of such a compd. and its byproducts. Bulk electrolysis in the potential region of electrolyte decompn. leads to the complete destruction of 2,4,5-T and its degrdn. intermediates by means of the electrogeneration of the highly reactive hydroxyl radicals. The evolution of the COD and the instant current efficiency (ICE) during the degrdn. process is perfectly predicted by a theor. math. model. HPLC and GC-MS have also been performed to highlight the evolution of the mother product and its degrdn. intermediates. Kinetic anal. of the obtained results has shown a fast destruction of the mother herbicide asserting a diffusion-controlled process. 2,4,5-Trichlorophenol and quinone-based org. compds. have been depicted as arom. intermediates, all of them transformed into short chains carboxylic acids before complete mineralization happens. [on SciFinder (R)]