Oxidative degradation and mineralization of the phenylurea herbicide fluometuron in aqueous media by the electro-Fenton process

The degradation of the phenylurea herbicide fluometuron (FLM) was studied by the electro-Fenton (EF) process, using BDD and Pt as anodes and a carbon felt cathode. The influence of several parameters, such as the catalyst concentration, current intensity and type of anode, on the FLM degradation rate in aqueous acid medium by the EF process, was determinated. The evolution of the solution composition was followed by chromatographic analysis and the FLM mineralization as well as intermediates formed during the EF treatment were evaluated and the total organic carbon (TOC) measured. The mineralization percentage was found to depend on the current intensity and type of anode. A quasi-complete mineralization (more than 98%) as well as a low energy consumption (<10 kWh (g TOC)−1) was obtained with BDD anode. The absolute second-order rate constant for the FLM oxidation reaction was (4.44 ± 0.07) × 109 M−1 s−1. A tentative, complete mineralization reaction mechanism was also proposed.