Improvements in the electrochemically assisted absorption of BTX with the application of ultrasound

Abstract

In this work, it is evaluated the influence of the application of ultrasound (US) on the absorption and electrochemically assisted absorption of gaseous streams polluted with benzene, toluene, and xylene (BTX). The experimental device combines a jet mixer absorber and a single-compartment electrochemical flow cell equipped with boron-doped diamond (BDD) anode. Results show that application of US has a positive effect on the amount of the pollutants absorbed and oxidized. This is explained in terms of the promotion in the mass transfer processes and because of the activation of oxidising species. Intermediates produced in the oxidative degradation of BTX were principally carboxylic acids. When current density increases, the removal rate increases. However, the elimination efficiency (mmol A−1 h−1) and the synergy coefficient decrease. A simple model is formulated and applied, and it reproduced satisfactorily experimental results and help to understand the processes involved.