Electrochemical Abatement of Atrazine Solutions Using an Undivided Stirred Tank Cell with Pt or BDD Anode

Abstract

<p>Nowadays, the increasing pollution of natural water effluents with herbicides, such as atrazine (ATZ, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine), is an emerging problem that has not received the sufficient attention.  This work presents a study on ATZ degradation under an electrochemical advanced oxidation process (EAOP), such as anodic oxidation (AO).  The degradation of 175 mL of 10 and 40 mg L^-1 ATZ solutions was studied using Pt or BDD as anode. The assays were made with a stirred tank cell, using a supporting electrolyte of 0.050 mM of Na₂SO₄ at pH 3.0 by applying 0.18, 0.27 and 0.37 A cm^-2. The degradation rate increased by increasing current density, regardless of the anode employed. Greater amounts of ATZ were removed at higher organic load. The pesticide decay always obeyed a pseudo-first-order kinetics. A high degradation efficiency of 97%-99% was obtained by the more powerful AO-BDD process at 0.37 A cm^-2. High performance liquid chromatography (HPLC) was used to follow the evolution of major oxidation products by AO-BDD, such as desethyl atrazine, desethyl desisopropyl atrazine and cyanuric acid.</p>