Experimental and CFD simulation of glyphosate removal by a filter-press electrocoagulation reactor

Abstract

The present communication proposes a lumped kinetic and phenomenological model for glyphosate removal in synthetic agro-industrial wastewater using an electrocoagulation process (EC). A traditional filter press-cell electrochemical reactor is used for the EC experimental process. The outcomes of the current density, electrode material, and electrolysis process time were analyzed. The experimental results evidence a better removal performance for the aluminum than the carbon steel, and stationary removal conditions were reached at 40 min with a removal efficiency > 40% considering an input flow of 2 L min−1 and operational cost of 0.172 USD m−3 at 7.5 mA cm−2. The XRD analysis evidenced the interaction between the aluminum ion and the pesticide. The residual aluminum in the supernatant was < 10 mg L−1 at stationary removal conditions. The species distribution inside the reactor is described by the theoretical analysis, which takes into account the simultaneous solution of the Reynolds averaged Navier-Stokes (RANS) and kinetic-based mass conservation equation. Under full electrokinetic control (secondary current distribution), the electrode kinetics characterizing the flux generation of Al3+ on the anode is also taken into consideration. The model proposed here can explain the experimental COD removal attributed to the glyphosate concentration as a function of the aluminum dose due to the applied current density. The model is fitted to experimental data to calculate the kinetic and transport parameters.