ANODIC OXIDATION FOR DECONTAMINATION OF CONTAMINATED EFFLUENT WITH GLYPHOSATE HERBICIDE USING BORON DOPED DIAMOND ANODE

Glyphosate is one of the most widely used herbicides in various crops. Based on the existing literature, this herbicide has carcinogenic characteristics, being able to be found in water courses, not only for its leaching in soils, but also in the effluents of the industries that produce it. Due to its negative impact on living beings, this work aims to investigate the applicability of the electrochemical treatment of a synthetic solution containing glyphosate with boron-doped diamond anode. Two electrochemical systems were tested (magnetic stirring and recirculation flow) for studying the applied current density (j = 30-200 mA cm^-2), initial glyphosate concentration (250-850 mg L^-1) and initial pH (3-9) as operating conditions. Best removal efficiencies were achieved at 100 mA cm^-2, 850 mg L^-1 of glyphosate and the natural effluent pH (≈5,0). The performance of the electrochemical systems was evaluated in terms of removal of chemical oxygen demand (COD) and energy requirements. After 120 min of treatment, comparing the magnetic stirring system to the recirculation it was verified that the first one is the most economically viable with an energy consumption of 56 kWh m^-3. However, the results at both electrochemical systems are more efficient than those reported in the literature when the initial concentration, time and mass transport coefficient are considered.

Keywords:
glyphosate; diamond electrode; supporting electrolyte; chemical oxygen demand