Otimização de parâmetros operacionais no tratamento eletroquímico descentralizado de efluente real contendo glifosato

Abstract

Electrochemical treatment of wastewater is a promising alternative for reducing organic pollutant loads. Glyphosate herbicide is widely used in agriculture, and the washing of its containers generates significant volumes of hazardous wastewater. This study investigated the optimal conditions for the electrolysis of a real glyphosate-contaminated effluent, considering treatment time, energy consumption, and operational costs. The experiments were carried out using a flow-through electrochemical reactor equipped with a boron-doped diamond (DDB) anode. A factorial design was employed to evaluate the effects of current density (10–30 mA cm⁻²) and initial organic load (100–300 mg TOC L⁻¹). Total organic carbon (TOC), chemical oxygen demand (COD), and cell potential were monitored throughout the experiments. The use of a low-cost turbulence promoter improved mass transfer, increased mineralization efficiency, and reduced energy consumption, while temperature control showed minimal influence. The application of a current density of 30 mA cm⁻² provided the best balance between treatment time and energy efficiency. Predictive models were developed to estimate electrolysis time and energy consumption. Operational costs ranged from USD 1.71 m⁻³ to USD 7.09 m⁻³, with values between USD 3.55 m⁻³ and USD 4.37 m⁻³ obtained for effluents containing 300 mg TOC L⁻¹ treated at 10–30 mA cm⁻², demonstrating the feasibility of the process even under conditions of high organic load. These results contribute to the development of optimized and economically viable electrooxidation systems for the treatment of pesticide-contaminated wastewater, supporting the sustainable management of agricultural wastewaters.