Evaluation of a Hybrid System of Continuous Electrocoagulation–Sedimentation in an Imhoff Tank for the Treatment of Sugar Effluents

Mexico’s highly biodiverse agro-industrial sector is a cornerstone of its economy, prominently featuring a robust sugarcane industry that ranks seventh globally in sugar production. This industry utilizes 52% of the country’s industrial water resources, hence producing substantial quantities of complex wastewater. To address this critical environmental challenge, this study evaluates a continuous electrocoagulation process applied to sugarcane mill effluents. The study examines the effectiveness of removing essential water quality indicators, chemical oxygen demand (COD), turbidity, and total solids (TSs), total suspended solids (TSSs), and total dissolved solids (TDSs), by evaluating the influence of the hydraulic retention time (HRT) and current intensity. Investigations were performed in a 20 L continuous-flow Imhoff reactor fitted with aluminum electrodes. Ideal operational parameters were attained with a hydraulic retention time of 120 min and a current intensity of 1.5 amperes. Within these parameters, the system attained notable removal efficiencies: 69% for COD, 78% for turbidity, 60% for total solids, 94% for suspended particles, and 55% for dissolved solids. These findings indicate that the incorporation of continuous electrocoagulation into an Imhoff tank design offers a highly efficient and scalable first treatment to reduce the ecological effects of sugarcane agro-industrial effluents.