Treatment of highly saline effluents laden with organic pollutants using ceramic ultrafiltration membranes and application to leachate treatment

The aim of this study is to assess the efficacy of three ultrafiltration ceramic membranes with distinct porosities (20, 50, and 100 nm) in treating highly charged effluents and their potential application in leachate treatment. In the initial phase, Response Surface Methodology (RSM) was employed using a solution containing NaCl (TDS = 20 g/L) and glucose (mass concentration (Cm) = 10 g/L). The investigation focused on operational parameters, specifically Circulation velocity (CV) and volumetric concentration factor (VCF). The responses considered encompass permeate flux (PF) and retention (R). In the subsequent phase, as part of a practical application, leachate was subjected to treatment, and the fouling mechanisms specific to each membrane were identified. The Hermia model was employed, distinguishing between four fouling modes: cake formation, intermediate blocking, pore constriction, and complete blocking. The results demonstrate that, during the treatment of the synthetic solution, VCF has a more significant influence on both responses compared to CV. Furthermore, CV impacts the critical flux of the three membranes, without affecting the retention of suspended matter (SS). When treating the leachate, removal efficiencies of 55%, 51%, and 47% for COD and 36%, 33%, and 29% for SS were achieved for membranes with porosities of 20 nm, 50 nm, and 100 nm, respectively. Modeling the flux over time showed that fouling of these three UF membranes is superficial, and the main fouling mechanism is cake formation.