Urban wastewater treatment by coupling infiltration–percolation and electrocoagulation processes for reuse

Given the increasing demand for water resources and the challenges of climate change, wastewater reuse emerges as a crucial solution. Particularly in arid and semi-arid regions where water resources are limited, wastewater reuse plays a vital role by providing a sustainable source for agriculture and other purposes, necessitating the development of innovative and economically viable treatment technologies. The primary objective of this study is to evaluate the effectiveness of coupling infiltration–percolation (IP) and electrocoagulation (EC) processes using aluminum plates to remove organic, nitrogenous, and microbial pollutants from secondary effluents at Gabès waste water treatment plant. To assess the efficiency of this hybrid process, the secondary effluents were first treated using the infiltration–percolation method, followed by electrocoagulation with alternating power source. The current intensities used were 100 mA, 200 mA and 500 mA, with treatment times of 15, 30, 45, 60 and 75 min, respectively, using two aluminum electrodes. The results showed that the optimal time and intensity for reducing organic, nitrogenous and microbial pollutants in urban wastewater were 75 min and 500 mA of current, respectively. The results obtained under optimized conditions demonstrate that coupling these two processes achieved satisfactory outcomes. The reduction rates were 100% for turbidity, COD, PO43−, NH4+, and NO3−. In addition, a complete elimination of fecal contamination indicator bacteria, including total coliforms, fecal coliforms and enterococci, was observed.