Evaluation of natural porous material as media filters for domestic wastewater treatment using infiltration percolation process

Before being evacuated to the natural environment, wastewater should be treated first. Since filtration is an essential technique for wastewater treatment, the infiltration percolation (IP) process is utilized in this work. However, traditional IP media filters are typically made of sand. In contrast, our study utilizes six different natural by-products as media filters: crushed seashell, crushed peanut hull, a mixture of sawdust and coal, crushed chicken eggshell, crushed almond shell, and crushed argan nutshell. The aim of this study is to evaluate and compare the effectiveness of these natural support materials in the IP process for treating real domestic wastewater from Rabat, Morocco. To achieve this, six columns were operated in parallel, each filled with one of the six natural materials and loaded with domestic wastewater. Physico-chemical parameters of the wastewater were measured before and after the IP process, and each support material was individually characterized using various techniques. The study conducted in vertical columns revealed that all six materials are effective with good adsorbent properties, making them suitable alternatives for removing organic pollution, as evidenced by a COD reduction of 89–97%. Considering the evaluation of two bed depths, deeper depths produced better results, with the highest COD reduction (97%) observed for the effluent from the column containing crushed seashell media filter. Consequently, our findings can be integrated into project studies, as the value of these materials could contribute to the reduction, recovery, and reuse of waste while treating wastewater.