Edvina Lamy

To quantify water flow occurring in filter beds employed during wastewater treatment, laboratory column tracer experiments were performed on natural low‐cost adsorbents (charcoal, oyster shell, and argan nutshell) under saturated flow conditions. The columns were packed with 100 % of adsorbents and with multi‐sand‐layer (MSL) system, consisting of permeable layers of pozzolan alternated with mixed layers (sand + adsorbent + sawdust). The results showed a more uniform flow in 100 % adsorbents for charcoal and oyster shell compared to their respective MSL columns. Conversely, flow uniformity was slightly improved in MSL versus 100 % adsorbent for argan nutshell columns. The choice of the appropriated adsorbent is crucial for the improvement of flow uniformity and treatment efficiency.