Table Olive Wastewater Treatment Using the Clay Mineral Palygorskite as Adsorbent

This study investigated the effectiveness of palygorskite (Pal) as an adsorbent for removing total phenolic content (TPC), dissolved chemical oxygen demand (d-COD), and color from treated olive wastewater (TOW). Experiments were conducted to evaluate the impact of varying Pal dosages (2.5–20 g/L), initial TPC concentrations (80–400 mg/L), and pH (2–9). The results showed that increasing the Pal dosage improved the removal efficiency of TPC and d-COD, though there were diminishing returns beyond 10 g L−1, which indicates equilibrium adsorption behavior. The maximum TPC and d-COD removal reached 68% and 55%, respectively, while color removal exceeded 95% regardless of dosage. Adsorption was most efficient at lower TPC concentrations and an acidic pH (2–3), with up to 85% TPC removal. This suggests that pH-dependent phenolic ionization enhances Pal adsorption. Color removal remained consistently high across all conditions, highlighting palygorskite’s mesoporosity and affinity for chromophoric compounds. These findings affirm the potential of Pal as a cost-effective and versatile adsorbent for TOW treatment.