In the current work, a by-product of local olive pomace was valorized as an eco-friendly biosorbent to clear Basic Red 46 dye (BR46). The surface properties of the biosorbent were studied by various analytical implements such as XRF, XRD, FTIR, SEM, and pH_pzc. High removal rates (> 90%) were attained at optimal parameters: 240 min of contact, pH of 7, and 400 rpm at 23 °C. The Freundlich model presented the best adjustment of equilibrium curves, while the pseudo-second-order model was the practical kinetic model that matched the experimental data. The results of the thermodynamic investigation revealed that the adsorption process is spontaneous (ΔG° < 0), exothermic ΔH° (− 40.345 kJ/mol), and probably physical. This study showed that the native olive pomace residue could be successfully transformed into green sorbents of water contaminants.

Graphical Abstract