Our work is based on using a new natural biodegradable adsorbent derived from natural residues (walnut shells) for the retention of humic substances (HS).The synthesis of obtaining the organic material is: cleaning, drying, grinding, sieving and finally heat treatment and chemical activation by lemon acid and phosphoric acid (H3PO4). Various reaction parameters were examined to determine the optimal conditions for effective adsorption of the specific pollutant. When the mass of the material is 20 mg in solution, we see an increase in the yield of adsorption (R%=92%) at temperature of 40 °C and stirring speed of 300 rpm. The pseudo-second order model is better suited to explain how humic substance (HS) is adsorbed on activated Nutshells. The examination of the isotherm indicates that the Freundlichis well than Langmuir models represent the adsorption process of the humic substance, with a substantial linear correlation coefficient of 98.5%. The thermodynamic properties, namely the enthalpies, entropies, and free energies (ΔH°, ΔS°, ΔG°), of HS adsorption were quantified.

Treatment, Pollution, Humic substance, Environment, Reaction parameters.