Removal of Cationic Dye from Aqueous Solution using Agricultural Wastes: Argan and Almond Shells

In this work, Crystal Violet (CV), cationic dye, is removed from aqueous solution, using wood of Argan shell (ARS) and Almond shell (ALS), as low-cost and eco-friendly biosorbants. The parameters influencing the adsorption of CV on each of our adsorbents, contact time (5–180 min), adsorbent dose (0.2–2 g), pH of the solution (3–11), temperature (20–50°C) and the initial dye concentration (50–500 mg.L-1), were investigated. The modeling of experimental results obtained, showed that the CV adsorption on both biomaterials followed a pseudo-second-order kinetic and in perfect agreement with Langmuir isotherm. Also , at 40 ° C, CV is better adsorbed on ALS that ARS, with maximum biosorption amounts 51.99 mg.g-1 and 37.32mg.g-1, respectively. Thermodynamic calculations have shown that the sorption is spontaneous, endothermic and random at the solid / solution interface. Adsorption capacities of dyes by ARS and ALS were better or comparable to those of several other biomaterials already studied. ALS and ARS biomaterials studied can be considered as alternative biosorbants low-cost and eco-friendly.