علی اکبر عموئی

Removal of dyestuffs such as Acidic Fuchsine (AF) and Malachite Green (MG) being present in many forms in industries is vital to protect water reservoirs from their catastrophic effects on the ecosystem. This study attempts to effectively eliminate these dyes using a low-cost and eco-friendly material. Eggshell, as a biocompatible by-product, was initially characterized, then some modifications were conducted, and its morphology and chemical structure were then examined through (Atomic force microscopy) AFM, (Fourier-Transform Infrared Spectroscopy) FTIR, (Energy-Dispersive X-ray Spectroscopy) EDS and (Brunauer–Emmett–Teller) BET analyses. They revealed that the modifications on raw material gave rise to a natural nano-adsorbent presenting porous medium appropriate for targeted adsorbate molecules with the average particle size and average pore diameter of 54 and ~2 nm, respectively. Functional groups on the adsorbent surface were also of importance to assist the adsorption of AF and MG. The effect of contact time, adsorbent dose, solution pH and initial concentration was evaluated. Pseudo-second order model accurately correlated the experimental kinetic data for both dyes. Moreover, the participation of intra-particle diffusion along with film diffusion in controlling the process was suggested. Langmuir isotherm model fitted very well to the equilibrium data for both dyes and maximum monolayer adsorption capacity of AF and MG was accordingly calculated to be 5000 and 3333.33mg·g-1 respectively. The inherent characteristics of eggshell make it a potential material to remove contaminants from wastewater in future applications