Removal of Azo Dye Carmoisine by Adsorption Process on Diatomite

This work aims to evaluate the adsorption capacity of an abundant natural diatomite (ND) remove azo dye carmoisine, known as a harmful emerging organic pollutant. Indeed, best our knowledge, no results were reported on this subject. The ND was characterized by FTIR, XRD, and SEM/EDX analyses. experimental study carried out in batch mode. Results showed that adsorbent is mainly composed silica. A fraction calcite ankerite also identified. It porous material with specific surface about 41 m2.g-1 hydroxyl functional group -OH. Adsorption process found be effective removing carmoisine colorant. strongly affected adsorbate contents, solution pH, temperature, water hardness mineralization. At room optimal conditions for highest (12 mg.g-1) colorant concentration 50mg.L-1, pH 2, contact time 30min, content 1 g.L-1. Modeling has are well modeled Freundlich isotherm multilayer adsorption. reaction kinetics pseudo-second order, thermodynamic parameters indicated nature endothermic spontaneous.