Adsorption of Alizarin Red S Dye on Raw Endoskeleton Nanopowder of Cuttlefish (Sepia Pharaonis) from Water Solutions: Mechanism, Kinetics and Equilibrium Modeling

The potential of the raw cuttlebone nanopowder (CBNP), a biomass waste, as a novel and nontoxic adsorbent for the adsorption of Alizarin Red S (ARS) from water solutions was investigated. To achieve the highest efficiency for the removal of ARS, some affecting factors were optimized. Common techniques (FTIR, FESEM, EDX and XRF) were used to characterize the physicochemical features of the adsorbent. Various kinetic and isotherm models were used to obtain the useful information about the adsorption mechanism of the dye onto the adsorbent. The maximum dye removal efficiency was obtained with the adsorbent amount of 500 mg (in 50 mL) and initial pH of 2 in 10 min for 20 mg/L ARS solution. Under these optimum conditions the complete removal of ARS was obtained while the maximum adsorption capacity was 38.51 mg/g. The well fitness of pseudosecond order kinetic model in the adsorption process was proved by kinetic studies. According to the obtained results, Freundlich isotherm model can suitably describe the adsorption of ARS on the sorbent. The achieved results from this study showed the excellent capability of CBNP for the adsorption of ARS.