Adsorption of malachite green using waste marine cuttlefish bone powder: Experimental and theoretical investigations

Adsorption remediation is an energy-efficient water treatment technology that utilizes the adsorption properties of a biosorbent to remove various pollutants. While many articles have explored the high surface area and adsorption capacity of activated carbon for remediating aquatic systems, few have delved into the environmental impact of its synthesis, which often involves H3PO4, a highly toxic activating agent. In this study, we present a groundbreaking alternative to activated carbon for the adsorption and remediation of aquatic waste that doesn't rely on chemical products. Our discovery that cuttlefish bone, typically considered waste, can serve as an effective adsorbent is a significant leap in eco-friendly research and a source of inspiration for future sustainable solutions. We selected Malachite Green (MG) as a cationic toxic dye to evaluate the adsorption capacity of our green adsorbent. The prepared powder underwent characterization using techniques such as FTIR, XRD, SEM, and elemental analysis. Additionally, the determination of the cuttlefish bone's zero-point charge pH revealed a value of 8.4, which influences the material's surface charge and its interaction with ions and molecules in the solution. We conducted a detailed study on the effects of solution pH, adsorbent amount, Malachite Green concentration, temperature, and contact time on the dye adsorption. The results demonstrated that the adsorption of Malachite Green by cuttlefish bone powder is an endothermic process, requiring heat input. This indicates that the adsorption efficiency increases with temperature. The significant enthalpy results obtained confirmed the endothermic nature of the process. In this study, we combined experimental and theoretical approaches to gain a better understanding of the adsorption mechanism. The results showed that Cuttlefish Bone is an environmentally friendly and highly efficient adsorbent.