Novel green magnetite-chitosan adsorbent using Ricinus communis plants to adsorption of lead (II) from wastewater solution: anodic linear sweep voltammetry, isotherms, and kinetics study

Abstract

This study centered on removing toxic Pb (II) ions from wastewater using Fe₃O₄ with natural biopolymer chitosan and green plant extracts from Ricinus communis (Castor plant) to synthesize a novel magnetic chitosan nano-composites (GCS-Fe₃O₄) adsorbent. The nano-material was synthesized using the co-precipitation method and characterized using FTIR, XRD, FESEM, TEM, SEM, AFM, TGA-DTA, DLS, UV–Vis, and VSM. The green-synthesized nanocomposites (GCS-Fe₃O₄) have been used to remove Pb (II) from a wastewater solution. A study was conducted on the experimental parameters, such as the pH range, contact time, adsorbent dosage, and temperature effects, the highest capacity of adsorption Pb (II) ions observed at a pH 6.8, a temperature of 30℃, a contact time of 60 min., with an adsorbent dose of 0.30 g/L. The maximum removal of Pb (II) ions was 99.2%, obtained at a concentration of 0.30 g/L. The Freundlich isotherm stipulated the most precise simulation of the adsorption equilibrium. The maximum adsorption capacity was determined to be 48.64 mg/g at 30℃ using the Freundlich isotherm. The pseudo-second-order kinetic model most accurately represented the adsorption kinetics of Pb (II). In contrast, thermodynamic data shows an endothermic adsorption process with temperature, the adsorption efficiency also increases to 5.35, 7.17, and 8.90 kJ/mol respectively. The Pb (II) ions were determined by 797 VA anodic linear sweep voltammetry Computrace (Metrohm). Hence, the synthesized green magnetite chitosan composite (GCS-Fe₃O₄) is suitable for removing Pb (II) ions from wastewater solutions.