Adsorption of zinc and copper (II) ions from aqueous solution using modified nano bentonite: equilibrium, kinetics, and thermodynamic studies

Sustainable robust green synthesis of nanoparticles from waste aquatic plants and its application in environmental remediation

Green synthesis of nanoparticles using natural materials is an emerging technique that fascinates the scientific community globally for the treatment of wastewater. In the present study, aquatic plants such as Piaropus crassipes (PC) and Lemna gibba (LG), were utilized to make low-cost nanoparticles, and its feasibility for the removal of Zn(II) ions was studied. The synthesized nano adsorbents were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and zeta potential analysis. The optimal conditions were evaluated by batch adsorption studies, to investigate the parameters such as pH (2-7), adsorbent dosage (0.5-5 g/L), initial concentration (20-60 mg/L), and contact time (10-120 min) etc. The isotherm, and kinetic data results fit well with Langmuir, and pseudo-second order models. The anticipated monolayer adsorption capacity with respect to the PC, and LG was found to be 42.41 mg/g and 27.65 mg/g, respectively. Thermodynamic studies showed that the process is exothermic. The adsorption mechanism of PC/LG on Zn(II) exhibited surface complexation, ion exchange, and diffusion. Desorption studies were performed to analyze the recovery potential of Zn(II) ion. Hence, this article investigates the economic synthesis of green nanoparticles, and their potential utilization in heavy metal remediation.