Green synthesis of bio-functionalized nano-particles for the application of copper removal – characterization and modeling studies

Green technology for the synthesis of nanoparticles has gained momentum due to its cost-effectiveness and eco-friendly nature. In this research study, silver nanoparticles (AgNps) were synthesized using an eco-friendly biological method involving the use of marine algae, Halimeda gracilis. The surface properties of the synthesized silver nanoparticles were studied using UV–visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy methods. During the synthesis of nano particles, the parameters namely temperature (30 °C to 90 °C), pH (6–10), silver nitrate (AgNO3) concentration (1–3 mg/ml) and quantity of algal extract (1–3 ml) were optimized to improve the production of AgNPs. The application of the synthesized silver nanoparticles for the adsorptive removal of copper from aqueous and industrial wastewater was investigated. Intra-particle diffusion mechanism was identified to be controlling step in metal removal. Regeneration of sorbent was carried out using 2.0 M HCl and the reusability was verified for 6 cycles. A removal efficiency of copper (64.8%) from electroplating wastewater demonstrated the industrial application potential of the synthesized silver nanoparticles. •Green synthesize of silver nano particles (AgNPs) was carried out using Halimeda gracilis.•SEM, FTIR, TGA and UV Spectra were employed to characterize the synthesized AgNPs.•A maximum production of 2.72 g of AgNPs/100 ml of Halimeda gracilis was attained.•Isotherm, kinetics, desorption and regeneration studies were performed.•Equilibrium copper uptake capacity of AgNps was 46.30 mg/g.