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 ecofriendly
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.