A novel nanoscale zerovalent iron (nZVI) is an effective adsorbent for
scavenging inorganic and organic toxicants. nZVI was synthesized in a single pot
system using bottom-up approach and were characterized by BET, SEM, EDX and
FTIR. In this study, sorption of Cu2+ onto nZVI was carried out vis-Ã -vis the
investigation of physicochemical parameters (initial metal ion concentration, pH,
temperature, adsorbent dose) at 298 K. The sorption data obtained at optimum
conditions were subjected to six different isotherm models (Langmuir, Freundlich,
Temkin, Dubinin-Raduskevich (D-R), Halsey and Harkin-Jura). However, the
equilibrium sorption data were best described by both Langmuir and Temkin isotherm
models with Langmuir maximum monolayer coverage (Qmax) of 40.816 mg/g and
regression correlation value (R2 > 0.96) supporting a chemisorption mechanism. Pseudo
first-and second-order, Elovich, fractional power and intra-particle diffusion models
were applied to the adsorption data in order to investigate the kinetic process; pseudo
second-order fitted the data most. The intra-particle diffusion model suggested that the
intra-particle diffusion was one of the rate-limiting steps. The values of the Gibbs free
energy showed the feasibility and spontaneity of the sorption process. The removal
efficiency of Cu2+ (> 98%) onto zerovalent iron nanoparticles revealed that nZVI is a
promising and efficient adsorbent that can be utilized by industries on a large scale for
waste treatment.
Keywords: Zerovalent Iron nanoparticle; Sorption; Isotherms; Kinetics and
Thermodynamic