Nanoscale zero-valent iron for aqueous lead removal

Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method.  These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering, scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR). The NZVI optical energy band gap as calculated by UV absorption spectrum was 1.7 eV. The zeta potential was obtained as -32.0 mV. The biocompatibility test of NZVI was performed using MTT assay on MDCK-2 as model cell lines. Lead adsorption on NZVI was examined at different pHs, equilibrium time, temperature, and NZVI/Pb2+ concentrations. Almost 100% Pb2+ removal was achieved at NZVI dose: 0.4 g/L;Pb2+ concentration: 50 mg/L; equilibrium time: 15 min; pH 5-6; and temperature: 25°C. Pb2+ sorption kinetic data were fitted to pseudo-first and second-order kinetic equations. Pseudo-second-order kinetic equation best fitted the data.  These studies clearly demonstrate NZVI as an efficient nano-adsorbent for Pb2+ removal from water. Copyright © 2017 VBRI Press