Methods of fabrication of zero valent iron nanoparticles (FeNps) are found to affect their efficiency in nitrate removal from water. Application of a 50A/cm2 current to a pair of iron electrodes, in ...distilled water, renders FeNps (37nm) which show twofold efficiency over FeNps (30nm) produced via the reduction of FeSO4 by NaBH4. The approximation of crystallite sizes of FeNps through application of the Scherrer equation to the XRD data suggests a larger size of 39nm (37nm by TEM) associated with the more efficient arc fabricated FeNps, compared to the FeNps produced by the reduction (30nm). On the other hand, scanning electron microscopy (SEM) recommends a higher dispersity for the arc discharged FeNps compared to those produced by NaBH4 reduction. In addition, the XRD pattern of the arc discharge FeNps confirms their purity, whereas Fe3O4 appears as an impurity with the reduction product. Higher concentrations of nitrate retards FeNps produced by reduction while exerts less effect on the arc fabricated FeNps. Hence, using the latter brand is recommended for water sources containing higher concentration of nitrate.
Zero-valent iron nanoparticles (ZVIN) are widely synthesized by several methods in the last decades because it offers indisputable advantages to almost every area of expertise, heavy metal ions ...removal, environmental remediation including for the wastewater treatment. Herein, we report for the first time, the green and eco-friendly synthesis of phytogenic ZVIN using reproducible
Catharanthus roseus
(CR) flower extract for the removal of heavy metal ions including Cr(VI) by adsorption isotherms. The synthesized stable ZVIN were characterized by UV-visible absorption spectroscopy (UV-vis), Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The FT-IR analysis reveals that the polyphenolic compounds that are present in the CR flower extract may be responsible for the reduction and stabilization of the ZVIN. The XRD and SEM-EDX analyses confirmed the phase, composition of elements and morphology of the ZVIN. The synthesized low-cost and non-toxic ZVIN used for the adsorption removal of Cr(VI) from contaminated water; and the Langmuir and Freundlich adsorption isotherms are used to study the adsorption process by the experimental equilibrium adsorption data. The maximum removal of Cr(VI) (98.28%) was observed using optimal conditions of 1.6 g/L of ZVIN concentration, 10 ppm of Cr(VI) concentration, and pH = 4.3 of the initial solution. The adsorption removal of Cr(VI) using the synthesized ZVIN as follows pseudo-second-order kinetic equation with a corresponding correlation coefficient of (
R
2
= 0.99).
