A COMPARATIVE STUDY ON ARSENIC (III) REMOVAL FROM AQUEOUS SOLUTION USING NANO AND MICRO SIZED ZERO-VALENT IRON

Abstract

The present study was conducted for Arsenic (III) removal, one of the
most poisonous groundwater pollutants, by synthetic nano and micro size
zerovalent iron (n-mZVI). Batch experiments were performed to
investigate the influence of As (III), nZVI and mZVI concentration, pH
of solution and reaction time on the efficiency of As (III) removal by
Fe0 particles. Nano ZVI was synthesized by reduction of ferric chloride
by sodium borohydrid. Scanning Electron microscope and X-Ray diffraction
were used to determine particle size and characterization of produced
nanoparticles. Results showed up to 99.9% removal efficiency for arsenic
(III) that was obtained by nZVI dosage of 1 g/L at equal time of 10 min
and pH=7. The maximum removal efficiency by mZVI obtained in initial
arsenic concentration of 1 mg/L and mZVI dosage of 10 g/L after 120 min.
and pH=7. It could be concluded that the removal efficiency was
enhanced with increasing n-mZVI dosage and reaction time, but decreased
with increasing of arsenic concentration and pH for both nano and micro
sized ZVI. Nano ZVI presented an outstanding ability to remove As (III)
due to not only a high surface area and low particle size but also to
high inherent activity.