Original Articles
Vemula Madhavi, Ambavaram Vija
Abstract
Chromium is an important industrial metal used in various products/processes. Remediation of Cr contaminated sites poses both technological and economic challenges, as conventional methods are often too expensive and difficult to operate. Zero valent iron, an important natural reductant of Cr (VI), is an option in the remediation of contaminated sites, transforming Cr (VI) to essentially nontoxic Cr(III). In the present investigation, an attempt is made to study the efficiency of Fe0 nanoparticles in remediation of Cr contaminated waters. Zero-valent iron (Fe0) nanoparticles were synthesized, characterized, and were tested for removal of Cr (VI) from the water spiked with Cr (VI). Fe0 nanoparticles were synthesized by ferrous sulphate by the reduction of sodium borohydride. The removal efficiency of unstabilised nano Fe0 was compared with Carboxy Methyl Cellulose stabilized Fe0 nano particles. It is observed that the CMC stabilizes the nanoparticles by accelerating the nucleation of atoms during the formation of Fe0 nanoparticles and subsequently forms a bulky and negatively charged layer via sorption of CMC molecules on the Fe0 nanoparticles, thereby preventing the nanoparticles from agglomeration. When a dose of 0.2 g/L of CMCFe0 was used for a sample of Cr(VI) (40 mg/L) 100% degradation was observed but the degradation was only 50% when proceeded with unstabilised Fe0 nano particles. The Cr (VI) removal efficiency was decreased significantly with increasing initial pH. Thus the Iron nanoparticles stabilized with CMC are of a good choice for the remediation of heavy metals in groundwater.