Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2013, 5(9):123-129 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 123 Study on reduction of hexavalent chromium in aqueous solution using GT-Fe 0 nanoparticles Sakcham Bairoliya 1 , Swati Dubey 1 , Sohini Bagchi 1 , Rajasekaran R. 2 , Ramanathan K. 2 and Shanthi V. 1* 1 Industrial Biotechnology Division, School of Bio Sciences and Technology, VIT University, Vellore, Tamil Nadu, India 2 Bioinformatics Division, School of Bio Sciences and Technology, VIT University, Vellore, Tamil Nadu, India _____________________________________________________________________________________________ ABSTRACT Cr(VI) is a contaminant in various resources that is used by man in daily life, for e.g. soil ground water, river water, vegetables grown in such soil etc. it is a heavy metal, consumption of which might cause fatality to the consumer. It is seen that iron nanoparticles are able to reduce this Cr(VI) to its trivalent ion Cr(III) which is much less harmful. This article deals with the use of Iron Nanoparticles biosynthesized from green tea (GT) for its possible application in reducing toxicity and pollution caused by Cr(VI). The method used is a batch method where we get a number of similarly proceeding reaction which do not interfere with each other. The decrease in concentration of the standard solution of K 2 Cr 2 O 7 on addition of iron nanoparticles is used as an indicator of reduction of Cr(VI) to Cr(III). It is seen that the GT Fe-NPs remove Cr(VI) from the solution with good efficiency and may have good future prospects as an antipollution measure. Keywords: iron nanoparticles, hexavalent chromium, reduction, Cr(VI), Cr(III) _____________________________________________________________________________________________ INTRODUCTION Hexavalent chromium, Cr(VI), refers to chemical compounds that contain the element chromium in the +6 oxidation state [1].It is very toxic and mutagenic when inhaled. Cr(VI) has not been established as a carcinogen when in solution, although it may cause Allergic Contact Dermatitis (ACD)[2, 3,]. The two environmentally stable oxidation states of chromium, Cr(VI) and Cr(III), exhibit very different toxicities and mobility’s. Cr(VI) and Cr(III)compounds differ in their health and environmental effects, with Cr(VI) being far more dangerous. Ingesting small to moderate amounts of Cr(III) is essential to human metabolism, and there is no current evidence that Cr(III) is carcinogenic. In contrast, exposure to Cr (VI) is known to be a serious human health risk [4, 5]. Cr(VI) does not readily precipitate or become bound to components of soil, therefore, Cr(VI) can move throughout aquifers to contaminate groundwater and other sources of drinking water [6,7]. On the other hand, Cr(III) is relatively insoluble in aqueous systems, much less toxic and even essential in human and animal nutrition The World Health Organization(WHO), the International Agency for Research on Cancer(IARC), and the Environmental Protection Agency(EPA) have determined that Cr(VI) compounds are known human carcinogens. The Lucinda valley in Jaipur District, Orissa, is known for its deposit of chromite ore, producing nearly 98% of the chromite ore in India and one of the prime open cast chromite ore mines in the world (CES, Orissa Newsletter). Due to the seepage of water from the dumped wastes, the nearby water stream gets contaminated with Cr(VI) at a concentration much above the permissible limits. Such incidents happen all over the word. The main diseases include gastrointestinal bleeding, tuberculosis, asthma, infertility, birth defects, and stillbirths. Sources of Cr(VI)