1. 1. J. J. R. Frausto da Silva and R. J. P. Williams, “The Biological Chemistry of the Elements—The Inorganic Chemistry of Life”, 1st ed., 1994, Clarendon Press, Oxford, 541.
2. 2. G. P. Gallios and M. Vaclavikova, Environ. Chem. Lett., 2008, 6, 235.
3. 3. J. O. Nriagu and E. Nieboer, “Chromium in Natural and Human Environment”, 1988, Wiley, New York.
4. 4. P. Metilda, K. Sanghamitra, J. M. Gladis, G. R. K. Naidu, and T. P. Rao, Talanta, 2005, 65, 192.
5. Cr(VI) and Cr(III) removal from aqueous solution by raw and modified lignocellulosic materials: A review