SiO2 immobilized polyphenols from yerba mate (Ilex paraguariensis) as heavy metal biosorbent

G. J. COPELLO; M. P. PESENTI; F. VARELA; M. RAINERI; A. M. MEBERT; L. E. DÍAZ

Puerto Madryn, Chubut

Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2010

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

p { margin-bottom: 0.21cm; }a:link { color: rgb(0, 0, 255); } The control of industrial effluents and polluted waters has motivated the development of assorted solutions. The low cost sorbents are an alternative to the traditional and more expensive methods, such as ion exchange resins. Low cost sorbents are those that require little or non processing and are typically abundant industrial secondary products or wastes. The biosorbents are low cost sorbents obtained from a biological source, such as saw dust or rise husk. Some vegetable biosorbents have the capability of adsorbing heavy metals. This is related to polyphenolic compounds that interact with the metals within the plant. In this work, by means of the Sol-gel chemistry, a polyphenol extract had been immobilized within a SiO2 network. The SiO2 polymers give the biosorbent a mechanical support for its application and removal from polluted waters. As source of polyphenols, the residual dust of yerba mate (Ilex paraguariensis) production was used. Tetraetoxy silane was chosen as SiO2 precursor and glutaraldehide has been used as the crosslinking agent. The biosorbent obtained were able to remove Pb(II), Cr(III) and Cr(VI) from contaminated solutions at acidic pHs were it is know that the polyphenol-metal complex is stronger. A kinetic and adsorption capacity analysis (Langmuir, Freunlich, Dubinin-Radushkevich) are presented with the characterization of the material (SEM, BET).