Resumen de Potentiometric Demonstration of Metal Biosorption by Nonliving Plants
Litza Halla Velázquez Jiménez, Luz María Torres Rodríguez, Ramón Fernando García de la Cruz, Antonio Montes Rojas, Rafael Eduardo López Arteaga
An electrochemical experiment is presented to illustrate biosorption to second-year and upper-division undergraduate students. The extraction of Cd2+, Pb2+, and Cu2+ by nonliving Typha latifolia (cattail) roots can be monitored in real time by potentiometry determinations. The open circuit potential (OCP) for the metal in equilibrium with its ion is measured before, during, and after plant addition to a solution. Decrease in OCP indicates a reduction in the metal concentration in solution because of the metal uptake by the plant. The quantity of metal accumulated in the plant and the variation in the OCP can be calculated from the Nernst equation. This experiment is simple and pedagogical.
