Remoção de Pb2+ de efluente sintético utilizando a zeólita estilbita natural e argila bentonítica natural.

Abstract

This work stabilized a procedure to remove Pb from an inorganic synthetic effluent, making use of estilbite mineral zeolite and natural bentonite. Were did the characterization of the studied zeolites and bentonites aiming the estimation of the necessary parameters to its utilization on the treatment of inorganic effluents. Experiments were conducted through the use of complete factorial planning of two levels. Based in this planning were possibly analyze the influence of important parameters as pH, treatment and particle size distribution in the retention of lead, having as reference a solution with lead nitrate in a concentration of 100mg/l. The operation conditions most adequate to the zeolite were: pH 4,5, size distribution in the range of 65-100 mesh and treatment with NaCI (2M), and for the bentonite the best conditions were pH 4,5, size distribution in the range of 35-48 mesh and no treatment. Kinetic studies were conducted in a system of finite bath with the best conditions obtained with the factorial planning. Based in the results were constructed charts of concentration as a function of retention time, being possible the determination of the maximum capacity of retention to the zeolite (99,9%) and to the bentonite (99,6%). Even the zeolite as the bentonite removed the lead in the initial time. After the determination of the equilibrium isotherms were determined the constants of equilibrium: Keq = 0,16 to the zeolite and Keq = 0,82 to the bentonite.