Remoção de cádmio de efluentes sintéticos pela argila bentonita.

Abstract

The removal of cadmium from a synthetic effluent using Primavera and bentonitic clays in two systems, one of finite bath and other using fixed bed column was studied. Studies pointed these materials as promising in Cd2* ions removal in low content synthetic effluent. Tests in finite bath system with initial concentration varying from 18 to 185 ppm at constant pH and temperature of 4,5 and 27 °C respectively, presenting a removal percentage higher than 80%, for the concentration of 18 ppm were realized. The models of Langmuir and Freundlich were applied to the obtained data. The best fit to Primavera claywas obtained using Langmuir model and for Pernambuco clay, was using Freundlich one. For fixed bed assays, the factorial 22 design was used and the increase of the volumetric flow acts negatively in the cadmium removal process while the concentration acts positively. The Primavera clay showed more efficient in finite bath assays as much as in fixed bed column, probably for presenting major superficial area than Pernambuco clay.