: Removal of PB (II) and CR (III) CATIONS from aqueous solutions using natural ZEOLITE

Abstract

The removal of inorganic toxic heavy metals from water and its softening by using natural zeolites are widely used in the purifications treatment of water. Here within, the adsorption of Pb2+ and Cr3+ ions from an aqueous solution by Cuban (Tasajeras) natural zeolite (Clinoptilolite) with 150µm particle size were studied through batch experiment method. Optimization of contact time, zeolite dose, heavy metal ions (Pb2+ and Cr3+ ions) concentration and temperature were carried out to be 4hrs, 1g, 10ppm and 250C respectively. Optimization of initial pH was also done and found to be 4 for Pb2+ and 5 for Cr3+. Then, at these obtained optimum parameters and 260 rpm agitation speed, the removal efficiency of this natural zeolite was found to be 97.6% for Pb2+ and 98.7% for Cr3+. Adsorption isotherm study using Langmuir and Freundlich model were considred and the data best fit with the Langmuir adsorption isotherm model. Keywords: - Natural Zeolite ( Clinoptilolite), lead ion (Pb2+), chromium ion (Cr3+), Batch Adsorption Method, Adsorption Isotherm, Co-existing ions.