Estudo da remoção de metal pesado (níquel) de efluentes contaminados utilizando argila nacional.

Abstract

The aim of this work is to characterize chocolate clay (Boa Vista, PB) in its natural form and after thermal activation (300, 400 and 500 °C) by evaluating its potentiality as an adsorbent in the process of nickel extraction in a finite bath system. In the first part the clays were characterized by Ion Exchange Capacity (IEC), X-ray Diffraction (XRD), X-ray Spectrophotometry by Dispersive Energy (EDX), Differential Thermal Analysis (DTA) and Themogravimetric Analysis (TGA), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM). The thermal activated clays showed difference in all tests. In the second stage of the research the proceeding of NP+ extraction was established based on a synthetic inorganic effluent by using thermally activated chocolate clays. The 2 3 factorial planning with 3 experiments in the central point was used to evaluate the influence of the main parameters such as temperature (300, 400 and 500 °C), mean diameter of particle (0,337, 0,567 and 0,855 mm) and initial nickel concentration (30, 60 and 90 ppm) over Ni2+ extraction. The variables that most influenced the adsorption were temperature (400 °C) and initial concentration (30 ppm). The data obtained from the factorial planning was better adjusted to the quadratic model used in MINITAB 13.1, hence obtaining the significance regression of 95% confidence.