Characterization of the complex metal-clay obtained in the process of lead adsorption

Abstract

This study aims to characterize the complex metal-clay formed by adsorption of lead. In this work, the bentonite clay named Fluidgel was calcined at 750 °C and was used as adsorbent for lead removal. The characterization of this clay and complex metal-clay was carried out by X-ray diffraction (XRD), Fourier transformer infrared spectroscopy (FTIR), surface area (BET method), scanning electron microscopy (SEM) and chemical composition by energy dispersive X-ray (EDX). The removal of lead from aqueous solution was carried out in a fixed bed. Dynamic experiments were performed to evaluate the effect of flowrate on adsorption efficiency. The experiments were accomplished at room temperature, the clay adsorbent particle diameter was of 0.855 mm and the flow rate varied from 0.6 to 2 mL/min. The feed concentration of lead was about 0.24 mmol/L. Comparing the chemical compositions of the clays obtained by EDX before and after removal of the lead, it was concluded that the ion exchange process might be important to lead removal. From the semi-quantitative analysis of chemical composition in clays with and without adsorbed lead it was observed a reduction of the amount of Ca 2+ , K + cations and the disappearance of Na + cations, which was caused by cation exchange process.

Adsorption of mesitylene via mesoporous adsorbents

“…To examine the effect of relative humidity, a humidifier is installed, and the humidity is controlled by adjusting the gas flow rate of the humidifier and the feed rate of airflow. In this study, the breakthrough point (BP) and saturation point (SP) are defined as the times required for the effluent mesitylene concentration to reach 5% and 95% of the influent concentration, respectively, and they are used as references for comparison (Vieira et al, 2014). Hence, the breakthrough and saturation times are estimated from the start of the adsorption tests to the BP and SP, respectively.…”