Abstract
Pollutants found in the wastewater streams of industrial processes such as heavy metals are a significant concern worldwide. Clays are low-cost sorbents that have attracted extensive research interest due to their potential applications in removing heavy metals from wastewater. In this work, montmorillonite clay was collected from the Bengurir region; Morocco was used as an eco-friendly adsorbent for the removal of chromium (III) at various operating conditions. The used adsorbent was characterized using X-ray diffraction, X-ray fluorescence spectrometry, Fourier Transform Infrared Spectroscopy, and scanning electron microscope coupled with X-ray energy dispersion spectrometer analysis. Effects of adsorbent dose, initial concentration, and pH were investigated to optimize the adsorption process. The controlling mechanism and the potential rate-limiting steps were analyzed using Lagergren's pseudo-first-order and pseudo-second-order models, but the experimental data were better fitted to the pseudo-second-order equation. The equilibrium isotherm data were analyzed by applying Langmuir and Freundlich's isotherm models, and Langmuir showed good fits with the experimental data. A maximum Cr(III) adsorption capacity of 7.5 mg g(-1) was found in the studied conditions.