Comparative analysis of 15% and 20% NaOH modified kaolinite clay samples

Abstract

This study investigated the effects of 15% and 20% NaOH treatment on clay samples with the aim of improving the surface characteristics and adsorption capacity for wastewater treatment. The morphological, chemical composition and molecular properties of the raw and modified clay samples were analyzed using scanning electron microscopy coupled energy dispersive Xray spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR). The results obtained showed that the 15% and 20% NaOH treatment improved the surface properties of the clay samples. Additionally, the absence of peak at 3059 cm^-1 in the raw clay spectrum was notable in the FTIR spectra, as it corresponds to O-H bending due to adsorbed water. Also, a similar outcome was observed for 15% and 20% modified clay samples, the peaks observed between 3200-2500 cm^-1 indicated O-H stretching vibration, while those between 2160-2120 cm^-1 signify -N stretching vibration. Thus, we believe the modification of surface properties of the modified clay samples will improve the adsorption capacity of different contaminants present in wastewater.